Sample records for catheters hollow needles

  1. Estimating needle-tissue interaction forces for hollow needles using fiber Bragg grating sensors (United States)

    Kumar, Saurabh; Shrikanth, V.; Bharadwaj, Amrutur; Asokan, Sundarrajan; Bobji, M. S.


    Brachytherapy and neurological procedures can benefit from real-time estimation of needle-tissue interaction forces, specifically for robotic or robot-assisted procedures. Fiber Bragg Grating Sensors provide advantages of very small size and electromagnetic immunity for use in measurement of the forces directly at the needle tip. This has advantages compared to measurements at the needle shaft which require extensive models of the friction between needle and tissues with varying depth. This paper presents the measurement of tip forces for a hollow needle and compensation for bending when encountering regions of varying stiffness in phantoms with multiple layers prepared using Polydimethylsiloxane.

  2. Silica needle template fabrication of metal hollow microneedle arrays (United States)

    Zhu, M. W.; Li, H. W.; Chen, X. L.; Tang, Y. F.; Lu, M. H.; Chen, Y. F.


    Drug delivery through hollow microneedle (HMN) arrays has now been recognized as one of the most promising techniques because it minimizes the shortcomings of the traditional drug delivery methods and has many exciting advantages—pain free and tunable release rates, for example. However, this drug delivery method has been hindered greatly from mass clinical application because of the high fabrication cost of HMN arrays. Hence, we developed a simple and cost-effective procedure using silica needles as templates to massively fabricate HMN arrays by using popular materials and industrially applicable processes of micro- imprint, hot embossing, electroplating and polishing. Metal HMN arrays with high quality are prepared with great flexibility with tunable parameters of area, length of needle, size of hollow and array dimension. This efficient and cost-effective fabrication method can also be applied to other applications after minor alterations, such as preparation of optic, acoustic and solar harvesting materials and devices.

  3. A new modified technique of laparoscopic needle catheter jejunostomy: a 2-year follow-up study

    Directory of Open Access Journals (Sweden)

    Ye P


    Full Text Available Peng Ye, Liping Zeng, Fenghao Sun, Zhou An, Zhoubin Li, Jian Hu Department of Thoracic Surgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China Background: The aim of this study was to establish a modified technique for performing laparoscopic needle catheter jejunostomy. Methods: From May 2011 to October 2013, laparoscopic needle catheter jejunostomy was performed in 21 patients with esophageal cancer. During the procedure, jejunal inflation was performed via a percutaneous 20-gauge intravenous catheter to facilitate the subsequent puncture of the jejunal wall by the catheter needle. The success rate, procedure time, complications, and short-term outcomes were evaluated. Results: All laparoscopic needle catheter jejunostomies were technically successful, with no perioperative mortality or conversion to a laparotomy. The operation required a mean time of 51.4±14.2 (range 27–80 minutes, and operative bleeding range was 5–20 mL. There was one reoperation required for one patient on postoperative day 5, because the feeding tube was accidentally pulled out during sleep, by patient himself, and the second laparoscopic jejunostomy for this patient was performed successfully. One patient had puncture site pain and was successfully treated with oral analgesics. Other complications, such as gastrointestinal bleeding, intestinal perforation, intestinal obstruction, tube dysfunction, pericatheter leakage, and infection at the skin insertion site, were not observed. The 30-day mortality rate was 4.8% (one out of 21, which was not attributed to the procedure. Enteral nutrition was gradually administered 24–48 hours after operation. Conclusion: The novel modified technique of laparoscopic needle catheter jejunostomy is a technically feasible, with a high technical success rate and low complication rate. Its specific advantage is simplicity and safety, and this modified approach can be

  4. Transconjunctival sutureless intrascleral intraocular lens fixation using intrascleral tunnels guided with catheter and 30-gauge needles. (United States)

    Takayama, Kohei; Akimoto, Masayuki; Taguchi, Hogara; Nakagawa, Satoko; Hiroi, Kano


    We invented a new method for fixing an intraocular lens (IOL) in the scleral tunnel without using a wide conjunctival incision. Modified bent catheter needles were used to penetrate the IOL haptics through the sclerotomy sites. The IOL haptics were inserted into 30-guage (G) scleral tunnels guided by double 30-G needles piercing the sclera. All procedures were performed through the conjunctiva without wide incision. The procedure does not require special forceps, trocars or fibrin glue, only catheter and 30-G needles. The aid of an assistant was not required to support the IOL haptic. The procedures were easily learnt based on our previous method. As with other transconjunctival sutureless surgeries, patients feel less discomfort and the conjunctiva can be conserved for future glaucoma surgery. Complications included two cases of vitreous haemorrhage (16.7%), and one case each of postoperative hypotony, and iris capture (8.3%). Astigmatism induced by intraocular aberration was the same as we reported previously. Our method for fixing the IOL into the scleral tunnel is innovative, less expensive, less invasive and quick. This modified method is a good alternative for fixing IOL haptics into the sclera.

  5. Interaction between hollow needles - electric field, light emission and ozone generation study in multineedle to plate electrical discharge (United States)

    Kriha, Vitezslav


    Multi hollow needle to plate electrical discharges in air are studied as ozone sources. Dependence of ozone concentration as an function of applied voltage, discharge current, mutual hollow needles position and electrical connection, working gas flow rate, distances between needles tips and plate electrode, visible light emission was measured experimentally in these systems. Electric field was numerically modeled. Light emission and electrical field distributions were compared. Coming from light emission and electric field a model of energy density spatial distribution was built. This model was finally compared with ozone generation.

  6. Instrument validation for peripheral venous puncture with over-the-needle catheter

    Directory of Open Access Journals (Sweden)

    Aminna Kelly Almeida de Oliveira


    Full Text Available Objective: to validate an instrument for the assessment of the peripheral venipuncture technique with over-the-needle catheter. Methods: methodological, transversal study developed with 24 judge nurses, professors of the subject semiology and/or physical examination techniques, with at least 1 year of experience in those disciplines in three stages: preparation of checklist; submission to the judges for evaluation; and content validation through the application of the Kappa index. Results: out of the 26 items of the instrument, only 2 did not have Kappa index and content validity index within the established parameters. Out of these 24 items, 7 showed perfect concordance index, 10 great and 7 good. Conclusion: the instrument had representation and extension about the area of ​​interest.

  7. A prospective randomised trial comparing insertion success rate and incidence of catheterisation-related complications for subclavian venous catheterisation using a thin-walled introducer needle or a catheter-over-needle technique. (United States)

    Kim, E; Kim, B G; Lim, Y J; Jeon, Y T; Hwang, J W; Kim, H C; Choi, Y H; Park, H P


    In clinical practice, both a thin-walled introducer needle and catheter-over-needle technique can be used to allow insertion of a guidewire during central venous catheterisation using the Seldinger technique. We compared the incidence of catheterisation-related complications (arterial puncture, haemothorax, pneumothorax, haematoma and catheter tip malposition) and insertion success rate for these two techniques in patients requiring right-sided subclavian central venous catheterisation. A total of 414 patients requiring infraclavicular subclavian venous catheterisation were randomly allocated to either a thin-walled introducer needle (needle group, n = 208) or catheter-over-needle technique (catheter group, n = 206). The catheterisation-related complication rate was lower in the needle group compared with the catheter group (5.8% vs. 15.5%; p = 0.001). Overall insertion success rates were similar (97.1% and 92.7% in the needle and catheter groups respectively; p = 0.046), although the first-pass success rate was higher in the needle group (62.0% vs. 35.4%; p technique for right-sided infraclavicular subclavian venous catheterisation.

  8. SU-F-BRA-03: Integrating Novel Electromagnetic Tracking Hollow Needle Assistance in Permanent Implant Brachytherapy Procedures

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    Racine, E; Hautvast, G; Binnekamp, D [Philips Group Innovation - Biomedical Systems, Eindhoven (Netherlands); Beaulieu, L [Centre Hospitalier Univ de Quebec, Quebec, QC (Canada)


    Purpose: To report on the results of a complete permanent implant brachytherapy procedure assisted by an electromagnetic (EM) hollow needle possessing both 3D tracking and seed drop detection abilities. Methods: End-to-end in-phantom EM-assisted LDR procedures were conducted. The novel system consisted of an EM tracking apparatus (NDI Aurora V2, Planar Field Generator), a 3D US scanner (Philips CX50), a hollow needle prototype allowing 3D tracking and seed drop detection and a specially designed treatment planning software (Philips Healthcare). A tungsten-doped 30 cc spherical agarose prostate immersed in gelatin was used for the treatment. A cylindrical shape of 0.8 cc was carved along its diameter to mimic the urethra. An initial plan of 26 needles and 47 seeds was established with the system. The plan was delivered with the EM-tracked hollow needle, and individual seed drop locations were recorded on the fly. The phantom was subsequently imaged with a CT scanner from which seed positions and contour definitions were obtained. The DVHs were then independently recomputed and compared with those produced by the planning system, both before and after the treatment. Results: Of the 47 seeds, 45 (96%) were detected by the EM technology embedded in the hollow needle design. The executed plan (from CT analysis) differed from the initial plan by 2%, 14% and 8% respectively in terms of V100, D90 and V150 for the prostate, and by 8%, 7% and 10% respectively in terms of D5, V100 and V120 for the urethra. Conclusion: The average DVH deviations between initial and executed plans were within a 5% tolerance imposed for this proof-of-concept assessment. This relatively good concordance demonstrates the feasibility and potential benefits of combining EM tracking and seed drop detection for real-time dosimetry validation and assistance in permanent implant brachytherapy procedures. This project has been entirely funded by Philips Healthcare.

  9. The Wiley Spinal Catheter-Over-Needle System for Continuous Spinal Anesthesia: A Case Series of 5 Cesarean Deliveries Complicated by Paresthesias and Headaches. (United States)

    McKenzie, Christine P; Carvalho, Brendan; Riley, Edward T


    Intrathecal catheter devices using a catheter-over-needle design and softer flexible material have been introduced to clinical practice with the aim of reducing some of the complications such as postdural puncture headaches and paresthesias seen with previous versions of intrathecal catheters. We present a case series of 5 cesarean deliveries using the Wiley Spinal intrathecal system (Epimed, Johnstown, New York), which was recently approved by the US Food and Drug Administration. The intrathecal catheter system consists of a flexible 23-gauge intrathecal cannula over a 27-gauge pencil-point spinal needle. The placement of the intrathecal catheter was successful in all 5 cases; however, paresthesias in 3 cases and postdural puncture headaches in 2 cases complicated the placement and use of the device. Although the unique catheter-over-needle design facilitates the use of smaller-gauge spinal needles for dural puncture and larger-gauge catheters for medication administration, this case series using the Wiley Spinal suggests that paresthesias and postdural puncture headaches may still limit its widespread utilization. Future studies are needed to determine the true incidence of complications and to determine the role of continuous spinal anesthesia in the obstetric population.

  10. Modelling of Current Density Redistribution in Hollow Needle to Plate Electrical Discharge Designed for Ozone Generation (United States)

    Kriha, Vitezslav


    Non-thermal plasma of atmospheric pressure electrical discharges in flowing air can be used to generation of ozone. We have been observed two modes of discharge burning in a hollow needle to plane electrodes configuration studied in the ozone generation experiments: A low current diffuse mode is characterized by increasing of the ozone production with the discharge current; a high current filamentary mode is disadvantageous for the ozone generation(the ozone production decreases when the discharge current increases). A possible interpretation of this effect is following: The filamentary mode discharge current density is redistributed and high current densities in filaments cores lead to degradation of the ozone generation. Local fields in the discharge can be modified by charged metallic and/or dielectric components (passive modulators) in the discharge space. An interactive numerical model has been developed for this purpose. This model is based on Ferguson's polynomial objects for both the discharge chamber scene modelling and the discharge fields analyzing. This approach allows intuitive modifications of modulators shapes and positions in 3D scene followed by quantitative comparison of the current density distribution with previous configurations.

  11. Is the pharmacokinetics of bupivacaine equivalent after lumbar epidural administration through a needle or a catheter in male and female adults? (United States)

    Faura, Ana; Modamio, Pilar; Blanco, Domingo; Segarra, Ignacio; Lastra, Cecilia F; Izquierdo, Elisenda; Casasín, Tomás; Mariño, Eduardo L


    We assessed possible pharmacokinetic modifications due to different epidural injection techniques using either a needle or a catheter. Adult patients (n=23) undergoing lower abdominal or lower extremity surgery were randomly assigned a single bupivacaine epidural injection anesthesia (0.5%, 15 mL, 0.3 mL/s) through needle or catheter device. Plasma bupivacaine concentration was quantified using a validated HPLC method and non-compartmental pharmacokinetic parameters estimated. CMAX and TMAX were similar in both groups: 952 ± 346 ng/mL, 0.65 ± 0.5 1h in the needle group; 810 ± 307 ng/mL, 0.43 ± 0.29 h in the catheter group respectively. Plasma AUC₀→∞ was also similar in both groups: 3868 ± 1687 ngh/mL for needle versus 4096 ± 1748 ngh/mL using catheter. The catheter group showed slower disposition than the needle group: t₁/₂=3.9 ± 2.3 h, MRT=6.0 ± 3.1 h versus 2.7 ± 1.03 h and 4.5 ± 1.2 h with needle administration respectively though it did not reach statistical significance, Cl/F and V/F were also similar. Lastly, female patients showed significant longer t1/2 after administration through catheter (5.7 ± 2.0 h) than needle (2.7 ± 0.6 h) group (P=0.0279). The device type does not affect the pharmacokinetics which is similar in both groups although sex-based differences might exist.

  12. Needle and catheter colonization in pregnant diabetic patients using the continuous subcutaneous insulin infusion pump. (United States)

    Rivera-Alsina, M E; Willis, S


    The incidence of bacterial colonization and risk of infection associated with the use of continuous insulin infusion pump (CIIP) was examined in 11 pregnant diabetic patients. All patients received instruction on specific aspects of CIIP and needle insertion technique according to the protocol used in our institution. A total of 220 cultures was performed on the subcutaneous needle and connective tubing. There was no clinical evidence of infection. In conclusion, the risk of infectious cutaneous complications in the pregnant diabetic patient using CIIP is not increased over the nonpregnant diabetic population.

  13. Improved transvenous liver biopsy needle

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Matzen, P; Christoffersen, P;


    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....

  14. 留置途径对中心静脉导管感染的影响%Influence of remaining needle on central venous catheter-related infection

    Institute of Scientific and Technical Information of China (English)

    李丽华; 杨筱敏


    Objective To investigate the influence of central venous catheter-related infection among different remaining needle. Methods The infection of central venous catheter with remaining needle in patients of comprehensive ICU was analyzed. Results There was the highest infection rate (31.2%) in femoral vein catheter group, followed by subclavian vein catheter group and jugular vein catheter (13.7%, 15.4%), peripheral venous catheter infection rate was lowest (3.8%). The difference among three groups was statistical significance (P<0. 01 ). Gram-positive bacteria was the major pathogenic bacterium. Conclusion The infection of central venous catheter was correlated with the puncture approach, central venous catheter to adopt the peripheral venous puncture approach may lower significantly catheter-related infection rate.%目的 探讨不同留置途径对中心静脉导管相关性感染的影响.方法 对重症监护病房采用不同途径留置中心静脉导管的患者进行回顾性分析,比较经不同途径留置中心静脉置管而发生感染的差异.结果 股静脉发生感染率最高(31.2%),锁骨下和颈内静脉置管发生感染率次之(13.7%、15.4%),经外周静脉置管发生感染率最低(3.8%),三者差异有显著性(P<0.01),并且感染的致病菌以革兰氏阳性菌为主.结论 中心静脉置管的感染与留置途径有明显的相关性,采用外周静脉置管途径可以明显降低中心静脉置管的感染率.

  15. Analysis of the Improved Indwelling Catheter Technique of Venous In-dwelling Needle%探析静脉留置针置管改进技术

    Institute of Scientific and Technical Information of China (English)



    目的:探讨静脉留置针置管改进技术对穿刺成功率的影响。方法随机选取该院2013年1月-2014年2月期间行静脉留置针穿刺的患者110例,随机分为两组,各55例,对照组实施常规静脉留置针穿刺,观察组采用改进的静脉留置针穿刺。结果观察组的一次穿刺成功率为98.18%,对照组为87.27%;观察组的并发症发生率为11.11%,对照组为6.25%。结论采用改进的静脉留置针置管穿刺,能有效提高穿刺成功率,值得临床推广应用。%Objective To investigate the effect of improved indwelling catheter technique of venous indwelling needle on the suc-cess rate of puncture. Methods 110 cases underwent venous indwelling needle puncture in our hospital from January 2013 to February 2014 were selected and randomly divided into two groups, the control group and the observation group with 55 cases in each. The control group underwent the venous indwelling needle puncture by the conventional technique, while the observation group underwent that by improved technique. Results The one-time success rate of puncture in the observation group was 98.18%, and that in the control group was 87.27%; the incidence of complications in the observation group was 11.11%, and that in the control group was 6.25%. Conclusion Improved indwelling catheter technique for venous indwelling needle puncture can ef-fectively improve the success rate of puncture, so it is worthy of clinical application and promotion.

  16. Catheter Angiography

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    Full Text Available ... an artery through a small incision in the skin. Once the catheter is guided to the area ... small incision (usually a few millimeters) in the skin where the catheter can be inserted into an ...

  17. 探讨空心针灸针治疗慢性腰腿痛的临床疗效分析%To Explore the Hollow Needle Acupuncture Treatment the Clinical Curative Effect of Chronic Lumbocrural Pain

    Institute of Scientific and Technical Information of China (English)

    张惜瑜; 杨玲


    目的:探讨空心针灸针治疗慢性腰腿痛的临床疗效分析。方法笔者选取我院2010年2月至2013年2月收治的300例慢性腰腿痛患者作为研究对象,按照随机分组原则分为对照组与观察组。其中对照组150例采用常规针刺治疗,刺点为肾俞、膀胱俞、阿是穴。观察组150例采用治疗组接受常规针刺治疗,穴取肾俞、膀胱俞、阿是穴加穴位注射法,两组患者均留针20 min。结果对照组150例患者有效率为87.2%;观察组150例患者有效率为97.3%。两组疗效差异具有统计学意义(P>0.05)。结论空心针灸针治疗效果要明显高于常规针灸治疗,值得临床大力推广。%Objective To explore the clinical effect of treating chronic lumbocrural pain hollow acupuncture needle. Methods We selected 300 patients with chronic low back pain patients in our hospital from 2010 February to 2013 February were as the research object, according to the principle of randomly divided into control group and observation group. Among the 150 cases in the control group treated with conventional acupuncture, acupuncture point, bladder Yu, Shenshu point. Results 150 patients in the control group the effective rate was 87.2%;150 patients in observation group efficiency is 97.3%. A statistically significant difference between the two groups (P>0.05). Conclusion The hollow needle for acupuncture treatment is more effective than routine acupuncture treatment, worthy of clinical popularization.

  18. Magnetic-field navigation for catheters: integrated chip for triple blood sampling

    NARCIS (Netherlands)

    Mols, B.


    Catheters are semi-rigid, hollow plastic tubes that are indispensable when it comes to local surgery inside the heart,brain,arms, legs, or lungs. But how can a surgeon tell whether the catheter is going the right way? Most hospitals still use x-ray methods to check the catheters progress. To navigat

  19. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... iodine. If angiography is essential, a variety of methods is used to decrease risk of allergy: You ...

  20. Catheter Angiography

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    Full Text Available ... injection of contrast material to examine blood vessels in key areas of the body for abnormalities such ... makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography produces very detailed, ...

  1. Catheter Angiography

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    Full Text Available ... of page What are some common uses of the procedure? Catheter angiography is used to examine blood ... an hour away. top of page What does the equipment look like? The equipment typically used for ...

  2. Catheter Angiography

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    Full Text Available ... atherosclerosis (plaque). The use of a catheter makes it possible to combine diagnosis and treatment in a ... the aorta in the chest or abdomen or its major branches. show the extent and severity of ...

  3. A novel suture method to place and adjust peripheral nerve catheters

    DEFF Research Database (Denmark)

    Rothe, C.; Steen-Hansen, C.; Madsen, M. H.;


    We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial...

  4. Urinary catheters (United States)

    ... incontinence. There is no tube placed inside the penis. Instead, a condom-like device is placed over the penis. A tube leads from this device to a ... too small Bladder spasms Constipation The wrong balloon size Urinary tract infections POSSIBLE COMPLICATIONS Complications of catheter ...

  5. Catheter Angiography

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. ...

  6. Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia. (United States)

    Ahn, H J; Choi, D H; Kim, C S


    Paraesthesia during regional anaesthesia is an unpleasant sensation for patients and, more importantly, in some cases it is related to neurological injury. Relatively few studies have been conducted on the frequency of paraesthesia during combined spinal epidural anaesthesia. We compared two combined spinal epidural anaesthesia techniques: the needle-through-needle technique and the double segment technique in this respect. We randomly allocated 116 parturients undergoing elective Caesarean section to receive anaesthesia using one of these techniques. Both techniques were performed using a 27G pencil point needle, an 18G Tuohy needle, and a 20G multiport epidural catheter from the same manufacturer. The overall frequency of paraesthesia was higher in the needle-through-needle technique group (56.9% vs. 31.6%, p = 0.011). The frequency of paraesthesia at spinal needle insertion was 20.7% in the needle-through-needle technique group and 8.8% in the double segment technique group; whereas the frequency of paraesthesia at epidural catheter insertion was 46.6% in the needle-through-needle technique group and 24.6% in the double segment technique group.

  7. Technique of Peritoneal Catheter Placement under Fluroscopic Guidance

    Directory of Open Access Journals (Sweden)

    Ahmed Kamel Abdel-Aal


    Full Text Available Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

  8. Hemodialysis Tunneled Catheter Noninfectious Complications (United States)

    Miller, Lisa M.; MacRae, Jennifer M.; Kiaii, Mercedeh; Clark, Edward; Dipchand, Christine; Kappel, Joanne; Lok, Charmaine; Luscombe, Rick; Moist, Louise; Oliver, Matthew; Pike, Pamela; Hiremath, Swapnil


    Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

  9. Knotting of a Cervical Epidural Catheter in the Patient with Post-Herpetic Neuralgia: A Rare Complication (United States)

    Park, Jong Taek; Cho, Dong Woo; Lee, Young Bok


    Epidural block is achieved either by single injection of local anesthetic through an epidural needle or as a continuous block by infusion pump through an epidural catheter. Complications associated with epidural catheters include breakage, entrapment, and knotting. Knotting of epidural catheters is very rare, but knotting in lumbar epidural catheters has been reported in a number of studies, and most of these cases involved removal difficulty. We report a case in which we inserted a cervical epidural catheter in a patient who was experiencing severe post-herpetic neuralgia and then removed the knotted catheter without complications. PMID:28261560

  10. A novel suture method to place and adjust peripheral nerve catheters

    DEFF Research Database (Denmark)

    Rothe, C.; Steen-Hansen, C.; Madsen, M. H.;


    We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial plac...... successful and 42/43 secondary placements successful by ultrasound, confirmed in 10/10 cases by magnetic resonance imaging....

  11. Guidance of interventions in subintimal recanalization and fenestration of dissection membranes using a novel dual-lumen intravascular ultrasound catheter; Steuerung der Interventionen bei subintimaler Rekanalisation und Fenestration von Dissektionsmembranen durch einen neuartigen zweilumigen intravaskulaeren Ultraschallkatheter

    Energy Technology Data Exchange (ETDEWEB)

    Kickuth, R.; Ludwig, K.C.; Triller, J. [Dept. Radiologie, Neuroradiologie und Nuklearmedizin, Inst. fuer Diagnostische Interventionelle und Paediatrische Radiologie, Inselspital (Switzerland); Do, D.D.; Husmann, M.; Baumgartner, I. [Dept. Herz und Gefaesse DHGE, Klinik und Poliklinik fuer Angiologie (Switzerland)


    Purpose: To evaluate the feasibility and effectiveness of IVUS-guided puncture for gaining controlled target lumen reentry in subintimal recanalization of chronic iliac/femoral artery occlusions and in fenestration of aortic dissections. Materials and Methods: Between 5/2004 and 12/2005 12 consecutive patients (7 male, 5 female; mean age 64.6{+-}12.0 years) with chronic critical limb ischemia and ischemic complications of aortic dissection were treated using the Pioneer trademark catheter. This 6.2-F dual-lumen catheter combines a 20-MHz IVUS transducer with a pre-shaped extendable, hollow 24-gauge nitinol needle. This coaxial needle allows real-time IVUS-guided puncture of the target lumen and after successful reentry a 0.014'' guidewire may be advanced through the needle into the target lumen. 7 patients were treated for aortic dissection and 5 patients (with failed previous attempts at subintimal recanalization) for chronic arterial occlusion. Patients with aortic dissection (5 type A dissections, 2 type B dissections) had developed renal ischemia (n=2), renal and mesenteric ischemia (n=2), or low extremity ischemia (n=3). Patients with chronic arterial occlusions (2 common iliac artery occlusions, 3 superficial femoral artery occlusions) experienced ischemic rest pain (n=4), and a non-healing foot ulcer (n=1). Results: The technical success rate using the Pioneer catheter was 100%. The recanalization/fenestration time was 37{+-}12 min. Procedure-related complications did not occur. In 10 cases a significant improvement of clinical symptoms was evident. One patient with aortic dissection and ischemic paraplegia required subsequent surgical intervention. One patient had persistent ischemic rest pain despite successful recanalization of a superficial femoral artery occlusion. (orig.)

  12. Advanced Imaging Catheter: Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Krulevitch, P; Colston, B; DaSilva, L; Hilken, D; Kluiwstra, J U; Lee, A P; London, R; Miles, R; Schumann, D; Seward, K; Wang, A


    Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area. The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body) relative to

  13. Central venous catheters and catheter locks in children with cancer

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Møller, Jens Kjølseth; Schrøder, Henrik


    To determine if the catheter lock taurolidine can reduce the number of catheter-related bloodstream infections (CRBSI) in pediatric cancer patients with tunneled central venous catheters (CVC).......To determine if the catheter lock taurolidine can reduce the number of catheter-related bloodstream infections (CRBSI) in pediatric cancer patients with tunneled central venous catheters (CVC)....

  14. Needle autopsy

    Directory of Open Access Journals (Sweden)

    Philip Davis Marsden


    Full Text Available Often in tropical practice there is not time or conditions to do a proper autopsy on a patient who has died. A needle biopsy technique is described for limited closed autopsy examination to clariffy organ histology. In this way the clinician may resolve puzzling fatal disease.Muitas vezes, em clínicas de países tropicais, não há tempo nem condições para se realizar uma necropsia adequada em um paciente que foi a óbito. Um técnica de biópsia por punção é descrita para fins de exame em necropsia limitadamente fechada, para esclarecimento da histologia do órgão. Dessa maneira, o clínico pode resolver enigmas de doenças fatais.

  15. Spinal cord injury caused by direct damage by local anaesthetic infiltration needle

    NARCIS (Netherlands)

    Absalom, AR; Martinelli, G; Scott, NB


    We describe a case of spinal cord injury caused by direct trauma from a local anaesthetic infiltration needle. During local anaesthetic infiltration before placement of an epidural catheter, the patient suddenly rolled over onto her back, causing the infiltrating needle to advance all the way to its

  16. Percutaneous catheter drainage of intrapulmonary fluid collection

    Energy Technology Data Exchange (ETDEWEB)

    Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H. [Gyeongsang National University Hospital, Chinju (Korea, Republic of)


    With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment.

  17. Central venous catheter - flushing (United States)

    ... during cancer treatment Bone marrow transplant - discharge Central venous catheter - dressing change Peripherally inserted central catheter - flushing Sterile technique Surgical wound care - open Review Date 9/22/2016 Updated by: ...

  18. Percutaneously inserted long-term central venous catheters in pigs of different sizes. (United States)

    Larsson, N; Claesson Lingehall, H; Al Zaidi, N; Claesson, J; Jensen-Waern, M; Lehtipalo, S


    Pigs are used for long-term biomedical experiments requiring repeated injections, infusions and collections of blood samples. Thus, it is necessary for vascular catheters to be indwelling to avoid undue stress to the animals and the use of restraints. We propose a refined model of percutaneous insertion of long-term central venous catheters to minimize the surgical trauma and postoperative complications associated with catheter insertion. Different sizes of needles (18 Ga versus 21 Ga) for initial puncture of the veins were compared. In conventional pigs weighing less than 30 kg, catheter insertion may be facilitated by using a microintroducer set with a 21 Ga needle. In pigs weighing 50 kg, a standard 18 Ga needle may be preferable.

  19. Optical Coherence Tomography in a Needle Format (United States)

    Lorenser, Dirk; McLaughlin, Robert A.; Sampson, David D.

    In this chapter, we review the technology and applications of needle probes for optical coherence tomography (OCT). Needle probes are miniaturized fiber-optic probes that can be mounted inside hypodermic needles, allowing them to be inserted deep into the body during OCT imaging. This overcomes the very limited imaging depth of OCT of only 2-3 mm in biological tissue, enabling access to deep-tissue locations that are beyond the reach of free-space optical scan heads or catheters. This chapter provides an in-depth review of the current state-of-the art in needle probe technology, including optical design and fabrication, scan mechanisms (including three-dimensional scanning), and integration into OCT systems. It also provides an overview of emerging applications of this fascinating new imaging tool in areas such as cancer diagnosis, pulmonary imaging, imaging of the eye and imaging of the brain. Finally, two case studies are presented, illustrating needle-based OCT imaging in breast cancer and lungs.

  20. Hollow MEMS

    DEFF Research Database (Denmark)

    Larsen, Peter Emil

    a hollow MEMS sensor has been designed, fabricated and tested. Combined density, viscosity, buoyant mass spectrometry and IR absorption spectroscopy are possible on liquid samples and micron sized suspended particles (e.g. single cells). Measurements are based on changes in the resonant behavior...... technologies and pre-concentration approaches. A thorough theoretical analysis of the expected sensor responsivity and sensitivity is performed. Predictions made are confirmed by finite element simulations. Using these tools the sensor geometry is optimized for ideal performance in both mass density and IR...... spectroscopy measurements of samples, the size of single yeast cells (≈ 5 μm). A relative frequency shift of 69 ppm/single cell buoyant mass in case of the mass spectroscopy measurements and 40 ppm/μW in case of the IR absorption spectroscopy measurements are calculated and confirmed by FE simulations...

  1. Baclofen pump catheter leakage after migration of the abdominal catheter in a pediatric patient with spasticity. (United States)

    Dastgir, Amer; Ranalli, Nathan J; MacGregor, Theresa L; Aldana, Philipp R


    The authors report an unusual case of intrathecal baclofen withdrawal due to the perforation and subsequent leakage of a baclofen pump catheter in a patient with spastic cerebral palsy. A 15-year-old boy underwent an uncomplicated placement of an intrathecal baclofen pump for the treatment of spasticity due to cerebral palsy. After excellent control of symptoms for 3 years, the patient presented to the emergency department with increasing tremors following a refill of his baclofen pump. Initial evaluation consisted of radiographs of the pump and catheter, which appeared normal, and a successful aspiration of CSF from the pump's side port. A CT dye study revealed a portion of the catheter directly overlying the refill port and extravasation of radiopaque dye into the subfascial pocket anterior to the pump. During subsequent revision surgery, a small puncture hole in the catheter was seen to be leaking the drug. The likely cause of the puncture was an inadvertent perforation of the catheter by a needle during the refilling of the pump. This case report highlights a unique complication in a patient with an intrathecal baclofen pump. Physicians caring for these patients should be aware of this rare yet potential complication in patients presenting with baclofen withdrawal symptoms.

  2. Interventional radiological imaging and treatment of port catheter dysfunctions; Angiografische Diagnostik und interventionelle Therapie von Portdysfunktionen

    Energy Technology Data Exchange (ETDEWEB)

    Kausche, S.; Nagel, S.N.; Teichgraeber, Ulf [Charite Universitaetsmedizin Berlin (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie


    To evaluate the impact of interventional radiological imaging and treatment of central venous port catheter complications. Materials and Methods: In this retrospective analysis 429 port catheter dysfunctions were evaluated in 393 port catheter systems for a total of 389 patients over a period of 10 years. The study included 193 (49.1 %) patients with radiologically implanted port catheter systems and 200 (50.9 %) referred patients with surgically implanted port systems. Port catheter dysfunctions were subdivided into early and late complications as well as into non-thrombotic and thrombotic events. After administration of contrast medium, the port system was visualized using digital subtraction angiography. Data were retrospectively collected from the in-house databases and then analyzed descriptively. Results: 429 contrast media injections via port catheters were performed in 393 port catheter systems. There were 359 (83.7 %) late complications and 70 (16.3 %) early complications. In 299 (69.7 %) cases thrombotic events occurred and 130 (30.3 %) non-thrombotic events were recorded. The most common reason for contrast media injection via port catheter system was port catheter-related thrombosis in 269 (62.7 %) cases. 70 (16.3 %) catheter migrations and 30 (7.0 %) fibrin sheath formations were detected. 18 (4.2 %) port needle malfunctions could be resolved through needle exchange. All 15 (3.5 %) catheter disconnections had to be revised in all cases. Also six port explantations were performed in 6 (1.4 %) catheter fractures. Conclusion: The possibilities of angiographic imaging and interventional radiological correction of port catheter dysfunctions must be exploited fully in order to avoid premature port explantation. (orig.)

  3. Silicon micromachined hollow microneedles for transdermal liquid transport

    NARCIS (Netherlands)

    Gardeniers, Han J.G.E.; Lüttge, Regina; Berenschot, Erwin J.W.; Boer, de Meint J.; Yeshurun, Shuki Y.; Hefetz, Meir; Oever, van 't Ronny; Berg, van den Albert


    This paper presents a novel process for the fabrication of out-of-plane hollow microneedles in silicon. The fabrication method consists of a sequence of deep-reactive ion etching (DRIE), anisotropic wet etching and conformal thin film deposition, and allows needle shapes with different, lithography-


    Pardo, Mariana A; Divers, Stephen


    Long-term or repeated venous access in chelonians is difficult to obtain and manage, but can be critically important for administration of medications and blood sampling in hospitalized patients. Jugular catheterization provides the most rapid and secure route for vascular access, but catheters can be difficult to place, and maintaining catheter patency may be challenging. Long multilumen polyurethane catheters provide flexibility and sampling access, and minimize difficulties, such as catheter displacement, that have been encountered with traditional over-the-needle catheters. We describe placement of 4 Fr. 13-cm polyurethane catheters in three chelonians with the use of a modified Seldinger technique. Venous access was obtained with the use of an over-the-needle catheter, which allowed placement of a 0.018-in.-diameter wire, over which the polyurethane catheter was placed. Indwelling time has ranged between 1 and 4 mo currently. All tortoises were sedated for this procedure. Polyurethane central catheters provide safe, long-term venous access that allows clinicians to perform serial blood sampling as well as intravenous administration of medications, anesthetic agents, and fluids. A jugular catheter can also allow central venous pressure measurement. Utilization of central line catheters was associated with improvements in diagnostic efficiency and therapeutic case management, with minimal risks and complications.

  5. Dosimetric equivalence of non-standard high dose rate (HDR) brachytherapy catheter patterns

    CERN Document Server

    Cunha, J Adam M; Pouliot, Jean


    Purpose: To determine whether alternative HDR prostate brachytherapy catheter patterns can result in improved dose distributions while providing better access and reducing trauma. Methods: Prostate HDR brachytherapy uses a grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. On CT data from ten previously-treated patients new catheters were digitized following three catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a p...

  6. Indwelling urethral catheters in adults


    Calleja, Edward


    This article focuses on indwelling urethral catheters in adults, their indications for the short and long term use, the types of urinary catheters available in Malta, an overview of the basic structure of a catheter, and the complications of urinary catheter insertion and maintenance. An attempt has been made to address in some depth the most common complication of indwelling catheterscatheter associated urinary tract infection in terms of pathophysiology and its management. Simple but cru...

  7. Rectal extrusion of the catheter and air ventriculography following bowel perforation in ventriculo-peritoneal shunt

    Energy Technology Data Exchange (ETDEWEB)

    Arico, M.; Podesta, A.F.; Bianchi, E.; Beluffi, G.; Fiori, P.; Chiari, G.; Pezzotta, S.


    Ventriculo-peritoneal shunt is frequently carried out in infantile hydrocephalus. The peritoneal shunt has a lower morbidity than ventriculo-atrial shunt and severe complications are uncommon. Abdominal complications include intestinal perforation, shunt migration, inguinal hernia, cerebrospinal fluid pseudocysts and hollow viscus perforation. A few cases of catheter extrusion from the rectum, vagina, umbilicus and urethra have been described. We report a new case of intestinal perforation with rectal extrusion of the catheter associated with a ventriculogram.

  8. [The bladder catheter]. (United States)

    Pestalozzi, D M


    The benefit of the transurethral catheter to protect or measure renal function is well accepted. Urethral stricture and infection of the lower urinary tract as the complications should lead to a cautious use of catheters. A careful placement, the choice of the best material and a correct management help to avoid complications. Alternatives are discussed.

  9. A pilot/introducer needle for central vein cannulation. (United States)

    Suzuki, T; Kanazawa, M; Kinefuchi, Y; Fukuyama, H; Takiguchi, M; Yamamoto, M; Abe, K; Okuda, Y


    A kit for safe and easy insertion of a central vein cannula was devised. A small gauge (22 gauge) metal pilot needle was equipped with a Y-shaped hub which had a side-port to accept a small gauge (0.46 mm) Seldinger guide wire. Once the needle reached the vein, guidewire was threaded in through the side-port. There was no need to remove the pilot needle and no need to repeat vein puncture with a larger-bore needle. Three puncture methods were used with the kit: (1) the central approach via the internal jugular vein, (2) the supraclavicular approach via the junction of the internal jugular vein and subclavian vein, and (3) the infraclavicular approach via the subclavian vein. Each method was used on 20 patients, for total of 60 patients, with a high success rate. Less than 3 minutes were required from puncture to catheter insertion. No serious complications were encountered.

  10. 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)


    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.

  11. Effectiveness of a Drill-assisted Intraosseous Catheter versus Manual Intraosseous Catheter by Resident Physicians in a Swine Model

    Directory of Open Access Journals (Sweden)

    Hafner, John William


    Full Text Available Introduction: Our objective was to compare the effectiveness, speed, and complication rate of the traditional manually placed intraosseous (IO catheter to a mechanical drill-assisted IO catheter by emergency medicine (EM resident physicians in a training environment. Methods: Twenty-one EM residents participated in a randomized prospective crossover experiment placing 2 intraosseous needles (Cook® Intraosseous Needle, Cook Medical, Bloomington, IN; and EZ-IO® Infusion System, Vidacare, San Antonio, TX. IO needles were placed in anesthetized mixed breed swine (mass range: 25 kg to 27.2 kg. The order of IO placement and puncture location (proximal tibia or distal femur were randomly assigned. IO placement time was recorded from skin puncture until the operator felt they had achieved successful placement. We used 3 verification criteria: aspiration of marrow blood, easy infusion of 10 mL saline mixed with methylene blue, and lack of stained soft tissue extravasation. Successful placement was defined as meeting 2 out of the 3 predetermined criteria. We surveyed participants regarding previous IO experience, device preferences, and comfort levels using multiple choice, Likert scale, and visual analog scale (VAS questions. IO completion times, VAS, and mean Likert scales were compared using Student’s t-test and success rates were compared using Fisher’s exact test with p<0.05 considered significant.Results: Drill-assisted IO needle placement was faster than manually placed IO needle placement (3.66 vs. 33.57 seconds; p=0.01. Success rates were 100% with the drill-assisted IO needle and 76.2% with the manual IO needle (p=0.04. The most common complication of the manual IO insertion was a bent needle (33.3% of attempts. Participants surveyed preferred the drill-assisted IO insertion more than the manual IO insertion (p<0.0001 and felt the drill-assisted IO was easier to place (p<0.0001.Conclusion: In an experimental swine model, drill-assisted IO

  12. Dedicated radial ventriculography pigtail catheter

    Energy Technology Data Exchange (ETDEWEB)

    Vidovich, Mladen I., E-mail:


    A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

  13. Needle biopsy of histoplasmosis

    Energy Technology Data Exchange (ETDEWEB)

    Sinner, W.N.


    A case of histoplasmosis, simulating a bronchogenic carcinoma, was needle biopsied. Histoplasma capsulatum organisms were found in great numbers. Needle biopsy established an accurate diagnosis making an exploratory thoracotomy unnecessary and preventing the patient from an already planned lobectomy. Specific treatment with Amphotericin B healed the lesion.

  14. Precessing Ferromagnetic Needle Magnetometer. (United States)

    Jackson Kimball, Derek F; Sushkov, Alexander O; Budker, Dmitry


    A ferromagnetic needle is predicted to precess about the magnetic field axis at a Larmor frequency Ω under conditions where its intrinsic spin dominates over its rotational angular momentum, Nℏ≫IΩ (I is the moment of inertia of the needle about the precession axis and N is the number of polarized spins in the needle). In this regime the needle behaves as a gyroscope with spin Nℏ maintained along the easy axis of the needle by the crystalline and shape anisotropy. A precessing ferromagnetic needle is a correlated system of N spins which can be used to measure magnetic fields for long times. In principle, by taking advantage of rapid averaging of quantum uncertainty, the sensitivity of a precessing needle magnetometer can far surpass that of magnetometers based on spin precession of atoms in the gas phase. Under conditions where noise from coupling to the environment is subdominant, the scaling with measurement time t of the quantum- and detection-limited magnetometric sensitivity is t^{-3/2}. The phenomenon of ferromagnetic needle precession may be of particular interest for precision measurements testing fundamental physics.

  15. Hollow dimension of modules

    Institute of Scientific and Technical Information of China (English)


    In this paper, we are interested in the following general question: Given a module Mwhich has finite hollow dimension and which has a finite collection of submodules Ki (1≤i≤n) such that M=K1+... +Kn, can we find an expression for the hollow dimension of Min terms of hollow dimensions of modules built up in some way from K1 Kn? We prove the following theorem:Let Mbe an amply supplemented module having finite hollow dimension and let Ki (1≤i≤n) be a finite collection of submodules of Msuch that M=K1+...+Kn. Then the hollow dimension h(M) of Mis the sum of the hollow dimensions of Ki (1≤i≤n) ifand only if Ki is a supplement of K1+...+Ki-1+Ki+1+...+Kn in Mfor each 1≤i≤n.

  16. Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, J. A. M.; Hsu, I-C.; Pouliot, J. [University of California, San Francisco, California 94115 (United States)


    Purpose: To determine whether alternative high dose rate prostate brachytherapy catheter patterns can result in similar or improved dose distributions while providing better access and reducing trauma. Materials and Methods: Standard prostate cancer high dose rate brachytherapy uses a regular grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. This study used CT datasets with 3 mm slice spacing from ten previously treated patients and digitized new catheters following three hypothetical catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a plan must fulfill the RTOG-0321 dose criteria for target dose coverage (V{sub 100}{sup Prostate}>90%) and organ-at-risk dose sparing (V{sub 75}{sup Bladder}<1 cc, V{sub 75}{sup Rectum}<1 cc, V{sub 125}{sup Urethra}<<1 cc). Results: The three nonstandard catheter patterns used 16 nonparallel, straight divergent catheters, with entry points in the perineum. Thirty plans from ten patients with prostate sizes ranging from 26 to 89 cc were optimized. All nonstandard patterns fulfilled the RTOG criteria when the clinical plan did. In some cases, the dose distribution was improved by better sparing the organs-at-risk. Conclusion: Alternative catheter patterns can provide the physician with additional ways to treat patients previously considered unsuited for brachytherapy treatment (pubic arch interference) and facilitate robotic guidance of


    Institute of Scientific and Technical Information of China (English)

    MA Bin; GAN Zhiyin; LIU Sheng


    Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means-micro needle array based on micro electro-mechanical system (MEMS) technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching (DRIE), anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing.Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.


    Directory of Open Access Journals (Sweden)

    Anacilda Oliveira Vieira


    Full Text Available Introduction: The PICC (peripherally inserted central catheter is a long flexible catheter which is inserted through a peripheral vein, progresses through a needle introducer until the final portion of the vena cava, acquiring characteristics of a central catheter. Objective: To point out the main theoretical and scientific ideas that demonstrate the reliability, competence and ability of nurses to perform the PICC. Methodology: Systematic review of articles, which were found by searching the database scientific journals and bibliographies area. Results: The success of integration depends on the patient assessment and choice of venous access where the catheter will be positioned, and its tip should be in the middle third of the superior vena cava, or the middle third of the inferior vena cava. In neonates, which are used more frequently, proper positioning of the catheter is through nursing care in making the dressing, and the first 24 hours it should be compressive. Ideally, the PICC remains in the vein for periods longer than seven days or until the end of treatment, thus decreasing invasive procedures. Conclusion: According to the Federal Board of Nursing (COFEN, it is lawful for the insertion of PICC nurses, provided it has undergone professional training.

  19. Central venous catheter - dressing change (United States)

    ... during cancer treatment Bone marrow transplant - discharge Central venous catheter - flushing Peripherally inserted central catheter - flushing Sterile technique Surgical wound care - open Review Date 9/17/2016 Updated by: ...

  20. Needle breakage: incidence and prevention. (United States)

    Malamed, Stanley F; Reed, Kenneth; Poorsattar, Susan


    Since the introduction of nonreusable, stainless steel dental local anesthetic needles, needle breakage has become an extremely rare complication of dental local anesthetic injections. But although rare, dental needle breakage can, and does, occur. Review of the literature and personal experience brings into focus several commonalities which, when avoided, can minimize the risk of needle breakage with the fragment being retained from occurring.

  1. Central venous catheter insertion problem solving using intravenous catheter: technical communication

    Directory of Open Access Journals (Sweden)

    Alemohammad M


    Full Text Available Insertion of central venous catheter is an accepted method for hemodynamic monitor-ring, drug and fluid administration, intravenous access, hemodialysis and applying cardiac pace-maker in hospitalized patients. This procedure can be associated with severe complications. The aim of this article is to provide a practical approach to prevent catheter malposition in states that the guide wire will not pass freely.During central venous insertion in internal jugular vein using modified seldinger technique, when after venous insertion, the passage of the guide wire shows difficulties and don’t pass freely, insertion of an intravenous cannula over the wire and re-insertion of the wire can help to prevent malposition of the wire and the catheter. Use of an intravenous cannula over the guide, in situations that the guide wire cannot pass freely among the needle inserted in internal jugular vein, and re-insertion of the guide can probably prevent or reduce the tissue or vascular trauma and the associated complica-tions. This simple maneuver can be helpful in difficult cases especially in cardiac surgery patients who receive high dose heparin and it is necessary to avoid traumatize-tion of carotid artery.

  2. Rapid needle-out patient-rollover approach after cone beam CT-guided lung biopsy: effect on pneumothorax rate in 1,191 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Im [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Sang Min [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of)


    To investigate the effect of rapid needle-out patient-rollover approach on the incidence of pneumothorax and drainage catheter placement due to pneumothorax in C-arm Cone-beam CT (CBCT)-guided percutaneous transthoracic needle biopsy (PTNB) of lung lesions. From May 2011 to December 2012, 1227 PTNBs were performed in 1191 patients with a 17-gauge coaxial needle. 617 biopsies were performed without (conventional-group) and 610 with rapid-rollover approach (rapid-rollover-group). Overall pneumothorax rates and incidences of pneumothorax requiring drainage catheter placement were compared between two groups. There were no significant differences in overall pneumothorax rates between conventional and rapid-rollover groups (19.8 % vs. 23.1 %, p = 0.164). However, pneumothorax rate requiring drainage catheter placement was significantly lower in rapid-rollover-group (1.6 %) than conventional-group (4.2 %) (p = 0.010). Multivariate analysis revealed male, age > 60, bulla crossed, fissure crossed, pleura to target distance > 1.3 cm, emphysema along needle tract, and pleural punctures ≥ 2 were significant risk factors of pneumothorax (p < 0.05). Regarding pneumothorax requiring drainage catheter placement, fissure crossed, bulla crossed, and emphysema along needle tract were significant risk factors (p < 0.05), whereas rapid-rollover approach was an independent protective factor (p = 0.002). The rapid needle-out patient-rollover approach significantly reduced the rate of pneumothorax requiring drainage catheter placement after CBCT-guided PTNB. (orig.)

  3. Use of ultrasound to facilitate femoral nerve block with stimulating catheter

    Institute of Scientific and Technical Information of China (English)

    LI Min; XU Ting; HAN Wen-yong; WANG Xue-dong; JIA Dong-lin; GUO Xiang-yang


    Background The adjunction of ultrasound to nerve stimulation has been proven to improve single-injection peripheral nerve block quality. However, few reports have been published determining whether ultrasound can facilitate continuous nerve blocks. In this study, we tested the hypothesis that the addition of ultrasound to nerve stimulation facilitates femoral nerve blocks with a stimulating catheter.Methods In this prospective randomized study, patients receiving continuous femoral nerve blocks for total knee replacement were randomly assigned to either the ultrasound guidance combined with stimulating catheter group (USNS group; n=60) or the stimulating catheter alone group (NS group; n=60). The primary end point was the procedure time (defined as the time from first needle contact with the skin until correct catheter placement). The numbers of needle passes and catheter insertions, onset and quality of femoral nerve blocks, postoperative pain score, and early knee function were also recorded.Results The procedure time was significantly less in the USNS group than in the NS group (9.0 (6.0-22.8) minutes vs.13.5 (6.0-35.9) minutes, P=0.024). The numbers of needle passes and catheter insertions were also significantly less in the USNS group. A greater complete block rate was achieved at 30 minutes in the USNS group (63.3% vs. 38.3%;P=0.010). The postoperative pain score, the number of patients who required bolus local anesthetic and intravenous patient-controlled analgesia, and knee flexion on the second postoperative day were not significantly different between the two groups of patients.Conclusions Ultrasound-assisted placement of a stimulating catheter for femoral nerve blocks decreases the time necessary to perform the block compared with just the nerve-stimulating technique. In addition, a more complete blockade is achieved using the ultrasound-assisted technique.

