Sample records for needle tip locations
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Puder, Jardena J; Atar, Michael; Muller, Beat; Pavan, Marco; Keller, Ulrich
2005-02-01
Reusing insulin pen needles could help to reduce the increasing economic burden of diabetes. We tested the hypothesis that reusing insulin pen needles leads to needle tip deformity and increased pain. Three blinded reviewers assessed 123 electron microscope pictures analyzing needle tip deformity of insulin pen needles used up to four times by diabetic subjects and up to five times by blinded non-diabetic volunteers. The estimated frequency of needle use was correlated to the actual number of needle use. Pain intensity and unpleasantness of each injection were measured by a visual analogue scale and their differences analyzed by Kruskal-Wallis analysis of variance. Unused needles could be differentiated visually from used needles. However, there was no correlation between the actual and guessed number of times a needle was used (r = 0.07, P = 0.2). Evaluating all 270 injections, neither pain intensity nor unpleasantness increased with repeated injections of the same needles in people with diabetes (P = 0.1 and 0.96) and in the volunteers (P = 0.63 and 0.92). Using pen needles four to five times does not lead to progressive needle tip deformity and does not increase pain intensity or unpleasantness, but could increase convenience and lead to substantial financial savings in Europe of around EUR 100 million/year.
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Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice.
Scholten, H J; Pourtaherian, A; Mihajlovic, N; Korsten, H H M; A Bouwman, R
2017-07-01
Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging structures not visible on the ultrasound screen. Additional techniques specifically developed to aid alignment of needle and probe or identification of the needle tip are now available. In this scoping review, advantages and limitations of the following categories of those solutions are presented: needle guides; alterations to needle or needle tip; three- and four-dimensional ultrasound; magnetism, electromagnetic or GPS systems; optical tracking; augmented (virtual) reality; robotic assistance; and automated (computerised) needle detection. Most evidence originates from phantom studies, case reports and series, with few randomised clinical trials. Improved first-pass success and reduced performance time are the most frequently cited benefits, whereas the need for additional and often expensive hardware is the greatest limitation to widespread adoption. Novice ultrasound users seem to benefit most and great potential lies in education. Future research should focus on reporting relevant clinical parameters to learn which technique will benefit patients most in terms of success and safety. © 2017 The Association of Anaesthetists of Great Britain and Ireland.
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Detection of Membrane Puncture with Haptic Feedback using a Tip-Force Sensing Needle.
Elayaperumal, Santhi; Bae, Jung Hwa; Daniel, Bruce L; Cutkosky, Mark R
2014-09-01
This paper presents calibration and user test results of a 3-D tip-force sensing needle with haptic feedback. The needle is a modified MRI-compatible biopsy needle with embedded fiber Bragg grating (FBG) sensors for strain detection. After calibration, the needle is interrogated at 2 kHz, and dynamic forces are displayed remotely with a voice coil actuator. The needle is tested in a single-axis master/slave system, with the voice coil haptic display at the master, and the needle at the slave end. Tissue phantoms with embedded membranes were used to determine the ability of the tip-force sensors to provide real-time haptic feedback as compared to external sensors at the needle base during needle insertion via the master/slave system. Subjects were able to determine the position of the embedded membranes with significantly better accuracy using FBG tip feedback than with base feedback using a commercial force/torque sensor (p = 0.045) or with no added haptic feedback (p = 0.0024).
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Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice
Scholten, H.J.; Pourtaherian, A.; Mihajlovic, N.; Korsten, H.; Bouwman, R.A.
2017-01-01
Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging
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Shipley, Kyle; Riew, K. Daniel; Gilula, Louis A.
2013-01-01
Study Design Retrospective evaluation of consecutively performed fluoroscopically guided cervical nerve root blocks. Objective To describe the incidence of injectate central epidural flow with respect to needle tip position during fluoroscopically guided extraforaminal cervical nerve root blocks (ECNRBs). Methods Between February 19, 2003 and June 11, 2003, 132 consecutive fluoroscopically guided ECNRBs performed with contrast media in the final injected material (injectate) were reviewed on 95 patients with average of 1.3 injections per patient. Fluoroscopic spot images documenting the procedure were obtained as part of standard quality assurance. An independent observer not directly involved in the procedures retrospectively reviewed the images, and the data were placed into a database. Image review was performed to determine optimal needle tip positioning for injectate epidural flow. Results Central epidural injectate flow was obtained in only 28.9% of injections with the needle tip lateral to midline of the lateral mass (zone 2). 83.8% of injectate went into epidural space when the needle tip was medial to midline of the lateral mass (zone 3). 100% of injectate flowed epidurally when the needle tip was medial to or at the medial cortex of the lateral mass (zone 4). There was no statistically significant difference with regards to central epidural flow and the needle tip position on lateral view. Conclusion To ensure central epidural flow with ECNRBs one must be prepared to pass the needle tip medial to midplane of the lateral mass or to medial cortex of the lateral mass. Approximately 16% of ECNRBs with needle tip medial to midline of the lateral mass did not flow into epidural space. One cannot claim a nerve block is an epidural block unless epidural flow of injectate is observed. PMID:24494176
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Zheng, Dandan; Todor, Dorin A
2011-01-01
In real-time trans-rectal ultrasound (TRUS)-based high-dose-rate prostate brachytherapy, the accurate identification of needle-tip position is critical for treatment planning and delivery. Currently, needle-tip identification on ultrasound images can be subject to large uncertainty and errors because of ultrasound image quality and imaging artifacts. To address this problem, we developed a method based on physical measurements with simple and practical implementation to improve the accuracy and robustness of needle-tip identification. Our method uses measurements of the residual needle length and an off-line pre-established coordinate transformation factor, to calculate the needle-tip position on the TRUS images. The transformation factor was established through a one-time systematic set of measurements of the probe and template holder positions, applicable to all patients. To compare the accuracy and robustness of the proposed method and the conventional method (ultrasound detection), based on the gold-standard X-ray fluoroscopy, extensive measurements were conducted in water and gel phantoms. In water phantom, our method showed an average tip-detection accuracy of 0.7 mm compared with 1.6 mm of the conventional method. In gel phantom (more realistic and tissue-like), our method maintained its level of accuracy while the uncertainty of the conventional method was 3.4mm on average with maximum values of over 10mm because of imaging artifacts. A novel method based on simple physical measurements was developed to accurately detect the needle-tip position for TRUS-based high-dose-rate prostate brachytherapy. The method demonstrated much improved accuracy and robustness over the conventional method. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Lyubomyr Lytvynchuk
Full Text Available A comparison of the cellular content of needle tip aspirates and entry sites after transconjunctival intravitreal injection (IVI using different needle types was performed. White outbred rats and human cadaver eyes were used for IVI by hypodermic 27 gauge (G and 30G needles, and spinal anesthesia Pencan 27G needles. Aspiration of vitreous for quantitative morphological and cell cultivation analysis, as well as cyto-histological analysis of aspirates and entry sites were carried out. The most common cells in the aspirates from all needle types were conjunctival epithelial-, ciliary body non-pigmented epithelial- and sclerocyte-like cells and granular proteins. Crystallized vitreous specimens were present in each aspirate. The entry sites of hypodermic needles showed marked trauma in all wall layers of rat and human eyes accompanied by cellular destruction and hemorrhages. Pencan 27G needle caused less tissue trauma with partial reposition of sclerocytes. Transconjunctival IVIs with hypodermic 27G and 30G, and Pencan 27G needles result in trauma of all layers of the eyeball. The possible consequences of cellular content being cut and injected into the eye, as well as the entry site wound shape deserve future consideration and improvements.
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Cazzato, Roberto Luigi; Garnon, Julien; Shaygi, Behnam; Caudrelier, Jean; Bauones, Salem; Tsoumakidou, Georgia; Koch, Guillaume; Gangi, Afshin
2017-09-01
To present a new blunt-tip coaxial needle (SoftGuard) applied to access "hard-to-reach" targets undergoing percutaneous image-guided biopsy or drainage. All consecutive patients presenting between August and December 2016 with "hard-to-reach" (blunt-tip needle is a safe and effective tool when applied as a coaxial working cannula for percutaneous biopsy or drainage of "hard-to-reach" targets.
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Directory of Open Access Journals (Sweden)
Hiromi eSato
2011-07-01
Full Text Available Pseudomonas aeruginosa possesses a type III secretion system (T3SS to intoxicate host cells and evade innate immunity. This virulence-related machinery consists of a molecular syringe and needle assembled on the bacterial surface, which allows delivery of T3 effector proteins into infected cells. To accomplish a one-step effector translocation, a tip protein is required at the top end of the T3 needle structure. Strains lacking expression of the functional tip protein fail to intoxicate host cells.P. aeruginosa encodes a T3S that is highly homologous to the proteins encoded by Yersinia species. The needle tip proteins of Yersinia, LcrV, and P. aeruginosa, PcrV, share 37% identity and 65% similarity. Other known tip proteins are AcrV (Aeromonas, IpaD (Shigella, SipD (Salmonella, BipD (Burkholderia, EspA (EPEC, EHEC, Bsp22 (Bordetella, with additional proteins identified from various Gram negative species, such as Vibrio and Bordetella. The tip proteins can serve as a protective antigen or may be critical for sensing host cells and evading innate immune responses. Recognition of the host microenvironment transcriptionally activates synthesis of T3SS components. The machinery appears to be mechanically controlled by the assemblage of specific junctions within the apparatus. These junctions include the tip and base of the T3 apparatus, the needle proteins and components within the bacterial cytoplasm. The tip proteins likely have chaperone functions for translocon proteins, allowing the proper assembly of translocation channels in the host membrane and completing vectorial delivery of effector proteins into the host cytoplasm. Multifunctional features of the needle-tip proteins appear to be intricately controlled. In this review, we highlight the functional aspects and complex controls of T3 needle-tip proteins with particular emphasis on PcrV and LcrV.
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In-plane ultrasonic needle tracking using a fiber-optic hydrophone
Energy Technology Data Exchange (ETDEWEB)
Xia, Wenfeng, E-mail: wenfeng.xia@ucl.ac.uk; Desjardins, Adrien E. [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT (United Kingdom); Mari, Jean Martial [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom and GePaSud, University of French Polynesia, Faa’a 98702, French Polynesia (France); West, Simeon J. [Department of Anaesthesia, University College Hospital, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU (United Kingdom); Ginsberg, Yuval; David, Anna L. [Institute for Women’s Health, University College London, 86-96 Chenies Mews, London WC1E 6HX (United Kingdom); Ourselin, Sebastien [Center for Medical Imaging Computing, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2015-10-15
Purpose: Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real-time image guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber-optic ultrasound receiver in conjunction with the imaging probe used to acquire B-mode ultrasound images. Methods: Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber-optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B-mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third. Results: During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal-to-noise (SNR) of the needle tip was found to depend on the insertion angle. With
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Mechanics of needle-tissue interaction
Roesthuis, Roy; van Veen, Youri; Jahya, Alex; Misra, Sarthak
2011-01-01
When a needle is inserted into soft tissue, interac- tion forces are developed at the needle tip and along the needle shaft. The needle tip force is due to cutting of the tissue, and the force along the needle shaft is due to friction between needle and tissue. In this study, the friction force is
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Beigi, Parmida; Rohling, Robert
2014-03-01
Despite the wide range and long history of ultrasound guided needle insertions, an unresolved issue in many cases is clear needle visibility. A well-known ad hoc technique to detect the needle is to move the stylet and look for changes in the needle appearance. We present a new method to automatically locate a moving stylet/catheter within a stationary cannula using motion detection. We then use this information to detect the needle trajectory and the tip. The differences between the current frame and the previous frame are detected and localized, to minimize the influence of tissue global motions. A polynomial fit based on the detected needle axis determines the estimated stylet shaft trajectory, and the extent of the differences along the needle axis represents the tip. Over a few periodic movements of the stylet including its full insertion into the cannula to the tip, a combination of polynomial fits determines the needle trajectory and the last detected point represents the needle tip. Experiments are conducted in water bath and bovine muscle tissue for several stylet/catheter materials. Results show that a plastic stylet has the best needle shaft and tip localization accuracy in the water bath with RMSE = 0:16 mm and RMSE = 0:51 mm, respectively. In the bovine tissue, the needle tip was best localized with the plastic catheter with RMSE = 0:33 mm. The stylet tip localization was most accurate with the steel stylet, with RMSE = 2:81 mm and the shaft was best localized with the plastic catheter, with RMSE = 0:32 mm.
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Fujii, Chieko
2013-01-01
Complications resulting from venipuncture include vein and nerve damage, hematoma, and neuropathic pain. Although the basic procedures are understood, few analyses of actual data exist. It is important to improve the safety standards of this technique during venipuncture. This study aimed to obtain data on actual needle movement during vacuum venipuncture in order to develop appropriate educational procedures. Six experienced nurses were recruited to collect blood samples from 64 subjects. These procedures were recorded using a digital camera. Software was then used to track and analyze motion without the use of a marker in order to maintain the sterility of the needle. Movement along the X- and Y-axes during blood sampling was examined. Approximately 2.5 cm of the needle was inserted into the body, of which 6 mm resulted from advancing or moving the needle following puncture. The mean calculated puncture angle was 15.2°. Given the hazards posed by attaching and removing the blood collection tube, as well as by manipulating the needle to fix its position, the needle became unstable whether it was fixed or not fixed. This study examined venipuncture procedures and showed that the method was influenced by increased needle movement. Focusing on skills for puncturing the skin, inserting the needle into the vein, and changing hands while being conscious of needle-tip stability may be essential for improving the safety of venipuncture.
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Francica, G; Marone, G
1999-05-01
Radiofrequency hyperthermia using the newly-developed 'cooled-tip' needle has recently been proposed as a therapeutic modality for hepatocellular carcinoma (HCC). Herein we report our preliminary results on feasibility and effectiveness of the thermal ablation of mono- or pauci-focal hepatocellular carcinoma with the cooled-tip needle. We treated 15 cirrhotic patients (mean age 68.8 years; 12 males; 14 HCV-positive; 13 in Child's Class A and 2 in Class B) with 20 hepatocellular carcinoma nodules (mean diameter 28.1 mm; range 10-43 mm; nine lesions with diameter greater than 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W of power) connected to a 18 g perfusion electrode needle with an exposed tip of 2-3 cm. The circuit was closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infused a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out in general anesthesia without intubation. Dynamic helical CT was carried out 15-20 days after thermal ablation to assess therapeutic efficacy. In all, 38 areas of coagulation necrosis (at 1000-1200 mA for 10-15 min) were generated in 24 sessions in the 20 hepatocellular carcinoma nodules (mean 1.9 lesions per nodule and 1.2 sessions per nodule). Complete necrosis as assessed at dynamic CT (lack of enhancement during the arteriographic phase) was achieved in 75% of cases in a single session; after a second RF session success rate was 90% (18 out of 20 nodules). A self-limited pleurisy along with a 5-fold increase in transaminases occurred in one patient; a 3-fold elevation of transaminases was encountered in three other patients. During the follow-up (median 15 months) five patients had recurrent hepatocellular carcinoma with a 1-year disease free interval of 64%. Of the
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Sound source location in cavitating tip vortices
International Nuclear Information System (INIS)
Higuchi, H.; Taghavi, R.; Arndt, R.E.A.
1985-01-01
Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress
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Vrooijink, Gustaaf J.; Abayazid, Momen; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak
2015-01-01
Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600
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Directory of Open Access Journals (Sweden)
Fujii C
2013-07-01
Full Text Available Chieko FujiiFaculty of Nursing and Medical Care, Keio University, Kanagawa, JapanBackground: Complications resulting from venipuncture include vein and nerve damage, hematoma, and neuropathic pain. Although the basic procedures are understood, few analyses of actual data exist. It is important to improve the safety standards of this technique during venipuncture. This study aimed to obtain data on actual needle movement during vacuum venipuncture in order to develop appropriate educational procedures.Methods: Six experienced nurses were recruited to collect blood samples from 64 subjects. These procedures were recorded using a digital camera. Software was then used to track and analyze motion without the use of a marker in order to maintain the sterility of the needle. Movement along the X- and Y-axes during blood sampling was examined.Results: Approximately 2.5 cm of the needle was inserted into the body, of which 6 mm resulted from advancing or moving the needle following puncture. The mean calculated puncture angle was 15.2°. Given the hazards posed by attaching and removing the blood collection tube, as well as by manipulating the needle to fix its position, the needle became unstable whether it was fixed or not fixed.Conclusion: This study examined venipuncture procedures and showed that the method was influenced by increased needle movement. Focusing on skills for puncturing the skin, inserting the needle into the vein, and changing hands while being conscious of needle-tip stability may be essential for improving the safety of venipuncture.Keywords: blood collection, nerve damage, motion analysis, patient safety, puncture angle, clinical education
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Iftimia, Nicusor; Park, Jesung; Maguluri, Gopi; Krishnamurthy, Savitri; McWatters, Amanda; Sabir, Sharjeel H
2018-02-01
We report the development and the pre-clinical testing of a new technology based on optical coherence tomography (OCT) for investigating tissue composition at the tip of the core biopsy needle. While ultrasound, computed tomography, and magnetic resonance imaging are routinely used to guide needle placement within a tumor, they still do not provide the resolution needed to investigate tissue cellularity (ratio between viable tumor and benign stroma) at the needle tip prior to taking a biopsy core. High resolution OCT imaging, however, can be used to investigate tissue morphology at the micron scale, and thus to determine if the biopsy core would likely have the expected composition. Therefore, we implemented this capability within a custom-made biopsy gun and evaluated its capability for a correct estimation of tumor tissue cellularity. A pilot study on a rabbit model of soft tissue cancer has shown the capability of this technique to provide correct evaluation of tumor tissue cellularity in over 85% of the cases. These initial results indicate the potential benefit of the OCT-based approach for improving the success of the core biopsy procedures.
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[Treatment of trigger finger with located needle knife].
Zhang, Qi-Feng; Yang, Jiang; Xi, Sheng-Hua
2016-07-25
To investigate the clinical effects of located needle knife in the treatment of trigger finger. The clinical data of 133 patients(145 fingers) with trigger finger underwent treatment with located needle knife from September 2010 to March 2014 were retrospectively analyzed. There were 37 males(40 fingers) and 96 females (105 fingers), aged from 18 to 71 years old with a mean of 51.8 years. Course of disease was from 1 to 19 months with an average of 8.2 months. Affected fingers included 82 thumbs, 12 index fingers, 11 middle fingers, 36 ring fingers, and 4 little fingers. According to the standard of Quinnell grade, 42 fingers were grade III, 92 fingers were grade IV, and 11 fingers were grade V. Firstly the double pipe gab was put into the distal edge of hypertrophic tendon sheath, then small knife needle was used to release the sheath proximally along the tendon line direction. The informations of wound healing and nerve injury, postoperative finger function, finger pain at 6 months were observed. The operation time was from 8 to 25 min with an average of 9.8 min. All the patients were followed up from 6 to 26 months with an average of 12.5 months. No complications such as the wound inflammation and seepage, vascular or nerve injuries were found. According to the standard of Quinnell grade, 123 fingers got excellent results, 15 good, 7 poor. It's a good choice to treat trigger finger with located needle knife in advantage of minimal invasion, simple safe operation, and it should be promoted in clinic.
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Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György
2009-08-01
Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers
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Cavernous sinus lesions biopsy with neuronavigation and tip-cut needle
Lorenzetti, Martin; Carvalho, Herculano; Cattoni, Maria; Gonçalves-Ferreira, Antonio; Pimentel, José; Antuñes, Joao
2014-01-01
Background: Transoval biopsy of cavernous sinus (CS) lesions is the last non-invasive diagnostic option in those 15% of patients in whom etiology remains unclear in spite of extensive neuroradiological imaging, clinical assessment, and laboratory evaluation. However, there are no guidelines defining indications and the most appropriate technique for this procedure. Case Description: We present four patients in whom we performed X-ray and neuronavigation-assisted transoval CS biopsies using tip-cut needles. Conclusion: The technique described allows the operator to determine the optimal angle for entering the CS, avoiding the complications due to distorted anatomy, and facilitating orientation once inside the CS. It reduces both radiation exposure as well as general anesthesia duration. PMID:25593783
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Energy Technology Data Exchange (ETDEWEB)
Thomas, Christoph, E-mail: Christoph.thomas@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Wojtczyk, Hanne [Section of Experimental Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Rempp, Hansjoerg; Clasen, Stephan; Horger, Marius [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Lassberg, Christoph von [Department of Sports Medicine, University of Tuebingen, Silcherstrasse 5, 72076 Tuebingen (Germany); Fritz, Jan [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287 (United States); Claussen, Claus D. [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Pereira, Philippe L. [Department of Radiology, Minimally Invasive Therapies and Nuclearmedicine, SLK-Kliniken Heilbronn GmbH, Am Gesundbrunnen 20-26, 74078 Heilbronn (Germany)
2011-09-15
Objective: To assess the artefact properties of a MR-compatible carbon fibre needle with a nitinol mandrin in vitro and to report first clinical experiences. Materials and methods: In vitro, the carbon fibre/nitinol needle was imaged at different angles against the main magnetic field (1.5 T open bore magnet). A gradient echo MR fluoroscopy sequence (GRE: TR 9.3 ms, TE 3.12 ms, bandwidth 200 Hz/pixel, flip-angle 12{sup o}) and a fast turbo spin echo sequence (FSE: TR 412 ms, TE 9.7 ms, bandwidth 200 Hz/pixel, flip-angle 150{sup o}) were used. Artefact width, needle intensity contrast and needle tip location errors were assessed. In vivo, lumbar periradicular corticosteroid injections and one sclerotherapy were performed with carbon fibre needles (10 procedures) and with titanium alloy needles (2 procedures). The artefact sizes and contrasts were measured. Results: In vitro, artefact diameters of the carbon fibre needle ranged from 3.3 to 4.6 mm, contrasts from 0.11 to 0.52, with larger artefact contrasts and widths with the GRE sequence. Needle tip location errors of -2.1 to -2.8 mm were observed. Decreasing angles to the main field lead to smaller artefacts. In vivo, the carbon fibre/nitinol needle produced smaller artefacts (mean width FSE/GRE: 2.8 mm/4.6 mm) with lower contrast (0.30-0.42) than the titanium alloy needle (mean width FSE/GRE: 4.1 mm/7.5 mm, contrast 0.60-0.73). Conclusions: The carbon fibre/nitinol needle is useful for performing MR-guided interventions at 1.5 T, producing more subtle artefacts than a titanium alloy needle, but with an incomplete depiction and thus inaccurate localization of the needle tip.
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Observations of needle-tissue interactions
Misra, Sarthak; Reed, Kyle B.; Ramesh, K.T.; Okamura, Allison M.
2009-01-01
Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the loads based on the geometry of the bevel edge and gel material
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EUS needle identification comparison and evaluation (NICE) study (with videos)
Tang, Shou-jiang; Vilmann, Andreas S.; Saftoiu, Adrian; Wang, Wanmei; Streba, Costin; Fink, Peter P.; Griswold, Michael; Wu, Ruonan; Dietrich, Christoph F.; Jenssen, Christian; Hocke, Michael; Kantowski, Marcus; Pohl, Jürgen; Fockens, Paul; Annema, Jouke T.; van der Heijden, Erik H.F.M.; Havre, Roald Flesland; Pham, Khanh Do-Cong; Kunda, Rastislav; Deprez, Pierre H.; Mariana, Jinga; Vazquez-Sequeiros, Enrique; Larghi, Alberto; Buscarini, Elisabetta; Fusaroli, Pietro; Lahav, Maor; Puri, Rajesh; Garg, Pramod Kumar; Sharma, Malay; Maluf-Filho, Fauze; Sahai, Anand; Brugge, William R.; Lee, Linda S.; Aslanian, Harry R.; Wang, Andrew Y.; Shami, Vanessa M.; Markowitz, Arnold; Siddiqui, Ali A.; Mishra, Girish; Scheiman, James M.; Isenberg, Gerard; Siddiqui, Uzma D.; Shah, Raj J.; Buxbaum, James; Watson, Rabindra R.; Willingham, Field F.; Bhutani, Manoop S.; Levy, Michael J.; Harris, Cynthia; Wallace, Michael B.; Nolsøe, Christian Pállson; Lorentzen, Torben; Bang, Niels; Sørensen, Sten Mellerup; Gilja, Odd Helge; D’Onofrio, Mirko; Piscaglia, Fabio; Gritzmann, Norbert; Radzina, Maija; Sparchez, Zeno Adrian; Sidhu, Paul S.; Freeman, Simon; McCowan, Timothy C.; de Araujo, Cyrillo Rodrigues; Patel, Akash; del Ali, Mohammad A; Campbell, Garth; Chen, Edward; Vilmann, Peter
2017-01-01
Background and Aims Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) or biopsy is widely practiced. Optimal sonographic visualization of the needle is critical for image guided interventions. There are several commercially available needles but no bench-top testing and direct comparison of these needles to reveal their inherent echogenicity. The aims are to provide bench-top data that can be used to guide clinical applications and to promote future device research and development. Methods Descriptive bench-top testing and comparison. Bench-top testing of 8 commonly used EUS-FNA needles (all of 22 gauge in size): SonoTip Pro Control (Medi-Globe); Expect Slimline (Boston Scientific); EchoTip, EchoTip Ultra, EchoTip ProCore High Definition, (Cook Medical); ClearView (Conmed); EZ Shot2 (Olympus); BNX (Beacon Endoscopic); and 2 new prototype needles that are coated by echogenic polymers by Medi-Globe. Blinded evaluation of standardized and unedited videos by 43 EUS endoscopists and 17 radiologists specialized in gastrointestinal ultrasound examination that is unfamiliar with EUS needle devices. Results There was no significant difference in the ratings and rankings of these needles between endosonographers and radiologists. Overall, one prototype needle was rated as the best, ranking 10% to 40% higher than all other needles (p<0.01). Among the commercially available needles, the EchoTip Ultra needle and the ClearView needle were top choices. The EZ Shot 2 needle was ranked statistically lower than other needles (30%–75% worse, p<0.001). Conclusions All FNA needles have their inherent and different echogenicity, and these differences are similarly recognized by EUS endoscopists and radiologists. Needles with polymeric coating from the entire shaft to the needle tip may offer better echogenicity. PMID:26873530
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Directory of Open Access Journals (Sweden)
William D. Picking
2012-11-01
Full Text Available Förster resonance energy transfer (FRET provides a powerful tool for monitoring intermolecular interactions and a sensitive technique for studying Å-level protein conformational changes. One system that has particularly benefited from the sensitivity and diversity of FRET measurements is the maturation of the Shigella type III secretion apparatus (T3SA needle tip complex. The Shigella T3SA delivers effector proteins into intestinal cells to promote bacterial invasion and spread. The T3SA is comprised of a basal body that spans the bacterial envelope and a needle with an exposed tip complex that matures in response to environmental stimuli. FRET measurements demonstrated bile salt binding by the nascent needle tip protein IpaD and also mapped resulting structural changes which led to the recruitment of the translocator IpaB. At the needle tip IpaB acts as a sensor for host cell contact but prior to secretion, it is stored as a heterodimeric complex with the chaperone IpgC. FRET analyses showed that chaperone binding to IpaB’s N-terminal domain causes a conformational change in the latter. These FRET analyses, with other biophysical methods, have been central to understanding T3SA maturation and will be highlighted, focusing on the details of the FRET measurements and the relevance to this particular system.
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Percutaneous radiofrequency treatment of osteoid osteoma using cool-tip electrodes
Energy Technology Data Exchange (ETDEWEB)
Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain)]. E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain); Ortiz, Eduardo [Departamento de Cirugia ortopedica, Fundacion Hospital Alcorcon, Madrid (Spain)
2005-12-15
Objectives: To report our experience with percutaneous cool-tip radiofrequency ablation of osteoid osteomas and to evaluate clinical outcome. Methods and material: Forty-one patients with clinically and radiologically suspected osteoid osteoma were seen over a 48-month period (27 males and 14 females with a mean age of 18.7 years; range 5-43 years). Thirty-eight patients were treated by computed tomography (CT)-guided percutaneous radiofrequency ablation. The procedure was performed under regional or general anaesthesia. After location of the nidus, a 14G-bone biopsy needle is introduced into the nidus. Sampling is performed with a 17G-bone biopsy needle using a coaxial technique. The radiofrequency needle with a 10 mm active tip (cool-tip) is inserted through the biopsy needle and is connected to the radiofrequency generator for 6-8 min. Results: Primary success was obtained in 37 patients (97%) with a 100% secondary success rate. All patients are currently pain-free. No major complications occurred. Patients could resume unrestricted normal activity within 24 h. Conclusions: Percutaneous radiofrequency ablation of osteoid osteomas is an efficient and safe method that can be considered the procedure of choice for most cases.
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Energy Technology Data Exchange (ETDEWEB)
Moon, Yong Ju; Jeong, Yong Yeon; Kim, Jeong; Yim, Nam yeol; Kang, Heoung Keun [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of); Kim, Eun Ha; Yoon, Kwon Ha [School of Medicine, Wonkwang Univ., Iksan (Korea, Republic of); Ko, Seog Wan [School of Medicine, Chonbuk National Univ., Jeonju (Korea, Republic of)
2004-12-01
The purpose of this study was to compare the shape and volume of the radio-frequency induced lesions produced by two commercially available radio-frequency ablation (RFA) systems, the expandable and cooled-tip needles, in clinical patients and an experimental model. A twelve-array anchor expandable needle electrode and a single cooled-tip needle electrode were used to treat hepatic tumors with a single session in 23 patients (20 hepatocellular carcinomas and 3 hepatic metastases) and fourteen patients (10 hepatocellular carcinomas and 4 hepatic metastases), respectively. Twenty RFA induced lesions were created with each system in 10 explanted bovine livers. The shape of the RFA induced lesions were divided into oval lesions along or perpendicular to the axis of the electrode and spherical lesions, and we then calculated the volumes of the RFA induced lesions. Fourteen (61%) lesions of the 23 patients treated with the expandable system were oval perpendicular to the axis of the electrode and nine (39%) of the lesions were spherical. All the lesions (100%) of the 14 patients treated with the cooled-tip needle were ovaI along the axis of the electrode. In the ex vivo bovine livers, the shape of the all RFA induced lesions was oval perpendicular to the axis of the electrode for the expandable needle, and oval along the axis of the electrode for the cooled-tip needle. The mean diameter and volume of the RFA induced lesions in the patients were 3.35{+-}0.56 cm and 19.9{+-}6.53 cm{sup 3}, respectively, for the expandable needle and 3.58{+-}0.78 cm and 23.19{+-}5.27 cm{sup 3}, respectively, for the cooled-tip needle. In the ex vivo model, the mean diameter and volume of RFA induced lesions were 3.41{+-}0.59 cm and 26.59{+-}8.02 cm{sup 3}, respectively, for the expandable needle, and 4.04{+-}0.65 cm and 33.82{+-}6.16 cm{sup 3}, respectively, for the cooled-tip needle (p <0.05). These results indicate that the shape of RFA induced lesions with the expandable needle were oval
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Directory of Open Access Journals (Sweden)
Rampalli Viswa Chandra
2016-01-01
Full Text Available Context: Electrosurgery offers many unique advantages such as hemostasis and precise tissue cutting; however, there are a number of disadvantages including thermal injury and delayed wound healing. Aims: The aim of the present study was to compare the outcomes of incisions made by Colorado® microdissection needle, electrosurgery tip, and surgical blade during periodontal surgery. Settings and Design: Twenty-two individuals participated in this study. Three quadrants in each individual were randomly assigned into each of the following experimental groups: Colorado® microdissection needle (CMD, electrosurgery tip (EC and surgical blade (BP, in which, incisions were given with Colorado® microdissection needle, straight electrocautery tip, and a scalpel blade, respectively. Materials and Methods: Blood loss (BL was measured immediately after surgery, and changes in interdental papilla dimensions were recorded at baseline, 7, 30, 120, and 180 days after surgery. Measures of periodontal disease were recorded at baseline, 120, and 180 days after surgery. Postoperative pain and wound healing were recorded at 1, 7, and 15 days after surgery. Results: The use of CMD for periodontal surgery showed better results over EC in all parameters. CMD resulted in lesser bleeding and less postoperative pain and attained similar results to that of BP in clinical parameters of periodontal disease. Conclusions: Colorado® microdissection needle may be a better choice for incisions as it seems to show less tissue damage than cautery and offers tissue healing comparable to scalpel blade.
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Energy Technology Data Exchange (ETDEWEB)
Veltri, Andrea, E-mail: andrea.veltri@unito.it; Busso, Marco; Sardo, Diego; Angelino, Valeria; Priola, Adriano M. [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Novello, Silvia [University of Torino, Department of Oncology, San Luigi Gonzaga Hospital (Italy); Barba, Matteo [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Gatti, Gaia; Righi, Luisella [University of Torino, Department of Pathology, San Luigi Gonzaga Hospital (Italy)
2017-06-15
PurposeTo prospectively evaluate feasibility and diagnostic performance of the 14-gauge helical-tip (Spirotome™, Cook{sup ®} Medical, Bloomington, USA) needle in transthoracic needle biopsy (TTNB) of lung lesions, compared to a conventional 18-gauge Tru-Cut needle.Materials and MethodsStudy was institutional review board approved, with informed consent obtained. Data from synchronous Spirotome and Tru-Cut image-guided TTNB of 20 consecutive patients with malignant peripheral lung tumors larger than 3 cm were enrolled for pathologic characterization and mutational analysis. Samples obtained with Spirotome and Tru-Cut needle were compared for fragmentation, length, weight, morphologic and immunohistochemistry typifying, tumor cellularity (TC) and DNA concentration.ResultsThe technical success rate for TTNB with Spirotome was 100%, and no major complications occurred. Less fragmentation (mean 2 vs. 3 fragments, P = .418), greater weight (mean 13 vs. 8.5 mg, P = .027) and lower length (mean 10.2 vs. 12.6 mm, P = .174) were observed with Spirotome compared to Tru-Cut needle. Accuracy of Spirotome and Tru-Cut needle in defining cancer histotype was similar (90%). Absolute and relative TC (mean 42 vs. 38, 124 vs. 108/10HPF), and DNA concentration (mean 49.6 vs. 39.0 ng/μl) were higher with Spirotome compared to Tru-Cut needle, with no statistical significance (P = .787 and P = .140, respectively).Conclusions Percutaneous 14-gauge Spirotome TTNB of selected lesions is feasible and accurate. It provides adequate samples for diagnosis, comparable to 18-gauge Tru-Cut needle, with a higher amount of tumor tissue (weight, TC, DNA concentration) even in shorter samples.
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Torsional Dynamics of Steerable Needles: Modeling and Fluoroscopic Guidance
Swensen, John P.; Lin, MingDe; Okamura, Allison M.; Cowan, Noah J.
2017-01-01
Needle insertions underlie a diversity of medical interventions. Steerable needles provide a means by which to enhance existing needle-based interventions and facilitate new ones. Tip-steerable needles follow a curved path and can be steered by twisting the needle base during insertion, but this twisting excites torsional dynamics that introduce a discrepancy between the base and tip twist angles. Here, we model the torsional dynamics of a flexible rod—such as a tip-steerable needle—during subsurface insertion and develop a new controller based on the model. The torsional model incorporates time-varying mode shapes to capture the changing boundary conditions inherent during insertion. Numerical simulations and physical experiments using two distinct setups—stereo camera feedback in semi-transparent artificial tissue and feedback control with real-time X-ray imaging in optically opaque artificial tissue— demonstrate the need to account for torsional dynamics in control of the needle tip. PMID:24860026
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[Novel echogenic needle for ultrasound-guided peripheral nerve block "Hakko type CCR"].
Takayama, Wataru; Yasumura, Rie; Kaneko, Takehiko; Kobayashi, Yoshiro; Kamada, Takaaki; Yoshikawa, Tamotsu; Aoyama, Yasuhiko
2009-04-01
A novel echogenic insulated nerve block needle (CCR-needle: Echogenic Needle Type CCR; Hakko, Japan) is commercially available since 2006 in Japan. This needle has three echogenic dimples, namely corner cube reflectors (CCR) on its tip. The CCR-needle will potentially provide a significant advantage for detecting the needle tip. In this report, we firstly evaluated this new disposable echogenic needle in simulation phantom, and demonstrated improved visibility of the needle tip. Afterwards, an interscalene brachial plexus block was performed on a male patient undergoing shoulder surgery. The needle insertion procedure was the "out of plane" ultrasound-guided technique using simultaneous electrical nerve stimulation. The surgery was successfully conducted without any complications.
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Enhanced Visualization of Fine Needles Under Sonographic Guidance Using a MEMS Actuator
Directory of Open Access Journals (Sweden)
Zhiyuan Shen
2015-01-01
Full Text Available Localization of a needle tip is important for biopsy examinations in clinics. However, the needle tip is sometimes difficult to discern under the guidance of sonography due to its poor visibility. A mini actuator that radiates a low-intensity ultrasound wave was manufactured using micro-electro-mechanical system (MEMS technology. Interference between the radiated and diagnostic ultrasound pulses was observed as bright lines in the B-mode ultrasound image, from which the mini actuator could be recognized with ease. Because the distance between the mini actuator and the needle tip is fixed, the needle tip can be determined despite its inconsistent appearance in the sonography. Both gel phantom and ex vivo tissue evaluation showed that the needle tip can be determined reliably utilizing the acoustic interference pattern.
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Transbronchial needle aspiration with a new electromagnetically-tracked TBNA needle
Choi, Jae; Popa, Teo; Gruionu, Lucian
2009-02-01
Transbronchial needle aspiration (TBNA) is a common method used to collect tissue for diagnosis of different chest diseases and for staging lung cancer, but the procedure has technical limitations. These limitations are mostly related to the difficulty of accurately placing the biopsy needles into the target mass. Currently, pulmonologists plan TBNA by examining a number of Computed Tomography (CT) scan slices before the operation. Then, they manipulate the bronchoscope down the respiratory track and blindly direct the biopsy. Thus, the biopsy success rate is low. The diagnostic yield of TBNA is approximately 70 percent. To enhance the accuracy of TBNA, we developed a TBNA needle with a tip position that can be electromagnetically tracked. The needle was used to estimate the bronchoscope's tip position and enable the creation of corresponding virtual bronchoscopic images from a preoperative CT scan. The TBNA needle was made with a flexible catheter embedding Wang Transbronchial Histology Needle and a sensor tracked by electromagnetic field generator. We used Aurora system for electromagnetic tracking. We also constructed an image-guided research prototype system incorporating the needle and providing a user-friendly interface to assist the pulmonologist in targeting lesions. To test the feasibility of the accuracy of the newly developed electromagnetically-tracked needle, a phantom study was conducted in the interventional suite at Georgetown University Hospital. Five TBNA simulations with a custom-made phantom with a bronchial tree were performed. The experimental results show that our device has potential to enhance the accuracy of TBNA.
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International Nuclear Information System (INIS)
Peikari, Mohammad; Chen, Thomas Kuriran; Lasso, Anras; Heffter, Tamas; Fichtinger, Gabor; Burdette, Everette C.
2012-01-01
Purpose: Ultrasound elevation beamwidth leads to image artifacts and uncertainties in localizing objects (such as a surgical needle) in ultrasound images. The authors examined the clinical significance of errors caused by elevation beamwidth artifacts and imaging parameters in needle insertion procedures. Methods: Beveled prostate brachytherapy needles were inserted through all holes of a grid template under real-time transrectal ultrasound (TRUS) guidance. The needle tip position as indicated by the TRUS image was compared to their observed physical location. A new device was developed to measure the ultrasound elevation beamwidth. Results: Imaging parameters of the TRUS scanner have direct impact on the localization error ranging from 0.5 up to 4 mm. The smallest localization error was observed laterally close to the center of the grid template and axially within the beam's focal zone. Largest localization error occurs laterally around both sides of the grid template and axially within the beam's far field. The authors also found that the localization errors vary with both lateral and elevation offsets. Conclusions: The authors found properly adjusting the TRUS imaging settings to lower the ultrasound gain and power effectively minimized the appearance of elevation beamwidth artifacts and in turn reduced the localization errors of the needle tip.
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Kalman filter-based EM-optical sensor fusion for needle deflection estimation.
Jiang, Baichuan; Gao, Wenpeng; Kacher, Daniel; Nevo, Erez; Fetics, Barry; Lee, Thomas C; Jayender, Jagadeesan
2018-04-01
In many clinical procedures such as cryoablation that involves needle insertion, accurate placement of the needle's tip at the desired target is the major issue for optimizing the treatment and minimizing damage to the neighboring anatomy. However, due to the interaction force between the needle and tissue, considerable error in intraoperative tracking of the needle tip can be observed as needle deflects. In this paper, measurements data from an optical sensor at the needle base and a magnetic resonance (MR) gradient field-driven electromagnetic (EM) sensor placed 10 cm from the needle tip are used within a model-integrated Kalman filter-based sensor fusion scheme. Bending model-based estimations and EM-based direct estimation are used as the measurement vectors in the Kalman filter, thus establishing an online estimation approach. Static tip bending experiments show that the fusion method can reduce the mean error of the tip position estimation from 29.23 mm of the optical sensor-based approach to 3.15 mm of the fusion-based approach and from 39.96 to 6.90 mm, at the MRI isocenter and the MRI entrance, respectively. This work established a novel sensor fusion scheme that incorporates model information, which enables real-time tracking of needle deflection with MRI compatibility, in a free-hand operating setup.
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Influence of arm movement on central tip location of peripherally inserted central catheters (PICCs)
International Nuclear Information System (INIS)
Connolly, Bairbre; Amaral, Joao; Walsh, Sharon; Temple, Michael; Chait, Peter; Stephens, Derek
2006-01-01
PICCs are increasingly employed in children. Some of their risks relate to the location of the central tip. Despite care when placing lines, they sometimes move. To evaluate the influence of arm movement on the central tip location of PICCs placed in children. The central tip location of PICCs was studied in 85 children, with the arm placed in six positions. The variables of side, vein, site and arm position were examined to measure the direction and range of tip movement. The side, site or vein used did not influence the range of movement of the central tip. Change in position of the arm had a significant influence on the central tip location, moving it an average of 2.2 rib spaces, a maximum of 3.5 ribs. Elbow bending and adduction of the arm caused the central tip to move deeper into the chest, compared to when the arm was straight and abducted 90 . Arm position is the significant variable influencing PICC movement. Side, site and vein do not influence the range of movement significantly. Most PICCs descend deeper into the chest with arm adduction and elbow bending. (orig.)
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International Nuclear Information System (INIS)
Griffin, K. L.; Anderson, O. R.; Tissue, D. T.; Turnbull, M. H.; Whitehead, D.
2004-01-01
An experiment involving comparison of within-leaf variations in cell size, mitochondrial numbers and dark respiration in the most recently expanded tip, the mid-section and the base of needles of Pinus radiata grown for four years at ambient and elevated carbon dioxide partial pressure, is described. Results showed variation in mitochondrial numbers and respiration along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Elevated carbon dioxide pressure caused the number of mitochondria per unit cytoplasm to double regardless of location (tip, basal or mid sections). Under these conditions, greatest mitochondrial density was observed at the tip. The mean size of mitochondria was not affected by either growth at elevated carbon dioxide pressure or by position on the needle. Respiration per unit leaf area at elevated carbon dioxide pressure was highest at the tip of needles, decreasing towards the middle and basal sections. The observed data supports the hypothesis that the highest number of mitochondria per unit area of cytoplasm occurs at the base of the needle, but does not support the hypothesis that the lowest rate of respiration also occurs at the base. It is suggested that the relationship that determines the association between structure and function in these needles is more complex than previously thought. 33 refs., 4 tabs., 1 fig
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Contact assembly of cell-laden hollow microtubes through automated micromanipulator tip locating
International Nuclear Information System (INIS)
Wang, Huaping; Shi, Qing; Guo, Yanan; Li, Yanan; Sun, Tao; Huang, Qiang; Fukuda, Toshio
2017-01-01
This paper presents an automated contact assembly method to fabricate a cell-laden microtube based on accurate locating of the micromanipulator tip. Essential for delivering nutrients in thick engineered tissues, a vessel-mimetic microtube can be precisely assembled through microrobotic contact biomanipulation. The biomanipulation is a technique to spatially order and immobilize cellular targets with high precision. However, due to image occlusion during contact, it is challenging to locate the micromanipulator tip for fully automated assembly. To achieve pixel-wise tracking and locating of the tip in contact, a particle filter algorithm integrated with a determined level set model is employed here. The model ensures precise convergence of the micromanipulator’s contour during occlusion. With the converged active contour, the algorithm is able to pixel-wisely separate the micromanipulator from the low-contrast background and precisely locate the tip with error around 1 pixel (2 µ m at 4 × magnification). As a result, the cell-laden microtube is automatically assembled at six layers/min, which is effective enough to fabricate vessel-mimetic constructs for vascularization in tissue engineering. (paper)
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Meng, Xianggang; Gu, Wenlong; Ma, Fen; Du, Yuzheng; Zhao, Qi
2015-03-01
Acupuncture therapy for regaining consciousness activates soreness, numbness, distention, heaviness, radiating and moving, electric shock and ant climbing sensations at the specific acupoints in the stroke patients. Radiating and moving sensations are the summary of needling sensations such as soreness, numbness and twitching presenting during lifting and thrusting manipulation. These sensations are the essential factors of the therapeutic effect of regaining consciousness. Radiating sensation refers to the conduction along meridians and radiation of soreness and numbness. Moving sensation refers to the local muscular twitching at acupoints and the involuntary movement of limbs, joints and the distal. Acupuncture at the specific acupoints achieves radiating and moving sensations for promoting the circulation in meridians, regulating qi and mind and balancing yin and yang in stroke patients. This therapy was introduced in the paper in view of acupoint location, needle insertion and manipulation.
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C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.
Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J
2010-05-01
Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1
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Driven Around the Bend: Novel Use of a Curved Steerable Needle
Energy Technology Data Exchange (ETDEWEB)
Murphy, Darra T., E-mail: darra.murphy@vch.ca; Korzan, Jeffrey R.; Ouellette, Hugue A.; Liu, David M. [Vancouver General Hospital, Department of Radiology (Canada); Clarkson, Paul W. [Vancouver General Hospital, Department of Orthopedic Surgery (Canada); Munk, Peter L. [Vancouver General Hospital, Department of Radiology (Canada)
2013-04-15
This technical note describes the novel use of a curved, steerable needle to access symptomatic osseous lesions in the pelvis and sacrum for palliative percutaneous treatment that would otherwise be difficult to treat using conventional straight needles. Seven patients with lytic bone lesions were treated. One patient had multiple myeloma; the remaining had metastatic disease: breast carcinoma (n = 2), colorectal carcinoma (n = 1), renal cell carcinoma (n = 1), squamous cell carcinoma (n = 1), and leiomyosarcoma (n = 1). Five of the seven patients had lesions in the posterior acetabulum, and the two other patients had lesions in the sacrum. Four of the seven patients received radiofrequency ablation followed by cementoplasty; three patients received cementation alone. We used a novel needle designed for vertebroplasty, which has an articulating tip allowing it to be guided into lytic bone lesions located in difficult-to-access regions of the pelvis and sacrum. All patients were successfully treated with cementoplasty either with or without thermal ablation. No serious adverse events were reported. The needle was difficult to withdraw in two patients. Steerable curved needles can be successfully used to treat lytic osseous metastases with cementoplasty when lesions are located in sites that may be difficult to reach using conventional straight needles.
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... the portal system using a TIPS needle (a special long needle extending from the neck into the ... Encephalopathy can be treated with certain medications, a special diet or, by revising the stent, but sometimes ...
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Study on design and cutting parameters of rotating needles for core biopsy.
Giovannini, Marco; Ren, Huaqing; Cao, Jian; Ehmann, Kornel
2018-06-15
Core needle biopsies are widely adopted medical procedures that consist in the removal of biological tissue to better identify a lesion or an abnormality observed through a physical exam or a radiology scan. These procedures can provide significantly more information than most medical tests and they are usually performed on bone lesions, breast masses, lymph nodes and the prostate. The quality of the samples mainly depends on the forces exerted by the needle during the cutting process. The reduction of these forces is critical to extract high-quality tissue samples. The most critical factors that affect the cutting forces are the geometry of the needle tip and its motion while it is penetrating the tissue. However, optimal needle tip configurations and cutting parameters are not well established for rotating insertions. In this paper, the geometry and cutting forces of hollow needles are investigated. The fundamental goal of this study is to provide a series of guidelines for clinicians and surgeons to properly select the optimal tip geometries and speeds. Analytical models related to the cutting angles of several needle tip designs are presented and compared. Several needle tip geometries were manufactured from a 14-gauge cannula, commonly adopted during breast biopsies. The needles were then tested at different speeds and on different phantom tissues. According to these experimental measurements recommendations were formulated for rotating needle insertions. The findings of this study can be applied and extended to several biopsy procedures in which a cannula is used to extract tissue samples. Copyright © 2018 Elsevier Ltd. All rights reserved.
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CT-guided spinal injection: initial experience with Sprotte tip needles
Energy Technology Data Exchange (ETDEWEB)
Pua, Uei [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore)
2010-09-15
The purpose of this paper is to describe our initial experience and to illustrate the potential benefits of using small caliber (25 and 27 G), noncutting pencil point needles (Sprotte) with single puncture coaxial technique in CT-guided spinal intervention (CTSI). From January 2009 to June 2009, Sprotte needles with single puncture coaxial technique were used in a total of ten patients for selective nerve root block (SNRB), facet joint block, and pars block under CT fluoroscopy (total of 16 target structures). All procedures were performed without conscious sedation, and visual analog scale (VAS) scores were recorded to determine pain related to needle placement. Total CT fluoroscopy time and out-of-plane needle deviation were obtained. Final needle position was documented by contrast injection for SNRBs and image capture for joint space cannulation. Sixteen out of the 16 structures were successfully targeted. No increase in VAS scores associated with needle placement was recorded, after infiltration of local anesthesia. Optimal peri-neurograms were obtained in all cases of SNRB, despite the side-hole opening in the Sprotte needles. Mean CT fluoroscopy time was 2 s (range 2-8 s per structure), and there was no case of out-of-plane needle deviation that required adjustment of the CT gantry. The use of small caliber Sprotte needles in CTSI is technically feasible and represents a potential refinement to current techniques in the management of chronic spinal pain. (orig.)
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Influence of needle position on lumbar segmental nerve root block selectivity.
Wolff, André P; Groen, Gerbrand J; Wilder-Smith, Oliver H
2006-01-01
In patients with chronic low back pain radiating to the leg, segmental nerve root blocks (SNRBs) are performed to predict surgical outcome and identify the putative symptomatic spinal nerve. Epidural spread may lead to false interpretation, affecting clinical decision making. Systematic fluoroscopic analysis of epidural local anesthetic spread and its relationship to needle tip location has not been published to date. Study aims include assessment of epidural local anesthetic spread and its relationship to needle position during fluoroscopy-assisted blocks. Patients scheduled for L4, L5, and S1 blocks were included in this prospective observational study. Under fluoroscopy and electrostimulation, they received 0.5 mL of a mixture containing lidocaine 5 mg and iohexol 75 mg. X-rays with needle tip and contrast were scored for no epidural spread (grade 0), local spread epidurally (grade 1), or to adjacent nerve roots (grade 2). Sixty-five patients were analyzed for epidural spread, 62 for needle position. Grade 1 epidural spread occurred in 47% of L4 and 28% of L5 blocks and grade 2 spread in 3 blocks (5%; L5 n = 1, S1 n = 2). For lumbar blocks, the needle was most frequently found in the lateral upper half of the intervertebral foramen. Epidural spread occurred more frequently with medial needle positions (P = .06). The findings suggest (P = .06) that the risk of grade 1 and 2 lumbar epidural spread, which results in decreased SNRB selectivity, is greater with medial needle positions in the intervertebral foramen. The variability in anatomic position of the dorsal root ganglion necessitates electrostimulation to guide SNRB in addition to fluoroscopy.
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Roehrich, A Dorothea; Guillossou, Enora; Blocker, Ariel J; Martinez-Argudo, Isabel
2013-02-01
Type III secretion systems (T3SSs) are protein injection devices essential for the interaction of many Gram-negative bacteria with eukaryotic cells. While Shigella assembles its T3SS when the environmental conditions are appropriate for invasion, secretion is only activated after physical contact with a host cell. First, the translocators are secreted to form a pore in the host cell membrane, followed by effectors which manipulate the host cell. Secretion activation is tightly controlled by conserved T3SS components: the needle tip proteins IpaD and IpaB, the needle itself and the intracellular gatekeeper protein MxiC. To further characterize the role of IpaD during activation, we combined random mutagenesis with a genetic screen to identify ipaD mutant strains unable to respond to host cell contact. Class II mutants have an overall defect in secretion induction. They map to IpaD's C-terminal helix and likely affect activation signal generation or transmission. The Class I mutant secretes translocators prematurely and is specifically defective in IpaD secretion upon activation. A phenotypically equivalent mutant was found in mxiC. We show that IpaD and MxiC act in the same intracellular pathway. In summary, we demonstrate that IpaD has a dual role and acts at two distinct locations during secretion activation. © 2013 Blackwell Publishing Ltd.
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[Percutaneous needle aponeurotomy for Dupuytren's disease].
Spies, C K; Müller, L P; Skouras, E; Bassemir, D; Hahn, P; Unglaub, F
2016-02-01
Percutaneous transverse aponeurotomy of the cord by using a hypodermic needle as a scalpel blade in order to improve function of the hand. Symptomatic flexion contracture with positive table top test caused by a single, palpable cord within the palm (primarily Tubiana stages I and II). Multiple, infiltrating or broad-based cords within the palm; irritated skin conditions; exclusive digital cord localization; recurrence after aponeurectomy; previous surgical intervention at the site of interest, digital nerve lesions; lack of patient compliance. Pinpoint surface anesthesia is obtained by injecting each portal area subdermally with 0.1 ml of local anesthetic. These applications start from distally to proximally within the palm while the most distal injection site is located proximal to the distal palm crease. Then the needle tip is introduced perpendicular to the cord. Sawing movements through the cord are performed transversely. While passively extending the contracted finger, the cord is held under tension which guarantees safe cutting. Patients are encouraged to report immediate pain sensation or numbness in order to prevent injuries to neurovascular structures and active finger flexion excludes tendon lesions during the procedure. Introducing the needle tip may be performed at several sites along the cord, if necessary, from distal to proximal at least 5 mm apart with prior pinpoint surface anesthesia. Finally, cautious passive stretching may be done after each release. Bandaging allowing immediate motion; application of a hand-based extension splint-glove during the night for 3-6 months. Recurrence rate was 53% in 15 retrospectively examined patients after a mean interval of 40 months postoperatively.
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Modified microdissection electrocautery needle
Singh, Virendra; Kumar, Pramod
2014-01-01
Electrocautery is routinely used in surgical procedures. The commercially available microdissection electrocautery needles are costly. To overcome this disadvantage, we have modified monopolar electrocautery tip to function as well as commercially available systems.
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Single amino acid substitutions on the needle tip protein IpaD increased Shigella virulence.
Meghraoui, Alaeddine; Schiavolin, Lionel; Allaoui, Abdelmounaaïm
2014-07-01
Infection of colonic epithelial cells by Shigella is associated with the type III secretion system, which serves as a molecular syringe to inject effectors into host cells. This system includes an extracellular needle used as a conduit for secreted proteins. Two of these proteins, IpaB and IpaD, dock at the needle tip to control secretion and are also involved in the insertion of a translocation pore into host cell membrane allowing effector delivery. To better understand the function of IpaD, we substituted thirteen residues conserved among homologous proteins in other bacterial species. Generated variants were tested for their ability to surface expose IpaB and IpaD, to control secretion, to insert the translocation pore, and to invade host cells. In addition to a first group of seven ipaD variants that behaved similarly to the wild-type strain, we identified a second group with mutations V314D and I319D that deregulated secretion of all effectors, but remained fully invasive. Moreover, we identified a third group with mutations Y153A, T161D, Q165L and Y276A, that exhibited increased levels of translocators secretion, pore formation, and cell entry. Altogether, our results offer a better understanding of the role of IpaD in the control of Shigella virulence. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
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Stone, Nelson N; Mouraviev, Vladimir; Schechter, David; Lucia, M Scott; Smith, Elizabeth E; Arangua, Paul; Hoenemeyer, John; Rosa, Jim; Bawa, Rajan; Crawford, E David
2017-09-01
To increase the likelihood of detecting anterior cancers within the prostate and provide a specimen that spans the length of the gland. Newly designed 17- and 15-gauge (G) biopsy needles, a variable actuator, and an integrated pathology system intended for the longer cores were developed and tested for this purpose. Testing was performed comparing 2 common cannula tip grinds, a Vet-point (sharp tip) and a Menghini-point (atraumatic tip), and were tested against 18-G Bard Monopty in porcine kidney. A variable actuator was developed to fire the needle 20-60 mm and tested in cadaver prostates. The aggregate firings for 3 different shot lengths comparing the Vet- with the Menghini-tip cannulas demonstrated 91% vs 85.2% fill (length of specimen/length of core bed, P = .007). A 15-G trocar needle with the Vet-tip cannula also had the best performance, with an aggregate standard deviation of 6.4% across 3 firing ranges and a minimum to maximum specimen length of 81%-105% of potential fill. Cadaver testing with the Vet-tip needles in the actuator for the transrectal (17-G) and transperineal (15-G) biopsies demonstrated mean fills of 93.3% and 76.5%, respectively. The new transrectal ultrasound needle obtained a 2-fold increase in specimen length over the standard Bard device (P actuator, the physician can obtain specimens that include peripheral and anterior zone tissue in 1 core. Determination of cancer location on the longer specimens could enhance focal therapy planning. Copyright © 2017 Elsevier Inc. All rights reserved.
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Precision grid and hand motion for accurate needle insertion in brachytherapy
International Nuclear Information System (INIS)
McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J.
2011-01-01
Purpose: In prostate brachytherapy, a grid is used to guide a needle tip toward a preplanned location within the tissue. During insertion, the needle deflects en route resulting in target misplacement. In this paper, 18-gauge needle insertion experiments into phantom were performed to test effects of three parameters, which include the clearance between the grid hole and needle, the thickness of the grid, and the needle insertion speed. Measurement apparatus that consisted of two datum surfaces and digital depth gauge was developed to quantify needle deflections. Methods: The gauge repeatability and reproducibility (GR and R) test was performed on the measurement apparatus, and it proved to be capable of measuring a 2 mm tolerance from the target. Replicated experiments were performed on a 2 3 factorial design (three parameters at two levels) and analysis included averages and standard deviation along with an analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: Results showed that grid with tight clearance hole and slow needle speed increased precision and accuracy of needle insertion. The tight grid was vital to enhance precision and accuracy of needle insertion for both slow and fast insertion speed; additionally, at slow speed the tight, thick grid improved needle precision and accuracy. Conclusions: In summary, the tight grid is important, regardless of speed. The grid design, which shows the capability to reduce the needle deflection in brachytherapy procedures, can potentially be implemented in the brachytherapy procedure.
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Energy Technology Data Exchange (ETDEWEB)
Kim, Jin Woong; Shin, Sang Soo [Chonnam National University Hospital, Chonnam National University Medical School, Gwangju(Korea, Republic of)
2017-04-15
Ultrasound-guided percutaneous core needle biopsy (USPCB) is used extensively in daily clinical practice for the pathologic confirmation of both focal and diffuse diseases of the abdominal viscera. As a guidance tool, US has a number of clear advantages over computerized tomography or magnetic resonance imaging: fewer false-negative biopsies, lack of ionizing radiation, portability, relatively short procedure time, real-time intra-procedural visualization of the biopsy needle, ability to guide the procedure in almost any anatomic plane, and relatively lower cost. Notably, USPCB is widely used to retrieve tissue specimens in cases of hepatic lesions. However, general radiologists, particularly beginners, find USPCB difficult to perform in abdominal organs other than the liver; indeed, a full understanding of the entire USPCB process and specific considerations for specific abdominal organs is necessary to safely obtain adequate specimens. In this review, we discuss some points and techniques that need to be borne in mind to increase the chances of successful USPCB. We believe that the tips and considerations presented in this review will help radiologists perform USPCB to successfully retrieve target tissue from different organs with minimal complications.
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International Nuclear Information System (INIS)
Kim, Jin Woong; Shin, Sang Soo
2017-01-01
Ultrasound-guided percutaneous core needle biopsy (USPCB) is used extensively in daily clinical practice for the pathologic confirmation of both focal and diffuse diseases of the abdominal viscera. As a guidance tool, US has a number of clear advantages over computerized tomography or magnetic resonance imaging: fewer false-negative biopsies, lack of ionizing radiation, portability, relatively short procedure time, real-time intra-procedural visualization of the biopsy needle, ability to guide the procedure in almost any anatomic plane, and relatively lower cost. Notably, USPCB is widely used to retrieve tissue specimens in cases of hepatic lesions. However, general radiologists, particularly beginners, find USPCB difficult to perform in abdominal organs other than the liver; indeed, a full understanding of the entire USPCB process and specific considerations for specific abdominal organs is necessary to safely obtain adequate specimens. In this review, we discuss some points and techniques that need to be borne in mind to increase the chances of successful USPCB. We believe that the tips and considerations presented in this review will help radiologists perform USPCB to successfully retrieve target tissue from different organs with minimal complications
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Koontz, Nicholas A; Wiggins, Richard H; Stoddard, Gregory J; Shah, Lubdha M
2017-10-01
There is a paucity of evidence-based literature regarding the advantages and disadvantages of the interlaminar approach and needle bevel orientation for performing a lumbar interlaminar epidural steroid injection (ESI). The purpose of this study was to determine if superior versus inferior lamina approach, needle bevel tip orientation, or both may predispose to inadvertent nonepidural penetration during lumbar interlaminar ESI. A prospective study was performed of patients with low back pain with or without radicular pain or neurogenic claudication referred for lumbar interlaminar ESI. Two hundred eleven patients were randomized by interlaminar approach (superior vs inferior) and bevel tip orientation (cranial vs caudal). Lumbar interlaminar ESI was performed by six interventionalists of varying levels of experience using fluoroscopic guidance with curved tip epidural needles, using loss-of-resistance technique and confirmation with contrast opacification. Exact Poisson regression was used to model the study outcome. Two hundred twenty-one lumbar interlaminar ESIs were performed on 211 patients, randomized to a superior (n = 121) or inferior lamina approach (n = 100) and to a cranial (n = 103) or caudal (n = 118) orientation of the bevel tip. Epidural needle placement was confirmed in 96.4% (n = 213) of cases. Nonepidural needle placement was most commonly associated with superior lamina approach and caudal bevel tip orientation, which was marginally significant (adjusted risk ratio, 6.88; 95% CI, 0.93-∞; p = 0.059). Inadvertent nonepidural needle penetration during fluoroscopically guided lumbar interlaminar ESI appears to be affected by approach, with superior lamina approach and caudal bevel tip orientation being the least favorable technique.
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In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle
Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun
2016-06-01
Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment.
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International Nuclear Information System (INIS)
Kuang Yuanwen; Wen Dazhi; Zhou Guoyi; Liu Shizhong
2007-01-01
Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants
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Energy Technology Data Exchange (ETDEWEB)
Kuang Yuanwen [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: kuangyw@scbg.ac.cn; Wen Dazhi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: dzwen@scbg.ac.cn; Zhou Guoyi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: gyzhou@scbg.ac.cn; Liu Shizhong [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: lsz@scbg.ac.cn
2007-01-15
Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants.
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Energy Technology Data Exchange (ETDEWEB)
Kuang Yuanwen [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: kuangyw@scbg.ac.cn; Wen Dazhi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: dzwen@scbg.ac.cn; Zhou Guoyi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: gyzhou@scbg.ac.cn; Liu Shizhong [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: lsz@scbg.ac.cn
2007-02-15
Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants.
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International Nuclear Information System (INIS)
Kuang Yuanwen; Wen Dazhi; Zhou Guoyi; Liu Shizhong
2007-01-01
Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants
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EUS Needle Identification Comparison and Evaluation study (with videos)
DEFF Research Database (Denmark)
Tang, Shou-Jiang; Vilmann, Andreas S; Saftoiu, Adrian
2016-01-01
Control (Medi-Globe); Expect Slimline (Boston Scientific); EchoTip, EchoTip Ultra, EchoTip ProCore High Definition (Cook Medical); ClearView (Conmed); EZ Shot 2 (Olympus); and BNX (Beacon Endoscopic), and 2 new prototype needles, SonoCoat (Medi-Globe), coated by echogenic polymers made by Encapson...
