WorldWideScience

Sample records for 45-mhz needle transducer

  1. Novice performance of ultrasound-guided needle advancement: standard 38-mm transducer vs 25-mm hockey stick transducer.

    Science.gov (United States)

    Davies, T; Townsley, P; Jlala, H; Dowling, M; Bedforth, N; Hardman, J G; McCahon, R A

    2012-08-01

    The optimal method to develop expertise in ultrasound-guided regional anaesthesia is unknown. Studies of laryngoscopic expertise in novices demonstrate that the choice of laryngoscope affects performance. In this study, we aimed to compare the effect of two different linear array transducers (38-mm standard vs 25-mm hockey stick) on novice performance of ultrasound-guided needle advancement. Following randomisation, participants watched a video model of expert performance of ultrasound-guided needle advancement. Recruits performed the modelled task on a turkey breast model. The median (IQR [range]) composite error score was statistically significantly larger for participants in the hockey stick transducer group compared with the standard transducer group; 10.0 (7.3-14.3 [2.5-29.0]) vs 7.5 (4.5-10.0 [2.0-28.0]) respectively, (p = 0.01). This study has demonstrated that performance of ultrasound-guided needle advancement by novice operators after simple video instruction is better (as assessed using a composite error score) with a standard 38-mm transducer than with a 25-mm hockey stick transducer. PMID:22506607

  2. Dual Orientation 16-MHz Single-Element Ultrasound Needle Transducers for Image-Guided Neurosurgical Intervention.

    Science.gov (United States)

    Jiang, Yun; Qiu, Zhen; McPhillips, Rachael; Meggs, Carl; Mahboob, Syed Osama; Wang, Han; Duncan, Robyn; Rodriguez-Sanmartin, Daniel; Zhang, Ye; Schiavone, Giuseppe; Eisma, Roos; Desmulliez, Marc P Y; Eljamel, Sam; Cochran, Sandy; Button, Tim W; Demore, Christine E M

    2016-02-01

    Image-guided surgery is today considered to be of significant importance in neurosurgical applications. However, one of its major shortcomings is its reliance on preoperative image data, which does not account for brain deformations and displacements that occur during surgery. In this work, we propose to tackle this issue through the incorporation of an ultrasound device within the type of biopsy needles commonly used as an interventional tool to provide immediate feedback to neurosurgeons during surgical procedures. To identify the most appropriate path to access a targeted tissue site, single-element transducers that look either forward or sideways have been designed and fabricated. Micromolded 1-3 piezocomposites were adopted as the active materials for feasibility tests and epoxy lenses have been applied to focus the ultrasound beam. Electrical impedance analysis, pulse-echo testing, and wire phantom scanning have been carried out, demonstrating the functionality of the needle transducers at [Formula: see text]. The capabilities of these transducers for intraoperative image guidance were demonstrated by imaging within soft-embalmed cadaveric human brain and fresh porcine brain. PMID:26672034

  3. Measurements of attenuation coefficient for evaluating the hardness of a cataract lens by a high-frequency ultrasonic needle transducer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.-C. [Department of Electronic Engineering, Fu Jen Catholic University, Taipei 24205, Taiwan (China); Chen Ruimin; Zhou Qifa; Shung, K Kirk [NIH Resource on Medical Ultrasonic Transducer Technology, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089 (United States); Tsui, P.-H. [Division of Mechanics, Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan (China); Humayun, Mark S [Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)], E-mail: j648816n@ms23.hinet.net

    2009-10-07

    A cataract is a clouding of the lens in the eye that affects vision. Phacoemulsification is the mostly common surgical method for treating cataracts, and determining that the optimal phacoemulsification energy is dependent on measuring the hardness of the lens. This study explored the use of an ultrasound needle transducer for invasive measurements of ultrasound attenuation coefficient to evaluate the hardness of the cataract lens. A 47 MHz high-frequency needle transducer with a diameter of 0.9 mm was fabricated by a polarized PMN-33%PT single crystal in the present study. The attenuation coefficients at different stages of an artificial porcine cataract lens were measured using the spectral shift approach. The hardness of the cataract lens was also evaluated by mechanical measurement of its elastic properties. The results demonstrated that the ultrasonic attenuation coefficient was increased from 0.048 {+-} 0.02 to 0.520 {+-} 0.06 dB mm{sup -1} MHz{sup -1} corresponding to an increase in Young's modulus from 6 {+-} 0.4 to 96 {+-} 6.2 kPa as the cataract further developed. In order to evaluate the feasibility of combining needle transducer and phacoemulsification probe for real-time measurement during cataract surgery, the needle transducer was mounted on the phacoemulsification probe for a vibration test. The results indicated that there was no apparent damage to the tip of the needle transducer and the pulse-echo test showed that a good performance in sensitivity was maintained after the vibration test.

  4. Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

    Directory of Open Access Journals (Sweden)

    Tae-Hoon Bok

    2014-09-01

    Full Text Available The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ~ 330° and at a distance range of 6 ~ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ~ 220° and at a distance range of 7.5 ~ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

  5. A partial 45 MHz sky temperature map obtained from the observations of five ST radars

    Directory of Open Access Journals (Sweden)

    B. Campistron

    Full Text Available A sky temperature map at 45 MHz covering declination between + 30° and + 60°  is presented. The sampling in right ascension is 20 min (~5° and 2°  in declination in most of the map. The originality of the work was to use cosmic emission measurements from five VHF Stratosphere-Troposphere (ST radars collected during long periods of routine meteorological surveys. This map, which has an accuracy in temperature of about 600 K, is intended first for radar reflectivity calibration and system performance monitoring. The presence of two strong radio sources, Cassiopeia A and Cygnus A, can also serve as the verification of the beam diagram, beam width, and beam pointing direction of the antenna. Finally, this work is an attempt to show the potentiality of ST radar for astronomical purposes.

    Key words. Meteorology and atmospheric dynamics (instruments and techniques – Radio science (radio astronomy

  6. Ultrasonic transducer

    International Nuclear Information System (INIS)

    A description is given of an ultrasonic transducer capable of operating at high temperature and comprising a transducer crystal and a coupling piece. This coupling piece is composed of several thin plates, generally triangular in shape, in a material withstanding corrosion and high temperatures, these plates being applied one against the other by pressure. One of the edges of the coupling piece is designed so as to direct towards the junction surfaces of the various plates the ultrasonic waves reflected from the junction between the coupling piece and the piece to which the ultrasonic waves must be transmitted

  7. Ultrasonic transducer

    International Nuclear Information System (INIS)

    An ultrasonic transducer suitable for use up to a temperature of about 6000C comprises a stainless steel casing containing a lithium niobate piezoelectric element and a backing material of a powder which provides a partial pressure of oxygen and thereby prevents deterioration of the element by oxygen loss or contamination. The powder might be of lithium niobate or magnesia. (author)

  8. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...

  9. A flexible piezoelectric transducer design for efficient generation and reception of ultrasonic Lamb waves.

    Science.gov (United States)

    Gachagan, Anthony; Hayward, Gordon; Banks, Robert

    2005-07-01

    This paper describes the development of a flexible piezoelectric transducer for the generation and detection of ultrasonic symmetrical Lamb waves in plate-like structures. This piezoplatelet transducer structure comprises an array of miniature piezoceramic plates embedded within a soft setting polymer filler material, combining the efficiency of the active piezoceramic phase with a degree of flexibility, which is a function of the platelet/polymer dimensions. For many condition-monitoring applications, the generation of ultrasonic Lamb waves is often appropriate, and this was achieved by incorporating interdigital design techniques via the transducer electrode pattern. The performance of the piezoplatelet transducer structure was evaluated using a combination of linear systems and finite-element modeling, substantiated by experimental results. Importantly, the transducer is shown to operate as an ensemble of platelets, each operating in the thickness mode and well decoupled from neighboring piezoelectric elements. Using this transducer configuration, an unimodal s1 Lamb wave, at 1.45 MHz, has been generated and detected in a 3-mm thick steel plate. Furthermore, a propagation distance of almost 1 m was recorded for s0 Lamb wave generation/detection in a fiber-reinforced composite plate. PMID:16212257

  10. Needle autopsy

    Directory of Open Access Journals (Sweden)

    Philip Davis Marsden

    1997-04-01

    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.

  11. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  12. Crossflow force transducer

    International Nuclear Information System (INIS)

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

  13. Modeling of ultrasound transducers

    DEFF Research Database (Denmark)

    Bæk, David

    This Ph.D. dissertation addresses ultrasound transducer modeling for medical ultrasound imaging and combines the modeling with the ultrasound simulation program Field II. The project firstly presents two new models for spatial impulse responses (SIR)s to a rectangular elevation focused transducer...

  14. Needle Biopsy of the Lung

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Needle Biopsy of the Lung Needle biopsy of the lung ... Needle Biopsy of Lung Nodules? What is Needle Biopsy of the Lung? A lung nodule is relatively ...

  15. Pressure Transducer Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — Files are located here, defining the locations of the pressure transducers on the HIRENASD model. These locations also correspond to the locations that analysts...