  4. Development of Needle Insertion Manipulator for Central Venous Catheterization (United States)

    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.

  5. Application of enteral nutritional support by needle catheter jejunostomy feeding tube during postoperative adjuvant chemotherapy of staged gastric cancer%延期留置空肠造口管间断肠内营养在进展期胃癌术后辅助化疗中的应用评价

    Institute of Scientific and Technical Information of China (English)

    苏国森; 湛建伟


    Objegtive To study the feasibility and clinical effects of enteral nutrition by needle catheter jejunostomy(NCJ)tube in the postoperative adjuvant chemotherapy for patients of staged gastric cancer.Methods Eighty-two patients with staged gastric cancer underwent radical gastrectomy and going to receive chemotherapy were randomly divided into group A(41 cases)and group B(41 cases).All of the patients had been NCJ.Group A received enteral nutrition through the tube during chemotherapy,and group B had been given general diet.A series of parameters were measured post-chemotherapy.And the gastrointestinal complications were carefully observed.Results In post-chemotherapy,the level of hemoglobin,albumin,prealbumin,interleukin-2,natural killer cell activities and CD3+,CDd4+,CD4/CD8 in group A[(106.9±12.0)g/L,(26.2±1.4)g/L,(202.9±32.2)mg/L,(11.9±2.1)μg/L,(21.3±5.2)%,(62.9±3.3)%,(26.1±4.7)%,1.1±0.2]were significantly higher than those in group B(P<0.05 or<0.01).The incidences of vomiting in group A(4.9%,2/41)was significantly lower than that in group B (26.8%,11/41)(P<0.05).The average intake in group A[(1312±114)ml]was significantly more than that in group B[(76.5±186)ml](P<0.05).No severe enteral nutrition related complications occurred in group A.Conclusions It is safe and feasible to enteral nutrition supported by NCJ tube in chemotherapy for patients of staged gastric cancer.It can improve the nutrition status and immune function in the given patients.%目的 研究延期留置空肠造口管间断肠内营养在进展期胃癌术后辅助化疗中应用的可行性及疗效.方法 将进展期胃癌术后行辅助化疗的82例患者按机械抽样法随机分成A、B两组,每组各41例.均于术中放置空肠造口管,A组延期留置空肠造口管至化疗6个疗程结束,每个化疗疗程经空肠造口管给予肠内营养液;B组于化疗前拔除空肠造口管,每个化疗疗程给予普通饮食.比较化疗后两组营养及免疫指

  6. Central Venous Catheter Intravascular Malpositioning: Causes, Prevention, Diagnosis, and Correction. (United States)

    Roldan, Carlos J; Paniagua, Linda


    Despite the level of skill of the operator and the use of ultrasound guidance, central venous catheter (CVC) placement can result in CVC malpositioning, an unintended placement of the catheter tip in an inadequate vessel. CVC malpositioning is not a complication of central line insertion; however, undiagnosed CVC malpositioning can be associated with significant morbidity and mortality. The objectives of this review were to describe factors associated with intravascular malpositioning of CVCs inserted via the neck and chest and to offer ways of preventing, identifying, and correcting such malpositioning. A literature search of PubMed, Cochrane Library, and MD Consult was performed in June 2014. By searching for "Central line malposition" and then for "Central venous catheters intravascular malposition," we found 178 articles written in English. Of those, we found that 39 were relevant to our objectives and included them in our review. According to those articles, intravascular CVC malpositioning is associated with the presence of congenital and acquired anatomical variants, catheter insertion in left thoracic venous system, inappropriate bevel orientation upon needle insertion, and patient's body habitus variants. Although plain chest radiography is the standard imaging modality for confirming catheter tip location, signs and symptoms of CVC malpositioning even in presence of normal or inconclusive conventional radiography findings should prompt the use of additional diagnostic methods to confirm or rule out CVC malpositioning. With very few exceptions, the recommendation in cases of intravascular CVC malpositioning is to remove and relocate the catheter. Knowing the mechanisms of CVC malpositioning and how to prevent, identify, and correct CVC malpositioning could decrease harm to patients with this condition.

  7. Central Venous Catheter Intravascular Malpositioning: Causes, Prevention, Diagnosis, and Correction

    Directory of Open Access Journals (Sweden)

    Carlos J. Roldan


    Full Text Available Despite the level of skill of the operator and the use of ultrasound guidance, central venous catheter (CVC placement can result in CVC malpositioning, an unintended placement of the catheter tip in an inadequate vessel. CVC malpositioning is not a complication of central line insertion; however, undiagnosed CVC malpositioning can be associated with significant morbidity and mortality. The objectives of this review were to describe factors associated with intravascular malpositioning of CVCs inserted via the neck and chest and to offer ways of preventing, identifying, and correcting such malpositioning. A literature search of PubMed, Cochrane Library, and MD Consult was performed in June 2014. By searching for “Central line malposition” and then for “Central venous catheters intravascular malposition,” we found 178 articles written in English. Of those, we found that 39 were relevant to our objectives and included them in our review. According to those articles, intravascular CVC malpositioning is associated with the presence of congenital and acquired anatomical variants, catheter insertion in left thoracic venous system, inappropriate bevel orientation upon needle insertion, and patient’s body habitus variants. Although plain chest radiography is the standard imaging modality for confirming catheter tip location, signs and symptoms of CVC malpositioning even in presence of normal or inconclusive conventional radiography findings should prompt the use of additional diagnostic methods to confirm or rule out CVC malpositioning. With very few exceptions, the recommendation in cases of intravascular CVC malpositioning is to remove and relocate the catheter. Knowing the mechanisms of CVC malpositioning and how to prevent, identify, and correct CVC malpositioning could decrease harm to patients with this condition.

  8. Hollow-Fiber Clinostat (United States)

    Rhodes, Percy H.; Miller, Teresa Y.; Snyder, Robert S.


    Hollow-fiber clinostat, is bioreactor used to study growth and other behavior of cells in simulated microgravity. Cells under study contained in porous hollow fiber immersed in culture medium inside vessel. Bores in hollow fiber allow exchange of gases, nutrients, and metabolic waste products between living cells and external culture media. Hollow fiber lies on axis of vessel, rotated by motor equipped with torque and speed controls. Desired temperature maintained by operating clinostat in standard tissue-culture incubator. Axis of rotation made horizontal or vertical. Designed for use with conventional methods of sterilization and sanitation to prevent contamination of specimen. Also designed for asepsis in assembly, injection of specimen, and exchange of medium.

  9. Engineering Stable Hollow Capsules

    Institute of Scientific and Technical Information of China (English)


    @@ Scientists at the CAS Institute of Chemistry have been succeeded in fabricating stable hollow capsules by extending covalent layer-by-layer self-assembly(CSA)technique from 2-dimensional to 3-dimensional systems.

  10. Preprocedural ultrasound examination versus manual palpation for thoracic epidural catheter insertion (United States)

    Hasanin, Ahmed M.; Mokhtar, Ali M.; Amin, Shereen M.; Sayed, Ahmed A.


    Background and Aims: Ultrasound imaging before neuraxial blocks was reported to improve the ease of insertion and minimize the traumatic trials. However, the data about the use of ultrasound in thoracic epidural block are scanty. In this study, pre-insertion ultrasound scanning was compared to traditional manual palpation technique for insertion of the thoracic epidural catheter in abdominal operations. Subjects and Methods: Forty-eight patients scheduled to midline laparotomy under combined general anesthesia with thoracic epidural analgesia were included in the study. Patients were divided into two groups with regard to technique of epidural catheter insertion; ultrasound group (done ultrasound screening to determine the needle insertion point, angle of insertion, and depth of epidural space) and manual palpation group (used the traditional manual palpation technique). Number of puncture attempts, number of puncture levels, and number of needle redirection attempts were reported. Time of catheter insertion and complications were also reported in both groups. Results: Ultrasound group showed lower number of puncture attempts (1 [1, 1.25] vs. 1.5 [1, 2.75], P = 0.008), puncture levels (1 (1, 1) vs. 1 [1, 2], P = 0.002), and needle redirection attempts (0 [0, 2.25] vs. 3.5 [2, 5], P = 0.00). Ultrasound-guided group showed shorter time for catheter insertion compared to manual palpation group (140 ± 24 s vs. 213 ± 71 s P = 0.00). Conclusion: Preprocedural ultrasound imaging increased the incidence of first pass success in thoracic epidural catheter insertion and reduced the catheter insertion time compared to manual palpation method. PMID:28217056

  11. Treatment feasibility study of osteoporosis using minimal invasive laser needle system (United States)

    Kang, Dongyeon; Ko, Chang-Yong; Ryu, Yeon-Hang; Park, Sunwook; Kim, Han-Sung; Jung, Byungjo


    Although the mechanism of laser stimulation effect in bone has not completely understood, laser stimulation is recommended in the treatment of osteoporosis due to positive treatment efficacy. In this study, a minimal invasive laser needle system (MILNS) was developed using a fine hollow needle in order to stimulate directly bone site by guiding an optical fiber. In order to evaluate the MILNS as a treatment method, in-vivo animal experiment study was performed using osteopenic mice. Twelve virginal ICR mice were employed and divided two groups: SHAM-group and LASERgroup. SHARM-group was stimulated by only fine hollow needle and LASER-group by fine hollow needle combined with laser stimulation. All mice were served in-vivo micro-CT images before and after treatment. Three dimensional (3D) structural parameters and vBMD (volume bone mineral density, g/cm3) in the trabecular bone were measured. After 2 weeks of stimulation, the vBMD, BV/TV, Tb.Th and Tb.N in LASER-group were significantly higher than those in SHAM-group (pprevent the bone loss and maintains the bone mineral density of osteopenic mice.

  12. Hollow-Core Fiber Lamp (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)


    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  13. Lumbar epidural catheter placement in the presence of low back tattoos: a review of the safety concerns. (United States)

    Welliver, Dawn; Welliver, Mark; Carroll, Tammy; James, Peggy


    Current fashion in body art includes low back tattoos of varying designs and colors, a trend that presents unique concerns for anesthesia providers. Does the placement of epidural catheters risk the introduction of tattoo pigment dyes into the epidural space through the process of coring? Are there specific risks associated with tattoo dyes and epidural needle placement? We performed a comprehensive review of the literature using multiple search databases with the intent to form guidelines for practice using a level of evidence taxonomy. The available evidence does not identify any specific risks associated with epidural catheter placement through low back tattoos, although tissue coring with tissue transport to deeper sites has been confirmed. Continued investigation is necessary before comprehensive practice guidelines regarding the practice of placing epidural needles and catheters through lumbar tattoos can be developed. We suggest avoidance of piercing tattoos when performing epidural punctures until there is sound evidence of short-term and long-term safety.

  14. The Terry Biopsy Needle (United States)

    Bond, Alan F.; Murphy, Fergus A.; Nanson, Eric M.


    Six illustrative cases are reported to demonstrate the versatility of the Terry biopsy needle as a useful instrument for obtaining satisfactory biopsy specimens from the liver and from other tissues as well. The apparatus and method of use are described and illustrated. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6aFig. 6bFig. 7Fig. 8Fig. 9Fig. 10Fig. 11 PMID:13968726

  15. Comparison of complications between pediatric peripherally inserted central catheter placement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Niloy; Lungren, Matthew P. [Lucile Packard Children' s Hospital Stanford, Department of Radiology, Palo Alto, CA (United States); Patel, Manish N.; Racadio, John M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)


    Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique. To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center. We retrospectively reviewed all PICC placements at a single institution over a 4-year period. We reviewed patient records for demographic data, PICC placement technique, catheter size and number of lumens, and the incidence of complications (i.e. multiple attempted puncture sites, phlebitis and vessel thrombosis). We analyzed complication rates between two placement techniques using a chi-square test. We identified 8,816 successful PICC placements, 4,749 (53.9%) in males and 4,067 (46.1%) in females. The average age of the patients for which a line was placed was 5.6 years (range 1 day to 45 years). A direct sheathed needle puncture technique was used in 8,362 (94.9%) placements and a modified Seldinger technique was used in 454 (5.1%). Complications occurred in 312 (3.7%) of direct sheathed needle puncture placements versus 17 (3.7%) of modified Seldinger placements (P = 0.99). Multiple puncture sites were required in 175 (2.1%) attempted direct sheathed needle puncture placements compared with 8 (1.7%) attempted modified Seldinger placements (P = 0.63). Phlebitis occurred in 94 (1.1%) direct sheathed needle puncture lines versus 5 (1.1%) modified Seldinger placed lines (P = 0.96). Vessel thrombosis occurred in 43 (0.5%) direct sheathed needle puncture lines versus 4 (0.9%) modified Seldinger placed lines (P = 0.30). The direct peel-away sheathed needle vessel puncture technique and the modified Seldinger technique used to place PICC lines in children have similar complication rates. (orig.)

  16. Creation of transcatheter aortopulmonary and cavopulmonary shunts using magnetic catheters: feasibility study in swine. (United States)

    Levi, Daniel S; Danon, Saar; Gordon, Brent; Virdone, Nicky; Vinuela, Fernando; Shah, Sanjay; Carman, Greg; Moore, John W


    Surgical shunts are the basic form of palliation for many types of congenital heart disease. The Glenn shunt (superior cavopulmonary connection) and central shunt (aortopulmonary connection) represent surgical interventions that could potentially be accomplished by transcatheter techniques. We sought to investigate the efficacy of using neodymium iron boron (NdFeB) magnetic catheters to create transcatheter cavopulmonary and aortopulmonary shunts. NdFeB magnets were machined and integrated into catheters. "Target" catheters were placed in the pulmonary arteries (PAs), and radiofrequency "perforation" catheters were placed in either the descending aorta (DAo) for central shunts or the superior vena cava (SVC) for Glenn shunts. The magnet technique or "balloon target" method was used to pass wires from the DAo or the SVC into the PA. Aortopulmonary and cavopulmonary connections were then created using Atrium iCAST covered stents. Magnet catheters were used to perforate the left pulmonary artery from the DAo, thereby establishing a transcatheter central shunt. Given the orientation of the vasculature, magnetic catheters could not be used for SVC-to-PA connections; however, perforation from the SVC to the right pulmonary artery was accomplished with a trans-septal needle and balloon target. Transcatheter Glenn or central shunts were successfully created in four swine.

  17. From the Cover: Microfabricated needles for transdermal delivery of macromolecules and nanoparticles: Fabrication methods and transport studies (United States)

    McAllister, Devin V.; Wang, Ping M.; Davis, Shawn P.; Park, Jung-Hwan; Canatella, Paul J.; Allen, Mark G.; Prausnitz, Mark R.


    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

  18. Hydrodynamics of catheter biofilm formation

    CERN Document Server

    Sotolongo-Costa, Oscar; Rodriguez-Perez, Daniel; Martinez-Escobar, Sergio; Fernandez-Barbero, Antonio


    A hydrodynamic model is proposed to describe one of the most critical problems in intensive medical care units: the formation of biofilms inside central venous catheters. The incorporation of approximate solutions for the flow-limited diffusion equation leads to the conclusion that biofilms grow on the internal catheter wall due to the counter-stream diffusion of blood through a very thin layer close to the wall. This biological deposition is the first necessary step for the subsequent bacteria colonization.

  19. Emergency percutaneous needle decompression for tension pneumoperitoneum

    Directory of Open Access Journals (Sweden)

    Körner Markus


    Full Text Available Abstract Background Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic. Methods This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension. Results Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs, between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs. Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion, bridging the time to the start of the operation. Conclusions Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no

  20. New puncture needle (Seldinger technique) for easy antegrade catheterization of the superficial femoral artery

    Energy Technology Data Exchange (ETDEWEB)

    Saltzmann, J.; Probst, P.


    Mainly for anatomical reasons a guide-wire or a catheter has a tendency to turn into the deep femoral artery during antegrade catheterization of the lower limb. To overcome this problem a curved puncture needle has been designed which allows positioning of the guide-wire in an anterior direction. Antegrade catheterization of the superficial femoral artery was achieved in 25 patients without lengthy manipulations or complications. With this technique the rate of complications at antegrade catheterization will probably be reduced.

  1. Implantation of peritoneal catheters by laparotomy: nephrologists obtained similar results to general surgeons

    Directory of Open Access Journals (Sweden)

    Restrepo CA


    Full Text Available Cesar A Restrepo, Carlos Alberto Buitrago, Cielo Holguin Division of Nephrology, Department of Health Sciences, Caldas University, Caldas, ColombiaPurpose: To analyze the complications and costs of minilaparotomies performed by a nephrologist (group A compared with conventional laparotomies performed by a surgeon (group B for peritoneal catheter implantation.Setting: Two university hospitals (Santa Sofia and Caldas in Manizales, Caldas, Colombia.Methods: The study included stage 5 chronic kidney disease patients, with indication of renal replacement therapy, who were candidates for peritoneal dialysis and gave informed consent for a peritoneal catheter implant. Minilaparotomies were performed by a nephrologist in a minor surgery room under local anesthesia. Conventional laparotomies were performed by a surgeon in an operating room under general anesthesia.Results: Two nephrologists inserted 157 peritoneal catheters, and seven general surgeons inserted 185 peritoneal catheters. The groups had similar characteristics: the mean age was 55 years, 49.5% were men, and the primary diagnoses were diabetic nephropathy, hypertensive nephropathy, and unknown etiology. The implant was successful for 98.09% of group A and 99.46% of group B. There was no procedure-related mortality. The most frequent complications in the first 30 days postsurgery in group A versus group B, respectively, were: peritonitis (6.37% versus 3.78%, exit-site infection (3.82% versus 2.16%, tunnel infection (0% versus 0.54%, catheter entrapment by omentum (1.27% versus 3.24%, peritoneal effluent spillover (1.91% versus 2.16%, draining failure (4.46% versus 6.49%, hematoma (0% versus 1.08%, catheter migration with kinking (3.18% versus 2.70%, hemoperitoneum (1.27% versus 0%, and hollow viscera accidental puncture (1.91% versus 0.54%. There were no statistically significant differences in the number of complications between groups. In 2013, the cost of a surgeon-implanted peritoneal

  2. have a hollow leg

    Institute of Scientific and Technical Information of China (English)



    英语对话 A:We must prevent our family members from getting involved with drugs, really. B:That’s a sure thing.We must make sure that they never involve them- selves with that. A:By the way,does your husband drink a lot? B:Yeah.That’s the only thing that keeps worrying me.And he often boasts that he has a hollow leg and nobody can drink him under the ta- ble.

  3. Smart needles for percutaneous interventions

    NARCIS (Netherlands)

    Henken, K.R.


    The development of advanced needles for diagnostic and therapeutic purposes such as ablation and brachytherapy in the liver has offered minimally invasive therapies to patients that were previously untreatable. This thesis focuses on accurate placement of such needles guided by magnetic resonance im

  4. Compensation for Unconstrained Catheter Shaft Motion in Cardiac Catheters (United States)

    Degirmenci, Alperen; Loschak, Paul M.; Tschabrunn, Cory M.; Anter, Elad; Howe, Robert D.


    Cardiac catheterization with ultrasound (US) imaging catheters provides real time US imaging from within the heart, but manually navigating a four degree of freedom (DOF) imaging catheter is difficult and requires extensive training. Existing work has demonstrated robotic catheter steering in constrained bench top environments. Closed-loop control in an unconstrained setting, such as patient vasculature, remains a significant challenge due to friction, backlash, and physiological disturbances. In this paper we present a new method for closed-loop control of the catheter tip that can accurately and robustly steer 4-DOF cardiac catheters and other flexible manipulators despite these effects. The performance of the system is demonstrated in a vasculature phantom and an in vivo porcine animal model. During bench top studies the robotic system converged to the desired US imager pose with sub-millimeter and sub-degree-level accuracy. During animal trials the system achieved 2.0 mm and 0.65° accuracy. Accurate and robust robotic navigation of flexible manipulators will enable enhanced visualization and treatment during procedures. PMID:27525170

  5. Bacteriological Profile of Epidural Catheters

    Directory of Open Access Journals (Sweden)

    B. M. Sahay, Sanjot Dahake, D. K Mendiratta*,Vijayshree Deotale*,B. Premendran, P.S.Dhande, Pratibha Narang*


    Full Text Available The bacteriological profile of epidural catheters was studied in 88 patients. Skin swabs before catheterizationand before removal of catheter with their controls were cultured in TSB Medium. The catheter hub, theportion at the skin puncture site and at the tip were cultured in TSB Medium. The 1cm of the catheter bitjust before the tip was cultured in TGB medium for anaerobes.Both, the skin controls swabs and theanaerobic culture, were negative. From the remaining, 56 positive cultures were obtained. Staphylococcusepidermidis was the predominant organism in 52% followed by staphylococcus aureus 25%. The remaining23% was shared by Acinetobacter, Pseudomonas, Klebsiella, and E. coli. All the positive cultures fromskin prior to epidural catheterization had turned sterile by 48 hours, indicating continued bactericidal actionof the disinfectant. The likely source of positive skin cultures at 48 hours is hair follicles.The catheter tipculture was positive in 9 specimen, none of which resulted in the formation of epidural abscess. In 3 casesthe cultures of skin puncture site and the tip were identical indicating tracking-in of the organisms.

  6. Mercury - the hollow planet (United States)

    Rothery, D. A.


    Mercury is turning out to be a planet characterized by various kinds of endogenous hole (discounting impact craters), which are compared here. These include volcanic vents and collapse features on horizontal scales of tens of km, and smaller scale depressions ('hollows') associated with bright crater-floor deposits (BCFD). The BCFD hollows are tens of metres deep and kilometres or less across and are characteristically flat-floored, with steep, scalloped walls. Their form suggests that they most likely result from removal of surface material by some kind of mass-wasting process, probably associated with volume-loss caused by removal (via sublimation?) of a volatile component. These do not appear to be primarily a result of undermining. Determining the composition of the high-albedo bluish surface coating in BCFDs will be a key goal for BepiColombo instruments such as MIXS (Mercury Imaging Xray Spectrometer). In contrast, collapse features are non-circular rimless pits, typically on crater floors (pit-floor craters), whose morphology suggests collapse into void spaces left by magma withdrawal. This could be by drainage of either erupted lava (or impact melt) or of shallowly-intruded magma. Unlike the much smaller-scale BCFD hollows, these 'collapse pit' features tend to lack extensive flat floors and instead tend to be close to triangular in cross-section with inward slopes near to the critical angle of repose. The different scale and morphology of BCFD hollows and collapse pits argues for quite different modes of origin. However, BCFD hollows adjacent to and within the collapse pit inside Scarlatti crater suggest that the volatile material whose loss was responsible for the growth of the hollows may have been emplaced in association with the magma whose drainage caused the main collapse. Another kind of volcanic collapse can be seen within a 25 km-wide volcanic vent outside the southern rim of the Caloris basin (22.5° N, 146.1° E), on a 28 m/pixel MDIS NAC image

  7. Catheter-based photoacoustic endoscope (United States)

    Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.


    We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique's benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument's flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system.

  8. Hollow Polyimide Microspheres (United States)

    Weiser, Erik S. (Inventor); St.Clair, Terry L. (Inventor); Echigo, Yoshiaki (Inventor); Kaneshiro, Hisayasu (Inventor)


    A shaped article composed of an aromatic polyimide has a hollow, essentially spherical structure and a particle size of about 100 to about 1500 micrometers, a density of about 1 to about 6 pounds/cubic foot and a volume change of 1 to about 20% by a pressure treatment of 30 psi for 10 minutes at room temperature. A syntactic foam, made of a multiplicity of the shaped articles which are bonded together by a matrix resin to form an integral composite structure, has a density of about 3 to about 30 pounds/cubic feet and a compression strength of about 100 to about 1400 pounds/sq inch.

  9. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John


    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  10. Changing the needle for lumbar punctures

    DEFF Research Database (Denmark)

    Engedal, Thorbjørn Søndergaard; Ording, H.; Vilholm, O. J.


    describes the process of changing the needle in an outpatient clinic of a Danish neurology department. Methods: Prospective interventional trial. Phase 1: 22 G cutting needle. Phase 2: 25 G non-cutting needle. Practical usability of each needle was recorded during the procedure, while the rate of PDPH...

  11. 21 CFR 880.5580 - Acupuncture needle. (United States)


    ... 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....

  12. Missing needle during episiotomy repair

    Directory of Open Access Journals (Sweden)

    Joydeb Roychowdhury


    Full Text Available Breakage and missing of the episiotomy needle is not uncommon occurrence at the hands of the junior doctors. Retrieving it from deeper tissue planes following its migration can be a challenging task.

  13. Hemodialysis Tunneled Catheter-Related Infections (United States)

    Miller, Lisa M.; Clark, Edward; Dipchand, Christine; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Lok, Charmaine; Luscombe, Rick; Moist, Louise; Oliver, Matthew; MacRae, Jennifer


    Catheter-related bloodstream infections, exit-site infections, and tunnel infections are common complications related to hemodialysis central venous catheter use. The various definitions of catheter-related infections are reviewed, and various preventive strategies are discussed. Treatment options, for both empiric and definitive infections, including antibiotic locks and systemic antibiotics, are reviewed.

  14. 21 CFR 870.1280 - Steerable catheter. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Steerable catheter. 870.1280 Section 870.1280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1280 Steerable catheter. (a) Identification. A steerable catheter is...

  15. 21 CFR 882.4100 - Ventricular catheter. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular catheter. 882.4100 Section 882.4100...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4100 Ventricular catheter. (a) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for...

  16. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study (United States)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina


    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  17. Effectiveness of different central venous catheters for catheter-related infections: a network meta-analysis. (United States)

    Wang, H; Huang, T; Jing, J; Jin, J; Wang, P; Yang, M; Cui, W; Zheng, Y; Shen, H


    We aimed to compare the effectiveness of various catheters for prevention of catheter-related infection and to evaluate whether specific catheters are superior to others for reducing catheter-related infections. We identified randomised, controlled trials that compared different types of central venous catheter (CVC), evaluating catheter-related infections in a systematic search of articles published from January 1996 to November 2009 via Medline, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. Network meta-analysis with a mixed treatment comparison method using Bayesian Markov Chain Monte Carlo simulation was used to combine direct within-trial, between-treatment comparisons with indirect trial evidence. Forty-eight clinical trials (12 828 CVCs) investigating 10 intervention catheters contributed to the analyses. For prevention of CVC colonisation, adjusted silver iontophoretic catheters (odds ratio: 0.58; 95% confidence interval: 0.33-0.95), chlorhexidine and silver sulfadiazine catheters (0.49; 0.36-0.64), chlorhexidine and silver sulfadiazine blue plus catheters (0.37; 0.17-0.69), minocycline-rifampicin catheters (0.28; 0.17-0.43) and miconazole-rifampicin catheters (0.11; 0.02-0.33) were associated with a significantly lower rate of catheter colonisation compared with standard catheters. For prevention of CRBSI, adjusted heparin-bonded catheters (0.20; 0.06-0.44) and minocycline-rifampicin catheters (0.18; 0.08-0.34) were associated with a significantly lower rate of CRBSI with standard catheters. Rifampicin-based impregnated catheters seem to be better for prevention of catheter-related infection compared with the other catheters.

  18. Mechanical performance of disposable surgical needle holders. (United States)

    Francis, E H; Towler, M A; Moody, F P; McGregor, W; Himel, H N; Rodeheaver, G T; Edlich, R F


    The mechanical performance of disposable Webster surgical needle holders supplied by three different surgical instrument companies was determined by recording the forces (clamping moment) applied by the different needle holder jaws to curved surgical needles. This investigation demonstrated that there was a large variability in the mechanical performance of the disposable needle holders supplied by each surgical instrument company. In addition, the mechanical performance of the disposable needle holder of each surgical instrument company was distinctly different.

  19. Cytometric Catheter for Neurosurgical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Evans III, Boyd Mccutchen [ORNL; Allison, Stephen W [ORNL; Fillmore, Helen [ORNL; Broaddus, William C [ORNL; Dyer, Rachel L [ORNL; Gillies, George [ORNL


    Implantation of neural progenitor cells into the central nervous system has attracted strong interest for treatment of a variety of pathologies. For example, the replacement of dopamine-producing (DA) neural cells in the brain appears promising for the treatment of patients affected by Parkinson's disease. Previous studies of cell-replacement strategies have shown that less than 90% of implanted cells survive longer than 24 - 48 hours following the implantation procedure. However, it is unknown if these cells were viable upon delivery, or if they were affected by other factors such as brain pathology or an immune response. An instrumented cell-delivery catheter has been developed to assist in answering these questions by facilitating quantification and monitoring of the viability of the cells delivered. The catheter uses a fiber optic probe to perform flourescence-based cytometric measurments on cells exiting the port at the catheter tip. The current implementation of this design is on a 3.2 mm diameter catheter with 245 micrometer diameter optical fibers. Results of fluorescence testing data are presented and show that the device can characterize the quantity of cell densities ranging from 60,000 cells/ml to 600,000 cells/ml with a coefficient of determination of 0.93.

  20. Transhepatic venous catheters for hemodialysis

    Directory of Open Access Journals (Sweden)

    Mohamed El Gharib


    Conclusion: Based on our findings, transhepatic hemodialysis catheters have proven to achieve good long-term functionality. A high level of maintenance is required to preserve patency, although this approach provides remarkably durable access for patients who have otherwise exhausted access options.

  1. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc, E-mail: [Département de physique, de génie physique et d’optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de radio-oncologie et Axe Oncologie du Centre de recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Binnekamp, Dirk [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best 5680 DA (Netherlands)


    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  2. Totally implantable catheter embolism: two related cases

    Directory of Open Access Journals (Sweden)

    Rodrigo Chaves Ribeiro

    Full Text Available CONTEXT AND OBJECTIVE: Long-term totally implantable catheters (e.g. Port-a-Cath® are frequently used for long-term venous access in children with cancer. The use of this type of catheter is associated with complications such as infection, extrusion, extravasation and thrombosis. Embolism of catheter fragments is a rare complication, but has potential for morbidity. The aim here was to report on two cases in which embolism of fragments of a long-term totally implantable catheter occurred. DESIGN AND SETTING: Case series study at Hospital do Servidor Público Estadual, São Paulo. METHODS: Retrospective review of catheter embolism in oncological pediatric patients with long-term totally implantable catheters. RESULTS: The first patient was a 3-year-old girl diagnosed with stage IV Wilms' tumor. Treatment was started with the introduction of a totally implantable catheter through the subclavian vein. At the time of removal, it was realized that the catheter had fractured inside the heart. An endovascular procedure was necessary to remove the fragment. The second case was a boy diagnosed with stage II Wilms' tumor at the age of two years. At the time of removal, it was noticed that the catheter had disconnected from the reservoir and an endovascular procedure was also necessary to remove the embolized catheter. CONCLUSION: Embolism of fragments of totally implantable catheters is a rare complication that needs to be recognized even in asymptomatic patients.

  3. Needle-Stick Injury and Medical Students' Knowledge

    Directory of Open Access Journals (Sweden)

    Shahin Gasemi


    Full Text Available Health-care worker's contamination was noticed with discovery of blood-borne pathogens in the late 1980's. The main way of this transmission is via hollow intravascular needles, although other sharp instruments are also important [1]. Sixty blood-borne pathogens have been reported until now which contain 26 kinds of viruses, 18 kinds of bacteria/ rickettsias, 13 kinds of parasites and 3 different fungi. However, Hepatitis B, C and HIV viruses responsible for the majority of occupational transmission [2]. The risk of this transmission in Hepatitis B (30%, Hepatitis C (1.8% and HIV (0.3% depend on patient's viral load and the amount of blood that has been transmitted from patient to health-care worker [3].

  4. Real-Time 3-Dimensional Ultrasound-Assisted Infraclavicular Brachial Plexus Catheter Placement: Implications of a New Technology

    Directory of Open Access Journals (Sweden)

    Steven R. Clendenen


    Full Text Available Background. There are a variety of techniques for targeting placement of an infraclavicular blockade; these include eliciting paresthesias, nerve stimulation, and 2-dimensional (2D ultrasound (US guidance. Current 2D US allows direct visualization of a “flat” image of the advancing needle and neurovascular structures but without the ability to extensively analyze multidimensional data and allow for real-time manipulation. Three-dimensional (3D ultrasonography has gained popularity and usefulness in many clinical specialties such as obstetrics and cardiology. We describe some of the potential clinical applications of 3D US in regional anesthesia. Methods. This case represents an infraclavicular catheter placement facilitated by 3D US, which demonstrates 360-degree spatial relationships of the entire anatomic region. Results. The block needle, peripheral nerve catheter, and local anesthetic diffusion were observed in multiple planes of view without manipulation of the US probe. Conclusion. Advantages of 3D US may include the ability to confirm correct needle and catheter placement prior to the injection of local anesthetic. The spread of local anesthetic along the length of the nerve can be easily observed while manipulating the 3D images in real-time by simply rotating the trackball on the US machine to provide additional information that cannot be identified with 2D US alone.

  5. Untangling of knotted urethral catheters. (United States)

    Sambrook, Andrew J; Todd, Alistair


    Intravesical catheter knotting during micturating cystourethrography is a rare but recognized complication of the procedure. We were able to untangle a knot utilizing a fluoroscopically guided vascular guidewire. Following this success, a small study was performed using a model. Various types of guidewires and techniques were tested for different diameters of knots in order to predict the likelihood of success in this type of situation.

  6. Untangling of knotted urethral catheters

    Energy Technology Data Exchange (ETDEWEB)

    Sambrook, Andrew J. [Aberdeen Royal Infirmary, Department of Radiology, Aberdeen (United Kingdom); Todd, Alistair [Raigmore Hospital, Inverness (United Kingdom)


    Intravesical catheter knotting during micturating cystourethrography is a rare but recognized complication of the procedure. We were able to untangle a knot utilizing a fluoroscopically guided vascular guidewire. Following this success, a small study was performed using a model. Various types of guidewires and techniques were tested for different diameters of knots in order to predict the likelihood of success in this type of situation. (orig.)

  7. Dry needling: a literature review with implications for clinical practice guidelines1 (United States)

    Dunning, James; Butts, Raymond; Mourad, Firas; Young, Ian; Flannagan, Sean; Perreault, Thomas


    Background: Wet needling uses hollow-bore needles to deliver corticosteroids, anesthetics, sclerosants, botulinum toxins, or other agents. In contrast, dry needling requires the insertion of thin monofilament needles, as used in the practice of acupuncture, without the use of injectate into muscles, ligaments, tendons, subcutaneous fascia, and scar tissue. Dry needles may also be inserted in the vicinity of peripheral nerves and/or neurovascular bundles in order to manage a variety of neuromusculoskeletal pain syndromes. Nevertheless, some position statements by several US State Boards of Physical Therapy have narrowly defined dry needling as an ‘intramuscular’ procedure involving the isolated treatment of ‘myofascial trigger points’ (MTrPs). Objectives: To operationalize an appropriate definition for dry needling based on the existing literature and to further investigate the optimal frequency, duration, and intensity of dry needling for both spinal and extremity neuromusculoskeletal conditions. Major findings: According to recent findings in the literature, the needle tip touches, taps, or pricks tiny nerve endings or neural tissue (i.e. ‘sensitive loci’ or ‘nociceptors’) when it is inserted into a MTrP. To date, there is a paucity of high-quality evidence to underpin the use of direct dry needling into MTrPs for the purpose of short and long-term pain and disability reduction in patients with musculoskeletal pain syndromes. Furthermore, there is a lack of robust evidence validating the clinical diagnostic criteria for trigger point identification or diagnosis. High-quality studies have also demonstrated that manual examination for the identification and localization of a trigger point is neither valid nor reliable between-examiners. Conclusions: Several studies have demonstrated immediate or short-term improvements in pain and/or disability by targeting trigger points (TrPs) using in-and-out techniques such as ‘pistoning’ or

  8. Computed tomography-guided percutaneous catheter drainage of primary and secondary iliopsoas abscesses

    Energy Technology Data Exchange (ETDEWEB)

    Cantasdemir, M. E-mail:; Kara, B.; Cebi, D.; Selcuk, N.D.; Numan, F


    AIM: To report our experience with computed tomography (CT)-guided percutaneous catheter drainage (PCD) of iliopsoas abscesses. MATERIALS AND METHODS: Twenty-two iliopsoas abscesses in 21 patients (11 women, 10 men) aged between 18 and 66 years (mean 36 years) were treated with PCD. Abdominal CT demonstrated the iliopsoas abscesses, which were definitively determined by Gram staining and aspirate cultures. Twenty of the 22 iliopsoas abscesses were primary and two were secondary. All PCD procedures were performed under local anaesthesia using a single-step trocar technique (n=19) or Seldinger technique (n=3). RESULTS: PCD was an effective treatment in 21 out of the 22 iliopsoas abscesses. Recurrence was seen in three abscesses as minimal residual collections. Two of them resolved spontaneously with anti-tuberculous regimen. One required percutaneous needle aspiration. The procedure failed in a diabetic patient with a secondary abscess, who died due to sepsis. The length of time that catheters remained in place ranged from 21 to 75 days (mean 59.7 days). Complications included catheter dislocation in four abscesses, which required removal of dislocated catheters and indwelling new ones. CONCLUSION: CT-guided PCD is a safe and effective front-line treatment of iliopsoas abscesses. Surgery should be reserved for failure of PCD and presence of contraindications to PCD.

  9. Position Control of Motion Compensation Cardiac Catheters (United States)

    Kesner, Samuel B.; Howe, Robert D.


    Robotic catheters have the potential to revolutionize cardiac surgery by enabling minimally invasive structural repairs within the beating heart. This paper presents an actuated catheter system that compensates for the fast motion of cardiac tissue using 3D ultrasound image guidance. We describe the design and operation of the mechanical drive system and catheter module and analyze the catheter performance limitations of friction and backlash in detail. To mitigate these limitations, we propose and evaluate mechanical and control system compensation methods, including inverse and model-based backlash compensation, to improve the system performance. Finally, in vivo results are presented that demonstrate that the catheter can track the cardiac tissue motion with less than 1 mm RMS error. The ultimate goal of this research is to create a fast and dexterous robotic catheter system that can perform surgery on the delicate structures inside of the beating heart. PMID:21874124

  10. Infections associated with the central venous catheters. (United States)

    Drasković, Biljana; Fabri, Izabella; Benka, Anna Uram; Rakić, Goran


    Central venous catheters are of an essential importance to critically ill patients who require long-term venous access for various purposes. Their use made the treatment much easier, but still they are not harmless and are prone to numerous complications. Catheter infections represent the most significant complication in their use. The frequency of infections varies in different patient care settings, but their appearance mostly depends on the patient's health condition, catheter insertion time, localization of the catheter and type of the used catheter. Since they are one of the leading causes of nosocomial infections and related to significant number of morbidity and mortality in intensive care units, it is very important that maximal aseptic precautions are taken during the insertion and the maintenance period. Prevention of infection of the central venous catheters demands several measures that should be applied routinely.

  11. Dry needling — peripheral and central considerations


    Dommerholt, Jan


    Dry needling is a common treatment technique in orthopedic manual physical therapy. Although various dry needling approaches exist, the more common and best supported approach targets myofascial trigger points. This article aims to place trigger point dry needling within the context of pain sciences. From a pain science perspective, trigger points are constant sources of peripheral nociceptive input leading to peripheral and central sensitization. Dry needling cannot only reverse some aspects...

  12. A case of misplaced permacath dialysis catheter

    Directory of Open Access Journals (Sweden)

    Mohammed Arshad Ali


    Full Text Available Central venous placement using ultrasound has significantly reduced the complications associated with blind puncture. The central venous catheter can still get misplaced if it follows an anomalous route after appropriate puncture of desired vessel. We report a case of misplaced dialysis catheter into the accessory hemiazygos vein which resulted in a large hemothorax, and we recommend the routine use of a fluoroscope for placement of dialysis catheters so as to avoid serious complications.

  13. Impact of different catheter lock strategies on bacterial colonization of permanent central venous hemodialysis catheters. (United States)

    Erb, Stefan; Widmer, Andreas F; Tschudin-Sutter, Sarah; Neff, Ursula; Fischer, Manuela; Dickenmann, Michael; Grosse, Philipp


    Thirty-nine hemodialysis patients with permanent central venous catheters were analyzed for bacterial catheter colonization comparing different catheter-lock strategies. The closed needleless Tego connector with sodium chloride lock solution was significantly more frequently colonized with bacteria than the standard catheter caps with antimicrobially active citrate lock solution (odds ratio, 0.22 [95% confidence interval, 0.07-0.71]; P = .011).

  14. Needle-free influenza vaccination

    NARCIS (Netherlands)

    Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Frijlink, Henderik W.; Wilschut, Jan C.; Huckriede, Anke


    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 distribut

  15. Malposition of catheters during voiding cystourethrography

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, V.; Konen, O.; Shapiro, M. [Dept. of Diagnostic Imaging Sapir Medical Center, Kfar-Saba and Sackler Medical School, Tel Aviv University (Israel); Grunebaum, M. [Veteran Pediatric Radiologist, Kfar Saba (Israel)


    The aim of this study was to report catheter malposition during voiding cystourethrography. Eight hundred forty-three voiding cystourethrography (265 males and 578 females, aged 1 week to 12 years, mean age 2 years) were performed during a period of 4 years. The conventional standard procedure was applied. In 3 cases with passed history of urinary tract infection the catheter entered directly into the ureter. In all these cases the uretero-vesical reflux was present on the same side where the catheter entered. It appears that insertion of a catheter into the ureter is possible only in the presence of an anomaly or pathology at the vesicoureteric junction. (orig.)

  16. Erroneous laboratory values obtained from central catheters. (United States)

    Johnston, J B; Messina, M


    Serious analytic errors in potassium measurements have been identified in blood specimens obtained from newly inserted central catheters. Erroneous elevated readings have been related to interactions of chemistry analyzer electrodes and substances fixed to external and intraluminal walls of the central catheter. Anecdotal summaries of this phenomenon are presented to enable the nurse to recognize potential problems when sampling blood from central catheters. Studies were performed to determine the amount of flush necessary to clear the catheter of interfering residue. To eliminate this potentially hazardous occurrence, recommended flush volumes, nursing implications, and actions are described.

  17. Switching a Nanocluster Core from Hollow to Non-hollow

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa


    Modulating the structure-property relationship in atomically precise nanoclusters (NCs) is vital for developing novel NC materials and advancing their applications. While promising biphasic ligand-exchange (LE) strategies have been developed primarily to attain novel NCs, understanding the mechanistic aspects involved in tuning the core and the ligand-shell of NCs in such biphasic processes is challenging. Here, we design a single phase LE process that enabled us to elucidate the mechanism of how a hollow NC (e.g., [Ag44(SR)30]4-, -SR: thiolate) converts into a non-hollow NC (e.g., [Ag25(SR)18]-), and vice versa. Our study reveals that the complete LE of the hollow [Ag44(SPhF)30]4- NCs (–SPhF: 4-fluorobenzenethiolate) with incoming 2,4-dimethylbenzenethiol (HSPhMe2) induced distortions in the Ag44 structure forming the non-hollow [Ag25(SPhMe2)18]- by a disproportionation mechanism. While the reverse reaction of [Ag25(SPhMe2)18]- with HSPhF prompted an unusual dimerization of Ag25, followed by a rearrangement step that reproduces the original [Ag44(SPhF)30]4-. Remarkably, both the forward and the backward reactions proceed through similar size intermediates that seem to be governed by the boundary conditions set by the thermodynamic and electronic stability of the hollow and non-hollow metal cores. Furthermore, the resizing of NCs highlights the surprisingly long-range effect of the ligands which are felt by atoms far deep in the metal core, thus opening a new path for controlling the structural evolution of nanoparticles.

  18. Compensating for Torsion Windup in Steerable Needles (United States)

    Reed, Kyle B.


    Long, flexible, bevel-tip needles curve during insertion into tissue, and rotations of the needle base reorient the tip to steer subsequent insertions. Friction between the tissue and the needle shaft, however, can cause a severe discrepancy between the needle base and tip angles. In this paper, I demonstrate an algorithm to properly align the entire length of the needle using torque measured at the base. My algorithm uses several intermediate base rotations to align the orientation of points along the shaft with the desired angle, with minimal remaining torque exerted by the base. I performed an experimental validation with four angle sensors attached to the needle throughout the tissue. My compensation algorithm decreased the lag throughout the needle by up to 88%. PMID:20640198

  19. Influence of breed and age on morphometry and depth of inseminating catheter penetration in the ewe cervix: a postmortem study. (United States)

    Kaabi, M; Alvarez, M; Anel, E; Chamorro, C A; Boixo, J C; de Paz, P; Anel, L


    A detailed examination of the cervical canal in the ewe was carried out. This analysis could be used to design new catheters for artificial insemination (AI) to achieve deeper cervical penetration and therefore better fertility results. Three hundred and sixty-five cervices from four sheep breeds (Churra, Assaf, Merino, Castellana) obtained postmortem were used. Cervix morphometry and depth of cervical penetration using two types of catheters were determined. A conventional straight catheter for ovine artificial insemination (IMV), and a bent catheter, ending in a stainless steel needle, 9 cm in length and with an 8 mm tip bent 45 degrees , were used. The results showed that the morphometry of the cervix depends on breed and age of the ewe. The cervices of Churra breed were shorter and narrower, and had a higher number of folds than those of other breeds. Postmortem cervical penetration was deeper when the cervices were longer and wider, and with fewer folds (Merino and Castellana breeds). In ageing ewes, the cervix tended to become longer and wider, with loose folds. This decreased structural complexity and significantly improved cervical penetration. The bent catheter allowed significantly greater cervical penetration than the straight IMV one.

  20. Quartz antenna with hollow conductor (United States)

    Leung, Ka-Ngo; Benabou, Elie


    A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

  1. Hollow waveguide for urology treatment (United States)

    Jelínková, H.; Němec, M.; Koranda, P.; Pokorný, J.; Kőhler, O.; Drlík, P.; Miyagi, M.; Iwai, K.; Matsuura, Y.


    The aim of our work was the application of the special sealed hollow waveguide system for the urology treatment - In our experimental study we have compared the effects of Ho:YAG (wavelength 2100 nm) and Er:YAG (wavelength 2940 nm) laser radiation both on human urinary stones (or compressed plaster samples which serve as a model) fragmentation and soft ureter tissue incision in vitro. Cyclic Olefin Polymer - coated silver (COP/Ag) hollow glass waveguides with inner and outer diameters 700 and 850 μm, respectively, were used for the experiment. To prevent any liquid to diminish and stop the transmission, the waveguide termination was utilized.

  2. Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers. (United States)

    Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György


    at positions (+/- standard deviation) -0.53 +/- 0.16, -0.16 +/- 0.14, and -0.30 +/- 0.16 mm using a gain of 15 dB. The minus sign indicates that the needle tips were detected more proximally than the actual position of the needle tip. When using a gain of -15 dB the mean values of two observers resulted in -0.62 +/- 0.08 and -0.51 +/- 0.12 mm. Additionally an alternative approach to the direct needle tip definition was investigated. Two observers detected the solid part of the needle tip in sagittal images. This solid part, often named as "dead space end," is the distance between the needle tip and the beginning of the hollow part of the implant needle. The dead space end is 6.2 mm for the investigated needle type. Two users found mean values of -6.70 +/- 0.16 and -7.00 +/- 0.06 mm, respectively, for 15 dB gain and -6.90 +/- 0.09 and -7.02 +/- 0.06 mm using the -15 dB gain setting. The results show that ultrasound-based needle tip definition in sagittal viewing mode is accurate. The inter- and intraobserver errors should, however, be taken into account. A lower gain setting of the ultrasound system reduces the intraobserver error.

  3. Soft thrombus formation in radiofrequency catheter ablation

    NARCIS (Netherlands)

    Demolin, JM; Eick, OJ; Munch, K; Koullick, E; Nakagawa, H; Wittkampf, FHM


    During RF catheter ablation, local temperature elevation can result in coagulum formation on the ablation electrode, resulting in impedance rise. A recent study has also demonstrated the formation of a so-called soft thrombus during experimental ablations. This deposit poorly adhered to the catheter

  4. Catheter ablation of parahisian premature ventricular complex. (United States)

    Kim, Jun; Kim, Jeong Su; Park, Yong Hyun; Kim, June Hong; Chun, Kook Jin


    Catheter ablation is performed in selected patients with a symptomatic premature ventricular complex (PVC) or PVC-induced cardiomyopathy. Ablation of PVC from the His region has a high risk of inducing a complete atrioventricular block. Here we report successful catheter ablation of a parahisian PVC in a 63-year-old man.