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Fabrication of tungsten wire needles
International Nuclear Information System (INIS)
Roder, A.
1983-02-01
Fine point needles for field emissoin are conventionally produced by electrolytically or chemically etching tungsten wire. Points formed in this manner have a typical tip radius of about 0.5 microns and a cone angle of some 30 degrees. The construction of needle matrix detector chambers has created a need for tungsten needles whose specifications are: 20 mil tungsten wire, 1.5 inch total length, 3 mm-long taper (resulting in a cone angle of about 5 degrees), and 25 micron-radius point (similar to that found on sewing needles). In the process described here for producing such needles, tungsten wire, immersed in a NaOH solution and in the presence of an electrode, is connected first to an ac voltage and then to a dc supply, to form a taper and a point on the end of the wire immersed in the solution. The process parameters described here are for needles that will meet the above specifications. Possible variations will be discussed under each approprite heading
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Force-Sensor-Based Estimation of Needle Tip Deflection in Brachytherapy
Directory of Open Access Journals (Sweden)
Thomas Lehmann
2013-01-01
in real time during needle insertion is the main contribution of this paper. The proposed approach solely relies on the measured forces and torques without a need for any other invasive/noninvasive sensing devices. A few mechanical models have been introduced previously regarding the way the forces are composed along the needle during insertion; we will compare our model to those approaches in terms of accuracy. In order to conduct experiments to verify the deflection model, a custom-built, 2-DOF robotic system for needle insertion is developed and discussed. This system is a prototype of an intelligent, hand-held surgical assistant tool that incorporates the virtual sensor proposed in this paper.
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Spinal anaesthesia in young patients: evaluation of needle gauge ...
African Journals Online (AJOL)
Background:The well-known complication of spinal anaesthesia, postdural puncture headache (PDPH), is especially troublesome in young patients. The needle gauge and configuration of needle tip appear to be the important factors in reducing the incidence of PDPH; however it may increase the incidence of technical ...
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Root canal debris removal using different irrigating needles: An SEM study
Directory of Open Access Journals (Sweden)
Sheetal Ghivari
2011-01-01
Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by
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MLESAC Based Localization of Needle Insertion Using 2D Ultrasound Images
Xu, Fei; Gao, Dedong; Wang, Shan; Zhanwen, A.
2018-04-01
In the 2D ultrasound image of ultrasound-guided percutaneous needle insertions, it is difficult to determine the positions of needle axis and tip because of the existence of artifacts and other noises. In this work the speckle is regarded as the noise of an ultrasound image, and a novel algorithm is presented to detect the needle in a 2D ultrasound image. Firstly, the wavelet soft thresholding technique based on BayesShrink rule is used to denoise the speckle of ultrasound image. Secondly, we add Otsu’s thresholding method and morphologic operations to pre-process the ultrasound image. Finally, the localization of the needle is identified and positioned in the 2D ultrasound image based on the maximum likelihood estimation sample consensus (MLESAC) algorithm. The experimental results show that it is valid for estimating the position of needle axis and tip in the ultrasound images with the proposed algorithm. The research work is hopeful to be used in the path planning and robot-assisted needle insertion procedures.
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International Nuclear Information System (INIS)
Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A; Denis de Senneville, B; Hautvast, G; Binnekamp, D
2016-01-01
Purpose: To develop a new method which adaptively determines the optimal needle insertion sequence for HDR prostate brachytherapy involving divergent needle-by-needle dose delivery by e.g. a robotic device. A needle insertion sequence is calculated at the beginning of the intervention and updated after each needle insertion with feedback on needle positioning errors. Methods: Needle positioning errors and anatomy changes may occur during HDR brachytherapy which can lead to errors in the delivered dose. A novel strategy was developed to calculate and update the needle sequence and the dose plan after each needle insertion with feedback on needle positioning errors. The dose plan optimization was performed by numerical simulations. The proposed needle sequence determination optimizes the final dose distribution based on the dose coverage impact of each needle. This impact is predicted stochastically by needle insertion simulations. HDR procedures were simulated with varying number of needle insertions (4 to 12) using 11 patient MR data-sets with PTV, prostate, urethra, bladder and rectum delineated. Needle positioning errors were modeled by random normally distributed angulation errors (standard deviation of 3 mm at the needle’s tip). The final dose parameters were compared in the situations where the needle with the largest vs. the smallest dose coverage impact was selected at each insertion. Results: Over all scenarios, the percentage of clinically acceptable final dose distribution improved when the needle selected had the largest dose coverage impact (91%) compared to the smallest (88%). The differences were larger for few (4 to 6) needle insertions (maximum difference scenario: 79% vs. 60%). The computation time of the needle sequence optimization was below 60s. Conclusion: A new adaptive needle sequence determination for HDR prostate brachytherapy was developed. Coupled to adaptive planning, the selection of the needle with the largest dose coverage impact
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Development of a high frequency single-element ultrasound needle transducer for anesthesia delivery
Ameri, Golafsoun; Son, Jungik; Liang, Jingwei; Foster, F. Stuart; Ganapathy, Sugantha; Peters, Terry M.
2017-03-01
Epidural anesthesia is one of the most commonly used and yet challenging techniques employed for pain management and anesthesia delivery. The major complications of this procedure are due to accidental dural puncture, with an incidence of 1-3%, which could lead to both temporary and irreversible permanent neurological complications. Needle placement under ultrasound (US) guidance has received increasing interest for improving needle placement accuracy. However, poor needle visibility in US, difficulties in displaying relevant anatomical structure such as dura mater due to attenuation and bone shadowing, and image interpretation variability among users pose significant hurdles for any US guidance system. As a result, US guidance for epidural injections has not been widely adopted for everyday use for the performance of neuraxial blocks. The difficulties in localizing the ligamentum flavum and dura with respect to the needle tip can be addressed by integrating A-mode US, provided by a single-element transducer at the needle tip, into the B-mode US guidance system. We have taken the first steps towards providing such a guidance system. Our goal is to improve the safety of this procedure with minimal changes to the clinical workflow. This work presents the design and development of a 20 MHz single-element US transducer housed at the tip of a 19 G needle hypodermic tube, which can fit inside an epidural introducer needle. In addition, the results from initial transducer characterization tests and performance evaluation of the transducer in a euthanized porcine model are provided.
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... deeply you are sedated. When the needle is advanced through the liver and the pathway is expanded ... are the limitations of TIPS? Patients with more advanced liver disease are at greater risk for worsening ...
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International Nuclear Information System (INIS)
Khan, M. Fawad; Maataoui, Adel; Gurung, Jessen; Schiemann, Mirko; Vogl, Thomas J.; Dogan, Selami; Ackermann, Hanns; Wesarg, Stefan; Sakas, Georgios
2005-01-01
The aim of this work was to determine the accuracy of a new navigational system, Medarpa, with a transparent display superimposing computed tomography (CT) reality on the site of intervention. Medarpa uses an optical and an electromagnetic tracking system which allows tracking of instruments, the radiologist and the transparent display. The display superimposes a CT view of a phantom chest on a phantom chest model, in real time. In group A, needle positioning was performed using the Medarpa system. Three targets (diameter 1.5 mm) located inside the phantom were punctured. In group B, the same targets were used to perform standard CT-guided puncturing using the single-slice technique. The same needles were used in both groups (15 G, 15 cm). A total of 42 punctures were performed in each group. Post puncture, CT scans were made to verify needle tip positions. The mean deviation from the needle tip to the targets was 6.65±1.61 mm for group A (range 3.54-9.51 mm) and 7.05±1.33 mm for group B (range 4.10-9.45 mm). No significant difference was found between group A and group B for any target (p>0.05). No significant difference was found between the targets of the same group (p>0.05). The accuracy in needle puncturing using the augmented reality system, Medarpa, matches the accuracy achieved by CT-guided puncturing technique. (orig.)
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Smart surgical needle actuated by shape memory alloys for percutaneous procedures
Konh, Bardia
feasibility of providing actuation forces using both SMAs and SMPs for the surgical needle was demonstrated in this study. The needle insertion simulation was validated while observing less than 10% deviation between the estimated amount of needle deflection by the simulation and by the experiments. Using this model the effect of needle diameter and its bevel tip angle on the final shape of the needle was investigated. Conclusion: The numerical and experimental studies of this work showed that a highly maneuverable active needle can be made using the actuation of multiple SMA wires in series. To maneuver around the anatomical obstacles of the human body and reach the target location, thin sharp needles are recommended as they would create a smaller radius of curvature. The insertion model presented in this work is intended to be used as a base structure for path planning and training purposes for future studies. (Abstract shortened by UMI.).
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Energy Technology Data Exchange (ETDEWEB)
Prosch, Helmut; Oschatz, Elisabeth; Eisenhuber, Edith; Wohlschlager, Helmut [Otto Wagner Hospital, Department of Radiology, Sanatoriumsstrasse 2, 1140 Vienna (Austria); Mostbeck, Gerhard H., E-mail: gerhard.mostbeck@wienkav.at [Otto Wagner Hospital, Department of Radiology, Sanatoriumsstrasse 2, 1140 Vienna (Austria)
2011-01-15
Purpose: Small subpleural pulmonary lesions are difficult to biopsy. While the direct, short needle path has been reported to have a lower rate of pneumothorax, the indirect path provides a higher diagnostic yield. Therefore, we tried to optimize the needle pathway and minimize the iatrogenic pneumothorax risk by evaluating a CT fluoroscopy guided direct approach to biopsy subpleural lesions. Material and methods: Between 01/2005 and 01/2007, CT fluoroscopy guided core biopsies were performed in 24 patients. Using our technique, the tip of the guide needle remains outside the visceral pleura (17 G coaxial guide needle, 18 G Biopsy-gun, 15 or 22 mm needle path). The position of the lesion relative to the needle tip can be optimized using CT fluoroscopy by adjusting the breathing position of the patient. The Biopty gun is fired with the needle tip still outside the pleural space. Cytological smears are analyzed by a cytopathologist on-site, and biopsies are repeated as indicated with the coaxial needle still outside the pleura. Results: Median nodule size was 1.6 cm (0.7-2.3 cm). A definitive diagnosis was obtained in 22 patients by histology and/or cytology. In one patient, only necrotic material could be obtained. In another patient, the intervention had to be aborted as the dyspnoic patient could not follow breathing instructions. An asymptomatic pneumothorax was present in seven patients; chest tube placement was not required. Conclusion: The presented biopsy approach has a high diagnostic yield and is especially advantageous for biopsies of small subpleural lesions in the lower lobes.
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Energy Technology Data Exchange (ETDEWEB)
Langen, H.J. [Roentgenabteilung der Missionsaerztlichen Klinik Wuerzburg (Germany); Stuetzer, H. [Inst. fuer Medizinische Statistik, Informatik und Epidemiologie der Univ. zu Koeln (Germany); Kugel, H.; Krug, B.; Hesselmann, V.; Schulte, O.; Walter, C.; Landwehr, P. [Inst. und Poliklinik fuer Radiologische Diagnostik der Univ. zu Koeln (Germany)
2000-11-01
To estimate the accuracy of the determination of tip position of MR compatible biopsy needles based on signal voids and artifacts in MR guided biopsies. Method: In a nylon grid phantom an MR compatible 18G needle (E-Z-EM) was measured in a 1.0 T imager using TSE- and FFE-sequences of 20 s and 40 s duration in 34 different orientations of needle versus B{sub 0}, frequency and slice selection gradient. 4 radiologists with no experience in the evaluation of signal void artifacts estimated the needle tip positions from needle tip artifacts. The readers determined the needle tip before and after a 15 minute training session based on high resolution images with explanation of size and shape of specific artifacts of biopsy needles in 12 different orthogonal or parallel orientations to B{sub 0} and frequency encoding gradient that are possible if the needle lies parallel to the slice, i.e. orthogonal to the slice selection gradient. The values obtained before and after the training session were compared to the real position of the needle tip. Results: Mean distance of actual needle tip and tip position as determined from images was 1.8{+-}2.3 mm in TSE- versus 2.5{+-}1.2 mm in FFE-images, with the needle length overestimated. After a 15 minute training session the positioning error decreased significantly to 0.2{+-}1.8 mm for TSE-sequences and to 1.0{+-}1.8 mm for FFE-sequences. A higher accuracy of tip localization was obtained with TSE sequences. Conclusion: In MR guided biopsies using FFE- and TSE-sequences the needle position can be more accurately determined if the reader is familiar with the 12 orthogonal or parallel positions of the needle with respect to B{sub 0} and frequency encoding gradient and the corresponding artifacts. (orig.) [German] Abschaetzung der Praezision, mit der die Spitze einer MR-kompatiblen Biopsienadel anhand ihrer Artefakte bestimmt werden kann. Methode: Experimentell wurde eine MR-kompatible 18 G Biopsienadel (E-Z-EM) in einem 1,0 Tesla MR
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Præstmark, Kezia A; Jensen, Morten L; Madsen, Nils B; Kildegaard, Jonas; Stallknecht, Bente M
2016-01-01
Pen needles used for subcutaneous injections have gradually become shorter, thinner and more thin walled, and thereby less robust to patient reuse. Thus, different needle sizes, alternative tip designs and needles resembling reuse were tested to explore how needle design influences ease of insertion, pain and skin trauma. 30 subjects with injection-treated type 2 diabetes and body mass index 25-35 kg/m 2 were included in the single-blinded study. Each subject received abdominal insertions with 18 different types of needles. All needles were tested twice per subject and in random order. Penetration force (PF) through the skin, pain perception on 100 mm visual analog scale, and change in skin blood perfusion (SBP) were quantified after the insertions. Needle diameter was positively related to PF and SBP (ptrend relation. Lack of needle lubrication and small 'needle hooks' increased PF and SBP (pskin and in polyurethane rubber were linearly related, and pain outcome was dependent of SBP increase. The shape and design of a needle and the needle tip affect ease of insertion, pain and skin trauma. Relations are seen across different data acquisition methods and across species, enabling needle performance testing outside of clinical trials. NCT02531776; results.
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Brachytherapy needle deflection evaluation and correction
International Nuclear Information System (INIS)
Wan Gang; Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron
2005-01-01
In prostate brachytherapy, an 18-gauge needle is used to implant radioactive seeds. This thin needle can be deflected from the preplanned trajectory in the prostate, potentially resulting in a suboptimum dose pattern and at times requiring repeated needle insertion to achieve optimal dosimetry. In this paper, we report on the evaluation of brachytherapy needle deflection and bending in test phantoms and two approaches to overcome the problem. First we tested the relationship between needle deflection and insertion depth as well as whether needle bending occurred. Targeting accuracy was tested by inserting a brachytherapy needle to target 16 points in chicken tissue phantoms. By implanting dummy seeds into chicken tissue phantoms under 3D ultrasound guidance, the overall accuracy of seed implantation was determined. We evaluated methods to overcome brachytherapy needle deflection with three different insertion methods: constant orientation, constant rotation, and orientation reversal at half of the insertion depth. Our results showed that needle deflection is linear with needle insertion depth, and that no noticeable bending occurs with needle insertion into the tissue and agar phantoms. A 3D principal component analysis was performed to obtain the population distribution of needle tip and seed position relative to the target positions. Our results showed that with the constant orientation insertion method, the mean needle targeting error was 2.8 mm and the mean seed implantation error was 2.9 mm. Using the constant rotation and orientation reversal at half insertion depth methods, the deflection error was reduced. The mean needle targeting errors were 0.8 and 1.2 mm for the constant rotation and orientation reversal methods, respectively, and the seed implantation errors were 0.9 and 1.5 mm for constant rotation insertion and orientation reversal methods, respectively
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International Nuclear Information System (INIS)
Tincher, Sandra A.; Kim, Robert Y.; Ezekiel, Mark P.; Zinsli, Tom; Fiveash, John B.; Raben, David A.; Bueschen, Anton J.; Urban, Donald A.
2000-01-01
Purpose: Pubic arch interference due to an enlarged prostate gland or a narrow pubic arch is often a limiting factor in adequate prostate coverage during transperineal brachytherapy. The purpose of this study was to evaluate the effects of both pelvic rotation and needle angles on pubic arch interference using CT-based 3-D information. Methods and Materials: Seven patients had CT imaging in both supine and lithotomy positions and 3-D treatment planning was performed with three needle angles (20 downward, 0, 20 upward). The pubic arch interference was then measured and comparisons were made for each needle trajectory and pelvic position. Results: Increasing pelvic rotation from supine to lithotomy position shows less pubic arch interference. Directing the needle tip upward shows less pubic arch interference in both supine and lithotomy positions when compared to needle tips directed downward. Conclusions: Both pelvic position and needle angles are important factors influencing pubic arch interference. Preplanning CT-based 3-D information may assist for individualized treatment planning in patients with a significant bony interference, thus avoiding pubic arch interference during implantation
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Development of a Silicon Microneedle with Three-Dimensional Sharp Tip by Electrochemical Etching
Izumi, Hayato; Okamoto, Tokusuke; Suzuki, Masato; Aoyagi, Seiji
Aiming at the use in low-invasive medical treatments, this paper reports a fabrication technique of silicon microneedle of conical sharp point. The electrochemical etching technique is employed for sharpening the tip of a pillar, which is diced from a silicon wafer. A finely smooth tip surface is obtained due to electrochemical etching reactions, and is effective for easy insertion. The fabrication method is based on inexpensive wet etching, which does not require expensive fabrication facilities such as deep reactive ion etching (DRIE). A sharp needle was successfully fabricated, the tip angle of which was considerably small and was distributed within the range from 15 to 30 deg. An experiment of inserting the fabricated needle into an artificial skin of silicone rubber was carried out. As the results, the resistance force during insertion was much reduced compared to those of two-dimensional sharp needles. Imitating mosquito's motion, the effectiveness of applying vibration to the fabricated needle during insertion was also confirmed. After biocompatible Parylene coating, puncturing a human skin was demonstrated assuming a lancet usage for the diabetics, in which the bleeding was surely observed.
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Needle twins and right-angled twins in minerals: comparison between experiment and theory
Salje, E.K.H.; Buckley, A.; Van Tendeloo, G.; Ishibashi, Y.; Nord, G.L.
1998-01-01
Transformation twinning in minerals forms isolated twin walls, intesecting walls with corner junctions, and wedge-shaped twins as elements of hierarchical patterns. When cut perpendicular to the twin walls, the twins have characteristic shapes, right-angled and needle-shaped wall traces, which can be observed by transmission electron microscopy or by optical microscopy. Theoretical geometries of wall shapes recently derived for strain-related systems should hold for most displacive and order-disorder type phase transitions: 1) right-angled twins show curved junctions; 2) needle-shaped twins contain flat wall segments near the needle tip if the elastic behaviour of the mineral is dominated by its anisotroyp; 3) additional bending forces and pinning effects lead to curved walls near the junction that make the needle tip appear more blunt. Bent right-angled twins were analyzed in Gd2(MoO4)3. Linear needle tips were found in WO3, [N(CH3)4]2.ZnBr4 CrAl, BiVO4, GdBa2Cu3O7, and PbZrO. Parabolic tips occur in K2Ba(NO2)4, and GeTe whereas exponential curvatures appear in BaTiO3, KSCN, Pb3(PO4)2, CaTiO3, alkali feldspars, YBa2Cu3O7, and MnAl. The size and shape of the twin microstructure relates to its formation during the phase transition and the subsequent annealing history. The mobility of the twin walls after formation depends not only on the thermal activation but also on the structure of the wall, which may be pinned to impurities on a favorable structural site. Depinnign energies are often large compared with thermal energies for diffusion. This leads to kinetic time scales for twin coarsening that are comparable to geological time scales. Therefore, transformation twins that exhibit needle domains not only indicate that the mineral underwent a structural phase transition but also contain information about its subsequent geological history.
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Smartphone-Guided Needle Angle Selection During CT-Guided Procedures.
Xu, Sheng; Krishnasamy, Venkatesh; Levy, Elliot; Li, Ming; Tse, Zion Tsz Ho; Wood, Bradford John
2018-01-01
In CT-guided intervention, translation from a planned needle insertion angle to the actual insertion angle is estimated only with the physician's visuospatial abilities. An iPhone app was developed to reduce reliance on operator ability to estimate and reproduce angles. The iPhone app overlays the planned angle on the smartphone's camera display in real-time based on the smartphone's orientation. The needle's angle is selected by visually comparing the actual needle with the guideline in the display. If the smartphone's screen is perpendicular to the planned path, the smartphone shows the Bull's-Eye View mode, in which the angle is selected after the needle's hub overlaps the tip in the camera. In phantom studies, we evaluated the accuracies of the hardware, the Guideline mode, and the Bull's-Eye View mode and showed the app's clinical efficacy. A proof-of-concept clinical case was also performed. The hardware accuracy was 0.37° ± 0.27° (mean ± SD). The mean error and navigation time were 1.0° ± 0.9° and 8.7 ± 2.3 seconds for a senior radiologist with 25 years' experience and 1.5° ± 1.3° and 8.0 ± 1.6 seconds for a junior radiologist with 4 years' experience. The accuracy of the Bull's-Eye View mode was 2.9° ± 1.1°. Combined CT and smart-phone guidance was significantly more accurate than CT-only guidance for the first needle pass (p = 0.046), which led to a smaller final targeting error (mean distance from needle tip to target, 2.5 vs 7.9 mm). Mobile devices can be useful for guiding needle-based interventions. The hardware is low cost and widely available. The method is accurate, effective, and easy to implement.
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International Nuclear Information System (INIS)
Wonneberger, Uta; Schnackenburg, Bernhard; Streitparth, Florian; Walter, Thula; Rump, Jens; Teichgraeber, Ulf K. M.
2010-01-01
In this article, we study in vitro evaluation of needle artefacts and image quality for musculoskeletal laser-interventions in an open high-field magnetic resonance imaging (MRI) scanner at 1.0T with vertical field orientation. Five commercially available MRI-compatible puncture needles were assessed based on artefact characteristics in a CuSO4 phantom (0.1%) and in human cadaveric lumbar spines. First, six different interventional sequences were evaluated with varying needle orientation to the main magnetic field B0 (0 o to 90 o ) in a sequence test. Artefact width, needle-tip error, and contrast-to-noise ratio (CNR) were calculated. Second, a gradient-echo sequence used for thermometric monitoring was assessed and in varying echo times, artefact width, tip error, and signal-to-noise ratio (SNR) were measured. Artefact width and needle-tip error correlated with needle material, instrument orientation to B0, and sequence type. Fast spin-echo sequences produced the smallest needle artefacts for all needles, except for the carbon fibre needle (width o to B0. Overall, the proton density-weighted spin-echo sequences had the best CNR (CNR Muscle/Needle >16.8). Concerning the thermometric gradient echo sequence, artefacts remained <5 mm, and the SNR reached its maximum at an echo time of 15 ms. If needle materials and sequences are accordingly combined, guidance and monitoring of musculoskeletal laser interventions may be feasible in a vertical magnetic field at 1.0T.
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Mechanics of anesthetic needle penetration into human sciatic nerve.
Pichamuthu, Joseph E; Maiti, Spandan; Gan, Maria G; Verdecchia, Nicole M; Orebaugh, Steven L; Vorp, David A
2018-06-06
Nerve blocks are frequently performed by anesthesiologists to control pain. For sciatic nerve blocks, the optimal placement of the needle tip between its paraneural sheath and epineurial covering is challenging, even under ultrasound guidance, and frequently results in nerve puncture. We performed needle penetration tests on cadaveric isolated paraneural sheath (IPS), isolated nerve (IN), and the nerve with overlying paraneural sheath (NPS), and quantified puncture force requirement and fracture toughness of these specimens to assess their role in determining the clinical risk of nerve puncture. We found that puncture force (123 ± 17 mN) and fracture toughness (45.48 ± 9.72 J m -2 ) of IPS was significantly lower than those for NPS (1440 ± 161 mN and 1317.46 ± 212.45 Jm -2 , respectively), suggesting that it is not possible to push the tip of the block needle through the paraneural sheath only, without pushing it into the nerve directly, when the sheath is lying directly over the nerve. Results of this study provide a physical basis for tangential placement of the needle as the ideal situation for local anesthetic deposition, as it allows for the penetration of the sheath along the edge of the nerve without entering the epineurium. Copyright © 2018 Elsevier Ltd. All rights reserved.
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A microfluidic needle for sampling and delivery of chemical signals by segmented flows
Feng, Shilun; Liu, Guozhen; Jiang, Lianmei; Zhu, Yonggang; Goldys, Ewa M.; Inglis, David W.
2017-10-01
We have developed a microfluidic needle-like device that can extract and deliver nanoliter samples. The device consists of a T-junction to form segmented flows, parallel channels to and from the needle tip, and seven hydrophilic capillaries at the tip that form a phase-extraction region. The main microchannel is hydrophobic and carries segmented flows of water-in-oil. The hydrophilic capillaries transport the aqueous phase with a nearly zero pressure gradient but require a pressure gradient of 19 kPa for mineral oil to invade and flow through. Using this device, we demonstrate the delivery of nanoliter droplets and demonstrate sampling through the formation of droplets at the tip of our device. During sampling, we recorded the fluorescence intensities of the droplets formed at the tip while varying the concentration of dye outside the tip. We measured a chemical signal response time of approximately 3 s. The linear relationship between the recorded fluorescence intensity of samples and the external dye concentration (10-40 μg/ml) indicates that this device is capable of performing quantitative, real-time measurements of rapidly varying chemical signals.
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Ganpule, Arvind P; Deshmukh, Chaitanya S; Joshi, Tanmay
2018-01-01
The challenges in laparoscopic suturing include need to expertise to suture. Laparoscopic needle holder is a" key" instrument to accomplish this arduous task. The objective of this new invention was to develop a laparoscopic needle holder which would be adapted to avoid any wobble (with a shaft diameter same as a 5mm port), ensure accurate and dexterous suturing not just in adult patients but pediatric patients alike (with a short shaft diameter) and finally ensure seamless throw of knots with a narrow tip configuration. We did an initial evaluation to evaluate the validity of the prototype needle holder and its impact on laparoscopic suturing skills by experienced laparoscopic surgeons and novice laparoscopic Surgeons. Both the groups of surgeons performed two tasks. The first task was to grasp the needle and position it in an angle deemed ideal for suturing. The second task was to pass suture through two fixed points and make a single square knot. At the end of the tasks each participant was asked to complete a 5- point Likert's scale questionnaire (8 items; 4 items of handling and 4 items of suturing) rating each needle holder. In expert group, the mean time to complete task 1 was shorter with prototype 3/5 laparoscopic needle holder (11.8 sec Vs 20.8 sec). The mean time to complete task 2 was also shorter with prototype 3/5 laparoscopic needle holder (103.2 sec Vs 153.2 sec). In novice group, mean time to complete both the task was shorter with prototype 3/5 laparoscopic needle holder. The expert laparoscopic surgeons as well as novice laparoscopic surgeons performed laparoscopic suturing faster and with more ease while using the prototype 3/5 laparoscopic needle holder.
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The effects of needle deformation during lumbar puncture
Directory of Open Access Journals (Sweden)
Hasan Hüseyin Özdemir
2015-01-01
Full Text Available Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP. Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1% of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3% of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%. Forty-seven (41.5% patients experienced post lumbar puncture headache (PLPH and 13 (11.5% patients experienced intracranial hypotension (IH. No statistically significant correlation between the degree of deflection and headache was found (P > 0.05. Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH.
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The effects of needle deformation during lumbar puncture
Özdemir, Hasan Hüseyin; Demir, Caner F.; Varol, Sefer; Arslan, Demet; Yıldız, Mustafa; Akil, Eşref
2015-01-01
Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP). Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1%) of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3%) of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%). Forty-seven (41.5%) patients experienced post lumbar puncture headache (PLPH) and 13 (11.5%) patients experienced intracranial hypotension (IH). No statistically significant correlation between the degree of deflection and headache was found (P > 0.05). Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH. PMID:25883480
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Homogeneity of δ15N in needles of Masson pine (Pinus massoniana L.) was altered by air pollution
International Nuclear Information System (INIS)
Kuang Yuanwen; Wen Dazhi; Li Jiong; Sun Fangfang; Hou Enqing; Zhou Guoyi; Zhang Deqiang; Huang Longbin
2010-01-01
The present study investigated the changes of δ 15 N values in the tip, middle and base section (divided by the proportion to needle length) of current- and previous-year needles of Masson pine (Pinus massoniana L.) from two declining forest stands suffering from air pollution, in comparison with one healthy stand. At the healthy stand, δ 15 N in the three sections of both current- and previous-year needles were found evenly distributed, while at the polluted stands, δ 15 N values in the needles were revealed significantly different from the tip to the base sections. The results implied that the distribution of δ 15 N among different parts or sections in foliages was not always homogeneous and could be affected by air pollution. We suggested that the difference of δ 15 N values among pine needle sections should be reconsidered and should not be primarily ignored when the needle δ 15 N values were used to assess plant responses to air pollution. - Values of δ 15 N in needles of Masson pine (Pinus massoniana L.) were uneven and affected by air pollution.
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[Needling technique of Professor Li Yan-Fang].
Li, Li-Jun
2014-01-01
Experiences of needling techniques of Professor LI Ya- fang is introduced in this article. Gentle and superficial insertion is adopted by Professor LI in clinic. Emphases are put on the qi regulation function, needling sensation to the affected region and insertion with both hands, especially the function of the left hand as pressing hand. The gentle and superficial insertion should be done as the follows: hold the needle with the right hand, press gently along the running course of meridians with the left hand to promote qi circulation, hard pressing should be applied at acupoints to disperse the local qi and blood, insert the needle gently and quickly into the subcutaneous region with the right hand, and stop the insertion when patient has the needling sensation. While the fast needling is characterized with shallow insertion and swift manipulation: the left hand of the manipulator should press first along the running course of the meridian, and fix the local skin, hold the needle with the right hand and insert the needle quickly into the acupoint. Withdrawal of the needle should be done immediately after the reinforcing and reducing manipulations. Professor LI is accomplished in qi regulation. It is held by him that regulating qi circulation is essence of acupuncture, letting the patient get the needling sensation is the most important task of needling. Lifting, thrusting and rotation manipulations should be applied to do reinforcing or reducing. The tissue around the tip of the needle should not be too contracted or too relaxed, and the resistance should not be too strong or too weak. The feeling of the insertion hand of the practitioner should not be too smooth or too hesitant. Needle should be inserted into the skin quickly at the moment of hard pressing by the left hand. And then, slow rotation and gentle lifting and thrusting can be applied to promote the needling sensation like electric current pass through and to reach the affected region along the
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Meyer, Jay J; Kuo, Annie F; Olson, Randall J
2010-06-01
To determine capsular breakage risk from contact by phacoemulsification needles by machine and tip type. Experimental laboratory investigation. Infiniti (Alcon, Inc.) with Intrepid cartridges and Signature (Abbott Medical Optics, Inc.) phacoemulsification machines were tested using 19- and 20-gauge sharp and rounded tips. Actual and unoccluded flow vacuum were determined at 550 mm Hg, bottle height of 75 cm, and machine-indicated flow rate of 60 mL/minute. Breakage from brief tip contact with a capsular surrogate and human cadaveric lenses was calculated. Nineteen-gauge tips had more flow and less unoccluded flow vacuum than 20-gauge tips for both machines, with highest unoccluded flow vacuum in the Infiniti. The 19-gauge sharp tip was more likely than the 20-gauge sharp tip to cause surrogate breakage for Signature with micropulse and Ellips (Abbott Medical Optics, Inc.) ultrasound at 100% power. For Infiniti using OZil (Alcon, Inc.) ultrasound, 20-gauge sharp tips were more likely than 19-gauge sharp tips to break the membrane. For cadaveric lenses, using rounded 20-gauge tips at 100% power, breakage rates were micropulse (2.3%), Ellips (2.3%), OZil (5.3%). Breakage rates for sharp 20-gauge Ellips tips were higher than for rounded tips. Factors influencing capsular breakage may include active vacuum at the tip, flow rate, needle gauge, and sharpness. Nineteen-gauge sharp tips were more likely than 20-gauge tips to cause breakage in lower vacuum methods. For higher-vacuum methods, breakage is more likely with 20-gauge than with 19-gauge tips. Rounded-edge tips are less likely than sharp-edged tips to cause breakage. Copyright 2010 Elsevier Inc. All rights reserved.
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An ultrasound needle insertion guide in a porcine phantom model.
Whittaker, S; Lethbridge, G; Kim, C; Keon Cohen, Z; Ng, I
2013-08-01
We compared nerve blockade with and without the Infiniti(TM) needle guide in an ultrasound in-plane porcine simulation. We recruited 30 anaesthetists with varying blockade experience. Using the guide, the needle tip was more visible (for a median (IQR [range]) of 67 (56-100]) % of the time; and invisible for 2 (1-4 [0-19]) s) than when the guide was not used (respectively 23 (13-43 [0-80]) % and 25 (9-52 [1-198]) s; both p < 0.001). The corresponding block times were 8 (6-10 [3-28]) s and 32 (15-67 [5-225]) s, respectively; p < 0.001. The needle guide reduced the block time and the time that the needle was invisible, irrespective of anaesthetist experience. Anaesthesia © 2013 The Association of Anaesthetists of Great Britain and Ireland.
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A needle guidance system for biopsy and therapy using two-dimensional ultrasound
International Nuclear Information System (INIS)
Bluvol, Nathan; Sheikh, Allison; Kornecki, Anat; Del Rey Fernandez, David; Downey, Donal; Fenster, Aaron
2008-01-01
Image-guided needle biopsies are currently used to provide a definitive diagnosis of breast cancer; however, difficulties in tumor targeting exist as the ultrasound (United States) scan plane and biopsy needle must remain coplanar throughout the procedure to display the actual needle tip position. The additional time associated with aligning and maintaining this coplanar relationship results in increased patient discomfort. Biopsy procedural efficiency is further hindered since needle pathway interpretation is often difficult, especially for needle insertions at large depths that usually require multiple reinsertions. The authors developed a system that would increase the speed and accuracy of current breast biopsy procedures using readily available two-dimensional (2D) US technology. This system is composed of a passive articulated mechanical arm that attaches to a 2D US transducer. The arm is connected to a computer through custom electronics and software, which were developed as an interface for tracking the positioning of the mechanical components in real time. The arm couples to the biopsy needle and provides visual guidance for the physician performing the procedure in the form of a real-time projected needle pathway overlay on an US image of the breast. An agar test phantom, with stainless steel targets interspersed randomly throughout, was used to validate needle trajectory positioning accuracy. The biopsy needle was guided by both the software and hardware components to the targets. The phantom, with the needle inserted and device decoupled, was placed in an x-ray stereotactic mammography (SM) machine. The needle trajectory and bead target locations were determined in three dimensions from the SM images. Results indicated a mean needle trajectory accuracy error of 0.75±0.42 mm. This is adequate to sample lesions that are <2 mm in diameter. Chicken tissue test phantoms were used to compare core needle biopsy procedure times between experienced radiologists
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Efficacy of Tuohy Needle in Oocytes Collection from Excised Mare Ovaries
Directory of Open Access Journals (Sweden)
F. Cremonesi
2010-01-01
Full Text Available Two methods have been described to recover oocytes from equine follicles in excised ovaries: aspiration and scraping. Aim of this work was to develop an effective method for collecting equine oocytes using Tuohy needle and comparing this technique to aspiration and scraping, with or without tunica albuginea removal. This hollow hypodermic needle, usually employed for inserting epidural catheters, is designed with a slightly curved tip, shaped similar to a small curette. In unpeeled ovaries, the recovery rates of Tuohy needle group was higher (<.05 than in the 16 g needle aspiration and in the scraped ovaries (57% versus 36% and 47% while the rate of cumulus-intact oocytes was higher than aspiration (46.9% versus 39.36% but lower than scraping (46.97% (<.001. In unpeeled ovaries there was significant difference in maturation rate of oocytes recovered by Tuohy needle in respect to peeled ovaries (58.54% versus 50.17%, resp.. Combination of aspiration and scraping by Tuohy needle allows a faster and reliable collection of oocytes suitable for horse IVM.
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PVA matches human liver in needle-tissue interaction.
de Jong, Tonke L; Pluymen, Loes H; van Gerwen, Dennis J; Kleinrensink, Gert-Jan; Dankelman, Jenny; van den Dobbelsteen, John J
2017-05-01
Medical phantoms can be used to study needle-tissue interaction and to train medical residents. The purpose of this research is to study the suitability of polyvinyl alcohol (PVA) as a liver tissue mimicking material in terms of needle-tissue interaction. Insertions into ex-vivo human livers were used for reference. Six PVA samples were created by varying the mass percentage of PVA to water (4m% and 7m%) and the number of freeze-thaw cycles (1, 2 and 3 cycles, 16hours of freezing at -19°C, 8hours of thawing). The inner needle of an 18 Gauge trocar needle with triangular tip was inserted 13 times into each of the samples, using an insertion velocity of 5 mm/s. In addition, 39 insertions were performed in two ex-vivo human livers. Axial forces on the needle were captured during insertion and retraction and characterized by friction along the needle shaft, peak forces, and number of peak forces per unit length. The concentration of PVA and the number of freeze-thaw cycles both influenced the mechanical interaction between needle and specimen. Insertions into 4m% PVA phantoms with 2 freeze-thaw cycles were comparable to human liver in terms of estimated friction along the needle shaft and the number of peak forces. Therefore, these phantoms are considered to be suitable liver mimicking materials for image-guided needle interventions. The mechanical properties of PVA hydrogels can be influenced in a controlled manner by varying the concentration of PVA and the number of freeze-thaw cycles, to mimic liver tissue characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.
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A variable stiffness mechanism for steerable percutaneous instruments: integration in a needle.
De Falco, Iris; Culmone, Costanza; Menciassi, Arianna; Dankelman, Jenny; van den Dobbelsteen, John J
2018-06-04
Needles are advanced tools commonly used in minimally invasive medical procedures. The accurate manoeuvrability of flexible needles through soft tissues is strongly determined by variations in tissue stiffness, which affects the needle-tissue interaction and thus causes needle deflection. This work presents a variable stiffness mechanism for percutaneous needles capable of compensating for variations in tissue stiffness and undesirable trajectory changes. It is composed of compliant segments and rigid plates alternately connected in series and longitudinally crossed by four cables. The tensioning of the cables allows the omnidirectional steering of the tip and the stiffness tuning of the needle. The mechanism was tested separately under different working conditions, demonstrating a capability to exert up to 3.6 N. Afterwards, the mechanism was integrated into a needle, and the overall device was tested in gelatine phantoms simulating the stiffness of biological tissues. The needle demonstrated the capability to vary deflection (from 11.6 to 4.4 mm) and adapt to the inhomogeneity of the phantoms (from 21 to 80 kPa) depending on the activation of the variable stiffness mechanism. Graphical abstract ᅟ.
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International Nuclear Information System (INIS)
Morawski, Ireneusz; Spiegelberg, Richard; Korte, Stefan; Voigtländer, Bert
2015-01-01
A method which allows scanning tunneling microscopy (STM) tip biasing independent of the sample bias during frequency modulated atomic force microscopy (AFM) operation is presented. The AFM sensor is supplied by an electronic circuit combining both a frequency shift signal and a tunneling current signal by means of an inductive coupling. This solution enables a control of the tip potential independent of the sample potential. Individual tip biasing is specifically important in order to implement multi-tip STM/AFM applications. An extensional quartz sensor (needle sensor) with a conductive tip is applied to record simultaneously topography and conductivity of the sample. The high resonance frequency of the needle sensor (1 MHz) allows scanning of a large area of the surface being investigated in a reasonably short time. A recipe for the amplitude calibration which is based only on the frequency shift signal and does not require the tip being in contact is presented. Additionally, we show spectral measurements of the mechanical vibration noise of the scanning system used in the investigations
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Energy Technology Data Exchange (ETDEWEB)
Morawski, Ireneusz [Peter Grünberg Institut (PGI-3) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425 Jülich (Germany); Institute of Experimental Physics, University of Wrocław, pl. M. Borna 9, 50-204 Wrocław (Poland); Spiegelberg, Richard; Korte, Stefan; Voigtländer, Bert [Peter Grünberg Institut (PGI-3) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425 Jülich (Germany)
2015-12-15
A method which allows scanning tunneling microscopy (STM) tip biasing independent of the sample bias during frequency modulated atomic force microscopy (AFM) operation is presented. The AFM sensor is supplied by an electronic circuit combining both a frequency shift signal and a tunneling current signal by means of an inductive coupling. This solution enables a control of the tip potential independent of the sample potential. Individual tip biasing is specifically important in order to implement multi-tip STM/AFM applications. An extensional quartz sensor (needle sensor) with a conductive tip is applied to record simultaneously topography and conductivity of the sample. The high resonance frequency of the needle sensor (1 MHz) allows scanning of a large area of the surface being investigated in a reasonably short time. A recipe for the amplitude calibration which is based only on the frequency shift signal and does not require the tip being in contact is presented. Additionally, we show spectral measurements of the mechanical vibration noise of the scanning system used in the investigations.
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Precision of Needle Tip Localization Using a Receiver in the Needle
DEFF Research Database (Denmark)
Nikolov, Svetoslav Ivanov; Jensen, Jørgen Arendt
2008-01-01
and investigates their precision. The first method uses conventional imaging. Instead of detecting the maximum echo, as previously suggested, the center of mass is found both across beams and along the received signals, thus decreasing the sensitivity to noise. The second method is based synthetic aperture (SA......) scanning. The position of the tip is found via triangulation which involves solving a system of linear equations. The robustness to noise is ensured through averaging a number of estimates. The sensor is a ring of piezo-electric film making it possible to receive waves from any direction. The results were...... obtained using simulations in Field II. The center frequency is 7 MHz. The transducer array is mechanically focused in elevation plane at 25 mm while the height of the elements is 4.5 mm. The transducer pitch is 202 microns. The sensor is a ring with height of 1 mm and 2 mm diameter. Positions were varied...
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Effect of Blinding With a New Pragmatic Placebo Needle
Liu, Baoyan; Xu, Huanfang; Ma, Rui; Mo, Qian; Yan, Shiyan; Liu, Zhishun
2014-01-01
Abstract Placebo control is a useful method for determining the efficacy of a therapy. In acupuncture researches, the preferred method for placebo control is acupuncture using a placebo needle that has a blunt tip and achieves no skin penetration. We performed a crossover study to validate the blinding effect of a new type of placebo needle. Sixty volunteers were randomized to receive acupuncture using 2 types of needles with different sequences: sequence AB, involving first the pragmatic placebo needle and then the real needle, and sequence BA, in a reverse order. Placebo acupuncture was performed by administering the placebo needle through an adhesive pad without skin penetration on the acupoints LI4, RN12, BL25, and BL36. Real acupuncture was performed by needling through the pad and penetrating the skin to 15 mm using a real needle on the same acupoints. The acupuncture was administered every other day with 3 sessions for 1 type of needle. The primary outcome was the perception of needle penetration. Besides degree of acupuncture pain, type, and degree of needle sensation, needle acceptability and factors influencing the subject blinding effect were assessed. Needle penetration was felt by 100%, 90% (54/60), 88.3% (53/60), and 95% (57/60) of volunteers receiving placebo acupuncture and 98.3% (59/60), 96.7% (58/60), 95% (57/60), and 95% (57/60) of volunteers receiving real acupuncture on LI4, RN12, BL25, and BL36, respectively. Differences of the volunteers’ perception of needle penetration between the placebo needle and real needle were not significant for the 4 acupoints (all P > 0.05). Volunteers experienced fewer distension sensations (P = 0.01), a lower degree of needle sensation (P = 0.007), and less pain (P = 0.006) during placebo acupuncture than during real acupuncture. The placebo needle was more easily accepted than the real needle (OR = 1.63, 95% CI, 1.01–2.64). The influences of age, sex, educational level, acupuncture
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Directory of Open Access Journals (Sweden)
Brian Johnson
2014-09-01
Full Text Available Introduction: Ultrasound-guided nerve blocks (UGNB are increasingly used in emergency care. The hand-on-syringe (HS needle technique is ideally suited to the emergency department setting because it allows a single operator to perform the block without assistance. The HS technique is assumed to provide less exact needle control than the alternative two-operator hand-on-needle (HN technique; however this assumption has never been directly tested. The primary objective of this study was to compare accuracy of needle targeting under ultrasound guidance by emergency medicine (EM residents using HN and HS techniques on a standardized gelatinous simulation model. Methods: This prospective, randomized study evaluated task performance. We compared needle targeting accuracy using the HN and HS techniques. Each participant performed a set of structured needling maneuvers (both simple and difficult on a standardized partial-task simulator. We evaluated time to task completion, needle visualization during advancement, and accuracy of needle tip at targeting. Resident technique preference was assessed using a post-task survey. Results: We evaluated 60 tasks performed by 10 EM residents. There was no significant difference in time to complete the simple model (HN vs. HS, 18 seconds vs. 18 seconds, p=0.93, time to complete the difficult model (HN vs. HS, 56 seconds vs. 50 seconds, p=0.63, needle visualization, or needle tip targeting accuracy. Most residents (60% preferred the HS technique. Conclusion: For EM residents learning UGNBs, the HN technique was not associated with superior needle control. Our results suggest that the single-operator HS technique provides equivalent needle control when compared to the two-operator HN technique. [West J Emerg Med. 2014;15(6:641–646
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Becker, Otávio Monteiro; Azevedo, João Luiz Moreira Coutinho; de Azevedo, Otávio Cansanção; Hypólito, Octávio Henrique Mendes; Miyahira, Susana Abe; Miguel, Gustavo Peixoto Soares; Machado, Afonso Cesar Cabral Guedes
2011-01-01
To assess the effectiveness of the Veress needle puncture in the left hypochondrium and the accuracy of the tests described for the intraperitoneal correct positioning of the tip of the Veress needle in an unselected population. Ninetyone patients consecutively scheduled for Videolaparoscopy had the abdominal wall punctured in the left hypochondrium. There were no exclusion criteria. The patients received general anesthesia and mechanical ventilation according to the protocol. After puncturing five tests were used to confirm the positioning of the needle tip within the peritoneal cavity: aspiration test--AT; resistance to infusion--Pres; recovery of the infused fluid--Prec, dripping test--DT, and test of initial intraperitoneal pressure--IIPP. The test results were compared with results from literature for groups with defined exclusion criteria. The results were used for calculating sensitivity (S) specificity (E), positive predictive value (PPV) and negative predictive value (NPV). Inferential statistical methods were used to analyze the findings. There were 13 failures. AT had E = 100% and NPV 100%. Pres had S = 100%, E = 0; PPV = 85.71%; NPV does not apply. Prec: S = 100%, E = 53.84%, PPV = 92.85%, NPV = 100%. DT: S = 100%, E = 61.53%, PPV = 93.97% NPV 100%. In IIPP, S, E, PPV and NPV were 100%. The puncture in the left hypochondrium is effective and the performed tests guide the surgeon regardless of sex, BMI, or previous laparotomy.
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Molecular model of a type III secretion system needle: Implications for host-cell sensing.
Deane, Janet E; Roversi, Pietro; Cordes, Frank S; Johnson, Steven; Kenjale, Roma; Daniell, Sarah; Booy, Frank; Picking, William D; Picking, Wendy L; Blocker, Ariel J; Lea, Susan M
2006-08-15
Type III secretion systems are essential virulence determinants for many Gram-negative bacterial pathogens. The type III secretion system consists of cytoplasmic, transmembrane, and extracellular domains. The extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. Effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid infection. Physical contact with host cells initiates secretion and leads to formation of a pore, thought to be contiguous with the needle channel, in the host-cell membrane. Here, we report the crystal structure of the Shigella flexneri needle subunit MxiH and a complete model for the needle assembly built into our three-dimensional EM reconstruction. The model, combined with mutagenesis data, reveals that signaling of host-cell contact is relayed through the needle via intersubunit contacts and suggests a mode of binding for a tip complex.
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Mali, K. D.; Singru, P. M.
2018-03-01
In this work effect of the impact location and the type of hammer tip on the frequency response function (FRF) is studied. Experimental modal analysis of rectangular plates is carried out for this purpose by using impact hammer, accelerometer and fast Fourier transform (FFT) analyzer. It is observed that the impulse hammer hit location has, no effect on the eigenfrequency, yet a difference in amplitude of the eigenfrequencies is obtained. The effect of the hammer tip on the pulse and the force spectrum is studied for three types of tips metal, plastic and rubber. A solid rectangular plate was excited by using these tips one by one in three different tests. It is observed that for present experimental set up plastic tip excites the useful frequency range.
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Rodgers, Jessica Robin; Surry, Kathleen; Leung, Eric; D'Souza, David; Fenster, Aaron
2017-05-01
postinsertion CT scan based on the vaginal cylinder of the needle template. The positions of the tips and the trajectory of the needle paths were compared between the modalities. The observed geometric errors of the system were ≤ 0.3 mm in each of the three coordinate planes of the 3D US image and the mean measured volumetric error was 0.10 cm 3 . In the phantom study, the mean needle tip difference was 1.54 ± 0.71 mm and the mean trajectory difference was 0.94 ± 0.89 degrees (n = 14). In the in vivo study, a total of 73 needles were placed, of which 88% of needles were visible and 79% of tips were identifiable in the 3D TRUS images. Six of the nine needles that were not visible were due to shadowing artifacts created by the presence of the vaginal cylinder of the needle template. The mean distance between corresponding needle tips in the two modalities was 3.82 ± 1.86 mm and the mean trajectory difference was 3.04 ± 1.63 degrees for the five patients. In this proof-of-concept study, the 3D TRUS system allowed for localization of needles not obscured by shadowing artifacts, providing a method for visualizing needles intra-operatively during HDR interstitial brachytherapy of gynecologic cancers and providing the potential for 3D image-guidance. © 2017 American Association of Physicists in Medicine.
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Elsharkawy, Hesham; Saasouh, Wael; Patel, Bimal; Babazade, Rovnat
2018-04-01
Currently, no gold standard method exists for localization of an epidural catheter after placement. The technique described in this report uses pulsed-wave Doppler (PWD) ultrasound to identify intrathecal location of an epidural catheter. A thoracic epidural catheter was inserted after multiple trials with inconclusive aspiration and test dose. Ultrasound PWD confirmed no flow in the epidural space and positive flow in the intrathecal space. A fluid aspirate was positive for glucose, reconfirming intrathecal placement. PWD is a potential tool that can be used to locate the tip of an epidural catheter.
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Directory of Open Access Journals (Sweden)
Prais Wes A
2008-10-01
Full Text Available Abstract Background To reduce injection pain and improve satisfaction, a thinner (29-gauge [29G], sharper (5-bevel needle than the 27G/3-bevel needle used previously to inject interferon (IFN beta-1a, 44 or 22 mcg subcutaneously (sc three times weekly (tiw, was developed for use in multiple sclerosis (MS. Methods Two clinical trials in healthy volunteers and five surveys of patients with MS were conducted to assess whether the 29G/5-bevel needle with a Thermo Plastic Elastomer (TPE needle shield (a sleeve that houses the tip of the needle in a secure location is an improvement over the 27G/3-bevel needle with a rubber shield for injection of IFN beta-1a, 44 or 22 mcg sc tiw. Parameters assessed were: pain and ease of insertion (healthy volunteer and nurse responses on subjective pain measurement scales; and patient satisfaction (surveys of patients with MS. Results In healthy volunteers, the 29G/5-bevel needle with TPE shield was associated with the least perceived pain on the Visual Analog Scale (VAS and Verbal VAS (VB-VAS; mean VAS pain scores decreased by 40% and skin penetration improved by 69% compared with the 27G/3-bevel needle with standard rubber shield (p Conclusion Together these studies indicate that the 29G/5-bevel needle with the TPE shield is an improvement over the 27G/3-bevel needle with standard rubber shield in terms of pain, ease of insertion and patient satisfaction. These improvements are expected to result in improved compliance in patients with MS treated with IFN beta-1a, 44 or 22 mcg sc tiw.
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Li, Zhihua
This research was focused on the development of electrical techniques for soil characterization and soil dynamic behavior assessment. The research carried out mainly includes (1) development of a needle probe tool for assessment of soil spatial variability in terms of porosity with high-resolution in the centrifuge testing; (2) development of an electro-location technique to accurately detect buried objects' movements inside the soil during dynamic events; (3) collaborative development of a new electrode switching system to implement electrical resistivity tomography, and electro-location with high speed and high resolution. To assess soil spatial variability with high-resolution, electrical needle probes with different tip shapes were developed to measure soil electrical resistivity. After normalizing soil resistivity by pore fluid resistivity, this information can be correlated to soil porosity. Calibrations in laboratory prepared soils were conducted. Loosening due to insertion of needle probes was evaluated. A special needle probe tool, along with data acquisition and data processing tools were developed to be operated by the new NEES robot on the centrifuge. The needle probes have great potential to resolve interfaces between soil layers and small local porosity variations with a spatial resolution approximately equal to the spacing between electrodes (about half of the probe diameter). A new electrode switching system was developed to accurately detect buried objects' movements using a new electro-location scheme. The idea was to establish an electromagnetic field in a centrifuge model by injecting low-frequency alternating currents through pairs of boundary electrodes. The locations of buried objects are related to the potentials measured on them. A closed form expression for the electric field in a rectangular specimen with insulated boundaries was obtained based on the method of images. Effects of sampling parameters on spatial resolution and tradeoffs
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Presentation of a needle for direct or percutaneous myocardium stem cells injection
Directory of Open Access Journals (Sweden)
Nathan Valle Soubihe Junior
2013-09-01
Full Text Available The instrument has a locking mechanism and is composed of an external needle with blunt tip, with multiple 0.5 mm diameter holes. Internally it is fitted with a mandrill needle, which can be mobilized inside occluding or releasing the lateral holes. The procedure for producing micro lesions is done by exchanging the blunt mandrill for a brush-mandrill, provided with micro bristles that are structurally designed to fill the holes with small exteriorization of bristles. As an option to brush mandrill there is a second self-expandable feather shaped mandrill.
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Geographical and climatic limits of needle types of one- and two-needled pinyon pines
Cole, K.L.; Fisher, J.; Arundel, S.T.; Cannella, J.; Swift, S.
2008-01-01
Aim: The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. Location: Western North America. Methods: We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. Results: The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes
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Effects of insertion speed and trocar stiffness on the accuracy of needle position for brachytherapy
Energy Technology Data Exchange (ETDEWEB)
McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J. [Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, State College, Pennsylvania 16802 (United States); Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 and Mechanical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2012-04-15
Purpose: In prostate brachytherapy, accurate positioning of the needle tip to place radioactive seeds at its target site is critical for successful radiation treatment. During the procedure, needle deflection leads to seed misplacement and suboptimal radiation dose to cancerous cells. In practice, radiation oncologists commonly use high-speed hand needle insertion to minimize displacement of the prostate as well as the needle deflection. Effects of speed during needle insertion and stiffness of trocar (a solid rod inside the hollow cannula) on needle deflection are studied. Methods: Needle insertion experiments into phantom were performed using a 2{sup 2} factorial design (2 parameters at 2 levels), with each condition having replicates. Analysis of the deflection data included calculating the average, standard deviation, and analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: The stiffer tungsten carbide trocar is effective in reducing the average and standard deviation of needle deflection. The fast insertion speed together with the stiffer trocar generated the smallest average and standard deviation for needle deflection for almost all cases. Conclusions: The combination of stiff tungsten carbide trocar and fast needle insertion speed are important to decreasing needle deflection. The knowledge gained from this study can be used to improve the accuracy of needle insertion during brachytherapy procedures.
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Toward Transoral Peripheral Lung Access: Combining Continuum Robots and Steerable Needles.
Swaney, Philip J; Mahoney, Arthur W; Hartley, Bryan I; Remirez, Andria A; Lamers, Erik; Feins, Richard H; Alterovitz, Ron; Webster, Robert J
2017-03-01
Lung cancer is the most deadly form of cancer in part because of the challenges associated with accessing nodules for diagnosis and therapy. Transoral access is preferred to percutaneous access since it has a lower risk of lung collapse, yet many sites are currently unreachable transorally due to limitations with current bronchoscopic instruments. Toward this end, we present a new robotic system for image-guided trans-bronchoscopic lung access. The system uses a bronchoscope to navigate in the airway and bronchial tubes to a site near the desired target, a concentric tube robot to move through the bronchial wall and aim at the target, and a bevel-tip steerable needle with magnetic tracking to maneuver through lung tissue to the target under closed-loop control. In this work, we illustrate the workflow of our system and show accurate targeting in phantom experiments. Ex vivo porcine lung experiments show that our steerable needle can be tuned to achieve appreciable curvature in lung tissue. Lastly, we present targeting results with our system using two scenarios based on patient cases. In these experiments, phantoms were created from patient-specific computed tomography information and our system was used to target the locations of suspicious nodules, illustrating the ability of our system to reach sites that are traditionally inaccessible transorally.
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International Nuclear Information System (INIS)
Degirmenci, B.; Haktanir, A.; Albayrak, R.; Acar, M.; Sahin, D.A.; Sahin, O.; Yucel, A.; Caliskan, G.
2007-01-01
Aim: To evaluate the effects of sonographic characteristics of thyroid nodules, the diameter of needle used for sampling, and sampling technique on obtaining sufficient cytological material (SCM). Materials and methods: We performed sonography-guided fine-needle biopsy (FNB) in 232 solid thyroid nodules. Size-, echogenicity, vascularity, and localization of all nodules were evaluated by Doppler sonography before the biopsy. Needles of size 20, 22, and 24 G were used for biopsy. The biopsy specimen was acquired using two different methods after localisation. In first method, the needle tip was advanced into the nodule in various positions using a to-and-fro motion whilst in the nodule, along with concurrent aspiration. In the second method, the needle was advanced vigorously using a to-and-fro motion within the nodule whilst being rotated on its axis (capillary-action technique). Results: The mean nodule size was 2.1 ± 1.3 cm (range 0.4-7.2 cm). SCM was acquired from 154 (66.4%) nodules by sonography-guided FNB. In 78 (33.6%) nodules, SCM could not be collected. There was no significant difference between nodules with different echogenicity and vascularity for SCM. Regarding the needle size, the lowest rate of SCM was obtained using 20 G needles (56.6%) and the highest rate of adequate material was obtained using 24 G needles (82.5%; p = 0.001). The SCM rate was 76.9% with the capillary-action technique versus 49.4% with the aspiration technique (p < 0.001). Conclusion: Selecting finer needles (24-25 G) for sonography-guided FNB of thyroid nodules and using the capillary-action technique decreased the rate of inadequate material in cytological examination
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[Professor WU Zhongchao's experience of penetration needling].
Zhang, Ning; Wang, Bing; Zhou, Yu
2016-08-12
Professor WU Zhongchao has unique application of penetration needling in clinical treatment. Professor WU applies penetration needling along meridians, and the methods of penetration needling include self-meridian penetration, exterior-interior meridian penetration, identical-name meridian penetration, different meridian penetration. The meridian differentiation is performed according to different TCM syndromes, locations and natures of diseases and acupoint nature, so as to make a comprehensive assessment. The qi movement during acupuncture is focused. In addition, attention is paid on anatomy and long-needle penetration; the sequence and direction of acupuncture is essential, and the reinforcing and reducing methods have great originality, presented with holding, waiting, pressing and vibrating. Based on classical acupoint, the acupoint of penetration needling is flexible, forming unique combination of acupoints.
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Energy Technology Data Exchange (ETDEWEB)
Beaulieu, L.; Racine, E.; Boutaleb, S.; Filion, O. [Département de Radio-Oncologie et Centre de Recherche du CHU de Québec, CHU de Québec, Québec (Québec), and Département de Physique, de Génie Physique et d' Optique et Centre de recherche en sur le Cancer, Université Laval, Québec (Québec) (Canada); Poulin, E.; Hautvast, G. [Biomedical Systems, Philips Group Innovation, High Tech Campus 34 (HTC 34), Eindhoven (Netherlands); Binnekamp, D. [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best (Netherlands)
2014-08-15
In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm{sup 3}). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications.
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International Nuclear Information System (INIS)
Beaulieu, L.; Racine, E.; Boutaleb, S.; Filion, O.; Poulin, E.; Hautvast, G.; Binnekamp, D.
2014-01-01
In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm 3 ). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications
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Pictorial essay: trans-jugular intra-hepatic porto-systemic shunt (TIPS)
International Nuclear Information System (INIS)
Rao Anuradha, T.N.; Rastogi, H.; Pandey, U.C.
2001-01-01
TIPS is an interventional radiologic method of creating a portosystemic shunt by percutaneous means. It is a relatively new weapon in the armamentarium of the management of portal hypertension with variceal bleeding or intractable ascites. Using needles, angioplasty balloon catheters and expandable metallic stents, a shunt is established directly inside the liver parenchyma connecting a large hepatic vein with a main portal vein branch. Depending on the diameter of the expandable stent used, the created TIPS diverts various amounts of portal blood into the systemic circulation and results in significant portal decompression, cessation of hemorrhage from esophageal varices and resolution of ascites. TIPS is not only an effective and safe alternative to shunt surgery but is life saving in cases of variceal hemorrhage. The use of TIPS seems to be a valid alternative to surgery and has several advantages over either esophageal transection or surgical shunts. TIPS avoids a general anesthetic, laparotomy, and disruption of the hepatic venous system that may adversely affect subsequent hepatic transplantation. TIPS has been performed on patients without interfering with successful transplantation
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Electron beam fabrication and characterization of high- resolution magnetic force microscopy tips
Ruhrig, M.; Rührig, M.; Porthun, S.; Porthun, S.; Lodder, J.C.; Mc vitie, S.; Heyderman, L.J.; Johnston, A.B.; Chapman, J.N.
1996-01-01
The stray field, magnetic microstructure, and switching behavior of high‐resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a
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Tang, Lina; Du, Danxin; Yang, Fan; Liang, Zhong; Ning, Yong; Wang, Hua; Zhang, Guo-Jun
2015-06-01
We report a unique nanosensing platform by combining modern nanotechnology with traditional acupuncture needle to prepare graphene-modified acupuncture needle (G-AN), and using it for sensitive detection of neurotransmitters via electrochemistry. An electrochemical deposition method was employed to deposit Au nanoparticles (AuNPs) on the tip surface of the traditional acupuncture needle, while the other part of the needle was coated with insulation paste. Subsequently, the G-AN was obtained by cyclic voltammetry reduction of a graphene oxide solution on the surface of the AuNPs. To investigate the sensing property of the G-AN, pH dependence was measured by recording the open circuit potential in the various pH buffer solutions ranging from 2.0 to 10.0. What’s more, the G-AN was further used for detection of dopamine (DA) with a limit of detection of 0.24 μM. This novel G-AN exhibited a good sensitivity and selectivity, and could realize direct detection of DA in human serum.
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International Nuclear Information System (INIS)
Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun
2017-01-01
To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments
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Energy Technology Data Exchange (ETDEWEB)
Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)
2017-01-15
To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments.
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Microfabricated microneedle with porous tip for drug delivery
Ji, Jing; Tay, Francis E. H.; Miao, Jianmin; Iliescu, Ciprian
2006-05-01
This paper presents a novel approach to fabrication of a silicon microneedle array with porous tips. Dry etching technology with SF6/O2 gas by STS's inductively coupled plasma (ICP) etch tool was used to achieve the pyramidal needle structure. A thin silicon nitride layer was deposited after a thick photoresist layer was coated and reflowed at 120 °C. The silicon nitride layer and residual photoresist on the tips of the pyramidal structures were removed using reactive ion etching (RIE). Electrochemical etching in MeCN/HF was carried out to generate porous silicon on the tips of the microneedles. The fabricated microneedle array has potential applications in drug delivery, since the porous tips can be loaded with a high molecular weight drug. Analytic solutions to the critical loadings of the fabricated microneedle structure are also presented. The variations of the square cross-section were expressed as a function of the axial coordinate to analyze the bending normal stress and critical buckling loading. This analytic method can also be used for other microneedle structures with different cross-sections.