  16. Improved transvenous liver biopsy needle

    DEFF Research Database (Denmark)

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

    1979-01-01

    A modified type of the standard transvenous cholangiography biopsy needle is described. The modified tranvenous liver biopsy needle caused only minimal artefactual changes of the liver biopsy specimens. The new type of biopsy needle is a modified Menghini needle. The conventional Menghini needle...... should be avoided for transvenous catheter biopsies because of risk of leaving catheter fragments in the liver....

  17. Circular PVDF Airborne Transducer

    Institute of Scientific and Technical Information of China (English)

    JIAO Li-hua; XU Li-mei; HONG Hu

    2007-01-01

    With the required increased audio pressure of the parametric ultrasonic transducer array and the difficulty to theoretically analyse the complex ultrasonic structure in audio beam application, an computafionally efficient model is desired to describe the characteristic of the parametric ultrasonic transducer array for the system design and optimization. By applying the symmetry boundary conditions at the mid-plane in the thickness direction, a finite element model based on the half thickness simplification is presented to analyze the parametric circular transducer which is designed by gluing the poly Vinylidene fluoride film (PVDF). The validity of the proposed model is confirmed by a comparison of finite element aalysis results with the theoretical value and experimental data, which show that they are making a good agreement with each other.

  18. Konstruktion af transducer

    DEFF Research Database (Denmark)

    Henriksen, Lars; Nielsen, Martin Pram

    Formålet med dette midtvejsprojekt er at udarbejde en transducer til måling af pressers stivhed. Dette er gjort på baggrund af en gennemgang af både presse- og stativ-typer samtidig med at udbøjningssituationen beskrives. Der introduceres en ide, der udgør grundkonceptet for opmålingsproceduren o...... færdige transducer – Load cellen. Strain gauge sørger for dataopsamlingen fra load cellen. Disse kalibreres således at transduceren er klar til de videre målinger der ligger i forlængelse af dette projekt....

  19. Glass-windowed ultrasound transducers.

    Science.gov (United States)

    Yddal, Tostein; Gilja, Odd Helge; Cochran, Sandy; Postema, Michiel; Kotopoulis, Spiros

    2016-05-01

    In research and industrial processes, it is increasingly common practice to combine multiple measurement modalities. Nevertheless, experimental tools that allow the co-linear combination of optical and ultrasonic transmission have rarely been reported. The aim of this study was to develop and characterise a water-matched ultrasound transducer architecture using standard components, with a central optical window larger than 10 mm in diameter allowing for optical transmission. The window can be used to place illumination or imaging apparatus such as light guides, miniature cameras, or microscope objectives, simplifying experimental setups. Four design variations of a basic architecture were fabricated and characterised with the objective to assess whether the variations influence the acoustic output. The basic architecture consisted of a piezoelectric ring and a glass disc, with an aluminium casing. The designs differed in piezoelectric element dimensions: inner diameter, ID=10 mm, outer diameter, OD=25 mm, thickness, TH=4 mm or ID=20 mm, OD=40 mm, TH=5 mm; glass disc dimensions OD=20-50 mm, TH=2-4 mm; and details of assembly. The transducers' frequency responses were characterised using electrical impedance spectroscopy and pulse-echo measurements, the acoustic propagation pattern using acoustic pressure field scans, the acoustic power output using radiation force balance measurements, and the acoustic pressure using a needle hydrophone. Depending on the design and piezoelectric element dimensions, the resonance frequency was in the range 350-630 kHz, the -6 dB bandwidth was in the range 87-97%, acoustic output power exceeded 1 W, and acoustic pressure exceeded 1 MPa peak-to-peak. 3D stress simulations were performed to predict the isostatic pressure required to induce material failure and 4D acoustic simulations. The pressure simulations indicated that specific design variations could sustain isostatic pressures up to 4.8 MPa.The acoustic simulations were able to

  20. Glass-windowed ultrasound transducers.

    Science.gov (United States)

    Yddal, Tostein; Gilja, Odd Helge; Cochran, Sandy; Postema, Michiel; Kotopoulis, Spiros

    2016-05-01

    In research and industrial processes, it is increasingly common practice to combine multiple measurement modalities. Nevertheless, experimental tools that allow the co-linear combination of optical and ultrasonic transmission have rarely been reported. The aim of this study was to develop and characterise a water-matched ultrasound transducer architecture using standard components, with a central optical window larger than 10 mm in diameter allowing for optical transmission. The window can be used to place illumination or imaging apparatus such as light guides, miniature cameras, or microscope objectives, simplifying experimental setups. Four design variations of a basic architecture were fabricated and characterised with the objective to assess whether the variations influence the acoustic output. The basic architecture consisted of a piezoelectric ring and a glass disc, with an aluminium casing. The designs differed in piezoelectric element dimensions: inner diameter, ID=10 mm, outer diameter, OD=25 mm, thickness, TH=4 mm or ID=20 mm, OD=40 mm, TH=5 mm; glass disc dimensions OD=20-50 mm, TH=2-4 mm; and details of assembly. The transducers' frequency responses were characterised using electrical impedance spectroscopy and pulse-echo measurements, the acoustic propagation pattern using acoustic pressure field scans, the acoustic power output using radiation force balance measurements, and the acoustic pressure using a needle hydrophone. Depending on the design and piezoelectric element dimensions, the resonance frequency was in the range 350-630 kHz, the -6 dB bandwidth was in the range 87-97%, acoustic output power exceeded 1 W, and acoustic pressure exceeded 1 MPa peak-to-peak. 3D stress simulations were performed to predict the isostatic pressure required to induce material failure and 4D acoustic simulations. The pressure simulations indicated that specific design variations could sustain isostatic pressures up to 4.8 MPa.The acoustic simulations were able to

  1. Nano-optomechanical transducer

    Science.gov (United States)

    Rakich, Peter T; El-Kady, Ihab F; Olsson, Roy H; Su, Mehmet Fatih; Reinke, Charles; Camacho, Ryan; Wang, Zheng; Davids, Paul

    2013-12-03

    A nano-optomechanical transducer provides ultrabroadband coherent optomechanical transduction based on Mach-wave emission that uses enhanced photon-phonon coupling efficiencies by low impedance effective phononic medium, both electrostriction and radiation pressure to boost and tailor optomechanical forces, and highly dispersive electromagnetic modes that amplify both electrostriction and radiation pressure. The optomechanical transducer provides a large operating bandwidth and high efficiency while simultaneously having a small size and minimal power consumption, enabling a host of transformative phonon and signal processing capabilities. These capabilities include optomechanical transduction via pulsed phonon emission and up-conversion, broadband stimulated phonon emission and amplification, picosecond pulsed phonon lasers, broadband phononic modulators, and ultrahigh bandwidth true time delay and signal processing technologies.

  2. Stress wave focusing transducers

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S.R., LLNL

    1998-05-15

    Conversion of laser radiation to mechanical energy is the fundamental process behind many medical laser procedures, particularly those involving tissue destruction and removal. Stress waves can be generated with laser radiation in several ways: creation of a plasma and subsequent launch of a shock wave, thermoelastic expansion of the target tissue, vapor bubble collapse, and ablation recoil. Thermoelastic generation of stress waves generally requires short laser pulse durations and high energy density. Thermoelastic stress waves can be formed when the laser pulse duration is shorter than the acoustic transit time of the material: {tau}{sub c} = d/c{sub s} where d = absorption depth or spot diameter, whichever is smaller, and c{sub s} = sound speed in the material. The stress wave due to thermoelastic expansion travels at the sound speed (approximately 1500 m/s in tissue) and leaves the site of irradiation well before subsequent thermal events can be initiated. These stress waves, often evolving into shock waves, can be used to disrupt tissue. Shock waves are used in ophthalmology to perform intraocular microsurgery and photodisruptive procedures as well as in lithotripsy to fragment stones. We have explored a variety of transducers that can efficiently convert optical to mechanical energy. One such class of transducers allows a shock wave to be focused within a material such that the stress magnitude can be greatly increased compared to conventional geometries. Some transducer tips could be made to operate regardless of the absorption properties of the ambient media. The size and nature of the devices enable easy delivery, potentially minimally-invasive procedures, and precise tissue- targeting while limiting thermal loading. The transducer tips may have applications in lithotripsy, ophthalmology, drug delivery, and cardiology.

  3. Numerical transducer modelling

    DEFF Research Database (Denmark)

    Cutanda, Vicente

    1999-01-01

    Numerical modelling is of importance for the design, improvement and study of acoustic transducers such as microphones and accelerometers. Techniques like the boundary element method and the finite element method are the most common supplement to the traditional empirical and analytical approaches...... errors and instabilities in the computations of numerical solutions. An investigation to deal with this narrow-gap problem has been carried out....

  4. Needle breakage: incidence and prevention.

    Science.gov (United States)

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

    2010-10-01

    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.

  5. Use of an acoustic transponder for US visualization of biopsy needles.

    Science.gov (United States)

    Winsberg, F; Mitty, H A; Shapiro, R S; Yeh, H C

    1991-09-01

    A 20-gauge Chiba needle with a stylet embedded with polyvinyldifluoride (PVDF), a polymer that acts as an acoustic-electric transducer, facilitated a variety of diagnostic and therapeutic ultrasound (US)-guided interventions in nine patients. PVDF receives acoustic energy from the US scanner and transmits an electrical signal through the stylet and a shielded cable to the scanner, which results in appearance of a bright echo on the monitor at the location of the needle tip.