  5. Urethral catheters: can we reduce use?

    NARCIS (Netherlands)

    Broek, P.J. van den; Wille, J.C.; Benthem, B.H.B. van; Perenboom, R.J.M.; Akker-van Marle, M.E. van den; Nielen, A.M.A.


    Indwelling urinary catheters are the main cause of healthcare-associated urinary tract infections. It can be expected that reduction of the use of urinary catheters will lead to decreased numbers of urinary tract infection. The efficacy of an intervention programme to improve adherence to recommenda

  6. Automated Pointing of Cardiac Imaging Catheters. (United States)

    Loschak, Paul M; Brattain, Laura J; Howe, Robert D


    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control.

  7. Attitudes Towards Catheter Ablation for Atrial Fibrillation

    DEFF Research Database (Denmark)

    Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis;


    BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...

  8. Myocardium tissue ablation with hollow-waveguide-delivered near-infrared nanosecond laser pulses (United States)

    Sato, Shunichi; Arai, Tsunenori; Shi, Yi-Wei; Matsuura, Yuji; Miyagi, Mitsunobu; Ashida, Hiroshi


    With 1064-nm, nanosecond laser pulses delivered from hollow waveguide, ablation characteristics of porcine myocardium tissue have been investigated in vitro. For the hollow waveguide a vacuum-cored scheme was introduced to suppress the laser-induced air breakdown that limited the available transmitted laser energy/power. The delivered laser pulse beam was focused with a collimation lens and a focusing lens, and it was shown that higher efficiency ablation was obtained when a focusing lens with a shorter focal length was used. Waveguide bending (bending angle 90 degree(s)C, bending radius approximately 50 cm) caused no deteriorating effect on the ablation characteristics for ablation energies up to approximately 60 mJ/pulse. It was demonstrated that deep and sharp ablated holes with aspect ratios > 8 was obtained with the hollow-waveguide-delivered laser pulses. It may be a realistic option to aim at using the present hollow waveguide system for trocar-based applications or replacing articulated mirror-based laser delivery systems. It is an important part of the future works to downsize the waveguide output unit for catheter-based applications.

  9. Unusual migration of pulmonary artery catheter

    Directory of Open Access Journals (Sweden)

    Sanjay Kuravinakop


    Full Text Available Pulmonary artery catheter is widely used in intensive care. Distal migration of the catheter is a know complication. Diagnosis of such a migration is made by both clinical criteria and radiographs. A 55 year old septic lady was admitted to the intensive care unit. Pulmonary artery catheter introduced for cardiac output monitoring migrated from right lung to left lung. Diagnosis was made following a chest radiograph the following day of insertion with the clinical criteria remaining unaltered. Migration of pulmonary artery catheter can occur not only distally but from one lung to another. Clinical criteria alone cannot rule out migration. Chest radiographs form an important part in monitoring the position of the pulmonary artery catheter.

  10. Central Venous Catheter-Related Hydrothorax

    Directory of Open Access Journals (Sweden)

    Se Hun Kim


    Full Text Available This report describes a case of 88-year-old women who developed central venous catheter-related bilateral hydrothorax, in which left pleural effusion, while right pleural effusion was being drained. The drainage prevented accumulation of fluid in the right pleural space, indicating that there was neither extravasation of infusion fluid nor connection between the two pleural cavities. The only explanation for bilateral hydrothorax in this case is lymphatic connections. Although vascular injuries by central venous catheter can cause catheter-related hydrothorax, it is most likely that the positioning of the tip of central venous catheter within the lymphatic duct opening in the right sub-clavian-jugular confluence or superior vena cava causes the catheter-related hydrothorax. Pericardial effusion can also result from retrograde lymphatic flow through the pulmonary lymphatic chains.

  11. Central venous catheters: detection of catheter complications and therapeutical options; Zentralvenoese Katheter: Diagnostik von Komplikationen und therapeutische Optionen

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, B.; Beck, A. [Universitaetsmedizin Charite, Berlin (Germany). Klinik fuer Strahlenheilkunde; Wagner, H.J. [Vivantes-Kliniken, Friedrichshain und Am Urban, Berlin (Germany). Radiologie; Vivantes-Kliniken, Hellersdorf und Prenzlauer Berg (Germany). Radiologie


    For modern medicine central venous catheters play an important role for diagnostic and therapeutic options. Catheter implantation, complication detection and therapy of catheter complications are an increasing demand for the radiologist. The review article provides an overview of different catheter types, their indications, advantages and disadvantages. Catheter malpositions are usually detectable in conventional X-ray. Most malpositions are correctable using interventional-radiological techniques. In addition therapeutical options for thrombotic complications (venous thrombosis, catheter occlusion, fibrin sheath) are discussed. In case of an infectious catheter complication, usually a catheter extraction and re-implantation is necessary.

  12. Be on Pins and Needles

    Institute of Scientific and Technical Information of China (English)



    英语对话:A:It seems you’re on pins and needles today.Anything troubling you?B:Yeah.I don’t know why bad things keep happening to me .You see,mycar was stolen and the warehouse had been broken into.I can’t keep myfinger on the causes of this damned thing.A:There must be someone who had planned that.Do you have a partieularperson in mind?

  13. Evaluation of an intravenous catheter for use in the horse. (United States)

    Gulick, B A; Meagher, D M


    A commercially available polyvinyl chloride intravenous catheter was studied in 9 horses for 3 to 10 days to evaluate the catheter's suitability for use in the horse, to develop a new insertion technique, and to establish a protocol for catheter care. Seven of the animals were clinically normal horses receiving parenteral nutrition; one was a horse with hypocalcemia receiving frequent intravenous injections of calcium gluconate, and one was a clinically normal horse receiving no infusions. The catheter dressings were changed every 48 hours, and an aspirate from the catheter and the catheter tip was cultured at the time of catheter removal. One catheter became infected following a break in the protocol. It was concluded that the polyvinyl catheter is suitable for use in the horse and that the proposed protocol for catheter insertion and maintenance may reduce the likelihood of complications such as catheter sepsis, thrombophlebitis, and embolism.

  14. Hollow waveguide cavity ringdown spectroscopy (United States)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)


    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  15. Estimation of Model Parameters for Steerable Needles (United States)

    Park, Wooram; Reed, Kyle B.; Okamura, Allison M.; Chirikjian, Gregory S.


    Flexible needles with bevel tips are being developed as useful tools for minimally invasive surgery and percutaneous therapy. When such a needle is inserted into soft tissue, it bends due to the asymmetric geometry of the bevel tip. This insertion with bending is not completely repeatable. We characterize the deviations in needle tip pose (position and orientation) by performing repeated needle insertions into artificial tissue. The base of the needle is pushed at a constant speed without rotating, and the covariance of the distribution of the needle tip pose is computed from experimental data. We develop the closed-form equations to describe how the covariance varies with different model parameters. We estimate the model parameters by matching the closed-form covariance and the experimentally obtained covariance. In this work, we use a needle model modified from a previously developed model with two noise parameters. The modified needle model uses three noise parameters to better capture the stochastic behavior of the needle insertion. The modified needle model provides an improvement of the covariance error from 26.1% to 6.55%. PMID:21643451

  16. Estimation of Model Parameters for Steerable Needles. (United States)

    Park, Wooram; Reed, Kyle B; Okamura, Allison M; Chirikjian, Gregory S


    Flexible needles with bevel tips are being developed as useful tools for minimally invasive surgery and percutaneous therapy. When such a needle is inserted into soft tissue, it bends due to the asymmetric geometry of the bevel tip. This insertion with bending is not completely repeatable. We characterize the deviations in needle tip pose (position and orientation) by performing repeated needle insertions into artificial tissue. The base of the needle is pushed at a constant speed without rotating, and the covariance of the distribution of the needle tip pose is computed from experimental data. We develop the closed-form equations to describe how the covariance varies with different model parameters. We estimate the model parameters by matching the closed-form covariance and the experimentally obtained covariance. In this work, we use a needle model modified from a previously developed model with two noise parameters. The modified needle model uses three noise parameters to better capture the stochastic behavior of the needle insertion. The modified needle model provides an improvement of the covariance error from 26.1% to 6.55%.

  17. Radiologic placement of tunneled central venous catheter

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Seong Tae; Yang, Po Song; Yang, Dong Hunn; Kim, Ki Tae; Kim, Choon Yul; Shinn, Kyung Sub [The Catholic Univ. College of Medicine, Seoul (Korea, Republic of); Yun, Eun Joo [Korea Veterans Hospital, Seoul (Korea, Republic of)


    To evaluate the efficacy and safety of fluoroscopy-guided, radiologic placement of a tunneled central venous catheter into the superior vena cava (SVC). Thirty five patients underwent tunneled central venous catheter placement to facilitate long-term chemotherapy. They included 33 leukemic patients, one colon cancer patient, and one multiple myeloma patient. After confirming central venous patency with a injection of contrast media via the peripheral cephalic or basilic vein in the wrist joint, the subclavian vein was punctured under fluoroscopic guidance. A 7F double lumen TPN catheter was placed into the SVC through a subcutaneous tunnel in the anterior chest wall. Catheter placements were successful in all patients. The mean procedure time was 17.2minutes, mean fluooscopy time was 1.3minutes, mean number of punctures was 1.4, and mean volume of injhected contrast media was 43.5cc. Only two of all leukemic patients developed mild hematomas at the puncture site, but these soon resolved themselves. None of the patients developed pneumothorax or hemothorax. But late complications included local infection in two patients (6%) and thrombotic occlusion of the catheter in one (3%). The occluded catheter was successfully recanalized with Urokinase infusion. Fluoroscopy-guided, radiologic placement of a tunneled central venous catheter is an easy and safe method, and useful for patients requiring long-term venous access.

  18. Dry needling - peripheral and central considerations. (United States)

    Dommerholt, Jan


    Dry needling is a common treatment technique in orthopedic manual physical therapy. Although various dry needling approaches exist, the more common and best supported approach targets myofascial trigger points. This article aims to place trigger point dry needling within the context of pain sciences. From a pain science perspective, trigger points are constant sources of peripheral nociceptive input leading to peripheral and central sensitization. Dry needling cannot only reverse some aspects of central sensitization, it reduces local and referred pain, improves range of motion and muscle activation pattern, and alters the chemical environment of trigger points. Trigger point dry needling should be based on a thorough understanding of the scientific background of trigger points, the differences and similarities between active and latent trigger points, motor adaptation, and central sensitize application. Several outcome studies are included, as well as comments on dry needling and acupuncture.

  19. Dimensions of stabident intraosseous perforators and needles. (United States)

    Ramlee, R A; Whitworth, J


    Problems can be encountered inserting intraosseous injection needles through perforation sites. This in vitro study examined the variability and size compatibility of Stabident intraosseous injection components. The diameters of 40 needles and perforators from a single Stabident kit were measured in triplicate with a toolmakers microscope. One-way ANOVA revealed that mean needle diameter (0.411 mm) was significantly narrower than mean perforator diameter (0.427 mm) (p < 0.001). A frequency distribution plot revealed that needle diameter followed a normal distribution, indicating tight quality control during manufacture. The diameter of perforators was haphazardly distributed, with a clustering of 15% at the lower limit of the size range. However on no occasion was the diameter of a perforator smaller than that of an injection needle. We conclude that components of the Stabident intraosseous anaesthetic system are size-compatible, but there is greater and more haphazard variability in the diameter of perforators than injection needles.

  20. [Updating enteral feeding by catheter]. (United States)

    Rodríguez, T; Planas, M


    Intestinal nutrition can be administered orally or by means of a catheter; the latter method is the focus of this article. The authors' objective is to provide up-to-date information in a succinct manner about the enteral feeding technique. The authors hope health professionals know the advantages as well as the inconveniences of the latest intestinal nutrition advances regarding access ways and the means to administer these. Intestinal nutrition formulas will not be dealt with in this article. However, a health professional should know that there is a wide variety of diets available depending on the complexity of macronutrients included in a diet, the quantity of proteins in a mixture, and that these are designed, in addition to feeding, to treat the specific pathological process a patient suffers from, such as diabetes of cancer.

  1. Sliding Mode Control of Steerable Needles


    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.


    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little...

  2. Extraordinary Vessels Needling for Vascular Dementia

    Institute of Scientific and Technical Information of China (English)

    YU Jin; LAI Xin-sheng; HUANG Qiu-tang; XIAO Yuan-chun


    Purpose To observe the clinical efficacy of extraordinary vessels needling in treating vascular dementia. Method 39 cases vascular dementia were treated by acupoints selected from the eight extraordinary meridians and the time needling techniques such as eight methods of spiritual turtle, in accordance with time period and pattern identifition. Results 2 cases were cured, 30 cases improved and 7 cases failed; the total effective rate was 82.1%. Conclusion Extraordinary vessels needling has positive effects in treating vascular dementia.

  3. Cryoballoon Catheter Ablation in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cevher Ozcan


    Full Text Available Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

  4. Percutaneous catheter dilatation of carotid stenoses

    Energy Technology Data Exchange (ETDEWEB)

    Mathias, K.; Mittermayer, C.; Ensinger, H.; Neff, W.


    Thirty-one carotid artery stenoses were produced in thirty dogs by three different techniques. Twenty-three of these could be cured by transfemoral percutaneous catheter dilatation. High grade tight stenoses may present resistance which cannot be overcome by the catheter. Histological examination of the dilated vessels showed circumscribed changes in the vessel wall, with destruction of elastic membranes. From our experience of catheter dilatation of pelvic and lower limb arteries and of renal arteries, we consider it feasible to use this technique in selected patients with carotid stenosis.

  5. Catheter-directed Thrombolysis in Acute Superior Vena Cava Syndrome Caused by Central Venous Catheters. (United States)

    Cui, Jie; Kawai, Tasuo; Irani, Zubin


    Indwelling central venous catheters have been reported to increase the risk of superior venous cava (SVC) syndrome. This case report describes the development of acute SVC syndrome in a 28-year-old woman with end-stage renal disease implanted with a left-side hemodialysis reliable outflow graft and a right-side double lumen hemodialysis catheter via internal jugular veins. Her symptoms were not alleviated after catheter removal and systemic anticoagulation therapy. She was eventually treated with catheter-directed thrombolysis and a predischarge computer tomographic venogram on postthrombolytic procedure day 7 showed patent central veins and patient remained asymptomatic. This case demonstrates that catheter-directed thrombolysis can be safely employed to treat refractory catheter-induced acute SVC syndrome in end-stage renal disease patients.

  6. Retained Urethral Catheter Secondary to Placement in Proximal Ureter

    Directory of Open Access Journals (Sweden)

    Thomas B. McGregor


    Full Text Available We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter.

  7. Retained Urethral Catheter Secondary to Placement in Proximal Ureter. (United States)

    McGregor, Thomas B; Sharda, Rajan


    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter.

  8. Freehand biopsy guided by electromagnetic needle tracking

    DEFF Research Database (Denmark)

    Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann


    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....

  9. Needle-Tissue Interaction Forces for Bevel-Tip Steerable Needles


    Misra, Sarthak; Reed, Kyle B.; Douglas, Andrew S.; Ramesh, K. T.; Okamura, Allison M.


    The asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. As a first step toward modeling the mechanics of deflection of the needle, we determine the forces at the bevel tip. In order to find the forces acting at the needle tip, we measure rupture toughness and nonlinear material elasticity parameters of several soft tissue simulant gels and chicken tissue. We incorporate these physical parameters into a finite element model that include...

  10. Electrocautery vs non-electrocautery dilation catheters in endoscopic ultrasonography-guided pancreatic fluid collection drainage

    Institute of Scientific and Technical Information of China (English)

    Katsuya Kitamura; Akira Yamamiya; Yu Ishii; Tomohiro Nomoto; Tadashi Honma; Hitoshi Yoshida


    AIM: To investigate the safety and utility of an electrocautery dilation catheter for endoscopic ultrasonography(EUS)-guided pancreatic fluid collection drainage.METHODS: A single-center, exploratory, retrospective study was conducted between August 2010 and August 2014. This study was approved by the Medical Ethics Committee of our institution. Informed, written consent was obtained from each patient prior to the procedure. The subjects included 28 consecutive patients who underwent EUS-guided transmural drainage(EUS-TD) for symptomatic pancreatic and peripancreatic fluid collections(PFCs) by fine needle aspiration using a 19-gauge needle. These patients were retrospectively divided into two groups based on the use of an electrocautery dilation catheter as a fistula dilation device; 15 patients were treated with an electrocautery dilation catheter(electrocautery group), and 13 patients were treated with a non-electrocautery dilation catheter(non-electrocautery group). We evaluated the technical and clinical successes and the adverse events associated with EUS-TD for the treatment of PFCs between the two groups.RESULTS: There were no significant differences in age, sex, type, location and diameter of PFCs between the groups. Thirteen patients(87%) in the electrocauterygroup and 10 patients(77%) in the non-electrocautery group presented with infected PFCs. The technical success rates of EUS-TD for the treatment of PFCs were 100%(15/15) and 100%(13/13) for the electrocautery and the non-electrocautery groups, respectively. The clinical success rates of EUS-TD for the treatment of PFCs were 67%(10/15) and 69%(9/13) for the electrocautery and the non-electrocautery groups, respectively(P = 0.794). The procedure time of EUS-TD for the treatment of PFCs in the electrocautery group was significantly shorter than that of the non-electrocautery group(mean ± SD: 30 ± 12 min vs 52 ± 20 min, P < 0.001). Adverse events associated with EUS-TD for the treatment of PFCs


    NARCIS (Netherlands)



    Some of the newer over-the-wire coronary angioplasty catheters have shaft sizes of 3.0 French (F) or less. The inner diameter of modern 8-F guiding catheters is large enough to accommodate two of such balloon catheters. We report a kissing balloon procedure with two over-the-wire catheters through a

  12. A subcutaneous Raman needle probe. (United States)

    Day, John C C; Stone, Nicholas


    Raman spectroscopy is a powerful tool for studying the biochemical composition of tissues and cells in the human body. We describe the initial results of a feasibility study to design and build a miniature, fiber optic probe incorporated into a standard hypodermic needle. This probe is intended for use in optical biopsies of solid tissues to provide valuable information of disease type, such as in the lymphatic system, breast, or prostate, or of such tissue types as muscle, fat, or spinal, when identifying a critical injection site. The optical design and fabrication of this probe is described, and example spectra of various ex vivo samples are shown.

  13. Using urokinase to restore patency in double lumen catheters. (United States)

    Northsea, C


    All hemodialysis patients with temporary or permanent double lumen catheters are at risk for catheter occlusion. Clinical outcomes and cost-effectiveness of using urokinase, a thrombolytic agent, to declot occluded double lumen dialysis catheters were evaluated for 2 years. Patency was restored in 95 of 102 catheters. These data support the use of urokinase to safely and effectively restore patency, thereby extending the length of time a catheter can be used for dialysis.

  14. A Survey of Invasive Catheter Practices in US Burn Centers (United States)


    central venous cannulation in children: lessons learned from a 10-year experience placing more than 1000 catheters . J Burn Care Res 2006;27:713–18. ...741 Central venous catheters (CVCs) and arterial catheters (ACs) provide essential access for critically injured patients. Practices surrounding...consisted of 23 questions related to spe- cific practices in placement and maintenance of central venous catheters (CVCs), arte- rial catheters ,

  15. 78 FR 60271 - Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of Application for Transfer of... (United States)


    ... Federal Energy Regulatory Commission Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of..., Hollow Dam Power Company (transferor) and Ampersand Hollow Dam Hydro, LLC (transferee) filed an application for transfer of license for the Hollow Dam Project, FERC No. 6972, located on the West Branch...

  16. Geographical and climatic limits of needle types of one- and two-needled pinyon pines (United States)

    Cole, K.L.; Fisher, J.; Arundel, S.T.; Cannella, J.; Swift, S.


    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

  17. Fabrication of Metallic Hollow Nanoparticles (United States)

    Kim, Jae-Woo (Inventor); Choi, Sr., Sang H. (Inventor); Lillehei, Peter T. (Inventor); Chu, Sang-Hyon (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)


    Metal and semiconductor nanoshells, particularly transition metal nanoshells, are fabricated using dendrimer molecules. Metallic colloids, metallic ions or semiconductors are attached to amine groups on the dendrimer surface in stabilized solution for the surface seeding method and the surface seedless method, respectively. Subsequently, the process is repeated with additional metallic ions or semiconductor, a stabilizer, and NaBH.sub.4 to increase the wall thickness of the metallic or semiconductor lining on the dendrimer surface. Metallic or semiconductor ions are automatically reduced on the metallic or semiconductor nanoparticles causing the formation of hollow metallic or semiconductor nanoparticles. The void size of the formed hollow nanoparticles depends on the dendrimer generation. The thickness of the metallic or semiconductor thin film around the dendrimer depends on the repetition times and the size of initial metallic or semiconductor seeds.

  18. Catheter-Associated Urinary Tract Infections (United States)

    ... Submit Button Frequently Asked Questions about Catheter-associated Urinary Tract Infections Recommend on Facebook Tweet Share Compartir What is ... an incision above the pubis. What is a urinary tract infection? A urinary tract infection (UTI) is an infection ...

  19. Hollow-core grating fiber (United States)

    Barillé, R.; Tajalli, P.; Roy, P.; Ahmadi-kandjani, S.; Kucharski, S.; Ortyl, E.


    We propose a new type of hollow-core fiber where the propagation is ensured by a photoinduced self-pattern acting as a surface relief grating (SRG). The SRG is written by launching a suitable laser beam with proper polarization in a capillary glass fiber with the inner surface previously coated with an azopolymer thin film. Such a grating acts as a wavelength/angle dependant reflective mirror and enhances the confinement and the propagation of the light.

  20. Purification of nanoparticles by hollow fiber diafiltration (United States)

    Veeken, J.


    Hollow Fiber Diafiltration (Hollow Fiber Tangential Flow Filtration) is an efficient and rapid alternative to traditional methods of nanoparticle purification such as ultracentrifugation, stirred cell filtration, dialysis or chromatography. Hollow Fiber Diafiltration can be used to purify a wide range of nanoparticles including liposomes, colloids, magnetic particles and nanotubes. Hollow Fiber Diafiltration is a membrane based method where pore size determines the retention or transmission of solution components. It is a flow process where the sample is gently circulated through a tubular membrane. With controlled replacement of the permeate or (dialysate), pure nanoparticles can be attained. Hollow Fiber Diafiltration can be directly scaled up from R&D volumes to production. By adding more membrane fibers and maintaining the operating parameters, large volumes can be processed in the same time with the same pressure, and flow dynamics as bench-scale volumes. Keywords: hollow fiber, Diafiltration, filtration, purification, tangential flow filtration.

  1. Cyclodextrin purification with hollow fibers

    Energy Technology Data Exchange (ETDEWEB)

    Berthod, A. (Univ. de Lyon 1, Villeubranne Cedex (France)); Jin, Heng Liang,; Armstrong, D.W. (Univ. of Missouri, Rolla (USA))


    Cyclodextrins are cyclic 1-4 linked oligomers of {alpha}-D-glucopyranose prepared from starch hydrolysis through enzymatic reactions. Mixtures of the three main cyclodextrins (CD), {alpha}-, {beta}-, and {gamma}-CDs, are always produced. A possible facile purification process is proposed. Permeation through hollow fibers made of a perfluorinated ionomer membrane. Nafion type, is shown to be an effective way to separate {alpha}-CD from {beta}- and {gamma}-CD. {Alpha}-CD with 95% purity was obtained after permeation through a Nafion hollow fiber of an equimolar 0.02 M solution of the three CDs. The fiber had a 56 cm{sup 2}/cm{sup 3} surface area per volume ratio. Kinetic studies and continuous extraction experiments with a 2-m coiled fiber showed that it is possible to obtain a 11.5 g {alpha}-CD solution with 92.4% purity or a 0.6 g {alpha}-CD solution with 97.2% purity, depending on the flow rate. The transport of CDs through the membrane could be due to moving water pools inside the ionomer. The small {alpha}-CD fits easily in such pools when the large {beta}- and {gamma}-CDs are excluded by steric hindrance. Temperature raises increased the permeation rates while decreasing the selectivity. The process could be scaled-up associating hollow fibers in bundle.

  2. Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid ... Needle Aspiration Biopsy of the Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? ...

  3. Space Charge Mitigation With Longitudinally Hollow Bunches

    CERN Document Server

    Oeftiger, Adrian; Rumolo, Giovanni; CERN. Geneva. ATS Department


    Suitably, hollow longitudinal phase space distributions have a flat profile and hence reduce the impact of transverse space charge. Dipolar parametric excitation with the phase loop feedback systems provides such hollow distributions under reproducible conditions. We present a procedure to create hollow bunches during the acceleration ramp of CERN’s PS Booster machine with minimal changes to the operational cycle. The improvements during the injection plateau of the downstream Proton Synchrotron are assessed in comparison to standard parabolic bunches.

  4. Space Charge Mitigation With Longitudinally Hollow Bunches

    CERN Multimedia

    Oeftiger, Adrian; Rumolo, Giovanni


    Hollow longitudinal phase space distributions have a flat profile and hence reduce the impact of transverse space charge. Dipolar parametric excitation with the phase loop feedback systems provides such hollow distributions under reproducible conditions. We present a procedure to create hollow bunches during the acceleration ramp of CERN’s PS Booster machine with minimal changes to the operational cycle. The improvements during the injection plateau of the downstream Proton Synchrotron are assessed in comparison to standard parabolic bunches.

  5. Hollow fibers for compact infrared gas sensors (United States)

    Lambrecht, A.; Hartwig, S.; Herbst, J.; Wöllenstein, J.


    Hollow fibers can be used for compact infrared gas sensors. The guided light is absorbed by the gas introduced into the hollow core. High sensitivity and a very small sampling volume can be achieved depending on fiber parameters i.e. attenuation, flexibility, and gas exchange rates. Different types of infrared hollow fibers including photonic bandgap fibers were characterized using quantum cascade lasers and thermal radiation sources. Obtained data are compared with available product specifications. Measurements with a compact fiber based ethanol sensor are compared with a system simulation. First results on the detection of trace amounts of the explosive material TATP using hollow fibers and QCL will be shown.

  6. Investigating the Effects of Three Needling Parameters (Manipulation, Retention Time, and Insertion Site on Needling Sensation and Pain Profiles: A Study of Eight Deep Needling Interventions

    Directory of Open Access Journals (Sweden)

    Bertrand Y. K. Loyeung


    Full Text Available 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.

  7. Freehand biopsy guided by electromagnetic needle tracking

    DEFF Research Database (Denmark)

    Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann


    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....

  8. Needle exchange programs in prisons in Spain. (United States)

    Menoyo, C; Zulaica, D; Parras, F


    On 11 July 2000, at the XIII International AIDS Conference in Durban, yet another country--Spain--presented evidence that needle exchange programs in prisons work. We reproduce here the text of the presentation entitled "Needle Exchange Program at the Bilbao Prison, Spain: Two Years of Experience (1997-1999)."


    Institute of Scientific and Technical Information of China (English)

    王斌; 董莉


    Acupuncture needle insertion always results in pain in the local area due to stimulating the free nerve endings—algesireceptors of the skin. In spite of mildness, this pain may induce many patients' fright, and thus, hinders more extensive application of acupuncture. In the present paper, the author introduces some methods for reducing needle insertion induced pain.

  10. Fine needle aspiration cytology of rectal masses. (United States)

    Kochhar, R; Rajwanshi, A; Wig, J D; Gupta, N M; Kesiezie, V; Bhasin, D K; Malik, A K; Gupta, S K; Mehta, S K


    This paper describes the results of transproctoscopic fine needle aspiration cytology in the diagnosis of rectal lesions. Fifty one consecutive patients referred with a presumptive diagnosis of rectal mass were subjected to proctoscopic examination when fine needle aspiration cytology, brush cytology and biopsy samples were taken. Of the 30 patients of malignancy of rectum in whom all the three sampling techniques were applied, the biopsy was positive in 27 (90%), brush cytology in 25 (83.3%) and fine needle aspiration cytology in 29 (96.6%). A combination of fine needle aspiration cytology with brush cytology gave a positive yield in 96.6% while that fine needle aspiration cytology with brush cytology gave a yield of 100%. Fine needle aspiration cytology was most helpful in infiltrative tumours. All 10 patients with secondaries in the pouch of Douglas or rectovesical pouch, and the single patient with submucosal rectal carcinoma were correctly diagnosed at fine needle aspiration cytology. There were no false positive results with fine needle aspiration cytology and no complications were encountered with the procedure. Images Figure 1 Figure 2 Figure 3 PMID:2323600

  11. An Elementary Account of Needle Insertion

    Institute of Scientific and Technical Information of China (English)

    张文兵; 霍则军


    @@ Based on the authors' clinical and personal experiences, several pain-inducing factors easily to be ignored by the operators when quick needle insertion is applied, and the authors' first invented slow painless needle insertion method are introduced in the article.

  12. Toxic catheters and urethral strictures: A concern about types of catheters used in resource-poor countries

    Directory of Open Access Journals (Sweden)

    A.A. Popoola


    Full Text Available Various reports in the literature have confirmed urethral toxicity caused by the use of catheters, mostly latex catheters and their coated versions, resulting in long-segment urethral strictures or strictures located in multiple areas of the urethra. Most catheters used in resource-poor countries, such as Nigeria, are latex catheters with various coatings, such as silicone. The reasons for the widespread use of these potentially toxic catheters are mainly non-availability and/or the high cost of less toxic catheters. We report three cases of urethral strictures following the use of siliconized latex catheters in order to highlight the potential urethral toxicity associated with the use of latex catheters and to draw the authorities’ attention to the need to regulate the types of catheters used in the country.

  13. Experience of robotic catheter ablation in humans using a novel remotely steerable catheter sheath (United States)

    Wallace, Daniel T.; Goldenberg, Alex S.; Peters, Nicholas S.; Davies, D. Wyn


    Background A novel remotely controlled steerable guide catheter has been developed to enable precise manipulation and stable positioning of any eight French (Fr) or smaller electrophysiological catheter within the heart for the purposes of mapping and ablation. Objective To report our initial experience using this system for remotely performing catheter ablation in humans. Methods Consecutive patients attending for routine ablation were recruited. Various conventional diagnostic catheters were inserted through the left femoral vein in preparation for treating an accessory pathway (n = 1), atrial flutter (n = 2) and atrial fibrillation (n = 7). The steerable guide catheter was inserted into the right femoral vein through which various irrigated and non-irrigated tip ablation catheters were used. Conventional endpoints of loss of pathway conduction, bidirectional cavotricuspid isthmus block and four pulmonary vein isolation were used to determine acute procedural success. Results Ten patients underwent remote catheter ablation using conventional and/or 3D non-fluoroscopic mapping technologies. All procedural endpoints were achieved using the robotic control system without manual manipulation of the ablation catheter. There was no major complication. A radiation dosimeter positioned next to the operator 2.7 m away from the X-ray source showed negligible exposure despite a mean cumulative dose area product of 7,281.4 cGycm2 for all ten ablation procedures. Conclusions Safe and clinically effective remote navigation of ablation catheters can be achieved using a novel remotely controlled steerable guide catheter in a variety of arrhythmias. The system is compatible with current mapping and ablation technologies Remote navigation substantially reduces radiation exposure to the operator. Electronic supplementary material The online version of this article (doi:10.1007/s10840-007-9184-z) contains supplementary material, which is available to authorized users

  14. Malfunctioning central venous catheters in children: a diagnostic approach

    Energy Technology Data Exchange (ETDEWEB)

    Barnacle, Alex; Arthurs, Owen J.; Roebuck, Derek; Hiorns, Melanie P. [Great Ormond Street Hospital, Radiology Department, London (United Kingdom)


    Central venous access is increasingly becoming the domain of the radiologist, both in terms of the insertion of central venous catheters (CVCs) and in the subsequent management of these lines. This article seeks to provide an overview of the CVC types available for paediatric patients and a more detailed explanation of the spectrum of complications that may lead to catheter malfunction. A standard catheter contrast study or 'linogram' technique is described. The normal appearances of such a study and a detailed pictorial review of abnormal catheter studies are provided, together with a brief overview of how information from catheter investigations can guide the management of catheter complications. (orig.)

  15. The Biological Safety of Stainless Steel Needles Used in Warm-Needling

    Directory of Open Access Journals (Sweden)

    Sabina Lim


    Full Text Available Warm-needling (also called thermo-acupuncture is a combination of acupuncture and moxibustion. Due to the intense heat involved, there have been concerns over the biological safety of the acuneedles used in the treatment. This paper reports two phases of a safety test. For a preliminary test, we compared the temperature change patterns of stainless steel (SS304 needles and traditional gold alloy needles, which have been increasingly replaced by the former. To verify the effects of the presence of coating materials, the main test involved three different kinds of SS304: silicone-coated, salicylic acid-coated and non-coated needles. Each group of needles was tested for pH level, heavy metals and UV absorbance spectrum along with biological tests on the cytotoxicity and hemolysis of the needle. All the tests on the extractants from the needles were negative. In the biological tests, each test result showed a significant difference from the positive control samples, while no significant difference was observed compared with the negative control samples. In the hemolysis tests, all samples satisfied the Korean Government Standards. All the results suggest that SS304 needles are biologically safe to be used in warm-needling, though they can be improved to perform as well as the gold alloy needles in terms of temperature fluctuations.

  16. Traumatic and nontraumatic perforation of hollow viscera. (United States)

    Espinoza, R; Rodríguez, A


    Hollow viscus injuries are usually managed with few complications. However, if their diagnosis is delayed, or if reparative suture closure should fail, the patient is placed at risk of multiple organ failure. This article presents diagnostic approaches, emphasizing imaging modalities, and therapeutic strategies for three clinical scenarios of hollow viscus perforation: 1) acute appendicitis, 2) gastroduodenal peptic ulcer disease, and 3) trauma.

  17. Adsorption characteristics of activated carbon hollow fibers



    Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  18. Nonholonomic catheter path reconstruction using electromagnetic tracking (United States)

    Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor


    Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.

  19. Needle muscle biopsy and its application

    Directory of Open Access Journals (Sweden)

    Meng-long CHEN


    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 

  20. Use of optimized ultrasound axis along with marked introducer needle to prevent mechanical complications of internal jugular vein catheterization

    Directory of Open Access Journals (Sweden)

    Tanmoy Ghatak


    Full Text Available Internal jugular vein (IJV catheterization is a routine technique in the intensive care unit. Ultrasound (US guided central venous catheter (CVC insertion is now the recommended standard. However, mechanical complications still occur due to non-visualization of the introducer needle tip during US guidance. This may result in arterial or posterior venous wall puncture or pneumothorax. We describe a new technique of (IJV catheterization using US, initially the depth of the IJV from the skin is measured in short-axis and then using real time US long-axis view guidance a marked introducer needle is advanced towards the IJV to the defined depth measured earlier in the short axis and the IJV is identified, assessed and cannulated for the CVC insertion. Our technique is simple and may reduce mechanical complications of US guided CVC insertion.

  1. Needle-Tissue Interaction Forces for Bevel-Tip Steerable Needles (United States)

    Misra, Sarthak; Reed, Kyle B.; Douglas, Andrew S.; Ramesh, K. T.; Okamura, Allison M.


    The asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. As a first step toward modeling the mechanics of deflection of the needle, we determine the forces at the bevel tip. In order to find the forces acting at the needle tip, we measure rupture toughness and nonlinear material elasticity parameters of several soft tissue simulant gels and chicken tissue. We incorporate these physical parameters into a finite element model that includes both contact and cohesive zone models to simulate tissue cleavage. We investigate the sensitivity of the tip forces to tissue rupture toughness, linear and nonlinear tissue elasticity, and needle tip bevel angle. The model shows that the tip forces are sensitive to the rupture toughness. The results from these studies contribute to a mechanics-based model of bevel-tip needle steering, extending previous work on kinematic models. PMID:22020139

  2. Needle-Tissue Interaction Forces for Bevel-Tip Steerable Needles. (United States)

    Misra, Sarthak; Reed, Kyle B; Douglas, Andrew S; Ramesh, K T; Okamura, Allison M


    The asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. As a first step toward modeling the mechanics of deflection of the needle, we determine the forces at the bevel tip. In order to find the forces acting at the needle tip, we measure rupture toughness and nonlinear material elasticity parameters of several soft tissue simulant gels and chicken tissue. We incorporate these physical parameters into a finite element model that includes both contact and cohesive zone models to simulate tissue cleavage. We investigate the sensitivity of the tip forces to tissue rupture toughness, linear and nonlinear tissue elasticity, and needle tip bevel angle. The model shows that the tip forces are sensitive to the rupture toughness. The results from these studies contribute to a mechanics-based model of bevel-tip needle steering, extending previous work on kinematic models.

  3. [Approach to teaching methods of the needling skill of filiform needle]. (United States)

    Wang, Cai-Hong; Xu, Jian-Min; Wang, Yin-Ping; Li, Yi


    The present paper is armed at approach to a set of teaching method about the needling skill of filiform needle, so as to increase teaching quality. After review and analysis on present situation of teaching methods about the needling skill of filiform needle, it is raised that traditional teaching methods are unable to objectively and comprehensively reflect characteristics and requirement of manipulation, so try to adopt acupuncture manipulation detection instrument, on the basis of traditional teaching methods about the needling skill of filiform needle. And the parameters and figures of manipulation examine of real-time collection in 131 students and information of 120 copies of questionnaire are analyzed and summarized. It is indicated that combined teaching method of traditional model and the manipulation instrument is more reasonable, and basic manipulation training most he strengthened in manipulation skill training, particularly, pay attention to training of twirling manipulation.

  4. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

    Energy Technology Data Exchange (ETDEWEB)

    Kuang Yuanwen [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Wen Dazhi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Zhou Guoyi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Liu Shizhong [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:


    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.

  5. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

    Energy Technology Data Exchange (ETDEWEB)

    Kuang Yuanwen [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Wen Dazhi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Zhou Guoyi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:; Liu Shizhong [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail:


    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.

  6. Pine needle abortion biomarker detected in bovine fetal fluids (United States)

    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...

  7. Microbiocidal effects of various taurolidine containing catheter lock solutions

    NARCIS (Netherlands)

    Olthof, E.D.; Nijland, R van; Gulich, A.F.; Wanten, G.J.A.


    BACKGROUND & AIMS: We have recently shown that a catheter lock solution containing taurolidine dramatically decreases catheter-related bloodstream infections (CRBSI) in patients on home parenteral nutrition (HPN) when compared to heparin. Since several taurolidine formulations are commercially avail

  8. A novel method for salvage of malfunctioning peritoneal dialysis catheter

    Directory of Open Access Journals (Sweden)

    Ali Akbar Beig


    Conclusions: Comparing the advantages and disadvantages of this method to the previous laparoscopically repaired catheter, we concluded that this new method is efficient, and is a suitable way for malfunctioning PD catheter salvage.

  9. Prevention of catheter-related Pseudomonas aeruginosa infection by levofloxacin-impregnated catheters in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    Yan Ping; Liu Wei; Kong Jinliang; Wu Hong; Chen Yiqiang


    Background Implanted medical catheter-related infections are increasing,hence a need for developing catheter polymers bonded to antimicrobials.We evaluated preventive effects of levofloxacin-impregnated catheters in catheterrelated Psuedomonas aeruginosa (strain PAO1) infection.Methods Drug release from levofloxacin-impregnated catheters was measured in vitro.Levofloxacin-impregnated catheters and polyvinyl chloride (PVC) catheters were immersed in 5 ml 50% Luria Bertani medium containing 108 CFU/ml Pseudomonas aeruginosa then incubated for 6,12,24 or 48 hours at 37℃ when bacteria adhering to the catheters and bacteria in the growth culture medium were determined.Impregnated and PVC catheters were singly implanted subcutaneously in mice,50 μl (107CFU) of PAO1 was injected into catheters.After the first and fifth days challenge,bacterial counts on implanted catheters and in surrounding tissues were determined microbiologically.Bacterial colonization and biofilm formation on implanted catheters were assessed by scanning electron microscopy.Results Drug release from levofloxacin-impregnated catheters was rapid.Levofloxacin-impregnated catheters had significantly fewer bacteria compared to PVC in vitro.After first and fifth day of challenge,no or significantly fewer bacteria adhered to impregnated catheters or in surrounding tissues compared to PVC.Scanning electron microscopical images after first day displayed from none to significantly fewer bacteria adhering to impregnated implanted catheters,compared to bacteria and microcolonies adhering to PVC catheters.After the fifth day,no bacteria were found on impregnated catheters,compared to clusters surrounding mucus-like substance and coral-shaped biofilms with polymorphonuclear leukocyte on PVC catheters.After the first day of challenge,secretion occurred in all implanted catheters with surrounding tissues mildly hyperaemic and swollen.After the fifth day,minute secretions inside impregnated catheters and no


    Energy Technology Data Exchange (ETDEWEB)

    Sexton, W.


    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to &apos

  11. Fabrication of functional hollow carbon spheres with large hollow interior as active colloidal catalysts

    Institute of Scientific and Technical Information of China (English)

    Qiang Sun; Guanghui Wang; Wencui Li; Xiangqian Zhang; Anhui Lu


    In this study,we have established a facile method to synthesize functional hollow carbon spheres with large hollow interior,which can act as active colloidal catalysts.The method includes the following steps:first,hollow polymer spheres with large hollow interior were prepared using sodium oleate as the hollow core generator,and 2,4-dihydroxybenzoic acid and hexamethylene tetramine (HMT) as the polymer precursors under hydrothermal conditions; Fe3+ or Ag+ cations were then introduced into the as-prepared hollow polymer spheres through the carboxyl groups; finally,the hollow polymer spheres can be pseudomorphically converted to hollow carbon spheres during pyrolysis process,meanwhile iron or silver nanoparticles can also be formed in the carbon shell simultaneously.The structures of the obtained functional hollow carbon spheres were characterized by TEM,XRD,and TG.As an example,Ag-doped hollow carbon spheres were used as colloid catalysts which showed high catalytic activity in 4-nitrophenol reduction reaction.

  12. Urinary catheterization diary – A useful tool in tracking causes of non-deflating Foley catheter

    Directory of Open Access Journals (Sweden)

    C.O. Okorie


    Conclusions: Most urinary catheters marketed in developing countries are unidentifiable after unpacking. A catheterization diary is a useful tool for solving catheter-related problems, and its application in health-care facilities should be encouraged. Companies marketing Foley catheters should print the catheter name on both the catheter packaging and on the catheter itself.

  13. [Medial venous catheter or midline (MVC)]. (United States)

    Carrero Caballero, Ma Carmen; Montealegre Sanz, María; Cubero Pérez, Ma Antonia


    Current clinical practice is characterised for importance of the patient's quality of life and the need to reduce the costs of their treatment. We search intravenous therapy alternatives that meet the needs of the patient, reducing the complications associated with the use of venous catheters. Scientific evidence shows that there are midline venous catheters that offer patients and professionals the possibility of extending the duration of infusion therapy, using more venous compatibility materials, and with less risk of infection. The Midlines are becoming in a safe an efficient device for intravenous therapy, continuous and intermittent infusion, provided the necessary care by expert nurses. Midline catheters are peripheral venous access devices between 3 to 10 inches in length (8 to 25 cm). Midlines are usually placed in an upper arm vein, such as the brachial or cephalic, and the distal extreme ends below the level of the axillary line. Midlines catheters implanted in the cephalic or deep basilica veins get more blood flow. This large blood volume justifies the lower risk of mechanical or chemical phlebitis. Midlines are routinely used for two to six weeks. Due that the extrem of these catheters does not extend beyond the axillary line, there are limitations for its use: type of infused drugs, velocity of infusion, etc. In general, solutions that have pH 5 to 9, or an osmolarity less than 500 mOsm are appropriate for infusion through a Midline. Its use is recommended in case of treatments over 7 days with low irritant capacity fluids. According to the Infusion Nurses Society's standards of practice, Midline catheters are appropriate for all intravenous fluids that would normally be administered through a short peripheral IV Importantly, due that the catheter does not pass through the central veins, Midlines can be placed without a chest X-ray to confirm placement. For certain situations, Midlines are suitable for acute units and even for care home settings

  14. Sliding Mode Control of Steerable Needles (United States)

    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.


    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation. PMID:25400527

  15. Biopsy needle detection in transrectal ultrasound. (United States)

    Ayvaci, Alper; Yan, Pingkun; Xu, Sheng; Soatto, Stefano; Kruecker, Jochen


    Using the fusion of pre-operative MRI and real time intra-procedural transrectal ultrasound (TRUS) to guide prostate biopsy has been shown as a very promising approach to yield better clinical outcome than the routinely performed TRUS only guided biopsy. In several situations of the MRI/TRUS fusion guided biopsy, it is important to know the exact location of the deployed biopsy needle, which is imaged in the TRUS video. In this paper, we present a method to automatically detect and segment the biopsy needle in TRUS. To achieve this goal, we propose to combine information from multiple resources, including ultrasound probe stability, TRUS video background model, and the prior knowledge of needle orientation and position. The proposed algorithm was tested on TRUS video sequences which have in total more than 25,000 frames. The needle deployments were successfully detected and segmented in the sequences with high accuracy and low false-positive detection rate.

  16. A Multi-Layered Needle Injection Simulator. (United States)

    Laufer, Shlomi; Kempton, Steve J; Maciolek, Kimberly; Terry, Aliyya; Ray, Rebeca D; Pugh, Carla M; Afifi, Ahmed M


    Insuring correct needle location is crucial in many medical procedures. This can be even more challenging for physicians injecting in a new location for the first time. Since they do not necessarily know how the tissue is supposed to feel, finding the correct location and correct depth can be difficult. In this study we designed a simulator for training needle injection. The simulator was fabricated to give a realistic feeling of injecting Botox® in the temporalis and the semispinalis muscles as part of migraine treatment. In addition the simulator provided real-time feedback of correct needle location. Nine residents and medical students evaluated the simulator. They made several errors that were corrected real time using the real time feedback provided. They found the simulator to be very useful and that the training significantly improved their confidence. The methods described in this study can easily be implemented for developing needle injection simulators for other anatomical locations.

  17. Sliding Mode Control of Steerable Needles. (United States)

    Rucker, D Caleb; Das, Jadav; Gilbert, Hunter B; Swaney, Philip J; Miga, Michael I; Sarkar, Nilanjan; Webster, Robert J


    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation.

  18. Inverse Kinematics of Concentric Tube Steerable Needles (United States)

    Sears, Patrick; Dupont, Pierre E.


    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints. PMID:23685532

  19. Missing Broken Needle During Caesarean Section

    Directory of Open Access Journals (Sweden)

    Chandana Das


    Full Text Available Breakage of the needle and missing while repairing the uterine wound during cesarean section is an uncommon event. Subsequently it was removed under fluoroscopic guidance on the 7th postoperative day

  20. Finite element model of needle electrode sensitivity (United States)

    Høyum, P.; Kalvøy, H.; Martinsen, Ø. G.; Grimnes, S.


    We used the Finite Element (FE) Method to estimate the sensitivity of a needle electrode for bioimpedance measurement. This current conducting needle with insulated shaft was inserted in a saline solution and current was measured at the neutral electrode. FE model resistance and reactance were calculated and successfully compared with measurements on a laboratory model. The sensitivity field was described graphically based on these FE simulations.

  1. 21 CFR 870.1230 - Fiberoptic oximeter catheter. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiberoptic oximeter catheter. 870.1230 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1230 Fiberoptic oximeter catheter. (a) Identification. A fiberoptic oximeter catheter is a device used to estimate the...

  2. Hollow Micro-/Nanostructures: Synthesis and Applications

    KAUST Repository

    Lou, Xiong Wen (David)


    Hollow micro-nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA,.

  3. Dry needling versus acupuncture: the ongoing debate. (United States)

    Zhou, Kehua; Ma, Yan; Brogan, Michael S


    Although Western medical acupuncture (WMA) is commonly practised in the UK, a particular approach called dry needling (DN) is becoming increasingly popular in other countries. The legitimacy of the use of DN by conventional non-physician healthcare professionals is questioned by acupuncturists. This article describes the ongoing debate over the practice of DN between physical therapists and acupuncturists, with a particular emphasis on the USA. DN and acupuncture share many similarities but may differ in certain aspects. Currently, little information is available from the literature regarding the relationship between the two needling techniques. Through reviewing their origins, theory, and practice, we found that DN and acupuncture overlap in terms of needling technique with solid filiform needles as well as some fundamental theories. Both WMA and DN are based on modern biomedical understandings of the human body, although DN arguably represents only one subcategory of WMA. The increasing volume of research into needling therapy explains its growing popularity in the musculoskeletal field including sports medicine. To resolve the debate over DN practice, we call for the establishment of a regulatory body to accredit DN courses and a formal, comprehensive educational component and training for healthcare professionals who are not physicians or acupuncturists. Because of the close relationship between DN and acupuncture, collaboration rather than dispute between acupuncturists and other healthcare professionals should be encouraged with respect to education, research, and practice for the benefit of patients with musculoskeletal conditions who require needling therapy.

  4. Hollow Core, Whispering Gallery Resonator Sensors

    CERN Document Server

    Ward, Jonathan M; Chormaic, Síle Nic


    A review of hollow core whispering gallery resonators (WGRs)is given. After a short introduction to the topic of whispering gallery resonators we provide a description of whispering gallery modes in hollow or liquid core WGRs. Next, whispering gallery mode (WGM) sensing mechanisms are outlined and some fabrication methods for microbubbles, microcapillaries and other tubular WGM devices are discussed. We then focus on the most common applications of hollow core WGRs, namely refractive index and temperature sensing, gas sensing, force sensing, biosensing, and lasing. The review highlights some of the key papers in this field and gives the reader a general overview of the current state-of-the-art.