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Oblique needle segmentation and tracking for 3D TRUS guided prostate brachytherapy
International Nuclear Information System (INIS)
Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron
2005-01-01
An algorithm was developed in order to segment and track brachytherapy needles inserted along oblique trajectories. Three-dimensional (3D) transrectal ultrasound (TRUS) images of the rigid rod simulating the needle inserted into the tissue-mimicking agar and chicken breast phantoms were obtained to test the accuracy of the algorithm under ideal conditions. Because the robot possesses high positioning and angulation accuracies, we used the robot as a ''gold standard,'' and compared the results of algorithm segmentation to the values measured by the robot. Our testing results showed that the accuracy of the needle segmentation algorithm depends on the needle insertion distance into the 3D TRUS image and the angulations with respect to the TRUS transducer, e.g., at a 10 deg. insertion anglulation in agar phantoms, the error of the algorithm in determining the needle tip position was less than 1 mm when the insertion distance was greater than 15 mm. Near real-time needle tracking was achieved by scanning a small volume containing the needle. Our tests also showed that, the segmentation time was less than 60 ms, and the scanning time was less than 1.2 s, when the insertion distance into the 3D TRUS image was less than 55 mm. In our needle tracking tests in chicken breast phantoms, the errors in determining the needle orientation were less than 2 deg. in robot yaw and 0.7 deg. in robot pitch orientations, for up to 20 deg. needle insertion angles with the TRUS transducer in the horizontal plane when the needle insertion distance was greater than 15 mm
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Accuracy and complications of CT-guided core needle biopsy of peripheral nerve sheath tumours
Energy Technology Data Exchange (ETDEWEB)
Pianta, Marcus; Chock, Eric; Schlicht, Stephen [St Vincent' s Hospital, Fitzroy, VIC (Australia); McCombe, David [St Vincent' s Hospital and Victorian Hand Surgery Associates, Victoria (Australia)
2015-09-15
This single-centre study retrospectively reviews the complications in patients that have occurred following peripheral nerve sheath tumour biopsy, and assesses whether there is an association with biopsy technique or underlying lesion characteristics. 41 consecutive core needle biopsies of proven peripheral nerve sheath tumours over a 2-year period in a tertiary teaching hospital were reviewed. Patient demographics and symptoms, tumour characteristics and radiological appearances were recorded. Biopsy and surgical histology were correlated, and post-biopsy and surgical complications analyzed. 41 biopsies were performed in 38 patients. 68 % schwannomas, 24 % neurofibromas and 7 % malignant peripheral nerve sheath tumours. Biopsy histology correlated with surgery in all cases. 71 % of lesions were surgically excised. 60 % of patients reported pain related to their lesion. Following the biopsy, 12 % reported increased pain, which resolved in all cases. Pain exacerbation was noted in tumours smaller in size, more superficial and in closer proximity of the biopsy needle tip to the traversing nerve. Number of biopsy needle passes was not associated with an increased incidence of procedure-related pain. Core biopsy of a suspected peripheral nerve sheath tumour may be performed safely before excisional surgery to confirm lesion histology and assist prognosis. There is excellent correlation between core biopsy and excised surgical specimen histology. The most common complication of pain exacerbation is seen in a minority and is temporary, and more likely with smaller, more superficial lesions and a closer needle-tip to traversing nerve distance during biopsy. (orig.)
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Accuracy and complications of CT-guided core needle biopsy of peripheral nerve sheath tumours
International Nuclear Information System (INIS)
Pianta, Marcus; Chock, Eric; Schlicht, Stephen; McCombe, David
2015-01-01
This single-centre study retrospectively reviews the complications in patients that have occurred following peripheral nerve sheath tumour biopsy, and assesses whether there is an association with biopsy technique or underlying lesion characteristics. 41 consecutive core needle biopsies of proven peripheral nerve sheath tumours over a 2-year period in a tertiary teaching hospital were reviewed. Patient demographics and symptoms, tumour characteristics and radiological appearances were recorded. Biopsy and surgical histology were correlated, and post-biopsy and surgical complications analyzed. 41 biopsies were performed in 38 patients. 68 % schwannomas, 24 % neurofibromas and 7 % malignant peripheral nerve sheath tumours. Biopsy histology correlated with surgery in all cases. 71 % of lesions were surgically excised. 60 % of patients reported pain related to their lesion. Following the biopsy, 12 % reported increased pain, which resolved in all cases. Pain exacerbation was noted in tumours smaller in size, more superficial and in closer proximity of the biopsy needle tip to the traversing nerve. Number of biopsy needle passes was not associated with an increased incidence of procedure-related pain. Core biopsy of a suspected peripheral nerve sheath tumour may be performed safely before excisional surgery to confirm lesion histology and assist prognosis. There is excellent correlation between core biopsy and excised surgical specimen histology. The most common complication of pain exacerbation is seen in a minority and is temporary, and more likely with smaller, more superficial lesions and a closer needle-tip to traversing nerve distance during biopsy. (orig.)
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Energy Technology Data Exchange (ETDEWEB)
Shen, S; Kim, R; Benhabib, S; Araujo, J; Burnett, L; Duan, J; Popple, R; Wu, X; Cardan, R; Brezovich, I [UniversityAlabama Birmingham, Birmingham, AL (United Kingdom)
2014-06-01
Purpose: HDR brachytherapy using interstitial needle template for cervical cancer is commonly delivered in 4-5 fractions. Routine verification of needle positions before each fraction is often based on radiographic imaging of implanted fiducial markers. The current study evaluated interfractional displacement of implanted fiducial markers using CT images. Methods: 9 sequential patients with cervical interstitial needle implants were evaluated. The superior and inferior borders of the target volumes were defined by fiducial markers in planning CT. The implant position was verified with kV orthogonal images before each fraction. A second CT was acquired prior 3rd fraction (one or 2 days post planning CT). Distances from inferior and superior fiducial markers to pubic symphysis plane (perpendicular to vaginal obtulator)were measured. Distance from needle tip of a reference needle (next to the inferior marker) to the pubic symphysis plane was also determined. The difference in fiducial marker distance or needle tip distance between planning CT and CT prior 3rd fraction were measured to assess markers migration and needle displacement. Results: The mean inferior marker displacement was 4.5 mm and ranged 0.9 to 11.3 mm. The mean superior marker displacement was 2.7 mm and ranged 0 to 10.4 mm. There was a good association between inferior and superior marker displacement (r=0.95). Mean averaged inferior and superior marker displacement was 3.3 mm and ranged from 0.1 to 10.9 mm, with a standard deviation of 3.2 mm. The mean needle displacement was 5.6 mm and ranged 0.2 to 15.6 mm. Needle displacements were reduced (p<0.05) after adjusting according to needle-to-fiducials distance. Conclusion: There were small fiducial marker displacements between HDR fractions. Our study suggests a target margin of 9.7 mm to cover interfractional marker displacements (in 95% cases) for pretreatment verification based on radiographic imaging.
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Electron beam fabrication and characterization of high-resolution magnetic force microscopy tips
Rührig, M.; Porthun, S.; Lodder, J. C.; McVitie, S.; Heyderman, L. J.; Johnston, A. B.; Chapman, J. N.
1996-03-01
The stray field, magnetic microstructure, and switching behavior of high-resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a thermally evaporated magnetic thin film are transparent to the electron energies used in these TEMs it is possible to observe both the external stray field emanating from the tips as well as their internal domain structure. The experiments confirm the basic features of electron beam fabricated thin film tips concluded from various MFM observations using these tips. Only a weak but highly concentrated stray field is observed emanating from the immediate apex region of the tip, consistent with their capability for high resolution. It also supports the negligible perturbation of the magnetization sample due to the tip stray field observed in MFM experiments. Investigation of the magnetization distributions within the tips, as well as preliminary magnetizing experiments, confirm a preferred single domain state of the high aspect ratio tips. To exclude artefacts of the observation techniques both nonmagnetic tips and those supporting different magnetization states are used for comparison.
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Kao, Meng-Chun; Ting, Chien-Kun; Kuo, Wen-Chuan
2018-02-01
Incorrect placement of the needle causes medical complications in the epidural block, such as dural puncture or spinal cord injury. This study proposes a system which combines an optical coherence tomography (OCT) imaging probe with an automatic identification (AI) system to objectively identify the position of the epidural needle tip. The automatic identification system uses three features as image parameters to distinguish the different tissue by three classifiers. Finally, we found that the support vector machine (SVM) classifier has highest accuracy, specificity, and sensitivity, which reached to 95%, 98%, and 92%, respectively.
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Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access.
Hernandez, D J; Sinkov, V A; Roberts, W W; Allaf, M E; Patriciu, A; Jarrett, T W; Kavoussi, L R; Stoianovici, D
2001-10-01
The traditional method of percutaneous renal access requires freehand needle placement guided by C-arm fluoroscopy, ultrasonography, or computerized tomography. This approach provides limited objective means for verifying successful access. We developed an impedance based percutaneous Smart Needle system and successfully used it to confirm collecting system access in ex vivo porcine kidneys. The Smart Needle consists of a modified 18 gauge percutaneous access needle with the inner stylet electrically insulated from the outer sheath. Impedance is measured between the exposed stylet tip and sheath using Model 4275 LCR meter (Hewlett-Packard, Sunnyvale, California). An ex vivo porcine kidney was distended by continuous gravity infusion of 100 cm. water saline from a catheter passed through the parenchyma into the collecting system. The Smart Needle was gradually inserted into the kidney to measure depth precisely using a robotic needle placement system, while impedance was measured continuously. The Smart Needle was inserted 4 times in each of 4 kidneys. When the needle penetrated the distended collecting system in 11 of 16 attempts, a characteristic sharp drop in resistivity was noted from 1.9 to 1.1 ohm m. Entry into the collecting system was confirmed by removing the stylet and observing fluid flow from the sheath. This characteristic impedance change was observed only at successful entry into the collecting system. A characteristic sharp drop in impedance signifies successful entry into the collecting system. The Smart Needle system may prove useful for percutaneous kidney access.
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International Nuclear Information System (INIS)
Ueda, Kazushige; Ohkawara, Tohru; Minami, Masahito; Sawa, Yoshihiko; Morinaga, Osamu; Kohli, Yoshihiro; Ohkawara, Yasuo
2000-01-01
The purpose of this study is to evaluate the feasibility of transpulmonary CT-guided percutaneous ethanol injection therapy (CT-PEIT) for hepatocellular carcinoma (HCC, 15 lesions) located in the subphrenic region and untreatable by ultrasonography-guided PEIT. The HCC was localized on Lipiodol CT image with a graduated grid system. We advanced a PEIT needle in a stepwise fashion, perpendicularly to the major axis of body through the lung with intermittent localization scans to position the tip of the needle in the lesion. Ethanol was injected with monitoring scans obtained after incremental volumes of injection, until perfusion was judged to be complete. A total of 20 CT-PEIT sessions were performed. The average number of needles passed from skin to liver in each CT-PEIT session was 2.7, the average volume of ethanol injected was 11.7 ml, and the average time required was 53.6 minutes. Complete perfusion of the lesion by ethanol was achieved in all lesions with only a single or double CT-PEIT procedure without severe complications. Local recurrence was detected in 3 to 15 followed up lesions for 14 months on average. In conclusion, transpulmonary CT-PEIT should prove to be a feasible, acceptable treatment for challenging cases of HCC located in the subphrenic region. (author)
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Novel air-injection technique to locate the medial cut end of lacerated canaliculus.
Liu, Bingqian; Li, Yonghao; Long, Chongde; Wang, Zhonghao; Liang, Xuanwei; Ge, Jian; Wang, Zhichong
2013-12-01
Locating the medial cut end of the severed canaliculus is the most difficult aspect of canalicular repair, especially in patients with more medial laceration, severe oedema, persistent errhysis and a narrow canaliculus. Irrigation is a widely used technique to identify the cut end; however, we found that air injected through the intact canaliculus with a straight needle failed to reflux when the common canaliculus or lacrimal sac was not blocked. We describe a simple, safe and efficient air-injection technique to identify the medial cut edge of a lacerated canaliculus. In this method, we initially submersed the medial canthus under normal saline, then injected filtered air through the intact canaliculus using a side port stainless steel probe with a closed round tip. The tip was designed to block the common canaliculus to form a relatively closed system. The efficiency of this novel air-injection technique was equivalent to the traditional technique but does not require the cooperation of the patient to blow air. Using this technique, the medial cut end was successfully identified by locating the air-bubble exit within minutes in 19 cases of mono-canalicular laceration without any complication.
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Electromagnetic-Tracked Biopsy under Ultrasound Guidance: Preliminary Results
International Nuclear Information System (INIS)
Hakime, Antoine; Deschamps, Frederic; Marques De Carvalho, Enio Garcia; Barah, Ali; Auperin, Anne; Baere, Thierry De
2012-01-01
Purpose: This study was designed to evaluate the accuracy and safety of electromagnetic needle tracking for sonographically guided percutaneous liver biopsies. Methods: We performed 23 consecutive ultrasound-guided liver biopsies for liver nodules with an electromagnetic tracking of the needle. A sensor placed at the tip of a sterile stylet (18G) inserted in a coaxial guiding trocar (16G) used for biopsy was localized in real time relative to the ultrasound imaging plane, thanks to an electromagnetic transmitter and two sensors on the ultrasound probe. This allows for electronic display of the needle tip location and the future needle path overlaid on the real-time ultrasound image. Distance between needle tip position and its electronic display, number of needle punctures, number of needle pull backs for redirection, technical success (needle positioned in the target), diagnostic success (correct histopathology result), procedure time, and complication were evaluated according to lesion sizes, depth and location, operator experience, and “in-plane” or “out-of-plane” needle approach. Results: Electronic display was always within 2 mm from the real position of the needle tip. The technical success rate was 100%. A single needle puncture without repuncture was used in all patients. Pull backs were necessary in six patients (26%) to obtain correct needle placement. The overall diagnostic success rate was 91%. The overall true-positive, true-negative, false-negative, and failure rates of the biopsy were 100% (19/19) 100% (2/2), 0% (0/23), and 9% (2/23). The median total procedure time from the skin puncture to the needle in the target was 30 sec (from 5–60 s). Lesion depth and localizations, operator experience, in-plane or out-of-plane approach did not affect significantly the technical, diagnostic success, or procedure time. Even when the tumor size decreased, the procedure time did not increase. Conclusions: Electromagnetic-tracked biopsy is accurate to
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Katsumi, Hidemasa; Tanaka, Yutaro; Hitomi, Kaori; Liu, Shu; Quan, Ying-Shu; Kamiyama, Fumio; Sakane, Toshiyasu; Yamamoto, Akira
2017-08-17
To improve the transdermal bioavailability and safety of alendronate (ALN), a nitrogen-containing bisphosphonate, we developed self-dissolving microneedle arrays (MNs), in which ALN is loaded only at the tip portion of micron-scale needles by a dip-coating method (ALN(TIP)-MN). We observed micron-scale pores in rat skin just after application of ALN(TIP)-MN, indicating that transdermal pathways for ALN were created by MN. ALN was rapidly released from the tip of MNs as observed in an in vitro release study. The tip portions of MNs completely dissolved in the rat skin within 5 min after application in vivo. After application of ALN(TIP)-MN in mice, the plasma concentration of ALN rapidly increased, and the bioavailability of ALN was approximately 96%. In addition, the decrease in growth plate was effectively suppressed by this efficient delivery of ALN in a rat model of osteoporosis. Furthermore, no skin irritation was observed after application of ALN(TIP)-MN and subcutaneous injection of ALN, while mild skin irritation was induced by whole-ALN-loaded MN (ALN-MN)-in which ALN is contained in the whole of the micron-scale needles fabricated from hyaluronic acid-and intradermal injection of ALN. These findings indicate that ALN(TIP)-MN is a promising transdermal formulation for the treatment of osteoporosis without skin irritation.
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Directory of Open Access Journals (Sweden)
Omar Masabni
2017-01-01
Full Text Available Purpose. The aim of the study was to locate the infraorbital foramen (IOF in relation to the infraorbital margin (IOM for proper injections of local anesthetics in skull specimens. Another aim was to determine the depth of needle penetration into pterygopalatine fossa through the greater palatine canal (GPC. Materials and Methods. 102 skull halves were used to measure the distances between (1 IOF and IOM and (2 IOF and alveolar ridge of maxilla at second premolar. Needles were inserted and bent at a 45° angle, passing through the GPC at the level of hard palate. The depth of the tip of needle emerging out of GPC into pterygopalatine fossa was measured. Results. The mean distance between IOF and IOM was 6.46±1.57 mm on the right side and 6.74±1.72 mm on the left. The mean distance between IOF and alveolar bone process of the maxilla at second premolar was 29.07±3.58 mm on the right side and 29.39±3.78 mm on the left. The mean depth of penetration of the needle into the pterygopalatine fossa was similar on both sides. Conclusions. Proper identification of IOF and pterygopalatine fossa is of great significance during local anesthesia injections, due to their close proximity to vital anatomic structures.
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Song, Y G; Byun, J H; Hwang, S Y; Kim, C W; Shim, S G
2015-08-01
Central venous catheter (CVC) placement plays an important role in clinical practice; however, optimal positioning of the CVC tip remains a controversial issue. The objective of this study was to evaluate the use of vertebral body unit (VBUs), to locate the cavoatrial junction (CAJ), for optimal CVC tip placement based on chest radiography (CXR) using the carina as a landmark. 524 patients who underwent coronary computed tomographic angiography (CTA) and CXR were included. The position of the CAJ was identified using VBUs, and the efficacy of VBUs for locating the CAJ with the carina as a landmark was analysed using multiple regression analysis. A VBU was defined as the distance between two adjacent vertebral bodies, including the inter-vertebral disk space. The mean (sd) distance from the carina to the superior CAJ was 54.3 (9.7) mm on CTA; the mean distance in VBUs at the level of the carina was 21.4 (1.7) mm on CTA and 22.6 (2.1) mm on CXR. The mean CAJ position was 2.5 VBUs below the carina on CTA and 2.4 VBUs below on CXR with 95% limits of agreement between -0.6 and +0.3. The position of the CVC tip in relation to the carina can be described using the thoracic spine as an internal ruler, and the position of the CAJ in adults was reliably estimated to be 2.4 VBUs below the carina. KCT0001319. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Modeling, simulation, and optimal initiation planning for needle insertion into the liver.
Sharifi Sedeh, R; Ahmadian, M T; Janabi-Sharifi, F
2010-04-01
Needle insertion simulation and planning systems (SPSs) will play an important role in diminishing inappropriate insertions into soft tissues and resultant complications. Difficulties in SPS development are due in large part to the computational requirements of the extensive calculations in finite element (FE) models of tissue. For clinical feasibility, the computational speed of SPSs must be improved. At the same time, a realistic model of tissue properties that reflects large and velocity-dependent deformations must be employed. The purpose of this study is to address the aforementioned difficulties by presenting a cost-effective SPS platform for needle insertions into the liver. The study was constrained to planar (2D) cases, but can be extended to 3D insertions. To accommodate large and velocity-dependent deformations, a hyperviscoelastic model was devised to produce an FE model of liver tissue. Material constants were identified by a genetic algorithm applied to the experimental results of unconfined compressions of bovine liver. The approach for SPS involves B-spline interpolations of sample data generated from the FE model of liver. Two interpolation-based models are introduced to approximate puncture times and to approximate the coordinates of FE model nodes interacting with the needle tip as a function of the needle initiation pose; the latter was also a function of postpuncture time. A real-time simulation framework is provided, and its computational benefit is highlighted by comparing its performance with the FE method. A planning algorithm for optimal needle initiation was designed, and its effectiveness was evaluated by analyzing its accuracy in reaching a random set of targets at different resolutions of sampled data using the FE model. The proposed simulation framework can easily surpass haptic rates (>500 Hz), even with a high pose resolution level ( approximately 30). The computational time required to update the coordinates of the node at the
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Rossa, Carlos; Lehmann, Thomas; Sloboda, Ronald; Usmani, Nawaid; Tavakoli, Mahdi
2017-08-01
Global modelling has traditionally been the approach taken to estimate needle deflection in soft tissue. In this paper, we propose a new method based on local data-driven modelling of needle deflection. External measurement of needle-tissue interactions is collected from several insertions in ex vivo tissue to form a cloud of data. Inputs to the system are the needle insertion depth, axial rotations, and the forces and torques measured at the needle base by a force sensor. When a new insertion is performed, the just-in-time learning method estimates the model outputs given the current inputs to the needle-tissue system and the historical database. The query is compared to every observation in the database and is given weights according to some similarity criteria. Only a subset of historical data that is most relevant to the query is selected and a local linear model is fit to the selected points to estimate the query output. The model outputs the 3D deflection of the needle tip and the needle insertion force. The proposed approach is validated in ex vivo multilayered biological tissue in different needle insertion scenarios. Experimental results in five different case studies indicate an accuracy in predicting needle deflection of 0.81 and 1.24 mm in the horizontal and vertical lanes, respectively, and an accuracy of 0.5 N in predicting the needle insertion force over 216 needle insertions.
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[Learning experience of acupuncture technique from professor ZHANG Jin].
Xue, Hongsheng; Zhang, Jin
2017-08-12
As a famous acupuncturist in the world, professor ZHANG Jin believes the key of acupuncture technique is the use of force, and the understanding of the "concentrating the force into needle body" is essential to understand the essence of acupuncture technique. With deep study of Huangdi Neijing ( The Inner Canon of Huangdi ) and Zhenjiu Dacheng ( Compendium of Acupuncture and Moxibustion ), the author further learned professor ZHANG Jin 's theory and operation specification of "concentrating force into needle body, so the force arriving before and together with needle". The whole-body force should be subtly focused on the tip of needle, and gentle force at tip of needle could get significant reinforcing and reducing effect. In addition, proper timing at tip of needle could start reinforcing and reducing effect, lead qi to disease location, and achieve superior clinical efficacy.
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Possibilities of the chemical analysis of Scots pine (Pinus sylvestris) needles
International Nuclear Information System (INIS)
Viksna, A.
1999-01-01
Scots pine (Pinus sylvestris L.) is a good bio indicator. This species is widely distributed in Europe, including Latvia, is easily identified, and is used in bio indication studies. It is known that the concentrations of most elements in needles change with time. These changes are connected to the processes involved in the uptake, transportation, storage and retranslocation of the elements. Scots pine keeps their needles for several years (3 to 4 years) and are suitable for the study of time related processes. The chemical composition of pine needles is used for the study the deposition and impact of air pollutants. Coniferous needles are covered with epicuticular wax, which act as a trap for airborne deposits. A comparison of chemical composition of pine needles that were unwashed and washed with chloroform made it possible to distinguish which elements were on the needles and to evaluate the character of pollution. The most important stage of the analysis of pine needles is sampling. Nutrient concentrations in the needles of coniferous trees have been shown to vary with the needle age and tree age, the phase of the annual physiological cycle, availability of nutrients in the soil and needle position within the crown. It is very important to take representative sample for the analysis. In the current work the trace element concentrations of the single needle were analysed by electrothermal atomic absorption spectrometry (ETAAS) and total reflection X-ray spectrometry (TXRF). The results of analysis showed that concentration of some elements depends from the position of needle within branch for the same needle age class. The concentrations of trace elements in the single needles within main shoot were more or less constant compare with other order shoots at given needle age class. Some higher variations in the elemental concentrations between single needles were observed in the tip part of main shoot. The actual distribution of the elements within a needle has
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Drug-related deaths and the sales of needles through pharmacies.
Davidson, Peter J; Martinez, Alexis; Lutnick, Alexandra; Kral, Alex H; Bluthenthal, Ricky N
2015-02-01
Providing needles to people who inject drugs is a well-proven public health response to the transmission of HIV and other blood borne viruses. Despite over a quarter of a century of research, new concerns about potential unintended negative consequences of needle distribution continue to emerge. Specifically, a claim was recently made that the introduction of pharmacy sales of needles was followed by an increase in overdoses in pharmacy parking lots. If true, this would have serious implications for the design of needle access programs, particularly those involving pharmacy sales of needles. We examine spatial relationships between drug-related deaths and pharmacies in Los Angeles County (population 9.8 million) before and after the 2007 enactment of a California law allowing pharmacy sales of needles without a prescription. Seven thousand and forty-nine drugs related deaths occurred in Los Angeles county from 2000 to 2009 inclusive. Four thousand two hundred and seventy-five of these deaths could be geocoded, and were found to be clustered at the census tract level. We used three methods to examine spatial relationships between overdose death locations and pharmacy locations for two years on either side of the enactment of the pharmacy sales law, and found no statistically significant changes. Among the 711 geocodable deaths occurring in the two years following the change in law, no death was found to occur within 50m of a pharmacy which sold needles. These results are consistent with prior studies which suggest pharmacy sales of needles improve access to needles without causing increased harms to the surrounding community. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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The keys to successful TIPS in patients with portal vein thrombosis and cavernous transformation.
Lombardo, S; Espejo, J J; Pérez-Montilla, M E; Zurera, L J; González-Galilea, Á
Portal vein thrombosis is a common complication in patients with cirrhosis. Anticoagulation involves a high risk of bleeding secondary to portal hypertension, so placing transjugular intrahepatic portosystemic shunts (TIPS) has become an alternative treatment for portal vein thrombosis. Three strategies for TIPS placement have been reported: 1) portal recanalization and conventional implantation of the TIPS through the jugular vein; 2) portal recanalization through percutaneous transhepatic/transsplenic) access; and (3) insertion of the TIPS between the suprahepatic vein and a periportal collateral vessel without portal recanalization. We describe different materials that can be used as fluoroscopic targets for the TIPS needle and for portal recanalization. This article aims to show the success of TIPS implantation using different combinations of the techniques listed above, which is a good treatment alternative in these patients whose clinical condition makes them difficult to manage, and to show that portal vein thrombosis/cavernous transformation should not be considered a contraindication for TIPS. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.
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[Sheng's acupuncture manipulation at bone-nearby acupoints and the academic thoughts].
Sheng, Ji-li; Jin, Xiao-qing
2014-11-01
Sheng's acupuncture manipulation at bone-nearby acupoints is a set of needling manipulation of the chief physician of TCM, SHENG Xie-sun, summarized through his over 50 years clinical experiences and on the basis of Internal Classic. Regarding this manipulation, on the premise of acupoint selection based on syndrome differentiation, the acupoints close to bone are possibly selected and punctured, with the needle tip toward bone edge, and followed by the technique to achieve reducing purpose. Clinically, the significant immediate analgesia can be achieved in pain disorders such as headache and toothache. Professor Sheng thought, corresponding to the location of needle insertion and needling depth, the tissue layers of needle tip passing through should be considered specially. The site of needle insertion should be changeable so as to ensure the needle tip reaching the bone. This manipulation for analgesia provides a certain guide for acupuncture study, especially for the mechanism study on acupuncture analgesia.
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Spruce needles used as radioecological biotracers
International Nuclear Information System (INIS)
Seidel, C.; Gruber, V.; Baumgartner, A.
2009-01-01
In a two years project spruce needle samples of the Austrian Bioindicator Grid were analysed by gamma-ray spectrometry to investigate the spatial and temporal distribution of radionuclides in spruce needles of the last 25 years with the main focus on the radioactive contamination before and after the Chernobyl fallout 1986. More than 600 spruce needle samples at selected locations of the Bioindicator Grid were analysed for different natural and anthropogenic radionuclides: 137 Cs, 40 K, 210 Pb, 226 Ra, 228 Ra, 238 U. Additionally, soil samples were taken at selected sites to study the soil-to-plant transfer. This radioecological evaluation is an important part of an existing environmental surveillance programme in Upper Austria in order to gain basic information on the impact of environmental changes on the radioecological behaviour of spruce trees. (orig.)
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LES of cavitating flow inside a Diesel injector including dynamic needle movement
Örley, F.; Hickel, S.; Schmidt, S. J.; Adams, N. A.
2015-12-01
We perform large-eddy simulations (LES) of the turbulent, cavitating flow inside a 9-hole solenoid common-rail injector including jet injection into gas during a full injection cycle. The liquid fuel, vapor, and gas phases are modelled by a homogeneous mixture approach. The cavitation model is based on a thermodynamic equilibrium assumption. The geometry of the injector is represented on a Cartesian grid by a conservative cut-element immersed boundary method. The strategy allows for the simulation of complex, moving geometries with sub-cell resolution. We evaluate the effects of needle movement on the cavitation characteristics in the needle seat and tip region during opening and closing of the injector. Moreover, we study the effect of cavitation inside the injector nozzles on primary jet break-up.
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Energy Technology Data Exchange (ETDEWEB)
Ogawa, H; Matsui, Y; Kimura, S [Nissan Motor Co. Ltd. Tokyo (Japan)
1997-10-01
To reduce the exhaust emissions and fuel consumption of direct-injection diesel engines, it is essential to optimize the fuel injection equipment closely related to combustion and emission characteristics. In this study, three-dimensional computation has been applied to investigate the effects of the injection nozzle specifications (e.g., sac volume, round shape at the inlet of the nozzle hole) and needle tip deviation on internal flow characteristics. The computational results revealed that the effects of the nozzle specifications and needle tip deviation with a smaller needle lift on internal flow characteristics and a general approach to optimize the injection nozzle specifications were obtained. 3 refs., 10 figs., 1 tab.
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Patients’ Knowledge of and Practices Relating to the Disposal of Used Insulin Needles
Directory of Open Access Journals (Sweden)
Kerri T. Musselman, PharmD
2010-01-01
Full Text Available Objective: To determine (1 how patients currently dispose of used insulin needles, (2 whether patients were educated about disposal of their used insulin needles, and (3 who educated patients about the disposal of their used insulin needles.Methods: A self-administered questionnaire was designed for this study. The survey assessed patient knowledge about disposal of used insulin needles and the patient-reported source and location of education about disposal techniques. The questionnaire was administered to a convenience sample of patients from four locations in Richmond, Virginia. Any patient who used insulin, was at least 18 years old, and was willing to complete the survey was eligible for inclusion.Results: Fifty responses were received with 40% indicating that education had been received on the disposal of used needles. From that 40%, nurses were identified as the source of education 60% of the time and pharmacists 25% of the time. Approximately 50% of the respondents reported disposing of used needles directly in the trash when at home. While away from home, 22% reported placing used needles in the trash, and 38% took them home for disposal.Conclusion: Patients are not consistently educated regarding the proper disposal of used needles. Health care practitioners should play a larger role in educating patients about the potential risks of inappropriate needle disposal and appropriate disposal methods. Future research is still needed to understand fully the magnitude of the problems associated with inappropriate needle disposal by patients.
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The Problem of Metal Needles in Acupuncture-fMRI Studies
Directory of Open Access Journals (Sweden)
Florian Beissner
2011-01-01
Full Text Available Acupuncture is a therapy based on sensory stimulation of the human body by means of metal needles. The exact underlying mechanisms of acupuncture have not been clarified so far. Functional magnetic resonance imaging (fMRI has become an important tool in acupuncture research. Standard acupuncture needles, which are made of ferromagnetic steel, however, are problematic in acupuncture-fMRI studies for several reasons, such as attraction by the scanner's magnetic field, significant image distortions and signal-dropouts, when positioned close to the head or even heating due to absorption of radio frequency (RF. The aim of this study was to compare two novel types of acupuncture needles with a standard needle for their effect on MRI image quality. The standard needle severely reduced image quality, when located inside the RF coil. The nonferromagnetic metal needle may pose a risk due to RF heating, while the plastic needle has a significantly larger diameter. In conclusion, our recommendations are: (1 standard needles should not be used in MRI; (2 Nonferromagnetic metal needles seem to be the best choice for acupoints outside of the transmitter coil; and (3 only plastic needles are suited for points inside the coil. Laser acupuncture may be a safe alternative, too.
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Bone biopsy needles. Mechanical properties, needle design and specimen quality
International Nuclear Information System (INIS)
Keulers, Annika; Penzkofer, T.; Cunha-Cruz, V.C.; Bruners, P.; Helmholtz Inst. fuer biomedizinische Technik, Aachen; Braunschweig, T.; Schmitz-Rode, T.; Mahnken, A.; Helmholtz Inst. fuer biomedizinische Technik, Aachen
2011-01-01
To quantitatively analyze differences in mechanical properties, needle design including signs of wear, subjective handling and specimen quality of bone biopsy needles. Materials and Methods: In this study 19 different bone biopsy systems (total 38; 2 /type) were examined. With each biopsy needle five consecutive samples were obtained from vertebral bodies of swine. During puncture a force-torques sensor measured the mechanical properties and subjective handling was assessed. Before and after each biopsy the needles were investigated using a profile projector and signs of wear were recorded. Afterwards, a pathologist semi-quantitatively examined the specimen regarding sample quality. The overall evaluation considered mechanical properties, needle wear, subjective handling and sample quality. Differences were assessed for statistical significance using ANOVA and t-test. Results: Needle diameter (p = 0.003) as well as needle design (p = 0.008) affect the mechanical properties significantly. Franseen design is significantly superior to other needle designs. Besides, length reduction recorded by the profile projector, as a quality criterion showed notable distinctions in between the needle designs. Conclusion: Bone biopsy needles vary significantly in performance. Needle design has an important influence on mechanical properties, handling and specimen quality. Detailed knowledge of those parameters would improve selecting the appropriate bone biopsy needle. (orig.)
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Chan, Edwin; Maa, Yuh-Fun; Overcashier, David; Hsu, Chung C
2011-01-01
This study is to investigate the effect of headspace air pressure in pre-filled syringes on liquid leak (dripping) from the syringe needle upon needle shield removal. Drip tests to measure drip quantity were performed on syringes manually filled with 0.5 or 1.0 mL of various aqueous solutions. Parameters assessed included temperature (filling and test), bulk storage conditions (tank pressure and the type of the pressurized gas), solution composition (pure water, 0.9% sodium chloride, and a monoclonal antibody formulation), and testing procedures. A headspace pressure analyzer was used to verify the drip test method. Results suggested that leakage is indeed caused by headspace pressure increase, and the temperature effect (ideal gas expansion) is a major, but not the only, factor. The dissolved gases in the liquid bulk prior to or during filling may contribute to leakage, as these gases could be released into the headspace due to solubility changes (in response to test temperature and pressure conditions) and cause pressure increase. Needle shield removal procedures were found to cause dripping, but liquid composition played little role. Overall, paying attention to the processing history (pressure and temperature) of the liquid bulk is the key to minimize leakage. The headspace pressure could be reduced by decreasing liquid bulk storage pressure, filling at a higher temperature, or employing lower solubility gas (e.g., helium) for bulk transfer and storage. Leakage could also be mitigated by simply holding the syringe needle pointing upward during needle shield removal. Substantial advances in pre-filled syringe technology development, particularly in syringe filling accuracy, have been made. However, there are factors, as subtle as how the needle shield (or tip cap) is removed, that may affect dosing accuracy. We recently found that upon removal of the tip cap from a syringe held vertically with needle pointed downwards, a small amount of solution, up to 3-4% of
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Energy Technology Data Exchange (ETDEWEB)
Moy, Charles K.S., E-mail: charles.moy@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Ranzi, Gianluca [ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Petersen, Timothy C. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia)
2011-05-15
One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation. -- Research highlights: {yields} We use electrostatic principles and finite element to model field-induced stresses. {yields} We study two-dimensional idealized needle-shaped field emitters. {yields} Stress distribution of hyperbolic, parabolic and sphere-on-orthogonal-cone tips mapped. {yields} Electron tomography to obtain the morphology of three-dimensional aluminium tips. {yields} Studies of the morphology of the porous tip demonstrate a fragile specimen.
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Dickenson, Nicholas E; Arizmendi, Olivia; Patil, Mrinalini K; Toth, Ronald T; Middaugh, C Russell; Picking, William D; Picking, Wendy L
2013-12-10
The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri , providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. The type III secretion apparatus (T3SA) is composed of a basal body, external needle, and regulatory tip complex. The nascent needle is a polymer of MxiH capped by a pentamer of invasion plasmid antigen D (IpaD). Exposure to bile salts (e.g., deoxycholate) causes a conformational change in IpaD and promotes recruitment of IpaB to the needle tip. It has been proposed that IpaB senses contact with host cell membranes, recruiting IpaC and inducing full secretion of T3SS effectors. Although the steps of T3SA maturation and their external triggers have been identified, details of specific protein interactions and mechanisms have remained difficult to study because of the hydrophobic nature of the IpaB and IpaC translocator proteins. Here, we explored the ability for a series of soluble N-terminal IpaB peptides to interact with IpaD. We found that DOC is required for the interaction and that a region of IpaB between residues 11-27 is required for maximum binding, which was confirmed in vivo. Furthermore, intramolecular FRET measurements indicated that movement of the IpaD distal domain away from the protein core accompanied the binding of IpaB11-226. Together, these new findings provide important new insight into the interactions and potential mechanisms that define the maturation of the Shigella T3SA needle tip complex and provide a foundation for further studies probing T3SS activation.
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Li, Pan; Yang, Zhiyong; Jiang, Shan
2018-06-01
Image-guided robot-assisted minimally invasive surgery is an important medicine procedure used for biopsy or local target therapy. In order to reach the target region not accessible using traditional techniques, long and thin flexible needles are inserted into the soft tissue which has large deformation and nonlinear characteristics. However, the detection results and therapeutic effect are directly influenced by the targeting accuracy of needle steering. For this reason, the needle-tissue interactive mechanism, path planning, and steering control are investigated in this review by searching literatures in the last 10 years, which results in a comprehensive overview of the existing techniques with the main accomplishments, limitations, and recommendations. Through comprehensive analyses, surgical simulation for insertion into multi-layer inhomogeneous tissue is verified as a primary and propositional aspect to be explored, which accurately predicts the nonlinear needle deflection and tissue deformation. Investigation of the path planning of flexible needles is recommended to an anatomical or a deformable environment which has characteristics of the tissue deformation. Nonholonomic modeling combined with duty-cycled spinning for needle steering, which tracks the tip position in real time and compensates for the deviation error, is recommended as a future research focus in the steering control in anatomical and deformable environments. Graphical abstract a Insertion force when the needle is inserted into soft tissue. b Needle deflection model when the needle is inserted into soft tissue [68]. c Path planning in anatomical environments [92]. d Duty-cycled spinning incorporated in nonholonomic needle steering [64].
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Cannula Versus Sharp Needle for Placement of Soft Tissue Fillers: An Observational Cadaver Study.
van Loghem, Jani A J; Humzah, Dalvi; Kerscher, Martina
2017-12-13
Soft-tissue fillers have become important products for facial rejuvenation. Deep fat compartments and facial bones lose volume during the natural aging process. For the most natural-looking results, deep volumetric injections at strategic sites are therefore preferred. Supraperiosteal placement is performed with a sharp needle or a non-traumatic cannula. The primary objective was to determine whether there is a difference in precision between supraperiosteal placement with a sharp needle compared with a non-traumatic cannula in cadaver specimens. A secondary objective was to analyze the safety profiles of both injection techniques. Cadaver heads were injected with dye material and soft-tissue fillers at multiple aesthetic facial sites on the supraperiosteum and subsequently dissected for observation of dye and filler placement. The non-traumatic cannula technique resulted in product being confined to the deep anatomic layers. In contrast, with the sharp needle technique, material was placed in multiple anatomic layers, from the periosteum to more superficial skin layers. For both techniques results were consistent for all facial sites. Although direct extrapolation from cadavers to the in vivo situation cannot be made, cannulae showed more precision in placement of product. With the sharp needle, the material was injected on the periosteum, and then migrated in a retrograde direction along the trajectory of the needle path, ending up in multiple anatomic layers. The sharp needle technique also showed a higher complication risk with intra-arterial injection occurring, even though the needle tip was positioned on the periosteum and the product was injected with the needle in constant contact with the periosteum. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com
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Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.
2015-01-01
Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 degrees is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.
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Needle Decompression in Appalachia Do Obese Patients Need Longer Needles?
Directory of Open Access Journals (Sweden)
Carter, Thomas Edward
2013-11-01
Full Text Available Introduction: Needle decompression of a tension pneumothorax can be a lifesaving procedure. It requires an adequate needle length to reach the chest wall to rapidly remove air. With adult obesity exceeding one third of the United States population in 2010, we sought to evaluate the proper catheter length that may result in a successful needle decompression procedure. Advance Trauma Life Support (ATLS currently recommends a 51 millimeter (mm needle, while the needles stocked in our emergency department are 46 mm. Given the obesity rates of our patient population, we hypothesize these needles would not have a tolerable success rate of 90%. Methods: We retrospectively reviewed 91 patient records that had computed tomography of the chest and measured the chest wall depth at the second intercostal space bilaterally. Results: We found that 46 mm needles would only be successful in 52.7% of our patient population, yet the ATLS recommended length of 51 mm has a success rate of 64.8%. Therefore, using a 64 mm needle would be successful in 79% percent of our patient population. Conclusion: Use of longer length needles for needle thoracostomy is essential given the extent of the nation’s adult obesity population. [West J Emerg Med. 2013;14(6:650-652.
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The longitudinal distribution of elements in developing and aging scots pine needles
International Nuclear Information System (INIS)
Viksna, A.; Helmisaari, H.S.; Standzenieks, P.; Lindgren, E.S.
2001-01-01
Needle or leaf nutrient concentrations are commonly used for analysing tree nutritional status for e.g. estimating possible nutrient deficiencies or unbalances. The practise used e.g. in northern Europe is to sample needles during the dormant period from either the current or in some cases several needle age classes from a fixed position of a number of trees in a stand. The sampled needles are then dried and ground for nutrient analysis. The sampling aims to minimise the spatial and temporal variation in needle nutrient concentrations for estimating the availability of nutrients in soil through needle analysis. It is well known that the concentrations of different nutrients vary in needles with the phase of the annual physiological cycle (Fife and Nambiar 1982, 1984), needle age (Florence and Chuoung 1974, Madgwick et al. 1983) and sampling position (Helmisaari 1992). The samples analysed are usually bulk samples of a large number of needles, and the results are mean concentrations representing an age class in a stand. There is little information on how different needles vary in nutrient concentrations, and even less on how nutrient concentrations vary within individual needles. The import and export of elements to and from needles varies according to the developmental phase of needles, and is likely to affect the element concentrations in different parts of the needles. Accordingly, the elemental concentrations measured in different parts of the needles may give an insight into the transport pattern of an element and its potential mobility. Up to now, very few studies report needle element concentrations in different parts of the needles, e.g. tip, base and middle (Giertych et al. 1997), or in different parts of the leaf phloem (Eschrich et al. 1988). The aim of this study was to determine the distribution of different elements along the length of single Scots pine needles of different age and during different stages of needle physiological cycle. The scanning
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Does a paresthesia during spinal needle insertion indicate intrathecal needle placement?
Pong, Ryan P; Gmelch, Benjamin S; Bernards, Christopher M
2009-01-01
Paresthesias are relatively common during spinal needle insertion, however, the clinical significance of the paresthesia is unknown. A paresthesia may result from needle-to-nerve contact with a spinal nerve in the epidural space, or, with far lateral needle placement, may result from contact with a spinal nerve within the intervertebral foramen. However, it is also possible and perhaps more likely, that paresthesias occur when the spinal needle contacts a spinal nerve root within the subarachnoid space. This study was designed to test this latter hypothesis. Patients (n = 104) scheduled for surgery under spinal anesthesia were observed during spinal needle insertion. If a paresthesia occurred, the needle was fixed in place and the stylet removed to observe whether cerebrospinal fluid (CSF) flowed from the hub. The presence of CSF was considered proof that the needle had entered the subarachnoid space. Paresthesias occurred in 14/103 (13.6%) of patients; 1 patient experienced a paresthesia twice. All paresthesias were transient. Following a paresthesia, CSF was observed in the needle hub 86.7% (13/15) of the time. Our data suggest that the majority of transient paresthesias occur when the spinal needle enters the subarachnoid space and contacts a spinal nerve root. Therefore, when transient paresthesias occur during spinal needle placement it is appropriate to stop and assess for the presence of CSF in the needle hub, rather than withdraw and redirect the spinal needle away from the side of the paresthesia as some authors have suggested.
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Rutigliano, Sandra; Abraham, John A; Kenneally, Barry E; Zoga, Adam C; Nevalainen, Mika; Roedl, Johannes B
Percutaneous computed tomography (CT)-guided needle biopsy has proven to be an efficacious method for sampling of many soft tissue lesions, especially deep-seated masses in the abdomen and pelvis. This study sought to test the potential for a novel steerable needle to improve localization and to reduce procedure duration and radiation dose compared with a conventional straight needle. A fresh, raw meat sample (lean bovine flank) was imbedded with cylindrical radiopaque and radiolucent obstacles designed to simulate vessels (radiolucent objects) and bones (radiopaque objects) on CT. A pit-containing olive (partially radiopaque) was imbedded beyond the obstacles to represent the target. Two sites on the surface of the meat were selected and marked to determine initial needle placement. Two radiologists with different levels of experience proceeded to position a straight needle and the steerable needle from each skin site to the target using CT guidance as efficiently as possible, avoiding the obstacles. The total positioning time, the number of CT scans required for positioning, and the number of repositioning events (partial withdrawal followed by advancement) were tracked for the straight and steerable needles. For the straight needle, total time to reach the target was 499 to 667 seconds (mean, 592 seconds); for the steerable needle, total time to reach the target was 281 to 343 seconds (mean, 309 seconds), on average, 48% lower. The number of CT scans needed for needle positioning averaged 6.25 for the straight needle and 3.5 for the steerable needle, which is 44% lower. Repositioning events (withdrawing and readvancing the needle) ranged from 3 to 10 for the straight needle (mean, 6.5) and 0 for the steerable needle. Using an in vitro model embedded with obstacles, the steerable needle performed better than a straight needle with regard to procedure time, needle repositioning events, and CT scans required for placement.
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Comparison of design features and mechanical properties of commercially available Veress needles.
Schramel, Johannes P; Kindslehner, Angelika; Bockstahler, Barbara A; Dupré, Gilles P
2017-10-01
To compare design features and mechanical properties of 13 commercially available Veress needles (VN). In vitro biomechanical study. Veress needles from 9 manufacturers (6 reusable, 6 disposable, and 1 with a reusable stylet combined with a disposable cannula) were included in the study. Veress needles are designed with a spring-loaded stylet to protect the tip of the cannula following insertion into the abdomen. Stylet forces were measured with a scale in a test jig by moving the stylet in 0.5 mm steps into the hollow cannula. Forces and spring rates were derived from force-displacement plots. Mass, mechanical dimensions, and the bevel angle and geometry were assessed. Differences between VN models were analyzed with a univariate analysis of variance. Results are reported as mean ± SD or median (range). Physical and mechanical parameters differed between models. The exposed stylet length was 3.5 mm (2-7). Three bevel geometries (bias, lancet type, and back-cut) with angles between 20° and 40° were identified. Reusable VN weigh more (24.9 ± 2.2 g) than disposable designs (6.0 ± 2.3 g). The mean values for the spring rate and the residual stylet force were 0.23 ± 0.08 Nmm -1 and 0.94 ± 0.28 N, respectively. The mean force required to move the stylet to the cannula tip was 1.81 ± 0.29 N and 2.77 ± 0.54 N to move to the proximal end of the bevel. Commercially available VN use diverse bevel geometries and have different mechanical characteristics. Studies investigating laparoscopic entry complications should explicitly report the type of VN model used. © 2017 The American College of Veterinary Surgeons.
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Energy Technology Data Exchange (ETDEWEB)
Kickuth, R.; Reichling, C.; Bley, T.; Hahn, D.; Ritter, C. [University Hospital of Wuerzburg (Germany). Inst. of Diagnostic and Interventional Radiology
2015-07-15
To evaluate the feasibility and efficacy of C-arm fluoroscopic cone-beam computed tomography (CACT) in combination with a new electromagnetic tracking (EMT) system for needle guidance during percutaneous biopsies. 53 patients were referred for biopsy of thoracic (n = 19) and abdominal (n = 34) lesions. CT-like images of the anatomical region of interest (ROI) were generated using a flat panel-based angiographic system. These images were transmitted to an EMT system. A coaxial puncture needle with a sensor in its tip was connected with the navigation system and tracked into an electromagnetic field created via a field generator. Data generated within this field were merged with the CACT images. On a monitor both the anatomical ROI and needle tip position were displayed to enable precise needle insertion into the target. Through the coaxial needle, biopsy specimens for the histologic evaluation were extracted. Number of representative biopsy samples, number of core biopsies/patient, total procedure time, dose-area product, fluoroscopic time, and complications were recorded. 53 CACT/EMT-guided biopsy procedures were performed, 48 of which (91 %) yielded representative tissue samples. Four core biopsies were obtained from each patient. 40 (75 %) lesions were malignant and 13 (25 %) lesions were benign. The total procedure time was 9 ± 5 min (range, 3 - 23 min), fluoroscopic time was 0.8 ± 0.4 min (range, 0.4 - 2 min). The mean dose-area product (cGy cm{sup 2}) was 7373 (range, 895 - 26 904). The rate of complications (1 pneumothorax, 2 hemoptyses) was 6 %. CACT combined with EMT appears to be a feasible and effective technique for the guidance of percutaneous biopsies with a low rate of therapeutically relevant complications.
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International Nuclear Information System (INIS)
Kickuth, R.; Reichling, C.; Bley, T.; Hahn, D.; Ritter, C.
2015-01-01
To evaluate the feasibility and efficacy of C-arm fluoroscopic cone-beam computed tomography (CACT) in combination with a new electromagnetic tracking (EMT) system for needle guidance during percutaneous biopsies. 53 patients were referred for biopsy of thoracic (n = 19) and abdominal (n = 34) lesions. CT-like images of the anatomical region of interest (ROI) were generated using a flat panel-based angiographic system. These images were transmitted to an EMT system. A coaxial puncture needle with a sensor in its tip was connected with the navigation system and tracked into an electromagnetic field created via a field generator. Data generated within this field were merged with the CACT images. On a monitor both the anatomical ROI and needle tip position were displayed to enable precise needle insertion into the target. Through the coaxial needle, biopsy specimens for the histologic evaluation were extracted. Number of representative biopsy samples, number of core biopsies/patient, total procedure time, dose-area product, fluoroscopic time, and complications were recorded. 53 CACT/EMT-guided biopsy procedures were performed, 48 of which (91 %) yielded representative tissue samples. Four core biopsies were obtained from each patient. 40 (75 %) lesions were malignant and 13 (25 %) lesions were benign. The total procedure time was 9 ± 5 min (range, 3 - 23 min), fluoroscopic time was 0.8 ± 0.4 min (range, 0.4 - 2 min). The mean dose-area product (cGy cm 2 ) was 7373 (range, 895 - 26 904). The rate of complications (1 pneumothorax, 2 hemoptyses) was 6 %. CACT combined with EMT appears to be a feasible and effective technique for the guidance of percutaneous biopsies with a low rate of therapeutically relevant complications.
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Use of a Puncture Needle for Recanalization of an Occluded Right Subclavian Vein
International Nuclear Information System (INIS)
Gupta, Himanshu; Murphy, Timothy P.; Soares, Gregory M.
1998-01-01
We report a patient in whom we used a puncture needle to initiate percutaneous recanalization of a chronic occlusion of the junction between the right subclavian vein and the right brachiocephalic vein. Under fluoroscopic guidance, an 18-gauge needle was used to puncture the right subclavian vein. When contrast material injected through the needle confirmed intravascular location, the needle was advanced until it deflected and perforated an occlusion balloon target positioned within the right brachiocephalic vein. This technique may be useful in patients with central venous occlusions that are refractory to traversal using traditional catheter and guidewire techniques
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Yamaguchi, Satoshi; Tsutsui, Kihei; Satake, Koji; Morikawa, Shigehiro; Shirai, Yoshiaki; Tanaka, Hiromi T
2014-10-01
Our goal was to develop a three-dimensional finite element model that enables dynamic analysis of needle insertion for soft materials. To demonstrate large deformation and fracture, we used the arbitrary Lagrangian-Eulerian (ALE) method for fluid analysis. We performed ALE-based finite element analysis for 3% agar gel and three types of copper needle with bevel tips. To evaluate simulation results, we compared the needle deflection and insertion force with corresponding experimental results acquired with a uniaxial manipulator. We studied the shear stress distribution of agar gel on various time scales. For 30°, 45°, and 60°, differences in deflections of each needle between both sets of results were 2.424, 2.981, and 3.737mm, respectively. For the insertion force, there was no significant difference for mismatching area error (p<0.05) between simulation and experimental results. Our results have the potential to be a stepping stone to develop pre-operative surgical planning to estimate an optimal needle insertion path for MR image-guided microwave coagulation therapy and for analyzing large deformation and fracture in biological tissues. Copyright © 2014 Elsevier Ltd. All rights reserved.
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25-gauge fibered-needle for label-free fluorescence analysis of breast masses: a first in vivo study
Toullec, Alexis; Mathieu, Marie-Christine; Benoit, Charlotte; Farcy, René; Tourasse, Christophe; Boisserie-Lacroix, Martine; Fontaine-Aupart, Marie-Pierre; Delaloge, Suzette; Balleyguier, Corinne
2018-02-01
Breast lesions diagnosis and characterization need additional cost-effective techniques to avoid unnecessary invasive procedures, such as core needle biopsies, in the case of benign tumors. Endogenous fluorescence is an effective method to highlight in situ metabolic and/or structural changes between cancerous and non-cancerous lesions. In this context, we developed an original set-up, consisting of a 405 nm laser diode transmitting light through a 25 Gauge (0.45 mm x 50mm) 14° sharp fibered needle to excite intranodular fluorophores around the needle tip and providing real-time labelfree fluorescence spectral analysis of lesions from 450 nm to 650 nm. The objective was to help radiologists to classify suspicious masses in vivo and in real-time within the lesion. We reported the results of spectral differences between 14 invasive lobular carcinomas and 6 intraductal papilloma enrolled in a clinical study.
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Dickenson, Nicholas E.; Arizmendi, Olivia; Patil, Mrinalini K.; Toth, Ronald T.; Middaugh, C. Russell; Picking, William D.; Picking, Wendy L.
2014-01-01
The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri, providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. The type III secretion apparatus (T3SA) is comprised of a basal body, external needle, and regulatory tip complex. The nascent needle is a polymer of MxiH capped by a pentamer of invasion plasmid antigen D (IpaD). Exposure to bile salts (e.g. deoxycholate) causes a conformational change in IpaD and promotes recruitment of IpaB to the needle tip. It has been proposed that IpaB senses contact with host cell membranes, recruiting IpaC and inducing full secretion of T3SS effectors. While the steps of T3SA maturation and their external triggers have been identified, details of specific protein interactions and mechanisms have remained difficult to study due to the hydrophobic nature of the IpaB and IpaC translocator proteins. Here we explored the ability for a series of soluble N-terminal IpaB peptides to interact with IpaD. We found that DOC is required for the interaction and that a region of IpaB between residues 11–27 is required for maximum binding, which was confirmed in vivo. Furthermore, intramolecular FRET measurements indicated that movement of the IpaD distal domain away from the protein core accompanied the binding of IpaB11-226. Together these new findings provide important new insight into the interactions and potential mechanisms that define the maturation of the Shigella T3SA needle tip complex and provide a foundation for further studies probing T3SS activation. PMID:24236510
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Menacé, Cécilia; Choquet, Olivier; Abbal, Bertrand; Bringuier, Sophie; Capdevila, Xavier
2017-04-01
The real-time ultrasound-guided paramedian sagittal oblique approach for neuraxial blockade is technically demanding. Innovative technologies have been developed to improve nerve identification and the accuracy of needle placement. The aim of this study was to evaluate three types of ultrasound scans during ultrasound-guided epidural lumbar punctures in a spine phantom. Eleven sets of 20 ultrasound-guided epidural punctures were performed with 2D, GPS, and multiplanar ultrasound machines (660 punctures) on a spine phantom using an in-plane approach. For all punctures, execution time, number of attempts, bone contacts, and needle redirections were noted by an independent physician. Operator comfort and visibility of the needle (tip and shaft) were measured using a numerical scale. The use of GPS significantly decreased the number of punctures, needle repositionings, and bone contacts. Comfort of the physician was also significantly improved with the GPS system compared with the 2D and multiplanar systems. With the multiplanar system, the procedure was not facilitated and execution time was longer compared with 2D imaging after Bonferroni correction but interaction between the type of ultrasound system and mean execution time was not significant in a linear mixed model. There were no significant differences regarding needle tip and shaft visibility between the systems. Multiplanar and GPS needle-tracking systems do not reduce execution time compared with 2D imaging using a real-time ultrasound-guided paramedian sagittal oblique approach in spine phantoms. The GPS needle-tracking system can improve performance in terms of operator comfort, the number of attempts, needle redirections and bone contacts. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Rusnan, Fara Naila; Mohamad, Khairul Anuar; Seria, Dzul Fahmi Mohd Husin; Saad, Ismail; Ghosh, Bablu K.; Alias, Afishah [Nano Engineering & Materials (NEMs) Research Group, Faculty of Engineering Universiti Malaysia Sabah, Kota Kinabalu 88400 Sabah (Malaysia)
2015-08-28
3,16-bis triisopropylsilylethynyl (Pentacene) (TIPS-Pentacene) compactable interface property is important in order to have a good arrangement of molecular structure. Comparison for TIPS-Pentacene deposited between two different surface layers conducted. 0.1wt% TIPS-Pentacene diluted in chloroform were deposited onto poly(methylmeaclyrate) (PMMA) layered transparent substrates using slide coating method. X-ray diffraction (XRD) used to determine crystallinity of thin films. Series of (00l) diffraction peaks obtained with sharp first peaks (001) for TIPS-Pentacene deposited onto PMMA layer at 5.35° and separation of 16.3 Å. Morphology and surface roughness were carried out using scanning electron microscope (SEM) and surface profilemeter LS500, respectively.TIPS-Pentacene deposited onto PMMA layer formed needled-like-shape grains with 10.26 nm surface roughness. These properties were related as thin film formed and its surface roughness plays important role towards good mobility devices.
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[Discussion on needling sensation, arrival of qi and needling response (Deqi)].
Zhang, Fang; Wang, Hong-Du
2012-12-01
The current appointed teaching material of Science of Acupuncture and Moxibustion holds that there is no difference among the needling sensation, arrival of qi and needling response. However, the author has a different understanding. Therefore, Neijing (Internal Classic), its annotation, exposition and understandings of ancient and modern famous experts are cited to analyze their meanings. And the result indicates that the needling sensation is subjective feelings and perceived responses of doctors and patients. Arrival of qi is the healing process of the organ through activating the anti-pathogenic qi to expel the pathogens. The needling response is the final aim of acupuncture therapy. Thus, the meaning of needling sensation, arrival of qi, and needling response are different. And an accurate understanding can better guide acupuncture treatment.
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International Nuclear Information System (INIS)
Klõšeiko, J.
2003-01-01
The fraction of photosynthetically active radiation transmitted through the canopy (FPAR) on a forested dune was measured at different locations with a ceptometer, and the correlations of carbohydrates in Scots pine needles with FPAR were studied. The hypothesis was that the sucrose content is relatively stable in different light environments and the main effect of the location on the dune is expressed on the glucose content in needles assuming that glucose regulates the balance between the light environment and nutritional conditions influencing the carbohydrate production and demand processes in trees. The contents of the investigated carbohydrates did not correlate with the FPAR, which was significantly elevated at the higher locations on the dune (500 per cent on top) relative to the locations on the foot. The concentrations of hexoses varied substantially between the individual branches or trees from the same plots and between plots, while sucrose levels on single plots were relatively constant. Analysis of variance indicated the effect of the location on the concentrations of sucrose and excess bound fructose, and on the total content of carbohydrates in current-year needles in which the investigated parameters were positively correlated with the respective parameters in one-year-old needles. The results indicate that the content of carbohydrates does not directly depend on the light environment on the dune, though the large variance in the content of hexoses possibly requires increasing the number of samples on each plot to reveal the differences in needles between the locations on the dune
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International Nuclear Information System (INIS)
Lamppu, Jukka; Huttunen, Satu
2003-01-01
Deceased needle longevity was related to increased heavy metal concentrations. - Scots pine (Pinus sylvestris L.) shoots were sampled along transects near one urban pollution source and two smelters. Needle Mg, P and K concentrations decreased from the second to the fourth age class linearly with needle survival along the urban pollution gradient. Still, over 80% of the average concentration of these nutrients remained in the fourth needle age class. Decreased needle longevity was closely related to the increased heavy metal concentrations near the smelters. Near the urban pollution source, it was related to the increased annual needle mass and the increased needle nutrient concentrations. Decreased Mn accumulation along with needle age was detected near all pollution sources. Leaching of Mn from needles and especially from soil as a cause of decreased needle concentrations is discussed
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DEFF Research Database (Denmark)
Beleggia, Marco; Kasama, Takeshi; Larson, D. J.
2014-01-01
We apply off-axis electron holography and Lorentz microscopy in the transmission electron microscope to map the electric field generated by a sharp biased metallic tip. A combination of experimental data and modelling provides quantitative information about the potential and the field around...... the tip. Close to the tip apex, we measure a maximum field intensity of 82 MV/m, corresponding to a field k factor of 2.5, in excellent agreement with theory. In order to verify the validity of the measurements, we use the inferred charge density distribution in the tip region to generate simulated phase...
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Study of geographical trends of polycyclic aromatic hydrocarbons using pine needles
Amigo, José Manuel; Ratola, Nuno; Alves, Arminda
2011-10-01
In this work, pine needles were used as polycyclic aromatic hydrocarbons (PAHs) markers to study the PAHs distribution over several geographical locations in Portugal and over time. Four pine needle sampling campaigns (winter, spring, summer and autumn 2007) were carried out in 29 sites, covering the major urban centres, some industrial points, smaller cities, rural areas and remote locations. Needles from Pinus pinaster Ait. and Pinus pinea L. trees were collected from 2005 and 2006 shoots, corresponding to one up to three years of exposure. Spatial trends of the incidence of PAHs indicate an increase from the remote to the urban and industrial sites. The mean values for the sum of 16 PAHs ranged from 96 ± 30 ng g -1 (dry weight) for remote sites to 866 ± 304 ng g -1 (dw) for industrial sites for P. pinaster needles and from 188 ± 117 ng g -1 (dw) for rural sites to 337 ± 153 ng g -1 (dw) for urban sites for P. pinea. Geographic information system tools and principal component analysis revealed that the contamination patterns of PAHs are somehow related to several socio-geographic parameters of the sampling sites. The geographical trend for the PAHs is similar between seasons in terms of PAH levels, but some diverse behaviour is found on the separation of lighter and heavier PAHs. Differences between P. pinaster and P. pinea needles are stronger in terms of PAH uptake loads than in the site type fingerprints.
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Needle segmentation using 3D Hough transform in 3D TRUS guided prostate transperineal therapy
Energy Technology Data Exchange (ETDEWEB)
Qiu Wu [Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario N6A 5K8 (Canada); Yuchi Ming; Ding Mingyue [Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Tessier, David; Fenster, Aaron [Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada)
2013-04-15
Purpose: Prostate adenocarcinoma is the most common noncutaneous malignancy in American men with over 200 000 new cases diagnosed each year. Prostate interventional therapy, such as cryotherapy and brachytherapy, is an effective treatment for prostate cancer. Its success relies on the correct needle implant position. This paper proposes a robust and efficient needle segmentation method, which acts as an aid to localize the needle in three-dimensional (3D) transrectal ultrasound (TRUS) guided prostate therapy. Methods: The procedure of locating the needle in a 3D TRUS image is a three-step process. First, the original 3D ultrasound image containing a needle is cropped; the cropped image is then converted to a binary format based on its histogram. Second, a 3D Hough transform based needle segmentation method is applied to the 3D binary image in order to locate the needle axis. The position of the needle endpoint is finally determined by an optimal threshold based analysis of the intensity probability distribution. The overall efficiency is improved through implementing a coarse-fine searching strategy. The proposed method was validated in tissue-mimicking agar phantoms, chicken breast phantoms, and 3D TRUS patient images from prostate brachytherapy and cryotherapy procedures by comparison to the manual segmentation. The robustness of the proposed approach was tested by means of varying parameters such as needle insertion angle, needle insertion length, binarization threshold level, and cropping size. Results: The validation results indicate that the proposed Hough transform based method is accurate and robust, with an achieved endpoint localization accuracy of 0.5 mm for agar phantom images, 0.7 mm for chicken breast phantom images, and 1 mm for in vivo patient cryotherapy and brachytherapy images. The mean execution time of needle segmentation algorithm was 2 s for a 3D TRUS image with size of 264 Multiplication-Sign 376 Multiplication-Sign 630 voxels. Conclusions
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Needle segmentation using 3D Hough transform in 3D TRUS guided prostate transperineal therapy
International Nuclear Information System (INIS)
Qiu Wu; Yuchi Ming; Ding Mingyue; Tessier, David; Fenster, Aaron
2013-01-01
Purpose: Prostate adenocarcinoma is the most common noncutaneous malignancy in American men with over 200 000 new cases diagnosed each year. Prostate interventional therapy, such as cryotherapy and brachytherapy, is an effective treatment for prostate cancer. Its success relies on the correct needle implant position. This paper proposes a robust and efficient needle segmentation method, which acts as an aid to localize the needle in three-dimensional (3D) transrectal ultrasound (TRUS) guided prostate therapy. Methods: The procedure of locating the needle in a 3D TRUS image is a three-step process. First, the original 3D ultrasound image containing a needle is cropped; the cropped image is then converted to a binary format based on its histogram. Second, a 3D Hough transform based needle segmentation method is applied to the 3D binary image in order to locate the needle axis. The position of the needle endpoint is finally determined by an optimal threshold based analysis of the intensity probability distribution. The overall efficiency is improved through implementing a coarse-fine searching strategy. The proposed method was validated in tissue-mimicking agar phantoms, chicken breast phantoms, and 3D TRUS patient images from prostate brachytherapy and cryotherapy procedures by comparison to the manual segmentation. The robustness of the proposed approach was tested by means of varying parameters such as needle insertion angle, needle insertion length, binarization threshold level, and cropping size. Results: The validation results indicate that the proposed Hough transform based method is accurate and robust, with an achieved endpoint localization accuracy of 0.5 mm for agar phantom images, 0.7 mm for chicken breast phantom images, and 1 mm for in vivo patient cryotherapy and brachytherapy images. The mean execution time of needle segmentation algorithm was 2 s for a 3D TRUS image with size of 264 × 376 × 630 voxels. Conclusions: The proposed needle segmentation
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...