  6. Myocardial wall-thickness transducer

    Science.gov (United States)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H.

    1976-01-01

    Device consists of highly compliant circular beam attached to piezoresistive strain gage and barbed needle. Radial deflection of myocardium is measured with minimal disturbance of normal heart functions.

  7. Transducers for ultrasonic limb plethysmography

    Science.gov (United States)

    Nickell, W. T.; Wu, V. C.; Bhagat, P. K.

    1983-01-01

    The design, construction, and performance characteristics of ultasonic transducers suitable for limb plethysmography are presented. Both 3-mm-diameter flat-plate and 12-mm-diameter hemispheric ceramic transducers operating at 2 MHz were fitted in 1-mm thick epoxy-resin lens/acoustic-coupling structures and mounted in exercie-EKG electrode housings for placement on the calf using adhesive collars. The effects of transducer directional characteristics on performance under off-axis rotation and the electrical impedances of the transducers were measured: The flat transducer was found to be sensitive to rotation and have an impedance of 800 ohms; the hemispheric transducer, to be unaffected by rotation and have an impedance of 80 ohms. The use of hemispheric transducers as both transmitter and receiver, or of a flat transducer as transmitter and a hemispheric transducer as receiver, was found to produce adequate dimensional measurements, with minimum care in transducer placement, in short-term physiological experiments and long-term (up to 7-day) attachment tests.

  8. Fine needle aspiration of the thyroid

    Science.gov (United States)

    Thyroid nodule fine needle aspirate biopsy; Biopsy - thyroid - skinny-needle; Skinny-needle thyroid biopsy ... cleaned. A thin needle is inserted into the thyroid, and a sample of thyroid cells and fluid ...

  9. Optically transduced MEMS magnetometer

    Science.gov (United States)

    Nielson, Gregory N; Langlois, Eric

    2014-03-18

    MEMS magnetometers with optically transduced resonator displacement are described herein. Improved sensitivity, crosstalk reduction, and extended dynamic range may be achieved with devices including a deflectable resonator suspended from the support, a first grating extending from the support and disposed over the resonator, a pair of drive electrodes to drive an alternating current through the resonator, and a second grating in the resonator overlapping the first grating to form a multi-layer grating having apertures that vary dimensionally in response to deflection occurring as the resonator mechanically resonates in a plane parallel to the first grating in the presence of a magnetic field as a function of the Lorentz force resulting from the alternating current. A plurality of such multi-layer gratings may be disposed across a length of the resonator to provide greater dynamic range and/or accommodate fabrication tolerances.

  10. Numerical Transducer Modeling

    DEFF Research Database (Denmark)

    Henriquez, Vicente Cutanda

    This thesis describes the development of a numerical model of the propagation of sound waves in fluids with viscous and thermal losses, with application to the simulation of acoustic transducers, in particular condenser microphones for measurement. The theoretical basis is presented, numerical...... that are allowable in this case: linear variations, absence of flow, harmonic time variation, thermodynamical equilibrium and physical dimensions much larger than the molecular mean free path. A formulation of the BEM is also developed with an improvement designed to cope with the numerical difficulty associated...... with very close surfaces, as found in condenser microphones, where the membrane has a backplate very close behind. This improvement could be useful for many other problems where the BEM is applied. The numerical implementation that includes both viscous and thermal effects is then worked out. Some numerical...

  11. Calibration of Underwater Sound Transducers

    Directory of Open Access Journals (Sweden)

    H.R.S. Sastry

    1983-07-01

    Full Text Available The techniques of calibration of underwater sound transducers for farfield, near-field and closed environment conditions are reviewed in this paper .The design of acoustic calibration tank is mentioned. The facilities available at Naval Physical & Oceanographic Laboratory, Cochin for calibration of transducers are also listed.

  12. Mechanics of needle-tissue interaction

    NARCIS (Netherlands)

    Roesthuis, Roy J.; Veen, van Youri R.J.; Jahya, Alex; Misra, Sarthak

    2011-01-01

    When a needle is inserted into soft tissue, interac- tion forces are developed at the needle tip and along the needle shaft. The needle tip force is due to cutting of the tissue, and the force along the needle shaft is due to friction between needle and tissue. In this study, the friction force is d

  13. Circuit for Driving Piezoelectric Transducers

    Science.gov (United States)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  14. A Direct Driver for Electrostatic Transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...

  15. Frequency Steered Acoustic Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is to develop, fabricate, and characterize a novel frequency steered acoustic transducer (FSAT) for the...

  16. Transducer Field Imaging Using Acoustography

    Directory of Open Access Journals (Sweden)

    Jaswinder S. Sandhu

    2012-01-01

    Full Text Available A common current practice for transducer field mapping is to scan, point-by-point, a hydrophone element in a 2D raster at various distances from the transducer radiating surface. This approach is tedious, requiring hours of scanning time to generate full cross-sectional and/or axial field distributions. Moreover, the lateral resolution of the field distribution image is dependent on the indexing steps between data points. Acoustography is an imaging process in which an acousto-optical (AO area sensor is employed to record the intensity of an ultrasound wavefield on a two-dimensional plane. This paper reports on the application of acoustography as a simple but practical method for assessing transducer field characteristics. A case study performed on a commercial transducer is reported, where the radiated fields are imaged using acoustography and compared to the corresponding quantities that are predicted numerically.

  17. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    OpenAIRE

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2014-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at ...

  18. Pressure Transducer Has Long Service Life

    Science.gov (United States)

    Prout, R. E.; Chaves, A. J.

    1982-01-01

    Differential-pressure transducer includes a piston, helical springs, and a linear variable-differential transformer concentric with piston. Transducer senses motion of piston in response to changes in pressure differential. Eight seals within the transducer prevent fluid leakage from one pressure line to the other. Reliability and operating life of the new unit are superior to many conventional transducers.

  19. Characterization of Dielectric Electroactive Polymer transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Møller, Martin B.; Sarban, Rahimullah;

    2014-01-01

    This paper analysis the small-signal model of the Dielectric Electro Active Polymer (DEAP) transducer. The DEAP transducer have been proposed as an alternative to the electrodynamic transducer in sound reproduction systems. In order to understand how the DEAP transducer works, and provide guideli...

  20. Ultrasonic Transducer Irradiation Test Results

    International Nuclear Information System (INIS)

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric transducer and two

  1. Ultrasonic Transducer Irradiation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Palmer, Joe [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Keller, Paul [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Kohse, Gordon [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Tittmann, Bernhard [Pennsylvania State Univ., University Park, PA (United States); Reinhardt, Brian [Pennsylvania State Univ., University Park, PA (United States); Rempe, Joy [Rempe and Associates, Idaho Falls, ID (United States)

    2015-02-01

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric

  2. Smart needles for percutaneous interventions

    NARCIS (Netherlands)

    Henken, K.R.

    2014-01-01

    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

  3. Ultrasound transducer assembly and method for manufacturing an ultrasound transducer assembly

    NARCIS (Netherlands)

    Dekker, R.; Henneken, V.A.; Louwerse, M.C.; Raganato, M.F.

    2015-01-01

    The present invention relates to an ultrasound transducer assembly (10), in particular for intravascular ultrasound systems. The ultrasound transducer assembly comprises at least one silicon substrate element (30) including an ultrasound transducer element (14) for emitting and receiving ultrasound

  4. Pressure transducers for cryogenic liquids

    OpenAIRE

    Pavlovskyy I. V.; Kutrakov A. P.; Maryamova I. I.; Druzhinin A. A.

    2007-01-01

    The developed universal construction of tensoresistive pressure transducer for cryogenic liquids (liquid nitrogen and liquid helium) is described. The study of strain gauges characteristics on the basis of p-type Si whiskers with different boron concentration, mounted on the invar spring elements (beams), in the wide ranges of strain ε=±1,2·10-3 and temperature 4,2-300 К for transducers simulation were carried out. It was shown that using heavily doped silicon strain gages gives the possibili...

  5. Proceedings of transducer 84 conference

    International Nuclear Information System (INIS)

    In the broad and varied field of sensors this conference reviews thermal sensors for temperature measurements, gas sensors for gas analysis (for example analysis of exhaust gases from vehicles), optical fiber sensors, applications for optics, mechanics, robotics and signal processing. In particular one of the applications concerns acoustical transducers operating in liquid sodium for LMFBR reactors

  6. Calculations for Piezoelectric Ultrasonic Transducers

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1986-01-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a boay which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation...