  5. Designing hollow nano gold golf balls. (United States)

    Landon, Preston B; Mo, Alexander H; Zhang, Chen; Emerson, Chris D; Printz, Adam D; Gomez, Alan F; DeLaTorre, Christopher J; Colburn, David A M; Anzenberg, Paula; Eliceiri, Matthew; O'Connell, Connor; Lal, Ratnesh


    Hollow/porous nanoparticles, including nanocarriers, nanoshells, and mesoporous materials have applications in catalysis, photonics, biosensing, and delivery of theranostic agents. Using a hierarchical template synthesis scheme, we have synthesized a nanocarrier mimicking a golf ball, consisting of (i) solid silica core with a pitted gold surface and (ii) a hollow/porous gold shell without silica. The template consisted of 100 nm polystyrene beads attached to a larger silica core. Selective gold plating of the core followed by removal of the polystyrene beads produced a golf ball-like nanostructure with 100 nm pits. Dissolution of the silica core produced a hollow/porous golf ball-like nanostructure.

  6. Catheter Removal versus Retention in the Management of Catheter-Associated Enterococcal Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Jonas Marschall


    Full Text Available BACKGROUND: Enterococci are an important cause of central venous catheter (CVC-associated bloodstream infections (CA-BSI. It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI.

  7. Analysis of MESSENGER high-resolution images of Mercury's hollows and implications for hollow formation (United States)

    Blewett, David T.; Stadermann, Amanda C.; Susorney, Hannah C.; Ernst, Carolyn M.; Xiao, Zhiyong; Chabot, Nancy L.; Denevi, Brett W.; Murchie, Scott L.; McCubbin, Francis M.; Kinczyk, Mallory J.; Gillis-Davis, Jeffrey J.; Solomon, Sean C.


    High-resolution images from MESSENGER provide morphological information on the nature and origin of Mercury's hollows, small depressions that likely formed when a volatile constituent was lost from the surface. Because graphite may be a component of the low-reflectance material that hosts hollows, we suggest that loss of carbon by ion sputtering or conversion to methane by proton irradiation could contribute to hollows formation. Measurements of widespread hollows in 565 images with pixel scales <20 m indicate that the average depth of hollows is 24 ± 16 m. We propose that hollows cease to increase in depth when a volatile-depleted lag deposit becomes sufficiently thick to protect the underlying surface. The difficulty of developing a lag on steep topography may account for the common occurrence of hollows on crater central peaks and walls. Disruption of the lag, e.g., by secondary cratering, could restart growth of hollows in a location that had been dormant. Images at extremely high resolution (~3 m/pixel) show that the edges of hollows are straight, as expected if the margins formed by scarp retreat. These highest-resolution images reveal no superposed impact craters, implying that hollows are very young. The width of hollows within rayed crater Balanchine suggests that the maximum time for lateral growth by 1 cm is ~10,000 yr. A process other than entrainment of dust by gases evolved in a steady-state sublimation-like process is likely required to explain the high-reflectance haloes that surround many hollows.

  8. Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter. (United States)

    Chuang, Ming-Tsung; Wu, Ding-Kwo; Chang, Cheng-Ang; Shih, Ming-Chen Paul; Ou-Yang, Fu; Chuang, Chien-Han; Tsai, Yi-Fan; Hsu, Jui-Sheng


    The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010), a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days). The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days). All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

  9. [Femoral venous catheter: an unusual complication]. (United States)

    Garcia, P; Mora, A; Trambert, P; Maler, E; Courant, P


    We report an erratic course of a venous femoral catheter which was in the abdominal cavity in a patient with an haemoperitoneum and an hepatic injury. This complication led to an inefficiency of the transfusion and a worsening of the haemoperitoneum.

  10. Best practices in urinary catheter care. (United States)

    Herter, Rebecca; Kazer, Meredith Wallace


    Urinary catheterization is a common healthcare intervention used to manage urinary dysfunction that poses serious associated risks and complications. This article discusses methods of urinary catheterization and their indications, catheter-associated complications, and assessment and management strategies that home healthcare practitioners can employ to ensure best patient outcomes and minimize complications.

  11. Complications after placement of peritoneal catheter

    Directory of Open Access Journals (Sweden)

    Đurđević-Mirković Tatjana


    Full Text Available Introduction. Peritoneal dialysis is one of the modalities used for treatment of end-stage chronic kidney failure. Nowadays, this method is complementary to haemodialysis and renal transplantation. Owing to the rich vascularization of the peritoneum, it is used in the processes of osmosis and diffusion, enabling the removal of uremic material from the body. The procedure includes introduction of peritoneal fluid via the peritoneal catheter. Complications. The catheter is placed through the anterior abdominal wall with its tip positioned in the small pelvis. There are several techniques for catheter placement considered minimally invasive, which, however, may be associated with various complications. These complications can be divided into mechanical (catheter dysfunction, cuff protrusion, hernia, dialysate leaks, visceral perforation and infectious (early peritonitis, exit site or tunnel infection, surgical wounds. In most cases, such complications are rare and can be successfully managed using conservative therapy; however, in some situations severe complications can endanger the life of the patient. On-time recognition of complications, particularly in patients at risk, is of paramount importance for an effective treatment. The development of complications can increase the morbidity and the chance of treatment failure, and therefore transfer to haemodialysis. Conclusion. The preoperative evaluation and determination of the risk factors as well as the early recognition and adequate management of complications are essential in their prevention.

  12. Fabricating a hollow bulb obturator

    Directory of Open Access Journals (Sweden)

    Fatih Sari


    Full Text Available

    Obturators are generally used in the rehabilitation of the maxillectomy defects. Ideally, obturators should be light, properly fit and construction should be made easily. By decreasing the weight of the prosthesis, the retention and stability may be optimized to allow the obturator for function comfortably during mastication, phonation, and deglutition. In this case, a 65-year-old male patient underwent surgical removal of left part of the maxilla due to the squamous cell carcinoma. In this technique fabrication of a hollow bulb obturator prosthesis as a single unit in heat-cured acrylic resin using a single-step flasking procedure was described. The patient’s functional and esthetic expectations were satisfied.

  13. Epidural catheter fragment entrapment: a case report

    Directory of Open Access Journals (Sweden)

    Mohammadi M


    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 st1":*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Epidural catheters are seldom difficult to remove from patients. The breakage of the catheters is uncommon, troublesome and occasionally dangerous. "n"nCase presentation: A lumbar epidural catheter inserted in a 17 year-old man for applying anesthesia for internal fixation of femur fracture and subsequent postoperative epidural analgesia. In the third postoperative day, during unsuccessful attempt for removing the catheter, it was broken and was retained in his back. A CT- scan was performed and shows a fragment of catheter in the sub- laminar ligament between L3 and L4 without any connection with epidural space. As the patient had no complaint the fractured fragment was left in site and he was just followed up in the clinic."n"nConclusion: The knowledge of practical method in locating the retained epidural catheter, and the indication for surgical removal are very important. CT- scan is useful in showing the mechanism and locating the epidural catheter entrapment and facilitating surgical follow-up.

  14. Urethral catheters: can we reduce use?

    Directory of Open Access Journals (Sweden)

    van den Akker-van Marle M Elske


    Full Text Available Abstract Background Indwelling urinary catheters are the main cause of healthcare-associated urinary tract infections. It can be expected that reduction of the use of urinary catheters will lead to decreased numbers of urinary tract infection. Methods The efficacy of an intervention programme to improve adherence to recommendations to reduce the use of urethral catheters was studied in a before-after comparison in ten Dutch hospitals. The programme detected barriers and facilitators and each individual facility was supported with developing their own intervention strategy. Outcome was evaluated by the prevalence of catheters, alternatives such as diapers, numbers of urinary tract infections, the percentage of correct indications and the duration of catheterization. The costs of the implementation as well as the catheterization were evaluated. Results Of a population of 16,495 hospitalized patients 3335 patients of whom 2943 were evaluable for the study, had a urethral catheter. The prevalence of urethral catheters decreased insignificantly in neurology (OR 0.93; 95% CI 0.77 - 1.13 and internal medicine wards (OR 0.97; 95% CI 0.83 - 1.13, decreased significantly in surgical wards (OR 0.84; 95% CI 0.75 - 0.96, but increased significantly in intensive care (IC and coronary care (CC units (OR 1.48; 95% CI 1.01 - 2.17. The use of alternatives was limited and remained so after the intervention. Duration of catheterization decreased insignificantly in IC/CC units (ratio after/before 0.95; 95% CI 0.78 - 1.16 and neurology (ratio 0.97; 95% CI 0.80 - 1.18 and significantly in internal medicine (ratio 0.81; 95% CI 0.69 - 0.96 and surgery wards (ratio 0.80; 95% CI 0.71 - 0.90. The percentage of correct indications on the day of inclusion increased from 50 to 67% (p Conclusion Targeted implementation of recommendations from an existing guideline can lead to better adherence and cost savings. Especially, hospitals which use a lot of urethral catheters or

  15. Hollow-core tapered coupler for large inner diameter hollow-core optical fibers

    Institute of Scientific and Technical Information of China (English)

    Guiyao Zhou(周桂耀); Zhiyun Hou(侯峙云); Lantian Hou(侯蓝田); Jigang Liu(刘继刚)


    A novel hollow-core tapered coupler has been theoretically designed and fabricated by fiber drawing machine. The coupler's inner wall is coated with a polycrystalline GeO2 film. The coupling loss of hollow-core tapered coupler is about 0.2 dB. Hollow-core tapered coupler reduces the transmission loss of hollow-core optical fiber (HCOF) by 0.5 dB/m, therefore the coupler is suitable for coupling high power CO2 laser in industrial application.

  16. Hollow Alveolus-Like Nanovesicle Assembly with Metal-Encapsulated Hollow Zeolite Nanocrystals. (United States)

    Dai, Chengyi; Zhang, Anfeng; Liu, Min; Gu, Lin; Guo, Xinwen; Song, Chunshan


    Inspired by the vesicular structure of alveolus which has a porous nanovesicle structure facilitating the transport of oxygen and carbon dioxide, we designed a hollow nanovesicle assembly with metal-encapsulated hollow zeolite that would enhance diffusion of reactants/products and inhibit sintering and leaching of active metals. This zeolitic nanovesicle has been successfully synthesized by a strategy which involves a one-pot hydrothermal synthesis of hollow assembly of metal-containing solid zeolite crystals without a structural template and a selective desilication-recrystallization accompanied by leaching-hydrolysis to convert the metal-containing solid crystals into metal-encapsulated hollow crystals. We demonstrate the strategy in synthesizing a hollow nanovesicle assembly of Fe2O3-encapsulated hollow crystals of ZSM-5 zeolite. This material possesses a microporous (0.4-0.6 nm) wall of hollow crystals and a mesoporous (5-17 nm) shell of nanovesicle with macropores (about 350 nm) in the core. This hierarchical structure enables excellent Fe2O3 dispersion (3-4 nm) and resistance to sintering even at 800 °C; facilitates the transport of reactant/products; and exhibits superior activity and resistance to leaching in phenol degradation. Hollow nanovesicle assembly of Fe-Pt bimetal-encapsulated hollow ZSM-5 crystals was also prepared.

  17. Repositioning of malpositioned or flipped central venous catheters

    Energy Technology Data Exchange (ETDEWEB)

    Thalhammer, A.; Jacobi, V.; Balzer, J.; Vogl, T.J. [Institute for Diagnostic and Interventional Radiology, Central Radiology Clinic, J.W. Goethe University, Frankfurt am Main (Germany)


    Primary misplaced or secondary flipped implanted catheters are located mostly in the right jugular vein. We demonstrate an effective method to replace fix implanted catheters such as Ports, Grochomg or Hickman catheters. Using a femoral venous approach, replacement into the superior vena cava can easily be done with a Sidewinder 1 catheter which is hooked over the misplaced central venous approach. In all our patients the method was successful. The repositioning technique described is simple, fast and has low costs. We can keep sterile conditions and do not need to solve the catheters' fixation. (orig.)

  18. Needle-in-Needle Technique for Percutaneous Retrieval of a Fractured Biopsy Needle during CT-Guided Biopsy of the Thoracic Spine. (United States)

    Shaikh, Hamza; Thawani, Jayesh; Pukenas, Bryan


    Common complications related to CT-guided percutaneous thoracic bone biopsy procedures include pneumothorax and muscular hematoma. Serious, but rare complications include paralysis, nerve injury, CSF leak, and aortic injury. Device failure has not been well documented in the literature. We discuss our experience with biopsy needle breakage during retrieval of a core specimen and the technique used to help retrieve an embedded needle using a CT fluoroscopic-guided, needle-in-needle approach. A 43 year-old man with Stage IIIa NSCLC was found to have a T11 vertebral body lesion as seen on PET, CT, and MR imaging. The patient underwent a CT-guided biopsy in the prone position. The T11 vertebral body was localized and cannulated using the percutaneous Bonopty(®) (Apriomed, Upsala, Sweden) needle device. After fine needle aspiration samples were obtained, a core needle biopsy was attempted with a 16-gauge device. The needle fractured 4 cm deep to the skin during removal of a sclerotic lesion, leaving a retained portion within the pedicle and vertebral body. Using CT-guided fluoroscopy, a large diameter Murphy M2 needle was advanced over the distal portion of the fractured Bonopty needle. The Murphy M2 needle was advanced distal to the tip of the Bonopty needle and removed, capturing the broken Bonopty penetration needle along with a core specimen. Larger-bore biopsy needle systems and/or a coaxial system should be used to perform core biopsies in sclerotic lesions to prevent device fracture. If there is device fracture, a larger-bore needle may be used to help capture the fractured needle and prevent open surgery.

  19. Hollow rhodoliths increase Svalbard's shelf biodiversity (United States)

    Teichert, Sebastian


    Rhodoliths are coralline red algal assemblages that commonly occur in marine habitats from the tropics to polar latitudes. They form rigid structures of high-magnesium calcite and have a good fossil record. Here I show that rhodoliths are ecosystem engineers in a high Arctic environment that increase local biodiversity by providing habitat. Gouged by boring mussels, originally solid rhodoliths become hollow ecospheres intensely colonised by benthic organisms. In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones. This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths. Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

  20. Methods for segmenting curved needles in ultrasound images. (United States)

    Okazawa, Stephen H; Ebrahimi, Richelle; Chuang, Jason; Rohling, Robert N; Salcudean, Septimiu E


    Ultrasound-guided percutaneous needle insertions are widely used techniques in current clinical practice. Some of these procedures have a high degree of difficulty because of poor observability of the needle in the ultrasound image. There have been recent efforts to improve guidance by computer assisted needle detection. These software techniques are often limited by not representing needle curvature. We present two methods to detect the needle in 2D ultrasound that specifically address needle curvature. Firstly, we demonstrate a real-time needle segmentation algorithm based on the Hough transform which detects the needle and represents its curved shape. Secondly, we demonstrate how a new coordinate transformation can transform detection of a curved needle to a linear fit. These methods are demonstrated on ultrasound and photographic images.

  1. Radiologically placed tunneled peritoneal catheter in palliation of malignant ascites

    Energy Technology Data Exchange (ETDEWEB)

    Akinci, Devrim; Erol, Bekir; Ciftci, Tuerkmen T. [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey); Akhan, Okan, E-mail: [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey)


    The purpose of this study was to evaluate retrospectively the safety and effectiveness of radiologically placed tunneled peritoneal catheter in palliation of malignant ascites. Between July 2005 and June 2009, 41 tunneled peritoneal catheters were placed under ultrasonographic and fluoroscopic guidance in 40 patients (mean age, 55 years; 22 women) who had symptomatic malignant ascites. No procedure related mortality was observed. Major complication occurred in one patient (2.5%) in the form of serious bacterial peritonitis that necessitated catheter removal. Minor complications such as minor bacterial peritonitis, catheter dislodgement, tunnel infection, and catheter blockage occurred in 11 patients (27.5%). The mean duration of survival after catheter placement was 11.8 weeks. All patients expired of their primary malignancies in the follow-up. Radiologically placed tunneled peritoneal catheter is safe and effective in palliation of symptomatic malignant ascites.

  2. The bowed catheter sign: a risk for pericardial tamponade

    Energy Technology Data Exchange (ETDEWEB)

    Towbin, Richard [Phoenix Children' s Hospital, Department of Radiology, Phoenix, AZ (United States)


    The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

  3. Needle deflection estimation using fusion of electromagnetic trackers. (United States)

    Sadjadi, H; Hashtrudi-Zaad, K; Fichtinger, G


    We present a needle deflection estimation method to compensate for needle bending during insertion into deformable tissue. We combine a kinematic needle deflection estimation model, electromagnetic (EM) trackers, and a Kalman filter (KF). We reduce the impact of error from the needle deflection estimation model by using the fusion of two EM trackers to report the approximate needle tip position in real-time. One reliable EM tracker is installed on the needle base, and estimates the needle tip position using the kinematic needle deflection model. A smaller but much less reliable EM tracker is installed on the needle tip, and estimates the needle tip position through direct noisy measurements. Using a KF, the sensory information from both EM trackers is fused to provide a reliable estimate of the needle tip position with much reduced variance in the estimation error. We then implement this method to compensate for needle deflection during simulated prostate cancer brachytherapy needle insertion. At a typical maximum insertion depth of 15 cm, needle tip mean estimation error was reduced from 2.39 mm to 0.31 mm, which demonstrates the effectiveness of our method, offering a clinically practical solution.

  4. Mode characteristics of hollow core Bragg fiber

    Institute of Scientific and Technical Information of China (English)

    Minning Ji; Zhidong Shi; Qiang Guo


    Analytical expression to calculate propagation constant and mode field of the hollow core Bragg fiber is derived. Numerical results are presented. It is shown that the fundamental mode of the hollow core Bragg fiber is circularly symmetric TE01 mode with no polarization degeneracy, while the higher order mode may be HE11, TM01, or TE02 etc.. This property is different from conventional optical fiber that its fundamental mode is the linearly polarized HE11 mode and is polarization degeneracy.


    Weir, Gordon W.; Lane, Michael


    Geologic mapping, geochemical sampling, and a search for prospects and mineralized rock in the Box-Death Hollow Roadless Area, Utah indicate that there is little promise for the occurrence of mineral or energy resources in the area. Additional exploratory drilling by industry seems warranted if wells elsewhere in the region find oil or gas in strata as yet untested in the Box-Death Hollow Roadless Area.

  6. Percutaneous Placement of Central Venous Catheters: Comparing the Anatomical Landmark Method with the Radiologically Guided Technique for Central Venous Catheterization Through the Internal Jugular Vein in Emergent Hemodialysis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Koroglu, M.; Demir, M.; Koroglu, B.K.; Sezer, M.T.; Akhan, O.; Yildiz, H.; Yavuz, L.; Baykal, B.; Oyar, O. [Suleyman Demirel Univ., Isparta (Turkey). Depts. of Radiology, Internal Medicine and Anesthesiology


    Purpose: To compare the success and immediate complication rates of the anatomical landmark method (group 1) and the radiologically (combined real-time ultrasound and fluoroscopy) guided technique (group 2) in the placement of central venous catheters in emergent hemodialysis patients. Material and Methods: The study was performed prospectively in a randomized manner. The success and immediate complication rates of radiologically guided placement of central venous access catheters through the internal jugular vein (n = 40) were compared with those of the anatomical landmark method (n 40). The success of placement, the complications, the number of passes required, and whether a single or double-wall puncture occurred were also noted and compared. Results: The groups were comparable in age and sex. The indication for catheter placement was hemodialysis access in all patients. Catheter placement was successful in all patients in group 2 and unsuccessful in 1 (2.5%) patient in group 1. All catheters functioned adequately and immediately after the placement (0% initial failure rate) in group 2, but 3 catheters (7.5% initial failure rate) were non-functional just after placement in group 1. The total number of needle passes, double venous wall puncture, and complication rate were significantly lower in group 2. Conclusion: Percutaneous central venous catheterization via the internal jugular vein can be performed by interventional radiologists with better technical success rates and lower immediate complications. In conclusion, central venous catheterization for emergent dialysis should be performed under both real-time ultrasound and fluoroscopic guidance.

  7. Temperature-controlled irrigated tip radiofrequency catheter ablation: comparison of in vivo and in vitro lesion dimensions for standard catheter and irrigated tip catheter with minimal infusion rate

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A;


    In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures <60% partly due to the limited lesion size after conventional radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion size, but has...... increased risk of cratering. The present study explores irrigated tip catheter ablation in temperature-controlled mode, target temperature 60 degrees C, using an irrigation rate of 1 mL/min, comparing this to conventional catheter technique, target temperature 80 degrees C.......In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures tip radiofrequency ablation using power control and high infusion rates enlarges lesion size, but has...

  8. Raman spectroscopy system with hollow fiber probes (United States)

    Liu, Bing-hong; Shi, Yi-Wei


    A Raman remote spectroscopy system was realized using flexible hollow optical fiber as laser emittion and signal collection probes. A silver-coated hollow fiber has low-loss property and flat transmission characteristics in the visible wavelength regions. Compared with conventional silica optical fiber, little background fluorescence noise was observed with optical fiber as the probe, which would be of great advantages to the detection in low frequency Raman shift region. The complex filtering and focusing system was thus unnecessary. The Raman spectra of CaCO3 and PE were obtained by using the system and a reasonable signal to noise ratio was attained without any lens. Experiments with probes made of conventional silica optical fibers were also conducted for comparisons. Furthermore, a silver-coated hollow glass waveguide was used as sample cell to detect liquid phase sample. We used a 6 cm-long hollow fiber as the liquid cell and Butt-couplings with emitting and collecting fibers. Experiment results show that the system obtained high signal to noise ratio because of the longer optical length between sample and laser light. We also give the elementary theoretical analysis for the hollow fiber sample cell. The parameters of the fiber which would affect the system were discussed. Hollow fiber has shown to be a potential fiber probe or sample cell for Raman spectroscopy.

  9. 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.


    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.

  10. Prevention of dialysis catheter-related sepsis with a citrate-taurolidine-containing lock solution.


    Betjes, Michiel; Agteren, Madelon


    textabstractBACKGROUND: The use of haemodialysis catheters is complicated by catheter-related sepsis. Intraluminal colonization of the catheter with bacteria is important in the pathogenesis of catheter-related sepsis. The use of a catheter lock solution containing the antimicrobial taurolidine might prevent bacterial colonization, thereby reducing the incidence of catheter-related sepsis. METHODS: In a randomized prospective trial, patients receiving a dialysis catheter were included and cat...

  11. Indwelling intrathecal catheter with subcutaneous abdominal reservoir: a viable baclofen delivery system in severely cachectic patients. (United States)

    Waqar, Mueez; Ellenbogen, Jonathan R; Kumar, Ram; Sneade, Christine; Zebian, Bassel; Williams, Dawn; Pettorini, Benedetta L


    Intrathecal baclofen (ITB) is a reversible treatment that reduces muscle tone to ameliorate spasticity and dystonia in patients with cerebral palsy (CP). The resulting decrease in energy expenditure allows patients to gain much-needed weight, albeit temporarily. Modern techniques require sufficient abdominal musculature and subcutaneous fat to permit the implantation of an indwelling pump. In patients with extremely low muscle bulk, visceral pumps may be impractical or impossible, with increased risks of dehiscence and infection. The authors describe a variation of the classical procedure in a young patient with severe cachexia. A 10-year-old boy with spastic-dystonic quadriplegic CP was admitted to the neuromedical unit. Numerous drug trials had failed, and surgical intervention was deemed necessary but was complicated by his cachectic body habitus. The authors inserted a lumbar intrathecal catheter and subcutaneously tunneled it to the anterolateral abdomen, where it was connected to a subcutaneous injection port. Baclofen was continuously infused into the subcutaneous port using a noncoring needle connected to an external pump. The needle and line were changed every 5 days to minimize the risk of sepsis. Although other techniques, such as intraventricular baclofen delivery, have been described, these are largely dependent upon sufficient musculature to support a visceral pump. A subcutaneous injection port system represents an alternative approach that reduces the risk of sepsis and may be better tolerated in cachectic patients.

  12. Perception and Action in Teleoperated Needle Insertion. (United States)

    Nisky, I; Pressman, A; Pugh, C M; Mussa-Ivaldi, F A; Karniel, A


    We studied the effect of delay on perception and action in contact with a force field that emulates elastic soft tissue with a rigid nonlinear boundary. Such a field is similar to forces exerted on a needle during teleoperated needle insertion. We found that delay causes motor underestimation of the stiffness of this nonlinear soft tissue, without perceptual change. These experimental results are supported by simulation of a simplified mechanical model of the arm and neural controller, and a model for perception of stiffness, which is based on regression in the force-position space. In addition, we show that changing the gain of the teleoperation channel cancels the motor effect of delay without adding perceptual distortion. We conclude that it is possible to achieve perceptual and motor transparency in virtual one-dimensional remote needle insertion task.

  13. Needle-free insulin drug delivery

    Directory of Open Access Journals (Sweden)

    Patni Preeti


    Full Text Available For most patients with type 1 diabetes, the worst part of the disease is to tolerate needle after needle, both for glucose measurement and to deliver insulin. In the last two decades, concept of insulin therapy by multiple-dose injection has undergone a miraculous change. Needle-free insulin delivery appeared to be a wonderful approach, and its allure rested in being comfortable and safe. In today′s era, insulin delivery by alternative route is a topic of current interest in the design of drug delivery system. Major global pharmaceutical companies are showing encouraging progress in their attempts to develop alternative insulin delivery technologies. Many such drug delivery systems have been developed for oral, buccal and nasal route. This review article discusses, in brief, the novel and emerging technologies that are in pipeline, including insulin inhalers, insulin spray, insulin pill, insulin analogues, insulin complement, islet cell transplant, implantable insulin pumps and guardian continuous glucose monitoring system.


    Institute of Scientific and Technical Information of China (English)

    GUO Jia-tu


    @@ Subcutaneous needling is a new therapeutic method which is based on the features of the meridian-collateral theory of cutaneous regions in traditional Chinese medicine and the neurohumeral theory and skin anatomy of modern medicine and is of the features of "fixed meridian but not fixed acupoints", "micro stimulation", and "subcutaneous needling with filiform needles" to achieve the goal of treating diseases. This method is indicated clinically to the analgesia and relaxation of spasm especially the pain caused by the disorders of the internal organs and marked therapeutic effect has been obtained. With method, 150 cases of epigastric pain were treated by our department and the total effective rate was over 90%. It is presented herein below.

  15. Transfemoral liver biopsy using a Quick-Core biopsy needle system in living donor liver transplantation recipients. (United States)

    Li, Fen Qiang; Ko, Gi-Young; Sung, Kyu-Bo; Gwon, Dong-Il; Ko, Heung Kyu; Kim, Jong Woo; Yu, Eunsil


    The purpose of this study was to evaluate the efficacy and safety of transfemoral liver biopsy with a Quick-Core biopsy needle in select living donor liver transplantation (LDLT) recipients. Eight LDLT recipients underwent 9 transfemoral liver biopsy sessions. Six patients had undergone modified right lobe (mRL) LDLT, and 2 patients had undergone dual-left lobe LDLT. The indications for transfemoral liver biopsy were a hepatic vein (HV) at an acute angle to the inferior vena cava (IVC) on the coronal plane and a thin (liver parenchyma surrounding the HV to be biopsied on enhanced computed tomography. Under fluoroscopic guidance, the right inferior HV in the mRL or the left HV in the right-sided left lobe with a cranial orientation was negotiated with a 5-Fr catheter via the common femoral vein. Then, a stiffening cannula was introduced into the HV over a stiff guide wire. Needle passage was then performed with an 18- or 19-gauge Quick-Core biopsy needle. Technical success was achieved in all sessions without major complications. The median number of needle passages was 4 (range = 2-6). The median total length of obtained liver specimens in each session was 44 mm (range = 24-75 mm). The median number of portal tracts was 18 (range = 10-29), and the obtained liver specimens were adequate for histological diagnosis in all sessions. In conclusion, transfemoral liver biopsy with a Quick-Core biopsy needle is an effective and safe alternative for obtaining a liver specimen when standard transjugular liver biopsy is not feasible because of an unfavorable HV angle with respect to the IVC and/or a thin liver parenchyma surrounding the HV.

  16. Evaluation of a novel Seldinger-needle for computed tomography guided interventions: initial experiences; Evaluierung einer neuen Seldinger-Nadel fuer computertomografisch gesteuerte Interventionen: Erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Plumhans, C.; Mahnken, A.; Iwa, R.; Behrendt, F.F.; Sebastian, K.; Guenther, R.W.; Honnef, D. [Universitaetsklinikum RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik


    To evaluate a new Seldinger puncture device for computed tomography-guided interventions under difficult conditions, to analyze applicability, and to investigate assets and drawbacks. From November 2007 to March 2008, we performed CT-guided interventions in 16 patients (7 women, 9 men; mean age 62 years old) using a new 20G-Seldinger needle (Sika-Med, Wiehl, Germany). This novel needle serves as a guide for many different interventional devices due to a guide wire welded on the proximal needle end. It allows continuous application of anesthesia via four tiny holes at the distal needle end until the region of interest is reached. Each intervention was subject to difficult interventional conditions. The indications for intervention were drainage (n = 7), Trucut biopsy of tumor (n = 8) and radiofrequency ablation (n = 1). Handling, success, advantages, drawbacks, complications and patient tolerance were noted after each procedure. A pain scale from 1 - 10 was used to grade the pain level during the intervention. All interventions were performed successfully and no severe complications were observed. Patient tolerance was very good resulting in a mean pain score of 2 {+-} 1. Regions with dangerous and difficult access were successfully reached with the new Seldinger needle in 15 of 16 cases by dilatation of the puncture tract and continuous administration of local anesthesia via the system. Furthermore, different devices such as Trucut systems and a drainage catheter were able to be inserted without complication via the needle. With a proximal removable luer-lock connection, liquid material was able to be aspirated in six cases. Under difficult interventional conditions, the use of a Seldinger needle as a reliable technique for CT-guided interventions can provide a safe and successful procedure. (orig.)

  17. Radiologic Placement of Tunneled Central Venous Catheters in Pediatric Patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ji; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jeong, Woo Kyoung; Lee, Yong Ho [Hanyang University College of Medicine, Seoul (Korea, Republic of)


    We evaluated the technical success and complication rates associated with the radiological placement of tunneled central venous catheters in pediatric patients. Between May 1, 2005 and March 31, 2008, a total of 46 tunneled central venous catheters were placed in 34 children (M:F = 22:12; mean age, 9.9 years [9 months to 16.8 years]). All procedures were performed under ultrasonographic and fluoroscopic guidance. Follow-up data were obtained through the retrospective review of the medical records. We used the Kaplan-Meier survival method for the evaluation of survival rate of the catheters. All procedures were technically successful. The observed periprocedural complications included hematoma formation in three patients. The mean catheter life was 189.3 days (total, 8710 days; range, 7-810). Catheters were removed due to death (n=9), the end of treatment (n=8), catheter sepsis (n=4), malfunction (n=8), and accidental removal (n=4). The rate of catheter sepsis and malfunction was 0.459 and 0.919 for every 1000 catheter days, respectively. The expected mean catheter life was 479.6 days as per the Kaplan- Meier analysis. The results suggest that the radiologic placement of a tunneled central venous catheter is an effective technique with a high technical success rate and low complication rate.

  18. Biological safety evaluation of the modified urinary catheter

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczuk, Dorota, E-mail: [Department of Medicinal Chemistry, Medical University of Lublin, Jaczewskiego 4, 20-090 Lublin (Poland); Przekora, Agata; Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1, 20-093 Lublin (Poland)


    The purpose of this study was to evaluate in vitro safety of the novel tosufloxacin (TOS)-treated catheters with the prolonged antimicrobial activity. The test samples of silicone latex catheter were prepared by the immobilization of TOS on chitosan (CHIT)-coated catheter by means of covalent bonds and non-covalent interactions. Each step of the modification process of catheter surface was observed using ATR–Fourier transform infrared spectroscopy. In vitro cytotoxicity of the modified and unmodified catheters was assessed by direct and indirect tests in accordance with ISO standards using green monkey kidney (GMK) cell line. The MTT, lactate dehydrogenase activity (LDH), WST-8, Sulforhodamine B (SRB) test results and microscopic observation clearly indicated that unmodified silicone latex catheters decrease cell metabolic activity, act as a cytotoxic agent causing cell lysis and induce cell death through necrotic or apoptotic process. We suggest that chitosan coat with TOS immobilized limits leaching of harmful agents from silicone latex material, which significantly enhances survivability of GMK cells and therefore is quite a good protection against the cytotoxic effect of this material. - Highlights: • Characterization of the novel antimicrobial urinary catheters • Monitoring of the catheter modification by FTIR analysis • Confirmation of high cytotoxicity of latex-based catheter used in urological practice • Chitosan-coated and tosufloxacin-treated catheter is less toxic than the untreated one. • The proposed surface modification protects cells against latex-induced death.

  19. Determination of the Stoichiometry of the Complete Bacterial Type III Secretion Needle Complex Using a Combined Quantitative Proteomic Approach. (United States)

    Zilkenat, Susann; Franz-Wachtel, Mirita; Stierhof, York-Dieter; Galán, Jorge E; Macek, Boris; Wagner, Samuel


    Precisely knowing the stoichiometry of their components is critical for investigating structure, assembly, and function of macromolecular machines. This has remained a technical challenge in particular for large, hydrophobic membrane-spanning protein complexes. Here, we determined the stoichiometry of a type III secretion system of Salmonella enterica serovar Typhimurium using two complementary protocols of gentle complex purification combined with peptide concatenated standard and synthetic stable isotope-labeled peptide-based mass spectrometry. Bacterial type III secretion systems are cell envelope-spanning effector protein-delivery machines essential for colonization and survival of many Gram-negative pathogens and symbionts. The membrane-embedded core unit of these secretion systems, termed the needle complex, is composed of a base that anchors the machinery to the inner and outer membranes, a hollow filament formed by inner rod and needle subunits that serves as conduit for substrate proteins, and a membrane-embedded export apparatus facilitating substrate translocation. Structural analyses have revealed the stoichiometry of the components of the base, but the stoichiometry of the essential hydrophobic export apparatus components and of the inner rod protein remain unknown. Here, we provide evidence that the export apparatus of type III secretion systems contains five SpaP, one SpaQ, one SpaR, and one SpaS. We confirmed that the previously suggested stoichiometry of nine InvA is valid for assembled needle complexes and describe a loose association of InvA with other needle complex components that may reflect its function. Furthermore, we present evidence that not more than six PrgJ form the inner rod of the needle complex. Providing this structural information will facilitate efforts to obtain an atomic view of type III secretion systems and foster our understanding of the function of these and related flagellar machines. Given that other virulence

  20. Pancreas tumor interstitial pressure catheter measurement (United States)

    Nieskoski, Michael D.; Gunn, Jason; Marra, Kayla; Trembly, B. Stuart; Pogue, Brian W.


    This paper highlights the methodology in measuring interstitial pressure in pancreatic adenocarcinoma tumors. A Millar Mikrotip pressure catheter (SPR-671) was used in this study and a system was built to amplify and filter the output signal for data collection. The Millar pressure catheter was calibrated prior to each experiment in a water column at 37°C, range of 0 to 60 inH2O (112 mmHg), resulting in a calibration factor of 33 mV / 1 inH2O. The interstitial pressures measured in two orthotopically grown pancreatic adenocarcinoma tumor were 57 mmHg and 48 mmHg, respectively. Verteporfin uptake into the pancreatic adenocarcinoma tumor was measured using a probe-based experimental dosimeter.

  1. Soft robotic concepts in catheter design: an on-demand fouling-release urinary catheter. (United States)

    Levering, Vrad; Wang, Qiming; Shivapooja, Phanindhar; Zhao, Xuanhe; López, Gabriel P


    Infectious biofilms are problematic in many healthcare-related devices and are especially challenging and ubiquitous in urinary catheters. This report presents an on-demand fouling-release methodology to mechanically disrupt and remove biofilms, and proposes this method for the active removal of infectious biofilms from the previously inaccessible main drainage lumen of urinary catheters. Mature Proteus mirabilis crystalline biofilms detach from silicone elastomer substrates upon application of strain to the substrate, and increasing the strain rate increases biofilm detachment. The study presents a quantitative relationship between applied strain rate and biofilm debonding through an analysis of biofilm segment length and the driving force for debonding. Based on this mechanism, hydraulic and pneumatic elastomer actuation is used to achieve surface strain selectively within the lumen of prototypes of sections of a fouling-release urinary catheter. Proof-of-concept prototypes of sections of active, fouling-release catheters are constructed using techniques typical to soft robotics including 3D printing and replica molding, and those prototypes demonstrate release of mature P. mirabilis crystalline biofilms (e.g., ≈90%) from strained surfaces. These results provide a basis for the development of a new urinary catheter technology in which infectious biofilms are effectively managed through new methods that are entirely complementary to existing approaches.

  2. Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal (United States)

    Urbanetto, Janete de Souza; Peixoto, Cibelle Grassmann; May, Tássia Amanda


    ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC) and following their removal - (post-infusion phlebitis) in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective. PMID:27508916

  3. Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal

    Directory of Open Access Journals (Sweden)

    Janete de Souza Urbanetto

    Full Text Available ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC and following their removal - (post-infusion phlebitis in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective.

  4. Biocide Activity against Urinary Catheter Pathogens


    Malic, Sladjana; Rachael P. C. Jordan; Waters, Mark G. J.; Stickler, David J.; Williams, David W


    Antimicrobial effects of essential oils against bacteria associated with urinary catheter infection was assessed. Tests were performed on 14 different bacterial species cultured either planktonically or as biofilms. Biofilms were found to be up to 8-fold more tolerant of the test agents. Higher antimicrobial tolerance was also evident in tests conducted in artificial urine. Eugenol exhibited higher antimicrobial effects against both planktonic cells and biofilms than did terpinen, tea tree oi...

  5. Transpleural central venous catheter discovered during thoracotomy

    Directory of Open Access Journals (Sweden)

    Ashima Malhotra


    Full Text Available We report an uncommon complication of subclavian central venous catheterization, discovered at thoracotomy. The central venous catheter (CVC was placed by left infraclavicular route after induction of general anesthesia. CVC was secured after aspiration of blood and satisfactory central venous tracing. On thoracotomy, CVC was noticed to traverse the pleural cavity while the tracing was normal. CVC was thus removed consequent to which bleeding from each puncture site was noticed, that were secured surgically.

  6. Hollow glass for insulating layers (United States)

    Merticaru, Andreea R.; Moagar-Poladian, Gabriel


    Common porous materials, some of which will be considered in the chapters of this book, include concrete, paper, ceramics, clays, porous semiconductors, chromotography materials, and natural materials like coral, bone, sponges, rocks and shells. Porous materials can also be reactive, such as in charcoal gasification, acid rock dissolution, catalyst deactivation and concrete. This study continues the investigations about the properties of, so-called, hollow glass. In this paper is presented a computer simulation approach in which the thermo-mechanical behavior of a 3D microstructure is directly computed. In this paper a computer modeling approach of porous glass is presented. One way to test the accuracy of the reconstructed microstructures is to computed their physical properties and compare to experimental measurement on equivalent systems. In this view, we imagine a new type of porous type of glass designed as buffer layer in multilayered printed boards in ICs. Our glass is a variable material with a variable pore size and surface area. The porosity could be tailored early from the deposition phases that permitting us to keep in a reasonable balance the dielectric constant and thermal conductivity.

  7. Analysis of the NovoTwist pen needle in comparison with conventional screw-thread needles. (United States)

    Aye, Tandy


    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.

  8. Winging of the scapula: An unusual complication of needle thoracocentesis. (United States)

    Faruqi, S; Raychaudhuri, C; Thirumaran, M; Blaxill, P


    Needle thoracocentesis is a common interventional procedure and is generally considered to be safe. Major complications associated with this procedure are uncommon. Here we describe a rare instance of winging of the scapula following needle thoracocentesis.

  9. The Needling Technique and Clinical Application of Point Zhibian

    Institute of Scientific and Technical Information of China (English)



    @@ The Needling Technique The patient is asked to lie in a lateral or prone position. A No. 28 filiform needle of 3 cun is inserted perpendicularly into the point Zhibian (BL 54), with the direction of the needle tip varying according to the different conditions of the diseases. The needle can be directed in three directions, the first along the sciatic nerve; the second pointing to the genitals; and the third pointing to the anus. The reinforcing,reducing, or even needling manipulation can be used,and the needling depth can be deep or superficial.The needling can also be applied in combination with the warm-needle, cupping, and point-injection.

  10. Preparation of (non-)aqueous dispersins of colloidal boehmite needles

    NARCIS (Netherlands)

    Buining, P.A.; Pathmamanoharan, C.; Philipse, A.P.; Lekkerkerker, H.N.W.


    A novel hydrothermal alkoxide method is presented for the preparation of stable, aqueousdispersions of fairly monodisperse, charged colloidal boehmite needles. A polymer coating procedure for the needles is described which leads to sterically stabilized dispersions in organic solvents.

  11. Prevention of dialysis catheter-related sepsis with a citrate-taurolidine-containing lock solution.

    NARCIS (Netherlands)

    M.G.H. Betjes (Michiel); M. Agteren (Madelon)


    textabstractBACKGROUND: The use of haemodialysis catheters is complicated by catheter-related sepsis. Intraluminal colonization of the catheter with bacteria is important in the pathogenesis of catheter-related sepsis. The use of a catheter lock solution containing the antimicrobia

  12. Needle Path Planning for Autonomous Robotic Surgical Suturing. (United States)

    Jackson, Russell C; Cavuşoğlu, M Cenk


    This paper develops a path plan for suture needles used with solid tissue volumes in endoscopic surgery. The path trajectory is based on the best practices that are used by surgeons. The path attempts to minimize the interaction forces between the tissue and the needle. Using surgical guides as a basis, two different techniques for driving a suture needle are developed. The two techniques are compared in hardware experiments by robotically driving the suture needle using both of the motion plans.

  13. [Biodegradable catheters and urinary stents. When? (United States)

    Soria, F; Morcillo, E; López de Alda, A; Pastor, T; Sánchez-Margallo, F M


    One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a

  14. Catheter sepsis due to Staphylococcus epidermidis during parenteral nutrition. (United States)

    Sitges-Serra, A; Puig, P; Jaurrieta, E; Garau, J; Alastrue, A; Sitges-Creus, A


    Staphylococcus epidermidis is a pathogenic organism with increasing importance in total parenteral nutrition therapy. Strict asepsis during catheter insertion prolongs the interval free from Staphylococcus epidermidis infection. Staphylococcus epidermidis colonizes the catheter after migrating from the skin. For protection, we advise a long subcutaneous tunnel for all catheters that are to be indwelling for longer than three weeks. Prompt recatheterization of a patient with Staphylococcus epidermidis sepsis can result in hematogenous seeding of the new catheter and persistence of the infection. Catheter related Staphylococcus epidermidis sepsis has subsided after catheter withdrawal, and there is no need for antibiotic therapy provided that other prosthetic materials are not placed in the vascular tree. Immunologic status of the patients is not related to the frequency or severity of Staphylococcus epidermidis infections, or both.

  15. A prototype catheter designed for ultraviolet C disinfection

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja


    Background Disinfection of the intraluminal space of single-lumen polymer tubes can be obtained by ultraviolet C (UVC) light exposure from an external light source. In existing catheters UVC disinfection is hampered by the design of the catheter hub and tube connector. Aim To demonstrate...... that it is possible to design a single-lumen catheter with a hub, tube connector and tube parts that can be UVC-disinfected throughout its entire lumen. Methods Two single-lumen catheters were designed: one control and one for UVC exposure. They were contaminated with Pseudomonas aeruginosa (104–105 cfu/mL) before...... UVC light exposure, sampling and plate counting. Findings Two minutes of UVC exposure was sufficient to obtain 4 log10 disinfection for the full-length prototype catheter. This exposure corresponds to ∼40 mJ/cm2 at the catheter tip and indicates that even shorter exposure times can be achieved...

  16. Penile strangulation and necrosis due to condom catheter. (United States)

    Özkan, Heval S; İrkoren, Saime; Sivrioğlu, Nazan


    Condom catheters are often used in the management of male urinary incontinence, and are considered to be safe. As condom catheters are placed on the male genitalia, sometimes adequate care is not taken after placement owing to poor medical care of debilitated patients and feelings of embarrassment and shame. Similarly, sometimes the correct size of penile sheath is not used. Strangulation of penis due to condom catheter is a rare condition; only few such cases have been reported in the literature. Proper application and routine care of condom catheters are important in preventing this devastating complication especially in a neurologically debilitated population. We present a case of penile necrosis due to condom catheter. We will also discuss proper catheter care and treatment of possible complications.

  17. Conceptual Design and Procedure for an Autonomous Intramyocardial Injection Catheter. (United States)

    Cheng, Weyland; Law, Peter


    This article discusses existing catheter systems and proposes a conceptual design and procedure for an autonomous cellinjection catheter for the purpose of transferring committed myogenic or undifferentiated stem cells into the infarct boundary zones of the left ventricle. Operation of existing catheters used for cell delivery is far from optimal. Commercial injection catheters available are hand-held devices operated manually by means of tip deflection and torque capabilities. Interventionists require a hefty learning curve and often encounter difficulties in catheter stabilization and infarct detection, resulting in lengthy operation times and non-precise injections. We examined current technologies and proposed a design incorporating robotic positional control, feedback signals, and an adaptable operational sequence to overcome these problems. The design provides the basis for the construction of a robotic catheter that is able to autonomously assist the physician in transferring myogenic cells to the left ventricle infarct boundary zones.

  18. Risk of infection after placement of an extraventricular drainage catheter

    Directory of Open Access Journals (Sweden)

    Novak Vesna


    Full Text Available Introduction. The occurrence of infection after the placement of an extraventricular drainage (EVD catheter can be a very serious problem in neurosurgery. Objective. The aim of this study was to confirm that the use of special catheters with impregnated antibiotics decreased the percentage of infection. Methods. The prospective study conducted at the Clinic of Neurosurgery in Niš in the period 2006-2009 is presented. Group 1 comprised of 43 patients in whom a commonly used system for EVD was applied. Group 2 comprised of 39 patients in whom the Rifampycin and Clindamycin impregnated EVD catheters were applied (Bactiseal catheters. Results. In Group 1 infection occurred in nine patients, mainly caused by bacteria of Staphylococcus genus. In Group 2 only two patients developed infections caused by Acinetobacter. Conclusion. The use of Bactiseal EVD catheters considerably decreased the percentage of infection occurrence with prolonged EVD catheter drainage period.

  19. Central venous catheter placement: where is the tip? (United States)

    Ibrahim, George M


    The insertion of central venous catheters is a common bedside procedure performed in intensive care units. Here, we present a case of an 82-year-old man who underwent insertion of a central venous catheter in the internal jugular vein without perceived complications. Postprocedural radiographs showed rostral migration of the catheter, and computed tomography performed coincidentally showed cannulation of the jugular bulb at the level of the jugular foramen. To our knowledge, this is the first report to document migration of a central venous catheter from the internal jugular vein into the dural sinuses, as confirmed by computed tomography. The case highlights the importance of acquiring postprocedural radiographs for all insertions of central venous catheters to confirm catheter placement.

  20. Preparation of hollow spherical carbon nanocages

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.-K.; Kang, H. Y.; Hong, C.-I; Huang, C.-H.; Chang, F.-C.; Wang, H. Paul, E-mail: [National Cheng Kung University, Department of Environmental Engineering, Taiwan (China)


    This study presents a new and simple method for the synthesis of hollow carbon spheres possessing nanocage sizes of 7.1, 14, and 20 nm in diameter. The core-shell (i.e., Cu-C) nanoparticles prepared by carbonization of the Cu{sup 2+}-cyclodextrin (CD) complexes at 573 K for 2 h was etched with HCl (6N) to yield the hollow carbon spheres. The carbon-shell of the hollow carbon nanospheres, which consisted of mainly diamond-like and graphite carbons, is not perturbed during etching. In addition to the nanocages, the hollow carbon nanospheres also possess micropores with an opening of 0.45 nm, allowing small molecules to diffuse in and out through the carbon-shell. Many elements (such as Zn{sup 2+} or Cu{sup 2+}) can therefore be filled into the nanocages of the hollow carbon nanospheres. With these unique properties, for instance, designable active species such as Cu and ZnO encapsulated in the carbon-shell can act as Cu-ZnO-C yolk-shell nanoreactors which are found very effective in the catalytic decomposition of methanol.

  1. Comparative Study of Wear Resistance of Sewing Needles

    Institute of Scientific and Technical Information of China (English)

    FEI Dong-ye; ZHU Shi-gen


    Poor wearability is the most serious problem of domestic sewing needle, which is the main reason for their short service lives. The influences of needle materials,microstructures and manufacturing technologies on the wear resistance are analyzed in comparison with foreign sewing needles. A series of suitable measures are proposed to improve the wear resistance.