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Directory of Open Access Journals (Sweden)
Jean-Philippe Demers
2013-03-01
Full Text Available The Type Three Secretion System (T3SS, or injectisome, is a macromolecular infection machinery present in many pathogenic Gram-negative bacteria. It consists of a basal body, anchored in both bacterial membranes, and a hollow needle through which effector proteins are delivered into the target host cell. Two different architectures of the T3SS needle have been previously proposed. First, an atomic model of the Salmonella typhimurium needle was generated from solid-state NMR data. The needle subunit protein, PrgI, comprises a rigid-extended N-terminal segment and a helix-loop-helix motif with the N-terminus located on the outside face of the needle. Second, a model of the Shigella flexneri needle was generated from a high-resolution 7.7-Å cryo-electron microscopy density map. The subunit protein, MxiH, contains an N-terminal α-helix, a loop, another α-helix, a 14-residue-long β-hairpin (Q51-Q64 and a C-terminal α-helix, with the N-terminus facing inward to the lumen of the needle. In the current study, we carried out solid-state NMR measurements of wild-type Shigella flexneri needles polymerized in vitro and identified the following secondary structure elements for MxiH: a rigid-extended N-terminal segment (S2-T11, an α-helix (L12-A38, a loop (E39-P44 and a C-terminal α-helix (Q45-R83. Using immunogold labeling in vitro and in vivo on functional needles, we located the N-terminus of MxiH subunits on the exterior of the assembly, consistent with evolutionary sequence conservation patterns and mutagenesis data. We generated a homology model of Shigella flexneri needles compatible with both experimental data: the MxiH solid-state NMR chemical shifts and the state-of-the-art cryoEM density map. These results corroborate the solid-state NMR structure previously solved for Salmonella typhimurium PrgI needles and establish that Shigella flexneri and Salmonella typhimurium subunit proteins adopt a conserved structure and orientation in their
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McAllister, Devin V.; Wang, Ping M.; Davis, Shawn P.; Park, Jung-Hwan; Canatella, Paul J.; Allen, Mark G.; Prausnitz, Mark R.
2003-11-01
Arrays of micrometer-scale needles could be used to deliver drugs, proteins, and particles across skin in a minimally invasive manner. We therefore developed microfabrication techniques for silicon, metal, and biodegradable polymer microneedle arrays having solid and hollow bores with tapered and beveled tips and feature sizes from 1 to 1,000 μm. When solid microneedles were used, skin permeability was increased in vitro by orders of magnitude for macromolecules and particles up to 50 nm in radius. Intracellular delivery of molecules into viable cells was also achieved with high efficiency. Hollow microneedles permitted flow of microliter quantities into skin in vivo, including microinjection of insulin to reduce blood glucose levels in diabetic rats. transdermal drug delivery | skin | microelectromechanical systems | solid microneedle | hollow needle injection
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The optical "Veress-needle"--initial puncture with a minioptic.
Schaller, G; Kuenkel, M; Manegold, B C
1995-02-01
Laparoscopic access is a necessary part of minimally invasive surgery. The double blind puncture with Veress-needle and trocar can cause lethal complications such as bowel injury, bleeding and gas-embolisation. Some authors have reported alternative techniques for laparoscopic abdominal access. Because no blind procedure can absolutely prevent injury, permanent visual control of perforated tissue layers as in open surgery should be achieved to prevent possible injury at an early stage. Previously described procedures could not fulfil all requirements to comply with this ideal, i.e. permanent visual control of abdominal wall penetration prior to establishment of pneumoperitoneum and trocar insertion without further possible damage. We designed a 2 mm fibreglass optic 250 mm in length that is inserted into a suitable cannula. Special construction allows rinsing through the cannula to clear the vision and to open spaces in the puncture track by water dissection. After incision of the skin, all layers of the abdominal wall can be visualised, including blood vessels and internal surfaces. Once the abdominal cavity is reached, the needle tip is retracted and a two-step dilation allows the trocar to be introduced via the puncture track. Only then does insufflation begin. The fibreglass optic-equipped safety needle was used for visually controlled access in 184 laparoscopic surgical procedures. After a period of training, all layers of the abdominal wall could be recognised exactly. In two patients with dense adhesions, perforation of the small bowel was diagnosed immediately by endoscopic viewing. The small injury needed no treatment, and the intended procedure was completed laparoscopically.(ABSTRACT TRUNCATED AT 250 WORDS)
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Loyeung, Bertrand Y. K.; Cobbin, Deirdre M.
2013-01-01
Introduction. In traditional Chinese acupuncture, needle sensation (deqi) is purported to contribute to a therapeutic outcome. While researchers have attempted to define deqi qualitatively, few have examined the effects of needling parameters on its intensity. Methods. 24 healthy subjects completed eight interventions scheduled at least one week apart, which involved manual acupuncture to LI4 or a designated nonacupoint (NAP) on the hand, with real or simulated manipulation each three minutes and needle retentions of one or 21 minutes. Intensities of needling sensation and pain were reported every three minutes and sensation qualities were reported post-intervention. Results. Immediately after needle insertion, similar levels of mean needle sensation and of pain were reported independent of intervention. At subsequent measurement times, only two interventions (one at LI4 and one at NAP) maintained statistically significantly elevated needle sensation and pain scores and reported higher numbers of needle sensation descriptors. For both, the needle was retained for 21 minutes and manipulated every three minutes. Neither intervention differed significantly in terms of levels of pain, and needle sensation or numbers and qualities of needle sensation described. Conclusion. In this group of healthy subjects, the initial needling for all eight interventions elicited similar levels of needle sensation and pain. These levels were only maintained if there was ongoing of needle manipulation and retention of the needle. By contrast, the strength of needle sensation or pain experienced was independent of insertion site. PMID:24159337
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International Nuclear Information System (INIS)
Chiba, Wataru; Sawai, Satoru; Ishida, Hisao; Hanawa, Takeshi; Matsubara, Yoshito; Ikeda, Sadao; Kinoshita, Moritoshi; Ikei, Nobuhiro.
1993-01-01
Of 140 cases of mediastinal neoplasms in our hospital, histological diagnosis was confirmed in 129 cases. We examined the methods of preoperative biopsy with those 129 cases. Biopsy had been performed in 25 cases. Mediastinoscopy was performed in seven cases, needle biopsy in eight cases, lymph node biopsy in eight cases, esophageal biopsy using a gastrofiberscope in one case, transbronchial biopsy using a bronchoscope in one case. The true positive rates of those methods were 100% for both mediastinoscopy and lymph node biopsy, and 75% for needle biopsy. Preoperative misdiagnosis occurred in two cases of needle biopsy. The postoperative histological diagnosis was malignant lymphoma in both cases. We performed gene analysis of the immunoglobulin heavy chain gene, light chain κ and λ genes, and the T-cell receptor β gene by use of biopsied specimens, and we found rearrangement bands of these genes in the cases of malignant lymphoma. Therefore, we summarize that gene analysis is a reliable method if malignant lymphoma is suspected. If a needle biopsy is performed under CT guidance, the needle is sure to puncture the tumor. We concluded, therefore, that if a tumor is located in the anterior mediastinum, CT-guided needle biopsy should be performed first of all. Mediastinoscopy is a useful method if the tumor is located in the mid-mediastinum. (author)
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Effect of needle tract bleeding on occurrence of pneumothorax after transthoracic needle biopsy
International Nuclear Information System (INIS)
Topal, U.; Berkman, Yahya M.
2005-01-01
Purpose: Occasionally bleeding along the needle trajectory is observed at post-biopsy computed tomographic sections. This study was designed to evaluate the possible effect of needle tract bleeding on the occurrence of pneumothorax and on requirement of chest tube insertion. Materials and methods: Two hundred eighty-four needle biopsies performed in 275 patients in whom the needle traversed the aerated lung parenchyma were retrospectively reviewed. Bleeding along the needle tract, occurrence of pneumothorax and need for chest tube insertion, type and size of the needle, size of the lesion, length of the lung traversed by the needle, presence or absence of emphysema were noted. Effect of these factors on the rate of pneumothorax and needle-tract bleeding was evaluated. The data were analyzed by χ 2 test. Results: Pneumothorax developed in 100 (35%) out of 284 procedures requiring chest tube placement in 16 (16%). Variables that were significantly associated with an increased risk of pneumothorax were depth of the lesion (P 0.05). However, analysis of the relation between length of lung traversed by the needle, tract-bleeding and pneumothorax rate indicated that tract-bleeding had a preventive effect on development of pneumothorax (P 0.05). Conclusion: Bleeding in the needle tract has a preventive effect on the occurrence of the pneumothorax in deep-seated lesions and in the presence of emphysema, although it does not affect the overall rate of pneumothorax
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Directory of Open Access Journals (Sweden)
In Hye Song
2015-03-01
Full Text Available Background: Core needle biopsy is a relatively new technique used to diagnose salivary gland lesions, and its role in comparison with fine needle aspiration cytology needs to be refined. Methods: We compared the results of 228 ultrasound-guided core needle biopsy and 371 fine needle aspiration procedures performed on major salivary gland tumors with their postoperative histological diagnoses. Results: Core needle biopsy resulted in significantly higher sensitivity and more accurate tumor subtyping, especially for malignant tumors, than fine needle aspiration. No patient developed major complications after core needle biopsy. Conclusions: We recommend ultrasoundguided core needle biopsy as the primary diagnostic tool for the preoperative evaluation of patients with salivary gland lesions, especially when malignancy is suspected.
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Oliveira-Santos, Thiago; Klaeser, Bernd; Weitzel, Thilo; Krause, Thomas; Nolte, Lutz-Peter; Peterhans, Matthias; Weber, Stefan
2011-01-01
Percutaneous needle intervention based on PET/CT images is effective, but exposes the patient to unnecessary radiation due to the increased number of CT scans required. Computer assisted intervention can reduce the number of scans, but requires handling, matching and visualization of two different datasets. While one dataset is used for target definition according to metabolism, the other is used for instrument guidance according to anatomical structures. No navigation systems capable of handling such data and performing PET/CT image-based procedures while following clinically approved protocols for oncologic percutaneous interventions are available. The need for such systems is emphasized in scenarios where the target can be located in different types of tissue such as bone and soft tissue. These two tissues require different clinical protocols for puncturing and may therefore give rise to different problems during the navigated intervention. Studies comparing the performance of navigated needle interventions targeting lesions located in these two types of tissue are not often found in the literature. Hence, this paper presents an optical navigation system for percutaneous needle interventions based on PET/CT images. The system provides viewers for guiding the physician to the target with real-time visualization of PET/CT datasets, and is able to handle targets located in both bone and soft tissue. The navigation system and the required clinical workflow were designed taking into consideration clinical protocols and requirements, and the system is thus operable by a single person, even during transition to the sterile phase. Both the system and the workflow were evaluated in an initial set of experiments simulating 41 lesions (23 located in bone tissue and 18 in soft tissue) in swine cadavers. We also measured and decomposed the overall system error into distinct error sources, which allowed for the identification of particularities involved in the process as well
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Anderson, T. Anthony; Kang, Jeon Woong; Gubin, Tatyana; Dasari, Ramachandra R.; So, Peter T. C.
2016-01-01
BACKGROUND Neuraxial anesthesia and epidural steroid injection techniques require precise anatomical targeting to ensure successful and safe analgesia. Previous studies suggest that only some of the tissues encountered during these procedures can be identified by spectroscopic methods, and no previous study has investigated the use of Raman, diffuse reflectance, and fluorescence spectroscopies. The authors hypothesized that real-time needle-tip spectroscopy may aid epidural needle placement and tested the ability of spectroscopy to distinguish each of the tissues in the path of neuraxial needles. METHODS For comparison of detection methods, the spectra of individual, dissected ex vivo paravertebral and neuraxial porcine tissues were collected using Raman spectroscopy (RS), diffuse reflectance spectroscopy (DRS), and fluorescence spectroscopy (FS). Real-time spectral guidance was tested using a 2 mm inner diameter fiber optic probe-in-needle device. Raman spectra were collected during the needle’s passage through intact paravertebral and neuraxial porcine tissue and analyzed afterward. The RS tissue signatures were verified as mapping to individual tissue layers using histochemical staining and widefield microscopy. RESULTS Raman spectroscopy revealed a unique spectrum for all ex vivo paravertebral and neuraxial tissue layers; DRS and FS spectra were not distinct for all tissues. Moreover, when accounting for the expected order of tissues, real-time Raman spectra recorded during needle insertion also permitted identification of each paravertebral and neuraxial porcine tissue. CONCLUSIONS This study demonstrates Raman spectroscopy can distinguish the tissues encountered during epidural needle insertion. This technology may prove useful during needle placement by providing evidence of its anatomical localization. PMID:27466032
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Lai, Yu-Chi; Choy, Young Bin; Haemmerich, Dieter; Vorperian, Vicken R; Webster, John G
2004-10-01
Finite element method (FEM) analysis has become a common method to analyze the lesion formation during temperature-controlled radiofrequency (RF) cardiac ablation. We present a process of FEM modeling a system including blood, myocardium, and an ablation catheter with a thermistor embedded at the tip. The simulation used a simple proportional-integral (PI) controller to control the entire process operated in temperature-controlled mode. Several factors affect the lesion size such as target temperature, blood flow rate, and application time. We simulated the time response of RF ablation at different locations by using different target temperatures. The applied sites were divided into two groups each with a different convective heat transfer coefficient. The first group was high-flow such as the atrioventricular (AV) node and the atrial aspect of the AV annulus, and the other was low-flow such as beneath the valve or inside the coronary sinus. Results showed the change of lesion depth and lesion width with time, under different conditions. We collected data for all conditions and used it to create a database. We implemented a user-interface, the lesion size estimator, where the user enters set temperature and location. Based on the database, the software estimated lesion dimensions during different applied durations. This software could be used as a first-step predictor to help the electrophysiologist choose treatment parameters.
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Improved transvenous liver biopsy needle
DEFF Research Database (Denmark)
Henriksen, Jens Henrik Sahl; Matzen, P; Christoffersen, P
1979-01-01
A modified type of the standard transvenous cholangiography biopsy needle is described. The modified tranvenous liver biopsy needle caused only minimal artefactual changes of the liver biopsy specimens. The new type of biopsy needle is a modified Menghini needle. The conventional Menghini needle...... should be avoided for transvenous catheter biopsies because of risk of leaving catheter fragments in the liver....
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Characterization of metal-coated fiber tip for NSOM lithography by tip-to-tip scan
International Nuclear Information System (INIS)
Kubicova, I.; Pudis, D.; Suslik, L.; Skriniarova, J.
2011-01-01
For the optical field characterization, a tip-to-tip scan of two metal-coated fiber tips with circular aperture at the apex was performed. The optical field irradiated from the fiber probe in illumination mode was analyzed by NSOM represented by fiber probe in collection mode. The near-field intensity profile of the source fiber tip in the plane perpendicular to the axis of the tip was taken. Experimental stage requires high resolution 3D motion system controlled by computer (Fig. 1). The source and the detector fiber tip were placed on the moving and static part of the 3D nanoposition system, respectively. As a light source, a modulated 473 nm DPSS laser was used. After the source fiber tip characterization, the NSOM lithography was performed. In the experimental setup from Fig. 1, the detector fiber tip was replaced by a sample fixed in a vacuum holder. As a sample, a 600 nm positive photoresist AZ 5214E was spin-coated on a GaAs substrate. Exposure was carried out by irradiation of the sample at desired positions through the fiber tip aperture. The sample was developed in AZ 400K developer for 30 s and rinsed in DI water. A promising tip-to-tip scanning technique for characterization of metal-coated fiber tips with aperture at the apex was presented. Nearly-circular aperture shapes were documented from NSOM measurements with diameter estimated to be less than 460 nm. By knowing the source-detector distance and the FWHM of the near-field intensity profile, the tip-to-tip scan proves an easy and fast method to analyze the fiber tip aperture properties. The fiber tip resolution was confirmed by preparation of 2D planar structures in thin photoresist layer, where the NSOM lithography uses the metal-coated fiber tip characterized in previous section. (authors)
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De Diego, N; Rodríguez, J L; Dodd, I C; Pérez-Alfocea, F; Moncaleán, P; Lacuesta, M
2013-05-01
Anatomical, physiological and phytohormonal changes involved in drought tolerance were examined in different Pinus radiata D. Don breeds subjected to soil drying and rewatering. Breeds with the smallest stomatal chamber size had the lowest transpiration rate and the highest intrinsic water-use efficiency. Xylem cell size was positively correlated with leaf hydraulic conductance and needle indole-3-acetic acid (IAA) concentrations, whereas transpiration rate was negatively correlated with needle abscisic acid (ABA) levels. Since these two phytohormones seem important in regulating the P. radiata drought response, they were simultaneously immunolocalized in roots and needles of the most tolerant breed (P. radiata var. radiata × var. cedrosensis) during two sequential drought cycles and after rewatering. During drought, IAA was unequally distributed into the pointed area of the needle cross-section and mainly located in mesophyll and vascular tissue cells of needles, possibly inducing needle epinasty, whereas ABA was principally located in guard cells, presumably to elicit stomata closure. In the roots, at the end of the first drought cycle, while strong IAA accumulation was observed in the cortex, ABA levels decreased probably due to translocation to the leaves. Rewatering modified the distribution of both IAA and ABA in the needles, causing an accumulation principally in vascular tissue, with residual concentrations in mesophyll, likely favouring the acclimatization of the plants for further drought cycles. Contrarily, in the roots IAA and ABA were located in the exodermis, a natural barrier that regulates the phytohormone translocation to other plant tissues and hormone losses to the soil solution after rewatering. These results confirm that immunolocalization is an efficient tool to understand the translocation of IAA and ABA in plants subjected to different water stress situations, and clarify their role in regulating physiological responses such as stomata
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Energy Technology Data Exchange (ETDEWEB)
Schulz, Boris [Goethe University Hospital, Institute for Diagnostic and Interventional Radiology, Frankfurt (Germany); Goethe University Hospital, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Eichler, Katrin; Siebenhandl, Petra; Gruber-Rouh, Tatjana; Vogl, Thomas Josef; Zangos, Stephan [Goethe University Hospital, Institute for Diagnostic and Interventional Radiology, Frankfurt (Germany); Czerny, Christoph [Goethe University Hospital, Department of Trauma Surgery, Frankfurt (Germany)
2013-01-15
To analyse the feasibility and accuracy of robotic aided interventions on a phantom when using a modern C-arm-mounted cone beam computed tomography (CBCT) device in combination with needle guidance software. A small robotic device capable of holding and guiding needles was attached to the intervention table. After acquiring a 3D data set the access path was planned on the CBCT workstation and shown on the intervention monitor. Then the robot was aligned to the live fluoroscopic image. A total of 40 punctures were randomly conducted on a phantom armed with several targets (diameter 2 mm) in single and double oblique trajectory (n = 20 each). Target distance, needle deviation and time for the procedures were analysed. All phantom interventions (n = 40) could be performed successfully. Mean target access path within the phantom was 8.5 cm (min 4.2 cm, max 13.5 cm). Average needle tip deviation was 1.1 mm (min 0 mm, max 4.5 mm), time duration was 3:59 min (min 2:07 min, max 10:37 min). When using the proposed robot device in a CBCT intervention suite, highly accurate needle-based interventional punctures are possible in a reasonable timely manner in single as well as in double oblique trajectories. (orig.)
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International Nuclear Information System (INIS)
Schulz, Boris; Eichler, Katrin; Siebenhandl, Petra; Gruber-Rouh, Tatjana; Vogl, Thomas Josef; Zangos, Stephan; Czerny, Christoph
2013-01-01
To analyse the feasibility and accuracy of robotic aided interventions on a phantom when using a modern C-arm-mounted cone beam computed tomography (CBCT) device in combination with needle guidance software. A small robotic device capable of holding and guiding needles was attached to the intervention table. After acquiring a 3D data set the access path was planned on the CBCT workstation and shown on the intervention monitor. Then the robot was aligned to the live fluoroscopic image. A total of 40 punctures were randomly conducted on a phantom armed with several targets (diameter 2 mm) in single and double oblique trajectory (n = 20 each). Target distance, needle deviation and time for the procedures were analysed. All phantom interventions (n = 40) could be performed successfully. Mean target access path within the phantom was 8.5 cm (min 4.2 cm, max 13.5 cm). Average needle tip deviation was 1.1 mm (min 0 mm, max 4.5 mm), time duration was 3:59 min (min 2:07 min, max 10:37 min). When using the proposed robot device in a CBCT intervention suite, highly accurate needle-based interventional punctures are possible in a reasonable timely manner in single as well as in double oblique trajectories. (orig.)
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Giuliani, Michela; Rinaldi, Pierluigi; Rella, Rossella; Fabrizi, Gina; Petta, Federica; Carlino, Giorgio; Di Leone, Alba; Mulè, Antonino; Bufi, Enida; Romani, Maurizio; Belli, Paolo; Bonomo, Lorenzo
2017-11-01
The aim of the present study was to assess the diagnostic accuracy of ultrasound-guided core needle biopsy (US-CNB) of breast lesions, comparing smaller needles (16- and 18-gauge) with the 14-gauge needle, and to analyze the lesion characteristics influencing US-CNB diagnostic performance. All the patients provided informed consent before the biopsy procedure. The data from breast lesions that had undergone US-CNB in our institution from January 2011 to January 2015 were retrospectively reviewed. The inclusion criterion was the surgical histopathologic examination findings of the entire lesion or radiologic follow-up data for ≥ 24 months. The exclusion criterion was the use of preoperative neoadjuvant therapy. The US-CNB results were compared with the surgical pathologic results or with the follow-up findings in the 3 needle size groups (14-, 16-, and 18-gauge). The needle size- and lesion characteristic-specific diagnostic accuracy parameters were evaluated. Statistical analysis was performed using a dedicated software program, and P ≤ .01 was considered significant. A total of 1118 US-CNB cases (1042 patients) were included. Of the 1118 cases, 630 (56.3%) were in the 14-gauge group, 136 (12.2%) in the 16-gauge, and 352 (31.5%) in the 18-gauge needle group. Surgery was performed on 800 lesions (71.6%). Of these, 619 were malignant, 77 were high risk, and 104 were benign. The remaining 318 lesions (28.4%) underwent follow-up imaging studies. All the lesions were stable and, therefore, were considered benign. No differences were observed in the diagnostic accuracy parameters among the 3 needle size groups (P > .01). The false-negative rate was greater for lesions .01). US-CNB performed with small needles (16 and 18 gauge) had the same diagnostic accuracy as that performed with 14-gauge needles, regardless of the lesion characteristics. Copyright © 2017 Elsevier Inc. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Seidel, C.; Gruber, V.; Baumgartner, A. [BOKU - Univ. fuer Bodenkultur Wien (Austria). LLC-Labor Arsenal; Idinger, J. [Technische Univ. Wien (Austria). Atominst.; Fuerst, A. [BFW - Bundesforschungs- und Ausbildungszentrum fuer Wald, Naturgefahren und Landschaft, Wien (Austria). Inst. fuer Waldschutz, Pflanzenanalyse; Maringer, F.J. [BOKU - Univ. fuer Bodenkultur Wien (Austria). LLC-Labor Arsenal; BEV - Bundesamt fuer Eich- und Vermessungswesen, Wien (Austria)
2009-07-01
In a two years project spruce needle samples of the Austrian Bioindicator Grid were analysed by gamma-ray spectrometry to investigate the spatial and temporal distribution of radionuclides in spruce needles of the last 25 years with the main focus on the radioactive contamination before and after the Chernobyl fallout 1986. More than 600 spruce needle samples at selected locations of the Bioindicator Grid were analysed for different natural and anthropogenic radionuclides: {sup 137}Cs, {sup 40}K, {sup 210}Pb, {sup 226}Ra, {sup 228}Ra, {sup 238}U. Additionally, soil samples were taken at selected sites to study the soil-to-plant transfer. This radioecological evaluation is an important part of an existing environmental surveillance programme in Upper Austria in order to gain basic information on the impact of environmental changes on the radioecological behaviour of spruce trees. (orig.)
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International Nuclear Information System (INIS)
Watanabe, Kota; Matsumoto, Morio; Iizuka, Shingo
2008-01-01
The purpose of this study was to evaluate the efficacy of ball tip method for thoracic pedicle screw placements in idiopathic scoliosis patients. 24 patients with adolescent idiopathic scoliosis were included in this study. Conventional method was performed in 12 patients. Ball tip method was performed in 12 patients. Accuracy of the pedicle screw placement was evaluated based on the postoperative CT. In the ball tip method, a probe which was consisted of ball tip with flexible shaft was used. After removing of cortical bone at a starting point, the probe was inserted manually or sometimes with gently tapping by hammer. During the maneuver, the probe will gradually progress into cancellous bone in the pedicle, without perforating cortical bone in the pedicle. Following expansion of the hole by a rigid gear shift probe, screw was placed in the pedicle. 65.1% of screws were located within pedicle in the conventional group and 86.5% in the ball tip group. 5.3% of screws were located out of pedicle within 2 mm in the conventional group and 8.2% in the ball tip group. 15.8% of screws were located out of pedicle beyond 2 mm and 1.8% in the ball tip group. The ball tip method enhanced the accuracy of thoracic pedicle screw placements in adolescent idiopathic scoliosis patients. The ball tip method may be effective for accurate pedicle screw placement in patients with adolescent idiopathic scoliosis. (author)
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Masai, Kyohei; Sasada, Shinji; Izumo, Takehiro; Taniyama, Tomoko; Nakamura, Yukiko; Chavez, Christine; Sakurai, Hiroyuki; Tsuta, Koji; Tsuchida, Takaaki
2013-10-01
Desmoplastic malignant mesothelioma (DMM) is a rare subtype of malignant pleural mesothelioma (MPM) and is often difficult to distinguish from pleural fibrosis and reactive mesothelial hyperplasia, especially if the biopsy samples are small. We performed full-thickness pleural biopsy on a lesion suspected to be DMM using an insulated-tip diathermic knife-2 (IT knife-2) during flex-rigid pleuroscopy. IT knife-2 is a novel electrosurgical device for endoscopic submucosal dissection in the early gastrointestinal cancer. It consists of a needle knife with 3 short blades at the distal end attached to an insulated ceramic tip. A 54-year-old man presenting with chest wall mass and thickened pleura, in whom a computed tomography-guided percutaneous needle aspiration had remained negative, underwent flex-rigid pleuroscopy for definitive diagnosis. While applying electric current, we used the IT knife-2 to incise the pleura in a circular shape just above the endothoracic fascia. The incised pleura was removed by forceps and examined pathologically. The microscopic examination was compatible with DMM. We discovered that pleuroscopic punch biopsy using IT knife-2 can diagnose DMM. Use of IT knife-2 during flex-rigid pleuroscopy can obtain sufficient samples from densely thickened pleura, which is difficult to diagnose with small biopsies.
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Directory of Open Access Journals (Sweden)
Łabiszak Bartosz
2017-06-01
Full Text Available The main goal of this work was to examine interpopulational needle traits variability of Scots pine (Pinus sylvestris L. from four mountain, one foothill and three lowland, natural populations located in Poland. This choice of locations was motivated by the presumed different origins of mountainous populations and the necessity to demonstrate how closely they are related to lowland populations. Variation in the studied populations was determined using seven morphological traits of needles: 1 - needle length, 2 - number of stomatal rows on the flat side of a needle, 3 - number of stomata per 2 mm of needle length on the flat side, 4 - number of stomatal rows on the convex side of a needle, 5 - number of stomata per 2 mm of needle length on the convex side, 6 - number of serrations per 2 mm of the needle length on the left side and 7 - number of serrations per 2 mm of the needle length on the right side. Biometric data were analysed statistically, and it was found that (i needle traits differentiate studied populations; (ii the postulated division of the population into two groups is reflected in the obtained results; and (iii a particularly strong relationship was found between two relict pine populations from the Pieniny (Sokolica, Kazalnica, Czertezik and Tatra Mts. (Wielke Koryciska, which may be the result of the common origins and history of these two populations
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Needle-based polarization-sensitive OCT of breast tumor (Conference Presentation)
Villiger, Martin; Lorenser, Dirk; McLaughlin, Robert A.; Quirk, Bryden C.; Kirk, Rodney W.; Bouma, Brett E.; Sampson, David D.
2016-03-01
OCT imaging through miniature needle probes has extended the range of OCT and enabled structural imaging deep inside breast tissue, with the potential to assist in the intraoperative assessment of tumor margins. However, in many situations, scattering contrast alone is insufficient to clearly identify and delineate malignant areas. Here, we present a portable, depth-encoded polarization-sensitive OCT system, connected to a miniature needle probe. From the measured polarization states we constructed the tissue Mueller matrix at each sample location and improved the accuracy of the measured polarization states through incoherent averaging before retrieving the depth-resolved tissue birefringence. With the Mueller matrix at hand, additional polarization properties such as depolarization are readily available. We then imaged freshly excised breast tissue from a patient undergoing lumpectomy. The reconstructed local retardation highlighted regions of connective tissue, which exhibited birefringence due to the abundance of collagen fibers, and offered excellent contrast to areas of malignant tissue, which exhibited less birefringence due to their different tissue composition. Results were validated against co-located histology sections. The combination of needle-based imaging with the complementary contrast provided by polarization-sensitive analysis offers a powerful instrument for advanced tissue imaging and has potential to aid in the assessment of tumor margins during the resection of breast cancer.
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Method for locating a small magnetic object in the human body
Energy Technology Data Exchange (ETDEWEB)
Kaufman, L.; Williamson, S.J.; Ilmoniemi, R.J.; Weinberg, H.; Boyd, A.D.
1988-02-29
A piece of a thin acupuncture needle lodged under the right scapula of a patient could not be found in surgical procedures accompanied by studies of 30 standard x-ray images. To locate it, the authors mapped the magnetic-field component normal to a plane lying above the object, using a superconducting quantum interference device (SQUID). Assuming that the needle could be modeled as a magnetic dipole, the authors were able to infer its lateral position, depth, orientation, and magnetic moment. With this information, directed CT scans, high-resolution x-ray films, and the subsequent surgical removal of the needle proved that it could be located in the body with an accuracy of about three millimeters.
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International Nuclear Information System (INIS)
Jimenez Zuniga, Jorge Luis
2012-01-01
Guides have been made for the realization of breast biopsies through stereotaxy in the management of breast lesions. The type of injuries that have been detected in mammography services, most have corresponded to nonpalpable lesions, that should be clarified through the take samples for an histological study with the purpose of categorize them. A bibliographic review was realized of the findings most frequent in the breast pathology. Also, before a nonpalpable breast lesion that requires a diagnosis biopsy, should be assessed the method of suitable guide for to access the same. The interventionist procedures of the breast have been developed in last years and have been guided by stereotaxy, in order to preoperative localization of these lesions or for obtaining valid cytologic-histologic material to reach a diagnosis, as it has often been difficult to differentiate, just for the image, between benign and malignant lesions. Thus, has emerged the necessity to guide the needle tip objectifying the lesion through mammography. A localization system based on triangulation is applied. The location of the lesion is calculated in the three axes of space (X, Y and Z) with a minimum error. The stereotactic devices have created to guide needles to injuries from a unique projection. This has allowed that breast and lesion are subject on a site while have taken samples several times. The complete mammography study that include the projections craniocaudal (CC) and mediolateral oblique (MLO) are analyzed to find out exactly on which quadrant has found the injury. Sometimes, the injury only has observed in a unique projection which is used for locating. The two main devices that have been used to perform stereotactic biopsy are automatic gun of biopsy and vacuum-assisted directional biopsy. Automatic gun of biopsy has used a long needle tru-cut type, with calibers between 18 and 14, although it is preferred 14-gauge needles. Multiple samples obtained from this needle have
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Pinus nigra and Pinus pinaster needles as passive samplers of polycyclic aromatic hydrocarbons
International Nuclear Information System (INIS)
Piccardo, Maria Teresa; Pala, Mauro; Bonaccurso, Bruna; Stella, Anna; Redaelli, Anna; Paola, Gaudenzio; Valerio, Federico
2005-01-01
Nine polycyclic aromatic hydrocarbons (PAHs) were analysed in pine needles of different ages (from 6 to 30 months) collected from two species, Pinus nigra and Pinus pinaster, in seven sites located along a transect from a suburban to a rural area of Genoa (Italy). In all sites and for both species, concentrations of more volatile PAHs (phenanthrene, anthracene, fluoranthene, pyrene) were higher than those for other less volatile PAHs, which are preferentially sorbed to airborne particulates (benzo[a]anthracene, chrysene, benzofluoranthenes, benzo[a]pyrene). Concentrations of total PAHs found in P. nigra in the rural sites were, on the average, 2.3 times higher than those in P. pinaster growing nearby. In both pine species, concentrations of volatile PAHs increased according to needle age. Annual trends of other PAHs were more variable, with a general decrease in older needles. P. pinaster needles are shown to be more reliable passive samplers, since they are more resistant to plant diseases, and considerable variation in PAH concentration was observed in P. nigra needles with moulds and fungi. - The suitability of the pine needles as passive air samplers for persistent trace organics is demonstrated
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Pinus nigra and Pinus pinaster needles as passive samplers of polycyclic aromatic hydrocarbons
Energy Technology Data Exchange (ETDEWEB)
Piccardo, Maria Teresa [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy)]. E-mail: chimamb@istge.it; Pala, Mauro [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Bonaccurso, Bruna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Stella, Anna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Redaelli, Anna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Paola, Gaudenzio [Botany Department, Genoa University, C.so Dogali 1 canc., 16136 Genova (Italy); Valerio, Federico [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy)
2005-01-01
Nine polycyclic aromatic hydrocarbons (PAHs) were analysed in pine needles of different ages (from 6 to 30 months) collected from two species, Pinus nigra and Pinus pinaster, in seven sites located along a transect from a suburban to a rural area of Genoa (Italy). In all sites and for both species, concentrations of more volatile PAHs (phenanthrene, anthracene, fluoranthene, pyrene) were higher than those for other less volatile PAHs, which are preferentially sorbed to airborne particulates (benzo[a]anthracene, chrysene, benzofluoranthenes, benzo[a]pyrene). Concentrations of total PAHs found in P. nigra in the rural sites were, on the average, 2.3 times higher than those in P. pinaster growing nearby. In both pine species, concentrations of volatile PAHs increased according to needle age. Annual trends of other PAHs were more variable, with a general decrease in older needles. P. pinaster needles are shown to be more reliable passive samplers, since they are more resistant to plant diseases, and considerable variation in PAH concentration was observed in P. nigra needles with moulds and fungi. - The suitability of the pine needles as passive air samplers for persistent trace organics is demonstrated.
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Energy Technology Data Exchange (ETDEWEB)
Kim, Sang Yoon; Chung, Hye Won; Oh, Tack Sun; Lee, Jong Seok [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)
2017-04-15
Ultrasound-guided core needle biopsy (US-CNB) is an important step in the diagnosis of musculoskeletal soft-tissue lesions. To maximize efficacy and minimize the complications of US-CNB, it is critical to collaborate with a multidisciplinary team and to understand the particular considerations of US-CNB for these lesions. The purpose of this article is to provide a systematic review and step-by-step tips for using US-CNB to diagnose musculoskeletal soft-tissue lesions.
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Dynamics of translational friction in needle-tissue interaction during needle insertion.
Asadian, Ali; Patel, Rajni V; Kermani, Mehrdad R
2014-01-01
In this study, a distributed approach to account for dynamic friction during needle insertion in soft tissue is presented. As is well known, friction is a complex nonlinear phenomenon. It appears that classical or static models are unable to capture some of the observations made in systems subjected to significant frictional effects. In needle insertion, translational friction would be a matter of importance when the needle is very flexible, or a stop-and-rotate motion profile at low insertion velocities is implemented, and thus, the system is repeatedly transitioned from a pre-sliding to a sliding mode and vice versa. In order to characterize friction components, a distributed version of the LuGre model in the state-space representation is adopted. This method also facilitates estimating cutting force in an intra-operative manner. To evaluate the performance of the proposed family of friction models, experiments were conducted on homogeneous artificial phantoms and animal tissue. The results illustrate that our approach enables us to represent the main features of friction which is a major force component in needle-tissue interaction during needle-based interventions.
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Usefulness of sono-guided needle puncture for MR arthrography of the shoulder
International Nuclear Information System (INIS)
Choi, Jae Woong; Hong, Suk Ju; Suh, San Il; Yong, Hwan Suk; Kim, Jung Hyuk; Park, Cheol Min; Suh, Won Hyuck; Kim, Myung Gyu
2000-01-01
To evaluate the usefulness of sono-guided needle puncture for MR arthrography of the shoulder to locate the path of access and to control the correct placement of the needle into the shoulder. Fifteen patients with suspicion of shoulder pathology were included in this study. Patients were laid in supine positions with the arm extended and slightly abducted, the palm of the hand facing upward. A sonographic unit with a high resolution transducer with 7.5 MHz linear array was used. Axial images in the anterior aspect of the shoulder were obtained to localize the coracoid process and the anteromedical portion of the humerus. Using an aseptic technique, a 21-guage needle was advanced into the shoulder joint under ultrasonographic guidance. When the needle made contract with the articular cartilage of the humeral head, the needle was tiled to position is point in the articular cavity. Solution of 0.1 ml gadopentetate dimeglumine in 25 ml of normal saline was prepared and 12-16 ml was injected into the joint cavity. The intra-articular position of the needle and the compete distension of the shoulder joint were again confirmed by sonography. The needle was accurately placed in 14 out of 15 patients without damage to neighboring structures. It took 10 to 15 minutes to complete the procedure in 14 patients. No side effects attributable to gadopentetate dimeglumine were found. Sono-guided needle puncture for the shoulder MR arthrography can be a substitutable method for fluoroscopic guidance, with easy access, advantages of lacking radiation hazard and eliminating the need for iodized contrast agents.
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Needle phobia during pregnancy.
Searing, Kimberly; Baukus, Mary; Stark, Mary Ann; Morin, Karen H; Rudell, Barb
2006-01-01
The objective of this study was to understand the experience of a pregnant woman with needle phobia and examine its impact on her antepartum, intrapartum, and postpartum experience. A case study format was employed. A 21-year-old primiparous woman with diagnosed needle phobia was interviewed, and her prenatal and delivery records were reviewed. Three tasks during pregnancy were identified: seeking trusting relationships with health care providers; establishing and maintaining control and understanding; and coping with fear of needles, pain, and invasion. As frequent caregivers during childbearing, nurses with an understanding of needle phobia can help to establish trusting relationships with women with this phobia and support them and their families during childbearing and their encounters with needles. (c) 2006, AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses
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Yin, Tao; Ni, Jinxia; Zhu, Wenzeng
2015-10-01
To compare the effective differences between deep needling and shallow needling at three acupoints around ear for subjective tinnitus. Fifty patients with subjective tinnitus were randomized divided into a deep needling group and a shallow needling group, 25 cases in each group. Twenty-two patients in the deep needling group and 20 patients in the shallow needling group were brought into statistic in the end. In the two groups, the three acupoints around ear and distal acupoints were both selected. The acupoints of the affected side such as Yifeng (TE 17), Tinghui (GB 2), Ermen (TE 21), Zhigou (TE 6), Zhongzhu (TE 3) and Hegu (LI 4) were adopted. Yifeng (TE 17), Tinghui (GB 2) and Ermen (TE 21) were acupunctured 30-38 mm in the deep needling group and 15-20 mm in the shallow needling group. The other acupoints were conventionally acupunctured in the two groups. The needles were retained for 30 min,once a day and five times a week for all patients. The treatment was continuously for 4 weeks in the two groups. Tinnitus handicap inventory (THI) scores, tinnitus grades and visual analogue scale (VAS) for tinnitus sound levels were observed before and after treatment, and the effects of the two groups were compared. The total effective rate in the deep needling group was 59.1% (13/22), and it was better than 20.0% (4/20) in the shallow needling group (P deep needling, group, the THI score, tinnitus grade and the VAS score were improved than those before treatment (all P shallow needling group, the three above indices before and after treatment were not different in statistical significance (all P > 0.05). After treatment, all the three indices in the deep needling group were superior to those in the shallow needling group (all P shallow needling at the three acupoints.
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Fevre, Marie-Cécile; Vincent, Caroline; Picard, Julien; Vighetti, Arnaud; Chapuis, Claire; Detavernier, Maxime; Allenet, Benoît; Payen, Jean-François; Bosson, Jean-Luc; Albaladejo, Pierre
2018-02-01
Ultrasound (US) guided needle positioning is safer than anatomical landmark techniques for central venous access. Hand-eye coordination and execution time depend on the professional's ability, previous training and personal skills. Needle guidance positioning systems (GPS) may theoretically reduce execution time and facilitate needle positioning in specific targets, thus improving patient comfort and safety. Three groups of healthcare professionals (41 anaesthesiologists and intensivists, 41 residents in anaesthesiology and intensive care, 39 nurse anaesthetists) were included and required to perform 3 tasks (positioning the tip of a needle in three different targets in a silicon phantom) by using successively a conventional US-guided needle positioning and a needle GPS. We measured execution times to perform the tasks, hand-eye coordination and the number of repositioning occurrences or errors in handling the needle or the probe. Without the GPS system, we observed a significant inter-individual difference for execution time (Pgaming were found to be independent factors associated with a shorter execution time. Use of GPS attenuated the inter-individual and group variability. We observed a reduced execution time and improved hand-eye coordination in all groups as compared to US without GPS. Neither US training, video gaming nor demographic personal or professional factors were found to be significantly associated with reduced execution time when GPS was used. US associated with GPS systems may improve safety and decrease execution time by reducing inter-individual variability between professionals for needle-handling procedures. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Schulze-Hagen, Maximilian Franz, E-mail: mschulze@ukaachen.de; Pfeffer, Jochen; Zimmermann, Markus; Liebl, Martin [University Hospital RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany); Stillfried, Saskia Freifrau von [University Hospital RWTH Aachen, Department of Pathology (Germany); Kuhl, Christiane; Bruners, Philipp; Isfort, Peter [University Hospital RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany)
2017-06-15
PurposeTo evaluate the feasibility of a novel curved CT-guided biopsy needle prototype with shape memory to access otherwise not accessible biopsy targets.Methods and MaterialsA biopsy needle curved by 90° with specific radius was designed. It was manufactured using nitinol to acquire shape memory, encased in a straight guiding trocar to be driven out for access of otherwise inaccessible targets. Fifty CT-guided punctures were conducted in a biopsy phantom and 10 CT-guided punctures in a swine corpse. Biposies from porcine liver and muscle tissue were separately gained using the biopsy device, and histological examination was performed subsequently.ResultsMean time for placement of the trocar and deployment of the inner biopsy needle was ~205 ± 69 and ~93 ± 58 s, respectively, with a mean of ~4.5 ± 1.3 steps to reach adequate biopsy position. Mean distance from the tip of the needle to the target was ~0.7 ± 0.8 mm. CT-guided punctures in the swine corpse took relatively longer and required more biopsy steps (~574 ± 107 and ~380 ± 148 s, 8 ± 2.6 steps). Histology demonstrated appropriate tissue samples in nine out of ten cases (90%).ConclusionsTargets that were otherwise inaccessible via standard straight needle trajectories could be successfully reached with the curved biopsy needle prototype. Shape memory and preformed size with specific radius of the curved needle simplify the target accessibility with a low risk of injuring adjacent structures.
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Needle bar for warp knitting machines
Hagel, Adolf; Thumling, Manfred
1979-01-01
Needle bar for warp knitting machines with a number of needles individually set into slits of the bar and having shafts cranked to such an extent that the head section of each needle is in alignment with the shaft section accommodated by the slit. Slackening of the needles will thus not influence the needle spacing.
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International Nuclear Information System (INIS)
Manera, A.; Ozar, B.; Paranjape, S.; Ishii, M.; Prasser, H.-M.
2009-01-01
Measurements of two-phase flow parameters such as void-fraction, bubble velocities, and interfacial area density have been performed in an upwards air-water flow at atmospheric pressure by means of a four-tip needle-probe and a wire-mesh sensor. For the first time, a direct comparison between the two measuring techniques has been carried out. Both techniques are based on the measurement of the fluid conductivity. For void-fraction and velocity measurements, similarity exists between the two methodologies for signal analysis. A significantly different approach is followed, instead, for the estimation of the interfacial area concentration: while the evaluation based on the needle-probe signal is carried out by using projections of the gas-liquid interface velocity, the evaluation based on the wire-mesh signals consist in a full reconstruction of the bubbles interfaces. The comparison between the two techniques shows a good agreement.
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Energy Technology Data Exchange (ETDEWEB)
Manera, A. [Paul Scherrer Institute, 5232 Villigen (Switzerland); Research Center Dresden Rossendorf, Dresden (Germany)], E-mail: annalisa.manera@psi.ch; Ozar, B.; Paranjape, S.; Ishii, M. [Purdue University, West Lafayette (United States); Prasser, H.-M. [Research Center Dresden Rossendorf, Dresden (Germany); ETH Zuerich, Sonneggstrasse 3, 8092 Zuerich (Switzerland)
2009-09-15
Measurements of two-phase flow parameters such as void-fraction, bubble velocities, and interfacial area density have been performed in an upwards air-water flow at atmospheric pressure by means of a four-tip needle-probe and a wire-mesh sensor. For the first time, a direct comparison between the two measuring techniques has been carried out. Both techniques are based on the measurement of the fluid conductivity. For void-fraction and velocity measurements, similarity exists between the two methodologies for signal analysis. A significantly different approach is followed, instead, for the estimation of the interfacial area concentration: while the evaluation based on the needle-probe signal is carried out by using projections of the gas-liquid interface velocity, the evaluation based on the wire-mesh signals consist in a full reconstruction of the bubbles interfaces. The comparison between the two techniques shows a good agreement.
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Kakizawa, Hideaki; Toyota, Naoyuki; Hieda, Masashi; Hirai, Nobuhiko; Tachikake, Toshihiro; Matsuura, Noriaki; Oda, Miyo; Ito, Katsuhide
2010-09-01
The purpose of this study is to evaluate the risk factors for the severity of pneumothorax after computed tomography (CT)-guided percutaneous lung biopsy using the single-needle method. We reviewed 91 biopsy procedures for 90 intrapulmonary lesions in 89 patients. Patient factors were age, sex, history of ipsilateral lung surgery and grade of emphysema. Lesion factors were size, location and pleural contact. Procedure factors were position, needle type, needle size, number of pleural punctures, pleural angle, length of needle passes in the aerated lung and number of harvesting samples. The severity of pneumothorax after biopsy was classified into 4 groups: "none", "mild", "moderate" and "severe". The risk factors for the severity of pneumothorax were determined by multivariate analyzing of the factors derived from univariate analysis. Pneumothorax occurred in 39 (43%) of the 91 procedures. Mild, moderate, and severe pneumothorax occurred in 24 (26%), 8 (9%) and 7 (8%) of all procedures, respectively. Multivariate analysis showed that location, pleural contact, number of pleural punctures and number of harvesting samples were significantly associated with the severity of pneumothorax (p < 0.05). In conclusion, lower locations and non-pleural contact lesions, increased number of pleural punctures and increased number of harvesting samples presented a higher severity of pneumothorax.
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International Nuclear Information System (INIS)
Kakizawa, Hideaki; Hieda, Masashi; Oda, Miyo; Toyota, Naoyuki; Hirai, Nobuhiko; Tachikake, Toshihiro; Matsuura, Noriaki; Ito, Katsuhide
2010-01-01
The purpose of this study is to evaluate the risk factors for the severity of pneumothorax after computed tomography (CT)-guided percutaneous lung biopsy using the single-needle method. We reviewed 91 biopsy procedures for 90 intrapulmonary lesions in 89 patients. Patient factors were age, sex, history of ipsilateral lung surgery and grade of emphysema. Lesion factors were size, location and pleural contact. Procedure factors were position, needle type, needle size, number of pleural punctures, pleural angle, length of needle passes in the aerated lung and number of harvesting samples. The severity of pneumothorax after biopsy was classified into 4 groups: 'none', 'mild', 'moderate' and 'severe'. The risk factors for the severity of pneumothorax were determined by multivariate analyzing of the factors derived from univariate analysis. Pneumothorax occurred in 39 (43%) of the 91 procedures. Mild, moderate, and severe pneumothorax occurred in 24 (26%), 8 (9%) and 7 (8%) of all procedures, respectively. Multivariate analysis showed that location, pleural contact, number of pleural punctures and number of harvesting samples were significantly associated with the severity of pneumothorax (p<0.05). In conclusion, lower locations and non-pleural contact lesions, increased number of pleural punctures and increased number of harvesting samples presented a higher severity of pneumothorax. (author)
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International Nuclear Information System (INIS)
Safriel, Yair; Ang, Roberto; Ali, Muhammed
2008-01-01
Introduction. To review the safety and efficacy of gadolinium in spine pain management procedures in patients at high risk for a contrast reaction and who are not suitable candidates for the use of standard non-ionic contrast. Methods. We reviewed records over a 61-month period of all image-guided spinal pain management procedures where patients had allergies making them unsuitable candidates for standard non-ionic contrast and where gadolinium was used to confirm needle tip placement prior to injection of medication. Results. Three hundred and four outpatients underwent 527 procedures. A spinal needle was used in all but 41 procedures. Gadolinium was visualized using portable C-arm fluoroscopy in vivo allowing for confirmation of needle tip location. The gadolinium dose ranged from 0.2 to 10 ml per level. The highest dose received by one patient was 15.83 ml intradiscally during a three-level discogram. Three hundred and one patients were discharged without complication or known delayed complications. One patient had documented intrathecal injection but without sequelae and 2 patients who underwent cervical procedures experienced seizures requiring admission to the intensive care unit. Both the latter patients were discharged without any further complications. Conclusion. Based on our experience we recommend using gadolinium judiciously for needle tip confirmation. We feel more confident using gadolinium in the lumbar spine and in cervical nerve blocks. Gadolinium should probably not be used as an injectate volume expander. The indications for gadolinium use in cervical needle-guided spine procedures are less clear and use of a blunt-tipped needle should be considered
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SU-F-J-10: Sliding Mode Control of a SMA Actuated Active Flexible Needle for Medical Procedures
International Nuclear Information System (INIS)
Podder, T
2016-01-01
Purpose: In medical interventional procedures such as brachytherapy, ablative therapies and biopsy precise steering and accurate placement of needles are very important for anatomical obstacle avoidance and accurate targeting. This study presents the efficacy of a sliding mode controller for Shape Memory Alloy (SMA) actuated flexible needle for medical procedures. Methods: Second order system dynamics of the SMA actuated active flexible needle was used for deriving the sliding mode control equations. Both proportional-integral-derivative (PID) and adaptive PID sliding mode control (APIDSMC) algorithms were developed and implemented. The flexible needle was attached at the end of a 6 DOF robotic system. Through LabView programming environment, the control commands were generated using the PID and APIDSMC algorithms. Experiments with artificial tissue mimicking phantom were performed to evaluate the performance of the controller. The actual needle tip position was obtained using an electromagnetic (EM) tracking sensor (Aurora, NDI, waterloo, Canada) at a sampling period of 1ms. During experiment, external disturbances were created applying force and thermal shock to investigate the robustness of the controllers. Results: The root mean square error (RMSE) values for APIDSMC and PID controllers were 0.75 mm and 0.92 mm, respectively, for sinusoidal reference input. In the presence of external disturbances, the APIDSMC controller showed much smoother and less overshooting response compared to that of the PID controller. Conclusion: Performance of the APIDSMC was superior to the PID controller. The APIDSMC was proved to be more effective controller in compensating the SMA uncertainties and external disturbances with clinically acceptable thresholds.
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SU-F-J-10: Sliding Mode Control of a SMA Actuated Active Flexible Needle for Medical Procedures
Energy Technology Data Exchange (ETDEWEB)
Podder, T [University Hospitals Case Medical Center, Cleveland, OH (United States)
2016-06-15
Purpose: In medical interventional procedures such as brachytherapy, ablative therapies and biopsy precise steering and accurate placement of needles are very important for anatomical obstacle avoidance and accurate targeting. This study presents the efficacy of a sliding mode controller for Shape Memory Alloy (SMA) actuated flexible needle for medical procedures. Methods: Second order system dynamics of the SMA actuated active flexible needle was used for deriving the sliding mode control equations. Both proportional-integral-derivative (PID) and adaptive PID sliding mode control (APIDSMC) algorithms were developed and implemented. The flexible needle was attached at the end of a 6 DOF robotic system. Through LabView programming environment, the control commands were generated using the PID and APIDSMC algorithms. Experiments with artificial tissue mimicking phantom were performed to evaluate the performance of the controller. The actual needle tip position was obtained using an electromagnetic (EM) tracking sensor (Aurora, NDI, waterloo, Canada) at a sampling period of 1ms. During experiment, external disturbances were created applying force and thermal shock to investigate the robustness of the controllers. Results: The root mean square error (RMSE) values for APIDSMC and PID controllers were 0.75 mm and 0.92 mm, respectively, for sinusoidal reference input. In the presence of external disturbances, the APIDSMC controller showed much smoother and less overshooting response compared to that of the PID controller. Conclusion: Performance of the APIDSMC was superior to the PID controller. The APIDSMC was proved to be more effective controller in compensating the SMA uncertainties and external disturbances with clinically acceptable thresholds.
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Tip studies using CFD and comparison with tip loss models
DEFF Research Database (Denmark)
Hansen, Martin Otto Laver; Johansen, J.
2004-01-01
The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD......The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD...
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International Nuclear Information System (INIS)
Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron
2010-01-01
Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 μm tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 μm, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154±113 μm. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.
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Energy Technology Data Exchange (ETDEWEB)
Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron [Biomedical Engineering Graduate Program and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, Department of Surgery, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Electrical and Computer Engineering, Department of Medical Biophysics, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada)
2010-04-15
Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 {mu}m tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 {mu}m, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154{+-}113 {mu}m. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.
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Chae, In Hye; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Park, Vivian Y; Kwak, Jin Young
2017-07-01
To compare post-biopsy hematoma rates between ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy, and to investigate risk factors for post-biopsy hematoma. A total of 5304 thyroid nodules which underwent ultrasound guided biopsy were included in this retrospective study. We compared clinical and US features between patients with and without post-biopsy hematoma. Associations between these features and post-biopsy hematoma were analyzed. Post-biopsy hematoma rate was 0.8% (43/5121) for ultrasound guided-fine needle aspiration and 4.9% (9/183) for ultrasound guided-core needle biopsy (P core needle biopsy (9/179, 5.0%) than with ultrasound guided-fine needle aspiration (9/1138, 0.8%) (P core needle biopsy was the only significant risk factor for post-biopsy hematoma (adjusted Odds Ratio, 6.458, P core needle biopsy than in ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy was the only independent factor of post-biopsy hematoma in thyroid nodules.
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Analytic theory for the selection of 2-D needle crystal at arbitrary Peclet number
Tanveer, Saleh
1989-01-01
An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.
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Guérin, Marceau; Martin-Benito, Dario; von Arx, Georg; Andreu-Hayles, Laia; Griffin, Kevin L; Hamdan, Rayann; McDowell, Nate G; Muscarella, Robert; Pockman, William; Gentine, Pierre
2018-02-01
In the southwestern USA, recent large-scale die-offs of conifers raise the question of their resilience and mortality under droughts. To date, little is known about the interannual structural response to droughts. We hypothesized that piñon pines ( Pinus edulis ) respond to drought by reducing the drop of leaf water potential in branches from year to year through needle morphological adjustments. We tested our hypothesis using a 7-year experiment in central New Mexico with three watering treatments (irrigated, normal, and rain exclusion). We analyzed how variation in "evaporative structure" (needle length, stomatal diameter, stomatal density, stomatal conductance) responded to watering treatment and interannual climate variability. We further analyzed annual functional adjustments by comparing yearly addition of needle area (LA) with yearly addition of sapwood area (SA) and distance to tip ( d ), defining the yearly ratios SA:LA and SA:LA/ d . Needle length ( l ) increased with increasing winter and monsoon water supply, and showed more interannual variability when the soil was drier. Stomatal density increased with dryness, while stomatal diameter was reduced. As a result, anatomical maximal stomatal conductance was relatively invariant across treatments. SA:LA and SA:LA/ d showed significant differences across treatments and contrary to our expectation were lower with reduced water input. Within average precipitation ranges, the response of these ratios to soil moisture was similar across treatments. However, when extreme soil drought was combined with high VPD, needle length, SA:LA and SA:LA/ d became highly nonlinear, emphasizing the existence of a response threshold of combined high VPD and dry soil conditions. In new branch tissues, the response of annual functional ratios to water stress was immediate (same year) and does not attempt to reduce the drop of water potential. We suggest that unfavorable evaporative structural response to drought is compensated
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Atom sharp needles, the missing link in microneedle drug delivery
Wissink, J.; Berenschot, Johan W.; Tas, Niels Roelof
2008-01-01
The skin barrier function is a major challenge for delivery of drugs via the skin. Located in the outermost layer of the skin, the stratum corneum (SC) consists of dead cells embedded in lipid regions, only 10-20 microm thick, tough but flexible and elastic. Hyperdermic needles penetrate the skin
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21 CFR 880.5580 - Acupuncture needle.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle. The...
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Wu, Jiani; Liu, Baoyan; Li, Ning; Sun, Jianhua; Wang, Lingling; Wang, Liping; Cai, Yuying; Ye, Yongming; Liu, Jun; Wang, Yang; Liu, Zhishun
2014-12-01
Aupuncture is widely used for functional constipation. Effect of acupuncture might be related to the depth of needling; however, the evidence is limited. This trial aimed to evaluate the effect and safety of deep needling and shallow needling for functional constipation, and to assess if the deep needling and shallow needling are superior to lactulose. We conducted a prospective, superiority-design, 5-center, 3-arm randomized controlled trial. A total of 475 patients with functional constipation were randomized to the deep needling group (237), shallow needling group (119), and lactulose-controlled group (119) in a ratio of 2:1:1. Sessions lasted 30 minutes each time and took place 5 times a week for 4 weeks in 2 acupuncture groups. Participants in the lactulose group took lactulose orally for 16 continuous weeks. The primary outcome was the change from baseline of mean weekly spontaneous bowel movements (SBMs) during week 1 to 4 (changes from the baselines of the weekly SBMs at week 8 and week 16 in follow-up period were also assessed simultaneously). Secondary outcomes were the weekly SBMs of each assessing week, the mean score change from the baseline of constipation-related symptoms over week 1 to 4, and the time to the first SBM. Emergency drug usage and adverse effects were monitored throughout the study.SBMs and constipation-related symptoms were all improved in the 3 groups compared with baseline at each time frame (Pdeep needling group, 2 (1.75) in the shallow needling group, and 2 (2) in the lactulose group (P>0.05, both compared with the lactulose group). The changes of mean weekly SBMs at week 8 and week 16 in the follow-up period were 2 (2), 2 (2.5) in the deep needling group, 2 (3), 1.5 (2.5) in the shallow needling group, and 1 (2), 1 (2) in the lactulose group (Pdeep or shallow needling group. Deep and shallow needling at Tianshu (ST25) can improve intestinal function remarkably and safely. Therapeutic effects of deep and shallow needling are not
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Reduction of Zygomatic Arch Isolated Fracture Using Ultra Sound and Needle Marking.
Kim, Jun Sik; Park, Young Ji; Lee, Yoon Jung; Kim, Nam Gyun; Lee, Kyung Suk
2016-12-01
Zygomatic arch is a bony arch constituting the lateral midface, which consists of 25% of all midface fractures. There are a number of ways to evaluate the extent of zygomatic arch fracture. Some authors have reported successful treatment outcomes using ultrasound (U/S). To add to the previous methods, we have considered ways to accurately display the location of the fracture line while using U/S with 23 gauge needle marking. We introduce our method, which provided satisfactory results for reduction using a portable U/S, and it can evaluate the fracture line simultaneously when reduction of an isolated zygomatic arch fracture is necessary, and needle marking, which can easily point out the fracture line on U/S. We studied 21 patients with an isolated zygomatic arch fracture who underwent closed reduction using U/S and needle marking between 2013 and 2015. We achieved satisfactory results in all our cases with respect to reduction by using the Dingman elevator after performing a temporal approach incision, while confirming relative positioning between needle marking and zygomatic fracture at the same time, after insertion of a 23 gauge needle in the skin above the zygomatic arch fracture line parallel to it. We treated 21 patients with an isolated zygomatic arch fracture using U/S and the needle marking method, which provided satisfactory results because the extent of reduction of the fracture could be evaluated in real-time during the operation and exposure to radiation was reduced.
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Usefulness of CT-guided trans-bronchial needle aspiration biopsy for mediastinal lymph nodes
International Nuclear Information System (INIS)
Cui Bing; Rong Fu
2001-01-01
Objective: To determine the nature of enlarged mediastinal lymph nodes, the study of CT-guided trans-bronchial needle aspiration biopsy (CT-TBNA) was conducted. Methods: According to classification and locating standard of mediastinal lymph nodes, CT-TBNA was performed in 158 mediastinal lymph nodes of 73 patients, including 54 primary lung cancer with enlarged mediastinal lymph nodes, 5 malignant lymphoma, 3 mediastinal abscess and 11 mediastinal inflammatory adenopathy. Results: CT confirmed that the needles were inside all 158 lymph nodes. Adequate aspirates for histologic and/or cytologic diagnosis were obtained in 136 of 158(86%) lymph node biopsies. No serious complications occurred. Conclusion: Locating standard of CT-guided TBNA was reliable. Puncture was safe and cost-effective. CT-TBNA was important for ascertaining the nature of mediastinal adenopathy and staging of neoplasms
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[Stiletto needle and needle-knife for influence of gravity index in treating knee osteoarthritis].