  7. Irradiation Testing of Ultrasonic Transducers

    International Nuclear Information System (INIS)

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

  8. Irradiation Testing of Ultrasonic Transducers

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2014-07-30

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  9. PMN-PT single crystal thick films on silicon substrate for high-frequency micromachined ultrasonic transducers

    Energy Technology Data Exchange (ETDEWEB)

    Peng, J.; Lau, S.T.; Chao, C.; Dai, J.Y.; Chan, H.L.W. [The Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Center, Hong Kong (China); Luo, H.S. [Chinese Academy of Sciences, The State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Shanghai (China); Zhu, B.P.; Zhou, Q.F.; Shung, K.K. [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States)

    2010-01-15

    In this work, a novel high-frequency ultrasonic transducer structure is realized by using PMNPT-on-silicon technology and silicon micromachining. To prepare the single crystalline PMNPT-on-silicon wafers, a hybrid processing method involving wafer bonding, mechanical lapping and wet chemical thinning is successfully developed. In the transducer structure, the active element is fixed within the stainless steel needle housing. The measured center frequency and -6 dB bandwidth of the transducer are 35 MHz and 34%, respectively. Owing to the superior electromechanical coupling coefficient (k{sub t}) and high piezoelectric constant (d{sub 33}) of PMNPT film, the transducer shows a good energy conversion performance with a very low insertion loss down to 8.3 dB at the center frequency. (orig.)

  10. Transducers and Arrays for Underwater Sound

    CERN Document Server

    Sherman, Charles H

    2007-01-01

    This book is concerned with the theory, development and design of electroacoustic transducers for underwater applications, and is more comprehensive than any existing book in this field. It includes the basics of the six major types of electroacoustic transducers, with emphasis on the piezoelectric ceramic transducers that are currently most widely used. It presents the basic acoustics, as well as specific acoustic data, needed in transducer design and includes analysis of nonlinear effects in transducers. A large number of specific transducer designs, including both projectors and hydrophones, are described in detail as well as methods of modeling, evaluation and measurement. Analysis of transducer arrays, including the effects of mutual radiation impedance, as well as numerical models for transducers and arrays are also covered. The book contains an extensive Appendix of useful current information, including data on the latest transduction materials, and numerous diagrams that will facilitate its use by stu...

  11. Measuring Thicknesses With In Situ Ultrasonic Transducers

    Science.gov (United States)

    Dunn, Daniel E.; Cerino, Joseph R.

    1995-01-01

    Several pulsed ultrasonic transducers attached to workpiece for measurement of changes in thicknesses of workpiece at transducer locations during grinding and polishing, according to proposal. Once attached, each transducer remains attached at original position until all grinding and polishing operations complete. In typical application, workpiece glass or ceramic blank destined to become component of optical system.

  12. Power Generation Using Piezoelectric Transducer

    Directory of Open Access Journals (Sweden)

    Tanu Chouhan

    2016-05-01

    Full Text Available The most basic need of today’s world is energy which is non-renewable source of energy available on earth. The need is increasing day by day, to overcome this there is requirement of energy harvesting. This paper attempts to show how man has been utilizing and optimizing kinetic energy. Current work also illustrates the working principle of piezoelectric crystal and various sources of vibration for the crystal. “The idea of energy harvesting is applicable to sensors as well as transducers that are placed and operated on some entities for a long time to replace the sensor module batteries. Such sensors are commonly called self-powered sensors.” Embarked piezoelectric transducer, which is an electromechanical converter, undergoes mechanical vibrations therefore produce electricity. This power source has many applications as in agriculture, home application and street lighting and as energy source for sensors in remote locations.

  13. Mechanical performance of disposable surgical needle holders.

    Science.gov (United States)

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

    1992-01-01

    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.

  14. 3D transrectal ultrasound prostate biopsy using a mechanical imaging and needle-guidance system

    Science.gov (United States)

    Bax, Jeffrey; Cool, Derek; Gardi, Lori; Montreuil, Jacques; Gil, Elena; Bluvol, Jeremy; Knight, Kerry; Smith, David; Romagnoli, Cesare; Fenster, Aaron

    2008-03-01

    Prostate biopsy procedures are generally limited to 2D transrectal ultrasound (TRUS) imaging for biopsy needle guidance. This limitation results in needle position ambiguity and an insufficient record of biopsy core locations in cases of prostate re-biopsy. We have developed a multi-jointed mechanical device that supports a commercially available TRUS probe with an integrated needle guide for precision prostate biopsy. The device is fixed at the base, allowing the joints to be manually manipulated while fully supporting its weight throughout its full range of motion. Means are provided to track the needle trajectory and display this trajectory on a corresponding TRUS image. This allows the physician to aim the needle-guide at predefined targets within the prostate, providing true 3D navigation. The tracker has been designed for use with several end-fired transducers that can be rotated about the longitudinal axis of the probe to generate 3D images. The tracker reduces the variability associated with conventional hand-held probes, while preserving user familiarity and procedural workflow. In a prostate phantom, biopsy needles were guided to within 2 mm of their targets, and the 3D location of the biopsy core was accurate to within 3 mm. The 3D navigation system is validated in the presence of prostate motion in a preliminary patient study.

  15. High temperature ultrasonic transducers: review

    OpenAIRE

    Kažys, R.; Voleišis, A.; Voleišienė, B.

    2008-01-01

    The problems of development of high-temperature ultrasonic transducers for modern science and technology applications are analysed. More than 10 piezoelectric materials suitable for operation at high temperatures are overviewed. It is shown that bismuth titanate based piezoelectric elements are most promisable. Bonding methods of piezoelectric elements to a protector and backing are discussed. Thermosonic gold-to-gold bonding is most modern and possesses unique features. Our achievements in t...

  16. Elongation Transducer For Tensile Tests

    Science.gov (United States)

    Roberts, Paul W.; Stokes, Thomas R.

    1994-01-01

    Extensometer transducer measures elongation of tensile-test specimen with negligible distortion of test results. Used in stress-versus-strain tests of small specimens of composite materials. Clamping stress distributed more evenly. Specimen clamped gently between jaw and facing surface of housing. Friction force of load points on conical tips onto specimen depends on compression of spring, adjusted by turning cover on housing. Limp, light nylon-insulated electrical leads impose minimal extraneous loads on measuring elements.

  17. Endoscopic Therapeutic Device Using Focused Ultrasonic Small Transducer

    Science.gov (United States)

    Yasui, Akihiro; Haga, Yoichi; Chen, Jiun-Jie; Iseki, Hiroshi; Esashi, Masayoshi; Wada, Hiroshi

    In this research, an ultrasonic probe (5.5 mm in diameter), which has a concave PZT transducer at its tip, was fabricated for ultrasonic treatments such as sonoporation and sonodynamic therapy in the human body using a catheter and/or endoscope. Ultrasound has the potential to enhance cytotoxicity of drugs such as porphyrins, a process referred to as sonodynamic therapy, and also to deliver macromolecules such as plasmid DNA, a process referred to as sonoporation. The fabricated probe was then experimentally characterized by measuring the acoustic intensity distribution around the focal point, using a PVDF needle-type ultrasonic hydrophone. When the PZT transducer was driven by a 120 Volts peak-to-peak AC signal at 1.83 MHz, the ultrasound output was successfully focused at the focal point, with a peak intensity of 24.9 W/cm2 (0.87 MPa). Using the fabricated probe, cultured Chinese Hamster Ovary (CHO) cells were exposed to ultrasound (1.83 MHz, continuous wave, peak acoustic pressure of 0.5 MPa) for 2 s in the presence of microbubbles MB-3 and Green Fluorescent Protein (GFP) plasmid DNA. As a result of sonication, the expression of GFP was observed in CHO cells.

  18. Transducers

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    stream_size 27 stream_content_type text/plain stream_name Encycl_Microcomputers_18_335.pdf.txt stream_source_info Encycl_Microcomputers_18_335.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  19. Radiation-resistant pressure transducers

    International Nuclear Information System (INIS)

    Full text : The sensitive element of vibrofrequency tensor converter (VTC) is an electromechanical resonator of string type with electrostatic excitation of longitudinal mechanical vibrations. The string is made from tensosensitive thread-like monocrystal n-Ge1-x Six (length 1-5 mm, diameter 8-12 mcm) with current outlet and strictly fixed by ends at plate or deformable surface (in elastic element) at 50 mcm apartheid. With increasing Si atomic percent in n-Ge1-x Six the converter tens sensitivity increases. There has been shown the scheme of pressure transducer which contains monocrystalline silicon membrane and string tens converter from thread-like monocrystal Ge-Si. Using method, when crystal position on membrane while it deforms by pressure, corresponds to free (uptight) state, allowed to obtain the maximum sensitivity in measurement of pressure fluctuation. The transducers of absolute and pressure differential of this type can be used in automated systems of life activity. The high sensitivity of string transducers to pressure exceeding 100 hertz/mm (water column) permits to use them in devices for measuring gas concentration. The combination of optical and deformation methods of measurements forms the basis of their operation. The pressure change occurs due to the fact that gas molecules absorbing the quanta of incident light, become at excited state and then excitation energy of their vibrational-rotatory degrees of freedom converts to the energy of translational motion of molecules, i.e. to heat appropriate to pressure increase. Using these tens converters of high pressure one can prevent the possible accidents on oil pipe-like Baku-Tibilisi-Ceyhan

  20. Transducers and arrays for underwater sound

    CERN Document Server

    Butler, John L

    2016-01-01

    This improved and updated second edition covers the theory, development, and design of electro-acoustic transducers for underwater applications. This highly regarded text discusses the basics of piezoelectric and magnetostrictive transducers that are currently being used as well as promising new designs. It presents the basic acoustics as well as the specific acoustics data needed in transducer design and evaluation. A broad range of designs of projectors and hydrophones are described in detail along with methods of modeling, evaluation, and measurement. Analysis of projector and hydrophone transducer arrays, including the effects of mutual radiation impedance and numerical models for elements and arrays, are also covered. The book includes new advances in transducer design and transducer materials and has been completely reorganized to be suitable for use as a textbook, as well as a reference or handbook. The new edition contains updates to the first edition, end-of-chapter exercises, and solutions to select...