  2. Robotic needle steering: design, modeling, planning, and image guidance

    NARCIS (Netherlands)

    Cowan, Noah J.; Goldberg, Ken; Chirikjian, Gregory S.; Fichtinger, Gabor; Alterovitz, Ron; Reed, Kyle B.; Kallem, Vinutha; Park, Wooram; Misra, Sarthak; Okamura, Allison M.; Rosen, Jacob; Hannaford, Blake; Satava, Richard M.


    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 m

  3. Mechanics of Flexible Needles Robotically Steered through Soft Tissue

    NARCIS (Netherlands)

    Misra, S.; Reed, K.B.; Schafer, B.W.; Ramesh, K.T.; Okamura, A.M.


    The tip asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. This enables robotic needle steering, which can be used in medical procedures to reach subsurface targets inaccessible by straight-line trajectories. However, accurate path planning

  4. Method for the production of fabricated hollow microspheroids

    Energy Technology Data Exchange (ETDEWEB)

    Wickramanayake, Shan; Luebke, David R.


    The method relates to the fabrication of a polymer microspheres comprised of an asymmetric layer surrounding a hollow interior. The fabricated hollow microsphere is generated from a nascent hollow microsphere comprised of an inner core of core fluid surrounded by a dope layer of polymer dope, where the thickness of the dope layer is at least 10% and less than 50% of the diameter of the inner core. The nascent hollow microsphere is exposed to a gaseous environment, generating a vitrified hollow microsphere, which is subsequently immersed in a coagulation bath. Solvent exchange produces a fabricated hollow microsphere comprised of a densified outer skin surrounding a macroporous inner layer, which surrounds a hollow interior. In an embodiment, the polymer is a polyimide or a polyamide-imide, and the non-solvent in the core fluid and the coagulation bath is water. The fabricated hollow microspheres are particularly suited as solvent supports for gas separation processes.

  5. Bubble Growth and Detachment from a Needle (United States)

    Shusser, Michael; Rambod, Edmond; Gharib, Morteza


    The release of bubbles from an underwater nozzle or orifice occurs in large number of applications, such as perforated plate columns, blood oxygenators and various methods of water treatment. It is also a widely used method in laboratory research on multiphase flow and acoustics for generating small bubbles in a controlled fashion. We studied experimentally the growth and pinch-off of air bubbles released from a submerged needle into a quiescent liquid or a liquid flowing parallel to the needle. Micron-sized bubbles were generated by an air-liquid dispenser. High-speed imaging was performed to study the formation and detachment of bubbles from the tip of the needle. The impact of the needle diameter was investigated and the size and number of produced bubbles were assessed for different flow rates of air and for different velocities of the imposed upward liquid flow. The results were compared with available theoretical models and numerical computations. The existence of a critical gas flow rate and two regimes of bubble growth were verified.

  6. Buffon Needle Problem Application to Space Exploration

    CERN Document Server

    Sedelnikov, A V


    In this article the possibility of application of classical Buffon needle problem to the investigation of orientation engine firing problem has been investigated. Such an approach makes it possible to get a reliable EP of this undesired event without using a more complicated analysis.

  7. Relationship between needle phobia and dental anxiety

    NARCIS (Netherlands)

    Majstorovic, M.; Veerkamp, J.S.J.


    Purpose: This cross-sectional study aimed to explain the nature of needle phobia and its relationship in dental phobic children with evidence on age-related differences. Methods: The study used 2,865 patients (52% boys, 48% girls), 4 to 11 years old (mean=7.18 years). The patient sample included ran

  8. Biocompatible 3D printed magnetic micro needles

    KAUST Repository

    Kavaldzhiev, Mincho


    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.

  9. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age. (United States)

    Kuang, Yuan Wen; Wen, Da Zhi; Zhou, Guoyi; Liu, Shi Zhong


    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.

  10. Transmission properties of hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.


    Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers.......Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers....

  11. Malignant pleural effusion in the presence of trapped lung. Five-year experience of PleurX tunnelled catheters. (United States)

    Efthymiou, Christopher Andrew; Masudi, Tahir; Thorpe, James Andrew Charles; Papagiannopoulos, Kostas


    Malignant pleural effusions in the presence of trapped lung remain notoriously difficult to treat. Various methods exist ranging from minimally invasive procedures including repeated needle thoracocentesis to the need for a formal surgical procedure such as placement of a pleuroperitoneal shunt and even thoracotomy and decortication. Controversy exists as to what is the optimum treatment for this condition. Any planned treatment should balance the therapeutic benefit provided against convalesce for a disease with a limited life expectancy. Patients should not spend a significant proportion of their remaining life span recovering from palliative procedures. In a series of patients with malignant pleural effusion the medial survival time was 20 weeks, with 30 days and 1 year mortality rates of 12.8% and 83.6%, respectively. We describe our five-year experience with the use of indwelling PleurX catheters in patients with malignant pleural effusions in the presence of confirmed trapped lung on radiological or VATS investigation. Patient health related quality of life was investigated by telephone questionnaire. The parameters analysed were symptomatic relief, mobility and ease of management following insertion. One hundred and sixteen patients underwent PleurX catheter insertion by a single operator, 48 questionnaires were completed. Of the 48 cases analysed, improvement in all three quality of life indices was recorded following catheter insertion. Ease of mobility was recorded as moderately satisfied and very satisfied in 50% and 15% of patients, respectively. Symptomatic improvement was found to have been increased with 42% and 6% of patients responding to moderately satisfied and very satisfied, respectively. Ease of management was recorded as 'slightly satisfied' and moderately satisfied in 50% and 33% of patients, respectively, demonstrating a high satisfaction index in patients with chronic progressively debilitating malignancies. Complications were either

  12. Pulse dispersion in hollow optical waveguides (United States)

    Ben-David, M.; Ilev, Ilko K.; Waynant, Ronald W.; Gannot, Israel


    A study of laser (near- and mid-infrared) pulse dispersion in hollow waveguides is presented. We developed an analytical model to describe the pulse dispersion in hollow waveguides and compared our theoretical calculations with measurements done by us and also by two other groups. The pulse dispersion was experimentally measured for a short Q-switched Er:YAG laser in the nanosecond range and for femtosecond Ti:sapphire laser pulses transmitted by hollow optical waveguides. For analytical calculation of the pulse dispersion in these waveguides, a refined ray tracing program was developed. This approach took into account roughness of the internal reflecting and refracting inner layers. A comparison analysis between the measurements and calculations conducted at identical parameters demonstrates good correlation between theoretical and experimental results.

  13. Sheet Plasma Produced by Hollow Cathode Discharge

    Institute of Scientific and Technical Information of China (English)

    张龙; 张厚先; 杨宣宗; 冯春华; 乔宾; 王龙


    A sheet plasma is produced by a hollow cathode discharge under an axial magnetic field.The plasma is about 40cm in length,4 cm in width and 1cm in thickness.The electron density is about 108cm-3.The hollow cathode is made to be shallow with a large opening,which is different from the ordinary deep hollow cathode.A Langmuir probe is used to detect the plasma.The electron density and the spatial distribution of the plasma change when voltage,pressure and the magnetic field vary.A peak and a data fluctuation at about 200 G-300 G are observed in the variation of electron density(or thickness of the sheet plasma)with the magnetic field.Our work will be helpful in characterizing the sheet plasma and will make the production of dense sheet plasma more controllable.

  14. Hollow glass waveguides for broadband infrared transmission. (United States)

    Abel, T; Hirsch, J; Harrington, J A


    Broadband hollow glass waveguides have been fabricated with losses as low as 0.15 dB/m at 10.6 microm. We make these hollow glass waveguides by coating the inside of polyimide-coated silica-glass tubing with a metallic layer followed by a thin dielectric coating of a metal halide. The bore sizes of the guides range from 320 to 700 microm, and we have made lengths as long as 3 m. The bending radii of the waveguides are less than 5 cm for bore sizes less than 500 microm. We have used these waveguides to deliver greater than 80 W of CO(2) laser power and 5 W of Er:YAG laser power. The hollow glass guides are inexpensive, robust, and quite flexible and therefore a good infrared fiber for power and sensor applications.

  15. Generation of a hollow laser beam by a multimode fiber

    Institute of Scientific and Technical Information of China (English)

    Hongyu Ma; Huadong Cheng; Wenzhuo Zhang; Liang Liu; Yuzhu Wang


    A simple method to generate a hollow laser beam by multimode fiber is reported. A dark hollow laser beam is generated from a multimode fiber and the dependence of the output beam profile on the incident angle of laser beam is analyzed. The results show that this hollow laser beam can be used to trap and guide cold atoms.

  16. Adiabatic Rearrangement of Hollow PV Towers

    Directory of Open Access Journals (Sweden)

    Eric A Hendricks


    Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

  17. Scaffold Characteristics for Functional Hollow Organ Regeneration

    Directory of Open Access Journals (Sweden)

    Daniel Eberli


    Full Text Available Many medical conditions require surgical reconstruction of hollow organs. Tissue engineering of organs and tissues is a promising new technique without harvest site morbidity. An ideal biomaterial should be biocompatible, support tissue formation and provide adequate structural support. It should degrade gradually and provide an environment allowing for cell-cell interaction, adhesion, proliferation, migration, and differentiation. Although tissue formation is feasible, functionality has never been demonstrated. Mainly the lack of proper innervation and vascularisation are hindering contractility and normal function. In this chapter we critically review the current state of engineering hollow organs with a special focus on innervation and vascularisation.

  18. Hollow electrode loose plate SOFC design

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, B.C.; Dongen, B.A.M. van; Monaster, G.A. [Seed Capital Investments B.V., Utrecht (Netherlands); Roosmalen, J.A.M. van; Plaisier, K.H.; Schoonman, J. [Delft Univ. of Technology (Netherlands). Lab. for Applied Inorganic Chemistry


    A novel planar SOFC design is presented, based on the loose stacking of hollow electrode elements, conventional plate type electrolytes and interconnectors. This facilitates free thermal expansion during operation, and thermal cycling, thereby significantly improving prospects for reliable SOFC operation in power generation practice. Each individual element only consists of one material, eliminating the need for sealing and for matching thermal expansion coefficients of fuel cell components. Application of hollow electrodes results in an inherent manifolding of the gas streams eliminating the need for seals at the fuel cell stack itself. The design has been tested at laboratory scale and a small working prototype fuel cell has been successfully tested.

  19. Improved method for the detection of catheter colonization and catheter-related bacteremia in newborns. (United States)

    Martín-Rabadán, P; Pérez-García, F; Zamora Flores, E; Nisa, E S; Guembe, M; Bouza, E


    Accurate diagnosis of catheter-related bloodstream infection (CRBSI) is mandatory for hospital infection control. Peripherally inserted central venous catheters (PICCs) are widely used in intensive care units, but studies about procedures for detection of colonization are scarce in neonates. We sequentially processed 372 PICCs by 2 methods, first by the standard roll-plate (RP) technique and then by rubbing catheters on a blood agar plate after being longitudinally split (LS). With both techniques, we detected 133 colonized PICCs. Ninety-four events of CRBSI were diagnosed. The sensitivity, specificity, positive predictive value, and negative predictive value for detection of CRBSI were 58.5%, 92.8%, 73.3%, and 86.9%, respectively, for RP technique and 96.8%, 88.5%, 74.0%, and 98.8%, respectively, for LS technique. The LS technique increased the proportion of detected CRBSI by 38.3%. Neonatal PICC tips should be cultured after cutting them open. This technique is simple and sensitive to detect catheter colonization and also to diagnose CRBSI.

  20. The Hollow-Face Illusion in Infancy: Do Infants See a Screen Based Rotating Hollow Mask as Hollow?

    Directory of Open Access Journals (Sweden)

    Aki Tsuruhara


    Full Text Available We investigated whether infants experience the hollow-face illusion using a screen-based presentation of a rotating hollow mask. In experiment 1 we examined preferential looking between rotating convex and concave faces. Adults looked more at the concave—illusory convex—face which appears to counter rotate. Infants of 7- to 8-month-old infants preferred the convex face, and 5- to 6-month-olds showed no preference. While older infants discriminate, their preference differed from that of adults possibly because they don't experience the illusion or counter rotation. In experiment 2 we tested preference in 7- to 8-month-olds for angled convex and concave static faces both before and after habituation to the stimuli shown in experiment 1. The infants showed a novelty preference for the static shape opposite to the habituation stimulus, together with a general preference for the static convex face. This shows that they discriminate between convex and concave faces and that habituation to either transfers across a change in view. Seven- to eight-month-olds have been shown to discriminate direction of rigid rotation on the basis of perspective changes. Our results suggest that this, perhaps together with a weaker bias to perceive faces as convex, allows these infants to see the screen-based hollow face as hollow even though adults perceive it as convex.

  1. Totally implantable venous catheters for chemotherapy: experience in 500 patients

    Directory of Open Access Journals (Sweden)

    Nelson Wolosker

    Full Text Available CONTEXT: Totally implantable devices are increasingly being utilized for chemotherapy treatment of oncological patients, although few studies have been done in our environment to analyze the results obtained from the implantation and utilization of such catheters. OBJECTIVE: To study the results obtained from the implantation of totally implantable catheters in patients submitted to chemotherapy. TYPE OF STUDY: Prospective. SETTING: Hospital do Câncer A.C. Camargo, São Paulo, Brazil. METHODS: 519 totally implantable catheters were placed in 500 patients submitted to chemotherapy, with preference for the use of the right external jugular vein. Evaluations were made of the early and late-stage complications and patient evolution until removal of the device, death or the end of the treatment. RESULTS: The prospective analysis showed an average duration of 353 days for the catheters. There were 427 (82.2% catheters with no complications. Among the early complications observed, there were 15 pathway hematomas, 8 cases of thrombophlebitis of the distal stump of the external jugular vein and one case of pocket infection. Among the late-stage complications observed, there were 43 infectious complications (0.23/1000 days of catheter use, 11 obstructions (0.06/1000 days of catheter use and 14 cases of deep vein thrombosis (0.07/1000 days of catheter use. Removal of 101 catheters was performed: 35 due to complications and 66 upon terminating the treatment. A total of 240 patients died while the catheter was functioning and 178 patients are still making use of the catheter. CONCLUSION: The low rate of complications obtained in this study confirms the safety and convenience of the use of totally implantable accesses in patients undergoing prolonged chemotherapy regimes.


    Directory of Open Access Journals (Sweden)

    Márcio Viera


    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.

  3. Torsional dynamics of steerable needles: modeling and fluoroscopic guidance. (United States)

    Swensen, John P; Lin, MingDe; Okamura, Allison M; Cowan, Noah J


    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 semitransparent 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.

  4. An Exploration of the Needling Depth in Acupuncture: The Safe Needling Depth and the Needling Depth of Clinical Efficacy

    Directory of Open Access Journals (Sweden)

    Jaung-Geng Lin


    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.

  5. Fabrication of AlN/BN bishell hollow nanofibers by electrospinning and atomic layer deposition

    Directory of Open Access Journals (Sweden)

    Ali Haider


    Full Text Available Aluminum nitride (AlN/boron nitride (BN bishell hollow nanofibers (HNFs have been fabricated by successive atomic layer deposition (ALD of AlN and sequential chemical vapor deposition (CVD of BN on electrospun polymeric nanofibrous template. A four-step fabrication process was utilized: (i fabrication of polymeric (nylon 6,6 nanofibers via electrospinning, (ii hollow cathode plasma-assisted ALD of AlN at 100 °C onto electrospun polymeric nanofibers, (iii calcination at 500 °C for 2 h in order to remove the polymeric template, and (iv sequential CVD growth of BN at 450 °C. AlN/BN HNFs have been characterized for their chemical composition, surface morphology, crystal structure, and internal nanostructure using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction. Measurements confirmed the presence of crystalline hexagonal BN and AlN within the three dimensional (3D network of bishell HNFs with relatively low impurity content. In contrast to the smooth surface of the inner AlN layer, outer BN coating showed a highly rough 3D morphology in the form of BN nano-needle crystallites. It is shown that the combination of electrospinning and plasma-assisted low-temperature ALD/CVD can produce highly controlled multi-layered bishell nitride ceramic hollow nanostructures. While electrospinning enables easy fabrication of nanofibrous template, self-limiting reactions of plasma-assisted ALD and sequential CVD provide control over the wall thicknesses of AlN and BN layers with sub-nanometer accuracy.

  6. Preprocedural ultrasound examination versus manual palpation for thoracic epidural catheter insertion

    Directory of Open Access Journals (Sweden)

    Ahmed M Hasanin


    Conclusion: Preprocedural ultrasound imaging increased the incidence of first pass success in thoracic epidural catheter insertion and reduced the catheter insertion time compared to manual palpation method.

  7. Duration and Adverse Events of Non-cuffed Catheter in Patients With Hemodialysis (United States)


    Renal Failure Chronic Requiring Hemodialysis; Central Venous Catheterization; Inadequate Hemodialysis Blood Flow; Venous Stenosis; Venous Thrombosis; Infection Due to Central Venous Catheter; Central Venous Catheter Thrombosis

  8. Safety and efficacy of catheter-directed thrombolysis

    DEFF Research Database (Denmark)

    Bækgaard, N; Klitfod, Lotte; Broholm, R


    To describe the background for--and mechanism of--catheter-directed thrombolysis (CDT) for iliofemoral deep venous thrombosis (DVT) accessed via the popliteal vein. Focus is on safety and efficacy.......To describe the background for--and mechanism of--catheter-directed thrombolysis (CDT) for iliofemoral deep venous thrombosis (DVT) accessed via the popliteal vein. Focus is on safety and efficacy....

  9. A magnetic-resonance-imaging-compatible remote catheter navigation system. (United States)

    Tavallaei, Mohammad Ali; Thakur, Yogesh; Haider, Syed; Drangova, Maria


    A remote catheter navigation system compatible with magnetic resonance imaging (MRI) has been developed to facilitate MRI-guided catheterization procedures. The interventionalist's conventional motions (axial motion and rotation) on an input catheter - acting as the master - are measured by a pair of optical encoders, and a custom embedded system relays the motions to a pair of ultrasonic motors. The ultrasonic motors drive the patient catheter (slave) within the MRI scanner, replicating the motion of the input catheter. The performance of the remote catheter navigation system was evaluated in terms of accuracy and delay of motion replication outside and within the bore of the magnet. While inside the scanner bore, motion accuracy was characterized during the acquisition of frequently used imaging sequences, including real-time gradient echo. The effect of the catheter navigation system on image signal-to-noise ratio (SNR) was also evaluated. The results show that the master-slave system has a maximum time delay of 41 ± 21 ms in replicating motion; an absolute value error of 2 ± 2° was measured for radial catheter motion replication over 360° and 1.0 ± 0.8 mm in axial catheter motion replication over 100 mm of travel. The worst-case SNR drop was observed to be 2.5%.

  10. Unusual migration of ventriculo peritoneal distal catheter into vagina

    Directory of Open Access Journals (Sweden)

    Sghavamedin Tavallaee


    Full Text Available VP shunt is one of the most popular methods for ICP reduction and treatment of hydrocephalus. Various complications of this method are not uncommon such as shunt malfunction, infection and unusual migration of distal catheter. I present a case of migration of the peritoneal catheter out of the vagina.

  11. 21 CFR 870.1350 - Catheter balloon repair kit. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Catheter balloon repair kit. 870.1350 Section 870... repair kit. (a) Identification. A catheter balloon repair kit is a device used to repair or replace the... effect the repair or replacement. (b) Classification. Class III (premarket approval). (c) Date PMA...

  12. 21 CFR 870.1290 - Steerable catheter control system. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Steerable catheter control system. 870.1290 Section 870.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification....

  13. Diagnosis and Rescue of a Kinked Pulmonary Artery Catheter

    Directory of Open Access Journals (Sweden)

    Nicolas J. Mouawad


    Full Text Available Invasive hemodynamic monitoring with a pulmonary catheter has been relatively routine in cardiovascular and complex surgical operations as well as in the management of critical illnesses. However, due to multiple potential complications and its invasive nature, its use has decreased over the years and less invasive methods such as transesophageal echocardiography and hemodynamic sensors have gained widespread favor. Unlike these less invasive forms of hemodynamic monitoring, pulmonary artery catheters require an advanced understanding of cardiopulmonary physiology, anatomy, and the potential for complications in order to properly place, manage, and interpret the device. We describe a case wherein significant resistance was encountered during multiple unsuccessful attempts at removing a patient’s catheter secondary to kinking and twisting of the catheter tip. These attempts to remove the catheter serve to demonstrate potential rescue options for such a situation. Ultimately, successful removal of the catheter was accomplished by simultaneous catheter retraction and sheath advancement while gently pulling both objects from the cannulation site. In addition to being skilled in catheter placement, it is imperative that providers comprehend the risks and complications of this invasive monitoring tool.

  14. Diagnosis of intra vascular catheter-related infection. (United States)

    Cicalini, S; Palmieri, F; Noto, P; Boumis, E; Petrosillo, N


    The use of central vascular catheters (CVC) is associated with a substantial number of complications, amongst which infections predominate. A diagnosis of CVC-related infection usually requires catheter removal for culture. Semiquantitative (roll-plate method) and quantitative methods (flush, vortex, centrifugation or sonication methods) are the most reliable diagnostic methodologies requiring catheter removal, because of their greater specificity. The roll-plate method is the simplest and most commonly used technique. This method only samples the external surface of the catheter, and is particularly indicated for recently inserted catheters in which extraluminal colonisation is the primary mechanism of infection. Luminal culture techniques, such as the quantitative methods, may be more relevant for catheters that have been in place for a long period of time. However, in up to 85% of removed CVC the culture is negative, and other diagnostic techniques that do not require catheter removal have been proposed, including paired quantitative blood cultures, endoluminal brushing, and differential time to positivity (DTP) of paired blood cultures. DTP, that compares the time to positivity for qualitative cultures of blood samples simultaneously drawn from the CVC and a peripheral vein, appears to be the most reliable in the routine clinical practice since many hospitals use automatic devices for qualitative blood culture positivity detection. More recently catheter-sparing direct diagnostic methods, which include Gram stain and acridin-orange leucocyte cytospin (AOLC) test, appeared to be especially useful because of the rapidity of results and the ability to distinguish different microorganisms, allowing early targeted antimicrobial therapy.

  15. Percutaneous transhepatic cholangiography using special needle

    Energy Technology Data Exchange (ETDEWEB)

    Auh, Yong Ho [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    Using the special needle (22 Gauze, 17 cm long, flexible needle) percutaneous transhepatic cholangiography were performed in 23 cases at Seoul National University Hospital during the period from July 1973 to August 1974. The results were as follows:1. Successful cholangiograms are obtained in 20 cases among the total of 23 cases. The 3 cases of the unsuccessful are two cases of sclerosing cholangitis and one case of hepatoma. 2. Average attempts of puncture in successful care are 3. It was not necessary to puncture more than 6 times to visualize biliary tree in dilated biliary tree. 3. Lateral approach (midaxillary line and 8th or 9th intercostal space) was used. The advantage of this method was briefly discussed. 4. Over all complication are occurred in 6 cases. 3 cases: transient fever 1 case: bile leakage without peritonitis 1 case: local peritonitis probably due to bile leakage 1 case: septicemia (the organism can not be detected even after blood culture)

  16. Galvanic Synthesis of Hollow Gold Nanoshells (United States)


    pulses in the NIR.2 The advantage of hollow nanoshells over solid gold (Au) or silver (Ag) nanoparticles , or alloys thereof,3 is that the...Karna SP. Synthesis of gold and silver nanoparticles and characterization of structural, optical, and electronic properties. Aberdeen Proving Ground...

  17. Hollow-atom probing of surfaces

    NARCIS (Netherlands)

    Limburg, J.


    This paper discusses the mechanisms governing the formation and decay of hollow atoms in front of (semi) conducting and insulating surfaces. First, the primary neutralization of the highly charged ions is treated in terms of the classical overbarrier model. Different views are presented. Then the mo

  18. Template engaged synthesis of hollow ceria-based composites (United States)

    Chen, Guozhu; Rosei, Federico; Ma, Dongling


    Hollow ceria-based composites, which consist of noble metal nanoparticles or metal oxides as a secondary component, are being studied extensively for potential applications in heterogeneous catalysis. This is due to their unique features, which exhibit the advantages of a hollow structure (e.g. high surface area and low weight), and also integrate the properties of ceria and noble metals/metal oxides. More importantly, the synergistic effect between constituents in hollow ceria-based composites has been demonstrated in various catalytic reactions. In this feature article, we summarize the state-of-the-art in the synthesis of hollow ceria-based composites, including traditional hard-templates and more recently, sacrificial-template engaged strategies, highlighting the key role of selected templates in the formation of hollow composites. In addition, the catalytic applications of hollow ceria-based composites are briefly surveyed. Finally, challenges and perspectives on future advances of hollow ceria-based composites are outlined.

  19. A retractable barb needle for drug darts

    Directory of Open Access Journals (Sweden)

    G.L. van Rooyen


    Full Text Available The mechanism and action of a new retractable barbneedle for drug darts are described. This dart needle is particularly successful in obviating unnecessary flight reactions andtrauma in darted animals, and facilitates the complete injection of the drug dose before the barb is retracted and the dart is dislogded from the animal. The whole process is completed within a few seconds and the expended dart can usually be retrieved in the immediate vicinity where the animal was darted.

  20. Extinction by the long dielectric needles

    CERN Document Server

    Cherkas, Nadejda L


    Electromagnetic wave extinction by the very long but finite dielectric needle is compared with that by the infinite dielectric cylinder for an oblique incidence of the electromagnetic wave. It is shown that the renormalized Hankel functions without the logarithmic terms should be used for the calculation of the extinction per unit length of the infinite dielectric cylinder to apply it for extinction calculations by the finite dielectric cylinder.

  1. New tools in diagnosing catheter-related infections. (United States)

    Blot, F; Nitenberg, G; Brun-Buisson, C


    Clinical criteria alone are insufficient to allow a diagnosis of intravascular catheter-related sepsis (CRS). A definite diagnosis of CRS usually requires removal of the catheter for quantitative catheter tip culture. However, only about 15-25% of central venous catheters (CVC) removed because infection is suspected actually prove to be infected, and the diagnosis is always retrospective. Other diagnostic tests, such as differential quantitative blood cultures from samples taken simultaneously from the catheter and a peripheral vein, have been proposed to avoid unjustified removal of the catheter and the potential risks associated with the placement of a new catheter at a new site: a central-to-peripheral blood culture colony count ratio of 5:1 to 10:1 is considered indicative of CRS. Despite its high specificity, the latter diagnostic technique is not routinely used in clinical practice because of its complexity and cost. The measurement of the differential time to positivity between hub blood (taken from the catheter port) and peripheral blood cultures might be a reliable tool facilitating the diagnosis of CRS in situ. In an in vitro study, we found a strong relationship between the inoculum size of various microorganisms and the time to positivity of cultures. When the times to positivity of cultures of blood taken simultaneously from central and peripheral veins in patients with and without CRS were examined, we found that earlier positivity of central vs peripheral vein blood cultures was highly correlated with CRS. Using a cut-off value of +120 min, the "differential time to positivity" of the paired blood samples, defined as time to positivity of the peripheral blood minus that of the hub blood culture, had 91% specificity and 94% sensitivity for the diagnosis of CRS. This method may be coupled with other techniques that have high negative predictive value, such as skin cultures at the catheter exit site. This diagnostic test can be proposed for routine

  2. Percutaneous catheter use in newborn infants with parenteral nutrition. (United States)

    García del Río, M; Lastra-Sanchez, G; Martínez-Léon, M; Martínez-Valverde, A


    The well known negative effect of infection on nutrition causes the cycle 'infection-malnutrition-infection'. Prolonged parenteral nutrition requires central venous catheterization. Due to the possibility of 'catheter related sepsis' (CRS) catheters should be used correctly to avoid septic complications. A very high percentage of central venous catheters (CVC) removed because of presumed infections are not infected when culture is done. In some patients infections are successfully treated with antibiotics without catheter removal. Removal of the line is recommended when catheter-associated sepsis is suspected or proven, but not for the extremely ill preterm infant or when such removal may be impractical. A therapeutic protocol is suggested to avoid future canalizations in the neonate, sometimes in a critical situation. Current literature referring to CRS in the newborn infant is reviewed.

  3. An Effective Technique for Enhancing an Intrauterine Catheter Fetal Electrocardiogram

    Directory of Open Access Journals (Sweden)

    Holls III William M


    Full Text Available Physician can obtain fetal heart rate, electrophysiological information, and uterine contraction activity for determining fetal status from an intrauterine catheters electrocardiogram with the maternal electrocardiogram canceled. In addition, the intrauterine catheter would allow physicians to acquire fetal status with one non-invasive to the fetus biosensor as compared to invasive to the fetus scalp electrode and intrauterine pressure catheter used currently. A real-time maternal electrocardiogram cancellation technique of the intrauterine catheters electrocardiogram will be discussed along with an analysis for the methods effectiveness with synthesized and clinical data. The positive results from an original detailed subjective and objective analysis of synthesized and clinical data clearly indicate that the maternal electrocardiogram cancellation method was found to be effective. The resulting intrauterine catheters electrocardiogram from effectively canceling the maternal electrocardiogram could be used for determining fetal heart rate, fetal electrocardiogram electrophysiological information, and uterine contraction activity.

  4. Exploration of New Electroacupuncture Needle Material

    Directory of Open Access Journals (Sweden)

    Sanghun Lee


    Full Text Available Background. Electro Acupuncture (EA uses the acupuncture needle as an electrode to apply low-frequency stimulation. For its safe operation, it is essential to prevent any corrosion of the acupuncture needle. Objective. The aim of this study is to find an available material and determine the possibility of producing a standard EA needle that is biocompatible. Methods. Biocompatibility was tested by an MTT assay and cytotoxicity testing. Corrosion was observed with a scanning electron microscope (SEM after 0.5 mA, 60 min stimulation. The straightness was measured using a gap length of 100 mm, and tensile testing was performed by imposing a maximum tensile load. Results. Phosphor bronze, Ni coated SS304, were deemed inappropriate materials because of mild-to-moderate cytotoxicity and corrosion. Ti-6Al-4V and SS316 showed no cytotoxicity or corrosion. Ti-6Al-4V has a 70 times higher cost and 2.5 times lower conductivity than SS316. The results of both straightness and tensile testing confirmed that SS316 can be manufactured as a standard product. Conclusion. As a result, we confirmed that SS316 can be used a new EA electrode material. We hope that a further study of the maximum capacity of low-frequency stimulation using an SS316 for safe operation.

  5. Pulsed photoelectric field emission from needle cathodes

    CERN Document Server

    Hernandez-Garcia, C


    Experiments have been carried out to measure the current emitted by tungsten needles with 1-mu m tip radius operated up to 50 kV. This corresponds to electric fields in the order of 10 sup 9 to 10 sup 1 sup 0 V/m. The needles were illuminated with 10-ns laser pulses at 532, 355 and 266 nm. The laser intensity was varied from 10 sup 1 sup 0 to 10 sup 1 sup 2 W/m sup 2 , limited by damage to the needle tip. The observed quantum efficiency depends on the wavelength and the electric field, approaching unity at the highest electric fields when illuminated at 266 nm. Peak currents up to 100 mA were observed in nanosecond pulses, corresponding to an estimated brightness of 10 sup 1 sup 6 A/m sup 2 sr. Since the current is controlled by the laser intensity, with only a weak voltage dependence, these cathodes can be used for infrared and ultraviolet tabletop free-electron lasers and other applications that demand short electron-beam pulses with high brightness.

  6. Manually controlled steerable needle for MRI-guided percutaneous interventions. (United States)

    Henken, Kirsten R; Seevinck, Peter R; Dankelman, Jenny; van den Dobbelsteen, John J


    This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of the needle tip through manipulation of the handle. The steering mechanism is evaluated by recording needle deflection at constant steering angles. A steering angle of 20.3° results in a deflection of 9.1-13.3 mm in gelatin and 4.6-18.9 mm in porcine liver tissue at an insertion depth of 60 mm. Additionally, the possibility to control the needle path under MRI guidance is evaluated in a gelatin phantom. The needle can be steered to targets at different locations while starting from the same initial position and orientation under MRI guidance with generally available sequences. The steerable needle offers flexibility to the physician in control and choice of the needle path when navigating the needle toward the target position, which allows for optimization of individual treatment and may increase target accuracy.

  7. The effects of needle deformation during lumbar puncture

    Directory of Open Access Journals (Sweden)

    Hasan Hüseyin Özdemir


    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.

  8. The effects of needle deformation during lumbar puncture (United States)

    Özdemir, Hasan Hüseyin; Demir, Caner F.; Varol, Sefer; Arslan, Demet; Yıldız, Mustafa; Akil, Eşref


    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

  9. Comparison of heparin-coated and conventional split-tip hemodialysis catheters. (United States)

    Clark, Timothy W I; Jacobs, David; Charles, Hearns W; Kovacs, Sandor; Aquino, Theresa; Erinjeri, Joseph; Benstein, Judith A


    Catheter coatings have the potential to decrease infection and thrombosis in patients with chronic dialysis catheters. We report our midterm experience with a heparin-coated dialysis catheter. This retrospective, case-control study was approved by our Institutional Review Board. A total of 88 tunneled dialysis catheters were inserted over a 13-month period via the internal jugular vein. Thirty-eight uncoated split-tip catheters and 50 heparin-coated catheters were inserted. Primary catheter patency was compared between the two groups using the log rank test, with infection and/or thrombosis considered as catheter failures. Dialysis parameters during the first and last dialysis sessions, including pump speed, actual blood flow, and arterial port pressures, were compared using unpaired t-tests. Primary patency of the uncoated catheters was 86.0 +/- 6.5% at 30 days and 76.1 +/- 8.9% at 90 days. Primary patency of heparin-coated catheters was 92.0 +/- 6.2% at 30 days and 81.6 +/- 8.0% at 90 days (p = 0.87, log rank test). Infection requiring catheter removal occurred in four patients with uncoated catheters and two patients with heparin-coated catheters (p = 0.23). Catheter thrombosis requiring catheter replacement or thrombolysis occurred in one patient with an uncoated catheter and two patients with heparin-coated catheters (p = 0.9). No differences in catheter function during hemodialysis were seen between the two groups. In conclusion, the heparin-coated catheter did not show a significantly longer patency compared to the uncoated catheter. The flow characteristics of this device were comparable to those of the conventional uncoated catheter. A demonstrable benefit of the heparin-coated catheter in randomized trials is needed before a recommendation for routine implementation can be made.


    Directory of Open Access Journals (Sweden)

    Tameem Afroz


    Full Text Available BACKGROUND Prostate needle biopsies can pose a major diagnostic challenge when it comes to differentiating adenocarcinoma and its variants from its benign mimics. In needle biopsies, when the suspicious focus is small, morphological features may not suffice to differentiate it from its morphologic mimics like atrophy, basal cell hyperplasia, reactive inflammatory changes, seminal vesicles and adenosis. Immunohistochemical marker for basal cells, p63 and prostate cancer specific marker, Alpha-Methylacyl-CoA Racemase (AMACR help in overcoming such diagnostic dilemmas. MATERIALS AND METHODS We analysed 157 prostate core needle biopsies over a period of 2 years. Routine Hematoxylin and Eosin (H and E sections and immunohistochemical markers for basal cells (p63 and prostate cancer specific marker (AMACR were used. Prospective study was done on prostate needle core biopsies. Biopsy was done under ultrasound guidance with an 18-gauge needle. Biopsy was done in patients with raised serum PSA levels for exclusion of prostate carcinoma. RESULTS Over a period of two years, 157 prostate core needle biopsies were studied. 83 were benign lesions comprising 69 benign prostatic hyperplasias, five basal cell hyperplasias, four granulomatous lesions and three showed atrophic changes. Two biopsies morphologically resembled seminal vesicles. Prostate cancer specific marker, AMACR was negative in all, but two lesions. In these two lesions, it showed weak nonspecific staining. Basal cell marker p63 showed a continuous staining pattern highlighting the basal cells in all the 69 cases of benign prostatic hyperplasia, 5 cases of basal hyperplasia showed positivity in all the hyperplastic basal cells. In the two cases of seminal vesicles, it showed intense basal cell positivity. It showed a discontinuous pattern in two of the four granulomatous lesions and showed a weak, but a continuous staining pattern in the atrophic lesions. 74 were adenocarcinomas; the predominant

  11. Characteristics of Left-Right Spiral Hollow Cylindrical Roller

    Institute of Scientific and Technical Information of China (English)

    Liming Lu; Qiping Chen; Yujiang Qin


    Based on new rolling⁃sliding compound bearings, the wear between the one⁃way spiral hollow cylindrical roller and the ribs of the inner and outer ring of rolling⁃sliding compound bearings is reduced by innovational structural design. A new left⁃right spiral hollow cylindrical roller is proposed to replace the one⁃way spiral hollow cylindrical roller. The finite element analysis models of ordinary cylindrical rollers, one⁃way spiral hollow cylindrical rollers and left⁃right spiral hollow cylindrical rollers are respectively established by ABAQUS. The axial displacement of their center mass and the stress distribution of left⁃right spiral hollow cylindrical rollers are compared and analyzed. Theoretical study results show that this new left⁃right spiral hollow cylindrical roller not only inherits the advantages of one⁃way spiral hollow cylindrical rollers, but also avoids the axial offset and the serious wear of the one⁃way spiral hollow cylindrical roller. And the theory research conclusion is verified by the experiment. The left⁃right spiral hollow cylindrical roller has the advantages to overcome boundary stress concentration like logarithmic convex roller. The rolling⁃sliding compound bearings equipped with the new rollers can be better to adapt to the impact of vibration load.

  12. Usefulness of multifunctional gastrointestinal coil catheter for colorectal stent placement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Hyung; Shin, Ji Hoon; Kim, Jin Hyoung; Lim, Jin-Oh; Kim, Kyung Rae [Asan Medical Center, Radiology and Research Institute of Radiology, Seoul (Korea); Song, Ho-Young [Asan Medical Center - Radiology, Songpa-gu, Seoul (Korea); Park, In Kook [Dongguk University, Life Science, Seoul (Korea); Choi, Eugene K. [Weill Medical College of Cornell University, New York, NY (United States)


    The purpose of this study was to evaluate the usefulness of a multifunctional gastrointestinal coil catheter for stent placement in 98 patients with colorectal strictures. The catheter was used in 98 consecutive patients for stent placement in the rectum (n = 24), recto-sigmoid (n = 13), sigmoid (n = 38), descending (n = 6), transverse (n = 11), splenic flexure (n = 3), hepatic flexure (n = 2), and ascending (n = 1) colon. The catheter was made of a stainless steel coil (1.3 mm in inner diameter), a 0.4-mm nitinol wire, a polyolefin tube, and a hemostasis valve. Usefulness of the catheter was evaluated depending on whether the catheter could pass a stricture over a guide wire and whether measurement of the stricture length was possible. The passage of the catheter over a guide wire beyond the stricture was technically successful and well tolerated in 93 (94.9%) of 98 patients. In the failed five patients, it was not possible to negotiate the guide wire due to presence of nearly complete small bowel obstruction. The average length of stricture was 6.15 cm (range, 3 cm to 20 cm) in patients with the colorectal stricture. There were no procedure-related complications. In conclusion, the multifunctional coil catheter seems to be useful in colorectal stent placement. (orig.)

  13. Protecting short-term intravascular ear catheters in healthy rabbits. (United States)

    Sampieri, Francesca; Orchard, Rekha N; Antonopoulos, Aphroditi J; Hamilton, Donald L


    Researchers may place a catheter in the ear vessel of a rabbit for a short period of time in order to collect repeated blood samples without extensive restraint of the animal. Maintaining such a catheter in a healthy rabbit can be challenging, as the animal may scratch at the ear, removing the catheter or forming a large hematoma that might impede blood sampling. The authors developed a technique for protecting the indwelling catheter by cutting a section of moleskin to the same shape as the ear and gluing it to the surface of the ear and the catheter. They applied this technique to collect multiple blood samples during 12-h periods from nine rabbits in a pharmacokinetics study. Catheters remained patent in five rabbits for 12 h, in two rabbits for 8 h, in one rabbit for 6 h and in one rabbit for 4 h. This technique allowed for collection of repeated blood samples and prevented the rabbits from interfering with the catheter while allowing them to move freely during the sampling period.

  14. Percutaneous catheter drainage of intraabdominal abscesses and fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Tae; Kwon, Tae Hee; Yoo, Hyung Sik; Suh, Jung Ho [Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Young Ho [Cheil General Hospital, Seoul (Korea, Republic of)


    Percutaneous catheter drainage has been reported to be an effective method in the management of selected patients with abscess and fluid collection. Its high success rate and relatively low complications make the procedure an alternative to surgery in the individual cases. During past two years percutaneous catheter drainage in 25 patients with intraabdominal abscesses and fluid collection was performed at the Department of Radiology, Yonsei University College of medicine. Here the technique and author's results were summarized. 1. The total 25 patients who had percutaneous catheter drainage are 10 liver abscesses, 3 subphrenic, one subhepatic, 4 renal and perirenal, 2 pelvic, one psoas, one anterior pararenal fluid from acute pancreatitis, one pancreas pseudocyst and 2 malignant tumor necrosis. 2. The modified Seldinger technique used for all cases of abscess and fluid drainage under guidance of ultrasound scan. The used catheters were 10F. Pigtail and 14F. Malecot (Cook c/o) catheters. 3. The abscesses and fluid of 17 patients among 25 were cured by the percutaneous catheter drainage and 4 patients were clinically improved. The catheter drainage was failed in 2 patients and 3 complication were developed. 4. The success rate of this procedure was 91.3%, failure rate was 8.7% and complication rate was 12%.

  15. Manually controlled steerable needle for MRI-guided percutaneous interventions


    Henken, Kirsten R.; Seevinck, Peter R.; Dankelman, Jenny; van den Dobbelsteen, John J.


    This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of th...

  16. Distributed parameter statics of magnetic catheters. (United States)

    Tunay, Ilker


    We discuss how to use special Cosserat rod theory for deriving distributed-parameter static equilibrium equations of magnetic catheters. These medical devices are used for minimally-invasive diagnostic and therapeutic procedures and can be operated remotely or controlled by automated algorithms. The magnetic material can be lumped in rigid segments or distributed in flexible segments. The position vector of the cross-section centroid and quaternion representation of an orthonormal triad are selected as DOF. The strain energy for transversely isotropic, hyperelastic rods is augmented with the mechanical potential energy of the magnetic field and a penalty term to enforce the quaternion unity constraint. Numerical solution is found by 1D finite elements. Material properties of polymer tubes in extension, bending and twist are determined by mechanical and magnetic experiments. Software experiments with commercial FEM software indicate that the computational effort with the proposed method is at least one order of magnitude less than standard 3D FEM.

  17. Steerable Catheter Microcoils for Interventional MRI: Reducing Resistive Heating (United States)

    Bernhardt, Anthony; Wilson, Mark W.; Settecase, Fabio; Evans, Leland; Malba, Vincent; Martin, Alastair J.; Saeed, Maythem; Roberts, Timothy P. L.; Arenson, Ronald L.; Hetts, Steven W.


    PURPOSE To assess resistive heating of microwires used for remote catheter steering in interventional magnetic resonance imaging. To investigate the use of alumina to facilitate heat transfer to saline flowing in the catheter lumen. MATERIALS AND METHODS A microcoil was fabricated using a laser lathe onto polyimide-tipped or alumina-tipped endovascular catheters. In vitro testing was performed in a 1.5 T MR system using a vessel phantom, body RF coil, and steady state pulse sequence. Resistive heating was measured with water flowing over a polyimide tip catheter, or saline flowing through the lumen of an alumina-tip catheter. Preliminary in vivo testing in porcine common carotid arteries was conducted with normal blood flow or after arterial ligation when current was applied to an alumnia-tip catheter for up to 5 minutes. RESULTS After application of up to 1 W of DC power, clinically significant temperature increases were noted with the polyimide-tip catheter: 23°C/W at zero flow, 13°C/W at 0.28 cc/s, and 7.9°C/W at 1 cc/s. Using the alumina-tip catheter, the effluent temperature rise using the lowest flow rate (0.12 cc/s) was 2.3°C/W. In vivo testing demonstrated no thermal injury to vessel walls at normal and zero arterial flow. CONCLUSION Resistive heating in current carrying wire pairs can be dissipated by saline coolant flowing within the lumen of a catheter tip composed of material that facilitates heat transfer. PMID:21075017

  18. In vivo pH monitoring using boron doped diamond microelectrode and silver needles: application to stomach disorder diagnosis. (United States)

    Fierro, Stéphane; Seishima, Ryo; Nagano, Osamu; Saya, Hideyuki; Einaga, Yasuaki


    This study presents the in vivo electrochemical monitoring of pH using boron doped diamond (BDD) microelectrode and silver needles for potential application in medical diagnosis. Accurate calibration curve for pH determination were obtained through in vitro electrochemical measurements. The increase induced in stomach pH by treatment with pantoprazole was used to demonstrate that it is possible to monitor the pH in vivo using the simple and noninvasive system proposed herein. Using the results of the in vivo and in vitro experiments, a quantitative analysis of the increase in stomach pH is also presented. It is proposed that the catheter-free pH monitoring system presented in this study could be potentially employed in any biological environment.

  19. Serrated needle design facilitates precise round window membrane perforation. (United States)

    Stevens, James P; Watanabe, Hirobumi; Kysar, Jeffrey W; Lalwani, Anil K


    The round window membrane (RWM) has become the preferred route, over cochleostomy, for the introduction of cochlear implant electrodes as it minimizes inner ear trauma. However, in the absence of a tool designed for creating precise perforation, current practices lead to tearing of the RWM and significant intracochlear pressure fluctuations. On the basis of RWM mechanical properties, we have designed a multi-serrated needle to create consistent holes without membrane tearing or damaging inner ear structures. Four and eight-serrated needles were designed and produced with wire electrical discharge machining (EDM). The needle's ability to create RWM perforations was tested in deidentified, commercially acquired temporal bones with the assistance of a micromanipulator. Subsequently, specimens were imaged under light and scanning electron microscopy (SEM). The needles created consistent, appropriately sized holes in the membrane with minimal tearing. While a four-serrated crown needle made rectangular/trapezoid perforations, the octagonal crown formed smooth oval holes within the membrane. Though designed for single use, the needle tolerated repeated use without significant damage. The serrated needles formed precise perforations in the RWM while minimizing damage during cochlear implantation. The octagonal needle design created the preferred oval perforation better than the quad needle. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1633-1637, 2016.

  20. Steerable real-time sonographically guided needle biopsy. (United States)

    Buonocore, E; Skipper, G J


    A method for dynamic real-time ultrasonic guidance for percutaneous needle biopsy has been successful in obtaining cytologic and histologic specimens from abdominal masses. The system depends on a real-time ultrasonic transducer that has been rigidly attached to a laterally placed steerable needle holder. Using simple trigonometric functions, a chart has been derived that gives the exact angulation and needle length to produce quick, reliable, guided needle placements. Examples of successful renal, hepatobiliary, and retroperitoneal biopsies are presented. Advantages of this technique include speed, accuracy, low cost, three-dimensional format, and the omission of contrast media and radiation.

  1. Lab in a needle for epidural space identification (United States)

    Carotenuto, B.; Micco, A.; Ricciardi, A.; Amorizzo, E.; Mercieri, M.; Cutolo, A.; Cusano, A.


    This work relies on the development of a sensorized medical needle with an all-optical guidance (Lab in a Needle) system for epidural space identification. The device is based on the judicious integration of a Fiber Bragg grating sensor inside the lumen of an epidural needle to discriminate between different types of tissue and thus providing continuous and real time measurements of the pressure experienced by the needle tip during its advancement. Experiments carried out on an epidural training phantom demonstrate the validity of our approach for the correct and effective identification of the epidural space.

  2. Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

    Energy Technology Data Exchange (ETDEWEB)

    Burton, Kirsteen R. [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada); Guo, Lancia L. Q. [University of Calgary, Department of Radiology (Canada); Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K., E-mail: [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada)


    Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

  3. Hematologic patients' clinical and psychosocial experiences with implanted long-term central venous catheter

    DEFF Research Database (Denmark)

    Møller, Tom; Adamsen, Lis


    A significant decrease in catheter-related infections was demonstrated in our earlier randomized controlled trial of central venous catheter (CVC) care in hematologic patients.......A significant decrease in catheter-related infections was demonstrated in our earlier randomized controlled trial of central venous catheter (CVC) care in hematologic patients....

  4. Ion beam sputter-etched ventricular catheter for hydrocephalus shunt (United States)

    Banks, B. A. (Inventor)


    A cerebrospinal fluid shunt in the form of a ventricular catheter for controlling the condition of hydrocephalus by relieving the excessive cerebrospinal fluid pressure is described. A method for fabrication of the catheter and shunting the cerebral fluid from the cerebral ventricles to other areas of the body is also considered. Shunt flow failure occurs if the ventricle collapse due to improper valve function causing overdrainage. The ventricular catheter comprises a multiplicity of inlet microtubules. Each microtubule has both a large openings at its inlet end and a multiplicity of microscopic openings along its lateral surfaces.