Gu, Li-Jun; Zhang, Bin; Li, Wen-Hua; Tang, Yan; Dong, Fu-Hui
2017-12-25
To explore stiletto needle and needle-knife for influence of double sufficient weight in treating knee osteoarthritis patients. One hundred and thirteen early and medium term knee osteoarthritis patients were randomly divided into three groups, including stiletto needle group(38 cases), needle-knife group (38 cases) and voltaren group (37 cases). In stiletto needle group, there were 13 males and 25 females with an average of(55.87±7.72) years old, treated by stiletto needle once a week, and 2 weeks were a course; there were 11 males and 27 females in needle-knife group with an average of(57.11±7.07) years old, treated by acupotome once a week, and 2 weeks were a course; there were 12 males and 25 females in voltaren group with an average age of(57.62±8.08) years old, treated by votalin emulsion smearing 3 to 5 cm on painful area of knee joint, three times a day for 2 weeks; 36 patients in normal group, including 11 males and 25 females with a mean age of (55.28±7.55) years old, treated with nothing. Gravitational four lattice used to measure bipedal back and forth load before and after treatment in further observe weight-bearing situation among three groups, d value, which was the distance from center of gravity to original point, was measured as a obvervational index, JOA score was used to evaluate clinical effect. Five patients were fall out, including 2 patients in stiletto needle group, 2 patients in needle-knife group and 1 patient in voltaren group. Other 108 patients were followed-up from 28 to 35 d with an average of 30 d, and without untoward effect. There was significant difference in d value between treatment group and control group at 1 month after treatment( P 0.05), and d value was decreased before treatment than that of after treatment. There was no significant difference in JOA score among treatment group after treatment at 1 month( P 0.05) after treatment at 1 month. Stiletto needle, needle-knife and voltaren for the treatment of knee
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Ning, Shaoli; Zhao, Lihua; Xu, Lingjun; Huang, Yu; Pang, Yong; Huang, Dingjian
2016-01-01
To compare the effects between slow twisting needle insertion and tubing needle insertion. With cross-over design, 100 healthy young subjects (half male and half female) aged from 19 to 23 years were randomly divided into two groups by random digital table, 50 cases in each one. At the first stage, subjects in the group A were treated with slow twisting needle insertion while, subjects in,the group B were treated with tubing needle insertion. One week later, the procedure of second stage was performed alternately. The needle was inserted into Neiguan (PC 6) with two methods by one acupuncturist. The needle was retained for 5 min before removal. Five min before needle insertion as well as needle withdrawal and 30 min after needle withdrawal, ZXG-E automatic cardiovascular diagnostic apparatus was used to test cardiovascular function. At the tim of needle withdrawal, slow twisting needle insertion could improve effect work of kinetics (EWK), effective blood volume (BV) and reduce elastic expansion coefficient of blood vessel (FEK) and left ventricular spray blood impedance (VER), which was significantly different from tubing needle insertion (all P 0.05). The slow twisting needle insertion is significantly superior to tubing needle insertion on lowering vascular tension and VER, improving EWK and BV.
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Gonzalez, David A.; Hardy, Luke A.; Hutchens, Thomas C.; Irby, Pierce B.; Fried, Nathaniel M.
2018-02-01
This study characterizes laser-induced vapor bubbles for five distal fiber optic tip configurations, to provide insight into stone retropulsion experienced during laser ablation of kidney stones. A TFL with 1908-nm wavelength delivered 34 mJ energy per pulse at 500-μs pulse duration through five different fibers: 100-μm-core/170-μm-OD bare fiber tip, 150-μm- to 300-μm-core tapered fiber tip, 100-μm-core/300-μm-OD ball tip fiber, 100-μm-core/340- μm-OD hollow steel tip fiber, and 100-μm-core/560-μm-OD muzzle brake fiber tip. A high speed camera with 10- μm spatial and 9.5-μs temporal resolution imaged vapor bubble dynamics. A needle hydrophone measured pressure transients in forward (0°) and side (90°) directions while placed at a 6.8 +/- 0.4 mm distance from fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7/1.5 mm, for bare, tapered, ball, hollow steel, and muzzle tips, respectively (n=5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n=5). For hollow steel tip, forward pressure was 4× higher than for bare fiber. For the muzzle brake fiber tip, forward pressure was 5× lower than for bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle tip reduced forward pressure by partially venting vapors through side holes, consistent with lower stone retropulsion observed in previous reports.
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Analytic theory for the selection of a two-dimensional needle crystal at arbitrary Peclet number
Tanveer, S.
1989-01-01
An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.
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A Rotor Tip Vortex Tracing Algorithm for Image Post-Processing
Overmeyer, Austin D.
2015-01-01
A neurite tracing algorithm, originally developed for medical image processing, was used to trace the location of the rotor tip vortex in density gradient flow visualization images. The tracing algorithm was applied to several representative test images to form case studies. The accuracy of the tracing algorithm was compared to two current methods including a manual point and click method and a cross-correlation template method. It is shown that the neurite tracing algorithm can reduce the post-processing time to trace the vortex by a factor of 10 to 15 without compromising the accuracy of the tip vortex location compared to other methods presented in literature.
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[Design and application of silver needle-knife].
Sun, Guodong; Shi, Bin; Zhang, Benwu; Xu, Haidong
2015-04-01
A silver needle-knife which has the dual function of silver needle and needle-knife is designed. The main components of this silver needle-knife are approximately 50% silver and approximately 50% nichrome. The silver needle-knife is composed of five parts, including needle-knife tail, spiral handle; steering handle, needle-knife body and needle-knife edge. It converges the advantages of needle-knife and silver needle, which can cut loose of diseased tissue and peel adhesion of lesions, but also be heated with moxa cone and thermal therapeutic instrument, and connect with electroacupuncture apparatus. It has the function of warming channel and removing coldness, dispelling wind and eliminating dampness, resolving spasm and relieving pain, dredging the channel and so on. Due to the spiral handle and the steering handle, the operation is easier, which reduces the blindness of cutting and increase the safety. It is mainly used for soft tissue injury, rheumatism and rheumatoid arthritis, as well as degenerative diseases of spine and joint, and it has obvious efficacy on some internal medical diseases.
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International Nuclear Information System (INIS)
Wu, Reng-Hong; Tzeng, Wen-Sheng; Lee, Wei-Jing; Chang, Shih-Chin; Chen, Chia-Huei; Fung, Jui-Lung; Wang, Yen-Jen; Mak, Chee-Wai
2012-01-01
Purpose: To evaluate the complication rates and diagnostic accuracy of two different CT-guided transthoracic cutting needle biopsy techniques: coaxial method and single needle method. Methods: This study involved 198 consecutive subjects with 198 intrathoracic lesions. The first 98 consecutive subjects received a single needle cutting technique and the next 100 consecutive subjects received a coaxial technique. Both groups were compared in relation the diagnostic accuracy and complication rates. Results: No significant difference was found between the two groups concerning patient characteristics, lesions and procedure variables. There was a borderline statistical difference in the incidence of pneumothorax at within 24-h post biopsy between patients in the single needle group (5%) and the coaxial group (13%) (P = 0.053). Little difference was found in the pneumothorax rate at immediately post biopsy between the two groups, which was 28% in the single needle group and 31% in the coaxial group. There was no significant difference in the hemoptysis rate between the two groups, which was 9.2% in the single needle group and 11% in the coaxial group. Both techniques yielded an overall diagnostic accuracy of 98% for malignant lesions with similar sensitivity (single needle: 96.9% vs. coaxial: 96.4%) and specificity (single needle: 100% vs. coaxial: 100%). Conclusion: There is little difference in the pneumothorax rates and bleeding complications between patients who either received a single needle or a coaxial transthoracic cutting biopsy. Both techniques produce an overall diagnostic accuracy of 98% for malignant lesions.
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International Nuclear Information System (INIS)
Sarfraz, T.; Bashir, S.; Tariq, H.; Malik, T.M.
2013-01-01
Background: Fine Needle Aspiration Cytology (FNAC) of external swellings may yield different specimen adequacy depending on different gauge needles used for aspiration. Objective: To compare the specimen adequacy aspirated by various gauge (21 and 22) needles in external palpable swellings of lymph nodes, thyroid gland, salivary glands, breast and soft tissue. Study Design: Comparative cross sectional study. Duration: Six months (1st Jan 2012 to 30th June 2012). Setting: Histopathology/Cytology department Combined Military Hospital Peshawar (Pakistan). Methodology: This was a prospective study of 200 cases in which FNAC was performed with either 21 or 22 gauge needles (100 cases with 21 gauge and 100 with 22 gauge needles). Equal number of aspirations were done with 21 and 22 gauge needles from the swellings of thyroid gland, lymph nodes, salivary glands, breast and soft tissue. Results were analyzed for specimen adequacy by using SPSS 17. Results: A total number of 200 cases were recruited in this study, out of which 100 were aspirated with 21 gauge needles and 100 with 22 gauge needles. Specimen adequacy in swellings of thyroid, lymph nodes and salivary glands was better with 22 gauge amounting 90%, 80% and 80% respectively, as compared to yield with 21 gauge needles which was 85%, 70% and 60% respectively. On the other hand in swellings of breast and soft tissue, the specimen adequacy was better with 21 gauge needles giving 98% and 90 % adequate yield respectively as compared to 22 gauge needles which was 70% and 40 % respectively. Conclusion: Needles of smaller gauge (22 gauge) give a better yield in swellings of thyroid, lymph nodes and salivary gland while in swellings of breast and soft tissue sample adequacy is better with larger gauge needle (21 gauge). (author)
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Computational Investigation of Novel Tip Leakage Mitigation Methods for High Pressure Turbine Blades
Ibrahim, Mounir; Gupta, Abhinav; Shyam, Vikram
2014-01-01
This paper presents preliminary findings on a possible approach to reducing tip leakage losses. In this paper a computational study was conducted on the Energy Efficient Engine (EEE) High Pressure Turbine (HPT) rotor tip geometry using the commercial numerical solver ANSYS FLUENT. The flow solver was validated against aerodynamic data acquired in the NASA Transonic Turbine Blade Cascade facility. The scope of the ongoing study is to computationally investigate how the tip leakage and overall blade losses are affected by (1) injection from the tip near the pressure side, (2) injection from the tip surface at the camber line, and (3) injection from the tip surface into the tip separation bubble. The objective is to identify the locations on the tip surface at which to place appropriately configured blowing keeping in mind the film cooling application of tip blowing holes. The validation was conducted at Reynolds numbers of 85,000, 343,000, and 685,000 and at engine realistic flow conditions. The coolant injection simulations were conducted at a Reynolds number of 343,000 based on blade chord and inlet velocity and utilized the SST turbulence model in FLUENT. The key parameters examined are the number of jets, jet angle and jet location. A coolant to inlet pressure ratio of 1.0 was studied for angles of +30 deg, -30 deg, and 90 deg to the local free stream on the tip. For the 3 hole configuration, 3 holes spaced 3 hole diameters apart with length to diameter ratio of 1.5 were used. A simulation including 11 holes along the entire mean camber line is also presented (30 deg toward suction side). In addition, the effect of a single hole is also compared to a flat tip with no injection. The results provide insight into tip flow control methods and can be used to guide further investigation into tip flow control. As noted in past research it is concluded that reducing leakage flow is not necessarily synonymous with reducing losses due to leakage.
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Ibrahim, Irwani; Yau, Ying Wei; Ong, Lizhen; Chan, Yiong Huak; Kuan, Win Sen
2015-03-01
Arterial punctures are important procedures performed by emergency physicians in the assessment of ill patients. However, arterial punctures are painful and can create anxiety and needle phobia in patients. The pain score of radial arterial punctures were compared between the insulin needle and the standard 23-gauge hypodermic needle. In a randomized controlled crossover design, healthy volunteers were recruited to undergo bilateral radial arterial punctures. They were assigned to receive either the insulin or the standard needle as the first puncture, using blocked randomization. The primary outcome was the pain score measured on a 100-mm visual analogue scale (VAS) for pain, and secondary outcomes were rate of hemolysis, mean potassium values, and procedural complications immediately and 24 hours postprocedure. Fifty healthy volunteers were included in the study. The mean (±standard deviation) VAS score in punctures with the insulin needle was lower than the standard needle (23 ± 22 mm vs. 39 ± 24 mm; mean difference = -15 mm; 95% confidence interval = -22 mm to -7 mm; p standard needle (31.3% vs. 11.6%, p = 0.035; and 4.6 ±0.7 mmol/L vs. 4.2 ±0.5 mmol/L, p = 0.002). Procedural complications were lower in punctures with the insulin needle both immediately postprocedure (0% vs. 24%; p standard needles. However, due to the higher rate of hemolysis, its use should be limited to conditions that do not require a concurrent potassium value in the same blood sample. © 2015 by the Society for Academic Emergency Medicine.
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Okumura, Yuri; Hidaka, Hiroshi; Seiji, Kazumasa; Nomura, Kazuhiro; Takata, Yusuke; Suzuki, Takahiro; Katori, Yukio
2015-02-01
The first objective was to describe a novel case of migration of a broken dental needle into the parapharyngeal space. The second was to address the importance of simulation elucidating visualization of such a thin needle under X-ray fluoroscopy. Clinical case records (including computed tomography [CT] and surgical approaches) were reviewed, and a simulation experiment using a head phantom was conducted using the same settings applied intraoperatively. A 36-year-old man was referred after failure to locate a broken 31-G dental needle. Computed tomography revealed migration of the needle into the parapharyngeal space. Intraoperative X-ray fluoroscopy failed to identify the needle, so a steel wire was applied as a reference during X-ray to locate the foreign body. The needle was successfully removed using an intraoral approach with tonsillectomy under surgical microscopy. The simulation showed that the dental needle was able to be identified only after applying an appropriate compensating filter, contrasting with the steel wire. Meticulous preoperative simulation regarding visual identification of dental needle foreign bodies is mandatory. Intraoperative radiography and an intraoral approach with tonsillectomy under surgical microscopy offer benefits for accessing the parapharyngeal space, specifically for cases medial to the great vessels. © The Author(s) 2014.
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The role of MR angiography before transjugular placement of a portosystemic stent shunt (TIPS)
International Nuclear Information System (INIS)
Mueller, M.F.; Siewert, B.; Kim, D.; Edelman, R.R.; Stokes, K.R.; Finn, J.P.
1994-01-01
The authors employed magnetic resonance angiography (MRA) to guide catheter placement for transjugular intrahepatic portosystemic stent shunt (TIPS) procedures in 14 of 24 patients, and compared the results to the 10 patients who did not have prior panning based on MRA. Two-dimensional time-of-flight venography was performed during breath holding, and projection venograms were formatted in sagittal, coronal and axial planes. MRA defined venous anatomy sufficiently well to shorten the procedure and helped to minimize invasiveness. With MRA guidance, intrahepatic needle punctures were significantly fewer (without MRA guidance: mean 12.1; with MRA guidance: mean 3.5, p [de
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Gonzalez, David A.; Hardy, Luke A.; Hutchens, Thomas C.; Irby, Pierce B.; Fried, Nathaniel M.
2018-03-01
This study characterizes laser-induced vapor bubble dynamics for five different distal fiber optic tip configurations, to provide insight into stone retropulsion commonly experienced during laser ablation of kidney stones. A thulium fiber laser with 1908-nm wavelength delivered 34-mJ energy per pulse at 500-μs pulse duration through five different fibers such as 100-μm-core / 170-μm-OD bare fiber tip, 150- to 300-μm-core tapered fiber tip, 100-μm-core / 300-μm-OD ball tip fiber, 100-μm-core / 340-μm-OD hollow steel tip fiber, and 100-μm-core / 560-μm-OD muzzle brake fiber tip. A high-speed camera with 10-μm-spatial and 9.5-μs-temporal resolution was used to image the vapor bubble dynamics. A needle hydrophone measured pressure transients in the forward (0 deg) and side (90 deg) directions while placed at a 6.8 ± 0.4 mm distance from the distal fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7 / 1.5 mm, for bare, tapered, ball, hollow steel, and muzzle brake fiber tips, respectively (n = 5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n = 5). For the hollow steel tip, forward pressure was 4 × higher than for the bare fiber. For the muzzle brake fiber tip, forward pressure was 5 × lower than the bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle brake fiber tip reduced forward pressure by partially venting vapors through the portholes, which is consistent with the observation of lower stone retropulsion in previous reports.
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Directory of Open Access Journals (Sweden)
Camille Chesnel
Full Text Available Twenty-two percent of institutionalised elderly persons have muscle contractures. Contractures have important functional consequences, rendering hygiene and positioning in bed or in a chair difficult. Medical treatment (such as botulinum toxin injections, physiotherapy or positioning is not very effective and surgery may be required. Surgery is carried out in the operating theatre, under local or general anaesthesia but is often not possible in fragile patients. Mini-invasive tenotomy could be a useful alternative as it can be carried out in ambulatory care, under local anaesthesia.To evaluate the effectiveness of percutaneous needle tenotomy and the risks of damage to adjacent structures in cadavers.Thirty two doctors who had never practiced the technique (physical medicine and rehabilitation specialists, geriatricians and orthopaedic surgeons carried out 401 tenotomies on the upper and lower limbs of 8 fresh cadavers. A 16G needle was used percutaneous following location of the tendons. After each tenotomy, a neuro-orthopaedic surgeon and an anatomist dissected the area in order to evaluate the success of the tenotomy and any adjacent lesions which had occurred.Of the 401 tenotomies, 72% were complete, 24.9% partial and 2.7% failed. Eight adjacent lesions occurred (2%: 4 (1% in tendons or muscles, 3 (0.7% in nerves and 1 (0.2% in a vessel.This percutaneous needle technique effectively ruptured the desired tendons, with few injuries to adjacent structures. Although this study was carried out on cadavers, the results suggest it is safe to carry out on patients.
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Chesnel, Camille; Genêt, François; Almangour, Waleed; Denormandie, Philippe; Parratte, Bernard; Schnitzler, Alexis
2015-01-01
Twenty-two percent of institutionalised elderly persons have muscle contractures. Contractures have important functional consequences, rendering hygiene and positioning in bed or in a chair difficult. Medical treatment (such as botulinum toxin injections, physiotherapy or positioning) is not very effective and surgery may be required. Surgery is carried out in the operating theatre, under local or general anaesthesia but is often not possible in fragile patients. Mini-invasive tenotomy could be a useful alternative as it can be carried out in ambulatory care, under local anaesthesia. To evaluate the effectiveness of percutaneous needle tenotomy and the risks of damage to adjacent structures in cadavers. Thirty two doctors who had never practiced the technique (physical medicine and rehabilitation specialists, geriatricians and orthopaedic surgeons) carried out 401 tenotomies on the upper and lower limbs of 8 fresh cadavers. A 16G needle was used percutaneous following location of the tendons. After each tenotomy, a neuro-orthopaedic surgeon and an anatomist dissected the area in order to evaluate the success of the tenotomy and any adjacent lesions which had occurred. Of the 401 tenotomies, 72% were complete, 24.9% partial and 2.7% failed. Eight adjacent lesions occurred (2%): 4 (1%) in tendons or muscles, 3 (0.7%) in nerves and 1 (0.2%) in a vessel. This percutaneous needle technique effectively ruptured the desired tendons, with few injuries to adjacent structures. Although this study was carried out on cadavers, the results suggest it is safe to carry out on patients.
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DEFF Research Database (Denmark)
Ann Praestmark Juul, Kezia; Bengtsson, Henrik; Eyving, Bente
2012-01-01
, little is known about local drug delivery in relation to needle length and thickness. This study aimed to compare deposition depth and backflow from three hypodermic needles of 3 mm 34G (0.19 mm), 5 mm 32G (0.23 mm), and 8 mm 30G (0.30 mm) in length and thickness. METHODS: Ex vivo experiments were......BACKGROUND: Thinner and shorter needles for subcutaneous administration are continuously developed. Previous studies have shown that a thinner needle causes fewer occurrences of painful needle insertions and that a shorter needle decreases the occurrence of painful intramuscular injections. However...... depth, the bulk of the injection was in the subcutaneous tissue and did not propagate from subcutis into dermis. With the 8 mm 30G needle all injections apart from one intramuscular injection were located in the subcutaneous layer. The volume depositions peaked in 4-5 mm depth for the 3 mm 34G needle...
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Physical Properties Of Acupuncture Needles: Do Disposable Acupuncture Needles Break With Normal Use
2016-06-01
Orofacial Pain Graduate...JOURNAL PHYSICAL PROPERTIES OF ACUPUNCTURE NEEDLES: DO DISPOSABLE ACUPUNCTURE NEEDLES BREAK WITH NORMAL USE? James Kyle Vick DDS, Orofacial Pain ...MS CAPT, DC, USN Orofacial Pain Department Head Naval Postgraduate Dental School vi TABLE OF CONTENTS GUIDELINE I. TITLE
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Transcaval TIPS in patients with failed revision of occluded previous TIPS
Energy Technology Data Exchange (ETDEWEB)
Seong, Chang Kyu; Kim, Yong Joo; Shin, Tae Beom; Park, Hyo Yong; Kim, Tae Hun; Kang, Duk Sik [Kyungpook National University School of Medicine, Daegu (Korea, Republic of)
2001-12-01
To determine the feasibility of transcaval transjugular intrahepatic portosystemic shunt (TIPS) in patients with occluded previous TIPS. Between February 1996 and December 2000 we performed five transcaval TIPS procedures in four patients with recurrent gastric cardiac variceal bleeding. All four had occluded TIPS, which was between the hepatic and portal vein. The interval between initial TIPS placement and revisional procedures with transcaval TIPS varied between three and 31 months; one patient underwent transcaval TIPS twice, with a 31-month interval. After revision of the occluded shunt failed, direct cavoportal puncture at the retrohepatic segment of the IVC was attempted. Transcaval TIPS placement was technically successful in all cases. In three, tractography revealed slight leakage of contrast materials into hepatic subcapsular or subdiaphragmatic pericaval space. There was no evidence of propagation of extravasated contrast materials through the retroperitoneal space or spillage into the peritoneal space. After the tract was dilated by a bare stent, no patient experienced trans-stent bleeding and no serious procedure-related complications occurred. After successful shunt creation, variceal bleeding ceased in all patients. Transcaval TIPS placement is an effective and safe alternative treatment in patients with occluded previous TIPS and no hepatic veins suitable for new TIPS.
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Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...
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Changing the needle for lumbar punctures
DEFF Research Database (Denmark)
Engedal, Thorbjørn Søndergaard; Ording, H.; Vilholm, O. J.
2015-01-01
Objective: Post-dural puncture headache (PDPH) is a common complication of diagnostic lumbar punctures. Both a non-cutting needle design and the use of smaller size needles have been shown to greatly reduce the risk of PDPH. Nevertheless, larger cutting needles are still widely used. This study d...
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Uranium solubility and solubility controls in selected Needle's Eye groundwaters
International Nuclear Information System (INIS)
Falck, W.E.; Hooker, P.J.
1992-01-01
The British Geological Survey (BGS) has been co-ordinating a research programme centred on the Needle's Eye natural analogue site in Dumfries and Galloway District, southwest Scotland. This study of a natural radioactive geochemical system has been carried out with the aim of improving confidence in using geochemical and predictive models of radionuclide (uranium) migration in the geosphere. The Needle's Eye site is located on the Solway Coat within the Southwick Coast Reserve of the Scottish Wildlife Trust who gave permission to sample for soils, sediments and waters for analysis. This report is one of a series and covers the period from June 1989 to June 1990. It presents the results of applying the PHREEQE code to the hydrochemistry of the site using the CHEMVAL thermodynamic database. (author)
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Ultrasound-guided, minimally invasive, percutaneous needle puncture treatment for tennis elbow.
Zhu, Jiaan; Hu, Bing; Xing, Chunyan; Li, Jia
2008-10-01
This report evaluates the efficacy of percutaneous needle puncture under sonographic guidance in treating lateral epicondylitis (tennis-elbow). Ultrasound-guided percutaneous needle puncture was performed on 76 patients who presented with persistent elbow pain. Under a local anesthetic and sonographic guidance, a needle was advanced into the calcification foci and the calcifications were mechanically fragmented. This was followed by a local injection of 25 mg prednisone acetate and 1% lidocaine. If no calcification was found then multiple punctures were performed followed by local injection of 25 mg prednisone acetate and 1% lidocaine. A visual analog scale (VAS) was used to evaluate the degree of pain pre-and posttreatment at 1 week to 24 weeks. Elbow function improvement and degree of self-satisfaction were also evaluated. Of the 76 patients, 55% were rated with excellent treatment outcome, 32% good, 11% average, and 3% poor. From 3 weeks posttreatment, VAS scores were significantly reduced compared with the pretreatment score (Ptennis elbow. Sonography can be used to accurately identify the puncture location and monitor changes.
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Energy Technology Data Exchange (ETDEWEB)
Conn, A. R.; Parker, Q. A.; Zucker, D. B. [Department of Physics and Astronomy, Macquarie University, NSW 2109 (Australia); Ibata, R. A.; Martin, N. F. [Observatoire Astronomique, Universite de Strasbourg, CNRS, F-67000 Strasbourg (France); Lewis, G. F. [Sydney Institute for Astronomy, School of Physics, A28, University of Sydney, Sydney, NSW 2006 (Australia); McConnachie, A. W. [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia V9E 2E7 (Canada); Irwin, M. J.; Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Tanvir, N. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Fardal, M. A. [University of Massachusetts, Department of Astronomy, LGRT 619-E, 710 N. Pleasant Street, Amherst, MA 01003-9305 (United States); Ferguson, A. M. N. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Valls-Gabaud, D. [Observatoire de Paris, LERMA, 61 Avenue de l' Observatoire, F-75014 Paris (France)
2012-10-10
In 'A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (Part I)', a new technique was introduced for obtaining distances using the tip of the red giant branch (TRGB) standard candle. Here we describe a useful complement to the technique with the potential to further reduce the uncertainty in our distance measurements by incorporating a matched-filter weighting scheme into the model likelihood calculations. In this scheme, stars are weighted according to their probability of being true object members. We then re-test our modified algorithm using random-realization artificial data to verify the validity of the generated posterior probability distributions (PPDs) and proceed to apply the algorithm to the satellite system of M31, culminating in a three-dimensional view of the system. Further to the distributions thus obtained, we apply a satellite-specific prior on the satellite distances to weight the resulting distance posterior distributions, based on the halo density profile. Thus in a single publication, using a single method, a comprehensive coverage of the distances to the companion galaxies of M31 is presented, encompassing the dwarf spheroidals Andromedas I-III, V, IX-XXVII, and XXX along with NGC 147, NGC 185, M33, and M31 itself. Of these, the distances to Andromedas XXIV-XXVII and Andromeda XXX have never before been derived using the TRGB. Object distances are determined from high-resolution tip magnitude posterior distributions generated using the Markov Chain Monte Carlo technique and associated sampling of these distributions to take into account uncertainties in foreground extinction and the absolute magnitude of the TRGB as well as photometric errors. The distance PPDs obtained for each object both with and without the aforementioned prior are made available to the reader in tabular form. The large object coverage takes advantage of the unprecedented size and photometric depth of the Pan-Andromeda Archaeological Survey
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Determination of metals in scots pine (Pinus Sylvestris) needles and soil samples
International Nuclear Information System (INIS)
Ludborzs, A.; Viksna, A.
2000-01-01
Current report is the finding to apply two modern and powerful methods of microanalysis - Total Reflection X-ray Fluorescence Spectrometry (TXRF) and Graphite Furnace Atomic Absorption Spectrometry - for the analysis of biological and geological materials. For some of the measurements Instrumental Neutron Activation Analysis (INAA) has been used as an arbitrary method. The goal of the research project is to find possible relationships between metals content in the Scots pine (Pinus sylvestris) needles and the soil samples, which have been taken under the trees. The objectives of the work are analysis of both needles and soils, pH measurements of the soil samples, and handling of a simplified metal speciation analysis in the soil samples. For statistical reliability of the project, seven pine trees from different locations in Latvia have been chosen as the analysis objects. Samples of 20 different age class needles have been collected from the trees and 21 soil sample has been sampled under the trees. K, Ca, Mn, Fe, Zn, Rb, Sr, Pb, and Cd content have been analysed in both samples of the needles and the soils. The obtained measurement data have been processed according to the aim of the project. Relevant questions about causal differences of metal concentrations in different age classes of needles, about subtle working principles of the plant's root system, about the role of some elements in the plant's living processes still remain unanswered. (author)
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Analysis of the NovoTwist pen needle in comparison with conventional screw-thread needles.
Aye, Tandy
2011-11-01
Administration of insulin via a pen device may be advantageous over a vial and syringe system. Hofman and colleagues introduce a new insulin pen needle, the NovoTwist, to simplify injections to a small group of children and adolescents. Their overall preferences and evaluation of the handling of the needle are reported in the study. This new needle has the potential to ease administration of insulin via a pen device that may increase both the use of a pen device and adherence to insulin therapy. © 2011 Diabetes Technology Society.
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Development of a device for real-time light-guided vocal fold injection: A preliminary report.
Cha, Wonjae; Ro, Jung Hoon; Wang, Soo-Geun; Jang, Jeon Yeob; Cho, Jae Keun; Kim, Geun-Hyo; Lee, Yeon Woo
2016-04-01
Vocal fold injection is a minimally invasive technique for various vocal fold pathologies. The shortcomings of the cricothyroid (CT) membrane approach are mainly related to invisibility of the injection needle. If localization of the needle tip can be improved during vocal fold injection with the CT approach, the current problems of the technique can be overcome. We have conceptualized real-time light-guided vocal fold injection that enables simultaneous injection under precise localization. In this study, we developed a device for real-time light-guided vocal fold injection and applied it in excised canine larynx. Animal model. A single optic fiber was inserted in an unmodified 25-gauge needle. A designated connector for the device was attached to the needle, the optic fiber, and the syringe. A laser diode module was used as the light source. An ex vivo canine larynx model was used to validate the device. The location of the needle tip was accurately indicated, and the depth from the mucosa could be estimated according to the brightness and size of the red light. The needle was inserted and could be localized in the canine vocal fold by the light of the device. Precise injection at the intended location was easily performed with no manipulation of the device or the needle. Real-time light-guided vocal fold injection might be a feasible and promising technique for treatment of vocal fold pathology. It is expected that this technique can improve the precision of vocal fold injection and expand its indication in laryngology. NA. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.
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Bond, L; Schulz, B; VanMeter, T; Martin, R C G
2017-02-01
Irreversible electroporation (IRE) uses multiple needles and a series of electrical pulses to create pores in cell membranes and cause cell apoptosis. One of the demands of IRE is the precise needle spacing required. Two-dimensional intraoperative ultrasound (2-D iUS) is currently used to measure inter-needle distances but requires significant expertise. This study evaluates the potential of three-dimensional (3-D) image guidance for placing IRE needles and calculating needle spacing. A prospective clinical evaluation of a 3-D needle localization system (Explorer™) was evaluated in consecutive patients from April 2012 through June 2013 for unresectable pancreatic adenocarcinoma. 3-D reconstructions of patients' anatomy were generated from preoperative CT images, which were aligned to the intraoperative space. Thirty consecutive patients with locally advanced pancreatic cancer were treated with IRE. The needle localization system setup added an average of 6.5 min to each procedure. The 3-D needle localization system increased surgeon confidence and ultimately reduced needle placement time. IRE treatment efficacy is highly dependent on accurate needle spacing. The needle localization system evaluated in this study aims to mitigate these issues by providing the surgeon with additional visualization and data in 3-D. The Explorer™ system provides valuable guidance information and inter-needle distance calculations. Copyright © 2016 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.
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Directory of Open Access Journals (Sweden)
vanessa rabbogliatti
2017-05-01
Full Text Available Peribulbar block (PPB has been used in humans as a safer alternative to retrobulbar block (RBB. PBB, depends on the diffusion of anaesthetic solution into the muscle across the connective tissue and it is performed introducing the needle within the extraconal space. The advantages are fewer complications and palpebral akinesia. In Veterinary Medicine few studies describe this technique in dogs (Ahn J 2013 and cats (Shilo-Benjamini et al. 2013. Based on literature the aim of the study is to determinate, in equine specimens, feasibility of inferior PBB with single needle injection, by using contrast medium (CM, and to evaluate thought Computed Tomography (CT the distribution around the optic nerve (degrees. PBB was performed in 6 orbits. The mixture injected consisted of 20 ml of physiological solution and iodinated CM at 25%. Each periorbital area underwent three CT scans. A basal acquisition to assess the needle position before the injection, a second and third scan were performed immediately after injection, and after application of pressure on the periorbital surface area to promote CM diffusion. The needle position was measured from the tip to the optic nerve with a mean distance of 2,27 mm ± 0,28. The mean volume distribution before pressure application was 23,56 cm3 ± 2,58 and after pressure application was 27,56 cm3 ± 4,8. The CM distribution, was defined (Nouvellon et al. 2010 “successful” in 4 orbits (>270° and “inadequate” in 2 orbits (<180°. The present study demonstrates feasibility of inferior PBB by single injection in horses for its simple and practical execution. Inferior PPB is a potential alternative to systemic administration of neuromuscular blocking agents for ophthalmic surgery. However, this approach needs to be evaluate in clinical trials to assess its feasibility and effectiveness in clinical practice for standing procedures.
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Towards easy and reliable AFM tip shape determination using blind tip reconstruction
International Nuclear Information System (INIS)
Flater, Erin E.; Zacharakis-Jutz, George E.; Dumba, Braulio G.; White, Isaac A.; Clifford, Charles A.
2014-01-01
Quantitative determination of the geometry of an atomic force microscope (AFM) probe tip is critical for robust measurements of the nanoscale properties of surfaces, including accurate measurement of sample features and quantification of tribological characteristics. Blind tip reconstruction, which determines tip shape from an AFM image scan without knowledge of tip or sample shape, was established most notably by Villarrubia [J. Res. Natl. Inst. Stand. Tech. 102 (1997)] and has been further developed since that time. Nevertheless, the implementation of blind tip reconstruction for the general user to produce reliable and consistent estimates of tip shape has been hindered due to ambiguity about how to choose the key input parameters, such as tip matrix size and threshold value, which strongly impact the results of the tip reconstruction. These key parameters are investigated here via Villarrubia's blind tip reconstruction algorithms in which we have added the capability for users to systematically vary the key tip reconstruction parameters, evaluate the set of possible tip reconstructions, and determine the optimal tip reconstruction for a given sample. We demonstrate the capabilities of these algorithms through analysis of a set of simulated AFM images and provide practical guidelines for users of the blind tip reconstruction method. We present a reliable method to choose the threshold parameter corresponding to an optimal reconstructed tip shape for a given image. Specifically, we show that the trend in how the reconstructed tip shape varies with threshold number is so regular that the optimal, or Goldilocks, threshold value corresponds with the peak in the derivative of the RMS difference with respect to the zero threshold curve vs. threshold number. - Highlights: • Blind tip reconstruction algorithms have been implemented and augmented to determine the optimal input parameters. • We demonstrate the capabilities of the algorithms using a simulated AFM
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Bigeleisen, Paul E
2017-05-15
Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.
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Laser Generated Leaky Acoustic Waves for Needle Visualization.
Wu, Kai-Wen; Wang, Yi-An; Li, Pai-Chi
2018-04-01
Ultrasound (US)-guided needle operation is usually used to visualize both tissue and needle position such as tissue biopsy and localized drug delivery. However, the transducer-needle orientation is limited due to reflection of the acoustic waves. We proposed a leaky acoustic wave method to visualize the needle position and orientation. Laser pulses are emitted on top of the needle to generate acoustic waves; then, these acoustic waves propagate along the needle surface. Leaky wave signals are detected by the US array transducer. The needle position can be calculated by phase velocities of two different wave modes and their corresponding emission angles. In our experiments, a series of needles was inserted into a tissue mimicking phantom and porcine tissue to evaluate the accuracy of the proposed method. The results show that the detection depth is up to 51 mm and the insertion angle is up to 40° with needles of different diameters. It is demonstrated that the proposed approach outperforms the conventional B-mode US-guided needle operation in terms of the detection range while achieving similar accuracy. The proposed method reveals the potentials for further clinical applications.
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[Theoretical origin and clinical application of wrist-ankle acupuncture therapy].
Wang, Qiong; Zhou, Qinghui
2017-05-12
The theory of wrist-ankle acupuncture is consistent with traditional meridian-collateral theory. For example, the body divisions of wrist-ankle acupuncture are corresponding to the distribution of 12 cutaneous regions of meridians, the needling sites of it are to the running courses of 12 meridians; the indications of it are to those of 12 meridians. The needling sites of wrist-ankle acupuncture are relevant with some special acupoints of acupuncture theory. For example, the 12-needling sites of wrist-ankle acupuncture are located similar to those of 12 meridian points and have very similar indications. The needling sites of it are located in the wrist and ankle regions, in which the five- shu points are located nearby, for meridian disorders. Most luo -connecting points are located near to the needling sites of wrist-ankle acupuncture or the needle tip points to. Additionally, the needling method of wrist-ankle acupuncture is consistent with some of the subcutaneous needling methods in traditional acupuncture therapy. On the basis of the aspects mentioned above, it is explained that wrist-ankle acupuncture is the development of traditional acupuncture and cannot be independent from the traditional theories of acupuncture and meridians. It is necessary to seek for the evidence from the traditional theories of TCM. The traditional theories of TCM are summarized from clinical practice, which can be newly verified from the practice of wrist-ankle acupuncture.
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Directory of Open Access Journals (Sweden)
Xiaoxing Zhang
2012-05-01
Full Text Available A numerical study has been conducted to understand the mutual effect among nearby needles in a multi-needle electrode dielectric barrier discharge. In the present paper, a fluid-hydrodynamic model is adopted. In this model, the mutual effect among nearby needles in a multi-needle configuration of an atmospheric air dielectric barrier discharge are investigated using a fluid-hydrodynamic model including the continuity equations for electrons and positive and negative ions coupled with Poisson’s equation. The electric fields at the streamer head of the middle needle (MN and the side needles (SNs in a three-needle model decreased under the influence of the mutual effects of nearby needles compared with that in the single-needle model. In addition, from the same comparison, the average propagation velocities of the streamers from MN and SNs, the electron average energy profile of MN and SNs (including those in the streamer channel, at the streamer head, and in the unbridged gap, and the electron densities at the streamer head of the MN and SNs also decreased. The results obtained in the current paper agreed well with the experimental and simulation results in the literature.
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Thulium fiber laser lithotripsy using a muzzle brake fiber tip
Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.
2017-02-01
The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.
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Study of DSA-guided percutaneous puncture location of foramen oval
International Nuclear Information System (INIS)
Zhao Xiaojun; He Jiawei; Bai Guanghui; Shi Jianjing; Xu Chongyong; Zhan Gonghao
2008-01-01
Objective: To study the technique of digital substraction angiography (DSA)-guided percutaneous puncture location of foramen oval. Methods: 39 cases of trigeminal neuralgia were included in the study from Feb. 2004 to Oct. 2006. The patients were punctured by the amending anterior position. The f0ramen oval was displayed by moving the tube tilted 20-28 degree to the caudal and 16-23 degree to the healthy side. The direction and depth of the needles was determined on the lateral view. Then, radio-frequency thermocoagulation therapy was performed. Results: The needles were located in oval foramen in all the patients. Pain disappeared in 36 cases, alleviated in other cases, and no serious complication occurred during therapy. Conclusions: Oval foramen locations by DSA can improve the successful rate of operation. The foramen oval can be clearly displayed by DSA-guided in amending position, with comfortable position for patients. (authors)
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Ultrasound probe and needle-guide calibration for robotic ultrasound scanning and needle targeting.
Kim, Chunwoo; Chang, Doyoung; Petrisor, Doru; Chirikjian, Gregory; Han, Misop; Stoianovici, Dan
2013-06-01
Image-to-robot registration is a typical step for robotic image-guided interventions. If the imaging device uses a portable imaging probe that is held by a robot, this registration is constant and has been commonly named probe calibration. The same applies to probes tracked by a position measurement device. We report a calibration method for 2-D ultrasound probes using robotic manipulation and a planar calibration rig. Moreover, a needle guide that is attached to the probe is also calibrated for ultrasound-guided needle targeting. The method is applied to a transrectal ultrasound (TRUS) probe for robot-assisted prostate biopsy. Validation experiments include TRUS-guided needle targeting accuracy tests. This paper outlines the entire process from the calibration to image-guided targeting. Freehand TRUS-guided prostate biopsy is the primary method of diagnosing prostate cancer, with over 1.2 million procedures performed annually in the U.S. alone. However, freehand biopsy is a highly challenging procedure with subjective quality control. As such, biopsy devices are emerging to assist the physician. Here, we present a method that uses robotic TRUS manipulation. A 2-D TRUS probe is supported by a 4-degree-of-freedom robot. The robot performs ultrasound scanning, enabling 3-D reconstructions. Based on the images, the robot orients a needle guide on target for biopsy. The biopsy is acquired manually through the guide. In vitro tests showed that the 3-D images were geometrically accurate, and an image-based needle targeting accuracy was 1.55 mm. These validate the probe calibration presented and the overall robotic system for needle targeting. Targeting accuracy is sufficient for targeting small, clinically significant prostatic cancer lesions, but actual in vivo targeting will include additional error components that will have to be determined.
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Directory of Open Access Journals (Sweden)
Byeong jun Ahn
2015-11-01
Full Text Available Background We hypothesized that the direction of the J-tip of the guidewire during insertion into the internal jugular vein (IJV might determine its ultimate location. Methods In this study, 300 patients between the ages of 18 and 99 years who required central venous catheterization via IJV in the emergency department enrolled for randomization. IVJ catheterization was successful in 285 of 300 patients. An independent operator randomly prefixed the direction of the J-tip of the guidewire to one of three directions. Based on the direction of the J-tip, patients were allocated into three groups: the J-tip medial-directed group (Group A, the lateral-directed group (Group B, or the downward-directed group (Group C. Postoperative chest radiography was performed on all patients in order to visualize the location of the catheter tip. A catheter is considered malpositioned if it is not located in the superior vena cava or right atrium. Results Of the total malpositioned catheter tips (8 of 285; 2.8%, the majority (5 of 8; 62.5% entered the contralateral subclavian vein, 2 (25.0% were complicated by looping, and 1 (12.5% entered the ipsilateral subclavian vein. According to the direction of the J-tip of the guidewire, the incidence of malpositioning of the catheter tip was 4 of 92 in Group A (4.3%, 4 of 96 in Group B (4.2%, and there were no malpositions in Group C. There were no significant differences among the three groups (p = 0.114. Conclusions The direction of the J-tip of the guidewire had no statistically significant effect on incidence of malpositioned tips.
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International Nuclear Information System (INIS)
Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.
1977-01-01
A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)
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Processing and Characterization of Needled Carbon Composites
2015-12-01
needle is used to insert high strength yarns (i.e., threads) through the dry fabric or prepreg laminate , leaving a loose thread loop underneath [9-11...capability which uses commercially-available felting needles to insert z-fibers into composite laminates at different angles (±45/90°) relative to the... laminate plane. Previous work with needled glass/epoxy composites has shown a 270% improvement in Mode I interlaminar fracture toughness when needled
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Evaluation of electrical nerve stimulation for epidural catheter positioning in the dog.
Garcia-Pereira, Fernando L; Sanders, Robert; Shih, Andre C; Sonea, Ioana M; Hauptman, Joseph G
2013-09-01
To evaluate the accuracy of epidural catheter placement at different levels of the spinal cord guided solely by electrical nerve stimulation and resultant segmental muscle contraction. Prospective, experiment. Six male and two female Beagles, age (1 ± 0.17 years) and weight (12.9 ± 1.1 kg). Animals were anesthetized with propofol and maintained with isoflurane. An insulated epidural needle was used to reach the lumbosacral epidural space. A Tsui epidural catheter was inserted and connected to a nerve stimulator (1.0 mA, 0.1 ms, 2 Hz) to assess positioning of the tip at specific spinal cord segments. The catheter was advanced to three different levels of the spinal cord: lumbar (L2-L5), thoracic (T5-T10) and cervical (C4-C6). Subcutaneous needles were previously placed at these spinal levels and the catheter was advanced to match the needle location, guided only by corresponding muscle contractions. Catheter position was verified by fluoroscopy. If catheter tip and needle were at the same vertebral body a score of zero was assigned. When catheter tip was cranial or caudal to the needle, positive or negative numbers, respectively, corresponding to the number of vertebrae between them, were assigned. The mean and standard deviation of the number of vertebrae between catheter tip and needle were calculated to assess accuracy. Results are given as mean ± SD. The catheter position in relation to the needle was within 0.3 ± 2.0 vertebral bodies. Positive predictive values (PPV) were 57%, 83% and 71% for lumbar, thoracic and cervical regions respectively. Overall PPV was 70%. No significant difference in PPV among regions was found. Placement of an epidural catheter at specific spinal levels using electrical nerve stimulation was feasible without radiographic assistance in dogs. Two vertebral bodies difference from the target site may be clinically acceptable when performing segmental epidural regional anesthesia. © 2013 Association of Veterinary
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The research of knitting needle status monitoring setup
Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie
2013-09-01
In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.
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International Nuclear Information System (INIS)
Kang, Seung Hee; Chun, Mi Son; Kang, Hae Jin; Jung, Chil; Son, Jeong Hyae
1998-01-01
It is not a simple task to achieve the ideal isodose curve with a standard vaginal applicator or single plane needle impant in the paravaginal tissue when primary or recurrent gynecological neoplasms(cervical cancers, vaginal cancers and vulvar cancers) are treated as a boost following external beam radiotherapy. The authors introduce the development and construction of a simple, inexpensive, customized applicator for volume implant to maximize the radiation dose to the tumor while minimizing the dose to the rectum and the bladder. Nine patients underwent Ir-192 transperineal interstitial implantation for either recurrent(5 cases)or primary(3 cases) cervical cancers or primary vaginal cancer(1 case) between August 1994 and February 1998 at Ajou university hospital. First 3 cases were performed with a single plane implant guided by digital palpation. Because of inadequate isodose coverage in the tumor volume in first 3 cases, we designed and constructed interstitial vaginal applicator for volume implant to mprove tumor dose distribution and homogeneity while sparing the surrounding normal tissue. Our applicators consist of vaginal obturator and perineal template that made of the clear acrylamide and dental mold material(Provil). The applicators were customized individually according to the tumor size and its location. Both HDR and LDR irradiation were given with these applicators accomodating 6 Fr needles(Microselectron, Nucletron). The pretreatment planning prior to actual implant was performed whenever possible. Needles can be inserted easily and evenly into the tumor volume through the holes of templates, requiring less efforts and time for the implant prodecure. Our applicators made of materials available from commercial vendors. These have an advantage that require easy procedure, and spend relatively short time to construct. Also it was possible to fabricate applicators to individualize according to the tumor size and its location and to achieve the ideal
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Needle thoracostomy in the treatment of a tension pneumothorax in trauma patients: what size needle?
Zengerink, Imme; Brink, Peter R; Laupland, Kevin B; Raber, Earl L; Zygun, Dave; Kortbeek, John B
2008-01-01
A tension pneumothorax requires immediate decompression using a needle thoracostomy. According to advanced trauma life support guidelines this procedure is performed in the second intercostal space (ICS) in the midclavicular line (MCL), using a 4.5-cm (2-inch) catheter (5-cm needle). Previous studies have shown a failure rate of up to 40% using this technique. Case reports have suggested that this high failure rate could be because of insufficient length of the needle. To analyze the average chest wall thickness (CWT) at the second ICS in the MCL in a trauma population and to evaluate the length of the needle used in needle thoracostomy for emergency decompression of tension pneumothoraces. Retrospective review of major trauma admissions (Injury Severity Score >12) at the Foothills Medical Centre in Calgary, Canada, who underwent a computed tomography chest scan admitted in the period from October 2001 until March 2004. Subgroup analysis on men and women, /=40 years of age was defined a priori. CWT was measured to the nearest 0.01 cm at the second ICS in the MCL. The mean CWT in the 604 male patients and 170 female patients studied averaged 3.50 cm at the left second ICS MCL and 3.51 cm on the right. The mean CWT was significantly higher for women than men (p 4.5 cm and 24.1% to 35.4% of the women studied. A catheter length of 4.5 cm may not penetrate the chest wall of a substantial amount (9.9%-35.4%) of the population, depending on age and gender. This study demonstrates the need for a variable needle length for relief of a tension pneumothorax in certain population groups to improve effectiveness of needle thoracostomy.
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Singh, Kunwar Pal
2016-10-12
The ion current rectification has been obtained as a function of the location of a heterojunction in a bipolar conical nanopore fluidic diode for different parameters to determine the junction location for maximum ion current rectification using numerical simulations. Forward current peaks for a specific location of the junction and reverse current decreases with the junction location due to a change in ion enrichment/depletion in the pore. The optimum location of the heterojunction shifts towards the tip with base/tip diameter and surface charge density, and towards the base with the electrolyte concentration. The optimum location of the heterojunction has been approximated by an equation as a function of pore length, base/tip diameter, surface charge density and electrolyte concentration. The study is useful to design a rectifier with maximum ion current rectification for practical purposes.
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Investigations of needle-free jet injections.
Schramm-Baxter, J R; Mitragotri, S
2004-01-01
Jet injection is a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers drugs. Although a number of jet injectors are commercially available, especially for insulin delivery, they have a low market share compared to needles possibly due to occasional pain associated with jet injection. Jets employed by the traditional jet injectors penetrate deep into the dermal and sub-dermal regions where the nerve endings are abundantly located. To eliminate the pain associated with jet injections, we propose to utilize microjets that penetrate only into the superficial region of the skin. However, the choice of appropriate jet parameters for this purpose is challenging owing to the multiplicity of factors that determine the penetration depth. Here, we describe the dependence of jet injections into human skin on the power of the jet. Dermal delivery of liquid jets was quantified using two measurements, penetration of a radiolabeled solute, mannitol, into skin and the shape of jet dispersion in the skin which was visualized using sulforhodamine B. The dependence of the amount of liquid delivered in the skin and the geometric measurements of jet dispersion on nozzle diameter and jet velocity was captured by a single parameter, jet power.
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Laan, Danuel V; Vu, Trang Diem N; Thiels, Cornelius A; Pandian, T K; Schiller, Henry J; Murad, M Hassan; Aho, Johnathon M
2016-04-01
Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78-46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70-51.00) at MAL, and 34.33 mm (95% CI, 28.20-40.47) at AAL (P=.08). Mean failure rate was 38% (95% CI, 24-54) at 2nd ICS-MCL, 31% (95% CI, 10-64) at MAL, and 13% (95% CI, 8-22) at AAL (P=.01). Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. Level 3 SR/MA with up to two negative criteria. Therapeutic. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Sung, Si Yoon; Kwon, Jong Won [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)
2015-11-15
To evaluate the variable factors affecting the results of percutaneous needle biopsies for infectious spondylitis. In all, 249 patients who underwent both MRI and percutaneous needle biopsies due to a suspicion of infectious spondylitis were evaluated with respect to the following factors: the usage of antibiotics before the procedure, the location of the biopsy, the guiding equipment used, the experience level of the operators, and the number of biopsies performed. The positivity of culture in cases of treated with antibiotics (16.3%) before the biopsy was lower than in the untreated cases (30.5%) (p = 0.004). Biopsies performed at the abscess (43.5%) and with fluoroscopic guidance (27.8%) showed higher culture positivity as well. The experience level of the operators and the number of biopsies had no effect on culture positivity. The usage of antibiotics before the biopsy, the biopsy's location, and the guiding equipment used affect the culture positivity, while the experience levels of the operators and the number of biopsies do not have an effect.
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International Nuclear Information System (INIS)
Sung, Si Yoon; Kwon, Jong Won
2015-01-01
To evaluate the variable factors affecting the results of percutaneous needle biopsies for infectious spondylitis. In all, 249 patients who underwent both MRI and percutaneous needle biopsies due to a suspicion of infectious spondylitis were evaluated with respect to the following factors: the usage of antibiotics before the procedure, the location of the biopsy, the guiding equipment used, the experience level of the operators, and the number of biopsies performed. The positivity of culture in cases of treated with antibiotics (16.3%) before the biopsy was lower than in the untreated cases (30.5%) (p = 0.004). Biopsies performed at the abscess (43.5%) and with fluoroscopic guidance (27.8%) showed higher culture positivity as well. The experience level of the operators and the number of biopsies had no effect on culture positivity. The usage of antibiotics before the biopsy, the biopsy's location, and the guiding equipment used affect the culture positivity, while the experience levels of the operators and the number of biopsies do not have an effect
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A novel needle-type sampling device for flexible ultrathin bronchoscopy
International Nuclear Information System (INIS)
Suda, Yuji; Hayashi, Katsutoshi; Shindoh, Yuriko; Iijima, Hideya; Tanaka, Akiko
2008-01-01
Diagnosis of suspected cancer in the periphery of the lung is difficult. A flexible ultrathin bronchoscope has been developed for the diagnosis of peripherally located pulmonary lesions that cannot be reached with the sampling devices for standard flexible bronchoscopes. The diagnostic yield with forceps and a brush for ultrathin bronchoscopes, however, is not adequate, especially when a lesion is not exposed to the bronchial lumen. We have thus developed a novel needle-type sampling device and tested its yield in transbronchial cytology. The device consists of an elongated dental H-file (0.4 mm in diameter and 110 cm in length), a housing sheath (1.0 mm in outer diameter), and a novel handle, which enables rapid out-and-in motion of the needle. Ten consecutive patients with a peripheral pulmonary lesion who had an indication for diagnostic procedure with a flexible ultrathin bronchoscope were enrolled. The optimal bronchial route to the lesion was analyzed with virtual bronchoscopy in a data set obtained with high-resolution computed tomography, and a novel bronchial route labeling system (prior-ridge-based relative orientation nomenclature) was employed to guide insertion of the bronchoscope. Sampling with the novel needle was performed prior to use of the forceps and brush under conventional fluoroscopy. In all the cases, sampling with the needle was successful and the amount of the specimen was sufficient for cytology. Our novel sampling system with flexible ultrathin bronchoscopes may contribute to accurate and minimally invasive diagnosis of peripheral pulmonary lesions. (author)
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Fine needle aspiration cytology of parapharyngeal tumors
Directory of Open Access Journals (Sweden)
Mondal Palash
2009-01-01
Full Text Available Background: Parapharyngeal tumors are rare and often pose diagnostic difficulties due to their location and plethora of presentations. Objectives: The study was undertaken to study the occurrence in the population and to evaluate the exact nature by fine needle aspiration cytology (FNAC. Materials and Methods: A total of five hundred and six cases of lateral neck lesions were studied over three and half years. Of these 56 suspected parapharyngeal masses were selected by clinical and radiological methods. Cytopathology evaluation was done by fine needle aspiration cytology with computed tomography and ultrasonography guidance wherever necessary. Histopathology confirmation was available in all the cases. Results: On FNAC diagnosis could be established in 54 cases while in two cases the material was insufficient to establish a diagnosis. The tumors encountered were, pleomorphic adenoma (33, schwannoma (3, neurofibroma (11, paraganglioma (5, angiofibroma (1 and adenoid cystic carcinoma (1. Four false positives and two false negative cases were encountered. Overall sensitivity was 96%, with specificity of 99% and accuracy being 98.8%. Conclusions: With proper clinical and radiological assessment, FNAC can be extremely useful in diagnosing most of these lesions except a few which need histopathological and even immunohistochemical confirmation.
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Experiences with a new breast localisation needle
International Nuclear Information System (INIS)
Hergan, K.; Amann, T.; Doringer, W.; Hollenstein, P.
1990-01-01
In view of the increasing number of biopsies of non-palpable lesions of the female breast we found an ideal localisation system in the Hawkins breast localisation needle. Localisation was successful without technical problems in 31 out of 34 patients. The special advantages of the needle are its stability in position and excellent manoeverability due to the construction of the needle. The very simple handling of the needle is an advantage not only for the radiologist but also for the surgeon. (orig.) [de
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Influence of the tip mass on the tip-sample interactions in TM-AFM
Energy Technology Data Exchange (ETDEWEB)
Pishkenari, Hossein Nejat, E-mail: nejat@mech.sharif.edu [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of); Meghdari, Ali [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of)
2011-07-15
This paper focuses on the influences of the tip mass ratio (the ratio of the tip mass to the cantilever mass), on the excitation of higher oscillation eigenmodes and also on the tip-sample interaction forces in tapping mode atomic force microscopy (TM-AFM). A precise model for the cantilever dynamics capable of accurate simulations is essential for the investigation of the tip mass effects on the interaction forces. In the present work, the finite element method (FEM) is used for modeling the AFM cantilever to consider the oscillations of higher eigenmodes oscillations. In addition, molecular dynamics (MD) is used to calculate precise data for the tip-sample force as a function of tip vertical position with respect to the sample. The results demonstrate that in the presence of nonlinear tip-sample interaction forces, the tip mass ratio plays a significant role in the excitations of higher eigenmodes and also in the normal force applied on the surface. Furthermore, it has been shown that the difference between responses of the FEM and point-mass models in different system operational conditions is highly affected by the tip mass ratio. -- Highlights: {yields} A strong correlation exists between the tip mass ratio and the 18th harmonic amplitude. {yields} Near the critical tip mass ratio a small change in the tip mass may lead to a significant force change. {yields} Inaccuracy of the lumped model depends significantly on the tip mass ratio.
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21 CFR 868.5150 - Anesthesia conduction needle.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient to...
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Freehand biopsy guided by electromagnetic needle tracking
DEFF Research Database (Denmark)
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
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Jiang, Jun-Hong; Turner, J Francis; Huang, Jian-An
2015-12-01
TBNA through the flexible bronchoscope is a 37-year-old technology that utilizes a TBNA needle to puncture the bronchial wall and obtain specimens of peribronchial and mediastinal lesions through the flexible bronchoscope for the diagnosis of benign and malignant diseases in the mediastinum and lung. Since 2002, the Olympus Company developed the first generation ultrasound equipment for use in the airway, initially utilizing an ultrasound probe introduced through the working channel followed by incoroporation of a fixed linear ultrasound array at the distal tip of the bronchoscope. This new bronchoscope equipped with a convex type ultrasound probe on the tip was subsequently introduced into clinical practice. The convex probe (CP)-EBUS allows real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) of mediastinal and hilar lymph nodes. EBUS-TBNA is a minimally invasive procedure performed under local anesthesia that has been shown to have a high sensitivity and diagnostic yield for lymph node staging of lung cancer. In 10 years of EBUS development, the Olympus Company developed the second generation EBUS bronchoscope (BF-UC260FW) with the ultrasound image processor (EU-M1), and in 2013 introduced a new ultrasound image processor (EU-M2) into clinical practice. FUJI company has also developed a curvilinear array endobronchial ultrasound bronchoscope (EB-530 US) that makes it easier for the operator to master the operation of the ultrasonic bronchoscope. Also, the new thin convex probe endobronchial ultrasound bronchoscope (TCP-EBUS) is able to visualize one to three bifurcations distal to the current CP-EBUS. The emergence of EBUS-TBNA has also been accompanied by innovation in EBUS instruments. EBUS elastography is, then, a new technique for describing the compliance of structures during EBUS, which may be of use in the determination of metastasis to the mediastinal and hilar lymph nodes. This article describes these new EBUS
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Benham, Alex; Johnson, Mark I
2014-06-01
There is insufficient evidence of a relationship between acupuncture needle sensations (de qi) and hypoalgesia. The aim of this study was to investigate the effects of bidirectional needle rotation at LI10 on acupuncture needle sensations and heat pain thresholds. Twenty-two healthy participants received one acupuncture needle at LI10 with bidirectional rotation of the needle in one experimental session and one acupuncture needle at LI10 with mock rotation in a separate session, in a randomised order. Measurements of heat pain thresholds were taken before needle insertion, during needle retention and 15 min after needle removal. At each measurement time point, participants rated needle sensations using the Massachusetts Acupuncture Sensation Scale (MASS) and a visual analogue scale (VAS) of overall intensity of needle sensation. Bidirectional needle rotation produced significantly higher scores for VAS, MASStotal, MASSpain and MASSsensation compared with mock rotation (all psensation and change in pain threshold after needling was only found when data from mock and rotation interventions were combined. Needle rotation increases the magnitude of hypoalgesia. There is tentative evidence that needle sensation may be associated with the amount of change in pain threshold. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
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International Nuclear Information System (INIS)
Fujita, Yuzo
1977-01-01
Needle counter had been devised by Geiger about 60 years ago before the present GM counter appeared. It is suitable for the detection of weak radiation because it is limited in effective volume, if the background due to mainly cosmic ray is proportional to the effective volume of the counter. Recently the very low β detector having a needle counter as the main detector has been developed. It showed highly excellent performance in the measurements of small area samples, about ten times sensitive as compared with other detectors. The counter is installed in the very low radiation measuring well at Nokogiriyama, Chiba Prefecture, using a NaI scintillator as its guard counter. D. H. Wilkinson first treated a gas amplification counter theoretically and quantitatively. The authors have obtained good results in the comparison with the experiments of the counter using a generalized form of Wilkinson theory. The findings obtained through this study seem to be applicable to the electrode arrangement which is important for the counter design. It was found that the excellent rise time of induced pulses in a gas amplification counter was achieved in larger amplification factor and smaller convolution effect. In the detection of charged particles with small obstructing capability such as γ ray, faster rise time and higher pulses can be obtained with needle counters than wire counters. (Wakatsuki, Y.)
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Green Compact Temperature Evolution during Current-Activated Tip-Based Sintering (CATS of Nickel
Directory of Open Access Journals (Sweden)
Khaled Morsi
2013-04-01
Full Text Available Current-activated tip-based sintering (CATS is a novel process where spark plasma sintering conditions are applied through an electrically conducting tip on a locally controlled area on a green powder compact/bed. The localization of electric current in CATS allows for unique temporal and spatial current and temperature distributions within the tip and powder compact. In this paper, special experimental setups were used to monitor the temperature profiles in the tip and at multiple locations on the surface of nickel powder compacts. A variation in the initial green density was found to have a significant effect on the maximum temperature in the tip as well as the temperature distribution across the powder compact. In general, the lowest green density specimens displayed the best conditions for localized densification. The concept of effective current density is introduced and results are discussed in relation to the densification parameter.
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Current status of core needle biopsy of the thyroid
Energy Technology Data Exchange (ETDEWEB)
Baek, Jung Hwan [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)
2017-04-15
Thyroid nodules are a common clinical problem. Fine-needle aspiration (FNA) and large-needle biopsy have been used to diagnose thyroid nodules. Before the 1980s, large-needle biopsy was the standard procedure for the thyroid, but FNA became the standard diagnostic tool in the 1980s because it is a safe procedure that leads to accurate diagnoses. With advances in core needle biopsy (CNB) devices (i.e., spring-activated core needles) and development of high-resolution ultrasound, it has become possible to make accurate diagnoses while minimizing complications. Although 18- to 21-gauge core needles can be used to biopsy thyroid nodules, 18-gauge needles are most commonly used in Korea. The relationships among the size of the needle, the number of core specimens, and diagnostic accuracy have not yet been conclusively established, but the general tendency is that thinner needles cause less damage to the normal thyroid, but allow a smaller amount of thyroid tissue to be biopsied to be obtained. These relationships may be validated in the future.
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Dual-tip magnetic force microscopy with suppressed influence on magnetically soft samples
International Nuclear Information System (INIS)
Precner, Marián; Fedor, Ján; Šoltýs, Ján; Cambel, Vladimír
2015-01-01
Standard magnetic force microscopy (MFM) is considered as a powerful tool used for magnetic field imaging at nanoscale. The method consists of two passes realized by the magnetic tip. Within the first one, the topography pass, the magnetic tip directly touches the magnetic sample. Such contact perturbs the magnetization of the sample explored. To avoid the sample touching the magnetic tip, we present a new approach to magnetic field scanning by segregating the topological and magnetic scans with two different tips located on a cut cantilever. The approach minimizes the disturbance of sample magnetization, which could be a major problem in conventional MFM images of soft magnetic samples. By cutting the cantilever in half using the focused ion beam technique, we create one sensor with two different tips—one tip is magnetized, and the other one is left non-magnetized. The non-magnetized tip is used for topography and the magnetized one for the magnetic field imaging. The method developed we call dual-tip magnetic force microscopy (DT-MFM). We describe in detail the dual-tip fabrication process. In the experiments, we show that the DT-MFM method reduces significantly the perturbations of the magnetic tip as compared to the standard MFM method. The present technique can be used to investigate microscopic magnetic domain structures in a variety of magnetic samples and is relevant in a wide range of applications, e.g., data storage and biomedicine. (paper)
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Full Text Available ... death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ... tv tip-overs. The force of a large television falling from tipping furniture can be staggering. A ...
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Full Text Available ... and furniture, appliance and tv tip-overs. The force of a large television falling from tipping furniture ... 50 lb. TV falls with about the same force as child falling from the third story of ...
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Full Text Available ... Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ... about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of a ...
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Cuijpers, C.F.
2015-01-01
The transjugular intrahepatic portosystemic shunt (TIPS) procedure is one of the most technically challenging procedures in interventional radiology. During the procedure, interventional radiologists (IRs) insert very thin and long instruments through a little incision in the patient’s neck. They
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... now Try it free Find out why Close CPAP Tips from FDA USFoodandDrugAdmin Loading... Unsubscribe from USFoodandDrugAdmin? ... apnea and use a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from ...