  1. Analog circuit for controlling acoustic transducer arrays

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas S. (Cedar Crest, NM)

    1991-01-01

    A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.

  2. Mechanical and electrical characteristics of cymbal transducer

    Institute of Scientific and Technical Information of China (English)

    WANG Guangcan; ZHANG Jin; TIAN Wenjie; LIN Guoguang; LIAN Guandong; ZHANG Fuxue

    2005-01-01

    The electromechanical of Cymbal transducer has been researched. Under simple supporting condition, the mechanical and electrical characteristics have been analyzed by using Piezoelectric-elastic theory, Kirchhoff's thin shell vibration theory, Rayleigh-Ritz's theory and equivalent circuit method. The approximate solution and series resonance frequency equation have been given. Under no load, equivalent circuit, correlation parameters of cymbal transducer and the relations between the ratio of cavity depth to radius of Cymbal transducer with resonance frequency, electromechanical coupling coefficient of cymbal transducer have been researched. The best electromechanical coupling coefficient of cymbal transducer has been gained from the results of numerical analysis. It offers a valid theoretical foundation for optimum design of cymbal transducer.

  3. Needle biopsy of the breast.

    Science.gov (United States)

    Millis, R R

    1984-01-01

    Recently, there has been a considerable increase in the use of both fine-needle aspiration biopsy (aspiration cytology) and tissue-core needle biopsy of the breast. In patients with suspected breast cancer, needle biopsy is frequently used to confirm the diagnosis before treatment is planned. This allows a more thoughtful approach to the patient and full screening for possible metastatic disease prior to definitive surgery. Needle biopsy techniques are simple, rapid, can be performed in the doctor's office, and save time, equipment, and hospital beds. Complications are few. Aspiration cytology has the advantage that it is quick to perform, the preparation can be examined almost immediately and, in the event of an unsatisfactory smear, the procedure can be repeated. However, the diagnosis is based on purely cytological evaluation, and the information obtained is somewhat limited. Reported accuracy rates range from 42 to 96%. False positive reports are rare but have occurred in most centers, and a high degree of accuracy will only be obtained by experienced practitioners. Tissue-core needle biopsy has the advantage that the diagnosis is based on histopathological assessment, but the procedure is slightly more time consuming, is more traumatic for the patient, and the equipment is more expensive. Accuracy rates range from 67 to 98.5%. During the past 4 years, 329 tissue-core (Tru-Cut) biopsies have been performed in the Guy's Hospital Breast Unit, with an accuracy rate of 83% in the diagnosis of carcinoma. The procedure has been acceptable to most patients, and complications have been minimal. Studies comparing the use of aspiration cytology and tissue-core needle biopsy in the diagnosis of mammary carcinoma have produced variable results. Both methods have advantages and disadvantages, and the choice of technique must depend on the clinical situation and the preferences and skills of the practitioners involved in the management of the patient. PMID:6377049

  4. Silicon Integrated Cavity Optomechanical Transducer

    Science.gov (United States)

    Zou, Jie; Miao, Houxun; Michels, Thomas; Liu, Yuxiang; Srinivasan, Kartik; Aksyuk, Vladimir

    2013-03-01

    Cavity optomechanics enables measurements of mechanical motion at the fundamental limits of precision imposed by quantum mechanics. However, the need to align and couple devices to off-chip optical components hinders development, miniaturization and broader application of ultrahigh sensitivity chip-scale optomechanical transducers. Here we demonstrate a fully integrated and optical fiber pigtailed optomechanical transducer with a high Q silicon micro-disk cavity near-field coupled to a nanoscale cantilever. We detect the motion of the cantilever by measuring the resonant frequency shift of the whispering gallery mode of the micro-disk. The sensitivity near the standard quantum limit can be reached with sub-uW optical power. Our on-chip approach combines compactness and stability with great design flexibility: the geometry of the micro-disk and cantilever can be tailored to optimize the mechanical/optical Q factors and tune the mechanical frequency over two orders of magnitudes. Electrical transduction in addition to optical transduction was also demonstrated and both can be used to effectively cool the cantilever. Moreover, cantilevers with sharp tips overhanging the chip edge were fabricated to potentially allow the mechanical cantilever to be coupled to a wide range of off-chip systems, such as spins, DNA, nanostructures and atoms on clean surfaces.

  5. Evaluation of pressure transducers. Dynamic tests

    International Nuclear Information System (INIS)

    The evaluation of a pressure transducer consists in checking its specifications. The tests of rapidity with a shock tube are important because they allow to find out transducer response time under a pressure step and also its natural frequency and damping. These last two data define the whole dynamic work of a fast transducer as the accuracy of the amplitude versus frequency function, the phase rotation, limit of use, overload. Several tests carried out on ETCA shock tube are described

  6. Autosizing Control Panel for Needle Bearing

    OpenAIRE

    Prof.A.R.Wadhekar,; Ms Jyoti R. Rajput

    2016-01-01

    A needle roller bearing is a bearing which uses small cylindrical rollers. Bearings are used to reduce friction of any rotating surface. Needle bearings have a large surface in contact with the bearing outer surfaces as compared to ball bearings. There is less added clearance(Diameter of the shaft and the diameter of the bearing are different) so they are much compact. The structure consists of a needle cage which contains the needle rollersthemselves and an outer race (The housin...

  7. Dry needling — peripheral and central considerations

    OpenAIRE

    Dommerholt, Jan

    2011-01-01

    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...

  8. Usefulness of ultrasound-guided core needle biopsy in the diagnosis of cervical lymphadenopathy

    International Nuclear Information System (INIS)

    To evaluate the efficacy of ultrasound-guided percutaneous core-needle biopsy in establishing histopathologic diagnoses of cervical lymphadenopathy. Seventy nine patients with cervical lymphadenopathy without a history of malignancy or recent infection underwent ultrasound-guided core-needle biopsies. Lymph node tissues were obtained by 2 to 4 times of freehand core-needle biopsy technique using a 7.5-12 MHz ultrasound transducer and a short-excursion (12 mm), spring-loaded automated gun with an 16-gauge cutting needle. We evaluated diagnostic yields of biopsies and related complication. Histologic diagnoses were conclusive in 73 cases (92.4%) including 57 benign causes (24 cases of tuberculous lymphadenitis, 19 cases of reactive hyperplasia, 14 cases of Kikuchi Disease and 2 cases of nonspecific lymphadenitis) and 12 malignancies (8 cases of metastatic lymphadenopathy, 7 cases of lymphoma). In 5 of 7 patients with lymphoma, histologic subclassification was established with obtained tissue to guide treatment. No complications were seen after biopsy. Ultrasound-guided core-needle biopsy of cervical lymphadenopathy is a safe, minimally invasive alternative to surgical biopsy, enabling a histologic diagnosis for treatment planning in the majority of cases.

  9. In-plane ultrasonic needle tracking using a fiber-optic hydrophone

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Wenfeng, E-mail: wenfeng.xia@ucl.ac.uk; Desjardins, Adrien E. [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT (United Kingdom); Mari, Jean Martial [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom and GePaSud, University of French Polynesia, Faa’a 98702, French Polynesia (France); West, Simeon J. [Department of Anaesthesia, University College Hospital, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU (United Kingdom); Ginsberg, Yuval; David, Anna L. [Institute for Women’s Health, University College London, 86-96 Chenies Mews, London WC1E 6HX (United Kingdom); Ourselin, Sebastien [Center for Medical Imaging Computing, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2015-10-15

    Purpose: Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real-time image guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber-optic ultrasound receiver in conjunction with the imaging probe used to acquire B-mode ultrasound images. Methods: Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber-optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B-mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third. Results: During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal-to-noise (SNR) of the needle tip was found to depend on the insertion angle. With

  10. Effect and Safety of Deep Needling and Shallow Needling for Functional Constipation

    OpenAIRE

    Wu, Jiani; Liu, Baoyan; Li, Ning; Sun, Jianhua; Wang, Lingling; Wang, Liping; Cai, Yuying; Ye, Yongming; Liu, Jun; Wang, Yang; Liu, Zhishun

    2014-01-01

    Abstract Aupuncture is widely used for functional constipation. Effect of acupuncture might be related to the depth of needling; however, the evidence is limited. This trial aimed to evaluate the effect and safety of deep needling and shallow needling for functional constipation, and to assess if the deep needling and shallow needling are superior to lactulose. We conducted a prospective, superiority-design, 5-center, 3-arm randomized controlled trial. A total of 475 patients with functional ...