  5. Space Charge Mitigation by Hollow Bunches

    CERN Multimedia

    Oeftiger, AO


    To satisfy the requirements of the HL-LHC (High Luminosity Large Hadron Collider), the LHC injector chain will need to supply a higher brightness, i.e. deliver the same transverse beam emittances \\epsilon_{x,y} while providing a higher intensity N. However, a larger number of particles per bunch enhances space charge effects. One approach to mitigate the impact of space charge is to change the longitudinal phase space distribution: hollow bunches feature a depleted bunch centre and a densely populated periphery. Thus, the spatial line density maximum is depressed which ultimately decreases the tune spread imposed by space charge. Therefore, a higher intensity can be accepted while keeping the same overall space charge tune shift. 3 different methods to create hollow bunches in the PSBooster are simulated.

  6. Hollow antiresonant fibers with reduced attenuation. (United States)

    Belardi, Walter; Knight, Jonathan C


    An improved design for hollow antiresonant fibers (HAFs) is presented. It consists of adding extra antiresonant glass elements within the air cladding region of an antiresonant hollow-core fiber. We use numerical simulations to compare fiber structures with and without the additional cladding elements in the near- and mid-IR regimes. We show that realizable fiber structures can provide greatly improved performance in terms of leakage and bending losses compared to previously reported antiresonant fibers. At mid-IR wavelengths, the adoption of this novel fiber design will lead to HAFs with reduced bending losses. In the near-IR, this design could lead to the fabrication of HAFs with very low attenuation.

  7. Experimental evaluation of a hollow glass fiber. (United States)

    Bornstein, A; Croitoru, N


    Very high interest in making a low-loss fiber for the infrared has been stimulated by important applications in optical communication, surgery, cutting, welding, and heat treatment. The leaky waveguide is one of the most promising types of future fiber in the infrared region where low-loss materials are not available or not suitable for making fibers (i.e., CO2 laser light lambda = 10.6 microm). In this paper a comparative model of a He-Ne laser beam and an oxide glass leaky hollow fiber for a CO2 laser light beam and a chalcogenide glass leaky hollow fiber are studied. Measurements of attenuation, dependence of output power on diameter and angle, and the angular dependence of output angle vs input angle were made. The experimental data were compared with theoretical calculations, and the critical value of the wall thickness for minimum attenuation is given.

  8. Characterizing the elasticity of hollow metal nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ji Changjiang; Park, Harold S [Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235 (United States)


    We have performed atomistic simulations on solid and hollow copper nanowires to quantify the elastic properties of hollow nanowires (nanoboxes). We analyse variations in the modulus, yield stress and strain for <100> and <110> nanoboxes by varying the amount of bulk material that is removed to create the nanoboxes. We find that, while <100> nanoboxes show no improvement in elastic properties as compared to solid <100>nanowires, <110> nanoboxes can show enhanced elastic properties as compared to solid <110> nanowires. The simulations reveal that the elastic properties of the nanoboxes are strongly dependent on the relative strength of the bulk material that has been removed, as well as the total surface area of the nanoboxes, and indicate the potential of ultralight, high-strength nanomaterials such as nanoboxes.

  9. Clinical application of percutaneous treatment of breast abscess via US-guided needle aspiration%超声引导经皮穿刺治疗乳腺脓肿的临床应用

    Institute of Scientific and Technical Information of China (English)

    王福荣; 冷晗; 蔡相军


    目的 评价超声引导下经皮穿刺治疗乳腺脓肿的临床应用价值.方法 在超声引导下,对诊断为乳腺脓肿的病人采用经皮穿刺脓肿抽吸法及脓腔置管引流法进行治疗.结果 45例病人共有54个脓肿,22个最大径≤3 cm的脓肿采用脓肿抽吸法治愈21例,1例改行脓腔置管引流后治愈;32个最大径>3 cm的脓肿实施脓腔置管引流法,治愈30例,切开引流2例.随访41例,复发4例,2例再次行脓腔置管引流治愈,另2例行脓肿切开引流治愈.结论 超声引导下穿刺抽吸治疗不超过3 cm的乳腺脓肿与置管引流治疗超过3 cm的乳腺脓肿均是有效的治疗手段.%Objective To evaluate the clinical value of percutaneous ultrasonography ( US)-guided needle aspiration for breast abscesses. Methods Percutaneous drainage by means of needle aspiration or catheter drainage under ultrasound guidance was performed in the patients who were diagnosed with the breast abscesses. Results Fifty-four abscesses were identified in 45 women. 22 abscesses which the size were 3cm or smaller in maximum diameter were treated with needle aspiration, 21 cases cured and 1 case converted to catheter drainage; 32 abscesses which the size were larger than 3cm in maximum diameter were treated with catheter drainage, 30 cases cured and 2 cases received incision and drainage. Follow-up were performed in 41 cases. Recurrence of breast abscess occurred in 4 patients. 2 cases received catheter drainage again and eventually cured. Conclusion US-guided needle aspiration is the effective method for 3cm or smaller abscesses and US-guided catheter drainage is suited to the abscess larger than 3cm.

  10. Hollow Cone Spray Characterization and Integral Modeling


    Bollweg, Peter


    The thesis presents a computationally efficient spray model for hollow cone sprays suitable for engine system simulation of direct injecting gasoline internal combustion engines. The model describes the transient evolution of the spray as a two-phase jet. Spatial gradients are resolved along the main injection direction. Momentum exchange, droplet heat-up, and fuel evaporation are accounted for. Diffusive transport of momentum, energy, and fuel species mass between the dense spray zone an...

  11. Hollow Cathode With Multiple Radial Orifices (United States)

    Brophy, John R.


    Improved hollow cathode serving as source of electrons has multiple radial orifices instead of single axial orifice. Distributes ion current more smoothly, over larger area. Prototype of high-current cathodes for ion engines in spacecraft. On Earth, cathodes used in large-diameter ion sources for industrial processing of materials. Radial orientation of orifices in new design causes current to be dispersed radially in vicinity of cathode. Advantageous where desireable to produce plasma more nearly uniform over wider region around cathode.

  12. Hollow Sucker Rod Applied in Production Engineering

    Institute of Scientific and Technical Information of China (English)

    Wang Tongbin; Liu Liandong; Hu Daoming; Jia Yanshan


    @@ Working Principle A positive cycle system or a working channel can be formed by means of hollow sucker rod and its mating parts in the oil tube ofa well, through which heat carriers (such as hot water,hot oil and steam), chemicals and heating cable can be pumped or put into the well so as to lower the viscosity of crude, dissolve the paraffin building-up and open the conduit, thus leading to the smooth oil flow out of well.

  13. The Hollow Cathode Phase of Pseudospark Operation (United States)


    THE HOLLOW CATHODE PHASE OF PSEUDOSPARK OPERATION L. Pitchford and J. P. Boeuf University Paul Sabatier, France V. Puech University De Paris-Sud...ORGANIZATION NAME(S) AND ADDRESS(ES) University Paul Sabatier, France 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME...Appl. Phys. 53, 1699 (1988). [9] A. Anders, S. Anders, and M. Gundersen, submitted to Phys. Rev. Lett. [10] J. P. Boeuf and L. Pitchford , IEEE

  14. Chalcogenide glass hollow core microstructured optical fibers (United States)

    Shiryaev, Vladimir S.


    The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs) are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  15. Formation of hollow atoms above a surface (United States)

    Briand, Jean Pierre; Phaneuf, Ronald; Terracol, Stephane; Xie, Zuqi


    Slow highly stripped ions approaching or penetrating surfaces are known to capture electrons into outer shells of the ions, leaving the innermost shells empty, and forming hollow atoms. Electron capture occurs above and below the surfaces. The existence of hollow atoms below surfaces e.g. Ar atoms whose K and L shells are empty, with all electrons lying in the M and N shells, was demonstrated in 1990 [1]. At nm above surfaces, the excited ions may not have enough time to decay before hitting the surfaces, and the formation of hollow atoms above surfaces has even been questioned [2]. To observe it, one must increase the time above the surface by decelerating the ions. We have for the first time decelerated O^7+ ions to energies as low as 1 eV/q, below the minimum energy gained by the ions due to the acceleration by their image charge. As expected, no ion backscattering (trampoline effect) above dielectric (Ge) was observed and at the lowest ion kinetic energies, most of the observed x-rays were found to be emitted by the ions after surface contact. [4pt] [1] J. P. Briand et al., Phys.Rev.Lett. 65(1990)159.[0pt] [2] J.P. Briand, AIP Conference Proceedings 215 (1990) 513.

  16. The impact of sodium citrate on dialysis catheter function and frequency of catheter-related bacteriemia and haemorrhage

    Directory of Open Access Journals (Sweden)

    Maciej Szymczak


    Full Text Available Vascular access is one of the most important problems of hemodialysis therapy. It is known that an arteriovenous fi sutla provides the best vascular access, but its creation is not always possible. Other solutions, such as the insertion of a central venous catheter, are then required. Adequate protection of such catheters by interdialytic fi ll with locking solution affects the frequency of hemodialysis-related complications. The most widespread catheter locking solution is heparin. Sodium citrate is being used more frequent recently. Available data indicate that hemorrhage is 11.9 times more frequent if the catheter locking solution is 5000 IU/ml heparin than if 4�0sodium citrate or 1000 IU/ml heparin is used. Other data indicate that the frequency of infection is statistically decreased when 30�0sodium citrate is used to fi ll the catheter instead of 5000 IU/ml heparin. Analogous data on 46.7�0sodium citrate are not consistent. It seems that the use of 4�0sodium citrate instead of 5000 IU/ml heparin does not decrease the frequency of infections. Numerous studies indicate that sodium citrate at various concentrations exerts a positive infl lence on catheter function. However, not all data are in accord. The spill of sodium citrate from the catheter to the systemic circulation is connected with a risk of adverse events. It may be dangerous if the citrate concentration is 46.7�20However, adequate fi lling of the catheter should prezent such events. Available data indicate that fi lling of the catheter with a solution of citrate of a concentration of no more than 30�0should be safe. Data on 46.7�0citrate are not conclusive, so precautions should be taken.

  17. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator (United States)

    He, Siyu; Gomez-Tames, Jose; Yu, Wenwei


    As one of neurological tests, needle electromygraphy exam (NEE) plays an important role to evaluate the conditions of nerves and muscles. Neurology interns and novice medical staff need repetitive training to improve their skills in performing the exam. However, no training systems are able to reproduce multiple pathological conditions to simulate real needle electromyogram exam. For the development of a robotic simulator, three components need to be realized: physical modeling of upper limb morphological features, position-dependent electromyogram generation, and needle localization; the latter is the focus of this study. Our idea is to couple two types of sensing mechanism in order to acquire the needle-tip position with high accuracy. One is to segment the needle from camera images and calculate its insertion point on the skin surface by a top-hat transform algorithm. The other is voltage-based depth measurement, in which a conductive tissue-like phantom was used to realize both needle-tip localization and physical sense of needle insertion. For that, a pair of electrodes was designed to generate a near-linear voltage distribution along the depth direction of the tissue-like phantom. The accuracy of the needle-tip position was investigated by the electric field potential and camera hybridization. The results showed that the needle tip could be detected with an accuracy of 1.05±0.57 mm. PMID:27382339

  18. Silica hollow spheres with nano-macroholes like diatomaceous earth. (United States)

    Fujiwara, Masahiro; Shiokawa, Kumi; Sakakura, Ikuko; Nakahara, Yoshiko


    Artificial synthesis of hollow cell walls of diatoms is an ultimate target of nanomaterial science. The addition of some water-soluble polymers such as sodium polymethacrylate to a solution of water/oil/water emulsion system, which is an essential step of the simple synthetic procedure of silica hollow spheres (microcapsules), led to the formation of silica hollow spheres with nano-macroholes (>100 nm) in their shell walls, the morphologies of which are analogous to those of diatom earth.

  19. Generation of a Dark Hollow Beam inside a Cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; LU Xuan-Hui; CHEN Xu-Min; HE Sai-Ling


    @@ A new method is introduced to generate a hollow beam inside a cavity. Using a matrix eigenvalue method, the laser resonator with optical diffraction elements is theoretically analysed and simulated. The hollow beam can be obtained theoretically by controlling the parameters of the diffraction functions. After designed the diffraction components in the cavity, a hollow beam of good quality is realized experimentally using a YAG solid state laser.

  20. Preparation of Nanocrystalline MoS2 Hollow Spheres

    Institute of Scientific and Technical Information of China (English)


    Nanocrystalline MoS2 with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the sample is consists of hollow spheres 400~600 nm in diameter, and there is much whisker on the surface of MoS2 hollow sphere.

  1. Review of Synthetic Methods to Form Hollow Polymer Nanocapsules

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Madeline T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Syntactic foams have grown in interest due to the widened range of applications because of their mechanical strength and high damage tolerance. In the past, hollow glass or ceramic particles were used to create the pores. This paper reviews literature focused on the controlled synthesis of hollow polymer spheres with diameters ranging from 100 –200 nm. By using hollow polymer spheres, syntactic foams could reach ultra-low densities.

  2. Optical properties of hollow calcium aluminate glass waveguides. (United States)

    Abel, T; Harrington, J A; Foy, P R


    Calcium aluminate glass has a refractive index less than 1 at 10.6 µ, and therefore it is a good candidate for a hollow fiber for the transmission of CO(2) laser energy. We have drawn hollow calcium aluminate glass fibers with inner diameters ranging from 380 to 500 µ. The loss for our 500-µm inner-diameter hollow glass fibers measured at 10.6 µm is 8.6 dB/m.

  3. Interference Assembly and Fretting Wear Analysis of Hollow Shaft


    Chuanjun Han; Jie Zhang


    Fretting damage phenomenon often appears in the interference fit assembly. The finite element model of hollow shaft and shaft sleeve was established, and the equivalent stress and contact stress were computed after interference assembly. The assembly body of hollow shaft and shaft sleeve was in whirling bending load, and the contact status (sticking, sliding, and opening) and the distribution of stress along one typical contact line were computed under different loads, interferences, hollow d...

  4. Space Charge MitigationWith Longitudinally Hollow Bunches

    CERN Document Server

    Oeftiger, Adrian; Rumolo, Giovanni; CERN. Geneva. ATS Department


    Suitably, hollow longitudinal phase space distributions have a flat profile and hence reduce the impact of transverse space charge. Dipolar parametric excitation with the phase loop feedback systems provides such hollow distributions under reproducible conditions. We present a procedure to create hollow bunches during the acceleration ramp of CERN’s PS Booster machine with minimal changes to the operational cycle. The improvements during the injection plateau of the downstream Proton Synchrotron are assessed in comparison to standard parabolic bunches.

  5. Effect of Arm Positioning on Entrapment of Infraclavicular Nerve Block Catheter (United States)

    Reddy, Rahul; Kendall, Mark C.; Nader, Antoun; Weeks, Jessica J.


    Continuous brachial plexus nerve block catheters are commonly inserted for postoperative analgesia after upper extremity surgery. Modifications of the insertion technique have been described to improve the safety of placing an infraclavicular brachial plexus catheter. Rarely, these catheters may become damaged or entrapped, complicating their removal. We describe a case of infraclavicular brachial plexus catheter entrapment related to differences in arm positioning during catheter placement and removal. Written authorization to obtain, use, and disclose information and images was obtained from the patient.

  6. Radiographic signs of non-venous placement of intended central venous catheters in children

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Erin C. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Taylor, George A. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Harvard Medical School, Department of Radiology, Boston, MA (United States)


    Central venous catheters (CVCs) are commonly used in children, and inadvertent arterial or extravascular cannulation is rare but has potentially serious complications. To identify the radiographic signs of arterial placement of CVCs. We retrospectively reviewed seven cases of arterially malpositioned CVCs on chest radiograph. These cases were identified through departmental quality-assurance mechanisms and external consultation. Comparison of arterial cases was made with 127 age-matched chest radiographs with CVCs in normal, expected venous location. On each anteroposterior (AP) radiograph we measured the distance of the catheter tip from the right lateral border of the thoracic spine, and the angle of the vertical portion of the catheter relative to the midline. On each lateral radiograph we measured the angle of the vertical portion of each catheter relative to the anterior border of the thoracic spine. When bilateral subclavian catheters were present, the catheter tips were described as crossed, overlapping or uncrossed. On AP radiographs, arterially placed CVCs were more curved to the left, with catheter tip positions located farther to the left of midline than normal venous CVCs. When bilateral, properly placed venous catheters were present, all catheters crossed at the level of the superior vena cava (SVC). When one of the bilateral catheters was in arterial position, neither of the catheters crossed or the inter-catheter crossover distance was exaggerated. On lateral radiographs, there was a marked anterior angulation of the vertical portion of the catheter (mean angle 37 ± 15 standard deviation [SD] in arterial catheters versus 5.9 ± 8.3 SD in normally placed venous catheters). Useful radiographic signs suggestive of unintentional arterial misplacement of vascular catheters include leftward curvature of the vertical portion of the catheter, left-side catheter tip position, lack of catheter crossover on the frontal radiograph, as well as exaggerated

  7. Complex Hollow Nanostructures: Synthesis and Energy-Related Applications. (United States)

    Yu, Le; Hu, Han; Wu, Hao Bin; Lou, Xiong Wen David


    Hollow nanostructures offer promising potential for advanced energy storage and conversion applications. In the past decade, considerable research efforts have been devoted to the design and synthesis of hollow nanostructures with high complexity by manipulating their geometric morphology, chemical composition, and building block and interior architecture to boost their electrochemical performance, fulfilling the increasing global demand for renewable and sustainable energy sources. In this Review, we present a comprehensive overview of the synthesis and energy-related applications of complex hollow nanostructures. After a brief classification, the design and synthesis of complex hollow nanostructures are described in detail, which include hierarchical hollow spheres, hierarchical tubular structures, hollow polyhedra, and multi-shelled hollow structures, as well as their hybrids with nanocarbon materials. Thereafter, we discuss their niche applications as electrode materials for lithium-ion batteries and hybrid supercapacitors, sulfur hosts for lithium-sulfur batteries, and electrocatalysts for oxygen- and hydrogen-involving energy conversion reactions. The potential superiorities of complex hollow nanostructures for these applications are particularly highlighted. Finally, we conclude this Review with urgent challenges and further research directions of complex hollow nanostructures for energy-related applications.

  8. Manufacturing hollow obturator with resilient denture liner on post hemimaxillectomy

    Directory of Open Access Journals (Sweden)

    Michael Josef Kridanto Kamadjaja


    Full Text Available A resilient denture liner is placed in the part of the hollow obturator base that contacts to post hemimaxillectomy mucosa. Replacing the resilient denture liner can makes the hollow obturator has an intimate contact with the mucosa, so it can prevents the mouth liquid enter to the cavum nasi and sinus, also eliminates painful because of using the hollow obturator. Resilient denture liner is a soft and resilient material that applied to the fitting surface of a denture in order to allow a more distribution of load. A case was reported about using the hollow obturator with resilient denture liner on post hemimaxillectomy to overcome these problems.

  9. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes) are predo......Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...

  10. Dialysis Catheters and Their Common Complications: An Update

    Directory of Open Access Journals (Sweden)

    Satyaki Banerjee


    Full Text Available Tunneled dialysis catheters (TDCs are associated with the highest rate of complications, morbidity, and mortality when compared to arteriovenous fistulas or grafts, and this relates to higher costs in their management. Over time, catheters are prone to higher rates of infection, thrombosis, and central venous stenosis, and, thereby, catheter dysfunction. Lower blood flow rates are a consequence of the dysfuncion. Despite efforts to reduce incident and prevalent rates of catheter use for dialysis by the National Kidney Foundation and Fistula First Initiative, they remain a common modality of hemodialysis. The management of common TDC-related complications is discussed, in addition to ways to reduce and prevent morbidity associated with their use.

  11. Review of advanced catheter technologies in radiation oncology brachytherapy procedures. (United States)

    Zhou, Jun; Zamdborg, Leonid; Sebastian, Evelyn


    The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented.

  12. Thermal and hydrodynamic modelling of active catheters for interventional radiology. (United States)

    Marchandise, Emilie; Flaud, Patrice; Royon, Laurent; Blanc, Raphaël; Szewczyk, Jérome


    Interventional radiologists desire to improve their operating tools such as catheters. Active catheters in which the tip is moved using shape memory alloy actuators activated using the Joule effect present a promising approach for easier navigation in the small vessels. However, the increase in temperature caused by this Joule effect must be controlled in order to prevent damage to blood cells and tissues. This paper is devoted to the simulation and experimental validation of a fluid-thermal model of an active catheter prototype. Comparisons between computer-predicted and experimentally measured temperatures are presented for both experiments in air and water at 37°C. Good agreement between the computational and experimental results is found, demonstrating the validity of the developed computer model. These comparisons enable us to highlight some important issues in the modelling process and to determine the optimal current for the activation of the catheter.

  13. Continuous quality improvement: improving hemodialysis catheter patency using urokinase. (United States)

    Northsea, C


    Opportunities for improvements in patient outcomes through applied continuous quality improvement (CQI) programs are endless and exciting. Improving vascular access outcomes has been a long-standing clinical problem for hemodialysis patients and the nephrology team. During the past few years there has been a dramatic increase in the use of dialysis catheters as permanent accesses for hemodialysis patients. All hemodialysis with dialysis catheters are at risk for catheter occlusion. An innovative, 2-year CQI program was developed, implemented, and designed to improve dialysis catheter patency rates with the use of urokinase. The CQI program resulted in a number of clinical outcomes that were beneficial to the patients and dialysis staff, and were cost-effective to the program.

  14. Urinary catheter related nosocomial infections in paediatric intensive care unit.

    Directory of Open Access Journals (Sweden)

    Tullu M


    Full Text Available The present prospective study was carried out in the Paediatric Intensive Care Unit (PICU of a tertiary care teaching hospital in Mumbai. The objective was to determine the incidence, risk factors, mortality and organisms responsible for urinary catheter related infections (UCRI. Colonization and/or bacteriuria was labelled as urinary catheter related infection (UCRI. Forty-four patients with 51 urinary catheters were studied. Incidence of UCRI was 47.06%. Age, female sex and immunocompromised status did not increase the risk of UCRI. Duration of catheter in-situ and duration of stay in the PICU were associated with higher risk of UCRI. The mortality was not increased by UCRI. Commonest organism isolated in UCRI was E. coli, which had maximum susceptibility to nitrofurantoin and amikacin.

  15. Advancements in Catheter-Directed Ultrasound-Accelerated Thrombolysis

    NARCIS (Netherlands)

    Doomernik, Denise E.; Schrijver, A. Marjolein; Zeebregts, Clark J.; de Vries, Jean-Paul P. M.; Reijnen, Michel M. P. J.


    Purpose: To review all available literature on catheter-directed ultrasound-accelerated thrombolysis for peripheral artery occlusions, stroke, deep venous thrombosis, and pulmonary embolism. Methods: A systematic literature search was performed, using MEDLINE, EMBASE and Cochrane databases. A total

  16. Advancements in catheter-directed ultrasound-accelerated thrombolysis.

    NARCIS (Netherlands)

    Doomernik, D.E.; Schrijver, A.M.; Zeebregts, C.J.A.; Vries, J.P. de; Reijnen, M.M.P.J.


    PURPOSE: To review all available literature on catheter-directed ultrasound-accelerated thrombolysis for peripheral artery occlusions, stroke, deep venous thrombosis, and pulmonary embolism. METHODS: A systematic literature search was performed, using MEDLINE, EMBASE and Cochrane databases. A total

  17. Three Dimensional Modeling of an MRI Actuated Steerable Catheter System. (United States)

    Liu, Taoming; Cavuşoğlu, M Cenk


    This paper presents the three dimensional kinematic modeling of a novel steerable robotic ablation catheter system. The catheter, embedded with a set of current-carrying micro-coils, is actuated by the magnetic forces generated by the magnetic field of the MRI scanner. This paper develops a 3D model of the MRI actuated steerable catheter system by using finite differences approach. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using beam theory. By using the deflection displacements and torsion angles, the kinematic modeling of the catheter system is derived. The proposed models are evaluated by comparing the simulation results of the proposed model with the experimental results of a proof-of-concept prototype.

  18. Pericardial tamponade and death from Hickman catheter perforation. (United States)

    Murray, B H; Cohle, S D; Davison, P


    In February 1995, a 56-year-old female was taken to the operating room for routine placement of a Hickman catheter. Her internist planned palliative chemotherapy for metastatic breast cancer. Using the Seldinger technique, the right subclavian vein was entered and a Hickman catheter was placed. Shortly after extubation and arrival in the postoperative recovery unit, the patient had respiratory and cardiac arrest. Resuscitative efforts, including chest tube placement and pericardiocentesis, were unsuccessful. Autopsy findings included perforation of the superior vena cava, with extension of the catheter in the pericardial sac and associated effusion. Despite the low reported incidence of perforation during placement of central venous catheters, we recommend confirmation of placement by fluoroscopy and instillation of radiopaque dye because of the high mortality associated with this complication.

  19. Automatic rupture of unused intraport catheter. Case report. (United States)

    Pappas, Paris; Dalianis, Nikolaos; Filippou, Dimitrios K; Condiis, Nicolas; Rizos, Spiros; Skandalakis, Panagiotis


    Totally Implantable Central Venous Access Devices (Intraports) are commonly used in cancer patients to administer chemotherapy or parenteral nutrition. These devices are placed by Seldinger technique. We report an unusual case of intraport catheter rupture before the use of the device. The ruptured part of the catheter migrated into the left pulmonary vein via right ventricle. The ruptured part was removed by means of interventional radiology before causing any problems to the patient. All the reported ruptures of port catheters refer to port devices that had been used to administer chemotherapy, fluids, or parenteral nutrition. The unique feature of this case is that the catheter had not been used at all. It is of great interest also the removal of the broken part from the pulmonary vein.

  20. Anatomical Consideration in Catheter Ablation of Idiopathic Ventricular Arrhythmias. (United States)

    Yamada, Takumi; Kay, G Neal


    Idiopathic ventricular arrhythmias (VAs) are ventricular tachycardias (VTs) or premature ventricular contractions (PVCs) with a mechanism that is not related to myocardial scar. The sites of successful catheter ablation of idiopathic VA origins have been progressively elucidated and include both the endocardium and, less commonly, the epicardium. Idiopathic VAs usually originate from specific anatomical structures such as the ventricular outflow tracts, aortic root, atrioventricular (AV) annuli, papillary muscles, Purkinje network and so on, and exhibit characteristic electrocardiograms based on their anatomical background. Catheter ablation of idiopathic VAs is usually safe and highly successful, but can sometimes be challenging because of the anatomical obstacles such as the coronary arteries, epicardial fat pads, intramural and epicardial origins, AV conduction system and so on. Therefore, understanding the relevant anatomy is important to achieve a safe and successful catheter ablation of idiopathic VAs. This review describes the anatomical consideration in the catheter ablation of idiopathic VAs.

  1. Review of advanced catheter technologies in radiation oncology brachytherapy procedures


    Zhou J.; Zamdborg L; Sebastian E


    Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy ...

  2. Magnetic and robotic navigation for catheter ablation: "joystick ablation". (United States)

    Ernst, Sabine


    Catheter ablation has become the treatment of choice to cure various arrhythmias in the last decades. The newest advancement of this general concept is made on the navigation ability using remote-controlled ablation catheters. This review summarizes the concept of the two currently available systems, followed by a critical review of the published clinical reports for each system, respectively. Despite the limited amount of data, an attempt to compare the two systems is made.

  3. Clinical Practice Guidelines for Vascular Catheter Infections Treatment.

    Directory of Open Access Journals (Sweden)

    Belkys Rodríguez Llerena


    Full Text Available Clinical Practice Guidelines for Vascular Catheter Infections Treatment. It has been defined as the presence of local or systemic signs without other obvious infection site, plus the microbiologic evidence involving the catheter. This document includes a review and update of concepts, main clinical aspects, and treatment and stresses the importance of prophylactic treatment. It includes assessment guidelines focused on the most important aspects to be accomplished.

  4. Needle Steering in 3-D Via Rapid Replanning (United States)

    Patil, Sachin; Burgner, Jessica; Webster, Robert J.; Alterovitz, Ron


    Steerable needles have the potential to improve the effectiveness of needle-based clinical procedures such as biopsy and drug delivery by improving targeting accuracy and reaching previously inaccessible targets that are behind sensitive or impenetrable anatomical regions. We present a new needle steering system capable of automatically reaching targets in 3-D environments while avoiding obstacles and compensating for real-world uncertainties. Given a specification of anatomical obstacles and a clinical target (e.g., from preoperative medical images), our system plans and controls needle motion in a closed-loop fashion under sensory feedback to optimize a clinical metric. We unify planning and control using a new fast algorithm that continuously replans the needle motion. Our rapid replanning approach is enabled by an efficient sampling-based rapidly exploring random tree (RRT) planner that achieves orders-of-magnitude reduction in computation time compared with prior 3-D approaches by incorporating variable curvature kinematics and a novel distance metric for planning. Our system uses an electromagnetic tracking system to sense the state of the needle tip during the procedure. We experimentally evaluate our needle steering system using tissue phantoms and animal tissue ex vivo. We demonstrate that our rapid replanning strategy successfully guides the needle around obstacles to desired 3-D targets with an average error of less than 3 mm. PMID:25435829

  5. Manually controlled steerable needle for MRI-guided percutaneous interventions

    NARCIS (Netherlands)

    Henken, Kirsten R; Seevinck, Peter R; Dankelman, Jenny; van den Dobbelsteen, John J


    This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting s

  6. Path planning for steerable needles using duty-cycled spinning

    Directory of Open Access Journals (Sweden)

    Borges G.A.


    Full Text Available This paper presents an adaptive approach for 2D path planning of steerable needles. It combines dutycycled rotation of the needle with the classic RapidlyExploring Random Tree (RRT algorithm and it is used intraoperatively to compensate for system uncertainties and perturbations. Simulation results demonstrate the performance of the proposed motion planner on a workspace based in ultrasound images.

  7. Observations on rotating needle insertions using a brachytherapy robot

    Energy Technology Data Exchange (ETDEWEB)

    Meltsner, M A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Ferrier, N J [Department of Mechanical Engineering, University of Wisconsin, Madison, WI 53706 (United States); Thomadsen, B R [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States)


    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.

  8. Synthesis of nano-crystalline multifibrous zirconia needle

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Mridula; Bandyopadhyay, Siddhartha, E-mail:


    Graphical abstract: - Highlights: • Zirconia needles have been successfully prepared by simple inorganic sol–gel route. • The shape of the needles was retained after firing with aspect ratio > 400. • Needles are composed of multiple fibres. • Fibres are composed of nano crystals. - Abstract: Zirconia needles have been successfully synthesized using a simple inorganic sol–gel process without using any template. The method employs mixture of zirconium oxychloride octahydrate and sulphuric acid in aqueous medium. This process requires heat treatment at 40 °C for 2 h in an oven for nucleus formation. Complete formation of needle occurs after 17 days. The green needle retained its original shape after calcination at 1200 °C. Fired needles were of 1–2 cm in length and 5–50 μm in diameter and possess monoclinic phase. Needles are composed of multiple fibres. Depending on the heat treatment temperature, crystallite size varies in the range of 8 to around 300 nm.

  9. Needle Steering in 3-D Via Rapid Replanning. (United States)

    Patil, Sachin; Burgner, Jessica; Webster, Robert J; Alterovitz, Ron


    Steerable needles have the potential to improve the effectiveness of needle-based clinical procedures such as biopsy and drug delivery by improving targeting accuracy and reaching previously inaccessible targets that are behind sensitive or impenetrable anatomical regions. We present a new needle steering system capable of automatically reaching targets in 3-D environments while avoiding obstacles and compensating for real-world uncertainties. Given a specification of anatomical obstacles and a clinical target (e.g., from preoperative medical images), our system plans and controls needle motion in a closed-loop fashion under sensory feedback to optimize a clinical metric. We unify planning and control using a new fast algorithm that continuously replans the needle motion. Our rapid replanning approach is enabled by an efficient sampling-based rapidly exploring random tree (RRT) planner that achieves orders-of-magnitude reduction in computation time compared with prior 3-D approaches by incorporating variable curvature kinematics and a novel distance metric for planning. Our system uses an electromagnetic tracking system to sense the state of the needle tip during the procedure. We experimentally evaluate our needle steering system using tissue phantoms and animal tissue ex vivo. We demonstrate that our rapid replanning strategy successfully guides the needle around obstacles to desired 3-D targets with an average error of less than 3 mm.

  10. Review of advanced catheter technologies in radiation oncology brachytherapy procedures

    Directory of Open Access Journals (Sweden)

    Zhou J


    Full Text Available Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented. Keywords: catheter technologies, catheter reconstruction, electromagnetic tracking, hypofractionated high dose rate treatment, accelerated partial breast irradiation

  11. [Anesthetic consideration in patients undergoing catheter ablation for atrial fibrillation]. (United States)

    Oda, Toshiyuki; Takahama, Yutaka


    This chapter describes anesthetic consideration in patients undergoing catheter ablation for atrial fibrillation (AF) based on electrophysiologic or pharmacological aspects. In the 2011 guidelines of the Japanese Circulation Society for non-pharmacotherapy of cardiac arrhythmias, catheter ablation is recommended as Class I therapeutic modality for the patients with drug-refractory paroxysmal AF. Catheter ablation of AF is an invasive and long-lasting procedure necessitating sedation during treatment. However, in the most of the patients, sedation or anesthesia is possibly performed by cardiologists using propofol, midazolam or dexmedetomidine. Deep sedation accompanies a high risk of ventilatory or circulatory derangement. Furthermore, life-threatening complications, such as cerebral infarction or cardiac tamponade, can occur during ablation. Patients with AF are increasing in number as a trend in the aging society, resulting in an increase in catheter ablation in high risk patients. To accomplish safe anesthetic management of the patients for catheter ablations, anesthesiologists are required to have fundamental knowledge and skill in the performance of the catheter ablation.

  12. Misplaced central venous catheters: applied anatomy and practical management. (United States)

    Gibson, F; Bodenham, A


    Large numbers of central venous catheters (CVCs) are placed each year and misplacement occurs frequently. This review outlines the normal and abnormal anatomy of the central veins in relation to the placement of CVCs. An understanding of normal and variant anatomy enables identification of congenital and acquired abnormalities. Embryological variations such as a persistent left-sided superior vena cava are often diagnosed incidentally only after placement of a CVC, which is seen to take an abnormal course on X-ray. Acquired abnormalities such as stenosis or thrombosis of the central veins can be problematic and can present as a failure to pass a guidewire or catheter or complications after such attempts. Catheters can also be misplaced outside veins in a patient with otherwise normal anatomy with potentially disastrous consequences. We discuss the possible management options for these patients including the various imaging techniques used to verify correct or incorrect catheter placement and the limitations of each. If the course of a misplaced catheter can be correctly identified as not lying within a vulnerable structure then it can be safely removed. If the misplaced catheter is lying within or traversing large and incompressible arteries or veins, it should not be removed before consideration of what is likely to happen when it is removed. Advice and further imaging should be sought, typically in conjunction with interventional radiology or vascular surgery. With regard to misplaced CVCs, in the short term, a useful aide memoir is: 'if in doubt, don't take it out'.

  13. Placement peripherally inserted central catheters (PICC): the upper arm approach

    Energy Technology Data Exchange (ETDEWEB)

    Choo, In Wook; Choo, Sung Wook; Choi, Dong Il; Yoon, Jung Hwan; Hwang, Jae Woong; Lim, Jae Hoon [Samsung Medical Center, Seoul (Korea, Republic of); Andrews, James C. [Mayo Clinic, Lansing (United States); Williams, David M.; Cho, Kyung J. [University of Michigan Hospital, Lansing (United States)


    To evaluate a recently developed technique to place a medium-duration (weeks to months) central venous access. Within three-year period, 635 patients were referred to interventional radiology suite for placement of peripherally inserted central catheter (PICC). Contrast medium was injected into the peripheral intravenous line and a puncture was made into the opacified vein near the junction of the middle and upper thirds of the upper arm, either the brachial or basilic vein under fluoroscopic guidance. A 5.5-French peel-away sheath was inserted into the vein and a 5-French silicone catheter was introduced with its distal tip to the junction of the right atrium and superior vena cava. Catheter placement was successful in all patients unless there was a central venous obstruction. Catheters were maintained from 2 days to 5 months with a mean of 3 weeks. Complications included infection requiring removal of the PICC in 16 patients (2.5%), acute thrombosis of the subclavian vein in 3 (0.5%). Occluded catheters in 4 patients were easily cleared with urokinase in place. The PICC system is an excellent option for medium-duration central venous access. Patients were able to carry on normal activities with the catheters in place.

  14. Technical considerations in the use of external condom catheter systems. (United States)

    deHoll, J D; Williams, L A; Steers, W D; Rodeheaver, G T; Clark, M M; Edlich, R F


    Since the advent of rehabilitation engineering new advances have been made that have revolutionized condom catheter drainage systems (CCDS). An innovative CCDS has been designed that ensures unobstructed urine flow. Its condom catheter has several unique design features. It has a double row of convolutions near the catheter tip that prevent kinking and twisting so that the pathway remains open. The condom catheter features a unique inner flap that fits snugly on the glans to prevent backflow of urine on the shaft. This condom catheter is connected to a vented leg bag that eliminates the development of a partial vacuum in the connecting tube. This vacuum can create siphoning, which in turn interferes with urine flow into the leg bag. In addition, a new rechargeable battery-operated clipper has been developed that makes nick-free hair removal from the genitals exceptionally easy. This atraumatic hair removal eliminates the pubic hair that becomes trapped under the condom catheter. The clinical impact of these new advances in CCDS requires further investigation.

  15. Design of an Optically Controlled MR-Compatible Active Needle (United States)

    Ryu, Seok Chang; Quek, Zhan Fan; Koh, Je-Sung; Renaud, Pierre; Black, Richard J.; Moslehi, Behzad; Daniel, Bruce L.; Cho, Kyu-Jin; Cutkosky, Mark R.


    An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy. PMID:26512231

  16. Removal of an embedded crochet needle in the mouth. (United States)

    Klovenski, Victoria; Juergens, Andrew; Lappo, Kyla; Marshall, Kyle


    A 3-year-old child presented to the emergency department with a crochet needle lodged in her posterior oral cavity. To localize the needle and significant surrounding anatomic structures, bedside transcavitary ultrasound was employed. After careful localization, the needle was removed using a modified needle cover technique. A review of barbed foreign object removal techniques, including advance-and-cut, retrograde, string-yank, and needle cover techniques, is presented. Important considerations while planning any procedure include risk, benefit, availability of staff, and availability of equipment. Proper anesthesia is paramount to the success of these procedures, and sedation in pediatric patients may prove necessary. Postprocedure wound care and follow-up must also be arranged. This case demonstrates the importance of adaptation of well-documented techniques to remain flexible for any situation that may present to the emergency department.

  17. A novel accurate minioptical tracking system for percutaneous needle placement. (United States)

    von Jako, Christopher R; Zuk, Yuval; Zur, Oded; Gilboa, Pini


    The novel optical tracking system employs a miniature video camera, mounted on the hub of an interventional needle, to determine the location and orientation of the needle relative to a skin-attached sticker with color reference markers. A computed tomography (CT) scan is used to register the same reference markers to the anatomy in the CT images, and thus, register the needle to the anatomy and to a user-selected target. A computer displays a simulation of the interventional needle on the CT images, providing guidance information to assist a user in directing the needle to the target. Bench testing was performed on a custom phantom to determine the accuracy of this minioptical tracking system. The resulting accuracy data demonstrate a good correlation with phantom coordinates and the CT images.

  18. Effect of physical disturbance on the structure of needle coke (United States)

    Zhao, Shi-Gui; Wang, Bao-Cheng; Sun, Quan


    Through different preparation technology, this paper reports that the needle coke is prepared with coal-tar pitch under the effect of magnetic field and ultrasonic cavitation. It studies the effect of physical disturbance on the structure of needle coke. The structure of needle coke is characterized by scanning electron microscope and x-ray diffractometer, and the influence mechanism is analysed. Results showed that the structure and property of needle coke could be effectively improved by magnetic field and ultrasonic cavitations, such as degree of order, degree of graphitization and crystallization. Comparatively speaking, the effect of magnetic field was greater. The graphitization degree of needle coke prepared under the effect of magnetic field is up to 45.35%.

  19. Potential In Vivo UVC Disinfection of Catheter Lumens: Estimation of the Doses Received by the Blood Flow Outside the Catheter Tip Hole

    DEFF Research Database (Denmark)

    Bak, Jimmy; Jørgensen, Thomas Martini; Helfmann, Jurgen;


    We have demonstrated that it is possible to launch UVC LED light into bacterial contaminated polymer tubes/catheters and disinfect the intraluminal space of these tubes. This can be achieved by UVC treatment of the catheters on a regular basis. Catheters are in the distal end equipped with an exi...

  20. Usefulness of CT-Guided Percutaneous Catheter Drainage Using a Modified Version of the Seldinger Technique for the Treatment of Intra-abdominal Small Abscess and Poorly Depicted Fluid Collection on Sonogram

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chi Sung [Boramae Hospital, Seoul (Korea, Republic of)


    To evaluate the usefulness of CT-guided percutaneous catheter drainage (PCD) using a modified version of the Seldinger technique for deep-seated, small abscesses and poorly depicted fluid collection on abdominal sonogram. Fifty-nine cases of CT-guided PCD were performed on 56 patients. Four techniques were applied to secure safe access routes, which include scan postural change, angulation of the gantry, traversal of organs, and using a dissecting needle which can push the intervening bowel. Three landmarks (depth of the front and back wall of the fluid collection and the end point of catheter advancement over the guide wire) were indicated on the drainage catheter for extracorporeal direct observation of moving distance and location of the catheter during the insertion process. The technical success rate, clinical outcome, complications, and instrumental impairments were reviewed. The technical success rate was 100% (59/59), and no grave complications occurred. Four cases (7%) of crooked guide wire insertion were noted. The clinical outcome revealed a 95% (56/59) successful treatment rate and a 5% (3/59) failed treatment rate, which was caused by undissolved hematoma (1/59) and fistula (2/59). The results of this study suggest that CT-guided PCD using a modified version of the Seldinger technique for deep-seated, small abscesses and poorly depicted fluid collections on an abdominal sonogram is useful in terms of accuracy and safety.

  1. Fast integrated intravascular photoacoustic/ultrasound catheter (United States)

    Choi, Changhoon; Cho, Seunghee; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Jang, Kiyuk; Kim, Chulhong


    In cardiology, a vulnerable plaque is considered to be a key subject because it is strongly related to atherosclerosis and acute myocardial infarction. Because conventional intravascular imaging devices exhibit several limitations with regard to vulnerable plaque detection, the need for an effective lipid imaging modality has been continuously suggested. Photoacoustic (PA) imaging is a medical imaging technique with a high level of ultrasound (US) resolution and strong optical contrast. In this study, we successfully developed an integrated intravascular photoacoustic/ultrasound (IV-PAUS) imaging system with a catheter diameter of 1.2 mm for lipid-rich atherosclerosis imaging. An Nd:YAG pulsed laser with an excitation wavelength of 1064 nm was utilized. IV-PAUS offers 5-mm depth penetration and axial and lateral PA imaging resolutions of 94 μm and 203 μm, respectively, as determined by imaging a 6-μm carbon fiber. We initially obtained 3-dimensional (3D) co-registered PA/US images of metal stents. Subsequently, we successfully obtained 3D coregistered PA/US ex vivo images using an iliac artery from a rabbit atherosclerosis model. Accordingly, lipid-rich plaques were sufficiently differentiated from normal tissue in the ex vivo experiment. We validated these findings histologically to confirm the lipid content.

  2. [Acupuncture therapy for regaining consciousness in terms of acupoint location, needle insertion and needle manipulation]. (United States)

    Meng, Xianggang; Gu, Wenlong; Ma, Fen; Du, Yuzheng; Zhao, Qi


    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.

  3. A pilot study to assess adductor canal catheter tip migration in a cadaver model. (United States)

    Leng, Jody C; Harrison, T Kyle; Miller, Brett; Howard, Steven K; Conroy, Myles; Udani, Ankeet; Shum, Cynthia; Mariano, Edward R


    An adductor canal catheter may facilitate early ambulation after total knee arthroplasty, but there is concern over preoperative placement since intraoperative migration of catheters may occur from surgical manipulation and result in ineffective analgesia. We hypothesized that catheter type and subcutaneous tunneling may influence tip migration for preoperatively inserted adductor canal catheters. In a male unembalmed human cadaver, 20 catheter insertion trials were divided randomly into one of four groups: flexible epidural catheter either tunneled or not tunneled; or rigid stimulating catheter either tunneled or not tunneled. Intraoperative patient manipulation was simulated by five range-of-motion exercises of the knee. Distance and length measurements were performed by a blinded regional anesthesiologist. Changes in catheter tip to nerve distance (p = 0.225) and length of catheter within the adductor canal (p = 0.467) were not different between the four groups. Two of five non-tunneled stimulating catheters (40 %) were dislodged compared to 0/5 in all other groups (p = 0.187). A cadaver model may be useful for assessing migration of regional anesthesia catheters; catheter type and subcutaneous tunneling may not affect migration of adductor canal catheters based on this preliminary study. However, future studies involving a larger sample size, actual patients, and other catheter types are warranted.

  4. Porous-wall hollow glass microspheres as carriers for biomolecules (United States)

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven


    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  5. Biodegradable hollow fibres for the controlled release of hormones

    NARCIS (Netherlands)

    Eenink, M.J.D.; Feijen, J.; Olijslager, J.; Albers, J.H.M.; Rieke, J.C.; Greidanus, P.J.


    Poly(l-lactide), (PLLA), hollow fibres were prepared using a dry-wet phase inversion spinning process. The effect of several spinning parameters (i.e. bore medium flow rate, spinning dope extrusion rate, fibre take-up rate, and spinning height) on the hollow fibre dimensions is reported. The use of

  6. Photoluminescence of hollow gold-silver bimetallic nanoparticles


    Weon-Sik Chae; Hee-Ok Lee; Seung-Lim Oh


    Hollow gold nanoparticles including silver were prepared by the galvanic replacement reaction of silver nanoparticles by gold. The resulting hollow gold-silver bimetallic nanoparticles show notable blue-green emissions, which are studied using steady-state and time-resolved spectroscopy.

  7. Fabrication of Closed Hollow Bulb Obturator Using Thermoplastic Resin Material

    Directory of Open Access Journals (Sweden)

    Bidhan Shrestha


    Full Text Available Purpose. Closed hollow bulb obturators are used for the rehabilitation of postmaxillectomy patients. However, the time consuming process, complexity of fabrication, water leakage, and discoloration are notable disadvantages of this technique. This paper describes a clinical report of fabricating closed hollow bulb obturator using a single flask and one time processing method for an acquired maxillary defect. Hard thermoplastic resin sheet has been used for the fabrication of hollow bulb part of the obturator. Method. After fabrication of master cast conventionally, bulb and lid part of the defect were formed separately and joined by autopolymerizing acrylic resin to form one sized smaller hollow body. During packing procedure, the defect area was loaded with heat polymerizing acrylic resin and then previously fabricated smaller hollow body was adapted over it. The whole area was then loaded with heat cure acrylic. Further processes were carried out conventionally. Conclusion. This technique uses single flask which reduces laboratory time and makes the procedure simple. The thickness of hollow bulb can be controlled and light weight closed hollow bulb prosthesis can be fabricated. It also minimizes the disadvantages of closed hollow bulb obturator such as water leakage, bacterial infection, and discoloration.

  8. Simple Spinning of Heterogeneous Hollow Microfibers on Chip. (United States)

    Yu, Yue; Wei, Wenbo; Wang, Yaqing; Xu, Cong; Guo, Yaqiong; Qin, Jianhua


    A novel and simple chip-based microfluidic strategy is proposed for continuously controlled spinning of desirable hollow microfibers. These fabricated fiber-shaped materials exhibit extraordinary morphological and structural complexity, as well as a heterogeneous composition. The resulting specific hollow microfibers have potential applications in numerous chemical and biomedical fields.

  9. Wet spinning of asymmetric hollow fibre membranes for gas separation

    NARCIS (Netherlands)

    Hof, van 't Jacob Adriaan


    This thesis describes the spinning and characterizatin of hollow fibre membranes for gas separation. The type of fibres studied here are made by a wet spinning process. A homogeneous solution is prepared, consisting of a polymer in a suitable organic solvent, and extruded as a hollow fibre. Both the

  10. Fabrication of Closed Hollow Bulb Obturator Using Thermoplastic Resin Material. (United States)

    Shrestha, Bidhan; Hughes, E Richard; Kumar Singh, Raj; Suwal, Pramita; Parajuli, Prakash Kumar; Shrestha, Pragya; Sharma, Arati; Adhikari, Galav


    Purpose. Closed hollow bulb obturators are used for the rehabilitation of postmaxillectomy patients. However, the time consuming process, complexity of fabrication, water leakage, and discoloration are notable disadvantages of this technique. This paper describes a clinical report of fabricating closed hollow bulb obturator using a single flask and one time processing method for an acquired maxillary defect. Hard thermoplastic resin sheet has been used for the fabrication of hollow bulb part of the obturator. Method. After fabrication of master cast conventionally, bulb and lid part of the defect were formed separately and joined by autopolymerizing acrylic resin to form one sized smaller hollow body. During packing procedure, the defect area was loaded with heat polymerizing acrylic resin and then previously fabricated smaller hollow body was adapted over it. The whole area was then loaded with heat cure acrylic. Further processes were carried out conventionally. Conclusion. This technique uses single flask which reduces laboratory time and makes the procedure simple. The thickness of hollow bulb can be controlled and light weight closed hollow bulb prosthesis can be fabricated. It also minimizes the disadvantages of closed hollow bulb obturator such as water leakage, bacterial infection, and discoloration.