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International Nuclear Information System (INIS)
Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A; Senneville, B Denis de; Hautvast, G; Binnekamp, D
2015-01-01
Purpose: To develop adaptive planning with feedback for MRI-guided focal HDR prostate brachytherapy with a single divergent needle robotic implant device. After each needle insertion, the dwell positions for that needle are calculated and the positioning of remaining needles and dosimetry are both updated based on MR imaging. Methods: Errors in needle positioning may occur due to inaccurate needle insertion (caused by e.g. the needle’s bending) and unpredictable changes in patient anatomy. Consequently, the dose plan quality might dramatically decrease compared to the preplan. In this study, a procedure was developed to re-optimize, after each needle insertion, the remaining needle angulations, source positions and dwell times in order to obtain an optimal coverage (D95% PTV>19 Gy) without exceeding the constraints of the organs at risk (OAR) (D10% urethra<21 Gy, D1cc bladder<12 Gy and D1cc rectum<12 Gy). Complete HDR procedures with 6 needle insertions were simulated for a patient MR-image set with PTV, prostate, urethra, bladder and rectum delineated. Random angulation errors, modeled by a Gaussian distribution (standard deviation of 3 mm at the needle’s tip), were generated for each needle insertion. We compared the final dose parameters for the situations (I) without re-optimization and (II) with the automatic feedback. Results: The computation time of replanning was below 100 seconds on a current desk computer. For the patient tested, a clinically acceptable dose plan was achieved while applying the automatic feedback (median(range) in Gy, D95% PTV: 19.9(19.3–20.3), D10% urethra: 13.4(11.9–18.0), D1cc rectum: 11.0(10.7–11.6), D1cc bladder: 4.9(3.6–6.8)). This was not the case without re-optimization (median(range) in Gy, D95% PTV: 19.4(14.9–21.3), D10% urethra: 12.6(11.0–15.7), D1cc rectum: 10.9(8.9–14.1), D1cc bladder: 4.8(4.4–5.2)). Conclusion: An automatic guidance strategy for HDR prostate brachytherapy was developed to compensate
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Pine needle abortion biomarker detected in bovine fetal fluids
Pine needle abortion is a naturally occurring condition in free-range cattle caused by the consumption of pine needles from select species of cypress, juniper, pine, and spruce trees. Confirmatory diagnosis of pine needle abortion has previously relied on a combined case history of pine needle cons...
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Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...
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STUDY & ANALYSIS OF MICRO NEEDLE MATERIAL BY ANSYS
Santosh Kumar Singh*, Prabhat Sinha, N.N. Singh, Nagendra Kumar
2017-01-01
In this research the concept of design and analysis, silicon and stainless steel based on hollow micro-needles for transdermal drug delivery(TDD) have been evaluated by Using ANSYS & computational fluid dynamic (CFD), structural. Micro fluidic analysis has performed to ensure the micro-needles design suitability for Drug delivery. The effect of axial and transverse load on single and micro-needle array has investigated with the mechanical properties of micro-needle. The analysis predicte...
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Full Text Available ... now Try it free Find out why Close CPAP Tips from FDA USFoodandDrugAdmin Loading... Unsubscribe from USFoodandDrugAdmin? ... apnea and use a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from ...
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International Nuclear Information System (INIS)
Jung, Sung Hwa; Park, Won Kyu; Chang, Jay Chun; Kim, Jae Woon; Cho, Jae Ho; Jang, Han Won; Lee, Jae Kyo; Choi, Joon Hyuk
2008-01-01
The objective of this study is to evaluate the efficacy and safety of an ultrasound-guided core needle biopsy with an 18G cutting needle in patients suspected of having a pancreatic disease by analyzing the diagnostic performance and complication rate. The study population comprised 35 consecutive patients who underwent an ultrasound-guided core needle biopsy using a high-speed biopsy gun accompanied with an 18G cutting-type needle between May of 2001 and October of 2005. The diagnostic performance (i.e., the acquisition rate and diagnostic accuracy) and complications associated with core needle biopsies were evaluated for its efficacy and safety. Thirty-six sessions of ultrasound-guided core needle biopsies were performed in 35 consecutive patients. All patients, except two (serous cystadenoma and autoimmune pancreatitis) were diagnosed with various subtypes of pancreatic cancer. The acquisition rate and diagnostic accuracy were 97% (35/36) and 94% (34/36), respectively. A complication occurred only in one patient (3%), which further proved to be a delayed complication (i.e., needle tract implantation). According to our findings, the ultrasound-guided core needle biopsy is a viable and safe method for the diagnosis of pancreatic diseases. Moreover, it enables the diagnosis of the pancreatic cancer subtype
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NPIP: A skew line needle configuration optimization system for HDR brachytherapy
International Nuclear Information System (INIS)
Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtürk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean
2012-01-01
Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, δ. The candidate needle set consisted of 5000 needles, and a range of δ values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of δ values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer
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Naganobu, Kiyokazu; Hagio, Mitsuyoshi
2007-01-01
To assess the accuracy of the 'hanging drop method' for identifying the extradural space in anaesthetized dogs positioned in sternal or lateral recumbency. Prospective randomized-experimental study. Seventeen clinically healthy adult dogs, 10 females and seven males weighing 8.4-26.2 kg. Dogs were positioned in either sternal (n = 8) or lateral (n = 9) recumbency under general anaesthesia. A 20 SWG spinal needle pre-filled with 0.9% saline was advanced through the skin into the lumbosacral extradural space and the response of the saline drop recorded, i.e. whether it: 1) was aspirated from the hub into the needle; 2) remained within the hub, or 3) moved synchronously with i) spontaneous respiration, ii) heart beat or iii) manual lung inflation. The position of the needle tip was ultimately determined by positive contrast radiography. One dog positioned in lateral recumbency was excluded from the study because bleeding occurred from the needle hub. Saline was aspirated into the needle in seven of eight dogs held in sternal recumbency but in none of the dogs positioned in lateral recumbency. Accurate needle tip placement in the extradural space was confirmed by positive contrast radiography in all dogs. The 'hanging drop' method, when performed with a spinal needle, appears to be a useful technique for identifying the location of the extradural space in anaesthetized medium-sized dogs positioned in sternal, but not in lateral recumbency. The technique may yield 'false negative' results when performed in dogs positioned in sternal recumbency.
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Medically relevant ElectroNeedle technology development.
Energy Technology Data Exchange (ETDEWEB)
Schmidt, Carrie Frances; Thomas, Michael Loren; McClain, Jaime L.; Harper, Jason C.; Achyuthan, Komandoor E.; Ten Eyck, Gregory A.
2008-11-01
ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology.
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Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...
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Migration of innumerable chronically retained acupuncture needles
Directory of Open Access Journals (Sweden)
Frances Lazarow, MD
2017-09-01
Full Text Available We present a case of a 50-year-old female with a 2-day history of back and abdominal pain who was discovered to have innumerable chronically retained acupuncture needles, which had migrated throughout her abdomen and pelvis. Although many of these needles were in precarious positions, including the epidural space, renal parenchyma, small bowel, and vasculature, there was no evidence for acute injury. We also briefly discuss evidence for the magnetic resonance imaging compatibility of acupuncture needles. Although a rare complication, given the high frequency of acupuncture therapy in the United States, physicians must be aware of the potential for retained and migrated needles.
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Needle muscle biopsy and its application
Directory of Open Access Journals (Sweden)
Meng-long CHEN
2015-07-01
Full Text Available Needle muscle biopsy is a straightforward and reliable minimally-invasive technique. During the past century, the needle biopsy can provide adequate samples and the technique has gradually gained wider acceptance. Compared with open biopsy, needle biopsy is less traumatic, with low rate of complications, and is suitable for the identifications and evaluations of muscular dystrophy, inflammatory myopathies and systemic diseases involving muscles, specially for infants and young children. Domestic insiders should be encouraged to apply this technique. DOI: 10.3969/j.issn.1672-6731.2015.06.003
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Needle placement accuracy during stereotactic localization mammography
International Nuclear Information System (INIS)
Green, D.H.
2009-01-01
Aim: To derive a mathematical model to describe the relationship between lesion position in the breast and measurements derived from the stereoradiographs to enable more accurate sampling of a lesion during stereotactic mammographic needle placement. Materials and methods: The affect that registration errors have on the accuracy of needle placement when identifying the lesion on the stereoradiographs was investigated using the mathematical model. Results: The focus-to-film distance of the x-ray tube and the horizontal distance of the lesion from the centre of rotation have little effect on error. Registration errors for lesions lying at a greater perpendicular distance in the breast from the centre of rotation produce smaller localization errors when compared with lesions sited closer. Lesion registration errors during marking of the stereoradiographs are exacerbated by decreasing the angle of x-ray tube swing. Conclusions: When problems are encountered in making an accurate registration of the lesion on the stereoradiographs, consider the following error reducing strategies: (1) employ an approach that places the lesion the maximum distance away from the film cassette; (2) avoid reducing the angle of tube swing; and (3) consider sampling superficial and deep to, as well as at, the location indicated. The possibility of erroneous tissue sampling should be borne in mind when reviewing the pathology report.
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Numerical investigation of tip clearance cavitation in Kaplan runners
Nikiforova, K.; Semenov, G.; Kuznetsov, I.; Spiridonov, E.
2016-11-01
There is a gap between the Kaplan runner blade and the shroud that makes for a special kind of cavitation: cavitation in the tip leakage flow. Two types of cavitation caused by the presence of clearance gap are known: tip vortex cavitation that appears at the core of the rolled up vortex on the blade suction side and tip clearance cavitation that appears precisely in the gap between the blade tip edge and the shroud. In the context of this work numerical investigation of the model Kaplan runner has been performed taking into account variable tip clearance for several cavitation regimes. The focus is put on investigation of structure and origination of mechanism of cavitation in the tip leakage flow. Calculations have been performed with the help of 3-D unsteady numerical model for two-phase medium. Modeling of turbulent flow in this work has been carried out using full equations of Navier-Stokes averaged by Reynolds with correction for streamline curvature and system rotation. For description of this medium (liquid-vapor) simplification of Euler approach is used; it is based on the model of interpenetrating continuums, within the bounds of this two- phase medium considered as a quasi-homogeneous mixture with the common velocity field and continuous distribution of density for both phases. As a result, engineering techniques for calculation of cavitation conditioned by existence of tip clearance in model turbine runner have been developed. The detailed visualization of the flow was carried out and vortex structure on the suction side of the blade was reproduced. The range of frequency with maximum value of pulsation was assigned and maximum energy frequency was defined; it is based on spectral analysis of the obtained data. Comparison between numerical computation results and experimental data has been also performed. The location of cavitation zone has a good agreement with experiment for all analyzed regimes.
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Scali, M.; Pusch, T.P.; Breedveld, P.; Dodou, D.
2017-01-01
High accuracy and precision in reaching target locations inside the human body is necessary for the success of percutaneous procedures, such as tissue sample removal (biopsy), brachytherapy, and localized drug delivery. Flexible steerable needles may allow the surgeon to reach targets deep inside
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... needle (a special long needle extending from the neck into the liver). A stent is then placed ... the procedure include: fever muscle stiffness in the neck bruising on the neck at the point of ...
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The tipping point: A mathematical model for the profit-driven abandonment of restaurant tipping
Clifton, Sara M.; Herbers, Eileen; Chen, Jack; Abrams, Daniel M.
2018-02-01
The custom of voluntarily tipping for services rendered has gone in and out of fashion in America since its introduction in the 19th century. Restaurant owners that ban tipping in their establishments often claim that social justice drives their decisions, but we show that rational profit-maximization may also justify the decisions. Here, we propose a conceptual model of restaurant competition for staff and customers, and we show that there exists a critical conventional tip rate at which restaurant owners should eliminate tipping to maximize profits. Because the conventional tip rate has been increasing steadily for the last several decades, our model suggests that restaurant owners may abandon tipping en masse when that critical tip rate is reached.
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Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats
International Nuclear Information System (INIS)
Issy, A.C.; Castania, V.; Castania, M.; Salmon, C.E.G.; Nogueira-Barbosa, M.H.; Bel, E. Del; Defino, H.L.A.
2013-01-01
Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration
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Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats
Energy Technology Data Exchange (ETDEWEB)
Issy, A.C.; Castania, V.; Castania, M. [Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Salmon, C.E.G. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Nogueira-Barbosa, M.H. [Divisão de Radiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Bel, E. Del [Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Defino, H.L.A. [Departamento de Biomecânica, Medicina e Reabilitação do Sistema Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)
2013-03-15
Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration.
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Gravett, Matthew; Cepek, Jeremy; Fenster, Aaron
2017-11-01
The purpose of this study was to develop and validate an image-guided robotic needle delivery system for accurate and repeatable needle targeting procedures in mouse brains inside the 12 cm inner diameter gradient coil insert of a 9.4 T MR scanner. Many preclinical research techniques require the use of accurate needle deliveries to soft tissues, including brain tissue. Soft tissues are optimally visualized in MR images, which offer high-soft tissue contrast, as well as a range of unique imaging techniques, including functional, spectroscopy and thermal imaging, however, there are currently no solutions for delivering needles to small animal brains inside the bore of an ultra-high field MR scanner. This paper describes the mechatronic design, evaluation of MR compatibility, registration technique, mechanical calibration, the quantitative validation of the in-bore image-guided needle targeting accuracy and repeatability, and demonstrated the system's ability to deliver needles in situ. Our six degree-of-freedom, MR compatible, mechatronic system was designed to fit inside the bore of a 9.4 T MR scanner and is actuated using a combination of piezoelectric and hydraulic mechanisms. The MR compatibility and targeting accuracy of the needle delivery system are evaluated to ensure that the system is precisely calibrated to perform the needle targeting procedures. A semi-automated image registration is performed to link the robot coordinates to the MR coordinate system. Soft tissue targets can be accurately localized in MR images, followed by automatic alignment of the needle trajectory to the target. Intra-procedure visualization of the needle target location and the needle were confirmed through MR images after needle insertion. The effects of geometric distortions and signal noise were found to be below threshold that would have an impact on the accuracy of the system. The system was found to have negligible effect on the MR image signal noise and geometric distortion
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Usefulness of fluoroscopy-guided intra-articular injection of the knee
Energy Technology Data Exchange (ETDEWEB)
Myung, Jae Sung; Lee, Joon Woo [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Lee, Ji Yeon [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)] (and others)
2007-06-15
To determine the accuracy of the intra-articular location of hyaluronic acid injection using a blind approach and to establish the usefulness of fluoroscopy-guided intra-articular injection. A fluoroscopy unit was used for 368 intra-articular injections of hyaluronic acid to 93 knees in 65 patients. Initially, blind needle positioning was conducted on the fluoroscopy table. The failure rate of the blind approach among the 368 injections was evaluated, and a relationship between the Kellgren-Lawrence grade (K-L grade) and the incidence of repeated failures using the blind approach was determined for injections to 52 knees in 37 patients who received a complete cycle of injections (five consecutive injections with a one-week interval between injections). Using a blind approach, 298 of 368 trials (81.2%) resulted in a needle tip being placed in an intra-articular location, while 70 of 368 trials resulted in an extra-articular placement of the needle tip. Among 52 knees to which a complete cycle of injection (five consecutive injections with a one-week interval between injections) was administered, repeated failure of intra-articular placement using the blind approach was seen for 18 knees (34.6%); a more severe K-L grade assigned was associated with a higher rate of repeated failure. However, the trend was not statistically significant based on the Chi-squared test ({rho} value = 0.14). Fluoroscopy-guided needle placement may be helpful to ensure therapeutic intra-articular injection of the knee.
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Usefulness of fluoroscopy-guided intra-articular injection of the knee
International Nuclear Information System (INIS)
Myung, Jae Sung; Lee, Joon Woo; Lee, Ji Yeon
2007-01-01
To determine the accuracy of the intra-articular location of hyaluronic acid injection using a blind approach and to establish the usefulness of fluoroscopy-guided intra-articular injection. A fluoroscopy unit was used for 368 intra-articular injections of hyaluronic acid to 93 knees in 65 patients. Initially, blind needle positioning was conducted on the fluoroscopy table. The failure rate of the blind approach among the 368 injections was evaluated, and a relationship between the Kellgren-Lawrence grade (K-L grade) and the incidence of repeated failures using the blind approach was determined for injections to 52 knees in 37 patients who received a complete cycle of injections (five consecutive injections with a one-week interval between injections). Using a blind approach, 298 of 368 trials (81.2%) resulted in a needle tip being placed in an intra-articular location, while 70 of 368 trials resulted in an extra-articular placement of the needle tip. Among 52 knees to which a complete cycle of injection (five consecutive injections with a one-week interval between injections) was administered, repeated failure of intra-articular placement using the blind approach was seen for 18 knees (34.6%); a more severe K-L grade assigned was associated with a higher rate of repeated failure. However, the trend was not statistically significant based on the Chi-squared test (ρ value = 0.14). Fluoroscopy-guided needle placement may be helpful to ensure therapeutic intra-articular injection of the knee
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Investigation of environmental pollution with pine needles by NAA
Energy Technology Data Exchange (ETDEWEB)
Lee, Kil Yong; Yoon, Yoon Yeol; Yang, Myung Kwon; Shim, Sang Kwon; Seo, Bum Kyoung [Korea Inst. of Geosience and Mineral Resources, Environmental Geology Division, Daejeon (Korea); Chung, Yong Sam [Korea Atomic Energy Research Inst., HANARO Center, Daejeon (Japan)
2002-04-01
NAA was studied to precision analysis of metallic elements in pine needle. The pine needle was investigated whether it can be feasible or not as a bio-monitor. Only one year old needle was taken from three different regions of urban, suburban and rural area in four seasons. The needle sample was divided with two aliquots, and then one was cleaned and the other was not. Loss and contamination of analytes were cautiously minimized when the needle was sample and transferred from mountain to laboratory and prepared for NAA. Some elements such as As, Br, Ce, W, Zn have shown different characteristics with regions and seasons as well as surface cleaning. It is found that about twenty elements in pine needle could be simply analyzed by NAA and the pine needle could be suitable as a bio-monitor for the monitoring of environmental pollution in Korea. (author)
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International Nuclear Information System (INIS)
Franquet, T.; Jiminez, F.J.; Eguizabal, C.; Bescos, J.M.
1991-01-01
We present a case of pericardial cyst with atypical location. CT has been very usefull for densitometric evaluation of mediastinal masses. Using a combination of cross-section diagnostic methods and fine-needle aspiration (FNA), we can carry out accurate diagnoses of cystic lesions located in uncommom sites. (Author)
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Nanofiber electrode and method of forming same
Energy Technology Data Exchange (ETDEWEB)
Pintauro, Peter N.; Zhang, Wenjing
2018-02-27
In one aspect, a method of forming an electrode for an electrochemical device is disclosed. In one embodiment, the method includes the steps of mixing at least a first amount of a catalyst and a second amount of an ionomer or uncharged polymer to form a solution and delivering the solution into a metallic needle having a needle tip. The method further includes the steps of applying a voltage between the needle tip and a collector substrate positioned at a distance from the needle tip, and extruding the solution from the needle tip at a flow rate such as to generate electrospun fibers and deposit the generated fibers on the collector substrate to form a mat with a porous network of fibers. Each fiber in the porous network of the mat has distributed particles of the catalyst. The method also includes the step of pressing the mat onto a membrane.
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Metastatic Chordoma: A Diagnostic Challenge on Fine Needle Aspiration
Directory of Open Access Journals (Sweden)
Ghassan Tranesh
2016-01-01
Full Text Available Chordomas are primary low grade malignant tumors of bone that usually arise within both ends of axial skeleton. The Notochord is a midline, ectoderm-derived structure that defines the phylum of chordates. Chordomas may pose difficult diagnostic challenges when encountered in secondary locations, such as lungs or other parenchymatous organs. We report the cytologic findings of a metastatic chordoma sampled through CT-scan guided fine needle aspiration (FNA of lower lobe lung nodule in a 54-year-old man diagnosed with recurrent chordoma involving the lumber spine and paraspinal region.
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Directory of Open Access Journals (Sweden)
Renata Nobre MOURA
2014-12-01
Full Text Available Context Tissue sampling of renal masses is traditionally performed via the percutaneous approach or laparoscopicaly. The utility of endoscopic ultrasound to biopsy renal lesions it remains unclear and few cases have been reported. Objectives To evaluate the feasibility and outcome of endoscopic ultrasound fine needle aspiration of renal tumors. Methods Consecutive subjects undergoing attempted endoscopic ultrasound fine needle aspiration of a kidney mass after evaluation with computerized tomography or magnetic resonance. Results Ten procedures were performed in nine male patients (median age 54.7 years on the right (n = 4 and left kidney (n = 4 and bilaterally (n = 1. Kidney masses (median diameter 55 mm ; range 13-160 mm were located in the upper pole (n = 3, the lower pole (n = 2 and the mesorenal region (n = 3. In two cases, the mass involved more than one kidney region. Surgical resection confirmed renal cell carcinoma in six patients in whom pre-operative endoscopic ultrasound fine needle aspiration demonstrated renal cell carcinoma. No complications were reported. Conclusions Endoscopic ultrasound fine needle aspiration appears as a safe and feasible procedure with good results and minimal morbidity.
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Simulation of CNT-AFM tip based on finite element analysis for targeted probe of the biological cell
Energy Technology Data Exchange (ETDEWEB)
Yousefi, Amin Termeh, E-mail: at.tyousefi@gmail.com; Miyake, Mikio, E-mail: miyakejaist@gmail.com; Ikeda, Shoichiro, E-mail: sho16.ikeda@gmail.com [ChECA IKohza, Dept. Environmental & Green Technology (EGT), Malaysia, Japan International Institute of Technology (MJIIT), University Technology Malaysia - UTM, Kualalumpur (Malaysia); Mahmood, Mohamad Rusop, E-mail: nano@uitm.gmail.com [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)
2016-07-06
Carbon nanotubes (CNTs) are potentially ideal tips for atomic force microscopy (AFM) due to the robust mechanical properties, nano scale diameter and also their ability to be functionalized by chemical and biological components at the tip ends. This contribution develops the idea of using CNTs as an AFM tip in computational analysis of the biological cell’s. Finite element analysis employed for each section and displacement of the nodes located in the contact area was monitored by using an output database (ODB). This reliable integration of CNT-AFM tip process provides a new class of high performance nanoprobes for single biological cell analysis.
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Exploring needle anxiety among students attending a Nigerian ...
African Journals Online (AJOL)
Needle anxiety, a form of specific phobia refers to an intense fear of needles used for various medical procedures. It may result in the avoidance of such needle-involving procedures like intramuscular injections or vaccinations. About 4-8% of children and adolescents are said to generally suffer some form of anxiety.
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Observations on rotating needle insertions using a brachytherapy robot
International Nuclear Information System (INIS)
Meltsner, M A; Ferrier, N J; Thomadsen, B R
2007-01-01
A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy
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Estimation of plasma ion saturation current and reduced tip arcing using Langmuir probe harmonics.
Boedo, J A; Rudakov, D L
2017-03-01
We present a method to calculate the ion saturation current, I sat , for Langmuir probes at high frequency (>100 kHz) using the harmonics technique and we compare that to a direct measurement of I sat . It is noted that the I sat estimation can be made directly by the ratio of harmonic amplitudes, without explicitly calculating T e . We also demonstrate that since the probe tips using the harmonic method are oscillating near the floating potential, drawing little power, this method reduces tip heating and arcing and allows plasma density measurements at a plasma power flux that would cause continuously biased tips to arc. A multi-probe array is used, with two spatially separated tips employing the harmonics technique and measuring the amplitude of at least two harmonics per tip. A third tip, located between the other two, measures the ion saturation current directly. We compare the measured and calculated ion saturation currents for a variety of plasma conditions and demonstrate the validity of the technique and its use in reducing arcs.
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Insertion mechanics of bioinspired needles into soft tissues.
Sahlabadi, Mohammad; Khodaei, Seyedvahid; Jezler, Kyle; Hutapea, Parsaoran
2017-12-22
Most studies to date confirm that any increase in the needle insertion force increases the damage to the tissue. When it comes to brain tissue, even minor damage can cause a long-lasting traumatic brain injury. Thus there is a great demand for innovative minimally invasive needles among the medical community. In our previous studies a novel bioinspired needle design with specially designed barbs was used to perform insertion tests into Polyvinyl chloride (PVC) tissue-mimicking gels, in which it decreased the insertion force by as much as 25%. In this work, bioinspired needles were designed using a CAD software, and were then manufactured using a 3 D printer. The insertion tests into bovine brain and liver were then performed to further investigate the performance of our bioinspired needles in real tissues. Our results show that there was a 10-25% decrease in the insertion force for insertions into bovine brain, and a 35-45% reduction in the insertion force for insertions into bovine liver using the proposed bioinspired needles. The reduction in the insertion force is due to the decrease in the friction force of the bioinspired needle with the bovine tissues, and its results are consistent with our previous results.
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High-pressure needle interface for thermoplastic microfluidics.
Chen, C F; Liu, J; Hromada, L P; Tsao, C W; Chang, C C; DeVoe, D L
2009-01-07
A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.
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Mathematics Teacher, 2004
2004-01-01
Some inexpensive or free ways that enable to capture and use images in work are mentioned. The first tip demonstrates the methods of using some of the built-in capabilities of the Macintosh and Windows-based PC operating systems, and the second tip describes methods to capture and create images using SnagIt.
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Computed tomography guided needle biopsy: experience from 1,300 procedures
Energy Technology Data Exchange (ETDEWEB)
Chojniak, Rubens; Isberner, Rony Klaus; Viana, Luciana Marinho; Yu, Liao Shin; Aita, Alessandro Amorim; Soares, Fernando Augusto [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Radiologia e Patologia
2006-01-15
Context and objective: computed tomography (CT) guided biopsy is widely accepted as effective and safe for diagnosis in many settings. Accuracy depends on target organ and needle type. Cutting needles present advantages over fine needles. This study presents experience from CT guided biopsies performed at an oncology center. Design and setting: retrospective study at Hospital do Cancer A. C. Camargo, Sao Paulo.Methods: 1,300 consecutive CT guided biopsies performed between July 1994 and February 2000 were analyzed. Nodules or masses were suspected as primary malignancy in 845 cases (65%) or metastatic lesion in 455 (35%). 628 lesions were thoracic, 281 abdominal, 208 retroperitoneal, 134 musculoskeletal and 49 head/neck. All biopsies were performed by one radiologist or under his supervision: 765 (59%) with 22-gauge fine-needle/aspiration technique and 535 (41%) with automated 16 or 18-gauge cutting-needle biopsy. Results: adequate samples were obtained in 70-92% of fine-needle and 93-100% of cutting-needle biopsies. The specific diagnosis rates were 54-67% for fine-needle and 82-100% for cutting-needle biopsies, according to biopsy site. For any site, sample adequacy and specific diagnosis rate were always better for cutting-needle biopsy. Among 530 lung biopsies, there were 84 pneumothorax (16%) and two hemothorax (0.3%) cases, with thoracic drainage in 24 (4.9%). Among abdominal and retroperitoneal biopsies, there were two cases of major bleeding and one of peritonitis. Conclusion: both types of needle showed satisfactory results, but cutting-needle biopsy should be used when specific diagnosis is desired without greater incidence of complications. (author)
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Directory of Open Access Journals (Sweden)
Joshi RS
2017-06-01
-degree tip can yield effective hard nucleus phacoemulsification, no statistically significant difference was found in EPT, CDE and NET between the two groups. Keywords: phacoemulsification, bevel up and bevel down phaco needle, effective phaco time, cumulative dissipated energy
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Cervical Transforaminal Epidural Steroid Injection (Taffies): Role of MR Imaging and Epidurography
International Nuclear Information System (INIS)
Choi, Soo Jung; Ahn, Jae Hong; Kim, Chung Hwan; Jung, Seung Moon; Ryu, Dae Sik; Park, Man Soo; Lee, Jong Hyeog; Song, Jae Seok
2011-01-01
To evaluate the relationship between MR/epidurographic findings and the clinical outcome after a fluoroscopy-guided transforaminal epidural steroid injection (TFESI) in patients with cervical radicular pain. Forty-five patients who had taken a cervical TFESI in our department were included in this study. We retrospectively reviewed MR and epidurographic findings to see if there was a relationship between these methods and the amount of pain relief, by way of a multiple regression analysis. On MR imaging, there was significant relationship between the amount of pain relief and location of herniated intervertebral disc (HIVD, central: 54.4%, lateral recess: 69.4%, foraminal: 59%: p = 0.048). There was no significant difference regarding the other MR findings. On epidurographic findings, there was significant difference in the amount of pain relief with the extent of the contrast (epidural and epineural space, 65.3%: epineural space only, 64.2%: p = 0.03) and location of the needle tip (in the foramen, 59.4%: outside the foramen, 68.4%: p = 0.002). The results indicate that TFESI could be more useful in patients with cervical HIVD in lateral recess rather than another location. Contrast spread into epidural reflux appears to be a favorable injection pattern. Needle tip location is recommended outside the foramen rather than in the foramen
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International Nuclear Information System (INIS)
Thanos, Loukas; Galani, Panagiota; Mylona, Sophia; Pomoni, Maria; Mpatakis, Nikolaos
2004-01-01
The purpose of this study was to determine the diagnostic value of percutaneous core needle biopsy (CNB) relative to fine needle aspiration (FNA) in patients with pneumonia and pneumonia mimics. In this prospective study we present our experience with 48 thoracic FNAs and CNBs carried out on 48 patients with pneumonia and pneumonia mimics. Samples were obtained from all patients using both CNB (with an automated 18-G core biopsy needle and a gun) and FNA (with a 22-G needle). A specific diagnosis was made in 10/48 cases (20.83%) by FNA and in 42/48 (87.5%) by CNB. The main complications encountered were pneumothorax (n = 4) and hemoptysis (n = 2), yielding a total complication rate of 12.5%. We concluded that CNB using an automated biopsy gun results in a higher diagnostic accuracy for pneumonia and pneumonia mimic biopsies than FNA. Complications should be considered and proper patient observation should follow the procedure
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High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions
SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.
2011-01-01
This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retrac...
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Composition and Chemical Variability of the Needle Oil from Pinus halepensis growing in Corsica.
Nam, Anne-Marie; Tomi, Félix; Gibernau, Marc; Casanova, Joseph; Bighelli, Ange
2016-04-01
The composition of oil samples isolated from needles of Pinus halepensis growing in three locations in Corsica (Saleccia, Capo di Feno, and Tre Padule) has been investigated by combination of chromatographic (GC with retention indices) and spectroscopic (MS and (13)C-NMR) techniques. In total, 35 compounds that accounted for 77 - 100% of the whole composition have been identified. α-Pinene, myrcene, and (E)-β-caryophyllene were the major component followed by α-humulene and 2-phenylethyl isovalerate. Various diterpenes have been identified as minor components. 47 Oil samples isolated from pine needles have been analyzed and were differentiated in two groups. Oil samples of the first group (15 samples) contained myrcene (M = 28.1 g/100 g; SD = 10.6) and (E)-β-caryophyllene (M = 19.0 g/100 g; SD = 2.2) as major components and diterpenes were absent. All these oil samples were isolated from pine needles harvested in Saleccia. Oil samples of the second group (32 samples) contained mostly (E)-β-caryophyllene (M = 28.7 g/100 g; SD = 7.9), α-pinene (M = 12.3 g/100 g; SD = 3.6), and myrcene (M = 11.7 g/100 g; SD = 7.3). All these oil samples were isolated from pine needles harvested in Capo di Feno and Tre Padule. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.
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Chen, Dan; Xie, Qiange; Huang, Bing-Lin
2014-01-01
Professor XIE Qiang's Tihu Guanding needling method, a kind of acupuncture method which takes acupoints of the Conception Vessel as the primary and acupoints of the Governor Vessel as the secondary. Acupoints Lianquan (CV 23), Tiantu (CV 22), Qihai (CV 6), Zhongwan (CV 12), Baihui (GV 20) and Dazhui (GV 14) are adopted as the basic ones. Other points can be added according to various symptoms, for instance, Yingxiang (LI 20) and Yintang (GV 29) for rhinopathy, Tinggong (SI 19) and Yifeng (TE 17) for otopathy, Yan'an (Professor XIE's experience) and Shanglianquan (EX-HN 21) for pharyngopathy and Kaiyin 1 (Professor XIE's experience) and Kaiyin 2 (Professor XIE's experience) for laryngopathy. During the needle retention, rotation manipulation should be done every 5 min at Lianquan (CV 23). And the patient should be told to put the tip of one's tongue at the the palate as well as to do deep breathing to communicate the Conception Vessel and the Governor Vessel. Moxibustion is adopted at Yongquan (KI 1) to induce the up floating fire to mingmen (where the primary yang is stored). The therapeutic effect on treatment of persistent otorhinolaryngologic diseases with the above mentioned method is approve to be good.
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Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules.
Raikov, Nikolai; Nonchev, Boyan; Chaushev, Borislav; Vjagova, Diyana; Todorov, Svetoslav; Bocheva, Yana; Malceva, Daniela; Vicheva, Snejinka; Raikova, Asyia; Argatska, Antoaneta; Raikov, Miroslav
2016-01-01
The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy.
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Directory of Open Access Journals (Sweden)
Jaung-Geng Lin
2013-01-01
Full Text Available Objective. To explore the existing scientific information regarding safe needling depth of acupuncture points and the needling depth of clinical efficacy. Methods. We searched the PubMed, EMBASE, Cochrane, Allied and Complementary Medicine (AMED, The National Center for Complementary and Alternative Medicine (NCCAM, and China National Knowledge Infrastructure (CNKI databases to identify relevant monographs and related references from 1991 to 2013. Chinese journals and theses/dissertations were hand searched. Results. 47 studies were recruited and divided into 6 groups by measuring tools, that is, MRI, in vivo evaluation, CT, ultrasound, dissected specimen of cadavers, and another group with clinical efficacy. Each research was analyzed for study design, definition of safe depth, and factors that would affect the measured depths. Depths of clinical efficacy were discussed from the perspective of de-qi and other clinical observations. Conclusions. Great inconsistency in depth of each point measured from different subject groups and tools exists. The definition of safe depth should be established through standardization. There is also lack of researches to compare the clinical efficacy. A well-designed clinical trial selecting proper measuring tools to decide the actual and advisable needling depth for each point, to avoid adverse effects or complications and promote optimal clinical efficacy, is a top priority.
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Ultrasound guided percutaneous fine needle aspiration biopsy ...
African Journals Online (AJOL)
)-guided percutaneous fine needle aspiration biopsy (PFNAB)/US-guided percutaneous needle core biopsy (PNCB) of abdominal lesions is efficacious in diagnosis, is helpful in treatment choice, to evaluate whether various other investigations ...
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A retrospective analysis of ultrasound-guided large core needle ...
African Journals Online (AJOL)
2016-07-27
Jul 27, 2016 ... The different types of non-surgical breast biopsy procedures include: fine needle aspiration biopsy. (FNAB), core needle ... needle biopsies of breast lesions at a regional public hospital in ..... NCR_2009_FINAL.pdf. 2. Parikh J ...
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Mutual inductance instability of the tip vortices behind a wind turbine
DEFF Research Database (Denmark)
Sarmast, Sasan; Dadfar, Reza; Mikkelsen, Robert Flemming
2014-01-01
Two modal decomposition techniques are employed to analyse the stability of wind turbine wakes. A numerical study on a single wind turbine wake is carried out focusing on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large......-eddy simulations (LES) of the Navier–Stokes equations using the actuator line (ACL) method to simulate the wake behind the Tjæreborg wind turbine. The wake is perturbed by low-amplitude excitation sources located in the neighbourhood of the tip spirals. The amplification of the waves travelling along the spiral...
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Laser-Controlled Growth of Needle-Shaped Organic Nanoaggregates
DEFF Research Database (Denmark)
Balzer, Frank; Rubahn, Horst-Günter
2002-01-01
Arrays of mutually parallel oriented, single-crystalline, needle-like structures of light-emitting p-hexaphenyl molecules are generated in the focus of an argon ion laser. The cross sectional dimensions of the needles are of the order of 100 to 200 nm with lengths up to several hundred micrometer....... While the orientation of the individual molecules in the needles is defined by the direction of surface dipoles, the localization on the surface, the length distribution as well as mutual distances can be adjusted via size and position of the laser focus spot.......Arrays of mutually parallel oriented, single-crystalline, needle-like structures of light-emitting p-hexaphenyl molecules are generated in the focus of an argon ion laser. The cross sectional dimensions of the needles are of the order of 100 to 200 nm with lengths up to several hundred micrometers...
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International Nuclear Information System (INIS)
Altaf, H.N.; Farooqui, F.
2015-01-01
Objective: To compare ultrasound guided fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) in patients presenting with palpable breast lumps (PBLs), in terms of sensitivity and specificity, taking final histopathology as gold standard. Methodology: This cross-sectional study was conducted at Holy Family Hospital, Rawalpindi, Pakistan. Ultrasound guided FNAC and CNB were taken of all female patients with PBLs. The results were compared with final histopathology as gold standard. Data analysis was performed using SPSS software and chi-square test. Results: A total of 60 patients were included in the study. The mean age was 33.8 yrs. The sensitivity and specificity of ultrasound guided FNAC were 68.7% and 93.1%, respectively. The sensitivity and specificity of ultrasound guided CNB was 93.7% and 100%. The accuracy of FNAC was 86.2% and that of core needle biopsy was 98.3%. Conclusion: The ultrasound guided core needle biopsy can be used as an initial diagnostic test for the evaluation of all PBLs. Because of high negative predictive value core needle biopsy can replace surgical excision biopsy for benign lesions. (author)
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Role of needle surface waxes in dynamic exchange of mono- and sesquiterpenes
Directory of Open Access Journals (Sweden)
J. Joensuu
2016-06-01
Full Text Available Biogenic volatile organic compounds (BVOCs produced by plants have a major role in atmospheric chemistry. The different physicochemical properties of BVOCs affect their transport within and out of the plant as well as their reactions along the way. Some of these compounds may accumulate in or on the waxy surface layer of conifer needles and participate in chemical reactions on or near the foliage surface. The aim of this work was to determine whether terpenes, a key category of BVOCs produced by trees, can be found on the epicuticles of Scots pine (Pinus sylvestris L. and, if so, how they compare with the terpenes found in shoot emissions of the same tree. We measured shoot-level emissions of pine seedlings at a remote outdoor location in central Finland and subsequently analysed the needle surface waxes for the same compounds. Both emissions and wax extracts were clearly dominated by monoterpenes, but the proportion of sesquiterpenes was higher in the wax extracts. There were also differences in the terpene spectra of the emissions and the wax extracts. The results, therefore, support the existence of BVOC associated to the epicuticular waxes. We briefly discuss the different pathways for terpenes to reach the needle surfaces and the implications for air chemistry.
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Quantification of Tissue Trauma following Insulin Pen Needle Insertions in Skin
DEFF Research Database (Denmark)
Jensen, Casper Bo; Larsen, Rasmus; Vestergaard, Jacob Schack
Objective: Within the field of pen needle development, most research on needle design revolves around mechanical tensile testing and patient statements. Only little has been published on the actual biological skin response to needle insertions. The objective of this study was to develop a computa......Objective: Within the field of pen needle development, most research on needle design revolves around mechanical tensile testing and patient statements. Only little has been published on the actual biological skin response to needle insertions. The objective of this study was to develop...... a computational method to quantify tissue trauma based on skin bleeding and immune response. Method: Two common sized pen needles of 28G (0.36mm) and 32G (0.23mm) were inserted into skin of sedated LYD pigs prior to termination. Four pigs were included and a total of 32 randomized needle insertions were conducted...... diameter. Conclusion: A computational and quantitative method has been developed to assess tissue trauma following insulin pen needle insertions. Application of the method is tested by conduction of a needle diameter study. The obtained quantitative measures of tissue trauma correlate positively to needle...
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DEFF Research Database (Denmark)
Andreasen, Martin Møller; Christensen, Jens H.E.; Simon Riddell, Simon
We introduce an arbitrage-free term structure model of nominal and real yields that accounts for liquidity risk in Treasury inflation-protected securities (TIPS). The novel feature of our model is to identify liquidity risk from individual TIPS prices by accounting for the tendency that TIPS, lik...
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International Nuclear Information System (INIS)
Mizeraczyk, J; Berendt, A; Podlinski, J
2016-01-01
In this paper we present images showing the temporal and spatial evolution of the electrohydrodynamic (EHD) flow of dust particles (cigarette smoke) suspended in still air in a needle-to-plate negative DC corona discharge arrangement just after the corona onset, i.e. in the first stage of development of the EHD particle flow. The experimental apparatus for our study of the EHD flow onset consisted of a needle-to-plate electrode arrangement, high voltage power supply and time-resolved EHD imaging system based on 2D time-resolved particle image velocimetry equipment. The time-resolved flow images clearly show the formation of a ball-like flow structure at the needle tip just after the corona discharge onset, and its evolution into a mushroom-like object moving to the collecting electrode. After a certain time, when the mushroom-like object is still present in the interelectrode gap a second mushroom-like object forms near the needle electrode and starts to move towards the collecting electrode. Before the first mushroom-like object reaches the collecting electrode several similar mushroom-like objects can be formed and presented simultaneously in the interelectrode gap. They look like a series of mushroom-like minijets shot from the needle electrode vicinity towards the collecting electrode. The simultaneous presence of mushroom-like minijets in the interelectrode gap in the corona discharge in particle-seeded air resembles the negative-ion-charged ‘clouds’ (induced by the Trichel pulses) traversing simultaneously the interelectrode gap of the corona discharge in air, predicted a long time ago by Loeb, and Lama and Gallo and recently by Dordizadeh et al . Analysing the time behaviours of the mushroom-like minijets and current waveform in the corona discharge in particle-seeded air, we found that the Trichel pulse trains, formed just after the corona onset initiates the mushroom-like minijets. The first stage of development of the EHD particle flow, the area of
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High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions
SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.
2014-01-01
This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retraction to enable the brachytherapy procedure with the preloaded needles. The device mimics the manual physician gesture by two point grasping (hub and base) and provides direct force measurement of needle insertion force by fiber optic force sensors. The fabricated prototype is presented and an experiment with phantom trials in 3T MRI is analyzed to demonstrate the system compatibility. PMID:21335868
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Sharpening of hollow silicon microneedles to reduce skin penetration force
International Nuclear Information System (INIS)
Khanna, Puneet; Luongo, Kevin; Bhansali, Shekhar; Strom, Joel A
2010-01-01
In this research, hollow silicon microneedles with sharpened tips have been fabricated without any reduction to the needle shaft diameter. By sharpening the needles only at the tip and not over the entire length of the needle, their mechanical strength is maintained, while reducing the insertion force into skin. The process achieves this geometry by novel use photoresist depletion during DRIE. Microneedles of varying levels of tip sharpness were tested on human cadaver skin to measure their force of penetration. The results show a marked decrease of insertion force with progressive sharpening of microneedle tips, reducing more than 75 times in magnitude for extremely sharp tips. The toughness of human skin was derived to be approximately 24.28 kJ m −2 .
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Structure and photoluminescence properties of Ag-coated ZnO nano-needles
Energy Technology Data Exchange (ETDEWEB)
Li Xiaozhu, E-mail: Lixiaozhu1019@21cn.com [Department of Physics, Shaoguan University, Shaoguan, Guangdong 512005 (China) and Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan, Hubei 430072 (China); Wang Yongqian [Engineering Research Center of Nano-Geomaterials of Ministry of Education (China University of Geosciences), Wuhan, Hubei 430074 (China)
2011-05-12
Highlights: > ZnO nano-needles were synthesized by thermal oxidation. > Their surfaces were coated with Ag by pulse electro-deposition technique. > The uncoated and coated ZnO nano-needles were characterized. > The results showed that the prepared ZnO nano-needles have been coated with Ag successfully. > The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the Ag-coated ZnO nano-needles can increase the absorption of UV light. - Abstract: A large number of zinc oxide (ZnO) nano-needles were synthesized by thermal oxidation of pure zinc. The surfaces of ZnO nano-needles were coated with a layer of Ag by pulse electro-deposition technique. The uncoated and coated ZnO nano-needles were characterized by using the X-ray diffraction and the scanning electron microscope (SEM). The results showed that the uncoated samples were close-packed hexagonal structure, which showed needle-like morphology. Their average diameter is about 40 nm, lengths up to 5 {mu}m. At the same time we observed that the prepared ZnO nano-needles have been coated with Ag successfully. The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the uncoated ZnO nano-needles have two fluorescence peaks at 388 nm and 470.8 nm, respectively, the relative intensity of 143.4 and 93.61; and the Ag-coated ZnO nano-needles showed a pair of strong peaks at 387.4 nm and 405.2 nm, the relative intensity of 1366 and 1305, respectively, indicating that the Ag-coated ZnO nano-needles can increase the absorption of UV light.
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Evaluation of Aircraft Wing-Tip Vortex Using PIV
Alsayed, Omer A.; Asrar, Waqar; Omar, Ashraf A.
2010-06-01
The formation and development of a wing-tip vortex in a near and extended near filed were studied experimentally. Particle image velocimetry was used in a wind tunnel to measure the tip vortex velocity field and hence investigate the flow structure in a wake of aircraft half-wing model. The purpose of this investigation is to evaluate the main features of the lift generated vortices in order to find ways to alleviate hazardous wake vortex encounters for follower airplanes during start and approach such that the increase in airport capacity can be achieved. First the wake structure at successive downstream planes crosswise to the axis of the wake vortices was investigated by measuring parameters such as core radius, maximum tangential velocities, vorticities and circulation distributions. The effect of different angles of attack setting on vortex parameters was examined at one downstream location. In very early stages the vortex sheet evolution makes the tip vortex to move inward and to the suction side of the wing. While the core radius and circulation distributions hardly vary with the downstream distance, noticeable differences for the same vortex parameters at different angles of attack settings were observed. The center of the wing tip vortices scatter in a circle of radius nearly equal to 1% of the mean wing chord and wandering amplitudes shows no direct dependence on the vortex strength but linearly increase with the downstream distance.
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Master-slave robotic system for needle indentation and insertion.
Shin, Jaehyun; Zhong, Yongmin; Gu, Chengfan
2017-12-01
Bilateral control of a master-slave robotic system is a challenging issue in robotic-assisted minimally invasive surgery. It requires the knowledge on contact interaction between a surgical (slave) robot and soft tissues. This paper presents a master-slave robotic system for needle indentation and insertion. This master-slave robotic system is able to characterize the contact interaction between the robotic needle and soft tissues. A bilateral controller is implemented using a linear motor for robotic needle indentation and insertion. A new nonlinear state observer is developed to online monitor the contact interaction with soft tissues. Experimental results demonstrate the efficacy of the proposed master-slave robotic system for robotic needle indentation and needle insertion.
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Sweeney, K. E.; Roering, J. J.; Rempel, A. W.
2012-12-01
Convex hilltops formed by diffusive sediment transport are a fundamental feature of soil-mantled landscapes worldwide. Additionally, the competition and interaction between hillslopes and valleys control basic topographic metrics, such as relief, drainage density, and breaks in slope-area scaling. Despite recent progress in erosive landscape experiments, no published work has explored the competition of hillslope diffusion and channel advection experimentally. Here, we present preliminary findings on the plausibility of needle ice driven frost creep as a mechanism for laboratory hillslope transport of wet sediment. In nature, needle ice is a diurnal form of ice segregation, whereby liquid water held in sediment pore space is driven upward toward a near-surface freezing front by a temperature-controlled liquid pressure gradient. As needles grow perpendicular to the surface, sediment is incorporated in the growing needle ice by temperature perturbations and associated downward shifts in the freezing front. Sediment then moves downslope due to melting or sublimation of the ice needles. We constructed a slope of saturated sediment in a freezer to constrain the temperature, grain size, and soil moisture limits on laboratory needle ice growth and sediment transport. Surficial sediment transport is measured during experimentation by tracking the movement of colored grains. Additionally, at the end of each run we measure depth-dependent sediment transport by taking slices of the experimental slope and observing the displacement of buried columns of colored grains. In agreement with past work, we find that with temperatures just below freezing, soil moisture above 35%, and silt-sized sediment, the moisture migration induced by freezing releases enough latent heat to maintain the location of the freezing front and encourage needle ice growth. Our experiments demonstrate that the amount of sediment incorporated during needle growth, i.e., the transport efficiency, can be
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Robotic needle steering: design, modeling, planning, and image guidance
Cowan, Noah J.; Goldberg, Ken; Chirikjian, Gregory S.; Fichtinger, Gabor; Alterovitz, Ron; Reed, Kyle B.; Kallem, Vinutha; Misra, Sarthak; Park, Wooram; Okamura, Allison M.; Rosen, Jacob; Hannaford, Blake; Satava, Richard M.
2010-01-01
This chapter describes how advances in needle design, modeling, planning, and image guidance make it possible to steer flexible needles from outside the body to reach specified anatomical targets not accessible using traditional needle insertion methods. Steering can be achieved using a variety of
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Tang, Zhouwen; Igbinomwanhia, Efehi; Elhanafi, Sherif; Othman, Mohamed O
2016-01-01
Background and Aim. A successful endoscopic ultrasound guided rendezvous (EUS-RV) biliary drainage is dependent on accurate puncture of the bile duct and precise guide wire manipulation across the ampulla of Vater. We aim to study the feasibility of using a flexible 19-gauge fine aspiration needle in the performance of EUS-RV biliary drainage. Method. This is a retrospective case series of EUS-RV biliary drainage procedures at a single center. Patients who failed ERCP during the same session for benign or malignant biliary obstruction underwent EUS-RV using a flexible, nitinol covered, 19-gauge needle for biliary access and guide wire manipulation. Result. 24 patients underwent EUS-RV biliary drainage via extrahepatic access while 1 attempt was via intrahepatic access. The technical success rate was 80%, including 83.3% of cases via extrahepatic access. There was no significant difference in success rate of inpatient and outpatient procedures, benign or malignant indications, or type of guide wire used. Adverse events included mild pancreatitis (3 patients) and cholangitis (1 patient). Conclusion. A flexible 19-gauge needle for biliary access can be safe and effective when used to perform EUS-RV biliary drainage. Direct comparison between the nitinol needle and conventional metal needles in the performance of EUS guided biliary drainage is needed.
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NUTRIENTS CONCENTRATION AND RETRANSLOCATION IN THE Pinus taeda L. NEEDLES
Directory of Open Access Journals (Sweden)
Márcio Viera
2010-03-01
Full Text Available Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West, sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients. The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.
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Novel Double-Needle System That Can Prevent Intravascular Injection of Any Filler
Directory of Open Access Journals (Sweden)
Hsiang Huang, MD
2017-09-01
Full Text Available Summary:. A new type of needle system combines 2 parts, an inner needle and an outer needle. The inner needle is used for filler injection and the outer needle acts as a guiding needle that can observe blood reflow when inserting into the vessel lumen during injection process. This new needle system can be used for all kinds of filler, providing real time monitoring for physician and preventing intravascular injection of any filler.
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AERODYNAMICS OF WING TIP SAILS
Directory of Open Access Journals (Sweden)
MUSHTAK AL-ATABI
2006-06-01
Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.
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Structure and photoluminescence properties of Ag-coated ZnO nano-needles
International Nuclear Information System (INIS)
Li Xiaozhu; Wang Yongqian
2011-01-01
Highlights: → ZnO nano-needles were synthesized by thermal oxidation. → Their surfaces were coated with Ag by pulse electro-deposition technique. → The uncoated and coated ZnO nano-needles were characterized. → The results showed that the prepared ZnO nano-needles have been coated with Ag successfully. → The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the Ag-coated ZnO nano-needles can increase the absorption of UV light. - Abstract: A large number of zinc oxide (ZnO) nano-needles were synthesized by thermal oxidation of pure zinc. The surfaces of ZnO nano-needles were coated with a layer of Ag by pulse electro-deposition technique. The uncoated and coated ZnO nano-needles were characterized by using the X-ray diffraction and the scanning electron microscope (SEM). The results showed that the uncoated samples were close-packed hexagonal structure, which showed needle-like morphology. Their average diameter is about 40 nm, lengths up to 5 μm. At the same time we observed that the prepared ZnO nano-needles have been coated with Ag successfully. The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the uncoated ZnO nano-needles have two fluorescence peaks at 388 nm and 470.8 nm, respectively, the relative intensity of 143.4 and 93.61; and the Ag-coated ZnO nano-needles showed a pair of strong peaks at 387.4 nm and 405.2 nm, the relative intensity of 1366 and 1305, respectively, indicating that the Ag-coated ZnO nano-needles can increase the absorption of UV light.
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Robust path planning for flexible needle insertion using Markov decision processes.
Tan, Xiaoyu; Yu, Pengqian; Lim, Kah-Bin; Chui, Chee-Kong
2018-05-11
Flexible needle has the potential to accurately navigate to a treatment region in the least invasive manner. We propose a new planning method using Markov decision processes (MDPs) for flexible needle navigation that can perform robust path planning and steering under the circumstance of complex tissue-needle interactions. This method enhances the robustness of flexible needle steering from three different perspectives. First, the method considers the problem caused by soft tissue deformation. The method then resolves the common needle penetration failure caused by patterns of targets, while the last solution addresses the uncertainty issues in flexible needle motion due to complex and unpredictable tissue-needle interaction. Computer simulation and phantom experimental results show that the proposed method can perform robust planning and generate a secure control policy for flexible needle steering. Compared with a traditional method using MDPs, the proposed method achieves higher accuracy and probability of success in avoiding obstacles under complicated and uncertain tissue-needle interactions. Future work will involve experiment with biological tissue in vivo. The proposed robust path planning method can securely steer flexible needle within soft phantom tissues and achieve high adaptability in computer simulation.
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Light production by the arm tips of the deep-sea cephalopod Vampyroteuthis infernalis.
Robison, Bruce H; Reisenbichler, Kim R; Hunt, James C; Haddock, Steven H D
2003-10-01
The archaic, deep-sea cephalopod Vampyroteuthis infernalis occurs in dark, oxygen-poor waters below 600 m off Monterey Bay, California. Living specimens, collected gently with a remotely operated vehicle (ROV) and quickly transported to a laboratory ashore, have revealed two hitherto undescribed means of bioluminescent expression for the species. In the first, light is produced by a new type of organ located at the tips of all eight arms. In the second, a viscous fluid containing microscopic luminous particles is released from the arm tips to form a glowing cloud around the animal. Both modes of light production are apparently linked to anti-predation strategies. Use of the tip-lights is readily educed by contact stimuli, while fluid expulsion has a much higher triggering threshold. Coelenterazine and luciferase are the chemical precursors of light production. This paper presents observations on the structure and operation of the arm-tip light organs, the character of the luminous cloud, and how the light they produce is incorporated into behavioral patterns.
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Parikh, Mihir S; Seeley, Eric; Nguyen-Tran, Evelyn; Krishna, Ganesh
2017-10-01
Surgical treatment with lung resection has traditionally been the treatment of choice for pulmonary cavities containing aspergillomas that cause hemoptysis. Endobronchial ultrasound (EBUS) is a minimally invasive bronchoscopic technique that is commonly used for transbronchial needle aspiration of hilar and mediastinal lymph nodes as well as centrally located parenchymal lesions. Here, we describe a case of a 71-year-old woman who was found to have a cavitary lesion in the lung containing aspergillomas. Under direct ultrasound visualization with EBUS, liposomal amphotericin B was injected into the aspergillomas. These aspergillomas regressed after treatment. To our knowledge, this is the first reported treatment of aspergilloma with EBUS-guided transbronchial needle injection of liposomal amphotericin B.
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[Doctor HUANG Shi-ping's acupuncture with golden needles].
Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang
2013-08-01
Taking Doctor HUANG Shi-ping as the representative, the school of Huang's golden needle is based on Chinese martial art. Golden needles are adopted as main tool. Attaching great importance on the combination of acupuncture and moxibustioin, it is also characterized with penetrating needling with long needles. Through the development of three generations, it once outshone other schools in the field of acupuncture, and became famous all over the world. It made great contribution to the development of the course of acupuncture. However, with the development of the history, the form of acupuncture education as well as apparatus were all undergone an unified reform. Therefore, Doctor HUANG Shi-ping's acupuncture school be lost gradually.
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Diagenesis of conifer needles in a coastal marine environment
Hedges, John I.; Weliky, K.
1989-10-01
Physically intact fir, hemlock and cedar needles were isolated from different horizons of a sediment core from a coastal marine bay (Dabob Bay, Washington State, U.S.A.) and from nearby trees and forest litter. Green fir, hemlock and cedar needles were all characterized by glucose-rich aldose mixtures (~30% of tissue carbon), the production of vanillyl and cinnamyl CuO-derived phenols (~8% of tissue carbon) and the presence of both pinitol and myo-inositol (1-2% of tissue carbon). Needles from forest litter were enriched in lignin phenols and non-glucose aldoses and depleted in glucose and cyclitols. The sediment core contained an average of 10 mg/1 of physically intact fir, hemlock and cedar needles, which occurred in similar relative abundances and accounted for less than 1% of the total nonwoody gymnosperm tissue. Compared to the green and litter counterparts, all sedimentary needles were greatly depleted in cyclitols, glucose and p-coumaric acid and enriched in vanillyl phenol precursors. The degree of elevation of vanillyl phenol yield from the degraded needles was used to estimate minimal carbon losses from the samples, which ranged from near 40% for needle litter to almost 70% for the deepest (~100 years old) sedimentary fir/hemlock samples. Although downcore increases in carbon loss and refractory organic components indicated in situ diagenesis, the bulk of overall degradation occurred either on land or during the first 10-20 years after deposition. Atomic C/N ratios of degraded needles were lower than for green counterparts, but nitrogen was lost overall. These relative changes indicate the following stability series: vanillyl phenols > N > ferulic acid, p-hydroxy phenols, most aldoses and bulk tissue > glucose and p-coumaric acid > cyclitols (near 100% loss). Vanillic acid to vanillin ratios, (Ad/Al)v, of the green fir and hemlock needles were unusually high (0.36-0.38) and decreased downcore. Diagenesis also decreased the cinnamyl/vanillyl phenol ratio
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Freehand biopsy guided by electromagnetic needle tracking
DEFF Research Database (Denmark)
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
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Rooting of needle fascicles from western white pine seedlings
Ramond J. Hoff; Geral I. McDonald
1968-01-01
In one test, 45 out of 318 (14 percent) needle fascicles from 2-year-old seedlings of Pinus monticola Dougl. were rooted. Eight of the needle fascicles produced shoot growth. In another test, 392 out of 742 (53 percent) needle fascicles were rooted, but none of these produced shoot growth.
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Islam, Mofizul; Wodak, Alex; Conigrave, Katherine M
2008-12-01
Syringe vending machines (SVMs) have been introduced in Europe and Australasia as part of the effort to increase the availability of sterile needles and syringes to injecting drug users (IDUs). This qualitative review of 14 published and grey literature studies examines whether community-based SVMs as a component of a comprehensive needle syringe programme (NSP) assist to reduce the spread of HIV and other blood-borne viruses amongst IDUs. The available evidence suggests that SVMs increase access to sterile injecting equipment, reduce needle and syringe sharing, and are likely to be cost efficient. SVMs also complement other modes of NSP delivery as they are used by IDUs who are less likely to attend staffed NSPs or pharmacies. If installed and properly maintained in a well-chosen location and with the local community well prepared, SVMs can enhance the temporal and geographical availability of sterile injecting equipment.
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On the dynamics of tapered vibro-impacting cantilever with tip mass
Energy Technology Data Exchange (ETDEWEB)
Gandhi, P. S.; Vyas, Vishal [Suman Mashruwala Advanced Microengineering Laboratory, Dept. of Mechanical Engineering, Indian Institute of Technology - Bombay, Mumai (India)
2017-01-15
This paper explores nonlinear dynamic behavior of vibro-impacting tapered cantilever with tip mass with regard to frequency response analysis. A typical frequency response curve of vibro-impacting beams displays well-known resonance frequency shift along with a hysteric jump and drop phenomena. We did a comprehensive parametric analysis capturing the effects of taper, tip-mass, stop location, and gap on the non-smooth frequency response. Analysis is presented in a non-dimensional form useful for other similar cases. Simulation results are further validated with corresponding experimental results for a few cases. Illustrative comparison of simulation results for varying parameters brings out several interesting aspects of variation in the nonlinear behavior.
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Directory of Open Access Journals (Sweden)
Łydżba Dariusz
2014-03-01
Full Text Available The needle probe test, as a thermal conductivity measurement method, has become very popular in recent years. In the present study, the efficiency of this methodology, for the case of composite materials, is investigated based on the numerical simulations. The material under study is a two-phase composite with periodic microstructure of “matrix-inclusion” type. Two-scale analysis, incorporating micromechanics approach, is performed. First, the effective thermal conductivity of the composite considered is found by the solution of the appropriate boundary value problem stated for the single unit cell. Next, numerical simulations of the needle probe test are carried out. In this case, two different locations of the measuring sensor are considered. It is shown that the “equivalent” conductivity, derived from the probe test, is strongly affected by the location of the sensor. Moreover, comparing the results obtained for different scales, one can notice that the “equivalent” conductivity cannot be interpreted as the effective one for the composites considered. Hence, a crude approximation of the effective property is proposed based on the volume fractions of constituents and the equivalent conductivities derived from different sensor locations.
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Morawski, Ireneusz; Voigtländer, Bert
2010-03-01
We present combined noncontact scanning force microscopy and tunneling current images of a platinum(111) surface obtained by means of a 1 MHz quartz needle sensor. The low-frequency circuit of the tunneling current was combined with a high-frequency signal of the quartz resonator enabling full electrical operation of the sensor. The frequency shift and the tunneling current were detected simultaneously, while the feedback control loop of the topography signal was fed using one of them. In both cases, the free signal that was not connected to the feedback loop reveals proportional-integral controller errorlike behavior, which is governed by the time derivative of the topography signal. A procedure is proposed for determining the mechanical oscillation amplitude by utilizing the tunneling current also including the average tip-sample work function.
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Needle Decompression of Tension Pneumothorax with Colorimetric Capnography.
Naik, Nimesh D; Hernandez, Matthew C; Anderson, Jeff R; Ross, Erika K; Zielinski, Martin D; Aho, Johnathon M
2017-11-01
The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression. Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002). Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
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Sugar export limits size of conifer needles
DEFF Research Database (Denmark)
Rademaker, Hanna; Zwieniecki, Maciej A.; Bohr, Tomas
2017-01-01
Plant leaf size varies by more than three orders of magnitude, from a few millimeters to over one meter. Conifer leaves, however, are relatively short and the majority of needles are no longer than 6 cm. The reason for the strong confinement of the trait-space is unknown. We show that sugars...... does not contribute to sugar flow. Remarkably, we find that the size of the active part does not scale with needle length. We predict a single maximum needle size of 5 cm, in accord with data from 519 conifer species. This could help rationalize the recent observation that conifers have significantly...
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CUDA accelerated simulation of needle insertions in deformable tissue
International Nuclear Information System (INIS)
Patriciu, Alexandru
2012-01-01
This paper presents a stiff needle-deformable tissue interaction model. The model uses a mesh-less discretization of continuum; avoiding thus the expensive remeshing required by the finite element models. The proposed model can accommodate both linear and nonlinear material characteristics. The needle-deformable tissue interaction is modeled through fundamental boundaries. The forces applied by the needle on the tissue are divided in tangent forces and constraint forces. The constraint forces are adaptively computed such that the material is properly constrained by the needle. The implementation is accelerated using NVidia CUDA. We present detailed analysis of the execution timing in both serial and parallel case. The proposed needle insertion model was integrated in a custom software that loads DICOM images, generate the deformable model, and can simulate different insertion strategies.