  11. Linearization of resistance thermometers and other transducers

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1970-01-01

    Given a resistive transducer which responds directly or indirectly to a physical quantity x, it is shown that the relationship may be linearized by linear methods if and only if both the resistance and conductance of the transducer are concave upward as functions of x. This result applies to eith...

  12. Pushdown machines for the macro tree transducer

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1986-01-01

    The macro tree transducer can be considered as a system of recursive function procedures with parameters, where the recursion is on a tree (e.g., the syntax tree of a program). We investigate characterizations of the class of tree (tree-to-string) translations which is induced by macro tree transduc

  13. Biomechanical performance of new cardiovascular needles.

    Science.gov (United States)

    Thacker, J G; Ferguson, R E; Rodeheaver, G T; Edlich, R F

    2001-01-01

    Cardiovascular needles are now being manufactured from new stainless steel alloys containing high concentrations of nickel, Surgalloy and Ethalloy. The purpose of this study was to compare the biomechanical performance of a cardiovascular needle made of Surgalloy with a comparably sized needle made of Ethalloy. The parameters of biomechanical performance included sharpness, maintenance of sharpness, resistance to bending, and ductility. Because the biomechanical performance of these needles was remarkably similar, cardiovascular needles made of either the Surgalloy or Ethalloy alloys are recommended for cardiovascular surgery. PMID:11495105

  14. Micromachined Integrated Transducers for Ultrasound Imaging

    DEFF Research Database (Denmark)

    la Cour, Mette Funding

    The purpose of this project is to develop capacitive micromachined ultrasonic transducers (CMUTs) for medical imaging. Medical ultrasound transducers used today are fabricated using piezoelectric materials and bulk processing. To fabricate transducers capable of delivering a higher imaging...... resolution it is however necessary to develop new fabrication methods that allows fabrication of transducer elements with smaller dimensions. By using microfabrication technology it is possible to push the dimensions down and provide higher design flexibility. This project is part of a large ultrasound...... project and collaboration with a lot of partners to improve medical ultrasound imaging. The focus in this part of the project is to design, fabricate and characterize 1D CMUT arrays. Two versions of 1D transducers are made, one at Stanford University and one at DTU. Electrical and acoustical...

  15. Electrical modeling of dielectric elastomer stack transducers

    Science.gov (United States)

    Haus, Henry; Matysek, Marc; Moessinger, Holger; Flittner, Klaus; Schlaak, Helmut F.

    2013-04-01

    Performance of dielectric elastomer transducers (DEST) depends on mechanical and electrical parameters. For designing DEST it is therefore necessary to know the influences of these parameters on the overall performance. We show an electrical equivalent circuit valid for a transducer consisting of multiple layers and derive the electrical parameters of the circuit depending on transducers geometry and surface resistivity of the electrodes. This allows describing the DESTs dynamic behavior as a function of fabrication (layout, sheet and interconnection resistance), material (breakdown strength, permittivity) and driving (voltage) parameters. Using this electrical model transfer function and cut-off frequency are calculated, describing the influence of transducer capacitance, resistance and driving frequency on the achievable actuation deflection. Furthermore non ideal boundary effects influencing the capacitance value of the transducer are investigated by an electrostatic simulation and limits for presuming a simple plate capacitor model for calculating the transducer capacitance are derived. Results provide the plate capacitor model is a valid assumption for typical transducer configurations but for certain aspect ratios of electrode dimensions to dielectric thickness -- arising e.g. in the application of tactile interfaces -- the influence of boundary effects is to be considered.

  16. Compact Orthomode Transducers Using Digital Polarization Synthesis

    CERN Document Server

    Morgan, Matthew A; Boyd, Tod A

    2010-01-01

    In this paper we present a novel class of compact orthomode transducers which use digital calibration to synthesize the desired polarization vectors while maintaining high isolation and minimizing mass and volume. These digital orthomode transducers consist of an arbitrary number of planar probes in a circular waveguide, each of which is connected to an independent receiver chain designed for stability of complex gain. The outputs of each receiver chain are then digitized and combined numerically with calibrated, complex coefficients. Measurements on two prototype digital orthomode transducers, one with three probes and one with four, show better than 50 dB polarization isolation over a 10 C temperature range with a single calibration.

  17. Hybrid piezoelectric energy harvesting transducer system

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

    2008-01-01

    A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

  18. Dry needling - peripheral and central considerations.

    Science.gov (United States)

    Dommerholt, Jan

    2011-11-01

    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. Ultrasonic wave transducer for high temperature barrier

    International Nuclear Information System (INIS)

    This transducer is made by a metallic body pivoting on a support fixed to the barrier and an internal vitroceramic waveguide in contact on the barrier and on the other end on a piezoelectric ceramic element

  20. Performance of Honeywell silicon pressure transducers

    Digital Repository Service at National Institute of Oceanography (India)

    VijayKumar, K.; Joseph, A.; Desai, R.G.P.; Nagvekar, S.; Prabhudesai, S.; Damodaran, V.

    Simultaneous calibration of three Honeywell pressure transducers (PPTR) at four ambient temperatures have been carried out using a novel static calibration system developed in-house. Calibration results indicated that differing PPTRs exhibited...

  1. Usefulness of Core Needle Biopsy for Thyroid Nodules with Macrocalcifications: Comparison with Fine-Needle Aspiration

    OpenAIRE

    Yi, Kyung Sik; Kim, Ji-Hoon; Na, Dong Gyu; Seo, Hyobin; Min, Hye Sook; Won, Jae-Kyung; Yun, Tae Jin; Ryoo, Inseon; Kim, Su Chin; Choi, Seung Hong; Sohn, Chul-Ho

    2015-01-01

    Background: This study was performed to determine the benefits of core needle biopsy (CNB), as compared with fine-needle aspiration (FNA), for the diagnosis of thyroid nodules with macrocalcifications.

  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

    2003-01-01

    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. Exploration of New Electroacupuncture Needle Material

    OpenAIRE

    Sanghun Lee; Gwang-Ho Choi; Chang Hoon Lee; Yu Kyoung Kim; Saebhom Lee; Sungjin Cho; Sunhee Yeon; Sun-Mi Choi; Yeon-Hee Ryu

    2012-01-01

    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 microsco...

  4. Development of High Frequency Miniature Ultrasound Transducers

    OpenAIRE

    Manh, Tung

    2013-01-01

    Small, high frequency (≥ 10MHz) broadband ultrasound transducers are required in modern medical imaging systems to provide short range, high resolution images for studying of microstructures in soft tissues, such as the composition of small tumors or a vessel wall. The manufacturing of these probes using conventional methods, i.e. lapping and dicing, becomes difficult and expensive for high frequency applications and there is a need to produce small ultrasound transducers with low cost and hi...

  5. Piezoelectric and acoustic materials for transducer applications

    CERN Document Server

    Safari, Ahmad

    2008-01-01

    Discusses the underlying physical principles of piezoelectric materials, important properties of ferroelectric/piezoelectric materials used in today's transducer technology, and the principles used in transducer designIncludes examples of a wide range of applications of such materials along with the appertaining rationalesProvides a comprehensive, yet concise, reference to all the pertinent aspects of piezoelectric materialsContains contributions from a select-group of distinguished researchers

  6. Design considerations for piezoelectric polymer ultrasound transducers.

    Science.gov (United States)

    Brown, L F

    2000-01-01

    Much work has been published on the design of ultrasound transducers using piezoelectric ceramics, but a great deal of this work does not apply when using the piezoelectric polymers because of their unique electrical and mechanical properties. The purpose of this paper is to review and present new insight into seven important considerations for the design of active piezoelectric polymer ultrasound transducers: piezoelectric polymer materials selection, transducer construction and packaging requirements, materials characterization and modeling, film thickness and active area design, electroding selection, backing material design, and front protection/matching layer design. Besides reviewing these design considerations, this paper also presents new insight into the design of active piezoelectric polymer ultrasonic transducers. The design and fabrication of an immersible ultrasonic transducer, which has no adhesive layer between the active element and backing layer, is included. The transducer features direct deposition of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer onto an insulated aluminum backing substrate. Pulse-echo tests indicated a minimum insertion loss of 37 dB and -6 dB bandwidth of 9.8 to 22 MHz (71%). The use of polymer wear-protection/quarter-wave matching layers is also discussed. Test results on a P(VDF-TrFE) transducer showed that a Mylar/sup TM/ front layer provided a slight increase in pulse-echo amplitude of 15% (or 1.2 dB) and an increase in -6 dB pulse-echo fractional bandwidth from 86 to 95%. Theoretical derivations are reported for optimizing the active area of the piezoelectric polymer element for maximum power transfer at resonance. These derivations are extended to the special case for a low profile (i.e., thin) shielded transducer. A method for modeling the non-linear loading effects of a commercial pulser-receiver is also included.

  7. Freehand biopsy guided by electromagnetic needle tracking

    DEFF Research Database (Denmark)

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

    2011-01-01

    To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....