  11. [Design of acupoint electric characteristic sensing needle]. (United States)

    Liu, Tang-yi; Yang, Hua-yuan; Kuai, Le; Gao, Ming


    The electric characteristics of acupoints have been confirmed by researchers at home and abroad. Because the traditional detection methods are various (mainly are different positions of the reference electrode), and they are influenced by many affective factors, with unstable results and bad repeatability, so the studies of the electric characteristics of acupoints are limited. The acupoint electric characteristic sensing needle is introduced in detail from its design, detection methods and so on, which can detects changes of the acupoint electric characteristics of channels and acupoints in different healthy states real-timely, dynamically and continuously. It not only can avoid those affective factors, and also the detective results are relatively stable and the repeatability is also better.

  12. Fine-needle aspiration cytology in fibromatoses. (United States)

    Zaharopoulos, P; Wong, J Y


    Fine-needle aspiration (FNA) cytology was performed in seven cases of fibromatosis of variable types with tumorous clinical presentation. These included: four cases of musculoaponeurotic fibromatosis, two in posterior neck muscles, one in anterior neck muscles and one in intercostal muscles; one case of fibromatosis of the breast; and two cases of fibromatosis colli in neonates. In all cases the specimens contained connective tissue with many fibroblast-like cells, lacking features which could indicate a malignant lesion. The findings in these cases indicate that, although by FNA cytology in fibromatoses a specific diagnosis for each pathologic entity may not be easily reached, in the proper clinical setting the cytologic findings can be of sufficient relevance to offset the need for an open tissue biopsy, where there are valid reasons against a surgical intervention.

  13. Hollow micro string based calorimeter device

    DEFF Research Database (Denmark)


    The present invention relates to a micron-scale calorimeter and a calorimetry method utilizing the micron-scale calorimeter. In accordance with the invention, there is provided a micron-scale calorimeter comprising a micro-channel string, being restrained at at least two longitudinally distanced...... positions so as to form a free released double clamped string in-between said two longitudinally distanced positions said micro-channel string comprising a microfluidic channel having a closed cross section and extending in the longitudinal direction of the hollow string, acoustical means adapted...

  14. Hollow-Cathode Source Generates Plasma (United States)

    Deininger, W. D.; Aston, G.; Pless, L. C.


    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  15. Nonlinear sequential laminates reproducing hollow sphere assemblages (United States)

    Idiart, Martín I.


    A special class of nonlinear porous materials with isotropic 'sequentially laminated' microstructures is found to reproduce exactly the hydrostatic behavior of 'hollow sphere assemblages'. It is then argued that this result supports the conjecture that Gurson's approximate criterion for plastic porous materials, and its viscoplastic extension of Leblond et al. (1994), may actually yield rigorous upper bounds for the hydrostatic flow stress of porous materials containing an isotropic, but otherwise arbitrary, distribution of porosity. To cite this article: M.I. Idiart, C. R. Mecanique 335 (2007).

  16. Anti-resonant hexagram hollow core fibers. (United States)

    Hayes, John R; Poletti, Francesco; Abokhamis, Mousavi S; Wheeler, Natalie V; Baddela, Naveen K; Richardson, David J


    Various simple anti-resonant, single cladding layer, hollow core fiber structures are examined. We show that the spacing between core and jacket glass and the shape of the support struts can be used to optimize confinement loss. We demonstrate the detrimental effect on confinement loss of thick nodes at the strut intersections and present a fabricated hexagram fiber that mitigates this effect in both straight and bent condition by presenting thin and radially elongated nodes. This fiber has loss comparable to published results for a first generation, multi-cladding ring, Kagome fiber with negative core curvature and has tolerable bend loss for many practical applications.


    Institute of Scientific and Technical Information of China (English)

    Cai Jinbiao; Chen Weiqiu; Ye Guiru; Ding Haojiang


    An exact 3D analysis of free vibration of a piezoceramic hollow sphere submerged in a compressible fluid is presented in this paper.A separation method is adopted to simplify the basic equations for spherically isotropic piezoelasticity.It is shown that there are two independent classes of vibration.The first one is independent of the fluid medium as well as the electric field,while the second is associated with both the fluid parameter and the piezoelectric effect.Exact frequency equations are derived and numerical results are obtained.

  18. A study of outcome and complications associated with temporary hemodialysis catheters in a Nigerian dialysis unit

    Directory of Open Access Journals (Sweden)

    Christiana Oluwatoyin Amira


    Full Text Available Hemodialysis (HD catheters are commonly used as temporary vascular access in patients with kidney failure who require immediate HD. The use of these catheters is limited by complications such as infections, thrombosis resulting in poor blood flow. We studied the complications and outcomes of nontunneled catheters used for vascular access in our dialysis unit. The records of all patients, with renal failure who were dialyzed over a two-year period and had a double lumen nontunneled catheter inserted, were retrieved. Catheter insertion was carried out under ultrasound guidance using the modified Seldinger technique. The demographic data of patients, etiology of chronic kidney disease, and complications and outcomes of these catheters were noted. Fifty-four patients with mean age 43.7 ± 15.8 years had 69 catheters inserted for a cumulative total of 4047 catheter-days. The mean catheter patency was 36.4 ± 37.2 days (range: 1-173 days. Thrombosis occluding the catheters was the most common complication and occurred in 58% of catheters leading to catheter malfunction, followed by infections in18.8% of catheters. During follow-up, 30 (43.5% catheters were removed, 14 (20.3% due to catheter malfunction, eight (11.6% due to infection, five (7.2% elective removal, and three (4.3% due to damage. Thrombotic occlusion of catheters was a major limiting factor to the survival of HD catheters. Improvement in catheter patency can be achieved with more potent lock solutions.

  19. Remote Electromagnetic Vibration of Steerable Needles for Imaging in Power Doppler Ultrasound. (United States)

    Cabreros, Sarah S; Jimenez, Nina M; Greer, Joseph D; Adebar, Troy K; Okamura, Allison M


    Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle.

  20. Skin Blood Perfusion and Cellular Response to Insertion of Insulin Pen Needles With Different Diameters

    DEFF Research Database (Denmark)

    Præstmark, Kezia Ann; Stallknecht, Bente Merete; Bo Jensen, Casper;


    Today most research on pen needle design revolves around pain perception statements through clinical trials, but these are both costly, timely, and require high sample sizes. The purpose of this study was to test if tissue damage, caused by different types of needles, can be assessed by evaluating...... 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......, 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...

  1. Open Surgical Insertion of Tenkchoff Straight Catheter Without Guide Wire

    Institute of Scientific and Technical Information of China (English)

    Shi-feng Yang; Wu-jun Xue; Ai-ping Yin; Li-yi Xie; Wan-hong Lu


    Objective To compare the clinical outcomes of open surgical peritoneal dialysiscatheter(PDC) insertion with guide wireand the outcomesof PDC insertion without guide wire.Methods Data of the patients receiving open surgical Tenkchoff straight catheter insertion in our department from January 2005 to January 2011 were retrospectively analyzed.The 117 patients in whom PDC insertion was conducted with the guidance of guide wire were enrolled into group A, and the 121 cases receiving PDC insertion without guide wire wereenrolled into group B.The incidences of post-operative complications (catheter obstruction,catheter displacement, bloody dialysate, and dialysate leakage), catheter survival, and patientsurvival rates were compared between the 2 groups.Results The baseline characteristics (gender, age, body mass index, prothrombin time,activated partialthromboplastin time,platelet count,serum creatinine,follow-up time,primarydiseases, and outcomes) of the 2 groups were comparable (allP>0.05). In post-operativecomplications, only the incidence of early bloody dialysate showed significant difference, being16.2% in groupA and 7.4% in group B (P=0.04). Catheter and patient survival rates werenot significantly different between the two groups. Overweight patientsshowed a higherincidence of catheter obstruction compared with normal weight patients [16.0% (4/25) vs. 3.3% (7/213),P=0.02], but no differencesin post-operative complications werefound among overweight patientsbetween the 2 groups.Conclusions Open surgical Tenkchoff straightcatheterinsertion without guide wire does not lead to higher risk of post-operative complications and catheter removal. It may be an alternativeoption when guide wire is not available.

  2. Knowledge of nursing students about central venous catheters

    Directory of Open Access Journals (Sweden)

    Mlinar Suzana


    Full Text Available Background/Aim. Central venous catheters (CVC are at the crucial importance, particulary in the intensive therapy units. In order to handle a CVC safely, nursing students need to acquire theoretical and practical knowledge during the course of their studies. The aim of the study was to establish theoretical knowledge of nursing students about the procedures of nurses in placing and removing a central venous catheter (CVC, dressing the catheter entry point, the reasons for measuring central venous pressure (CVP, possible complications and risk factors for developing infections related to CVC. Methods. The questionnaire developed specifically for this cross-sectionl study was handed out to 87 full-time students and 57 part-time students. Results. The results show that all the surveyed nursing students know why chest radiography is carried out when inserting a catheter, have relatively good knowledge of CVC insertion points, procedures carried out in case of a suspected catheter sepsis and complications and risk factors for the development of infections related to CVC. However, the study show that the majority of students have insufficient knowledge of the procedures accompanying insertion of a catheter, signs that indicate correct functioning of CVC, frequency of flushing a catheter when it is not in use and the reasons for introducing an implanted CVC. Conclusion. Based on the results of the study it can be concluded that the second-year nursing students have insufficient knowledge of CVC. In order to correctly and safely handle a CVC, good theoretical knowledge and relevant practical experience are needed. The authors therefore believe that, in future, the classes should be organized in smaller groups with step-by-step demonstrations of individual procedures in handling a CVC, and the students encouraged to learn as actively as possible.

  3. Self-templated chemically stable hollow spherical covalent organic framework (United States)

    Kandambeth, Sharath; Venkatesh, V.; Shinde, Digambar B.; Kumari, Sushma; Halder, Arjun; Verma, Sandeep; Banerjee, Rahul


    Covalent organic frameworks are a family of crystalline porous materials with promising applications. Although active research on the design and synthesis of covalent organic frameworks has been ongoing for almost a decade, the mechanisms of formation of covalent organic frameworks crystallites remain poorly understood. Here we report the synthesis of a hollow spherical covalent organic framework with mesoporous walls in a single-step template-free method. A detailed time-dependent study of hollow sphere formation reveals that an inside-out Ostwald ripening process is responsible for the hollow sphere formation. The synthesized covalent organic framework hollow spheres are highly porous (surface area ~1,500 m2 g-1), crystalline and chemically stable, due to the presence of strong intramolecular hydrogen bonding. These mesoporous hollow sphere covalent organic frameworks are used for a trypsin immobilization study, which shows an uptake of 15.5 μmol g-1 of trypsin.

  4. An Atomic Lens Using a Focusing Hollow Beam

    Institute of Scientific and Technical Information of China (English)

    夏勇; 印建平; 王育竹


    We propose a new method to generate a focused hollow laser beam by using an azimuthally distributed 2π-phase plate and a convergent thin lens, and calculate the intensity distribution of the focused hollow beam in free propagation space. The relationship between the waist w0 of the incident collimated Gaussian beam and the dark spot size of the focused hollow beam at the focal point, and the relationship between the focal length f of the thin lens and the dark spot size are studied respectively. The optical potential of the blue-detuned focused hollow beam for 85Rb atoms is calculated. Our study shows that when the larger waist w of the incident Gaussian beam and the shorter focal length f of the lens are chosen, we can obtain an extremely small dark spot size of the focused hollow beam, which can be used to form an atomic lens with a resolution of several angstroms.


    Institute of Scientific and Technical Information of China (English)

    郝冬梅; 王新灵; 朱卫华; 唐小真; 刘成岑; 施凯


    Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St-BA-MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two-step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).

  6. Needle steering for robot-assisted insertion into soft tissue: A survey (United States)

    Gao, Dedong; Lei, Yong; Zheng, Haojun


    Needle insertion is a common surgical procedure used in diagnosis and treatment. The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on needle insertion. It is necessary to summarize and analyze the existing results to promote the future development of theories and applications of needle insertion. Thus, a survey of the state of the art of research is presented on algorithms of needle steering techniques, the surgical robots and devices. Based on the analysis of the needle insertion procedure, the concept of needle steering is defined as a kinematics problem, which is to place the needle at the target and avoid the obstacles. The needle steering techniques, including the artificial potential field method and the nonholonomic model, are introduced to control the needles for improving the accuracy. Based on the quasi-static thinking, the virtual spring model and the cantilever-beam model are developed to calculate the amount of needle deflection and generate the needle path. The phantoms instead of the real tissue are used to verify the models mentioned in most of the experimentations. For the desired needle trajectories, the image-guided robotic devices and some novel needles are presented to achieve the needle steering. Finally, the challenges are provided involving the controllability of the long flexible needle and the properties of soft tissue. The results and investigations can be used for further study on the precision and accuracy of needle insertion.

  7. Comparison of a needle-free high-pressure injection system with needle-tipped injection of intracavernosal alprostadil for erectile dysfunction. (United States)

    Harding, L M; Adeniyi, A; Everson, R; Barker, S; Ralph, D J; Baranowski, A P


    Patients identified from hospital records as using alprostadil injections for erectile dysfunction were invited to take part in this open crossover study. On alternate weeks eight patients were given intracavernosal needle injections and transdermal needle-free injection of alprostadil in a randomized order. Efficacy of injection and associated pain were assessed and compared for the two methods. Pain produced during injection was significantly greater with the needle-free system than with the needle-tipped injection whilst efficacy was significantly less. Bruising was reported in all except one patient following needle-free injection only. Patient ratings of the needle-free injector were significantly lower than ratings for needle-tipped alprostadil delivery and when asked to express a preference, every patient chose the needle-tipped injection over the needle-free device.

  8. Development of plasma needle to be used for biomedical applications (United States)

    Bora, B.; Jain, J.; Inestrosa-Izurieta, M. J.; Avaria, G.; Moreno, J.; Pavez, C.; Marcelain, K.; Armisen, R.; Soto, L.


    Plasma needle is a novel design of a plasma source at atmospheric pressure to achieve a non-thermal plasma jet. The advantage of the plasma needle is that it can be operated in open air, outside a vessel. The plasma that is generated with the plasma needle is small (about one millimetre) and non-thermal, the temperature of the neutral particles and ions is in about room temperature and suitably can interact with living biological cell without damaging the cell. In this work, we report the development of a plasma needle, which is operated by a dc power source and produced a stable plasma jet on water surface. Argon gas is used to operate the plasma needle. The preliminary electrical diagnostics of the plasma needle shows that the discharge is filamentary in nature. For diagnostic of the plasma jet produced by the developed plasma needle, the produced plasma jet is directed to water surface and characterization are carried out by means of electrical discharge characteristics and optical emission spectroscopy. In this work, preliminary results of the diagnostic will be presented.

  9. Image Guidance of Flexible Tip-Steerable Needles (United States)

    Kallem, Vinutha; Cowan, Noah J


    Image guidance promises to improve targeting accuracy and broaden the scope of medical procedures performed with needles. This paper takes a step toward automating the guidance of a flexible tip-steerable needle as it is inserted into human tissue. We build upon a previously proposed nonholonomic model of needles that derive steering from asymmetric bevel forces at the tip. The bevel-tip needle is inserted and rotated at its base in order to steer it in six degrees of freedom. As a first step for control, we show that the needle tip can be automatically guided to a planar slice of tissue as it is inserted. Our approach keeps the physician in the loop to control insertion speed. The distance of the needle tip position from the plane of interest is used to drive an observer-based feedback controller which we prove is locally asymptotically stable. Numerical simulations demonstrate a large domain of attraction and robustness of the controller in the face of parametric uncertainty and measurement noise. Physical experiments with tip-steerable Nitinol needles inserted into a transparent plastisol tissue phantom under stereo image guidance validate the effectiveness of our approach. PMID:20431694

  10. In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle (United States)

    Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun


    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.

  11. Comparison of a new aspiration needle device and the Quick-Core biopsy needle for transjugular liver biopsy

    Institute of Scientific and Technical Information of China (English)

    Toru Ishikawa; Tomoteru Kamimura; Hiroteru Kamimura; Atsunori Tsuchiya; Tadayuki Togashi; Kouji Watanabe; Kei-ichi Seki; Hironobu Ohta; Toshiaki Yoshida; Noriko Ishihara


    AIM: To evaluate sample adequacy, safety, and needle passes of a new biopsy needle device compared to the Quick-Core biopsy needle for transjugular liver biopsy in patients affected by liver disease.METHODS: Thirty consecutive liver-disease patients who had major coagulation abnormalities and/or relevant ascites underwent transjugular liver biopsy using either a new needle device (18 patients) or the Quick-Core biopsy needle (12 patients). The length of the specimens was measured before fixation. A pathologist reviewed the histological slides for sample adequacy and pathologic diagnoses. The two methods' specimen adequacy and complication rates were assessed.RESULTS: Liver biopsies were technically successful in all 30 (100%) patients, with diagnostic histological core specimens obtained in 30 of 30 (100%) patients, for an overall success rate of 100%. With the new device,18 specimens were obtained, with an average of 1.1passes per patient. Using the Quick-Core biopsy needle,12 specimens were obtained, with an average of 1.8passes per patient. Specimen length was significantly longer with the new needle device than with the QuickCore biopsy needle (P < 0.05). The biopsy tissue was not fragmented in any of the specimens with the new aspiration needle device, but tissue was fragmented in 3 of 12 (25.0%) specimens obtained using the Quick-Core biopsy needle. Complications included cardiac arrhythmia in 3 (10.0%) patients, and transient abdominal pain in 4 (13.3%) patients. There were no cases of subcapsular hematoma, hemoperitoneum, or sepsis, and there was no death secondary to the procedure. In particular, no early or delayed major procedure-related complications were observed in any patient.CONCLUSION: Transjugular liver biopsy is a safe and effective procedure, and there was significant difference in the adequacy of the specimens obtained using the new needle device compared to the QuickCore biopsy needle. Using the new biopsy needle device,the specimens showed

  12. Characteristics of Children Who Undergo Intraosseous Needle Placement. (United States)

    Reuter-Rice, Karin; Patrick, Dana; Kantor, Elizabeth; Nolin, Cathy; Foley, Jennifer


    Intraosseous (IO) access is a standard of care for pediatric emergencies in the absence of conventional intravenous access. Intraosseous needles provide access for resuscitation fluids and medications and are often placed in the emergency department. However, there are no studies to date that describe the characteristics of pediatric IO needle recipients or their dispositions and outcomes. This study examined the characteristics and disposition of children following IO needle placement by prehospital and emergency room teams before being transported to a children's hospital. We conducted a retrospective descriptive analysis of pediatric patients who had an IO needle placed as a part of their transport care. Data was extracted from a Level 1 trauma tertiary care children's hospital transport database from 1993 to 2009. We measured diagnosis, insertion reason, insertion time (day vs. night shift), complications, and disposition of patients after IO needle placement. There were 143 eligible patients in the study; 65% were males. Mean patient's age was 1.2 years (range: 0.01-13 years). Intraosseous needles were placed most often for patients with cardiopulmonary compromise. Of the 143 patients transported, 53% (n = 76) were placed for no intravenous access and 34% (n = 49) were placed for nonperfusing rhythm. The majority of the IO needles were placed during the daytime (0700-1900 hr), and most patients experienced no complications (n = 67; 47%). However, of those who experienced a complication, 27% were due to infiltration of the IO needle. Of those admitted to hospital, 58% (n = 83) were ultimately discharged home. Intraosseous access provides a safe and reliable method for rapidly achieving a route for administration of medications, fluids and blood products. It is a lifesaving measure with most IO needles successfully placed by referring facilities prior to transport, with few reported complications.

  13. A novel curvature-controllable steerable needle for percutaneous intervention. (United States)

    Bui, Van Khuyen; Park, Sukho; Park, Jong-Oh; Ko, Seong Young


    Over the last few decades, flexible steerable robotic needles for percutaneous intervention have been the subject of significant interest. However, there still remain issues related to (a) steering the needle's direction with less damage to surrounding tissues and (b) increasing the needle's maximum curvature for better controllability. One widely used approach is to control the fixed-angled bevel-tip needle using a "duty-cycle" algorithm. While this algorithm has shown its applicability, it can potentially damage surrounding tissue, which has prevented the widespread adoption of this technology. This situation has motivated the development of a new steerable flexible needle that can change its curvature without axial rotation, while at the same time producing a larger curvature. In this article, we propose a novel curvature-controllable steerable needle. The proposed robotic needle consists of two parts: a cannula and a stylet with a bevel-tip. The curvature of the needle's path is controlled by a control offset, defined by the offset between the bevel-tip and the cannula. As a result, the necessity of rotating the whole needle's body is decreased. The duty-cycle algorithm is utilized to a limited degree to obtain a larger radius of curvature, which is similar to a straight path. The first prototype of 0.46 mm (outer diameter) was fabricated and tested with both in vitro gelatin phantom and ex vivo cow liver tissue. The maximum curvatures measured 0.008 mm(-1) in 6 wt% gelatin phantom, 0.0139 mm(-1) in 10 wt% gelatin phantom, and 0.0038 mm(-1) in cow liver. The experimental results show a linear relationship between the curvature and the control offset, which can be utilized for future implementation of this control algorithm.

  14. Sharp beveled tip hollow microneedle arrays fabricated by LIGA and 3D soft lithography with polyvinyl alcohol (United States)

    Pérennès, F.; Marmiroli, B.; Matteucci, M.; Tormen, M.; Vaccari, L.; Di Fabrizio, E.


    This paper describes a fabrication process of hollow microneedle arrays with a sharp beveled tip for transdermal drug delivery. A master is fabricated through a double deep x-ray lithography process. First, a polymethylmethacrylate (PMMA) sheet is exposed to produce single PMMA parts with a sawtooth profile. The tip angle of each tooth determines the final tip angle of the microneedles. The PMMA parts are assembled and glued on a conductive substrate and then exposed through a second x-ray mask containing an array of hollow triangles as absorbing structures. A metal layer is then electrodeposited around the needles in order to form the future base of the array. A polyvinyl alcohol (PVA) solution is cast on top of the master to form a negative mold of the microneedle array after a low temperature curing and peel-off steps. A liquid PMMA solution is cast on top of the PVA negative mold and after the full PMMA polymerization the PVA is dissolved in water. This fabrication method can be performed in a non-clean room environment and requires little instrumentation. It is therefore compatible with a low-cost mass-fabrication scheme.

  15. High-pressure hollow cathode discharges (United States)

    Schoenbach, Karl H.; El-Habachi, Ahmed; Shi, Wenhui; Ciocca, Marco


    Reducing the diameter of the cathode hole in a plane anode - hollow cathode geometry to 0963-0252/6/4/003/img1m has allowed us to generate direct current discharges in argon at atmospheric pressure. Up to pressure times cathode hole diameter (pD) values of approximately 5 Torr cm, and at sub-mA currents, glow discharges (predischarges) are observed with a shape which is determined by the vacuum electric field. In the same pD range, but at higher currents of up to approximately 4 mA, the discharges are of the hollow cathode discharge type. At pD values exceeding 5 Torr cm the predischarges turn into surface discharges along the mica spacer between the electrodes. At currents > 4 mA filamentary, pulsed discharges are observed. Qualitative information on the electron energy distribution in the microdischarges has been obtained by studying the VUV emission from ionized argon atoms and the argon excimer radiation at 130 nm. The results of the spectral measurements indicate the presence of a relatively large concentration of electrons with energies > 15 eV over the entire pressure range. The fact that the current - voltage characteristic of the microdischarges has a positive slope over much of the current range where excimer radiation is emitted indicates the possibility of forming arrays of these discharges and using them in flat panel excimer lamps.

  16. Metal-Matrix/Hollow-Ceramic-Sphere Composites (United States)

    Baker, Dean M.


    A family of metal/ceramic composite materials has been developed that are relatively inexpensive, lightweight alternatives to structural materials that are typified by beryllium, aluminum, and graphite/epoxy composites. These metal/ceramic composites were originally intended to replace beryllium (which is toxic and expensive) as a structural material for lightweight mirrors for aerospace applications. These materials also have potential utility in automotive and many other terrestrial applications in which there are requirements for lightweight materials that have high strengths and other tailorable properties as described below. The ceramic component of a material in this family consists of hollow ceramic spheres that have been formulated to be lightweight (0.5 g/cm3) and have high crush strength [40.80 ksi (.276.552 MPa)]. The hollow spheres are coated with a metal to enhance a specific performance . such as shielding against radiation (cosmic rays or x rays) or against electromagnetic interference at radio and lower frequencies, or a material to reduce the coefficient of thermal expansion (CTE) of the final composite material, and/or materials to mitigate any mismatch between the spheres and the matrix metal. Because of the high crush strength of the spheres, the initial composite workpiece can be forged or extruded into a high-strength part. The total time taken in processing from the raw ingredients to a finished part is typically 10 to 14 days depending on machining required.

  17. Hollow Pollen Shells to Enhance Drug Delivery

    Directory of Open Access Journals (Sweden)

    Alberto Diego-Taboada


    Full Text Available Pollen grain and spore shells are natural microcapsules designed to protect the genetic material of the plant from external damage. The shell is made up of two layers, the inner layer (intine, made largely of cellulose, and the outer layer (exine, composed mainly of sporopollenin. The relative proportion of each varies according to the plant species. The structure of sporopollenin has not been fully characterised but different studies suggest the presence of conjugated phenols, which provide antioxidant properties to the microcapsule and UV (ultraviolet protection to the material inside it. These microcapsule shells have many advantageous properties, such as homogeneity in size, resilience to both alkalis and acids, and the ability to withstand temperatures up to 250 °C. These hollow microcapsules have the ability to encapsulate and release actives in a controlled manner. Their mucoadhesion to intestinal tissues may contribute to the extended contact of the sporopollenin with the intestinal mucosa leading to an increased efficiency of delivery of nutraceuticals and drugs. The hollow microcapsules can be filled with a solution of the active or active in a liquid form by simply mixing both together, and in some cases operating a vacuum. The active payload can be released in the human body depending on pressure on the microcapsule, solubility and/or pH factors. Active release can be controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell.

  18. A New Flavonoid in Pine Needles of Cedrus deodara

    Institute of Scientific and Technical Information of China (English)

    LIU Dong-yan; SHI Xiao-feng; WANG Dong-dong; MA Qu-huan; ZHANG Jun-min; LI Chong


    Objective To study the chemical constituents of flavonoids in pine needles of Cedrus deodara.Methods Flavonoids were isolated and purified from ethyl acetate extract of pine needles by chromatography on silica gel and Sephadex LH-20.Their structures were identified on the basis of spectroscopic analysis and chemical evidence.Results Five flavonoids were isolated and purified.Their structures were identified as cedrusone A(1),myricetin(2),2R,3R-dihydromyricetin(3),quercctin(4),and 2R,3R-dihydroquercetin(5).Conclusion Compound 1 is a new compound.Compounds 2-5 are isolated from pine needles of this genus for the first time.

  19. Diagenesis of conifer needles in a coastal marine environment (United States)

    Hedges, John I.; Weliky, K.


    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

  20. Rat indwelling urinary catheter model of Candida albicans biofilm infection. (United States)

    Nett, Jeniel E; Brooks, Erin G; Cabezas-Olcoz, Jonathan; Sanchez, Hiram; Zarnowski, Robert; Marchillo, Karen; Andes, David R


    Indwelling urinary catheters are commonly used in the management of hospitalized patients. Candida can adhere to the device surface and propagate as a biofilm. These Candida biofilm communities differ from free-floating Candida, exhibiting high tolerance to antifungal therapy. The significance of catheter-associated candiduria is often unclear, and treatment may be problematic considering the biofilm drug-resistant phenotype. Here we describe a rodent model for the study of urinary catheter-associated Candida albicans biofilm infection that mimics this common process in patients. In the setting of a functioning, indwelling urinary catheter in a rat, Candida proliferated as a biofilm on the device surface. Characteristic biofilm architecture was observed, including adherent, filamentous cells embedded in an extracellular matrix. Similar to what occurs in human patients, animals with this infection developed candiduria and pyuria. Infection progressed to cystitis, and a biofilmlike covering was observed over the bladder surface. Furthermore, large numbers of C. albicans cells were dispersed into the urine from either the catheter or bladder wall biofilm over the infection period. We successfully utilized the model to test the efficacy of antifungals, analyze transcriptional patterns, and examine the phenotype of a genetic mutant. The model should be useful for future investigations involving the pathogenesis, diagnosis, therapy, prevention, and drug resistance of Candida biofilms in the urinary tract.

  1. Development of a balloon volume sensor for pulsating balloon catheters. (United States)

    Nolan, Timothy D C; Hattler, Brack G; Federspiel, William J


    Helium pulsed balloons are integral components of several cardiovascular devices, including intraaortic balloon pumps (IABP) and a novel intravenous respiratory support catheter. Effective use of these devices clinically requires full inflation and deflation of the balloon, and improper operating conditions that lead to balloon under-inflation can potentially reduce respiratory or cardiac support provided to the patient. The goal of the present study was to extend basic spirographic techniques to develop a system to dynamically measure balloon volumes suitable for use in rapidly pulsating balloon catheters. The dynamic balloon volume sensor system (DBVSS) developed here used hot wire anemometry to measure helium flow in the drive line from console to catheter and integrated the flow to determine the volume delivered in each balloon pulsation. An important component of the DBVSS was an algorithm to automatically detect and adjust flow signals and measured balloon volumes in the presence of gas composition changes that arise from helium leaks occurring in these systems. The DBVSS was capable of measuring balloon volumes within 5-10% of actual balloon volumes over a broad range of operating conditions relevant to IABP and the respiratory support catheter. This includes variations in helium concentration from 70-100%, pulsation frequencies from 120-480 beats per minute, and simulated clinical conditions of reduced balloon filling caused by constricted vessels, increased driveline, or catheter resistance.

  2. Catheter-related infection in gastrointestinal fistula patients

    Institute of Scientific and Technical Information of China (English)

    Ge-Fei Wang; Jian-An Ren; Jun Jiang; Cao-Gan Fan; Xin-Bo Wang; Jie-Shou Li


    AIM: To study the incidence, bacterial spectrum and drug sensitivity of catheter-related infection (CRI) in gastrointestinal fistula patients.METHODS: A total of 216 patients with gastrointestinal fistulae during January 1998 to April 2001 were studied retrospectively. Two hundred and sixteen catheters of the 358 central venous catheters used in 216 gastrointestinal fistula patients were sent for microbiology analysis.RESULTS: Ninety-five bacteria were cultivated in 88catheters (24.6%). There were 54 Gram-negative bacteria (56.8%), 35 Gram-positive bacteria (36.8%), and 6 fungi (6.4%). During the treatment of CRI, 20 patients changed to use antibiotics or antifungal, and all patients were cured.The mean time of catheters used was 16.9±13.0 d.CONCLUSION: CRI is still the common complication during total parenteral nutrition (TPN) treatment in patients with gastrointestinal fistulae, and Gram-negative bacteria are the main pathogens, and bacterial translocation is considered the common reason for CRI.

  3. Port- a- Cath Catheter placement by general surgery residents

    Directory of Open Access Journals (Sweden)

    F. Schlottmann


    Full Text Available In recent years an increasing incidence and prevalence of oncological diseases is observed, with a consequent increase in chemotherapies. In order to avoid repeated venipuncture of patients and toxicity in small veins during different cycles of treatment, devices that provide a permanent central venous access are used. The aim of this study was to evaluate the success and safety of port a cath devices inserted by surgery residents. A consecutive case series of patients in whom Port-a-CathTM catheter was placed by residents of surgery in the period from March 2009 to January 2014 were included. A total of 358 Port-a-CathTM catheters were inserted. Average age 58.7 years (16-88. Females 53.1%. Chemotherapy treatment for solid neoplasias (74.8% and for hematological diseases (25.2%. SThe different venous accesses were: Subclavian (67.6%, Cephalic (27.4%, external jugular (3.3%, internal jugular (1.7%. The morbidity rate was 5.3%, twelve patients with catheter-associated infection requiring the removal of it, 3 venous thrombosis with subsequent replacement of the catheter and 4 patients required pleural drainage. Port-a-CathTM catheter placement by residents is a safe and effective procedure for the administration of chemotherapy

  4. Heparin Leakage in Central Venous Catheters by Hemodynamic Transport (United States)

    Barbour, Michael; McGah, Patrick; Gow, Kenneth; Aliseda, Alberto


    Central venous catheters (CVCs), placed in the superior vena cava for hemodialysis, are routinely filled with heparin, an anticoagulant, while not in use to maintain patency and prevent thrombus formation at the catheter tip. However, the heparin-lock procedure places the patient at risk for systemic bleeding incidences, as heparin is known to leak into the blood stream. We propose that the driving mechanism behind heparin leakage is advective-diffusive transport due to the pulsatile blood flow surrounding the catheter tip. This novel hypothesis is based on Planar Laser Induced Fluorescence (PLIF) measurements of heparin transport from a CVC placed inside an in vitro pulsatile flow loop and validated with CFD simulations. The results show an initial, fast (catheter lumen, where concentration is still high, that is insufficient at replenishing the lost heparin at the tip. These results, which estimate leakage rates consistent with published in vivo data, predict that the concentration of heparin at the catheter tip is effectively zero for the majority of the interdialytic phase, rendering the heparin lock ineffective.

  5. Hemodialysis Catheter Heat Transfer for Biofilm Prevention and Treatment. (United States)

    Richardson, Ian P; Sturtevant, Rachael; Heung, Michael; Solomon, Michael J; Younger, John G; VanEpps, J Scott


    Central line-associated bloodstream infections (CLABSIs) are not easily treated, and many catheters (e.g., hemodialysis catheters) are not easily replaced. Biofilms (the source of infection) on catheter surfaces are notoriously difficult to eradicate. We have recently demonstrated that modest elevations of temperature lead to increased staphylococcal susceptibility to vancomycin and significantly soften the biofilm matrix. In this study, using a combination of microbiological, computational, and experimental studies, we demonstrate the efficacy, feasibility, and safety of using heat as an adjuvant treatment for infected hemodialysis catheters. Specifically, we show that treating with heat in the presence of antibiotics led to additive killing of Staphylococcus epidermidis with similar trends seen for Staphylococcus aureus and Klebsiella pneumoniae. The magnitude of temperature elevation required is relatively modest (45-50°C) and similar to that used as an adjuvant to traditional cancer therapy. Using a custom-designed benchtop model of a hemodialysis catheter, positioned with tip in the human vena cava as well as computational fluid dynamic simulations, we demonstrate that these temperature elevations are likely achievable in situ with minimal increased in overall blood temperature.

  6. Epidural fibrosis after permanent catheter insertion and infusion. (United States)

    Aldrete, J A


    Forty-six permanent epidural catheters and life-port units were implanted in 43 patients with severe, recurrent low back pain who had been considered not to be candidates for surgical intervention and in whom other therapeutic modalities had failed. Eight cases developed epidural fibrosis (EF). For analgesia, patients received either infusions with preservative-free solutions of fentanyl and bupivacaine or daily boluses of morphine and bupivacaine. Catheters remained from 75 days to 433 days. Signs of EF appeared from 21 days to 320 days after implantation. Pain at injection or resistance to injection were initial manifestations of EF, followed by poor, and eventually, nil analgesic effect. The epidural catheters were made of either polyamide, silicone, or polyurethane. Epidurograms revealed encapsulation, narrowing, and loculation of epidural space with gradually reduced spread of the contrast material. The occurrence of EF limits the permanency of implanted epidural catheters. The infusate does not cause this complication, which appears to be a foreign body reaction due to the presence of the catheter in the epidural space.

  7. Foley Catheter versus Vaginal Misoprostol for Labour Induction

    Directory of Open Access Journals (Sweden)

    Nasreen Noor


    Full Text Available Objectives. To compare the efficacy and safety of intravaginal misoprostol with transcervical Foley catheter for labour induction. Material and Methods. One hundred and four women with term gestation, with Bishop score < 4, and with various indications for labour induction were randomly divided into two groups. In Group I, 25 μg of misoprostol tablet was placed intravaginally, 4 hourly up to maximum 6 doses. In Group II, Foley catheter 16F was placed through the internal os of the cervix under aseptic condition and then inflated with 50 cc of sterile saline. Statistical analysis was done using SPSS software. Results. The induction to delivery interval was 14.03 ± 7.61 hours versus 18.40 ± 8.02 hours (p<0.01. The rate of vaginal delivery was 76.7% versus 56.8% in misoprostol and transcervical Foley catheter group, respectively. Uterine hyperstimulation was more common with misoprostol. Neonatal outcome was similar in both the groups. Conclusion. Intravaginal misoprostol is associated with a shorter induction to delivery interval as compared to Foley’s catheter and it increases the rate of vaginal delivery in cases of unripe cervix at term. Transcervical Foley catheter is associated with a lower incidence of uterine hyperstimulation during labour.

  8. Air Separation Using Hollow Fiber Membranes (United States)

    Huang, Stephen E.


    The NASA Glenn Research Center in partnership with the Ohio Aerospace Institute provides internship programs for high school and college students in the areas of science, engineering, professional administrative, and other technical areas. During the summer of 2004, I worked with Dr. Clarence T. Chang at NASA Glenn Research Center s combustion branch on air separation using hollow fiber membrane technology. . In light of the accident of Trans World Airline s flight 800, FAA has mandated that a suitable solution be created to prevent the ignition of fuel tanks in aircrafts. In order for any type of fuel to ignite, three important things are needed: fuel vapor, oxygen, and an energy source. Two different ways to make fuel tanks less likely to ignite are reformulating the fuel to obtain a lower vapor pressure for the fuel and or using an On Board Inert Gas Generating System (OBIGGS) to inert the Central Wing Tank. goal is to accomplish the mission, which means that the Air Separation Module (ASM) tends to be bulky and heavy. The primary goal for commercial aviation companies is to transport as much as they can with the least amount of cost and fuel per person, therefore the ASM must be compact and light as possible. The plan is to take bleed air from the aircraft s engines to pass air through a filter first to remove particulates and then pass the air through the ASM containing hollow fiber membranes. In the lab, there will be a heating element provided to simulate the temperature of the bleed air that will be entering the ASM and analysis of the separated air will be analyzed by a Gas Chromatograph/Mass Spectrometer (GC/MS). The GUMS will separate the different compounds in the exit streams of the ASM and provide information on the performance of hollow fiber membranes. Hopefully I can develop ways to improve efficiency of the ASM. different types of jet fuel were analyzed and data was well represented on SAE Paper 982485. Data consisted of the concentrations of over

  9. Placement of a Hemodialysis Catheter using the Dilated Right External Jugular Vein as a Primary Route

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mi Hyun [Dankook University Hospital, Cheonan (Korea, Republic of); Shin, Byung Seok [Chungnam National University Hospital, Daejeon (Korea, Republic of)


    To evaluate the feasibility that a dilated right external jugular vein (EJV) could be a primary venous access site for large bore hemodialysis catheter placement. Between January 2008 and April 2009, a total of 173 hemodialysis catheters (14.5 F) were placed. Among them, we evaluated the clinical data of 42 patients who underwent placement through a dilated right EJV. We evaluated technical success, duration of catheterization in days, and the presence of complications. Technical success was achieved for 41 patients (98%). Catheter placement was unsuccessful in one patient due to narrowing of the EJV. The catheter dwell time ranged between 14 and 305 days (mean; 76 days, total catheter days: 3,111 days). A total of 26 hemodialysis catheters were removed due to complications (n=2) and termination of hemodialysis via the hemodialysis catheter (n=24). There was air embolization (n=1) and catheter kinking (n=3) during procedures and catheter related infections (n=2) during the follow-up period. The incidence of catheter related infection was 0.06 per 100 catheter days. No cases of catheter malfunction or symptomatic venous thrombosis were observed. We suggest that a dilated right EJV could be considered as a preferred primary route for hemodialysis catheter placement with easy access

  10. Outcome of tunneled infusion catheters inserted via the right internal jugular vein

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Wook; Do, Young Soo; Choo, Sung Wook; Yoo, Wi Kang; Choo, In Wook [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Jae Hyung [Sanggye Paik Hospital, Inje University, Seoul (Korea, Republic of)


    To assess the outcome of tunneled central venous catheter placement via the right internal jugular vein. Between June 2001 and May 2002, 670 consecutive Hickman catheters were placed in 654 patients via the right internal jugular vein. The procedural complications arising and follow-up data obtained from May to July 2002 were evaluated. The technical success rate for catheter placement was 99.9% (669/670). Procedural complications were limited to eight cases (1.2%), including three pneumothoraces, one early migration of the catheter, one clinically unimportant air embolism, one catheter injury, one catheter kinking and one primary malpositioning in the azygos vein. Catheter dwelling time ranged from 1 to 407 (mean 107.1) days. During the follow-up period, 416 catheter were removed for various reasons: treatment had ended (n=334), patients declined treatment or their drug regimen was changed (n=16), late complications arose (n=53), or other circumstances intervened (n=13). Late complications included 44 cases of catheter-related infection (6.6%), five of catheter migration (0.7%), two of catheter occlusion (0.3%), one of thrombophlebitis (0.15%), and one of catheter-related right atrial thrombosis (0.15%). Only one instance of symptomatic venous thrombosis or stenosis was noted, namely the one case of thrombophlebitis. Because the incidence of subsequent symptomatic venous thrombosis or stenosis is lower, the preferred route for tunneled central venous catheter placement is the right internal jugular vein.

  11. Comparison of outcomes between surgically placed and percutaneously placed peritoneal dialysis catheters: A retrospective study (United States)

    Sivaramakrishnan, R.; Gupta, S.; Agarwal, S. K.; Bhowmik, D.; Mahajan, S.


    There is lack of adequate data on comparison of outcomes between percutaneously placed peritoneal dialysis (PD) catheters inserted by nephrologists and PD catheters placed by surgeons. The aim of this study is to retrospectively analyze the outcomes of PD catheters inserted by surgeons (by open surgical or laparoscopic technique) and compare them with those inserted by nephrologists among ESRD patients who underwent elective PD catheter insertions between January 2009 and December 2012. The primary outcome measure was the proportion of catheters removed because of primary nonfunction. The secondary outcome measures were catheter survival, patient survival, and incidence of complications of catheter insertion. A total of 143 PD catheter insertions (88 by surgeons and 55 by nephrologists) performed in 132 patients were considered for the analysis. The primary nonfunction rate of PD catheter insertions in both groups was comparable (18.2% and 7.3%, P = 0.08). Break-in period was shorter in Group N (p = <0.001). No differences were noted in patient or catheter survival. Percutaneously placed PD catheters performed by nephrologists have comparable outcomes with surgically placed PD catheters among selected cases and have the advantage of lower costs, avoidance of operation theater scheduling issues, smaller incision length, and shorter break-in period. Therefore, more nephrologists should acquire the expertise on percutaneous PD catheter placement as it leads to lesser waiting times and better utilization of PD. PMID:27512299

  12. The selection of small forest hollows for pollen analysis in boreal and temperate forest regions

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Bradshaw, Richard H.W.


    Small forest hollows represent a specialised site type for pollen analysis, since they mainly record the vegetation within an approximate radius of 20-100 m from the hollow. We discuss how to choose the most appropriate small forest hollow for pollen analysis. Hollow size, site topography, location...

  13. Ultrasound guided fine-needle aspiration cytology of breast lesions


    C. Pagani; Coscia, D. R.; Dellabianca, C.; Bonardi, M.; Alessi, S.; Calliada, F.


    Breast biopsy consists in the collection of cells or tissue fragments from a breast lesion and their analysis by a pathologist. There are several types of breast biopsy defined on the basis of the type of needle used: fine-needle aspiration and biopsy performed with a spring-based needle. This article focuses on fine-needle aspiration performed under sonographic guidance.

  14. Bacterial Biofilms and Catheters: A Key to Understanding Bacterial Strategies in Catheter-Associated Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    J Curtis Nickel


    Full Text Available Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder’s mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.

  15. An in vitro urinary tract catheter system to investigate biofilm development in catheter-associated urinary tract infections. (United States)

    Dohnt, Katrin; Sauer, Marie; Müller, Maren; Atallah, Karin; Weidemann, Marina; Gronemeyer, Petra; Rasch, Detlev; Tielen, Petra; Krull, Rainer


    Biofilm development in urinary tract catheters is an often underestimated problem. However, this form of infection leads to high mortality rates and causes significant costs in health care. Therefore, it is important to analyze these biofilms and establish avoiding strategies. In this study a continuous flow-through system for the cultivation of biofilms under catheter-associated urinary tract infection conditions was established and validated. The in vitro urinary tract catheter system implies the composition of urine (artificial urine medium), the mean volume of urine of adults (1 mL min(-1)), the frequently used silicone catheter (foley silicon catheter) as well as the infection with uropathogenic microorganisms like Pseudomonas aeruginosa. Three clinical isolates from urine of catheterized patients were chosen due to their ability to form biofilms, their mobility and their cell surface hydrophobicity. As reference strain P. aeruginosa PA14 has been used. Characteristic parameters as biofilm thickness, specific biofilm growth rate and substrate consumption were observed. Biofilm thicknesses varied from 105±16 μm up to 246±67 μm for the different isolates. The specific biofilm growth rate could be determined with a non invasive optical biomass sensor. This sensor allows online monitoring of the biofilm growth in the progress of the cultivation.

  16. A European perspective on intravascular catheter-related infections

    DEFF Research Database (Denmark)

    Bouza, E; San Juan, R; Muñoz, P;


    The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology...... by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques....... Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p...

  17. The female experience of ISC with a silicone catheter. (United States)

    Logan, Karen


    Intermittent self-catheterisation (ISC) is a safe and effective treatment in the management of neuropathic bladder, voiding dysfunction and urinary incontinence in women. ISC has been shown to improve quality of life when used appropriately. It provides freedom for individuals who require bladder drainage as they can choose where and when to catheterise to empty the bladder. ISC requires minimum equipment, is a more discreet solution than an indwelling catheter and is relatively easy to teach in one patient visit. There are a range of different ISC catheters available on prescription. Many have been designed specifically for women and patient choice regarding product selection is an important consideration. This article describes a UK patient-satisfaction survey evaluating the female patient's perspective of learning ISC using a silicone intermittent catheter called HydroSil Go(™) that is manufactured by C.R. Bard, Inc.

  18. Energy efficient engine shroudless, hollow fan blade technology report (United States)

    Michael, C. J.


    The Shroudless, Hollow Fan Blade Technology program was structured to support the design, fabrication, and subsequent evaluation of advanced hollow and shroudless blades for the Energy Efficient Engine fan component. Rockwell International was initially selected to produce hollow airfoil specimens employing the superplastic forming/diffusion bonding (SPF/DB) fabrication technique. Rockwell demonstrated that a titanium hollow structure could be fabricated utilizing SPF/DB manufacturing methods. However, some problems such as sharp internal cavity radii and unsatisfactory secondary bonding of the edge and root details prevented production of the required quantity of fatigue test specimens. Subsequently, TRW was selected to (1) produce hollow airfoil test specimens utilizing a laminate-core/hot isostatic press/diffusion bond approach, and (2) manufacture full-size hollow prototype fan blades utilizing the technology that evolved from the specimen fabrication effort. TRW established elements of blade design and defined laminate-core/hot isostatic press/diffusion bonding fabrication techniques to produce test specimens. This fabrication technology was utilized to produce full size hollow fan blades in which the HIP'ed parts were cambered/twisted/isothermally forged, finish machined, and delivered to Pratt & Whitney Aircraft and NASA for further evaluation.

  19. Neonatal effect of venous indwelling needle puncture on different indwelling time%新生儿静脉留置针不同穿刺部位对留置效果的影响

    Institute of Scientific and Technical Information of China (English)

    何英萍; 鞠远凤


    目的:探讨新生儿不同部位静脉留置针对留置效果的影响。方法选择患儿90例,随机分为头皮静脉组、四肢静脉和颈外静脉组30例,比较穿刺成功率、留置时间、并发症发生情况。结果颈外静脉组穿刺成功率明显高于头皮静脉组和四肢静脉组,留置时间明显长(χ2=6.240,P=0.00;F=2.38,P=0.00);并发症发生率明显低(P<0.05)。结论对新生儿,颈静脉留置针具有较高的首次穿刺成功率、较低的并发症发生率及较长的留置时间。%Objective: To investigate the effect of emergency neonatal venous indwelling needle different puncture site on detaining effect.Methods: 90 cases of emergency newborn were selected and randomly divided into scalp vein group, limb vein and external jugular vein group,there were 30 cases, scalp vein group were used by scalp venous indwelling needle, limb vein group were used by limbs venous indwelling needle, external jugular vein group were used by external jugular vein indwelling needle, the first success rate of puncture, catheter time, puncture complications of three groups were compared.Results: The success rate of puncture of external jugular vein group was significantly higher than that of scalp venous indwelling catheter group or limb vein group, the indwelling time was significantly longer than that of scalp venous group and limb vein group (χ2=6.240, P=0.00; F=2.38,P=0.00); the jugular phlebitis and overall complication rate were lower than those of scalp venous group or limb vein group (P<0.05).Conclusion: To emergency newborn, indwelling time of jugular vein indwelling needle has higher success rate of first puncture ,lower complication incidence and longer catheter time, it can reduce nursing workload, improve clinical treatment effect, at the same time, relieve newborn pain and risk of infection.