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A study on tip leakage vortex dynamics and cavitation in axial-flow pump
Energy Technology Data Exchange (ETDEWEB)
Shi, Lei; Zhang, Desheng; Jin, Yongxin; Shi, Weidong [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Esch, B P M van, E-mail: zds@ujs.edu.cn [Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands)
2017-06-15
The tip leakage flows and related cavitation in the tip region of an axial-flow pump were investigated in detail using the numerical and experimental methods. The numerical results of the pump model performance were in good agreement with experimental data. The flow structures in the tip clearance were clarified clearly with detailed data involving the axial velocity and turbulent kinetic energy. When depicting the feature of vortex core, the advanced vortex identification method λ {sub 2}-criterion was used. Simultaneously, the minimum tension criterion was also applied to predict the cavitation inception for different flow rates and it is consistent with the distributions of vorticity and pressure in the vortex core. The roll-up process of TLV is highly three-dimensional and the entrainment would follow different paths. Then, both the numerical and experimental approaches show the cavitation patterns for different cavitation conditions, and it also finds that slight cavitation would promote the development of tip leakage vortex (TLV) while the TLV seems to be eliminated for a low cavitation number, especially before a specific location of blade tip due to the blade loading change induced by cavitation possibly. (paper)
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Directory of Open Access Journals (Sweden)
Yohan Jung
2012-01-01
Full Text Available This paper presents a numerical investigation of the effects of a nonuniform tip clearance profile on the performance and flow field in a centrifugal compressor with a vaneless diffuser. This study focuses in particular on the magnitude and location of the wake. Six impellers with different tip clearance profiles were tested in the flow simulations. The accuracy of the numerical simulations was assessed by comparing the experimental data with the computational results for a system characterized by the original tip clearance. Although the performance improved for low tip clearances, a low tip clearance at the trailing edge improved the compressor performance more significantly than a low tip clearance at the leading edge. The flow field calculated for a system characterized by a low tip clearance at the trailing edge produced a more uniform velocity distribution both in the circumferential and in the axial directions at the impeller exit because the wake magnitude was reduced. As a consequence, this impeller provided a better potential for diffusion processes inside a vaneless diffuser.
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Chae, Younbyoung; Chang, Dong-Seon; Lee, Soon-Ho; Jung, Won-Mo; Lee, In-Seon; Jackson, Stephen; Kong, Jian; Lee, Hyangsook; Park, Hi-Joon; Lee, Hyejung; Wallraven, Christian
2013-03-01
Acupuncture is a therapeutic treatment that is defined as the insertion of needles into the body at specific points (ie, acupoints). Advances in functional neuroimaging have made it possible to study brain responses to acupuncture; however, previous studies have mainly concentrated on acupoint specificity. We wanted to focus on the functional brain responses that occur because of needle insertion into the body. An activation likelihood estimation meta-analysis was carried out to investigate common characteristics of brain responses to acupuncture needle stimulation compared to tactile stimulation. A total of 28 functional magnetic resonance imaging studies, which consisted of 51 acupuncture and 10 tactile stimulation experiments, were selected for the meta-analysis. Following acupuncture needle stimulation, activation in the sensorimotor cortical network, including the insula, thalamus, anterior cingulate cortex, and primary and secondary somatosensory cortices, and deactivation in the limbic-paralimbic neocortical network, including the medial prefrontal cortex, caudate, amygdala, posterior cingulate cortex, and parahippocampus, were detected and assessed. Following control tactile stimulation, weaker patterns of brain responses were detected in areas similar to those stated above. The activation and deactivation patterns following acupuncture stimulation suggest that the hemodynamic responses in the brain simultaneously reflect the sensory, cognitive, and affective dimensions of pain. This article facilitates a better understanding of acupuncture needle stimulation and its effects on specific activity changes in different brain regions as well as its relationship to the multiple dimensions of pain. Future studies can build on this meta-analysis and will help to elucidate the clinically relevant therapeutic effects of acupuncture. Copyright © 2013 American Pain Society. All rights reserved.
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Leiterer, Christian; Deckert-Gaudig, Tanja; Singh, Prabha; Wirth, Janina; Deckert, Volker; Fritzsche, Wolfgang
2015-05-01
Tip-enhanced Raman spectroscopy, a combination of Raman spectroscopy and scanning probe microscopy, is a powerful technique to detect the vibrational fingerprint of molecules at the nanometer scale. A metal nanoparticle at the apex of an atomic force microscope tip leads to a large enhancement of the electromagnetic field when illuminated with an appropriate wavelength, resulting in an increased Raman signal. A controlled positioning of individual nanoparticles at the tip would improve the reproducibility of the probes and is quite demanding due to usually serial and labor-intensive approaches. In contrast to commonly used submicron manipulation techniques, dielectrophoresis allows a parallel and scalable production, and provides a novel approach toward reproducible and at the same time affordable tip-enhanced Raman spectroscopy tips. We demonstrate the successful positioning of an individual plasmonic nanoparticle on a commercial atomic force microscope tip by dielectrophoresis followed by experimental proof of the Raman signal enhancing capabilities of such tips. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Enabling image fusion for a CT guided needle placement robot
Seifabadi, Reza; Xu, Sheng; Aalamifar, Fereshteh; Velusamy, Gnanasekar; Puhazhendi, Kaliyappan; Wood, Bradford J.
2017-03-01
Purpose: This study presents development and integration of hardware and software that enables ultrasound (US) and computer tomography (CT) fusion for a FDA-approved CT-guided needle placement robot. Having real-time US image registered to a priori-taken intraoperative CT image provides more anatomic information during needle insertion, in order to target hard-to-see lesions or avoid critical structures invisible to CT, track target motion, and to better monitor ablation treatment zone in relation to the tumor location. Method: A passive encoded mechanical arm is developed for the robot in order to hold and track an abdominal US transducer. This 4 degrees of freedom (DOF) arm is designed to attach to the robot end-effector. The arm is locked by default and is released by a press of button. The arm is designed such that the needle is always in plane with US image. The articulated arm is calibrated to improve its accuracy. Custom designed software (OncoNav, NIH) was developed to fuse real-time US image to a priori-taken CT. Results: The accuracy of the end effector before and after passive arm calibration was 7.07mm +/- 4.14mm and 1.74mm +/-1.60mm, respectively. The accuracy of the US image to the arm calibration was 5mm. The feasibility of US-CT fusion using the proposed hardware and software was demonstrated in an abdominal commercial phantom. Conclusions: Calibration significantly improved the accuracy of the arm in US image tracking. Fusion of US to CT using the proposed hardware and software was feasible.
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Does the effect of acupuncture depend on needling sensation and manipulation?
Choi, Yu-Jin; Lee, Jae-Eun; Moon, Won-Kyung; Cho, Seung-Hun
2013-06-01
Acupuncture sensation and manipulation have been considered to be an important component of acupuncture in traditional Asian medicine. However, there has been limited research as to whether acupuncture sensation is associated with therapeutic benefit. This study investigated the relationship between acupuncture sensation and analgesic effect according to acupuncture manipulation. Fifty-three healthy volunteers received three different forms of acupuncture in a single-blinded crossover design: superficial needling (0.3 cm), deep needling (2 cm) and needling with bi-directional rotation. The effects of acupuncture were evaluated by using the pressure pain threshold. Acupuncture sensation measurement was done in two ways. Both total acupuncture sensation and increase of the pressure pain threshold were maximum in needling with rotation, followed by deep needling and superficial needling. Repeated-measure analysis of variance (ANOVA) analysis was carried out to assess whether there was a significant difference; both showed significant difference (p = 0.000, 0.003). A paired sample t-test was carried out, which revealed that needling with rotation showed significant difference from both superficial needling and deep needling. Further, the correlation between the total acupuncture sensation and changes in pressure pain threshold were calculated using Pearson correlation; there was a significant correlation (p = 0.002, p = 0.013). Acupuncture sensation and pressure pain threshold increase according to the depth and rotation of acupuncture. Especially, both display significant increase with needle rotation. Further, there is a significant correlation between acupuncture needling sensation and increase in pressure pain threshold. It seems that needle rotation and acupuncture sensation play an important role in verifying the effect of acupuncture. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Fine needle aspiration cytology of cervicofacial actinomycosis
Directory of Open Access Journals (Sweden)
Venkatesh Kusuma
2008-01-01
Full Text Available Actinomycosis is a chronic infection caused by Actinomyces israelii, usually seen in immunocompromised patients or in the background of tissue injury. Cervicofacial actinomycosis presenting as a fixed jaw swelling in an elderly individual can mimic malignancy and pose a diagnostic dilemma. We report here a case of cervicofacial actinomycosis diagnosed by fine needle aspiration, along with a review of the relevant literature. A 60 year-old man presented with a gradually increasing 6 x 5 cm swelling in the left side of his jaw. The swelling was fixed, without any apparent sinus or abscess. Fine needle aspiration was diagnostic as it revealed colonies of actinomyces surrounded by polymorphs and chronic inflammatory cells. The histopathological study of the excised specimen confirmed the cytological findings. Fine needle aspiration is an effective tool in the diagnosis of actinomycosis although its documentation is rare. Difficulties in the management can be avoided by early diagnosis using the fine needle aspiration technique.
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Evaluation of heat transfer in acupuncture needles: convection and conduction approaches.
Tzou, Chieh-Han John; Yang, Tzyy-Yih; Chung, Ya-Chien
2015-04-01
Originating in ancient China, acupuncture using needles has been developed for thousands of years and has received attention for its reported medical remedies, such as pain relief and chronic disease treatment. Heat transfer through the needles, which might have effects on the biomechanism of acupuncture, providing a stimulus and regulating homeostasis, has never been studied. This article analyzes the significance of heat transfer through needles via convection and conduction, approached by means of computational analysis. The needle is a cylindrical body, and an axis symmetrical steady-state heat-transfer model that viscosity and static pressure was not applied. This article evaluates heat transfer via acupuncture needles by using five metal materials: silver, copper, brass, iron, and stainless steel. A silver needle of the type extensively applied in acupuncture can dissipate more than seven times as much heat as a stainless steel needle of the same type. Heat transfer through such a needle is significant, compared to natural body-energy consumption over a range of ambient temperatures. The mechanism by which heat flows in or out of the body through the needles may be crucial in the remedial efficacy of acupuncture. Copyright © 2015. Published by Elsevier B.V.
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Directory of Open Access Journals (Sweden)
Yue Hao
2017-01-01
Full Text Available The energy performance and radial force of a mixed flow pump with symmetrical and unsymmetrical tip clearance are investigated in this paper. As the tip clearance increases, the pump head and efficiency both decrease. The center of the radial force on the principal axis is located at the coordinate origin when the tip clearance is symmetrical, and moves to the third quadrant when the tip clearance is unsymmetrical. Analysis results show that the total radial force on the principal axis is closely related to the fluctuation of mass flow rate in each single flow channel. Unsteady simulations show that the dominant frequencies of radial force on the hub and blade correspond to the blade number, vane number, or double blade number because of the rotor stator interaction. The radial force on the blade pressure side decreases with the tip clearance increase because of leakage flow. The unsymmetrical tip clearances in an impeller induce uneven leakage flow rate and then result in unsymmetrical work ability of each blade and flow pattern in each channel. Thus, the energy performance decreases and the total radial force increases for a mixed flow pump with unsymmetrical tip clearance.
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Return Rates for Needle Exchange Programs: A Common Criticism Answered
Directory of Open Access Journals (Sweden)
Ksobiech Kate
2004-04-01
Full Text Available Abstract This study searched the available needle exchange program (NEP literature for return rate data. A total of 26 articles were found. The overall worldwide return rate was 90%, although this ranged from a low of 15% to a high of 112%. U.S. NEP return rates were gathered from only eight studies, indicating a clear need for more data, although U.S. return rates were comparable to those from NEPs outside of the U.S. One underlying assumption made by opponents of NEPs is that IDUs will not return needles to the distribution site, thereby potentially increasing the risk of health problems to the surrounding community from exposure to contaminated needles. This study's results suggest that NEPs are relatively successful in taking in used needles, although it is generally unclear where the needles were originally acquired, and if IDUs return their own needles, or are returning needles for a social network. Ways for AIDS Service Organizations to capitalize on these brief encounters with IDUs, as well as public policy implications of the findings, are discussed.
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Fabrication and buckling dynamics of nanoneedle AFM probes
Energy Technology Data Exchange (ETDEWEB)
Beard, J D; Gordeev, S N, E-mail: jdb28@bath.ac.uk [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)
2011-04-29
A new method for the fabrication of high-aspect-ratio probes by electron beam induced deposition is described. This technique allows the fabrication of cylindrical 'nanoneedle' structures on the atomic force microscope (AFM) probe tip which can be used for accurate imaging of surfaces with high steep features. Scanning electron microscope (SEM) imaging showed that needles with diameters in the range of 18-100 nm could be obtained by this technique. The needles were shown to undergo buckling deformation under large tip-sample forces. The deformation was observed to recover elastically under vertical deformations of up to {approx} 60% of the needle length, preventing damage to the needle. A technique of stabilizing the needle against buckling by coating it with additional electron beam deposited carbon was also investigated; it was shown that coated needles of 75 nm or greater total diameter did not buckle even under tip-sample forces of {approx} 1.5 {mu}N.
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Sharma, Deepak; Farahbakhsh, Nazanin; Tabatabaii, Seyyed Ahmad
2018-02-15
Central catheters are known as "life lines" in intensive care units and are used frequently in neonatal intensive care unit (NICU) for multiple indications. The central catheters used in NICU includes umbilical venous catheter (UVC), umbilical arterial catheter (UAC) and peripherally inserted central catheter (PICC) lines. The tip of these central lines needs to be in a correct position as malpositioned central line tips lead to many neonatal complications. Radiograph either abdomen or chest is the most widely used modality for locating the tip of the central catheter. There are many disadvantages of radiographic confirmation of tip position and recently ultrasound (USG)/echocardiography has been used for localization of catheter tip. USG provides real-time assessment of the tip position with other added advantages like no radiation exposure, need for minimal training for performing USG, minimal handling of the neonate, identification of migration of central lines and making repositioning of central lines under USG guidance. The present evidence supports the use of USG/Echo for localization of central catheter tip and USG has shown to have good sensitivity, specificity, positive predictive value and negative predictive value when compared with a radiograph. In this review, we discuss about the role of USG/Echo in the identification of tip of central catheters in neonatal care.
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Safety Tips: Basketball (For Parents)
... Staying Safe Videos for Educators Search English Español Safety Tips: Basketball KidsHealth / For Parents / Safety Tips: Basketball ... make sure they follow these tips. Why Basketball Safety Is Important Fortunately, very few basketball injuries are ...
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An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy
International Nuclear Information System (INIS)
Hong, J; Dohi, T; Hashizume, M; Konishi, K; Hata, N
2004-01-01
A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target
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Crowe, John B; Lanzarotta, Adam; Witkowski, Mark R; Andria, Sara E
2015-07-01
Suspect hypodermic needles and syringes were seized from an unlicensed individual who was allegedly injecting patients with silicone (polydimethylsiloxane [PDMS]) for cosmetic enhancement. Since control syringe barrels and needles often contain an interfering PDMS lubricant, a risk for false positives of foreign PDMS exists. The focus of this report was to minimize this risk and determine a quick and reliable test for the presence of blood in PDMS matrices. Using ATR-FT-IR spectroscopy, the risk for false-positive identification of foreign PDMS was reduced by (i) overfilling the sampling aperture to prevent spectral distortions and (ii) sampling a region of the suspect syringe/needle assembly where manufacturer-applied PDMS is not typically located. Analysis for blood indicated that the Teichman microchemical test was effective for detecting blood in the presence of PDMS. Overall, detecting PDMS established intent and detecting blood established that the needle containing the PDMS had been used for injection. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
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A new robotic needle insertion method to minimise attendant prostate motion
International Nuclear Information System (INIS)
Lagerburg, Vera; Moerland, Marinus A.; Vulpen, Marco van; Lagendijk, Jan J.W.
2006-01-01
Background and purpose: The purpose of this study is to investigate the efficacy of a new needle insertion method (tapping instead of pushing) in reducing attendant tissue motion. This can be useful in applications where tissue motion due to needle insertion is problematic such as e.g. MRI-guided prostate brachytherapy and breast biopsies. In this study we will focus on prostate motion due to needle insertion. Material and methods: Prostate motion due to needle insertion was measured in 30 patients, who were transperineally implanted with fiducial gold markers for position verification in prostate intensity modulated radiotherapy. In total 32 needles were manually pushed into the prostate and 29 were tapped with a prototype robotic system. The prostate motion in the cranio-caudal direction was measured on the video record of the ultrasound images. Differences in prostate motion between the two needle insertion methods were analysed making use of SPSS. Results: The mean prostate motion was 5.6 mm (range 0.3-21.6) when the needle was pushed and 0.9 mm (range 0-2.0) when the needle was tapped into the prostate (p < 0.001). Conclusion: Prostate motion was significantly less when the needle was tapped into the prostate compared to when the needle was pushed. This result is important for the development of a tapping, MRI-guided, prostate implant robotic system
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... the liver). Portal hypertension can also occur in children, although children are much less likely to require a TIPS. ... intentionally to solve the problem. Although extremely rare, children may also require a TIPS procedure. TIPS in ...
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Tips and Tricks of Percutaneous Gastrostomy Under Image Guidance in Patients with Limited Access
Energy Technology Data Exchange (ETDEWEB)
Marcy, Pierre-Yves; Figl, Andrea; Thariat, Juliette [Sophia Antipolis University, Nice cedex (France); Lacout, Alexis [Centre Me' dico-Chirurgical, Aurillac (France)
2011-10-15
We read with great interest the article by Chan et al. (1) in the March issue of Korean Journal of Radiology on their experience of modified radiology-guided percutaneous gastrostomy (MRPG). The authors proposed a technique to access the stomach in patients with upper digestive tract obstruction (UDTO). Following marking a patient's left liver inferior margin and room air-colonography, the authors punctured the gastric area using a 21G fine needle under X-ray guidance and withdrew their syringe gradually while injecting contrast medium. We noted that the gastrostomy may be performed using a 0.0035-inch hydrophilic guide wire and a 6.5-Fr angled catheter in almost 100% of patients contraindicated for endoscopy gastrostomy, including those with tortuous or tight cervical stenosis (2). In patients with a collapsed stomach, orally administered effervescent sodium bicarbonate powder can produce sufficient gas in the stomach to allow for a percutaneous needle puncture. In UDTO patients, diatrizoate meglumine can be directly injected into the gastric lumen under ultrasound (US) guidance, as reported by Pugash et al. (3) in 1995. Since the stomach appears collapsed with apposed multi-layer walls and virtual lumen on US, the needle tip is hardly seen. In such circumstances, after having transfixed the stomach with a 21G Chiba needle, further gradual needle withdrawing is performed under fluoroscopic guidance while injecting small amounts of diatrizoate meglumine until a ruga pattern is seen. Moreover, a cancer patient's subcutaneous fat is often absent and the anterior gastric wall is close to the abdominal wall. High frequency US monitoring does improve needle visualization in such a circumstance. Conversely, in obese patients, back- and forth motions of the needle stylet under Doppler color US guidance clearly improves needle visualization. We noted that by using this technique we successfully performed percutaneous fluoroscopy gastrostomy (PFG) in two partially
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Tips and Tricks of Percutaneous Gastrostomy Under Image Guidance in Patients with Limited Access
International Nuclear Information System (INIS)
Marcy, Pierre-Yves; Figl, Andrea; Thariat, Juliette; Lacout, Alexis
2011-01-01
We read with great interest the article by Chan et al. (1) in the March issue of Korean Journal of Radiology on their experience of modified radiology-guided percutaneous gastrostomy (MRPG). The authors proposed a technique to access the stomach in patients with upper digestive tract obstruction (UDTO). Following marking a patient's left liver inferior margin and room air-colonography, the authors punctured the gastric area using a 21G fine needle under X-ray guidance and withdrew their syringe gradually while injecting contrast medium. We noted that the gastrostomy may be performed using a 0.0035-inch hydrophilic guide wire and a 6.5-Fr angled catheter in almost 100% of patients contraindicated for endoscopy gastrostomy, including those with tortuous or tight cervical stenosis (2). In patients with a collapsed stomach, orally administered effervescent sodium bicarbonate powder can produce sufficient gas in the stomach to allow for a percutaneous needle puncture. In UDTO patients, diatrizoate meglumine can be directly injected into the gastric lumen under ultrasound (US) guidance, as reported by Pugash et al. (3) in 1995. Since the stomach appears collapsed with apposed multi-layer walls and virtual lumen on US, the needle tip is hardly seen. In such circumstances, after having transfixed the stomach with a 21G Chiba needle, further gradual needle withdrawing is performed under fluoroscopic guidance while injecting small amounts of diatrizoate meglumine until a ruga pattern is seen. Moreover, a cancer patient's subcutaneous fat is often absent and the anterior gastric wall is close to the abdominal wall. High frequency US monitoring does improve needle visualization in such a circumstance. Conversely, in obese patients, back- and forth motions of the needle stylet under Doppler color US guidance clearly improves needle visualization. We noted that by using this technique we successfully performed percutaneous fluoroscopy gastrostomy (PFG) in two partially
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[King Injo's disease and burnt needle therapy].
Kim, In-Sook
2004-12-01
This paper investigates an interrelationship between burnt needle therapy and King Injo's disease. From 1633 (Year 11 in King Injo's reign) to May 5, 1649 (Year 27 in King Injo's reign), right before his death, King Injo was treated with burnt needles by Yi Hyeongik, an acupuncturist when the king had health problems. This study arises from two questions: why was King Injo often treated with burnt needles? and what effect did burnt needles have?Burnt needle therapy is a combined form of acupuncture and moxibustion. Yi Hyeongik was famous for eradicating pathogenic factors. He was appointed as a doctor in the Royal Hospital. The medical definition for pathogenic factors is that they are disease-causing factors. Understanding the pathogenic factor for King Injo's disease could make it possible to find the interrelationship between burnt needles and the king's disease. In the Joseon ear, the prevalent belief about diseases was that diseases could be caused by homeopathic magic. Some people thought homeopathic magic caused King Injo's disease. The actual reasons for King Injo's disease were the participation in the excessive rites of Queen Mother Inmok's funeral and the constant oppression from the Ching Dynasty after disgraceful defeat in the war. When King Injo started to be sick, homeopathic magic cases were found in the royal palace. The king's incurable disease was believed to have happened as a result of homeopathic magic. King Injo's suspicion toward Princess Jeongmyeong derived from her mother, Queen Mother Inmok. Moral justification for King Injo's coup was Gwanghaegun or Prince Gwanghae's immoral conduct toward Queen Mothe Inmok. After he was installed, King Injo obeyed the Queen Mother and showed her every attention. Meanwhile, he treated Princess Jeongmyeong with respect, maximized the moral justification for the coup, and solidified the royal authority. However, constant rebellions and treasons threatened King Injo. The king suspected that Queen Mother
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Fine Needle Aspiration Biopsy in a Rural Family Practice
African Journals Online (AJOL)
ultrasound scan. A 21-gauge 1½-inch or 23-gauge 1¼-inch needle, attached to a 10-mL disposable plastic syringe, was used for FNAB of superficial masses. For percutaneous FNAB of deep-seated organs and masses, a 23 gauge 1¼-inch needle or 3½-inch spinal needle was used. The aspirate was spread on slides and ...
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Structure of the Yersinia pestis tip protein LcrV refined to 1.65 Å resolution
International Nuclear Information System (INIS)
Chaudhury, Sukanya; Battaile, Kevin P.; Lovell, Scott; Plano, Gregory V.; De Guzman, Roberto N.
2013-01-01
Here, the crystal structure of Yersinia pestis tip protein LcrV is reported at a resolution of 1.65 Å. The human pathogen Yersinia pestis requires the assembly of the type III secretion system (T3SS) for virulence. The structural component of the T3SS contains an external needle and a tip complex, which is formed by LcrV in Y. pestis. The structure of an LcrV triple mutant (K40A/D41A/K42A) in a C273S background has previously been reported to 2.2 Å resolution. Here, the crystal structure of LcrV without the triple mutation in a C273S background is reported at a higher resolution of 1.65 Å. Overall the two structures are similar, but there are also notable differences, particularly near the site of the triple mutation. The refined structure revealed a slight shift in the backbone positions of residues Gly28–Asn43 and displayed electron density in the loop region consisting of residues Ile46–Val63, which was disordered in the original structure. In addition, the helical turn region spanning residues Tyr77–Gln95 adopts a different orientation
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[Research progress of needles with knife-edge for carotid cardiac syndrome].
Tan, Lingqiong; Zhao, Yanling
2015-04-01
According to topographic anatomy, pathogenesis and by retrieving, summarizing and analyzing literature regarding needle-knife and needles with knife-edge for carotid cardiac syndrome, it is found out that clinical misdiagnosis rate of carotid cardiac syndrome is considerably high. Needle-knife and needles with knife-edge could significantly improve the clinical symptoms of carotid cardiac syndrome, showing characteristic and advantage in treatment, but it is deficient in technique standard and efficacy criteria that should be united and authoritative. Researches regarding pathogenesis of carotid cardiac syndrome are not systematic. Clinical observation regarding long-term efficacy and relapse of needle-knife and needles with knife-edge treatment is rare. It is believed that the awareness on carotid cardiac syndrome should be increased to reduce misdiagnosis; scientific and standardized technique standard and efficacy criteria should be established; systematic and comprehensive researches regarding mechanism of needle-knife and needles with knife-edge for carotid cardiac syndrome should be launched; besides, clinical discussion regarding its long-term efficacy should start to provide a better clinical guideline.
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Tip off the HAT- Epigenetic control of learning and memory by Drosophila Tip60.
Xu, Songjun; Elefant, Felice
2015-01-01
Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders.
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Extrapeural locating method: significance in CT-guided transthoracic pulmonary biopsy
International Nuclear Information System (INIS)
Tang Guangjian; Wang Rengui; Liu Jianxin; Sun Jingtao
2008-01-01
Objective: To evaluate the usefulness of extrapleural locating method in CT-guided transthoracic pulmonary biopsy to prevent or reduce the size of peumothorax. Methods: One hundred and fifteen cases of CT-guided transthoracic pulmonary biopsy with the pulmonary lesions not in direct contact with the pleura were selected. Of 115 cases, 46 were performed with extrapleural locating method (EPL) and 69 cases with lesion edge locating method (LEL). Taking the maximum distance between the partial and visceral pleura (MPVD) measured on the CT image after the procedure as the index of the volume of pneumothorax. The incidence and volume of pneumothorax of both groups were compared and statistically analysed with R x C Chi-Square test. The retention time of the biopsy needle in the lung parenchyma of the two group was documented and the average time was calculated in each group. Results: The incidence of pneumothorax was 45.7% (21/46), median 0.4 cm with EPL group, and 66.7% (46/69) and median 0.3cm with LEL group. When the distance between the lesion and pleura was equal or smaller than 2 cm (≤2cm), the incidence of pneumothorax was 39.4% (13/33) with EPL group and 73.2% (30/41) with LEL group, and the difference of incidence and volume of the pneumothorax between two groups was statistically significant(χ 2 =9.981, P=0.019). When the distance was larger than 2 cm (>2 cm), the incidence and volume of pneumothorax between two groups were not significant statistically. The average retention time of the biopsy needle in the lung parenchyma was (7.2 ± 1.8) s with EPL group and (58.3 ± 11.6) s with LEL group. Conclusion: The extrapleural locating method can reduce effectively the retention time of the biopsy needle in the lung parenchyma and the incidence and volume of pneumothorax in CT-guided transthoracic pulmonary biopsy. (authors)
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Corder, Lloyd E.; And Others
This manual of telephone behavior tips for business and sales professionals offers ways to handle the disgruntled caller and makes suggestions on topics relevant to the telephone. The manual is divided into the following sections and subsections: (1) Common Courtesy (staff tips, answering the telephone, screening calls, transferring calls, taking…
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International Nuclear Information System (INIS)
Lee, Sang Woo; Cheon, Joo Hong; Zhang, Qiang
2014-01-01
Highlights: • The effect of full coverage (FC) winglets on tip leakage aerodynamics is tested. • A qualitative tip gap flow model for the FC winglet is suggested. • The FC winglet of w/p = 10.55% is considered an optimal one for the plane tip. -- Abstract: The effect of full coverage (FC) winglets on tip leakage aerodynamics over the plane tip in a turbine cascade has been investigated with the variation of winglet width (w) up to w/p = 15.83% for a tip gap-to-span (chord) ratio of h/s = 1.36% (h/c = 2.0%). A qualitative tip gap flow model for the FC winglet is suggested on the bases of the near-tip surface flow visualizations. As w/p increases, the passage vortex tends to be weakened meanwhile the tip leakage vortex becomes stronger and wall-jet-like. With an increment of w/p, the mass-averaged aerodynamic loss all over the measurement plane decreases steeply up to w/p = 10.55% and then becomes almost unchanged. Thus, the FC winglet of w/p = 10.55% is considered an optimal one for the plane tip. With respect to the baseline plane tip without winglet, the maximum mass-averaged loss reduction by installing the FC winglet on the plane tip is still somewhat smaller than that by employing the cavity squealer rim on the plane tip surface
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Risk of needle stick injuries in health care workers: bad habits (recapping needles) last long.
Rogowska-Szadkowska, Dorota; Stanisławowicz, Małgorzata; Chlabicz, Sławomir
2010-01-01
In order to assess the nurses' knowledge concerning the risk of hepatitis B and C viruses or human immunodeficiency virus infection while performing their professional duties, an anonymous questionnaire developed by the authors was distributed in 2008. Surprisingly 64% respondents occasionally recapping needles after injections, although they know the procedures which are obligatory at the ward. The first step in preventing percutaneous injuries should focus on efforts to eliminate the practice of recapping needles, though education and convenient placement of puncture-resistant containers for the disposal of used sharps.
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Location audio simplified capturing your audio and your audience
Miles, Dean
2014-01-01
From the basics of using camera, handheld, lavalier, and shotgun microphones to camera calibration and mixer set-ups, Location Audio Simplified unlocks the secrets to clean and clear broadcast quality audio no matter what challenges you face. Author Dean Miles applies his twenty-plus years of experience as a professional location operator to teach the skills, techniques, tips, and secrets needed to produce high-quality production sound on location. Humorous and thoroughly practical, the book covers a wide array of topics, such as:* location selection* field mixing* boo
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Kavrut Ozturk, Nilgun; Kavakli, Ali Sait
2017-08-01
This prospective randomized study compared the coracoid and retroclavicular approaches to ultrasound-guided infraclavicular brachial plexus block (IBPB) in terms of needle tip and shaft visibility and quality of block. We hypothesized that the retroclavicular approach would increase needle tip and shaft visibility and decrease the number of needle passes compared to the coracoid approach. A total of 100 adult patients who received IBPB block for upper limb surgery were randomized into two groups: a coracoid approach group (group C) and a retroclavicular approach group (group R). In group C, the needle was inserted 2 cm medial and 2 cm inferior to the coracoid process and directed from ventral to dorsal. In group R, the needle insertion point was posterior to the clavicle and the needle was advanced from cephalad to caudal. All ultrasound images were digitally stored for analysis. The primary aim of the present study was to compare needle tip and shaft visibility between the coracoid approach and retroclavicular approach in patients undergoing upper limb surgery. The secondary aim was to investigate differences between the two groups in the number of needle passes, sensory and motor block success rates, surgical success rate, block performance time, block performance-related pain, patient satisfaction, use of supplemental local anesthetic and analgesic, and complications. Needle tip visibility and needle shaft visibility were significantly better in group R (p = 0.040, p = 0.032, respectively). Block performance time and anesthesia-related time were significantly shorter in group R (p = 0.022, p = 0.038, respectively). Number of needle passes was significantly lower in group R (p = 0.044). Paresthesia during block performance was significantly higher in group C (p = 0.045). There were no statistically significant differences between the two groups in terms of sensory or motor block success, surgical success, block-related pain, and patient satisfaction
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Ahmed, Zubair M; Goodyear, Richard; Riazuddin, Saima; Lagziel, Ayala; Legan, P Kevin; Behra, Martine; Burgess, Shawn M; Lilley, Kathryn S; Wilcox, Edward R; Riazuddin, Sheikh; Griffith, Andrew J; Frolenkov, Gregory I; Belyantseva, Inna A; Richardson, Guy P; Friedman, Thomas B
2006-06-28
Sound and acceleration are detected by hair bundles, mechanosensory structures located at the apical pole of hair cells in the inner ear. The different elements of the hair bundle, the stereocilia and a kinocilium, are interconnected by a variety of link types. One of these links, the tip link, connects the top of a shorter stereocilium with the lateral membrane of an adjacent taller stereocilium and may gate the mechanotransducer channel of the hair cell. Mass spectrometric and Western blot analyses identify the tip-link antigen, a hitherto unidentified antigen specifically associated with the tip and kinocilial links of sensory hair bundles in the inner ear and the ciliary calyx of photoreceptors in the eye, as an avian ortholog of human protocadherin-15, a product of the gene for the deaf/blindness Usher syndrome type 1F/DFNB23 locus. Multiple protocadherin-15 transcripts are shown to be expressed in the mouse inner ear, and these define four major isoform classes, two with entirely novel, previously unidentified cytoplasmic domains. Antibodies to the three cytoplasmic domain-containing isoform classes reveal that each has a different spatiotemporal expression pattern in the developing and mature inner ear. Two isoforms are distributed in a manner compatible for association with the tip-link complex. An isoform located at the tips of stereocilia is sensitive to calcium chelation and proteolysis with subtilisin and reappears at the tips of stereocilia as transduction recovers after the removal of calcium chelators. Protocadherin-15 is therefore associated with the tip-link complex and may be an integral component of this structure and/or required for its formation.
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Currently, Swiss Needle Cast (SNC) is causing an epidemic west of the Oregon Coast Range from Coos Bay to Astoria. The most severely infected Douglas-fir trees are located on BLM land and Stimson Lumber plantations in Tillamook where environmental conditions are highly favorable ...
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[Special penetration needling for refractory peripheral facial paralysis].
Cao, Rongjuan; Qiu, Xiaohu; Xie, Xiaokun
2018-03-12
To observe the clinical effect difference between special penetration needling and conventional penetration needling for the refractory peripheral facial paralysis. A total of 97 patients with intractable facial paralysis were randomized into an observation group (49 cases and 2 dropping) and a control group (48 cases and 4 dropping). In the observation group, special penetration needling at an angle about 45° between the penetration needle and paralysis muscle bundle was used, Yangbai (GB 14) through Touwei (ST 8), Yangbai (GB 14) through Shangxing (GV 23), Sizhukong (TE 23) through Yuyao (EX-HN 4), Qianzhen (Extra) through Yingxiang (LI 20), mutual penetration between Yingxiang (LI 20) and Jiache (ST 6). Conventional penetration needling was applied in the control group, Yangbai (GB 14) through Yuyao (EX-HN 4), Cuanzhu (BL 2) through Yuyao (EX-HN 4), mutual penetration between Dicang (ST 4) and Jiache (ST 6), Qianzheng (Extra) through Dicang (ST 4), Sibai (ST 2) through Yingxiang (LI 20). Three groups of electroacupuncture (discontinuous wave, 1 Hz) with tolerance were connected respectively in the two groups, Yangbai (GB 14) and Sizhukong (TE 23), Yangbai (GB 14) and Qianzheng (Extra), Yingxiang (LI 20) and Jiache (ST 6) in the observation group, Yangbai (GB 14) and Cuanzhu (BL 2), Dicang (ST 4) and Jiache (ST 6), Qianzheng (Extra) and Sibai (ST 2) in the control group. TDP was applied in the two groups at the affected Yifeng (TE 17), Jiache (ST 6) and Qianzheng (Extra), which were around the ear. Perpendicular insertion was used at Yifeng (TE 17) at the affected side and Hegu (LI 4) at the healthy side and bilateral Zusanli (ST 36). The needles were retained for 30 min. The treatment was given for 3 courses, once a day and 10 days as a course, 5 days at the interval. House-Brackmann (H-B) facial nerve grading score was recorded before and after treatment. The clinical effects were compared. The H-B scores after treatment in the two groups were higher than
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Energy Technology Data Exchange (ETDEWEB)
TermehYousefi, Amin, E-mail: at.tyousefi@gmail.com [Department of Human Intelligence Systems, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology (Kyutech) (Japan); Bagheri, Samira; Shahnazar, Sheida [Nanotechnology & Catalysis Research Centre (NANOCAT), IPS Building, University Malaya, 50603 Kuala Lumpur (Malaysia); Rahman, Md. Habibur [Department of Computer Science and Engineering, University of Asia Pacific, Green Road, Dhaka-1215 (Bangladesh); Kadri, Nahrizul Adib [Department of Biomedical Engineering, Faculty of Engineering, University Malaya, 50603 Kuala Lumpur (Malaysia)
2016-02-01
Carbon nanotubes (CNTs) are potentially ideal tips for atomic force microscopy (AFM) due to the robust mechanical properties, nanoscale diameter and also their ability to be functionalized by chemical and biological components at the tip ends. This contribution develops the idea of using CNTs as an AFM tip in computational analysis of the biological cells. The proposed software was ABAQUS 6.13 CAE/CEL provided by Dassault Systems, which is a powerful finite element (FE) tool to perform the numerical analysis and visualize the interactions between proposed tip and membrane of the cell. Finite element analysis employed for each section and displacement of the nodes located in the contact area was monitored by using an output database (ODB). Mooney–Rivlin hyperelastic model of the cell allows the simulation to obtain a new method for estimating the stiffness and spring constant of the cell. Stress and strain curve indicates the yield stress point which defines as a vertical stress and plan stress. Spring constant of the cell and the local stiffness was measured as well as the applied force of CNT-AFM tip on the contact area of the cell. This reliable integration of CNT-AFM tip process provides a new class of high performance nanoprobes for single biological cell analysis. - Graphical abstract: This contribution develops the idea of using CNTs as an AFM tip in computational analysis of the biological cells. The proposed software was ABAQUS 6.13 CAE/CEL provided by Dassault Systems. Finite element analysis employed for each section and displacement of the nodes located in the contact area was monitored by using an output database (ODB). Mooney–Rivlin hyperelastic model of the cell allows the simulation to obtain a new method for estimating the stiffness and spring constant of the cell. Stress and strain curve indicates the yield stress point which defines as a vertical stress and plan stress. Spring constant of the cell and the local stiffness was measured as well
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Aperiodicity Correction for Rotor Tip Vortex Measurements
Ramasamy, Manikandan; Paetzel, Ryan; Bhagwat, Mahendra J.
2011-01-01
The initial roll-up of a tip vortex trailing from a model-scale, hovering rotor was measured using particle image velocimetry. The unique feature of the measurements was that a microscope was attached to the camera to allow much higher spatial resolution than hitherto possible. This also posed some unique challenges. In particular, the existing methodologies to correct for aperiodicity in the tip vortex locations could not be easily extended to the present measurements. The difficulty stemmed from the inability to accurately determine the vortex center, which is a prerequisite for the correction procedure. A new method is proposed for determining the vortex center, as well as the vortex core properties, using a least-squares fit approach. This approach has the obvious advantage that the properties are derived from not just a few points near the vortex core, but from a much larger area of flow measurements. Results clearly demonstrate the advantage in the form of reduced variation in the estimated core properties, and also the self-consistent results obtained using three different aperiodicity correction methods.
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DEFF Research Database (Denmark)
Kurz-Besson, C.; Coûteaux, M.M.; Berg, Bjørn
2006-01-01
The forest floor needle mass and the decomposition rates of pine needle litter in a European climate transect were studied in order to estimate the impact of climate change on forest soil carbon sequestration. Eight pine forests preserved from fire were selected along a climatic latitudinal...... gradient from 40° to 60° N, from Spain and Portugal to Sweden. The forest floor (Oi and Oe layers) was sorted into five categories of increasing decomposition level according to morphological criteria. The needle mass loss in each category was determined using a linear mass density method. The needle...... and a recalcitrant one. NF was correlated with actual evapotranspiration (AET) whereas the decomposition parameters (decomposition rate of the decomposable fraction, first year mass loss, forest floor needle mass, age of the most-decomposed category) were related to a combined response function to climate (CRF...
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DEFF Research Database (Denmark)
Shin, K. W.; Andersen, Poul
2015-01-01
The blade tip loading is often reduced as an effort to restrain sheet and tip vortex cavitation in the design of marine propellers. This CFD analysis demonstrates that an excessive reduction of the tip loading can cause cloud cavitation responsible for much of noise and surface erosion. Detached...
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[Meta-analysis of needle-knife treatment on cervical spondylosis].
Kan, Li-Li; Wang, Hai-Dong; Liu, An-Guo
2013-11-01
To assess the efficacy of cervical spondylosis by needle-knife treatment according to the correlated literature of RCT,to compare advantages of needle-knife treatment. Randomized Controlled Trials about needle-knife treatment of cervical spondylosis were indexed from Chinese HowNet (CNKI) and Wanfang (WF) from 2000 to 2012, then were analyzed the efficacy by Review Manager 5.1 software. A total of 13 RCT literatures and 1 419 patients were included. The methods of included studies were poor in quality evaluation because of large sample and multi-center RCT studies was lacked, randomization method was not accurate enough, diagnostic criteria and efficacy evaluation were various, only four studies described long-term efficacy, most of the literature didn't describe the adverse event and fall off,all studies did not use the blind method. The Meta analysis outcome showed overall efficiency of needle-knife therapy was better than acupuncture and traction. Needle-knife therapy compared with Acupuncture, the total RR = 0.19, 95% confidence interval was (0.15, 0.24), P knife therapy is higher;compared with traction therapy, although,needle-knife therapy has a high overall effectiveness, but because of the loss of total sample size, the outcome RCT researches to confirm.
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Dry needling in lateral epicondylitis: a prospective controlled study.
Uygur, Esat; Aktaş, Birol; Özkut, Afşar; Erinç, Samet; Yilmazoglu, Emime Gül
2017-11-01
Lateral epicondylitis (LE), a common disease, especially in middle age, causes decreased productivity and economic losses. The first-line treatment for LE is conservative and consists of topical and oral anti-inflammatory drugs, ice application, and brace use. If the first-line treatment fails, second-line treatment modalities, which are generally invasive, are offered. Second-line therapeutic regimens include saline, corticosteroid, or platelet-rich plasma injections. Dry needling is relatively new. We hypothesized that dry needling would be at least as effective as first-line treatment for LE. We compared the outcomes of first-line treatment and dry needling. The study allocated 110 patients into groups using online randomization software. After completing the Patient-rated Tennis Elbow Evaluation (PRTEE), patients in group I received dry needling, whereas those in group II received first-line treatment, consisting of ibuprofen 100 mg twice a day and a proximal forearm brace. The patients were evaluated after three weeks and six months. The study ultimately analyzed 92 patients. Although both treatment methods were effective at three weeks, dry needling was significantly more effective than the first-line treatment at six months. Because of the low complication rate, dry needling is a safe method, and it might be an effective treatment option for LE.
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King Injo's Disease and Burnt Needle Therapy
Directory of Open Access Journals (Sweden)
KIM In-Sook
2004-12-01
Full Text Available This paper investigates an interrelationship between burnt needle therapy(번침 and King Injo'sdisease. From 1633 (Year 11 in King Injo's reign to May 5, 1649 (Year 27 King in Injo's reign, right before his death, King Injo(인조 was treated with burnt needles by Yi Hyeongik(이형익, an acupuncturist when the king had health problems. This study arises from two questions: why was King Injo often treated with burnt needles? and what effect did burnt needles have? Burnt needle therapy is a combined form of acupuncture and moxibustion. Yi Hyeongik was famous for eradicating pathogenic factors. He was appointed as a doctor in the Royal Hospital. The medical definition for pathogenic factors is that they are disease-causing factors. Understanding the pathogenic factor for King Injo's disease could make it possible to find the interrelationship between burnt needles and the king's disease. In the Joseon era, the prevalent belief about diseases was that diseases could be caused by homeopathic magic. Some people thought homeopathic magic caused King Injo's disease. The actual reasons for King Injo's disease were the participation in the excessive rites of Queen Mother Inmok's funeral and the constant oppression from the Ching Dynasty after disgraceful defeat in the war. When King Injo started to be sick, homeopathic magic cases were found in the royal palace. The king's incurable disease was believed to have happened as a result of homeopathic magic. King Injo's suspicion toward Princess Jeongmyeong(정명공주 derived from her mother, Queen Mother Inmok(인목대비. Moral justification for King Injo's coup was Gwanghaegun(광해군 or Prince Gwanghae's immoral conduct toward Queen Mother Inmok. After he was installed, King Injo obeyed the Queen Mother and showed her every attention. Meanwhile, he treated Princess Jeongmyeong with respect, maximized the moral justification for the coup, and solidified the royal authority. However, constant
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Dorr, H.G.; Zabransky, S.; Keller, E.; Otten, B.J.; Partsch, C.J.; Nyman, L.; Gillespie, B.K.; Lester, N.R.; Wilson, A.M.; Hyren, C.; Kuijck, M.A. van; Schuld, P.; Schoenfeld, S.L.
2003-01-01
The clinical safety, use and pharmacokinetics of a new needle-free device for delivery of growth hormone (GH) were compared with those of conventional needle injection devices. In an open-label, randomized, 4-period crossover study, 18 healthy adults received single subcutaneous injections of
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Development and validation of a viscoelastic and nonlinear liver model for needle insertion
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Yo [Waseda University, Consolidated Research Institute for Advanced Science and Medical Care, Shinjuku, Tokyo (Japan); Onishi, Akinori; Hoshi, Takeharu; Kawamura, Kazuya [Waseda University, Graduate School of Science and Engineering, Shinjuku (Japan); Hashizume, Makoto [Kyushu University Hospital, Center for the Integration of Advanced Medicine and Innovative Technology, Fukuoka (Japan); Fujie, Masakatsu G. [Waseda University, Graduate School of Science and Engineering, Faculty of Science and Engineering, Shinjuku (Japan)
2009-01-15
The objective of our work is to develop and validate a viscoelastic and nonlinear physical liver model for organ model-based needle insertion, in which the deformation of an organ is estimated and predicted, and the needle path is determined with organ deformation taken into consideration. First, an overview is given of the development of the physical liver model. The material properties of the liver considering viscoelasticity and nonlinearity are modeled based on the measured data collected from a pig's liver. The method to develop the liver model using FEM is also shown. Second, the experimental method to validate the model is explained. Both in vitro and in vivo experiments that made use of a pig's liver were conducted for comparison with the simulation using the model. Results of the in vitro experiment showed that the model reproduces nonlinear and viscoelastic response of displacement at an internally located point with high accuracy. For a force up to 0.45 N, the maximum error is below 1 mm. Results of the in vivo experiment showed that the model reproduces the nonlinear increase of load upon the needle during insertion. Based on these results, the liver model developed and validated in this work reproduces the physical response of a liver in both in vitro and in vivo situations. (orig.)
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Directory of Open Access Journals (Sweden)
Ewa Łukasiewicz
2017-12-01
Full Text Available Aim: The aim of the study was to review two techniques that can be used to verify focal lesions in the breasts: fine-needle aspiration biopsy and core-needle biopsy. Material and methods: Fifty-five articles (original papers and reviews, half of them published within the past 5 years, were included in the analysis. The authors also took their own experience into account. Results: Pre-operative assessment of focal lesions in the breasts is crucial in the planning of further therapeutic management. The role of fine-needle aspiration biopsy has been reduced lately due to its low sensitivity and specificity as well as a high rate of non-diagnostic, suspicious and false negative results. This method does not enable one to differentiate between in situ and invasive disease. Currently, fine-needle biopsy is recommended for cystic lesions, suspected of being recurrences in the chest wall, and lymph node metastases. Core-needle biopsy is the basic diagnostic method of breast lesions. According to the recommendations of the Polish Ultrasound Society and American College of Radiology, BIRADS 4 and 5 lesions should be evaluated histopathologically. Core-needle biopsy makes it possible to establish a final diagnosis more frequently than fine-needle biopsy, both in the case of benign and malignant lesions. It delivers more information about the nature of a tumor (mutation of HER-2, estrogen and progesterone receptors and Ki-67 index. Its limitations include: underestimation of invasion and failure to recognize the components of ductal carcinoma in situ in papillary and atypical lesions. Single fine-needle aspiration biopsy is inexpensive, but when considering the cost of further diagnosis due to non-diagnostic, suspicious and atypical results, this method generates high additional costs. Conclusions: Microscopic verification of focal breast lesions is crucial for further therapeutic decisions. It has been proven that histopathological verification is more
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Measurement of tritium in tissue free water of pine needles
International Nuclear Information System (INIS)
Zheng Xiaomin; Wu Zongmei
1993-01-01
Tissue Free Water (TFW) of pine needles is separated out through azeotropic distillation of pine needles and toluene. Recovery ratio of TFW is 90%. Tritium activity in the needles is 1.8 Bq/L(H 2 O), which is of the same level with tritiated water vapour (HTO) in atmosphere during the corresponding period
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Lee, Ban Seok; Cho, Chang-Min; Jung, Min Kyu; Jang, Jung Sik; Bae, Han Ik
2017-07-15
The superiority of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) over EUS-guided fine needle aspiration (EUS-FNA) remains controversial. Given the lack of studies analyzing histologic specimens acquired from EUS-FNB or EUS-FNA, we compared the proportion of the histologic core obtained from both techniques. A total of 58 consecutive patients with solid mass lesions were enrolled and randomly assigned to the EUS-FNA or EUS-FNB groups. The opposite needle was used after the failure of core tissue acquisition using the initial needle with up to three passes. Using computerized analyses of the scanned histologic slide, the overall area and the area of the histologic core portion in specimens obtained by the two techniques were compared. No significant differences were identified between the two groups with respect to demographic and clinical characteristics. Fewer needle passes were required to obtain core specimens in the FNB group (pcore (11.8%±19.5% vs 8.0%±11.1%, p=0.376) or in the diagnostic accuracy (80.6% vs 81.5%, p=0.935) between two groups. The proportion of histologic core and the diagnostic accuracy were comparable between the FNB and FNA groups. However, fewer needle passes were required to establish an accurate diagnosis in EUS-FNB.
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Dickenson, Nicholas E; Zhang, Lingling; Epler, Chelsea R; Adam, Philip R; Picking, Wendy L; Picking, William D
2011-01-18
Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming a tip complex that controls secretion. The bile salt deoxycholate (DOC) stimulates recruitment of the translocator protein IpaB into the maturing TTSA needle tip complex. This process appears to be triggered by a direct interaction between DOC and IpaD. Fluorescence spectroscopy and NMR spectroscopy are used here to confirm the DOC-IpaD interaction and to reveal that IpaD conformational changes upon DOC binding trigger the appearance of IpaB at the needle tip. Förster resonance energy transfer between specific sites on IpaD was used here to identify changes in distances between IpaD domains as a result of DOC binding. To further explore the effects of DOC binding on IpaD structure, NMR chemical shift mapping was employed. The environments of residues within the proposed DOC binding site and additional residues within the "distal" globular domain were perturbed upon DOC binding, further indicating that conformational changes occur within IpaD upon DOC binding. These events are proposed to be responsible for the recruitment of IpaB at the TTSA needle tip. Mutation analyses combined with additional spectroscopic analyses confirm that conformational changes in IpaD induced by DOC binding contribute to the recruitment of IpaB to the S. flexneri TTSA needle tip. These findings lay the foundation for determining how environmental factors promote TTSA needle tip maturation prior to host cell contact.
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Dickenson, Nicholas E.; Zhang, Lingling; Epler, Chelsea R.; Adam, Philip R.; Picking, Wendy L.; Picking, William D.
2011-01-01
Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming a tip complex that controls secretion. The bile salt deoxycholate (DOC) stimulates recruitment of the translocator protein IpaB into the maturing TTSA needle tip complex. This process appears to be triggered by a direct interaction between DOC and IpaD. Fluorescence spectroscopy and NMR spectroscopy are used here to confirm the DOC-IpaD interaction and to reveal that IpaD conformational changes upon DOC binding trigger the appearance of IpaB at the needle tip. Förster resonance energy transfer between specific sites on IpaD was used here to identify changes in distances between IpaD domains as a result of DOC binding. To further explore the effects of DOC binding on IpaD structure, NMR chemical shift mapping was employed. The environments of residues within the proposed DOC binding site and additional residues within the “distal” globular domain were perturbed upon DOC binding, further indicating that conformational changes occur within IpaD upon DOC binding. These events are proposed to be responsible for the recruitment of IpaB at the TTSA needle tip. Mutation analyses combined with additional spectroscopic analyses confirms that conformational changes in IpaD induced by DOC binding contribute to the recruitment of IpaB to the S. flexneri TTSA needle tip. These findings lay the foundation for determining how environmental factors promote TTSA needle tip maturation prior to host cell contact. PMID:21126091
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Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants
International Nuclear Information System (INIS)
Thompson, S.A.; Fung, A.Y.C.; Zaider, M.
2002-01-01
One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)
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Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants
Energy Technology Data Exchange (ETDEWEB)
Thompson, S.A. [Department of Medical Physics, North Shore-Long Island Jewish Health System, Manhassett, NY (United States); Fung, A.Y.C.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)
2002-08-21
One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)
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The Hydrodynamics of Needle-Free Intradermal Jet Injection
Simmons, Jonathan; Marston, Jeremy; Fisher, Paul; Broderick, Kate
2017-11-01
Needle-free methods of drug delivery circumvent the drawbacks associated with the use of hypodermic needles such as needle-stick injuries, needle-phobia, cross contamination and disposal. Furthermore, pioneering DNA-based vaccines that aim to treat cancer and fight infectious diseases, such as HIV, Ebola and Zika, require precise deposition into the skin to target the immune response producing cells found only in the epidermis and dermis. Intradermal (ID) delivery can be achieved using a needle and the Mantoux technique but this requires a highly skilled technician and so extensive use of DNA vaccines calls for an alternative method of delivery. One option is jet injection which has been employed in mass vaccination programs for intramuscular or subcutaneous delivery and is used by some diabetic patients to inject insulin. In this talk I will present results from our ongoing ex-vivo experimental study into ID jet injection. Ultra-high-speed imaging is used to visualize the process of the jet exiting the nozzle and striking excised skin. A skin bleb grows as liquid is deposited within the skin. I will discuss how the control parameters, such as the rheological profile of the liquid and the stand-off distance, influence the volume of liquid successfully delivered intradermally.
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Chen, Xingyang; Zhou, Chengshuang; Cai, Xiao; Zheng, Jinyang; Zhang, Lin
2017-10-01
The effects of external hydrogen on hydrogen transportation and distribution around the fatigue crack tip in type 304 stainless steel were investigated by using hydrogen microprint technique (HMT) and thermal desorption spectrometry. HMT results show that some silver particles induced by hydrogen release are located near the fatigue crack and more silver particles are concentrated around the crack tip, which indicates that hydrogen accumulates in the vicinity of the crack tip during the crack growth in hydrogen gas environment. Along with the crack propagation, strain-induced α' martensite forms around the crack tip and promotes hydrogen invasion into the matrix, which will cause the crack initiation and propagation at the austenite/ α' martensite interface. In addition, the hydrogen content in the vicinity of the crack tip is higher than that at the crack edge far away from the crack tip, which is related to the stress state and strain-induced α' martensite.
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Chemically etched fiber tips for near-field optical microscopy: a process for smoother tips.
Lambelet, P; Sayah, A; Pfeffer, M; Philipona, C; Marquis-Weible, F
1998-11-01
An improved method for producing fiber tips for scanning near-field optical microscopy is presented. The improvement consists of chemically etching quartz optical fibers through their acrylate jacket. This new method is compared with the previous one in which bare fibers were etched. With the new process the meniscus formed by the acid along the fiber does not move during etching, leading to a much smoother surface of the tip cone. Subsequent metallization is thus improved, resulting in better coverage of the tip with an aluminum opaque layer. Our results show that leakage can be avoided along the cone, and light transmission through the tip is spatially limited to an optical aperture of a 100-nm dimension.
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Single-incision laparoscopic cholecystectomy with needle graspers.
Sumiyoshi, Kinjiro; Sato, Norihiro; Akagawa, Shin; Hirano, Tatsuya; Koikawa, Kazuhiro; Horioka, Kohei; Ozono, Keigo; Fujiwara, Kenji; Tanaka, Masao; Sada, Masayuki
2012-01-01
Single-incision laparoscopic cholecystectomy (SILC) is a promising alternative to standard multi-incision laparoscopic cholecystectomy (LC). However, generalization of SILC is still hampered by technical difficulties mainly associated with the lack of trocars used for retraction of the gallbladder. We therefore developed a modified method of SILC with the use of needle graspers (SILC-N) for optimal retraction and exposure. In addition to two trocars inserted through a single transumbilical incision, two needle ports were placed on the right subcostal and lateral abdominal wall, through which needle graspers were used for retraction of the gallbladder. Since December, 2009, 12 patients with symptomatic cholelithiasis were treated by SILC-N. SILC-N was successfully performed in all but one patient requiring a conversion to the 4-port LC with a mean operative time of 71.5 (48-107) minutes. None of the patients experienced intraoperative or postoperative complications. The transumbilical incision and pinholes for needle graspers were almost invisible on discharge. Our preliminary results suggest that SILC-N is a simple, safe and feasible technique of cholecystectomy offering similar postoperative recovery and better cosmetic outcome as compared to conventional LC.
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Needle-shaped and platelet growth of borax crystals
International Nuclear Information System (INIS)
Takoo, R.K.; Patel, B.R.; Joshi, M.S.
1983-01-01
Needle-shaped and platelet growth of borax crystals from solutions is reported. Results of microtopographical studies on both the varieties are discussed. It is suggested that a slow rate of evaporation favours needle growth and a faster rate is conducive to the growth of platelets. (author)
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Discordance Rate between Thyroid Fine Needle Aspiration Cytology ...
African Journals Online (AJOL)
Discordance Rate between Thyroid Fine Needle Aspiration Cytology and Histopathologic Diagnosis. Wondwossen Ergete, Daniel Abebe. Abstract. Fine Needle Aspiration (FNA) of the thyroid is a low cost procedure, which can give an accurate diagnosis promptly. The objective of this study was to assess the diagnostic ...
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Biopsy Needle Localization and Tracking Using ROI-RK Method
Directory of Open Access Journals (Sweden)
Yue Zhao
2014-01-01
Full Text Available ROI-RK method is a biopsy needle localization and tracking method. Previous research work has proved that it has a robust performance on different series of simulated 3D US volumes. Unfortunately, in real situations, because of the strong speckle noise of the ultrasound image and the different echogenic properties of the tissues, the real 3D US volumes have more complex background than the simulated images used previously. In this paper, to adapt the ROI-RK method in real 3D US volumes, a line-filter enhancement calculation only in the ROI is added to increase the contrast between the needle and background tissue, decreasing the phenomenon of expansion of the biopsy needle due to reverberation of ultrasound in the needle. To make the ROI-RK method more stable, a self-correction system is also implemented. Real data have been acquired on an ex vivo heart of lamb. The result of the ROI-RK method shows that it is capable to localize and track the biopsy needle in real situations, and it satisfies the demand of real-time application.
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International Nuclear Information System (INIS)
Machado, C.N.; Maria, S.P.; Saiki, M.; Figueiredo, A.M.G.
1998-01-01
Instrumental neutron activation analysis was applied to determine La, Ce, Nd, Sm, Eu, Tb, Yb, Lu and Sc in two biological reference materials: NIST 1575 Pine Needles and BCR-CRM 101 Spruce Needles. The purpose was to contribute to the reference data for these two reference materials. The results were obtained with a good precision (relative standard deviations less than 15%). For the Pine Needles reference material there are already some proposed values and our results showed, in general, a good agreement with the data published. The contribution of uranium fission products to La, Ce, Nd and Sm was evaluated and considered in the determination of these elements. Interferences in the determination of rare earth elements in biological materials are also discussed. (author)
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Environmental Consequences of Nanotechnologies: Nanoparticle Dispersion in Aqueous Media: SOP-T-1
2015-02-01
to the particle dispersion) (<T>, <R>). 2. Insert clean pipette tip, syringe needle or Pasteur pipette with bulb and gently introduce mixing by...Insert clean pipette tip, syringe needle or Pasteur pipette with bulb and gently introduce mixing by slowly drawing up sample three times (<T>, <R
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... Staying Safe Videos for Educators Search English Español ADHD: Tips to Try KidsHealth / For Teens / ADHD: Tips to Try Print en español TDAH: Consejos que puedes probar ADHD , short for attention deficit hyperactivity disorder , is a ...
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Novel design of honeybee-inspired needles for percutaneous procedure.
Sahlabadi, Mohammad; Hutapea, Parsaoran
2018-04-18
The focus of this paper is to present new designs of innovative bioinspired needles to be used during percutaneous procedures. Insect stingers have been known to easily penetrate soft tissues. Bioinspired needles mimicking the barbs in a honeybee stinger were developed for a smaller insertion force, which can provide a less invasive procedure. Decreasing the insertion force will decrease the tissue deformation, which is essential for more accurate targeting. In this study, some design parameters, in particular, barb shape and geometry (i.e. front angle, back angle, and height) were defined, and their effects on the insertion force were investigated. Three-dimensional printing technology was used to manufacture bioinspired needles. A specially-designed insertion test setup using tissue mimicking polyvinyl chloride (PVC) gels was developed to measure the insertion and extraction forces. The barb design parameters were then experimentally modified through detailed experimental procedures to further reduce the insertion force. Different scales of the barbed needles were designed and used to explore the size-scale effect on the insertion force. To further investigate the efficacy of the proposed needle design in real surgeries, preliminary ex vivo insertion tests into bovine liver tissue were performed. Our results show that the insertion force of the needles in different scales decreased by 21-35% in PVC gel insertion tests, and by 46% in bovine liver tissue insertion tests.
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2015-07-01
maintained by the sympathetic branch of the autonomic nervous system as well as the somatic nervous system. Block- ade of the sympathetic nervous...through sternocleidomas- toid, continuing just ventral to the tip of the anterior tubercle of C6, then continuing on until the needle tip has just...know that questioning them is just another way to monitor how they are doing. It is absolutely critical to constantly keep the needle tip in view. If
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DEFF Research Database (Denmark)
Præstmark, Kezia Ann; Stallknecht, Bente Merete; Bo Jensen, Casper
2014-01-01
skin blood perfusion response around needle insertion sites. Three common sized pen needles of 28G, 30G, and 32G as well as hooked 32G needles, were inserted into the neck skin of pigs and then removed. Laser Speckle Contrast Analysis was used to measure skin blood perfusion for 20 minutes after...... blood perfusion recording and grouped according to needle type, skin blood perfusion response relates to needle diameter. The response was significantly higher after insertions with 28G and hooked 32G needles than with 30G (P ..., but there was a trend of an increased response with increasing needle diameter. Skin blood perfusion response to pen needle insertions rank according to needle diameter, and the tissue response caused by hooked 32G needles corresponds to that of 28G needles. The relation between needle diameter and trauma when...
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Thorn, Craig E.; Chasman, Chellis; Baltz, Anthony J.
1984-04-24
An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.
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Fine needle diagnosis in lumbar osteomyelitis
International Nuclear Information System (INIS)
Joshi, K.B.; Brinker, R.A.
1983-01-01
Lumbar vertebral body and disk infection, presenting as low back pain, is a relatively uncommon disease but is seen more often in drug addicts. Radiographs show typical changes of infection of the lumbar vertebrae and adjacent disc. Under local anesthesia a fine needle is placed, saline injected, and aspirated. The entire needle-syringe unit is submitted to the bacteriology department. Pseudomonas infection is usually found. This method of diagnosis is simple, cost effective, well accepted by the patients, and can be done on outpatients. (orig.)
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Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid
... Physician Resources Professions Site Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ... Aspiration Biopsy of the Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During ...
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Leaching of cell wall components caused by acid deposition on fir needles and trees
Energy Technology Data Exchange (ETDEWEB)
Shigihara, Ado [Department of Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686 (Japan)], E-mail: r200670202@kanagawa-u.ac.jp; Matsumoto, Kiyoshi [Department of Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686 (Japan); Sakurai, Naoki [Faculty of Integrated Arts and Science, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, 739-8521 (Japan); Igawa, Manabu [Department of Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686 (Japan)
2008-07-15
Virgin fir forests have been declining since the 1960s at Mt. Oyama, which is located at the eastern edge of the Tanzawa Mountains and adjacent to the Kanto plain in Japan. An acid fog frequently occurs in the mountains. We collected throughfall and stemflow under fir trees and rainfall every week during January-December 2004 at Mt. Oyama to clarify the influence of acid fog on the decline of fir (Abies firma) needles. In relation to throughfall and stemflow, D-mannose, D-galactose, and D-glucose are the major neutral sugar components; only D-glucose is a major component of rainfall. The correlation coefficient between the total neutral sugars and uronic acid (as D-galacturonic acid), which is a key component of the cross-linking between pectic polysaccharides, was high except for rainfall. The leached amount of calcium ion, neutral sugars, uronic acid, and boron is related to the nitrate ion concentration in throughfall. Results of a laboratory exposure experiment using artificial fog water simulating the average composition of fog water observed at Mt. Oyama (simulated acid fog: SAF) on the fir seedling needles also shows a large leaching of these components from the cell walls of fir needles. The leaching amount increased concomitantly with decreasing pH of the SAF solution. We also observed that a dimeric rhamnogalacturonan II-borate complex (dRG-II-B) that exists in the cell wall as pectic polysaccharide was converted to monomeric RG-II (mRG-II) by the leaching of calcium ion and boron. Results not only of field observations but also those of laboratory experiments indicate a large effect of acid depositions on fir needles.