  8. Tetrahedral mesh for needle insertion

    OpenAIRE

    Syvertsen, Rolf Anders

    2007-01-01

    This is a Master’s thesis in how to make a tetrahedral mesh for use in a needle insertion simulator. It also describes how it is possible to make the simulator, and how to improve it to make it as realistic as possible. The medical simulator uses a haptic device, a haptic scene graph and a FEM for realistic soft tissue deformation and interaction. In this project a tetrahedral mesh is created from a polygon model, and then the mesh has been loaded into the HaptX haptic scene graph. The object...

  9. [Inductance transducers for borderline localization of metallic foreign bodies].

    Science.gov (United States)

    Pudov, V I; Reutov, Iu Ia; Korotkikh, S A

    1996-01-01

    The paper outlines the advantages and disadvantages of a ferroprobe inductance transducer used in the borderline localization of a foreign ferromagnetic body. To eliminate the ferroprobe transducer-inherent disadvantages, a whirl-current inductance transducer has been developed. The transducer localizes a foreign nonferromagnetic and ferromagnetic body in its borderline localization in the eye and in the whole body.

  10. Autosizing Control Panel for Needle Bearing

    Directory of Open Access Journals (Sweden)

    Prof.A.R.Wadhekar,

    2016-02-01

    Full Text Available A needle roller bearing is a bearing which uses small cylindrical rollers. Bearings are used to reduce friction of any rotating surface. Needle bearings have a large surface in contact with the bearing outer surfaces as compared to ball bearings. There is less added clearance(Diameter of the shaft and the diameter of the bearing are different so they are much compact. The structure consists of a needle cage which contains the needle rollersthemselves and an outer race (The housing itself. Radial bearings are cylindrical and they use rollers parallel to the axis of the shaft. Radial pattern of needle are being used by thrust needles. Complement bearings have solid inner as well as outer rings and rib-guided cylindrical rollers. The bearings have the largest number of rolling elements and also have extremely high radial load carrying capacity and are suitable for compact designs.Needle roller bearings have relatively small diameter cylindrical rolling elements whose length is much larger than their diameter. As compared to other types of rolling bearings, needle roller bearings possess a small cross-sectional height and significant load-bearing capacity and rigidity relative to their volume. Also, because the inertial force acting on them is limited, needle bearings are an ideal choice for applications with oscillating motion. These bearings also work well in compact and lightweight machine designs and they serve as a ready replacement for sliding bearings. Needle bearings features are great rigidity, smaller cross-section, higher loadcarrying capacity, and has lower inertia forces that facilitate to size and weight reductions in machinery. Needle bearings are designed to stand in oscillation, performwell under any conditions, and interchange with the sliding of bearings.

  11. Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

    Science.gov (United States)

    ... Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ultrasound-guided thyroid biopsy ... Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During a fine needle aspiration ...

  12. Estimating needle-tissue interaction forces for hollow needles using fiber Bragg grating sensors

    Science.gov (United States)

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

    2016-03-01

    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.

  13. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    Science.gov (United States)

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  14. [Fine needle aspiration cytology of mammography screening

    DEFF Research Database (Denmark)

    Engvad, B.; Laenkholm, A.V.; Schwartz, Thue W.;

    2009-01-01

    diagnostic classes were introduced. The aim of this study was to evaluate the quality assurance programme in a screening population to determine whether fine needle aspiration cytology (FNAC) as first choice remains a useful tool in the preoperative diagnostics, or if needle core biopsy should be the first...

  15. An Elementary Account of Needle Insertion

    Institute of Scientific and Technical Information of China (English)

    张文兵; 霍则军

    2004-01-01

    @@ 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.

  16. Needle-Tissue Interaction by Experiment

    NARCIS (Netherlands)

    Van Gerwen, D.J.

    2013-01-01

    Medical needles may not be very popular among patients, but they are exceptionally versatile instruments that have found their way into virtually every clinical intervention imaginable. However, despite their versatility, needles can be very difficult to use, and there is much room for improvement.

  17. Freehand biopsy guided by electromagnetic needle tracking

    DEFF Research Database (Denmark)

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

    2011-01-01

    To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....

  18. [Textual research on the fire needle and the fire needle therapy].

    Science.gov (United States)

    Liu, T; Zhu, J P; Zhang, Q C

    2016-03-01

    There are different names of the fire needle therapy in the Huang di nei jing (Inner Canon of Huangdi) such as Zu-zhen (), Cui-zhen (,), Fan-zhen (), Huo-cui (), Cui (,,), Cuici ,), Fan zhen jie ci (). It is claimed that the lance needle, the round sharp needle and the long needle recorded in this Classic are puncturing tools for the fire needle therapy. In the Eastern Han Dynasty, Zhang Zhongjing expanded the indications for the fire needle therapy and Huo-zhen () firstly appeared in the Jin kui yu han jing(Classic of the Jade Box and Golden Chamber). The application of the fire needle therapy had been further expanded to a lot of internal and external disorders form the Wei-Jin-Southern and Northern Dynasties to the Ming and Qing Dynasties. There are more detailed records on the manipulation and the tools of the fire needle therapy during this period. In the 1970s, Huo zhen liao fa () was proposed and still in use today. However the Bai-zhen (plain needle) in ancient literature is equal to the filiform needle and should not be regarded as the former name of the fire needle. PMID:27255194

  19. High Temperature, High Power Piezoelectric Composite Transducers

    Directory of Open Access Journals (Sweden)

    Hyeong Jae Lee

    2014-08-01

    Full Text Available Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  20. Development of high temperature ultrasonic transducers

    International Nuclear Information System (INIS)

    Structural health monitoring (SHM) techniques are needed to maintain the reliability of power plants for long term operation. The high temperature transducers are necessary to realize SHM (monitor wall thickness of the pipings, crack growth in the materials and material evaluation) under the working condition of power plants. We have evaluated lithium niobate (LiNbO3) single crystal which is well known as a high Curie temperature piezoelectric material to develop high temperature ultrasonic transducers. The LiNbO3 was bonded onto a stainless steel substrate. The experimental transducer was heated in an electric furnace while measuring the bottom echoes from the substrate. We confirmed that the experimental high temperature transducer could work up to 1000degC. Thermal and chemical stability of LiNbO3 were confirmed using TG measurement up to 1260degC (melting point). Additionally, we have developed single and array transducers for high temperature ultrasonic measurement based on those experimental data. (author)

  1. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  2. Ultrasonic comb transducer for smart materials

    Science.gov (United States)

    Rose, J. L.

    1998-04-01

    Installation of a small multi-element comb type ultrasonic transducer is proposed as a component of a smart structure. It can be used in either an active or passive mode in carrying out ultrasonic bulk or guided wave nondestructive evaluation. Theoretical methods are developed and experimental results are presented for guided wave generation and mode control with this very efficient and versatile novel comb type ultrasonic transducer. Excitation and probe design is crucial in mode selection. The comb transducer generates waves that are influenced by such parameters as number of elements, spacing between elements, dimension, pulsing sequence, and pressure distribution. The excited elastic field depends on the excitation frequency, plate thickness, and elastic properties. Techniques are studied to optimize the applied loading and the comb transducer design parameters so that only modes that are most sensitive to particular material characteristics can be generated. Complete understanding of the comb transducer parameters and their impact on the elastic field allows us to efficiently generate higher order modes as well as low phase velocity modes which are valuable in composite material characterization. Sample experiments are presented for various plate and tube like structures.

  3. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  4. High Temperature, High Power Piezoelectric Composite Transducers

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  5. Laser needle guide for the sonic flashlight.

    Science.gov (United States)

    Wang, David; Wu, Bing; Stetten, George

    2005-01-01

    We have extended the real-time tomographic reflection display of the Sonic Flashlight to a laser guidance system that aims to improve safety and accuracy of needle insertion, especially for deep procedures. This guidance system is fundamentally different from others currently available. Two low-intensity lasers are mounted on opposite sides of a needle aimed parallel to the needle. The needle is placed against a notch in the Sonic Flashlight mirror such that the laser beams reflect off the mirror to create bright red spots on the flat panel display. Due to diffuse reflection from these spots, the virtual image created by the flat panel display contains the spots, identifying the projected destination of the needle at its actual location in the tissue. We have implemented our design and validated its performance, identifying several areas for potential improvement. PMID:16685901

  6. Apical pressures developed by needles for canal irrigation.

    Science.gov (United States)

    Bradford, C E; Eleazer, P D; Downs, K E; Scheetz, J P

    2002-04-01

    Drying instrumented canals with pressurized air may result in patient morbidity or even fatality. Low pressure and side vent needles have been suggested to lessen the danger. This study observed apical pressures from different needles inserted deeply into small round and ovoid canals as instrumentation progressed. Low-pressure (5 psi) air was injected through the needles, and apical pressures were recorded after each instrument. Pressures varied greatly within each test group. Generalities that can be drawn are that binding the needle within the canal gives higher pressures than with the needle slightly short of binding and that pressures were higher with apexes instrumented to size 30 and higher. With the needle tightly bound, neither needle size, needle design, nor canal shape resulted in statistically significant mean pressure differences. With the needle slightly withdrawn, larger bore needles gave higher pressures than small diameter needles. Caution is advised with the clinical use of pressurized air in the drying of root canals. PMID:12043877

  7. Mechano-electric optoisolator transducer with hysteresis

    Science.gov (United States)

    Ciuruş, I. M.; Dimian, M.; Graur, A.