  20. Concurrent fine needle aspirations and core needle biopsies: a comparative study of substrates for next-generation sequencing in solid organ malignancies. (United States)

    Roy-Chowdhuri, Sinchita; Chen, Hui; Singh, Rajesh R; Krishnamurthy, Savitri; Patel, Keyur P; Routbort, Mark J; Manekia, Jawad; Barkoh, Bedia A; Yao, Hui; Sabir, Sharjeel; Broaddus, Russell R; Medeiros, L Jeffrey; Staerkel, Gregg; Stewart, John; Luthra, Rajyalakshmi


    Minimally invasive procedures, such as fine needle aspiration and core needle biopsy, are commonly used for the diagnosis in solid organ malignancies. In the era of targeted therapy, it is crucial for molecular testing to be performed on these limited volume specimens. Although several recent studies have demonstrated the utility of small biopsy specimens for molecular testing, there remains debate as to whether core needle biopsy specimens are more reliable than fine needle aspiration for molecular studies. In this study, we reviewed concurrently acquired fine needle aspiration and core needle biopsy samples (n=24), and compared overall cellularity, tumor fraction, and the results of next-generation sequencing. All somatic mutations detected in core needle biopsy samples were also detected in fine needle aspiration samples. The estimated tumor fraction was significantly higher in fine needle aspiration smears than core needle biopsy samples (P=0.003), whereas the overall DNA yield from smears was significantly lower than that obtained from the core needle biopsy specimens (P=0.01). The normalized average amplicon coverage for the genes analyzed was significantly higher in cytology smears than paired core needle biopsy samples, with lower numbers of failed amplicons and higher overall mutation allelic frequencies seen in the former. We further evaluated 100 malignant fine needle aspiration and core needle biopsy samples, acquired concurrently, for overall cellularity and tumor fraction. Overall cellularity and tumor fraction of fine needle aspiration samples was significantly higher than concurrently acquired core needle biopsy samples (Pcore needle biopsy samples. Cytologic specimens, therefore, should be better integrated into routine molecular diagnostics workflow to maximize limited tissues for clinically relevant genomic testing.Modern Pathology advance online publication, 13 January 2017; doi:10.1038/modpathol.2016.228.


    Institute of Scientific and Technical Information of China (English)

    李建兰; 阎巍; 岳仍丽


    In this paper, a total of 18 cases of primary trigeminal neuralgia were treated with elongated needle. Of the 18 cases, 5 were male and 15 female, ranging in age from 27 to 58 years and in disease duration from 3 days to 8 years. Main acupoints used were Taiyang (EX-HN 5) to Xiaguan (ST 7, for penetration needling), Xiajiache, Fengchi (GB 20), Yanglingquan (GB 34) and Taichong (LR 3). The treatment was given once daily, with 12 sessions being a therapeutic course. After 2 courses of treatment, of the 18 cases, 10 cases were cured, 7 experienced improvement in pain and one failed in the treatment, with an effective rate of 94.4%. The key point for treating trigeminal neuralgia is applying penetrative needling from EX-HN 5 to ST 7 to achieve ideal needling sensations.

  2. Warm-Needling Technique for Peripheral Facial Paralysis

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan-nian; ZHOU Jing; SHAO Ming-hai


    Objective: To observe the therapeutic effects of warm-needling technique on peripheral facial paralysis. Methods: Warm-needling technique and electroacupuncture were employed to treat 30 cases of facial paralysis, respectively. The same acupoints, Cuanzhu(BL 2)towards Yuyao(Ex-HN 4), Yingxiang(LI 20) towards Xiaguan(ST 7), Taiyang(Ex-HN 5)towards Xuanlu(GB 5), Dicang(ST 4) towards Jiache(ST 6), and Chengjiang(CV 24) towards Daying(ST 5), were used. Results: After 33 treatments, the warm-needling technique has an effective rate of 83.3%, while the electroacupuncture 67.7%. Conclusion: The therapeutic effect of warm-needling technique was better than that of electroacupuncture method.

  3. [Quintessence of academician SHI Xue-min's acupoint needling method]. (United States)

    Yang, Ming-Xing


    Under guidance of the traditional theories of acupuncture and modern knowledge of anatomy and in combination with his long-term clinical practice and clinical researches, academician SHI Xue-min formulates scien tific and strict acupuncture methods and corresponding quantitative requirement for the acupoints for treatment of stroke and relative diseases and symptoms, including patient's posture, doctor's posture, angle of needle insertion, manipulation, amount of arrival of qi, etc. Correct grasping these needling methods of acupoints is a key to learn and understand SHI Xue-min's Acupuncture Science and "Xingnao Kaiqiao" needling method and quantitative acu puncture manipulation theory. In this paper, SHI Xue-min's partial experiences on needling acupoints are introduced.

  4. Percutaneous transhepatic biliary drainage using large needle: Complications and usefulness

    Energy Technology Data Exchange (ETDEWEB)

    Park, Noh Kyoung; Lim, Hyun Yang; Lee, Ji Yeon; Lee, Kil Jun; Tae, Seok; Shin, Kyoung Ja; Lee, Sang Chun [Seoul Red Cross Hospital, Seoul (Korea, Republic of)


    To analyse complications and to review usefulness of large needle(18G) in percutaneous transhepatic biliary drainage(PTBD). 46 patients underwent PTBD in 52 occasions using large needle. 44 of 46 patients had either definite or suspicious malignant biliary obstruction, and most patients were poor in general condition. Complications were classified as acute type if developed within 30 days and as delayed type if developed after 30 days. Acute type was subdivided into severe and mild forms. Severe forms of complications were death(5.8%), septicemia(3.8%), and bile peritonitis(1.9%). There were not different from the rate of complication in PTBD using fine needle but the procedure was much more simple. We PTBD using large needle is a simple and safe procedure for prompt bile decompression.

  5. Guidelines for processing and reporting of prostatic needle biopsies

    NARCIS (Netherlands)

    Th.H. van der Kwast (Theo); C. Lopes; C. Santonja; C.G. Pihl; I. Neetens; P. Martikainen (Pekka); S. di Lollo; L. Bubendorf; R.F. Hoedemaeker


    textabstractThe reported detection rate of prostate cancer, lesions suspicious for cancer, and prostatic intraepithelial neoplasia (PIN) in needle biopsies is highly variable. In part, technical factors, including the quality of the biopsies, the tissue processing, and histopatholo

  6. [Doctor HUANG Shi-ping's acupuncture with golden needles]. (United States)

    Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang


    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.


    Institute of Scientific and Technical Information of China (English)

    LIN Wen-jian


    In the present paper, the author sums up and analyzes descriptions about needle-insertion depth in Chinese classical medical book Huang Di Nei Jing (The Yellow Emperor's Internal Classic). In many chapters of Nei Jing, the needle-insertion depth is stressed to be various according to 1) the deficiency or excess of syndromes, 2) the patients' constitution, 3) the severity of disease, 4) the duration of disease, 5) the location of disease, 6) the patient's age, 7) the location of the needled acupoint, 8) the season, 9) the patient's temperament, 10) the pulse condition, 11) the state of "Deqi", and 12) the location of the running course of meridians. In addition, different kinds of diseases and different stages of diseases also need different depths of needle insertion, different manipulating skills and different stimulating quantity.


    Morphological differences between old growth and sapling (Pseudotsuga menziesii, (Mirb.) Franco) Douglas fir trees may extend to differences in needle anatomy. We used microscopy with image analysis to compare and quantify anatomical parameters in cross-sections of previous year...

  9. Ralph L. Huber, DMD: forgotten inventor of the "Tuohy" needle. (United States)

    Lubisich, Josef W


    The hypodermic needle popularized by Edward Tuohy, MD for use in his method of continuous spinal anesthesia has been incorrectly called the "Tuohy needle" since he first popularized it in 1945. It was recently determined that Ralph L. Huber, a Seattle dentist, was the inventor of this widely used needle. However, very little is known about Huber. There is no mention of him in the medical literature, and until recently, he was forgotten. Through the location of various primary sources, including the original needle point invented by Dr. Huber, this essay introduces the fascinating life of Dr. Huber, and also his personal notes about his inventions. Not only was he a prominent Seattle dentist, but also a prolific inventor.

  10. Nosocomial bacteremia and catheter infection by Bacillus cereus in an immunocompetent patient. (United States)

    Hernaiz, C; Picardo, A; Alos, J I; Gomez-Garces, J L


    We present a case of Bacillus cereus bacteremia and catheter infection in an immunocompetent patient subjected to abdominal surgery, who recovered following central catheter removal and treatment with piperacillin/tazobactam.

  11. Radiologic interventional retrieval of retained central venous catheter fragment in prematurity: case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jee Won; Jo, Jung Hyun; Park, Byeong Ho [College of Medicine, Dong-A University, Busan (Korea, Republic of)


    The fracture of a central venous catheter is a rare but potentially serious complication. Moreover, removal of the broken catheter pieces is considerably challenging, especially for premature infants. We report 3 case studies of the percutaneous transcatheter retrieval of broken catheter parts in 3 premature infants. We confirmed the location of the catheter fragments via a DSA venogram with diluted contrast media. Using the minimum amount of contrast, and extreme caution, we made certain no contrast-induced nephrotoxicity of air embolism occurred during catheter manipulation. In addition, when the broken fragment was curled or attached to the cardiac wall, we used a hook-shaped catheter to facilitate the capturing of the catheter with a loopsnare. This report demonstrates the feasibility of removing a retained catheter fragment in a premature infant using a percutaneous transcatheter approach.

  12. Adjacent central venous catheters can result in immediate aspiration of infused drugs during renal replacement therapy. (United States)

    Kam, K Y R; Mari, J M; Wigmore, T J


    Dual-lumen haemodiafiltration catheters enable continuous renal replacement therapy in the critically ill and are often co-located with central venous catheters used to infuse drugs. The extent to which infusions are immediately aspirated by an adjacent haemodiafiltration catheter remains unknown. A bench model was constructed to evaluate this effect. A central venous catheter and a haemodiafiltration catheter were inserted into a simulated central vein and flow generated using centrifugal pumps within the simulated vein and haemodiafiltration circuit. Ink was used as a visual tracer and creatinine solution as a quantifiable tracer. Tracers were completely aspirated by the haemodiafiltration catheter unless the infusion was at least 1 cm downstream to the arterial port. No tracer was aspirated from catheters infusing at least 2 cm downstream. Orientation of side ports did not affect tracer elimination. Co-location of central venous and haemodiafiltration catheters may lead to complete aspiration of infusions into the haemodiafilter with resultant drug under-dosing.

  13. Biofilm formation in long-term central venous catheters in children with cancer

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Fuursted, Kurt; Funch, Peter;


    Taurolidine has demonstrated inhibition of biofilm formation in vitro. The aim of this study was to compare the effect of catheter locking with taurolidine vs heparin in biofilm formation in central venous catheters. Forty-eight children with cancer were randomized to catheter locking by heparin (n...... = 22) or taurolidine (n = 26), respectively. After removal, catheters were examined by standardized scanning electron microscopy to assess quantitative biofilm formation. Biofilm was present if morphologically typical structures and bacterial cells were identified. Quantitative and semi......-quantitative cultures were also performed. Biofilm was identified in 23 of 26 catheters from the taurolidine group and 21 of 22 catheters from the heparin group. A positive culture was made of six of the catheters locked with taurolidine and heparin, respectively (p = 0.78). The rate of catheter-related bloodstream...

  14. Implementation of a children's hospital-wide central venous catheter insertion and maintenance bundle

    NARCIS (Netherlands)

    K. Helder MScN (Onno); R.F. Kornelisse (René); C. van der Starre (Cynthia); D. Tibboel (Dick); C.W.N. Looman (Caspar); R.M.H. Wijnen (René); M.J. Poley (Marten); E. Ista (Erwin)


    textabstractBackground: Central venous catheter-associated bloodstream infections in children are an increasingly recognized serious safety problem worldwide, but are often preventable. Central venous catheter bundles have proved effective to prevent such infections. Successful implementation requir

  15. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)


    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

  16. Evaluation of the safety of latrogenic lntestinal perforation during placement of percutaneous drainage catheter in rabbit

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choon Hyeong; Oh, Joo Hyung; Park, Ga Young; Shin, Hong Sub; Kim, In Sub; Yoon, Yup; Lee, Dong Ho; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)


    To evaluate the safety of transgression of the bowel during intraperitoneal percutaneous catheter placement in an animal model. Eight 8-F straight catheters were percutaneously inserted into the small and large bowel of eight rabbits. In four animals, the catheters were left in place until autopsy, whereas in the remaining four, the catheters were withdrawn five days after insertion. Autopsy was performed in all animals ten days after catheter placement, and gross and microscopic examination was carried out. Transgressing the bowel during intraperitoneal percutaneous catheter placement did not contribute to any clinically significant complications. At autopsy, there was no bowel leakage, peritonitis, or abscess, although peritoneal adhesions were found around the catheter tract. Although further study is warranted, our study with an animal model indicated that transgression of the intestine during percutaneous placement of an intraabdominal catheter did not produce significant complications.

  17. Comparison of complication rates between umbilical and peripherally inserted central venous catheters in newborns

    NARCIS (Netherlands)

    Arnts, I.J.J.; Bullens, L.M.; Groenewoud, J.M.M.; Liem, K.D.


    OBJECTIVE: To compare the complication rates between umbilical central venous catheters and peripherally inserted central venous catheters in newborns and to investigate whether other variables might increase complication rates. DESIGN: A retrospective observational study. SETTING: A Level III neona

  18. Clinical efficacy and safety of catheter ablation for atrial fibrillation in elderly patients

    Institute of Scientific and Technical Information of China (English)



    Objective To evaluate the clinical efficacy and safty of catheter ablation for atrial fibrillation in elderly patients.Methods From September 2008 to October 2011,a total of 420 consecutive patients undergoing cathete rablation

  19. The supraclavicular fossa ultrasound view for central venous catheter placement and catheter change over guidewire. (United States)

    Kim, Se-Chan; Klebach, Christian; Heinze, Ingo; Hoeft, Andreas; Baumgarten, Georg; Weber, Stefan


    The supraclavicular fossa ultrasound view can be useful for central venous catheter (CVC) placement. Venipuncture of the internal jugular veins (IJV) or subclavian veins is performed with a micro-convex ultrasound probe, using a neonatal abdominal preset with a probe frequency of 10 Mhz at a depth of 10-12 cm. Following insertion of the guidewire into the vein, the probe is shifted to the right supraclavicular fossa to obtain a view of the superior vena cava (SVC), right pulmonary artery and ascending aorta. Under real-time ultrasound view, the guidewire and its J-tip is visualized and pushed forward to the lower SVC. Insertion depth is read from guidewire marks using central venous catheter. CVC is then inserted following skin and venous dilation. The supraclavicular fossa view is most suitable for right IJV CVC insertion. If other insertion sites are chosen the right supraclavicular fossa should be within the sterile field. Scanning of the IJVs, brachiocephalic veins and SVC can reveal significant thrombosis before venipuncture. Misplaced CVCs can be corrected with a change over guidewire technique under real-time ultrasound guidance. In conjunction with a diagnostic lung ultrasound scan, this technique has a potential to replace chest radiograph for confirmation of CVC tip position and exclusion of pneumothorax. Moreover, this view is of advantage in patients with a non-p-wave cardiac rhythm were an intra-cardiac electrocardiography (ECG) is not feasible for CVC tip position confirmation. Limitations of the method are lack of availability of a micro-convex probe and the need for training.

  20. The Hunter pulmonary angiography catheter for a brachiocephalic vein approach. (United States)

    Rosen, Galia; Kowalik, Karen J; Ganguli, Suverano; Hunter, David W


    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a "C-shaped" curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk.

  1. Improved Rare-Earth Emitter Hollow Cathode (United States)

    Goebel, Dan M.


    An improvement has been made to the design of the hollow cathode geometry that was created for the rare-earth electron emitter described in Compact Rare Earth Emitter Hollow Cathode (NPO-44923), NASA Tech Briefs, Vol. 34, No. 3 (March 2010), p. 52. The original interior assembly was made entirely of graphite in order to be compatible with the LaB6 material, which cannot be touched by metals during operation due to boron diffusion causing embrittlement issues in high-temperature refractory materials. Also, the graphite tube was difficult to machine and was subject to vibration-induced fracturing. This innovation replaces the graphite tube with one made out of refractory metal that is relatively easy to manufacture. The cathode support tube is made of molybdenum or molybdenum-rhenium. This material is easily gun-bored to near the tolerances required, and finish machined with steps at each end that capture the orifice plate and the mounting flange. This provides the manufacturability and robustness needed for flight applications, and eliminates the need for expensive e-beam welding used in prior cathodes. The LaB6 insert is protected from direct contact with the refractory metal tube by thin, graphite sleeves in a cup-arrangement around the ends of the insert. The sleeves, insert, and orifice plate are held in place by a ceramic spacer and tungsten spring inserted inside the tube. To heat the cathode, an insulating tube is slipped around the refractory metal hollow tube, which can be made of high-temperature materials like boron nitride or aluminum nitride. A screw-shaped slot, or series of slots, is machined in the outside of the ceramic tube to constrain a refractory metal wire wound inside the slot that is used as the heater. The screw slot can hold a single heater wire that is then connected to the front of the cathode tube by tack-welding to complete the electrical circuit, or it can be a double slot that takes a bifilar wound heater with both leads coming out

  2. Enterobacter aerogenes Needle Stick Leads to Improved Biological Management System

    Energy Technology Data Exchange (ETDEWEB)

    Johanson, Richard E.


    A laboratory worker who received a needle stick from a contaminated needle while working with a culture containing Enterobactor aerogenes developed a laboratory acquired infection. Although this organism has been shown to cause community and nosocomial infections, there have been no documented cases of a laboratory acquired infections. Lessons learned from the event led to corrective actions which included modification of lab procedures, development of a biological inventory tracking and risk identification system and the establishment of an effective biological safety program.

  3. Ultrasound guided needle biopsy of skeletal muscle in neuromuscular disease

    DEFF Research Database (Denmark)

    Lindequist, S; Schrøder, H D; Larsen, C


    Guided by ultrasonography percutaneous needle biopsy of skeletal muscle was performed in 24 patients, using the one hand held Biopty system and a 2 mm Tru-Cut needle. The specimens were graded with regard to diagnostic quality and utility and almost all specimens (96%) were of highest quality....... The use of ultrasonography was helpful in selecting a suitable area for the biopsy and vascular structures could be avoided. The procedure was well tolerated and easy to perform, and no complications were recorded....

  4. Clinical Application of Movement-needling Technique: Stiff Neck

    Institute of Scientific and Technical Information of China (English)

    LIU Yan


    @@ Movement-needling Technique, a new acupuncture therapy, is based on traditional acupuncture therapy and anatomical principle, combining acupuncture and movement. Combining disease and syndrome differentiation, and integrating TCM and Western medical diagnosis, this technique is used to treat different diseases mainly with acupuncture,combining some movement in needling. These movements not only boost therapeutic effects of acupuncture, but also add new contents to traditional acupuncture.

  5. Imaging of the complications of peripherally inserted central venous catheters

    Energy Technology Data Exchange (ETDEWEB)

    Amerasekera, S.S.H. [Department of Radiology, Good Hope Hospital, Sutton Coldfield, Birmingham (United Kingdom)], E-mail:; Jones, C.M.; Patel, R.; Cleasby, M.J. [Department of Radiology, Good Hope Hospital, Sutton Coldfield, Birmingham (United Kingdom)


    Peripherally inserted central catheters (PICC) are widely used to provide central venous access, often in chronically ill patients with long-term intravenous access requirements. There are a number of significant complications related to both insertion and maintenance of PICC lines, including catheter malposition, migration, venous thrombosis, and line fracture. The incidence of these complications is likely to rise as the number of patients undergoing intravenous outpatient therapy increases, with a corresponding rise in radiologist input. This paper provides an overview of the relevant peripheral and central venous anatomy, including anatomical variations, and outlines the complications of PICC lines. Imaging examples demonstrate the range of radiological findings seen in these complications.

  6. Imaging of the complications of peripherally inserted central venous catheters. (United States)

    Amerasekera, S S H; Jones, C M; Patel, R; Cleasby, M J


    Peripherally inserted central catheters (PICC) are widely used to provide central venous access, often in chronically ill patients with long-term intravenous access requirements. There are a number of significant complications related to both insertion and maintenance of PICC lines, including catheter malposition, migration, venous thrombosis, and line fracture. The incidence of these complications is likely to rise as the number of patients undergoing intravenous outpatient therapy increases, with a corresponding rise in radiologist input. This paper provides an overview of the relevant peripheral and central venous anatomy, including anatomical variations, and outlines the complications of PICC lines. Imaging examples demonstrate the range of radiological findings seen in these complications.

  7. Sagittal vein thrombosis caused by central vein catheter.

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi


    Full Text Available Cerebral venous thrombosis, including thrombosis of cerebral veins and major dural sinuses, is an uncommon disorder in the general population. However, it has a higher frequency among patients younger than 40 years of age, patients with thrombophilia, pregnant patients or those receiving hormonal contraceptive therapy or has foreign body such as catheter in their veins or arterial system. In this case report, we described clinical and radiological findings in a patient with protein C-S deficiency and malposition of central vein catheter.

  8. Spontaneous migration of central venous catheter tip following extubation

    Directory of Open Access Journals (Sweden)

    Balaji Prabaharan


    Full Text Available Migration of the tip of central venous catheters is not an uncommon event and the mechanism for this is not clear. Increased intrathoracic pressure due to coughing, sneezing or weight lifting, changing the body position or physical movements such as abduction or adduction of the arms is thought to be the cause of such migration. We present here a case of a patient with a port catheter tip that migrated from the left subclavian to the superior vene cava following extubation.

  9. The catheter hub disinfection cap as esophageal foreign body. (United States)

    Tawfik, Kareem O; Myer, Charles M; Shikary, Tasneem; Goldschneider, Kenneth R


    Disinfection caps are increasingly being used to prevent catheter-associated bloodstream infections. These devices, designed for continuous passive disinfection of catheter hubs, are typically small and often brightly colored. As such, they have the potential to become pediatric airway and esophageal foreign bodies. We report two patients who developed esophageal foreign body following ingestion of disinfection caps. Given the increasing use of these devices, it is imperative that health care providers be aware of this potential iatrogenic problem. We propose that the use of disinfection caps may not be appropriate in pediatric patients with risk factors for foreign body ingestion.

  10. Formation of hollow nanocrystals through the nanoscale kirkendall effect

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yadong; Rioux, Robert M.; Erdonmez, Can K.; Hughes, Steven; Somorjai, Gabor A.; Alivisatos, A. Paul


    We demonstrate that hollow nanocrystals can be synthesized through a mechanism analogous to the Kirkendall Effect, in which pores form due to the difference in diffusion rates between two components in a diffusion couple. Cobalt nanocrystals are chosen as a primary example to show that their reaction in solution with oxygen, sulfur or selenium leads to the formation of hollow nanocrystals of the resulting oxide and chalcogenides. This process provides a general route to the synthesis of hollow nanostructures of large numbers of compounds. A simple extension of this process yields platinum-cobalt oxide yolk-shell nanostructures which may serve as nanoscale reactors in catalytic applications.


    Institute of Scientific and Technical Information of China (English)


    A novel method to prepare crosslinked polyethyleneimine (CPEI) hollow nanospheres was reported.Uniform silica nanospheres were used as templates,3-aminopropyl trimethoxysilane (APS) was immobilized on the surface of silica nanospheres as couple agent.Aziridine was initiated ring-opening polymerization with the amino groups in APS to form polyethyleneimine (PEI) shell layer.1,4-Butanediol diacrylate was utilized to crosslink PEI polymeric shell.The silica nanospheres in core were etched by hydrofluoric acid to obtain hollow CPEI nanospheres.The hollow nanospheres were characterized by X-ray photoelectron spectroscopy (XPS),transmission electron microscopy (TEM),and thermogravimetric analysis (TGA).

  12. The Romantic Prototype of The Legend of Sleepy Hollow

    Institute of Scientific and Technical Information of China (English)

    冯育军; 王艳


    "The Legend of Sleepy Hollow" is a short story of speculative fiction by American author Washington Irving, con-tained in his collection of 34 essays and short stories entitled The Sketch Book of Geoffrey Crayon, Gent. Written while Irving was living abroad in Birmingham, England,"The Legend of Sleepy Hollow"was first published in 1820. Along with Irving's com-panion piece"Rip Van Winkle","The Legend of Sleepy Hollow"is among the earliest examples of American fiction with endur-ing popularity, especially during the Halloween season.

  13. Hollow Gaussian Schell-model beam and its propagation

    CERN Document Server

    Wang, Li-Gang


    In this paper, we present a new model, hollow Gaussian-Schell model beams (HGSMBs), to describe the practical dark hollow beams. An analytical propagation formula for HGSMBs passing through a paraxial first-order optical system is derived based on the theory of coherence. Based on the derived formula, an application example showing the influence of spatial coherence on the propagation of beams is illustrated. It is found that the beam propagating properties of HGSMBs will be greatly affected by their spatial coherence. Our model provides a very convenient way for analyzing the propagation properties of partially coherent dark hollow beams.

  14. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; Assmann, R.; Kabantsev, A.


    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams

  15. Hollow Electron Beam Collimator: R&D Status Report

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Valishev, A; Kabantsev, A; Vorobiev, L


    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  16. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Still, D A; Valishev, A; Vorobiev, L G; Assmann, R; Kabantsev, A


    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  17. Hollow infrared fibers fabricated by glass-drawing technique. (United States)

    Matsuura, Yuji; Kasahara, Ryosuke; Katagiri, Takashi; Miyagi, Mitsunobu


    Hollow glass fibers for delivery of mid-infrared lasers are drawn from a glass-tube preform to produce a long and flexible hollow fiber at low cost. To utilize the interference effect of the thin glass wall, the wall thickness is controlled by the drawing speed. A Pyrex-glass hollow fiber with an inner diameter of 280 microm and a wall thickness of 9.92 microm shows a low loss at 2.94 microm of the Er:YAG laser wavelength when coated with a silver film on the outer surface.

  18. New cobweb-structure hollow Bragg optical fibers

    Institute of Scientific and Technical Information of China (English)

    YU Rong-jin; ZHANG Yong-qiang; ZHANG Bing; WANG Chao-ran; WU Chang-qi


    A new type of Bragg fibers,i.e. hollow-core cobweb-structured optical fibers,which can be used to the low-loss transmission from visible to near infrared region (0.65 μm-1.55 μm),terahertz wave (200 μm-480 μm) and circular-polarization-maintaining single-mode transmission are investigated. Results show that the hollow-core cobweb-structured fibers have less loss than other hollow-core Bragg fibers. The fibers can be constituted by using the plastics or glasses with large absorption losses.

  19. Axisymmetric Vibration of Piezo-Lemv Composite Hollow Multilayer Cylinder

    Directory of Open Access Journals (Sweden)

    E. S. Nehru


    Full Text Available Axisymmetric vibration of an infinite piezolaminated multilayer hollow cylinder made of piezoelectric layers of 6 mm class and an isotropic LEMV (Linear Elastic Materials with Voids layers is studied. The frequency equations are obtained for the traction free outer surface with continuity conditions at the interfaces. Numerical results are carried out for the inner, middle, and outer hollow piezoelectric layers bonded by LEMV (It is hypothetical material layers and the dispersion curves are compared with that of a similar 3-layer model and of 3 and 5 layer models with inner, middle, and outer hollow piezoelectric layers bonded by CFRP (Carbon fiber reinforced plastics.

  20. Validation of the Accuracy and Reliability of Culturing Intravascular Catheter Segments (United States)


    catheters over guidewire using the Seldinger technique , bedside plating of catheter segments and preparation of segments for transport to the...physician(s) responsible for the patient’s care, using strict aseptic technique . Sterile 2 gowns and gloves, sterile barriers and caps were required...CULTURES Catheter subsegments sent to the lab were cultured using semiquantitative technique described by Maki. 1 The catheter subsegments were

  1. Analysis on enzymatic browning in pine needles

    Energy Technology Data Exchange (ETDEWEB)

    Kong, K.H.; Park, H.J.; Choi, S.S.; Cho, S.H. [Chung-Ang University, Seoul (Korea); Kim, Y.T. [Aoyama Gakuin University, Tokyo (Japan)


    Tyrosinases are related to the enzymatic browning of plants and attract the major scientific interest for the prevention of it. Three tyrosinase isozymes (P{sub 1}, P{sub 2} and P{sub 3}) from pine needles were purified to homogeneity and characterized the factors that affect their activities. The L-ascorbic acid and {beta}-mercaptoethanol notably inhibited the enzymatic activities of the three isozymes. The sodium diethyldithiocarbamate was a competitive inhibitor of isozymes with the K{sub i} values of P{sub 1}(0.30 mM), P{sub 2}(0.015 mM) and P{sub 3}(0.019 mM), respectively. Their enzyme activities were however, increased by the addition of most metal ions. The optimum pH for the three isozymes was 9.0{approx}9.5 and the optimum temperatures ranged from 55 to 60{sup o} C using L-DOPA as substrate. 15 refs., 3 figs., 2 tabs.

  2. Fine needle aspiration cytology of dermal cylindroma

    Directory of Open Access Journals (Sweden)

    Parikshaa Gupta


    Full Text Available In this paper, we have described fine needle aspiration cytology (FNAC of a rare case of dermal cylindroma. A 40-year-old female presented with a lateral mid-cervical swelling fixed to the skin. FNAC smears showed multiple clusters of small, round to oval cells with hyperchromatic nuclei, inconspicuous nucleoli and scant cytoplasm. In addition, the background showed deposits of basement membrane type material. This was dark magenta colored pinkish globular material. The globules were occasionally surrounded by the basal type of cells. Occasional cells with elongated nuclei were also noted. Cytological diagnosis of skin adnexal tumor possibly cylindroma was offered. Subsequent histopathology of the swelling showed sheets and clusters of cells in a jigsaw puzzle-like fashion. Deposition of abundant basement membrane-like material was noted in between the tumor cells. A diagnosis of cylindorma was offered. FNAC along with the subcutaneous location of the tumor and absence of primary salivary gland tumor may help to diagnose such rare case.

  3. Percutaneous transhepatic cholangiography using fine needle

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyoo Byung; Kim, Yun Hwan; Lee, Nam Joon; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of)


    In recent years, percutaneous transhepatic cholangiography (PTC) using fine needle has become widely employed as the procedure of choice for direct opacification of the biliary trees because of its high success rate, easy performance and relative low complication rate. Authors present the clinical and PTC findings of experienced cases during last four years, from May 1976 to June 1980, at the Department of Radiology, Korea University Hospital. We tried to study of PTC in 44 cases, 32 males and 12 females, and succeeded in visualization of bile ducts in 41 cases, but the other three cases were failed to visualize the bile ducts. Final confirmative diagnosis was achieved in 29 cases by operation, laparoscopy and other clinical methods. The PTC diagnosis was correct in 24 of 29 cases, and the others were incorrect. The 29 final diagnosis was including 13 cases of biliary stones, 6 cases of biliary cancer, 3 cases of pancreatic cancer, 3 cases of clonorchiasis, one case of CBD ascariasis and 3 cases of others. Incorrect PTC diagnosis was made in five cases. They were one case of nonvisualized intrahepatic stones, one case of hepatoma PTC diagnosed as cholangiocarcinoma, one case of pancreatic cancer diagnosed as cholangiocarcinoma, one case of clonorchiasis diagnosed as biliary stones and one case of normal CBD which was diagnosed as distal CBD cancer. And we experienced one case of bile peritonitis as complication, who was 35 year-old female patient with multiple CBD stones, and aspirated about 500ml of bile stained ascites during operation.

  4. Fine needle aspiration cytology in leprosy

    Directory of Open Access Journals (Sweden)

    Prasad PVS


    Full Text Available Background: Laboratory diagnosis of leprosy by slit skin smear and skin biopsy is simple but both techniques have their own limitations. Slit skin smear is negative in paucibacillary cases whereas skin biopsy is an invasive technique. Fine needle aspiration cytology (FNAC from skin lesions in leprosy with subsequent staining with May-Grunwald-Giemsa (MGG stain has been found useful. Aim: To evaluate the possible role of cytology in classifying leprosy patients. Methods: Seventy-five untreated cases of leprosy attending the outpatient department were evaluated. Smears were taken from their skin lesions and stained using the MGG technique. Skin biopsy was also done from the lesions, which was compared with cytology smears. Results: A correlation of clinical features with FNAC was noticed in 87.5% of TT, 92.1% of BT, 81% of BL, and 66% of LL cases. Correlation of clinical with histopathological diagnoses revealed 12.5% specificity in TT leprosy, 55.3% in BT, 52.4% in BL and 50% in LL, and 100% in neuritic and histoid leprosy cases. Both correlations were found to be statistically significant by paired t test analysis. Thus, it was possible to distinguish the tuberculoid types by the presence of epithelioid cells and the lepromatous types by the presence of lymphocytes and foamy macrophages. Conclusion: FNAC may be used to categorize the patients into paucibacillary and multibacillary types, but is not a very sensitive tool to classify the patients across the Ridley-Jopling spectrum.

  5. Needle core biopsy for breast lesions: An audit of 467 needle core biopsies

    Directory of Open Access Journals (Sweden)

    Selvi Radhakrishna


    Full Text Available Background: Breast cancer is the commonest cancer among women in urban India. Triple assessment includes clinical, radiological and cytological assessment of breast lesions. Guided core needle biopsy has replaced fine needle aspiration cytology in most of the western countries. In resource poor countries FNAC is still a very valuable and cost effective method to diagnose breast lesions. Pitfalls include increased rates of non diagnostic smears, and inadequate smears. Further procedures may be required and this increases the cost, anxiety and delay in diagnosis. Aims: The aim of this study is to analyze the concordance of radiological and histopathology findings in BI-RADS category 3,4,5 lesions following a core biopsy. Materials and Methods: Data was retrospectively collected from consecutive symptomatic and opportunistic screen detected patients with abnormalities who underwent ultrasound guided interventional procedures from Jan 2010 to Aug 2011. Symptomatic patients underwent clinical examination, mammogram and breast ultrasound. Women under 35 years of age had only breast ultrasound. Core biopsy was performed under ultrasound guidance or clinically by a breast surgeon/ radiologist for BI-RADS category 3,4,5 lesions. Statistical Methods: Chi square test was done to show the strength of association of imaging findings and histopathology results of core biopsy. Results: 437 patients were symptomatic and 30 patients had screen detected abnormalities. The positive predictive value for BI-RADS 5 lesions for malignancy is 93.25% and the negative predictive value of BI-RADS category 3 lesions for cancer is 98.4%. False negative diagnosis on core biopsy was 0.85%. We were able to defer surgery in 60% of the patients with a clear radiological and pathological benign diagnosis. Conclusion: The PPV and NPV for cancer is high with needle core biopsy in BI-RADS 3,4,5 lesions. Where there is no discordance between clinical, radiology and pathology findings

  6. Neuromuscular Damage and Repair after Dry Needling in Mice

    Directory of Open Access Journals (Sweden)

    Ares Domingo


    Full Text Available Objective. Some dry needling treatments involve repetitive and rapid needle insertions into myofascial trigger points. This type of treatment causes muscle injury and can also damage nerve fibers. The aim of this study is to determine the injury caused by 15 repetitive punctures in the muscle and the intramuscular nerves in healthy mouse muscle and its ulterior regeneration. Methods. We repeatedly needled the levator auris longus muscle of mice, and then the muscles were processed with immunohistochemistry, methylene blue, and electron microscopy techniques. Results. Three hours after the dry needling procedure, the muscle fibers showed some signs of an inflammatory response, which progressed to greater intensity 24 hours after the procedure. Some inflammatory cells could still be seen when the muscle regeneration was almost complete seven days after the treatment. One day after the treatment, some changes in the distribution of receptors could be observed in the denervated postsynaptic component. Reinnervation was complete by the third day after the dry needling procedure. We also saw very fine axonal branches reinnervating all the postsynaptic components and some residual sprouts the same day. Conclusion. Repeated dry needling punctures in muscle do not perturb the different stages of muscle regeneration and reinnervation.

  7. Mechanics of dynamic needle insertion into a biological material. (United States)

    Mahvash, Mohsen; Dupont, Pierre E


    During needle-based procedures, transitions between tissue layers often lead to rupture events that involve large forces and tissue deformations and produce uncontrollable crack extensions. In this paper, the mechanics of these rupture events is described, and the effect of insertion velocity on needle force, tissue deformation, and needle work is analyzed. Using the J integral method from fracture mechanics, rupture events are modeled as sudden crack extensions that occur when the release rate J of strain energy concentrated at the tip of the crack exceeds the fracture toughness of the material. It is shown that increasing the velocity of needle insertion will reduce the force of the rupture event when it increases the energy release rate. A nonlinear viscoelastic Kelvin model is then used to predict the relationship between the deformation of tissue and the rupture force at different velocities. The model predicts that rupture deformation and work asymptotically approach minimum values as needle velocity increases. Consequently, most of the benefit of using a higher needle velocity can be achieved using a finite velocity that is inversely proportional to the relaxation time of the tissue. Experiments confirm the analytical predictions with multilayered porcine cardiac tissue.

  8. Nursing and safety of silver needle diathermy treating ankylosing spondylitis. (United States)

    Ning, Huaxiu; Wang, Yun; Yuan, Yiwen; Ning, Huaying


    This paper aims to discuss the nursing and safety of silver needle diathermy in the treatment for ankylosing spondylitis. We nursed 46 patients with ankylosing spondylitis treated with silver needle diathermy. Specific nursing was focused on physical condition evaluation and mental nursing before treatment, observation during and after treatment, diet nursing, needle eye nursing, functional training and propaganda and education when discharged. The result suggested that all the patients received mental nursing, diet guide, skin care, health education, functional training and follow-up visit from the nurse and all of them could endure silver needle diathermy as discomfort or drug allergy was barely found, so were slight scald and skin infection nearby the needle eye caused by fainting during acupuncture, accidental puncture or overheat. Follow-up visit showed that no patient suffered obvious untoward effect and the pain, joint range of motion and living condition were distinctly improved a week after discharging. In conclusion, during the treatment for ankylosing spondylitis applying silver needle diathermy, the nursing before, during and after the treatment can obviously reduce the complication, accelerate the recovery, which is highly safe.

  9. Antioxidant, antimutagenic, and antitumor effects of pine needles (Pinus densiflora). (United States)

    Kwak, Chung Shil; Moon, Sung Chae; Lee, Mee Sook


    Pine needles (Pinus densiflora Siebold et Zuccarini) have long been used as a traditional health-promoting medicinal food in Korea. To investigate their potential anticancer effects, antioxidant, antimutagenic, and antitumor activities were assessed in vitro and/or in vivo. Pine needle ethanol extract (PNE) significantly inhibited Fe(2+)-induced lipid peroxidation and scavenged 1,1-diphenyl- 2-picrylhydrazyl radical in vitro. PNE markedly inhibited mutagenicity of 2-anthramine, 2-nitrofluorene, or sodium azide in Salmonella typhimurium TA98 or TA100 in Ames tests. PNE exposure effectively inhibited the growth of cancer cells (MCF-7, SNU-638, and HL-60) compared with normal cell (HDF) in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In in vivo antitumor studies, freeze-dried pine needle powder supplemented (5%, wt/wt) diet was fed to mice inoculated with Sarcoma-180 cells or rats treated with mammary carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA, 50 mg/kg body weight). Tumorigenesis was suppressed by pine needle supplementation in the two model systems. Moreover, blood urea nitrogen and aspartate aminotransferase levels were significantly lower in pine needle-supplemented rats in the DMBA-induced mammary tumor model. These results demonstrate that pine needles exhibit strong antioxidant, antimutagenic, and antiproliferative effects on cancer cells and also antitumor effects in vivo and point to their potential usefulness in cancer prevention.

  10. Initial experience with new dedicated needles for laparoscopic ultrasound-guided fine-needle aspiration and histological biopsies

    DEFF Research Database (Denmark)

    Mortensen, M B; Durup, J; Pless, T;


    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....... Primary diagnosis, duration of biopsy procedure, needle monitoring (visibility, penetration, and deviation), complications, technical failures, and pathological findings were prospectively recorded. RESULTS: 44 biopsies were performed with 25 needles (19, 20, and 22-G). Needle monitoring and penetration...

  11. Molecular motor transport through hollow nanowires

    DEFF Research Database (Denmark)

    Lard, Mercy; Ten Siethoff, Lasse; Generosi, Johanna;


    Biomolecular motors offer self-propelled, directed transport in designed microscale networks and can potentially replace pump-driven nanofluidics. However, in existing systems, transportation is limited to the two-dimensional plane. Here we demonstrate fully one-dimensional (1D) myosin-driven mot......Biomolecular motors offer self-propelled, directed transport in designed microscale networks and can potentially replace pump-driven nanofluidics. However, in existing systems, transportation is limited to the two-dimensional plane. Here we demonstrate fully one-dimensional (1D) myosin......-driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O 3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays...

  12. Nonparaxial Dark-Hollow Gaussian Beams

    Institute of Scientific and Technical Information of China (English)

    GAO Zeng-Hui; L(U) Bai-Da


    The concept of nonparaxial dark-hollow Gaussian beams (DHGBs) is introduced. By using the Rayleigh-Sommerfeld diffraction integral, the analytical propagation equation of DHGBs in free space is derived. The on-axis intensity, far-field equation and, in particular, paraxial expressions are given and treated as special cases of our result. It is shown that the parameter f = 1/kw0 with k being the wave number and w0 being the waist width determines the nonparaxiality of DHGBs. However, the parameter range, within which the paraxial approach is valid, depends on the propagation distance. The beam order affects the beam profile and position of maximum on-axis intensity.

  13. Permeability of Hollow Microspherical Membranes to Helium (United States)

    Zinoviev, V. N.; Kazanin, I. V.; Pak, A. Yu.; Vereshchagin, A. S.; Lebiga, V. A.; Fomin, V. M.


    This work is devoted to the study of the sorption characteristics of various hollow microspherical membranes to reveal particles most suitable for application in the membrane-sorption technologies of helium extraction from a natural gas. The permeability of the investigated sorbents to helium and their impermeability to air and methane are shown experimentally. The sorption-desorption dependences of the studied sorbents have been obtained, from which the parameters of their specific permeability to helium are calculated. It has been established that the physicochemical modification of the original particles exerts a great influence on the coefficient of the permeability of a sorbent to helium. Specially treated cenospheres have displayed high efficiency as membranes for selective extraction of helium.

  14. Chalcogenide glass hollow core photonic crystal fibers (United States)

    Désévédavy, Frédéric; Renversez, Gilles; Troles, Johann; Houizot, Patrick; Brilland, Laurent; Vasilief, Ion; Coulombier, Quentin; Traynor, Nicholas; Smektala, Frédéric; Adam, Jean-Luc


    We report the first hollow core photonic crystal fibers (HC PCF) in chalcogenide glass. To design the required HC PCF profiles for such high index glass, we use both band diagram analysis to define the required photonic bandgap and numerical simulations of finite size HC PCFs to compute the guiding losses. The material losses have also been taken into account to compute the overall losses of the HC PCF profiles. These fibers were fabricated by the stack and draw technique from TeAsSe (TAS) glass. The fibers we drew in this work are composed of six rings of holes and regular microstructures. Two profiles are presented, one is known as a kagome lattice and the other one corresponds to a triangular lattice. Geometrical parameters are compared to the expected parameters obtained by computation. Applications of such fibers include power delivery or fiber sensors among others.

  15. Two-piece hollow bulb obturator

    Directory of Open Access Journals (Sweden)

    Subramaniam Elangovan


    Full Text Available There are various types of obturator fabrication achievable by prosthodontist. Maxillectomy, which is a term used by head and neck surgeons and prosthodontists to describe the partial or total removal of the maxilla in patients suffering from benign or malignant neoplasms is a defect for which to provide an effective obturator is a difficult task for the maxillofacial prosthodontist. Multidisciplinary treatment planning is essential to achieve adequate retention and function for the prosthesis. Speech is often unintelligible as a result of the marked defects in articulation and nasal resonance. This paper describes how to achieve the goal for esthetics and phonetics and also describes the fabrication of a hollow obturator by two piece method, which is simple and maybe used as definitive obturator for maximum comfort of the patient.

  16. Dual-core antiresonant hollow core fibers. (United States)

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing


    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  17. Housing shortages in urban regions: aggressive interactions at tree hollows in forest remnants. (United States)

    Davis, Adrian; Major, Richard E; Taylor, Charlotte E


    Urbanisation typically results in a reduction of hollow-bearing trees and an increase in the density of particularly species, potentially resulting in an increased level of competition as cavity-nesting species compete for a limited resource. To improve understanding of hollow usage between urban cavity-nesting species in Australia, particularly parrots, we investigated how the hollow-using assemblage, visitation rate, diversity and number of interactions varied between hollows within urban remnant forest and continuous forest. Motion-activated video cameras were installed, via roped access to the canopy, and hollow usage was monitored at 61 hollows over a two-year period. Tree hollows within urban remnants had a significantly different assemblage of visitors to those in continuous forest as well as a higher rate of visitation than hollows within continuous forest, with the rainbow lorikeet making significantly more visitations than any other taxa. Hollows within urban remnants were characterised by significantly higher usage rates and significantly more aggressive interactions than hollows within continuous forest, with parrots responsible for almost all interactions. Within urban remnants, high rates of hollow visitation and both interspecific and intraspecific interactions observed at tree hollows suggest the number of available optimal hollows may be limiting. Understanding the usage of urban remnant hollows by wildlife, as well as the role of parrots as a potential flagship for the conservation of tree-hollows, is vital to prevent a decrease in the diversity of urban fauna, particularly as other less competitive species risk being outcompeted by abundant native species.

  18. Central venous catheter-related infections: Risk factors and effects of glycopeptide antibiotics

    Directory of Open Access Journals (Sweden)

    Arsenijević Ljubica


    Full Text Available INTRODUCTION Central venous catheters (CVC are used in the treatment of critically ill patients. Indications for placement of CVCs include hemodynamic monitoring, administration of intravenous fluids, medications and total parenteral nutrition. MATERIAL AND METHODS We investigated risk factors and effects of glycopeptide antibiotics on the development of central venous catheter-related infections in 300 patients treated in intensive care units. A semiquntitative culture technique was used. The investigation included: age, diagnosis on admission, catheter insertion site, catheter duration, the first or next catheter and using of glycopeptide drugs. RESULTS 91 catheters (30.3% were colonised, catheter-related infection was found in 50 catheters (16.7%. Infections were more frequent in catheters inserted through the internal jugular vein than in subclavian venous catheters; they were also more frequent if duration of catheterization was longer than seven days, but less frequent in patients who received glycopeptide antibiotics. The isolated microorganism was Staphylococcus aureus. DISCUSSION According to the literature, a number of catheter-related risk factors for infections include: insertion site, type of catheter, the number of manipulations, inadequat asepsis, lumen number, type of antiseptic. The relative importance of one risk factor over another is difficult to assess, given that studies have no priority report. CONCLUSION The duration of catheterization and the insertion site were the most frequent risk factors for infection. The use of glycopeptide antibiotics during catheterization has protective effects.

  19. Placing of tunneled central venous catheters prior to induction chemotherapy in children with acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Møller, Jens Kjølseth; Frydenberg, Morten


    BACKGROUND: Tunneled central venous catheters (CVCs) are inevitable in children with acute lymphoid leukemia (ALL). The aim of this study was to evaluate the risk of CVC-related complications in children with ALL in relation to timing of catheter placement and type of catheter. PROCEDURE: All chi...

  20. Percutaneous transvenous retrieval of CVP catheter emboli in S. V. C.-A case report-

    Energy Technology Data Exchange (ETDEWEB)

    Zeon, Seok Kil; Lee, Deock Hee; Kim, Hong; Kim, Ok Bae [Keimyung University College of Medicine, Taegu (Korea, Republic of)


    The increasing use of the indwelling venous catheters and cardiovascular catheters has led to many iatrogenic complications. One of the most serious complications is catheter embolization, caused by inadvertent fracture of a fragment of catheter remaining within cardiovascular systems. In the catheter embolization, there are serious consequence such as thromboembolism, sepsis, cardiac arrhythmia and others. Fisher and Ferreyro (1978) reported a 71% incidence of serious morbidity or death following to intravascular foreign bodies in patients without removal. The authors experienced a case of retained central venous pressure monitoring catheter (CVP catheter) fragment extending from superior vena cava to hepatic segment of inferior vena cava. CVP catheter wa introduced into right subclavian venous route for hyperalimentation, because of poor general condition for operation of afferent loop syndrome following to resection of the gastric carcinoma with Billoth II operation (5 years age). On attempting removal of CVP catheter on recovery from afferent loop syndrome, a large portion of the CVP catheter was cut off in S.V.C. Percutaneous puncture of right femoral vein with Seldinger technique was done and 9F introducer sheath was indwelled. The helical basket of Dotter intravascular retriever set was advance through the sheath up to retained CVP catheter, and it was grasped. The retrieved CVP catheter fragment showed several tiny blood clots on surface. The patient was uneventfully recovered and was discharged asymptomatic on second day of the procedure.