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Al-Aamri, I; Derzi, S H; Moore, A; Elgueta, M F; Moustafa, M; Schricker, T; Tran, D Q
2017-07-01
Pressure waveform analysis provides a reliable confirmatory adjunct to the loss-of-resistance technique to identify the epidural space during thoracic epidural anaesthesia, but its role remains controversial in lumbar epidural analgesia during labour. We performed an observational study in 100 labouring women of the sensitivity and specificity of waveform analysis to determine the correct location of the epidural needle. After obtaining loss-of-resistance, the anaesthetist injected 5 ml saline through the epidural needle (accounting for the volume already used in the loss-of-resistance). Sterile extension tubing, connected to a pressure transducer, was attached to the needle. An investigator determined the presence or absence of a pulsatile waveform, synchronised with the heart rate, on a monitor screen that was not in the view of the anaesthetist or the parturient. A bolus of 4 ml lidocaine 2% with adrenaline 5 μg.ml -1 was administered, and the epidural block was assessed after 15 min. Three women displayed no sensory block at 15 min. The results showed: epidural block present, epidural waveform present 93; epidural block absent, epidural waveform absent 2; epidural block present, epidural waveform absent 4; epidural block absent, epidural waveform present 1. Compared with the use of a local anaesthetic bolus to ascertain the epidural space, the sensitivity, specificity, positive and negative predictive values of waveform analysis were 95.9%, 66.7%, 98.9% and 33.3%, respectively. Epidural waveform analysis provides a simple adjunct to loss-of-resistance for confirming needle placement during performance of obstetric epidurals, however, further studies are required before its routine implementation in clinical practice. © 2017 The Association of Anaesthetists of Great Britain and Ireland.
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Cronn, Richard; Dolan, Peter C.; Jogdeo, Sanjuro; Wegrzyn, Jill L.; Neale, David B.; St. Clair, J. Bradley; Denver, Dee R.
2017-01-01
Background Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) n...
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Effects of ozone exposures on epicuticular wax of ponderosa pine needles
International Nuclear Information System (INIS)
Bytnerowicz, A.; Turunen, M.
1994-01-01
Two-year-old ponderosa pine (Pinus ponderosa L.) seedlings were exposed during the 1989 and 1990 growing seasons to ozone in open-top chambers placed in a forested location at Shirley Meadow, Greenhorn Mountain Range, Sierra Nevada. The ozone treatments were as follows: charcoal-filtered air (CF); charcoal-filtered air with addition of ambient concentrations of ozone (CF + O 3 ); and charcoal-filtered air with addition of doubled concentrations of ozone (CF + 2 x O 3 ). Ozone effects on ponderosa pine seedlings progressed and accumulated over two seasons of exposure. Throughout the first season, increased visible injury and accelerated senescence of the foliage were noted. Subsequently, during the second season of ozone exposure, various physiological and biochemical changes in the foliage took place. All these changes led to reduced growth and biomass of the seedlings. Epistomatal waxes of needles from the CA + 2 x O 3 treatment had an occluded appearance. This phenomenon may be caused by earlier phenological development of needles from the high-ozone treatments and disturbed development and synthesis of waxes. It may also be caused by chemical degradation of waxes by exposures to high ozone concentrations. (orig.)
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International Nuclear Information System (INIS)
Lehtikangas, P.; Lundkvist, H.
1991-01-01
Part 1: Experimental piles were built in three geographical locations during May-Sept. 1989. Logging residues consisted of 95% spruce and 5% pine. Height of the piles varied between 80 and 230 cm. Needles were collected by placing drawers under 40 randomely chosen piles. The drawers were emptied every two weeks during the storage period. Natural needle loss was between 18 and 32% of the total amount of needles after the first two months of storage. At the end of the storage period, 24-42% of the needles had fallen down to the drawers. At the end of the experiment the total needle fall was 95-100% in the shaken piles. According to the results of this study piles smaller than 150 cm had the most effective needle fall. Piles should be placed on open places where the air and sun heat penetrate and dry them. Needles were the most sensitive fraction to variations in precipitation compared to the other components, such as branches. Piles usually dried quickly, but they also rewet easily. This was especially true in the smaller piles. The lowest moisture content was measured at the end of June. The ash content in needles varied between 4 and 8%. 16 refs., 15 figs. Part 2: Three field experiments were equipped with no-tension humus lysimeters. Pairs of lysimeters with the same humus/field layer vegetation material were placed in pairs, one under a pile of felling residues and another in the open clear felling. Leaching of nitrogen as well as pH and electric conductivity in the leachate was followed through sampling of the leachate at regular intervals. The results from the investigation show that: * the amount of leachate was higher in lysimeters in the open clear felling, * pH in the leachate was initially lower under piles of felling residues, * the amount of nitrogen leached was higher in the open clear felling. Thus, storing of felling residues in piles during the summer season did not cause any increase in nitrogen leaching, which had been considered to be a risk
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Tritium in pine needles and its significant sources in the environment
International Nuclear Information System (INIS)
Takashima, Y.; Momoshima, N.; Inoue, M.; Nakamura, Y.
1987-01-01
Tissue-free water tritium (TFWT) and tissue-bound tritium (TBT) were analyzed in pine needles collected at 21 locations of the general environment in Japan. The TFWT was recovered by freeze-drying and the TBT was obtained in the form of water by combustion of dried samples. Tritium was measured by liquid scintillation counting. The concentration of TFWT were comparable with those in natural waters in Japan. The concentration of TBT, however, was higher than that of TFWT. This excess TBT may be attributed to direct assimilation of HT that is present in the atmosphere with extremely high specific activity. (author)
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[Professor Feng Run-Shen's essential experience in penetration needling method].
Feng, Mu-Lan
2009-04-01
Professor Feng Run-Shen is engaged in medicine for more than 60 years. He pays attention to medical ethics and has perfect medical skill. He energetically advocates combination of acupuncture with medication and stresses the concept of viewing the situation as a whole in selection of acupoints and treatment, particularly, clinical application of point properties. Clinically, he is accomplished in penetration needling, for which one needle acts on two or more points, enlarging the range of needling sensation, so it has very good therapeutic effects on many diseases. In the paper, the case samples about penetration needling in his clinical practice are summarized and introduced.
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Fine Needle Aspiration Cytology In Tumour Diagnosis | Obaseki ...
African Journals Online (AJOL)
Fine needle aspiration cytology (FNAC), a technique for obtaining cellular material for cytological examination and diagnosis using a 21- gauge or smaller needle, is performed using a 5, 10, or 20ml syringe either freehand or using special syringe holders. It allows a minimally invasive, rapid diagnosis of tissue samples but
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International Nuclear Information System (INIS)
Qin Yongmei; Wang Laihao; Zhao Lihua; Guo Xiaogang; Kong Qingfeng
2009-01-01
Objective: To investigate the improvement of radionuclide bone imaging agent injection needle withdrawal method on whole body bone scan image quality. Methods: Elbow vein injection syringe needle directly into the bone imaging agent in the routine group of 117 cases, with a cotton swab needle injection method for the rapid pull out the needle puncture point pressing, pressing moment. Improvement of 117 cases of needle injection method to put two needles into the skin swabs and blood vessels, pull out the needle while pressing two or more entry point 5min. After 2 hours underwent whole body bone SPECT imaging plane. Results: The conventional group at the injection site imaging agents uptake rate was 16.24%, improved group was 2.56%. Conclusion: The modified bone imaging agent injection needle withdrawal method, injection-site imaging agent uptake were significantly decreased whole body bone imaging can improve image quality. (authors)
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Chami, H A; Faraj, W; Yehia, Z A; Badour, S A; Sawan, P; Rebeiz, K; Safa, R; Saade, C; Ghandour, B; Shamseddine, A; Mukherji, D; Haydar, A A
2015-12-01
To evaluate the association of quantitative computed tomography (CT) measures of emphysema with the occurrence of pneumothorax after CT-guided needle lung biopsy (NLB) accounting for other risk factors. One hundred and sixty-three CT-guided NLBs performed between 2008 and 2013 with available complete chest CT within 30 days were reviewed for the occurrence of post-procedure pneumothorax. Percent emphysema was determined quantitatively as the percentage of lung voxels below -950 HU on chest CT images using automated software. Multivariable regression was used to assess the association of percent emphysema volume with the occurrence of post-procedure pneumothorax. The association of percent emphysema volume with the pneumothorax size and need for chest tube placement after NLB was also explored. Percent emphysema was significantly associated with the incidence of post-NLB pneumothorax (OR=1.10 95% confidence interval: 1.01-1.15; p=0.03) adjusting for lower-lobe lesion location, needle path length, lesion size, number of passes, and pleural needle trajectory angle. Percent emphysema was not associated with the size of the pneumothorax, nor the need for chest tube placement after NLB. Percent emphysema determined quantitatively from chest CT is a significant predictor of post-NLB pneumothorax. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
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Needle-free influenza vaccination
Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Frijlink, Henderik W.; Wilschut, Jan C.; Huckriede, Anke
2010-01-01
Vaccination is the cornerstone of influenza control in epidemic and pandemic situations. Influenza vaccines are typically given by intramuscular injection. However, needle-free vaccinations could offer several distinct advantages over intramuscular injections: they are pain-free, easier to
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Numerical investigation of three wind turbine blade tips
Energy Technology Data Exchange (ETDEWEB)
Johansen, J.; Soerensen, N.N.
2002-08-01
The complex three-dimensional flow around three different tip shapes on a rotating wind turbine blade is investigated and analyzed using Computational Fluid Dynamics. Differences in production, flap wise bending moments and forces are discussed. A method for determining the local inflow angle of attack is presented and further analysis is performed on lift and drag coefficients. It is shown that the original Standard tip results in a more concentrated tip vortex leading to a steeper gradient on both tangential and normal forces when approaching the tip, whereas the two tapered tips show a more flat behavior. This again leads to lower flap wise bending moments and lower production for the Standard tip compared to the two tapered tips. At 12 m/s, though, the Swept tip shows a separation pattern on the surface. This separation causes a decrease in normal force and an increase in tangential force. The Taper tip keeps the higher loading causing the flap wise bending moment to be higher as seen in measurements. To determine the radial variation of lift and drag coefficients the local inflow angle of attack is determined. It is shown that the Standard tip experiences a slightly larger angle of attack at the tip compared to the two tapered tips. The lift coefficients are kept at a more constant level for the two tapered tips due to the decrease in chord, while the drag coefficients actually decrease for the two tapered tips, especially for the Swept tip. For the Swept tip at 12 m/s both lift and drag coefficients changed considerably due to the separation. Differences in aerodynamic damping of the three tips were investigated using HAWCDAMP. The Standard tip seems to be slightly less damped with respect to the edgewise vibrations. (au)
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Lightning Safety Tips and Resources
... Services Careers Contact Us Glossary Safety National Program Lightning Safety Tips and Resources Weather.gov > Safety > Lightning Safety Tips and Resources Lightning Resources Lightning strikes ...
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A study on applying Ra needle interstitial brachytherapy for oral cancer
International Nuclear Information System (INIS)
Yoshida, Shunichi; Komiya, Yoshiaki; Uchida, Ikuhiro; Tashiro, Kazuyoshi
1999-01-01
To investigate applicability of Ra needle interstitial brachytherapy, 93 cases of oral squamous carcinoma were examined. The patients underwent Ra needle interstitial brachytherapy as thorough therapy in our hospital. The criteria of applying Ra needle interstitial brachytherapy was diameter of within 5 cm and depth within 2 cm of tumor size. Ra needle interstitial brachytherapy was applied to 82 cases of tongue, 10 cases of oral floor and one case of lower lip carcinomas. The local control rate was 92.5%, and secondary neck metastasis was 32.3% in all cases applied Ra needle interstitial brachytherapy. The results were not bad compared with surgical treatment. However, the 5-year cumulative survival rate was 64.9%, which was not good enough at the result to obtain a good local control rate and secondary neck metastasis rate. The result was relative to low treatment result of local recurrence cases with Ra needle interstitial brachytherapy. To improve the result, it is important to distinguish local recurrence from radioinduced ulcer, and to start early secondary treatment. The cases in which cervical lymph node metastasis was found as the first examination underwent neck dessection after Ra needle interstitial brachytherapy. The 5-year cumulative survival rate was 83.3% in N1 cases and 40.6% in N2 cases, and the result of N2 cases was poorer than N1 cases with a significant difference. The results indicate that a needle having a diameter of within 5 cm, depth of within 2 cm and less than N1 can be applied during Ra needle interstitial brachytherapy for complete cure of cancer. (author)
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SU-D-213AB-06: Surface Texture and Insertion Speed Effect on Needle Friction.
Abdullah, A; Golecki, C; Barnett, A; Moore, J
2012-06-01
High frictional forces between the needle surface and tissue cause tissue deflection which hinders accurate needle placement for procedures such as brachytherapy and needle biopsy. Accurate needle placement isimportant to maximize procedure efficacy. This work investigates how needle surface roughness and insertion speed affect the frictional forcebetween a needle and tissue. A friction experiment was conducted to measure the force of friction between bovine liver and three 11 gauge needles having Ra surface roughness of 3.43, 1.33, and 0.2 μm. Each of the three needles were mounted on a linear slide and were advanced and retracted through bovine liver at speeds of 50, 100, 150, and 200 mm/s for a total of 12 trials. In each trial the needle was advanced and retracted in 10 cycles producing a steady state insertion force and a steady state retraction force for each cycle. A force sensor connecting the needle to the linear slide recorded the resistance force of the needle sliding through the liver. The liver was mounted in a box with a pneumatic cylinder which compressed the liver sample by 11.65 kPa. The roughest needle (Ra = 3.43 μm) on average produced 68, 73, 74, and 73% lower friction force than the smoothest needle (Ra = 0.2 μm) for the speeds of 50, 100, 150, and 200mm/s, respectively. The second roughest needle (Ra = 1.33 μm) on average produced 25, 45, 60 and 64% lower friction force than the smoothest needle (Ra = 0.2 μm) for the speeds of 50, 100, 150, and 200 mm/s, respectively. Rougher needle surface texture and higher insertion speed reduced frictional forces between the tissue and the needle. Future studies will examine how frictional forces can be modeled and predicted given surface texture and insertion speed. © 2012 American Association of Physicists in Medicine.
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M.G. Dallinga (Marchien); S.E.M. Boas (Sonja); I. Klaassen (Ingeborg); R.M.H. Merks (Roeland); C.J.F. van Noorden; R.O. Schlingemann (Reinier)
2015-01-01
htmlabstractIn angiogenesis, the process in which blood vessel sprouts grow out from a pre-existing vascular network, the so-called endothelial tip cells play an essential role. Tip cells are the leading cells of the sprouts; they guide following endothelial cells and sense their environment for
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International Nuclear Information System (INIS)
Goennenwein, F.; Boersig, B.
1991-01-01
Cold fission is defined to be the limiting case of nuclear fission where virtually all of the available energy is converted into the total kinetic energy of the fragments. The fragments have, therefore, to be born in or at least close to their respective ground states. Starting from the viewpoint that cold fission corresponds to most compact scission configurations, energy constraints have been exploited to calculate minimum tip distances between the two nascent fragments in binary fission. Crucial input parameters to this tip model of cold fission are the ground-state deformations of fragment nuclei. It is shown that the minimum tip distances being compatible with energy conservation vary strongly with both the mass and charge fragmentation of the fission prone nucleus. The tip distances refer to nuclei with equivalent sharp surfaces. In keeping with the size of the surface width of leptodermous nuclei, only configurations where the tip distances are smaller than a few fm may be considered as valid scission configurations. From a comparison with experimental data on cold fission this critical tip distance appears to be 3.0 fm for the model parameters chosen. Whenever the model calculation yields tip distances being smaller than the critical value, a necessary condition for attaining cold fission is considered to be fulfilled. It is shown that this criterion allows to understand in fair agreement with experiment which mass fragmentations are susceptible to lead to cold fission and which fragment-charge divisions are the most favored in each isobaric mass chain. Being based merely on energy arguments, the model cannot aim at predicting fragment yields in cold fission. However, the tip model proposed appears well suited to delineate the phase space where cold fission phenomena may come into sight. (orig.)
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Students as effective harm reductionists and needle exchange organizers.
Barbour, Kyle; McQuade, Miriam; Brown, Brandon
2017-03-17
Needle exchange programs are safe, highly effective programs for promoting health among people who inject drugs. However, they remain poorly funded, and often illegal, in many places worldwide due to fear and stigma surrounding drug use. Continued advocacy, education, and implementation of new needle exchanges are thus essential to improve public health and reduce structural inequality. We argue that students, and especially professional and graduate students, have the potential to play an important role in advancing harm reduction. Students benefit from the respect given to the professions they are training to enter, which gives them leverage to navigate the political hurdles often faced by needle exchange organizers, especially in areas that presently lack services. In addition, due to their relative simplicity, needle exchanges do not require much of the licensing, clinical knowledge, and infrastructure associated with more traditional student programs, such as student-run free medical clinics. Students are capable of learning harm reduction cultural approaches and techniques if they remain humble, open-minded, and seek the help of the harm reduction community. Consequently, students can generate tremendous benefits to their community without performing beyond their appropriate clinical limitations. Students benefit from organizing needle exchanges by gaining applied experience in advocacy, organization-building, and political finesse. Working in a needle exchange significantly helps erode stigma against multiple marginalized populations. Students in health-related professions additionally learn clinically-relevant knowledge that is often lacking from their formal training, such as an understanding of structural violence and inequality, root causes of substance use, client-centered approaches to health services, and interacting with clients as peers, rather than through the standard hierarchical medical interaction. We therefore encourage students to learn about
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In vivo motion and force measurement of surgical needle intervention during prostate brachytherapy
International Nuclear Information System (INIS)
Podder, Tarun; Clark, Douglas; Sherman, Jason; Fuller, Dave; Messing, Edward; Rubens, Deborah; Strang, John; Brasacchio, Ralph; Liao, Lydia; Ng, W.-S.; Yu Yan
2006-01-01
In this paper, we present needle insertion forces and motion trajectories measured during actual brachytherapy needle insertion while implanting radioactive seeds in the prostate glands of 20 different patients. The needle motion was captured using ultrasound images and a 6 degree-of-freedom electromagnetic-based position sensor. Needle velocity was computed from the position information and the corresponding time stamps. From in vivo data we found the maximum needle insertion forces to be about 15.6 and 8.9 N for 17 gauge (1.47 mm) and 18 gauge (1.27 mm) needles, respectively. Part of this difference in insertion forces is due to the needle size difference (17G and 18G) and the other part is due to the difference in tissue properties that are specific to the individual patient. Some transverse forces were observed, which are attributed to several factors such as tissue heterogeneity, organ movement, human factors in surgery, and the interaction between the template and the needle. However, theses insertion forces are significantly responsible for needle deviation from the desired trajectory and target movement. Therefore, a proper selection of needle and modulated velocity (translational and rotational) may reduce the tissue deformation and target movement by reducing insertion forces and thereby improve the seed delivery accuracy. The knowledge gleaned from this study promises to be useful for not only designing mechanical/robotic systems but also developing a predictive deformation model of the prostate and real-time adaptive controlling of the needle
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Directory of Open Access Journals (Sweden)
Adam LLOYD
Full Text Available ABSTRACT Objective This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS, passive ultrasonic irrigation (PUI with EndoUltra and standard needle irrigation (SNI in the removal of calcium hydroxide [Ca(OH2] from the mesial roots of Weine Type II mandibular molars. Material and Methods Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH2 paste. Specimens were divided into three groups (n=10 according to the technique used for Ca(OH2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle. Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH2 present and to assess the residual volume of Ca(OH2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%. Results The mean volume of Ca(OH2 before removal was significantly higher in the coronal third than in the middle and apical third (p0.05. PIPS (median 0%; IQR: 0-0 showed significant higher Ca(OH2 removal in the apical third than PUI (median 100%, IQR: 85-100 and SNI (median 47%; IQR: 16-72 (p<0.001. Conclusions PIPS laser-activation was more effective for the removal of Ca(OH2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.
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[Treatment of Persistent Somatoform Pain Disorder by Floating Needle Therapy and Duloxetine].
Ren, Wan-wen; Zhou, Zhi-ying; Xu, Mi-mi; Long, Sen; Tang, Guang-zheng; Mao, Hong-jing; Chen, Shu-lin
2016-02-01
To evaluate clinical effect and safety of floating needle therapy and duloxetine in treating patients with persistent somatoform pain disorder (PSPD). Totally 108 PSPD patients were randomly assigned to the floating needle treatment group, the duloxetine treatment group, and the placebo treatment group, 36 in each group. Patients in the floating needle treatment group received floating needle therapy and placebo. Those in the duloxetine treatment group received duloxetine and simulated floating needle therapy. Those in the placebo treatment group received the placebo and simulated floating needle therapy. All treatment lasted for six weeks. Efficacy and adverse reactions were evaluated using Simple McGill pain scale (SF-MPQ) and Treatment Emergent Symptom Scale (TESS) before treatment and immediately after treatment, as well as at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Hamilton Depression Scale (HAMD, 17 items), Hamilton Anxiety Scale (HAMA) were assessed before treatment and at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Patients in the floating needle treatment group and the duloxetine treatment group with the total reducing score rate of SF-MPQ in Pain Rating index (PRI) ≥ 50% after 6 weeks' treatment were involved in the follow-up study. (1) Compared with the same group before treatment, SF-MPQ score, HAMD score and HAMA total scores all decreased in all the three groups at the end of 1st, 2nd, 4th, and 6th week of treatment (P floating needle treatment group (P floating needle treatment group significantly decreased after 1, 2, 4, and 6 weeks of treatment (P floating needle treatment group, 17 (50.0%) in the duloxetine treatment group, and 7 (21.2%) in the placebo treatment group. Compared with the placebo treatment group, the incidence of adverse reaction increased in the duloxetine treatment group (χ² = 6.04, P floating needle treatment group (χ² = 14.9, P floating needle treatment group and 17
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NEEDLE KNIFE SPHINCTEROTOMY - THE CHRIS HANI BARAGWANATH ACADEMIC HOSPITAL EXPERIENCE.
Thomson, J T; Smith, M D; Omoshoro-Jones, J A O; Devar, J D; Khan, Z K; Jugmohan, B J
2017-06-01
Deep biliary cannulation is essential in performing a therapeutic ERCP. Cannulation can be enhanced through the utilization of a pre-cut by means of a needle knife sphincterotomy. Retrospective analysis of the Chris Hani Baragwanath Academic Hospital's ERCP database was performed. All ERCPs performed with the aid of a needle knife were identified and analysed for successful and unsuccessful deep biliary cannulation. 2830 ERCPs were performed during the study period. 369 (13%) required needle knife sphincterotomies and successful deep biliary cannulation was achieved in 229 (62%) of these patients. Repeat ERCPs were performed on 125 (34%) patients. 61 (49%) of the repeat ERCPs were performed because of previously failed cannulation. 34 (56%) of these repeat ERCPs resulted in successful deep biliary cannulation at re-attempt. 99% of successful cannulations at repeat ERCP had had a needle knife sphincterotomy at the first ERCP. Needle knife sphincterotomy improves deep biliary cannulation at initial ERCP and subsequent ERCPs with low incidences of complications.
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Acupuncture sensation during ultrasound guided acupuncture needling
Park, Jongbae J.; Akazawa, Margeaux; Ahn, Jaeki; Beckman-Harned, Selena; Lin, Feng-Chang; Lee, Kwangjae; Fine, Jason; Davis, Robert T; Langevin, Helene
2014-01-01
Background Although acupuncture sensation (also known as de qi) is a cornerstone of traditional acupuncture therapy, most research has accepted the traditional method of defining acupuncture sensation only through subjective patient reports rather than on any quantifiable physiological basis. Purpose To preliminarily investigate the frequency of key sensations experienced while needling to specific, quantifiable tissue levels (TLs) guided by ultrasound (US) imaging. Methods Five participants received needling at two acupuncture points and two control points at four TLs. US scans were used to determine when each TL was reached. Each volunteer completed 32 sets of modified Southampton Needle Sensation Questionnaires. Part one of the study tested sensations experienced at each TL and part two compared the effect of oscillation alone versus oscillation + rotation. Results In all volunteers, the frequency of pricking, sharp sensations was significantly greater in shallower TLs than deeper (p=0.007); the frequency of sensations described as deep, dull and heavy, as spreading, and as electric shocks was significantly greater in deeper TLs than shallower (p=0.002). Sensations experienced did not significantly differ between real and control points within each of three TLs (p>0.05) except TL 4 (p=0.006). The introduction of needle rotation significantly increased deep, dull, heavy sensations, but not pricking and sharp sensations; within each level, the spectrum of sensation experienced during both oscillation + rotation and oscillation alone did not significantly differ between acupuncture and control points. Conclusion The preliminary study indicates a strong connection between acupuncture sensation and both tissue depth and needle rotation. Furthermore, the new methodology has been proven feasible. A further study with an objective measurement is warranted. PMID:21642648
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Early warning of climate tipping points
Lenton, Timothy M.
2011-07-01
A climate 'tipping point' occurs when a small change in forcing triggers a strongly nonlinear response in the internal dynamics of part of the climate system, qualitatively changing its future state. Human-induced climate change could push several large-scale 'tipping elements' past a tipping point. Candidates include irreversible melt of the Greenland ice sheet, dieback of the Amazon rainforest and shift of the West African monsoon. Recent assessments give an increased probability of future tipping events, and the corresponding impacts are estimated to be large, making them significant risks. Recent work shows that early warning of an approaching climate tipping point is possible in principle, and could have considerable value in reducing the risk that they pose.
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Dolan, Peter; Cronn, Richard; Denver, Dee; Clair, J.; Neale, David; Wegrzyn, Jill; Jogdeo, Sanjuro
2017-01-01
Background: Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal rhythms and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii)...
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Biocompatible 3D printed magnetic micro needles
Kavaldzhiev, Mincho
2017-01-30
Biocompatible functional materials play a significant role in drug delivery, tissue engineering and single cell analysis. We utilized 3D printing to produce high aspect ratio polymer resist microneedles on a silicon substrate and functionalized them by iron coating. Two-photon polymerization lithography has been used for printing cylindrical, pyramidal, and conical needles from a drop cast IP-DIP resist. Experiments with cells were conducted with cylindrical microneedles with 630 ± 15 nm in diameter with an aspect ratio of 1:10 and pitch of 12 μm. The needles have been arranged in square shaped arrays with various dimensions. The iron coating of the needles was 120 ± 15 nm thick and has isotropic magnetic behavior. The chemical composition and oxidation state were determined using energy electron loss spectroscopy, revealing a mixture of iron and Fe3O4 clusters. A biocompatibility assessment was performed through fluorescence microscopy using calcein/EthD-1 live/dead assay. The results show a very high biocompatibility of the iron coated needle arrays. This study provides a strategy to obtain electromagnetically functional microneedles that benefit from the flexibility in terms of geometry and shape of 3D printing. Potential applications are in areas like tissue engineering, single cell analysis or drug delivery.
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Biocompatible 3D printed magnetic micro needles
Kavaldzhiev, Mincho; Perez, Jose E.; Ivanov, Yurii; Bertoncini, Andrea; Liberale, Carlo; Kosel, Jü rgen
2017-01-01
Biocompatible functional materials play a significant role in drug delivery, tissue engineering and single cell analysis. We utilized 3D printing to produce high aspect ratio polymer resist microneedles on a silicon substrate and functionalized them by iron coating. Two-photon polymerization lithography has been used for printing cylindrical, pyramidal, and conical needles from a drop cast IP-DIP resist. Experiments with cells were conducted with cylindrical microneedles with 630 ± 15 nm in diameter with an aspect ratio of 1:10 and pitch of 12 μm. The needles have been arranged in square shaped arrays with various dimensions. The iron coating of the needles was 120 ± 15 nm thick and has isotropic magnetic behavior. The chemical composition and oxidation state were determined using energy electron loss spectroscopy, revealing a mixture of iron and Fe3O4 clusters. A biocompatibility assessment was performed through fluorescence microscopy using calcein/EthD-1 live/dead assay. The results show a very high biocompatibility of the iron coated needle arrays. This study provides a strategy to obtain electromagnetically functional microneedles that benefit from the flexibility in terms of geometry and shape of 3D printing. Potential applications are in areas like tissue engineering, single cell analysis or drug delivery.
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[Closed needle-biopsy in the diagnosis of neoplasms].
Sforza, M; Perelli Ercolini, M; Beani, G
1979-04-01
The AA. demonstrate with this communication the validity of the needle biopsie for the diagnosis of neoplasms. They had used it for the breast, thyroid, flg and some other superficial tumefactions. In the mass-screening for the feminine neoplasms the clinical examination and the needle biopsy are very good method for a careful diagnosis.
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AFM tip-sample convolution effects for cylinder protrusions
Shen, Jian; Zhang, Dan; Zhang, Fei-Hu; Gan, Yang
2017-11-01
A thorough understanding about the AFM tip geometry dependent artifacts and tip-sample convolution effect is essential for reliable AFM topographic characterization and dimensional metrology. Using rigid sapphire cylinder protrusions (diameter: 2.25 μm, height: 575 nm) as the model system, a systematic and quantitative study about the imaging artifacts of four types of tips-two different pyramidal tips, one tetrahedral tip and one super sharp whisker tip-is carried out through comparing tip geometry dependent variations in AFM topography of cylinders and constructing the rigid tip-cylinder convolution models. We found that the imaging artifacts and the tip-sample convolution effect are critically related to the actual inclination of the working cantilever, the tip geometry, and the obstructive contacts between the working tip's planes/edges and the cylinder. Artifact-free images can only be obtained provided that all planes and edges of the working tip are steeper than the cylinder sidewalls. The findings reported here will contribute to reliable AFM characterization of surface features of micron or hundreds of nanometers in height that are frequently met in semiconductor, biology and materials fields.
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Automated location detection of injection site for preclinical stereotactic neurosurgery procedure
Abbaszadeh, Shiva; Wu, Hemmings C. H.
2017-03-01
Currently, during stereotactic neurosurgery procedures, the manual task of locating the proper area for needle insertion or implantation of electrode/cannula/optic fiber can be time consuming. The requirement of the task is to quickly and accurately find the location for insertion. In this study we investigate an automated method to locate the entry point of region of interest. This method leverages a digital image capture system, pattern recognition, and motorized stages. Template matching of known anatomical identifiable regions is used to find regions of interest (e.g. Bregma) in rodents. For our initial study, we tackle the problem of automatically detecting the entry point.
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Huang, Chih-Hao; Tanaka, Takahiro; Takaoki, Yutaka; Izumi, Hayato; Takahashi, Tomokazu; Suzuki, Masato; Aoyagi, Seiji
Aiming at the use in low-invasive medical treatments, this paper reports a fabrication of metallic microneedle, which has a three-dimensionally sharp tip. Compared to a silicon or polymer needle which we previously proposed, a metallic needle has toughness to evade breakage. Even if it is broken, it does not become small pieces thanks to its ductility, which increases the safety for a human body. A nickel needle was fabricated using electroplating, followed by sharpening it by electrochemical etching. A smooth tip surface is obtained due to electrochemical etching reactions. Sharpness and smoothness of the tip are effective for easy insertion in the viewpoint of large stress concentration and small friction, respectively. An experiment of inserting the fabricated needle into an artificial skin of silicone rubber was carried out. The resistance force during insertion was much reduced compared to that of commercial stainless needle (23 G: shank diameter 650 µm). Although a fabricated metallic needle was inserted and pulled-out for several times, it was not broken in any trial. By changing the angle between object surface and needle axis, the insertion experiments were carried out. Fabricated nickel needle was not broken for any angle, while silicon needle was broken in case the angle is small, i.e., the needle is much inclined from normal direction of the surface, which ensures the safety of metallic microneedle to human body in the viewpoint of breakage.
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Energy Technology Data Exchange (ETDEWEB)
Gogolek, P. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre
2004-07-01
This paper discusses the testing procedures and development of an improved flare tip design. Design objectives included performance equal to or better than utility flares at low wind speed; conversion efficiency; fuel slip; smoking; significant improvement at high wind speed; and no increase in trace emissions. A description of the testing facility of the flare tip was provided, with reference to the fact that the facility allowed for realistic near full scale gas flares in a single-pass flare test facility. Other details of the facility included: an adjustable ceiling; high capacity variable speed fan; sampling ports along working section in stack; windows along working section; and air cooled walls, floor, and ceiling. The fuels used in the flare tip included natural gas, propane, gasoline and inert gases. Details of wind speed, appurtenances and turbulence generating grids were presented, with reference to continuous gas emission measurements. A list of design constraints was provided. Flare performance included wind speed, turbulence and fuel composition. A chart of conversion inefficiencies with a correlation of wind speed and turbulence, fuel flow and pipe size was also presented. Several new tip designs were fabricated for testing, with screening tests for comparison to basic pipe and ranking designs. Significant improvements were found in one of the new designs, including results with 30 per cent propane in fuel. Emissions reduction from 10 to 35 per cent were noted. It was concluded that future work should focus on evaluating improved tip for stability at low wind speeds. Fuel slips are the primary source of emissions, and it was recommended that further research is necessary to improve existing flare tips. tabs, figs.
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The dynamics of spiral tip adjacent to inhomogeneity in cardiac tissue
Zhang, Juan; Tang, Jun; Ma, Jun; Luo, Jin Ming; Yang, Xian Qing
2018-02-01
Rotating spiral waves in cardiac tissue are implicated in life threatening cardiac arrhythmias. Experimental and theoretical evidences suggest the inhomogeneities in cardiac tissue play a significant role in the dynamics of spiral waves. Based on a modified 2D cardiac tissue model, the interaction of inhomogeneity on the nearby rigidly rotating spiral wave is numerically studied. The adjacent area of the inhomogeneity is divided to two areas, when the initial rotating center of the spiral tip is located in the two areas, the spiral tip will be attracted and anchor on the inhomogeneity finally, or be repulsed away. The width of the area is significantly dependent on the intensity and size of the inhomogeneity. Our numerical study sheds some light on the mechanism of the interaction of inhomogeneity on the spiral wave in cardiac tissue.
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Options for reducing HIV transmission related to the dead space in needles and syringes.
Zule, William A; Pande, Poonam G; Otiashvili, David; Bobashev, Georgiy V; Friedman, Samuel R; Gyarmathy, V Anna; Des Jarlais, Don C
2018-01-15
When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently. We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing. Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles. The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.
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International Nuclear Information System (INIS)
Ho, C.S.; Kachura, J.R.; Gallinger, S.; Grant, D.; Greig, P.; McGilvray, I.; Knox, J.; Sherman, M.; Wong, F.; Wong, D.
2007-01-01
Fine needles with an end hole or multiple side holes have traditionally been used for percutaneous ethanol injection (PEI) of hepatomas. This study retrospectively evaluates the safety and efficacy of PEI of unresectable medium-to-large (3.5-9 cm) hepatomas using a multipronged needle and with conscious sedation. Twelve patients, eight men and four women (age 51-77 years; mean: 69) received PEI for hepatomas, mostly subcapsular or exophytic in location with average tumor size of 5.6 cm (range: 3.5-9.0 cm). Patients were consciously sedated and an 18G retractable multipronged needle (Quadrafuse needle; Rex Medical, Philadelphia, PA) was used for injection under real-time ultrasound guidance. By varying the length of the prongs and rotating the needle, the alcohol was widely distributed within the tumor. The progress of ablation was monitored by contrast-enhanced ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) after each weekly injection and within a month after the final (third) injection and 3 months thereafter. An average total of 63 mL (range: 20-154 ml) of alcohol was injected per patient in an average of 2.3 sessions. Contrast-enhanced CT, ultrasound, or MRI was used to determine the degree of necrosis. Complete necrosis was noted in eight patients (67%), near-complete necrosis (90-99%) in two (16.7%), and partial success (50-89%) in two (16.7%). Follow-up in the first 9 months showed local recurrence in two patients and new lesions in another. There was no mortality. One patient developed renal failure, liver failure, and localized perforation of the stomach. He responded to medical treatment and surgery was not required for the perforation. One patient had severe postprocedural abdominal pain and fever, and another had transient hyperbilirubinemia; both recovered with conservative treatment. PEI with a multipronged needle is a new, safe, and efficacious method in treating medium-to-large-sized hepatocellular carcinoma under conscious
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Mind the gap - tip leakage vortex in axial turbines
International Nuclear Information System (INIS)
Dreyer, M; Farhat, M; Decaix, J; Münch-Alligné, C
2014-01-01
The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex
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Mind the gap - tip leakage vortex in axial turbines
Dreyer, M.; Decaix, J.; Münch-Alligné, C.; Farhat, M.
2014-03-01
The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex.
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NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants
Thompson, S. A.; Fung, A. Y. C.; Zaider, M.
2002-08-01
One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.
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Willemsen, O.H.; Kuipers, L.; van der Werf, Kees; de Grooth, B.G.; Greve, Jan
2000-01-01
The thermal movement of an atomic force microscope (AFM) tip is used to reconstruct the tip-surface interaction potential. If a tip is brought into the vicinity of a surface, its movement is governed by the sum of the harmonic cantilever potential and the tip-surface interaction potential. By
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Calibration of magnetic force microscopy tips by using nanoscale current-carrying parallel wires
International Nuclear Information System (INIS)
Kebe, Th.; Carl, A.
2004-01-01
Experimental results on the characterization of commercially available magnetic force microscopy (MFM) thin film tips as a function of an external magnetic field are presented. Magnetic stray fields with a definitive z-component (perpendicular to the substrate) and a magnetic field strength of up to H z =±45 Oe are produced with current carrying parallel nanowires with a thickness of t=60 nm, which are fabricated by electron-beam lithography. The magnetic fields are generated by electrical dc-currents of up to ±6 mA which are directed antiparallel through the nanowires. The geometry and the dimensions of the nanowires are systematically varied by choosing different wire widths w as well as separations b between the parallel wires for two different sets of samples. On the one hand, the wire width w is varied within 380 nm< w<2460 nm while the separation b≅450 nm between the wires is kept constant. On the other hand the separation b between the parallel wires is varied within 120 nm< b<5100 nm, while the wire width w=960 nm is kept constant. For all the geometrical configurations of parallel wires the resulting magnetic contrast is imaged by MFM at various tip lift-heights. By treating the MFM tip as a point probe, the analysis of the image contrast as a function of both the magnetic field strength and the tip lift height allows one to quantitatively determine the effective magnetic dipole and monopole moments of the tip as well as their imaginary locations within the real physical tip. Our systematic study quantitatively relates the above point-probe parameters to (i) the dimensions of the parallel wires and (ii) to the characteristic decay length of the z-component of the magnetic field of parallel wires. From this the effective tip-volume of the real thin film tip is determined which is relevant in MFM-imaging. Our results confirm the reliability of earlier tip calibration schemes for which nanofabricated current carrying rings were used instead of parallel
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International Nuclear Information System (INIS)
Beak, Jin Wook; KIm, Dong Wook; Kim, Bo Mi
2011-01-01
To assess the difference in the cytological adequacy of ultrasonography (US)-guided fine needle aspiration cytology (US-FNAC) for cervical lymphadenopathy using 21 and 23 gauge needles. US-FNACs were separately performed on two cervical lymph nodes and in each patient using 21 gauge (group A) and 23 gauge (group B) needles, respectively. We used 4 grade classifications for the cytological analysis of each slide and compared the cytological adequacy of US-FNAC for cervical lymphadenopathy in the two groups. We performed US-FNACs on 58 cervical lymph nodes from 29 patients, with a cytological adequacy of 69.0%. The number of adequate cytological results was 19 (65.5%) in group A and 21 (72.4%) in group B, and the diagnostic adequacy did not differ significantly between the two groups (Mann-Whitney test, p = 0.574). There was no statistically significant difference in the cytological adequacy of US-FNAC for cervical lymphadenopathy according using of 21 and 23 gauge needles.
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International Nuclear Information System (INIS)
Kim, Keon Woo; Kang, Duk Sik
1998-01-01
The purpose of this study is to compare the efficacy and safety of CT-guided automated gun biopsy with those of fine needle aspiration biopsy of pulmonary lesions. Under CT guidance, we performed automated gu biopsies in 115 cases of 109 patients and fine needle aspiration biopsies in 119 cases of 108 patients with pulmonary lesions. Between the two methods, we compared the diagnostic rate, diagnostic accuracy and frequency of compilations according to the depth and diameter of pulmonary lesions. The overall diagnostic rates of automated gun biopsy and fine needle aspiration biopsy were 76.5 % (88/115) and 64.7 % (77/119) respectively. There was a significant statistical difference (p=0.048), especially in the case of malignant lesions less than 3 cm (p=0.027) and more than 6 cm in maximal diameter (p=0.008), and in the lesions located from 1 cm to less than 3 cm from the pleural (p=0.030), as seen on CT. There was no significant statistical difference in the frequency of complications. Automated gun biopsy of pulmonary lesions under CT guidance is safe, with complications rate comparable to those of fine needle aspiration biopsy. A higher overall diagnostic rate can be achieved by automated gun biopsy than by fine needle aspiration biopsy. For the diagnosis of pulmonary lesions under CT guidance, automated gun biopsy is therefore a more useful procedure than fine needle aspiration biopsy. (author). 24 refs., 3 tabs
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Yang, Yang; Qi, Si; Liu, Mengyue; Zhao, Yu; Li, Ning
2017-10-12
To compare the differences in the clinical therapeutic effects on chronic knee joint pain between the combination of the central-square needling technique of thumb-tack needles with the routine therapy of acupuncture, moxibustion and tuina and the routine therapy of acupuncture, moxibustion and tuina . One hundred and twenty patients of chronic knee joint pain were randomized into an observation group and a control group, 60 cases in each one. In the control group, the routine therapy of acupuncture, moxibustion and tuina was adopted. In the observation group, at the end of treatment with the routine therapy of acupuncture, moxibustion and tuina , the subcutaneous embedding therapy was followed with four thumb-tack needles at the sites 1 to 1.5 cm above, below and bilateral to the main point ( ashi point) separately, and the needles were retained for 24 h to 48 h. The treatment was given once every two days, three times a week, totally 6 times in two weeks; and the follow-up visit was done for 3 months in patients of the two groups. The visual analogue scale (VAS) score before and after each treatment, Lequesne index score before treatment and at the end of follow-up and the case numbers of proactive use of painkillers or receiving acupuncture treatment in the follow-up stage were compared and observed in the patients of the two groups. The VAS score was reduced gradually after treatment in the patients of the two groups. The differences were significant statistically after the second treatment as compared with those before the treatment in the two groups (all P 0.05). In the follow-up stage, there were 0 case in the observation group and 9 cases in the control group in terms of proactive use of painkillers ( P 0.05). The acupuncture scheme in assistance with the central-square needling technique of thumb-tack needles obviously relieves chronic knee joint pain, much better sustains the analgesic effects of acupuncture and improves patient compliance.
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MR-guided MR arthrography of the shoulder
International Nuclear Information System (INIS)
Tratting, S.; Breitenseher, M.; Pretterklieber, M.; Kontaxis, G.; Rand, T.; Imhof, H.
1996-01-01
Purpose: To develop an MR-guided technique for joint puncture in MR arthrography of the shoulder and to confirm the intracapsular position of the needle tip by visualization of the flow of contrast media into the joint. Materials and methods: Three unfixed human shoulder joint specimens were examined on a 1.0 T unit. The optimal point of entrance and depth for joint puncture were estimated by means of MR-compatible markers on the skin. Needle orientation and localization of the needle tip (MR-compatible 22-gauge needle) in the shoulder joint were monitored by rapid localizer gradient-echo sequences in two orthogonal planes. To confirm the intracapsular position of the needle tip, diluted gadolinium-DTPA was administered via a long connecting tube and the flow of contrast media into the joint was viewed directly on an LCD screen using real-time MR imaging (local look technique). Results: The MR-compatible markers on the skin allowed determination of the optimal point of entrance and estimation of the depth for joint puncture. Passive visualization of the MR-compatible needle due to spin dephasing and signal loss provided adequate localization of the intra-articular needle tip position in all specimens, although significant artefacts were present on rapid localizer gradient-echo sequences with an increase in width of the apparent needle shaft. Real-time MR imaging of the flow of contrast media was possible using the local look technique and the LCD screen of the MR unit and allowed confirmation of the intracapsular position. Conclusion: MR-guided joint puncture and real-time MR-assisted contrast media application results in improved MR arthrography and may replace conventional fluoroscopic guidance. (orig.) [de
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Textiles: Some technocal information and data IV: sewability, sewing needles, threads and seams.
CSIR Research Space (South Africa)
Hunter, L
1979-09-01
Full Text Available half in about four c~ro"dd5 - - - - . . - - . Reducing the needle \\docity during its contact with the fabric can reduce needle temocratures bv about 50°C although other workers found the differences ;o be only 5 to IPC14. ~adiation plays a minor..., may have led to the confusion concerning the relative merits of different needle point30. Needle point shape does not appear to significantly affect maximum penetration force or energy~ expended while bulged-eye needles reduce heat build...
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DEFF Research Database (Denmark)
Mortensen, M B; Durup, J; Pless, T
2001-01-01
BACKGROUND AND STUDY AIMS: Laparoscopic ultrasonography (LUS) is an important imaging modality during laparoscopic staging of intra-abdominal malignancies, but LUS-assisted biopsy is often difficult or impossible. We report a newly developed inbuilt biopsy system for direct LUS-guided fine......-needle aspiration (FNA) and Tru-cut biopsies. PATIENTS AND METHODS: LUS-guided biopsy was performed in 20 patients with upper gastrointestinal tract tumors. The biopsied lesions had either not been previously detected by other imaging modalities or had been inaccessible, or the biopsy sample had been inadequate...... were good or acceptable in 18 patients (90%). Slight needle deviation (material was obtained, but pathological examination was impossible owing...
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[Sleep disorder of schizophrenia treated with shallow needling: a randomized controlled trial].
Huang, Yanxi; Zheng, Ying
2015-09-01
To compare the clinical effective differences between shallow needling and medication for the sleep disorder of schizophrenia. Ninety-six patients with the sleep disorder of schizophrenia were randomly divided into a shallow needling group and a medication group, 48 cases in each one (one case dropping in the shallow needling group and two cases dropping in the medication group). The same dose paliperidone tablets were adopted in the two groups. In the shallow needling group, the main acupoints were Baihui (GV 20), Shangenxue (Extra) and Ezhongxian (MS 1), and the acupoints based on syndrome differentiation were selected. The shallow needling manipulation was used once a day, 5 times a week. In the medication group, 3 mg eszopiclone tablets were prescribed orally before sleep once every night. The patients were treated for 6 weeks in the two groups. Sleep condition was evaluated by Pittsburgh sleep quality index (PSQI) before and after treatment, and the clinical efficacy and the adverse reaction were assessed by positive and negative symptoms scale (PANSS) and treatment emergent symptom scale (TESS) before and after 2-week, 4-week and 6-week treatment. The clinical effects between the two groups were compared. After treatment in the two groups, both the total scores and the each factor score of the PSQI and the PANSS were apparently decreased (Pshallow needling group was reduced more obviously than that of the medication group (Pshallow needling group (Pshallow needling group was better than that in the medication group after treatment (Pshallow needling group after treatment (P0. 05). At the end of the 6th week, the curative and effective rate was 63. 9% (30/47) and the total effective rate was 95. 8% (45/47) in the shallow needling group;the curative and effective rate was 58. 7% (27/46) and the total effective rate was 91. 3% (42/46) in the medication group. The difference of the effect was not statistically significant between the two groups (P>0. 05). The
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A comparison of epicuticular wax of Pinus sylvestris needles from three sites in Ireland
International Nuclear Information System (INIS)
Donnelly, A.; Dowding, P.
1994-01-01
Three forest stands of Pinus sylvestris were chosen for comparison in Ireland. Needles from three year classes were collected. Cuticular transpiration curves showed that the rate of water loss from 1-year-old needles was faster than either 2-year-old or current-year needles at all sites. The amount of epicuticular wax extracted was similar to that reported in the literature. Needle wettability increased with needle age. Amorphous wax coverage was estimated using scanning electron microscopy (SEM) and was found to increase with needle age. Algal cells were noted on needles of all ages at one site and appeared to affect transpiration and microroughness. The presence of fungal hyphae was also noted. (orig.)
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EUS-Guided Needle-Based Confocal Laser Endomicroscopy
DEFF Research Database (Denmark)
Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra
2015-01-01
Endoscopic ultrasound (EUS) has emerged as an excellent tool for imaging the gastrointestinal tract, as well as surrounding structures. EUS-guided fine-needle aspiration (EUS-FNA) has become the standard of care for the tissue sampling of a variety of masses and lymph nodes within and around...... the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure...... that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve...
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Achievement of needle-like focus by engineering radial-variant vector fields.
Gu, Bing; Wu, Jia-Lu; Pan, Yang; Cui, Yiping
2013-12-16
We present and demonstrate a novel method for engineering the radial-variant polarization on the incident field to achieve a needle of transversally polarized field without any pupil filters. We generate a new kind of localized linearly-polarized vector fields with distributions of states of polarization (SoPs) describing by the radius to the power p and explore its tight focusing, nonparaxial focusing, and paraxial focusing properties. By tuning the power p, we obtain the needle-like focal field with hybrid SoPs and give the formula for describing the length of the needle. Experimentally, we systematically investigate both the intensity distributions and the polarization evolution of the optical needle by paraxial focusing the generated vector field. Such an optical needle, which enhances the light-matter interaction, has intriguing applications in optical microma-chining and nonlinear optics.
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Knowledge, attitude and practices about needle stick injuries in health care workers
International Nuclear Information System (INIS)
Waqar, S.H.; Siraj, M.U.; Razzaq, Z.; Malik, Z.I.; Zahid, M.A.
2011-01-01
Objectives: To assess knowledge, attitude and practices about needle stick Injuries in health care workers. Study type, settings and duration: Hospital based study carried out at Pakistan Institute of Medical Sciences, Islamabad, from August 2010 to November 2010. Subjects and Methods: A self administered 19 items questionnaire was prepared which contained information about needle stick injuries, its awareness, frequency of injury and the protocols that were followed after an injury had occurred. These questionnaires were given to 500 health care workers working in different wards and theaters of the hospital after obtaining their informed written consent. The health care workers included doctors, nurses and paramedical staff of Pakistan Institute of Medical Sciences, Islamabad. The data was entered and analyzed using SPSS version 15. Results: A total of 500 health care workers filled the questionnaire and returned it. Out of these 416(83.2%) reported ever experiencing needle stick injuries in their professional life. Health care workers working in Emergency department were most frequently affected (65%) followed by those working in different wards (27%) and operation theatre (8%). Most (93.6%) workers had knowledge about needle stick injuries and only 6.4% were not aware of it. Needle stick injury occurred from a brand new (unused) syringe in 51.2% cases, while in 32.8% cases, the needle caused an injury after it had been used for an injection. In 5% cases, injury occurred with blood stained needles. The commonest reasons for needle injury in stick injuries were heavy work load (36.8%) followed by hasty work (33.6%) and needle recapping (18.6%). About 66% health care workers were already vaccinated against hepatitis B. Only 13% workers followed universal guidelines of needle stick injuries and no case was reported to hospital authorities. Conclusions: Health care workers had inadequate knowledge about the risk associated with needle stick injuries and do not
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Evaluating the advances and use of hypodermic needles in dentistry.
Boynes, Sean G
2014-10-01
Different injection techniques and patient management methodologies have been proposed to decrease the fear patients may have concerning dental needles. Dental providers should have an understanding of the technological advances, changes in techniques, and patient perceptions associated with the hypodermic needle. This article provides an overview of the pain perception process associated with dental injections. It reviews the two main sensory nerve fibers associated with injection pain and discusses needle properties as well as complications and adverse occurrences.
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Development of Needle Insertion Manipulator for Central Venous Catheterization
Kobayashi, Yo; Hong, Jaesung; Hamano, Ryutaro; Hashizume, Makoto; Okada, Kaoru; Fujie, Masakatsu G.
Central venous catheterization is a procedure, which a doctor insert a catheter into the patient’s vein for transfusion. Since there are risks of bleeding from arterial puncture or pneumothorax from pleural puncture. Physicians are strictly required to make needle reach up into the vein and to stop the needle in the middle of vein. We proposed a robot system for assisting the venous puncture, which can relieve the difficulties in conventional procedure, and the risks of complication. This paper reports the design structuring and experimental results of needle insertion manipulator. First, we investigated the relationship between insertion force and angle into the vein. The results indicated that the judgment of perforation using the reaction force is possible in case where the needling angle is from 10 to 20 degree. The experiment to evaluate accuracy of the robot also revealed that it has beyond 0.5 mm accuracy. We also evaluated the positioning accuracy in the ultrasound images. The results displays that the accuracy is beyond 1.0 mm and it has enough for venous puncture. We also carried out the venous puncture experiment to the phantom and confirm our manipulator realized to make needle reach up into the vein.
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Chan, Tony; Dejong, Frederik J.
1993-01-01
The Gas Generator Oxidizer Turbine (GGOT) Blade is being analyzed by various investigators under the NASA MSFC-sponsored Turbine Stage Technology Team design effort. The present work concentrates on the tip clearance region flow and associated losses; however, flow details for the passage region are also obtained in the simulations. The present calculations simulate the rotor blade row in a rotating reference frame with the appropriate coriolis and centrifugal acceleration term included in the momentum equations. The upstream computational boundary is located about one axial chord from the blade leading edge. The boundary conditions at this location have been determined by Pratt & Whitney using an Euler analysis without the vanes to obtain approximately the same flow profiles at the rotor as were obtained with the Euler stage analysis including the vanes. Inflow boundary layer profiles are then constructed assuming the skin friction coefficient at both the hub and the casing. The downstream computational boundary is located about one axial chord from the blade trailing edge, and the circumferentially averaged static pressure at this location was also obtained from the P&W Euler analysis. Results obtained for the 3-D baseline GGOT geometry at the full scale design Reynolds number show a region of high loss in the region near the casing. Particle traces in the near tip region show vortical flow behavior of the fluid which passes through the clearance region and exits at the downstream edge of the gap. In an effort to reduce clearance flow losses, the mini-shroud concept was proposed by the Pratt & Whitney design team. Calculations were performed on the GGO geometry with the mini-shroud. Results of these calculations indicate that the mini-shroud does not significantly affect the flow in the passage region, and although the tip clearance flow is different, the mini-shroud does not seem to prevent the above-mentioned vortical flow behavior. Since both flow distortion
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Teleoperation of steerable flexible needles by combining kinesthetic and vibratory feedback.
Pacchierotti, Claudio; Abayazid, Momen; Misra, Sarthak; Prattichizzo, Domenico
2014-01-01
Needle insertion in soft-tissue is a minimally invasive surgical procedure that demands high accuracy. In this respect, robotic systems with autonomous control algorithms have been exploited as the main tool to achieve high accuracy and reliability. However, for reasons of safety and responsibility, autonomous robotic control is often not desirable. Therefore, it is necessary to focus also on techniques enabling clinicians to directly control the motion of the surgical tools. In this work, we address that challenge and present a novel teleoperated robotic system able to steer flexible needles. The proposed system tracks the position of the needle using an ultrasound imaging system and computes needle's ideal position and orientation to reach a given target. The master haptic interface then provides the clinician with mixed kinesthetic-vibratory navigation cues to guide the needle toward the computed ideal position and orientation. Twenty participants carried out an experiment of teleoperated needle insertion into a soft-tissue phantom, considering four different experimental conditions. Participants were provided with either mixed kinesthetic-vibratory feedback or mixed kinesthetic-visual feedback. Moreover, we considered two different ways of computing ideal position and orientation of the needle: with or without set-points. Vibratory feedback was found more effective than visual feedback in conveying navigation cues, with a mean targeting error of 0.72 mm when using set-points, and of 1.10 mm without set-points.
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An Optical Fiber Bundle Sensor for Tip Clearance and Tip Timing Measurements in a Turbine Rig
Directory of Open Access Journals (Sweden)
María Asunción Illarramendi
2013-06-01
Full Text Available When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on the turbine casing. To eliminate the influence of light source intensity variations and blade surface reflectivity, the sensing principle is based on the quotient of the voltages obtained from the two receiving bundle legs. A discrepancy lower than 3% with respect to a commercial sensor was observed in tip clearance measurements. Regarding tip timing measurements, the travel wave spectrum was obtained, which provides the average vibration amplitude for all blades at a particular nodal diameter. With this approach, both blade-tip timing and tip clearance measurements can be carried out simultaneously. The results obtained on the test turbine rig demonstrate the suitability and reliability of the type of sensor used, and suggest the possibility of performing these measurements in real turbines under real working conditions.
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A Dual Sensor for pH and Hydrogen Peroxide Using Polymer-Coated Optical Fibre Tips.
Purdey, Malcolm S; Thompson, Jeremy G; Monro, Tanya M; Abell, Andrew D; Schartner, Erik P
2015-12-17
This paper demonstrates the first single optical fibre tip probe for concurrent detection of both hydrogen peroxide (H₂O₂) concentration and pH of a solution. The sensor is constructed by embedding two fluorophores: carboxyperoxyfluor-1 (CPF1) and seminaphtharhodafluor-2 (SNARF2) within a polymer matrix located on the tip of the optical fibre. The functionalised fibre probe reproducibly measures pH, and is able to accurately detect H₂O₂ over a biologically relevant concentration range. This sensor offers potential for non-invasive detection of pH and H₂O₂ in biological environments using a single optical fibre.
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Robotic Needle Guide for Prostate Brachytherapy: Clinical Testing of Feasibility and Performance
Song, Danny Y; Burdette, Everette C; Fiene, Jonathan; Armour, Elwood; Kronreif, Gernot; Deguet, Anton; Zhang, Zhe; Iordachita, Iulian; Fichtinger, Gabor; Kazanzides, Peter
2010-01-01
Purpose Optimization of prostate brachytherapy is constrained by tissue deflection of needles and fixed spacing of template holes. We developed and clinically tested a robotic guide towards the goal of allowing greater freedom of needle placement. Methods and Materials The robot consists of a small tubular needle guide attached to a robotically controlled arm. The apparatus is mounted and calibrated to operate in the same coordinate frame as a standard template. Translation in x and y directions over the perineum ±40mm are possible. Needle insertion is performed manually. Results Five patients were treated in an IRB-approved study. Confirmatory measurements of robotic movements for initial 3 patients using infrared tracking showed mean error of 0.489 mm (SD 0.328 mm). Fine adjustments in needle positioning were possible when tissue deflection was encountered; adjustments were performed in 54/179 (30.2%) needles placed, with 36/179 (20.1%) adjustments of > 2mm. Twenty-seven insertions were intentionally altered to positions between the standard template grid to improve the dosimetric plan or avoid structures such as pubic bone and blood vessels. Conclusions Robotic needle positioning provided a means of compensating for needle deflections as well as the ability to intentionally place needles into areas between the standard template holes. To our knowledge, these results represent the first clinical testing of such a system. Future work will be incorporation of direct control of the robot by the physician, adding software algorithms to help avoid robot collisions with the ultrasound, and testing the angulation capability in the clinical setting. PMID:20729152
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Tips for Living with Scleroderma
... Patients Tips for Living Tips for Living with Scleroderma Ways to help manage your symptoms The Scleroderma ... help find improved therapies and a cure for scleroderma! Your gift today will be matched to have ...
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... or bypass, without the risks that accompany open surgery. TIPS is a minimally invasive procedure that typically has a shorter recovery time than surgery. Your TIPS should have less of an effect ...
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A novel fabrication method of silicon nano-needles using MEMS TMAH etching techniques
International Nuclear Information System (INIS)
Yan Sheping; Xu Yang; Yang Junyi; Wang Huiquan; Jin Zhonghe; Wang Yuelin
2011-01-01
Nano-needles play important roles in nanoscale operations. However, current nano-needle fabrication is usually expensive and controling the sizes and angles is complicated. We have developed a simple and low cost silicon nano-needle fabrication method using traditional microelectromechanical system (MEMS) tetramethyl ammonium hydroxide (TMAH) etching techniques. We take advantage of the fact that the decrease of the silicon etch rate in TMAH solutions exhibits an inverse fourth power dependence on the boron doping concentration in our nano-needle fabrication. Silicon nano-needles, with high aspect ratio and sharp angles θ as small as 2.9 deg., are obtained, which could be used for bio-sensors and nano-handling procedures, such as penetrating living cells. An analytic model is proposed to explain the etching evolution of the experimental results, which is used to predict the needle angle, length, and etching time. Based on our method, nano-needles with small acute angle θ can be obtained.
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International Nuclear Information System (INIS)
Harrach, Michael F.; Drossel, Barbara
2014-01-01
We perform molecular dynamics simulations to observe the structure and dynamics of water using different water models (TIP3P, TIP4P, TIP5P) at ambient conditions, constrained by planar walls, which are either modeled by smooth potentials or regular atomic lattices, imitating the honeycomb-structure of graphene. We implement walls of different hydroaffinity, different lattice constant, and different types of interaction with the water molecules. We find that in the hydrophobic regime the smooth wall generally represents a good abstraction of the atomically rough walls, while in the hydrophilic regime there are noticeable differences in structure and dynamics between all stages of wall roughness. For a small lattice constant however the smooth and the atomically rough wall still share a number of structural and dynamical similarities. Out of the three water models, TIP5P water shows the largest degree of tetrahedral ordering and is often the one that is least perturbed by the presence of the wall
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Lumbar punction: comparison between an atraumatic and a traumatic punction needle
Directory of Open Access Journals (Sweden)
Tina Bregant
2017-03-01
Full Text Available Background: Lumbar puncture is a standardized, routine diagnostic procedure in the diagnosis of neurological diseases. Post-duarl puncture headache (PDPH is a common complication which occurs in 10 to 30 % of patients. Although the incidence of PDPH is much lower with the use of small, non-cutting needles, neurologists in Slovenia routinely use the classical traumatic spinal needles.Methods: In the article we provide an overview of a research concerned with the use of traumatic and atraumatic needles in the procedure with the emphasis on complications of the lumbar puncture. We present American and European recommendations for lumbar puncture procedure.Conclusions: International recommendations for neurologists advise the use of atraumatic spinal needles for lumbar puncture. We recommend to Slovenian neurologists to start using the atraumatic needles for elective lumbar punctures and hence provide neurological patients with better quality and cheaper long-term care.
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RANS computations of tip vortex cavitation
Decaix, Jean; Balarac, Guillaume; Dreyer, Matthieu; Farhat, Mohamed; Münch, Cécile
2015-12-01
The present study is related to the development of the tip vortex cavitation in Kaplan turbines. The investigation is carried out on a simplified test case consisting of a NACA0009 blade with a gap between the blade tip and the side wall. Computations with and without cavitation are performed using a R ANS modelling and a transport equation for the liquid volume fraction. Compared with experimental data, the R ANS computations turn out to be able to capture accurately the development of the tip vortex. The simulations have also highlighted the influence of cavitation on the tip vortex trajectory.
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... filtered out by the liver. The TIPS may cause too much of these substances to bypass the ...
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... then placed in this tunnel to keep the pathway open. Patients who typically need a TIPS have ... and stomach. A TIPS procedure involves creating a pathway through the liver that connects the portal vein ( ...
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... and/or hydrothorax (in the chest). Budd-Chiari syndrome , a blockage in one or more veins that ... intentionally to solve the problem. Although extremely rare, children may also require a TIPS procedure. TIPS in ...
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... the esophagus and stomach. A TIPS procedure involves creating a pathway through the liver that connects the ... diseases. This can result in significant challenges in creating the TIPS. top of page Additional Information and ...
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Full Text Available ... TIPS. top of page What are some common uses of the procedure? A TIPS is used to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...