    2011-01-01

    This article presents a theoretical and experimental study of designing a mechano-electric optoisolator transducer with hysteresis. Our research is centred upon designing transducers on the basis of optical sensors, as photoelectric conversions eliminate the influence of electromagnetic disturbances. Conversion of the rotation/translation motions into electric signals is performed with the help of a LED-photoresistor Polaroid optocoupler. The driver of the optocoupler's transmitter module is an independent current source. The signal conditioning circuit is a Schmitt trigger circuit. The device is designed to be applied in the field of automation and mechatronics.

  8. Quantum limit in resonant vacuum tunneling transducers

    CERN Document Server

    Onofrio, Roberto

    2010-01-01

    We propose an electromechanical transducer based on a resonant-tunneling configuration that, with respect to the standard tunneling transducers, allows larger tunneling currents while using the same bias voltage. The increased current leads to an increase of the shot noise and an increase of the momentum noise which determine the quantum limit in the system under monitoring. Experiments with micromachined masses at 4.2 K could show dominance of the momentum noise over the Brownian noise, allowing observation of the quantum-mechanical noise at the mesoscopic scale.

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

    Directory of Open Access Journals (Sweden)

    Sabina Lim

    2010-01-01

    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.

  10. Effect of needle tract bleeding on occurrence of pneumothorax after transthoracic needle biopsy

    International Nuclear Information System (INIS)

    Purpose: Occasionally bleeding along the needle trajectory is observed at post-biopsy computed tomographic sections. This study was designed to evaluate the possible effect of needle tract bleeding on the occurrence of pneumothorax and on requirement of chest tube insertion. Materials and methods: Two hundred eighty-four needle biopsies performed in 275 patients in whom the needle traversed the aerated lung parenchyma were retrospectively reviewed. Bleeding along the needle tract, occurrence of pneumothorax and need for chest tube insertion, type and size of the needle, size of the lesion, length of the lung traversed by the needle, presence or absence of emphysema were noted. Effect of these factors on the rate of pneumothorax and needle-tract bleeding was evaluated. The data were analyzed by χ2 test. Results: Pneumothorax developed in 100 (35%) out of 284 procedures requiring chest tube placement in 16 (16%). Variables that were significantly associated with an increased risk of pneumothorax were depth of the lesion (P 0.05). However, analysis of the relation between length of lung traversed by the needle, tract-bleeding and pneumothorax rate indicated that tract-bleeding had a preventive effect on development of pneumothorax (P 0.05). Conclusion: Bleeding in the needle tract has a preventive effect on the occurrence of the pneumothorax in deep-seated lesions and in the presence of emphysema, although it does not affect the overall rate of pneumothorax

  11. A general digital linearising method for transducers

    NARCIS (Netherlands)

    Bolk, W.T.

    1985-01-01

    A practical three-point interpolation algorithm is presented which corrects for manufacturing tolerances, zero offset, scaling errors and nonlinearity of transducers and signal conditioners. The algorithm is applicable to data-acquisition systems which make use of a microprocessor. Each measuring ch

  12. Broadband, High-Temperature Ultrasonic Transducer

    Science.gov (United States)

    Parker, F. Raymond; Winfree, William P.; Barrows, Danny A.

    1995-01-01

    Materials chosen for endurance at high temperatures and acoustic coupling and damping. Acoustic transducer designed to exhibit broad frequency response and to survive temperatures close to melting points of brazing alloys. Attached directly and continuously to hot object monitored ultrasonically: for example, it can be attached to relatively cool spot on workpiece during brazing for taking ultrasonic quality-control measurements.

  13. Ferroelectret non-contact ultrasonic transducers

    Science.gov (United States)

    Bovtun, V.; Döring, J.; Bartusch, J.; Beck, U.; Erhard, A.; Yakymenko, Y.

    2007-09-01

    Dielectric and electromechanical properties of the cellular polypropylene ferroelectret films (EMFIT), combining strong piezoelectric response with a low density and softness, evidence their high potential for the air-coupled ultrasonic applications. The disadvantage of the low coupling factor is compensated by the extremely low acoustic impedance, which provides excellent matching to air and promises efficient sound transmission through the air transducer interface. The influence of the electrodes on the electromechanical properties was investigated. Electron beam evaporation technology was adapted to the EMFIT films, and films with both-sided Au and Al electrodes were prepared without reducing or suppressing of the electromechanical properties. Finally, prototype transducers based on the EMFIT films were developed. In spite of the simple construction and absence of matching layers, high sensitivity of the EMFIT transducers was proved in the air-coupled ultrasonic experiment. Amplitude and delay time scanned images of the polyethylene step wedge with holes, obtained in both pulse-echo and transmission modes, demonstrate that non-contact ultrasonic imaging and testing with EMFIT transducers is possible.

  14. Micromachined Ultrasonic Transducers for 3-D Imaging

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann

    Real-time ultrasound imaging is a widely used technique in medical diagnostics. Recently, ultrasound systems offering real-time imaging in 3-D has emerged. However, the high complexity of the transducer probes and the considerable increase in data to be processed compared to conventional 2-D ultr...

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

    International Nuclear Information System (INIS)

    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

  16. Pine needle abortion biomarker detected in bovine fetal fluids

    Science.gov (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...

  17. Amperometric biosensors based on carbon composite transducers

    Science.gov (United States)

    Lu, Fang

    1998-12-01

    Much current work in analytical chemistry is devoted to design of biosensors. One particular area in this field is the development of enzyme-based amperometric biosensors for the quantitative determination of a series of substrates in clinical, environmental, industrial and agricultural significance. This dissertation focuses on the design of improved amperometric biosensors based on carbon composite transducers. The use of metallized carbons as transducer materials results in remarkably selective amperometric biosensors. Such enzyme-based transducers eliminate major electroactive interferences, and hence circumvent the need for mediators or membrane barriers. The remarkable selectivity of metal-dispersed carbons is attributed to their strong, preferential, electrocatalytic capacity towards the reductive detection of biologically-generated hydrogen peroxide. Such electrocatalytic activity allows metal-dispersed biosensors to be operated at the optimal potential region between +0.1 and -0.2 V, where the unwanted reactions are neglected resulting in the lowest noise level. Several new materials (e.g., ruthenium on carbon, rhodium on carbon, etc.) and constructions (e.g., carbon fiber, electrochemical co-deposition transducer, etc.) were applied in the development of novel enzyme-based transducers in order to improve the selectivity and applicability of amperometric biosensors. The susceptibility of first-generation oxidase amperometric biosensing to oxygen fluctuations can be improved by using oxygen-rich fluorocarbons as the pasting binders in carbon paste enzyme transducers. Such binders provide an internal supply of oxygen resulting in efficient detection in oxygen-deficit conditions. In particular, the use of poly-chlorotrifluorethylene (Kel-F) oil as carbon paste binder results in a well-defined response and an identical signal up to 40 mM glucose in both the presence and absence of oxygen. Comparing with mediated or wired enzyme-based transducers, such internal

  18. Parameter sensitivity study of a Field II multilayer transducer model on a convex transducer

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2009-01-01

    A multilayer transducer model for predicting a transducer impulse response has in earlier works been developed and combined with the Field II software. This development was tested on current, voltage, and intensity measurements on piezoceramics discs (Bæk et al. IUS 2008) and a convex 128 element...... is a quantitative calibrated model for a complete ultrasound system. This includes a sensitivity study aspresented here.Statement of Contribution/MethodsThe study alters 35 different model parameters which describe a 128 element convex transducer from BK Medical Aps. The changes are within ±20 % of the values...... supplied by the manufacturer, which are considered the zero reference (ZR). Simulations of a system consisting of a transmit unit, a five material layer transducer, and the FIELD II predicted pressure are performed by altering in turn the value of a single parameter in steps of 2 %. The remaining...

  19. A Multi-Layered Needle Injection Simulator.

    Science.gov (United States)

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

    2016-01-01

    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.

  20. Biopsy needle detection in transrectal ultrasound.

    Science.gov (United States)

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

    2011-01-01

    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.

  1. Development of ultrasonic transducer for nondestructive testing of fruit

    International Nuclear Information System (INIS)

    In this study, the ultrasonic transducers for contact measurement of whole fruits were developed. The design parameters for ultrasonic transducer such as acoustical impedance of fruits, kinds of piezoelectric materials, ultrasonic wave frequency, and transducer diameter were investigated. In order to match the impedance between piezoelectric material and fruit, various wear plates were fabricated and evaluated. And to control the bandwidth of ultrasonic wave of the transducer, various backing materials were fabricated and evaluated. The wear plate of the transducer was specially designed and fabricated considering the curvature of fruit. Two kinds of transducers such as 100 kHz of central frequency with 40 mm of transducer diameter and 200 kHz of central frequency with 20 mm diameter were developed. Nondestructive evaluation of the fruit will be possible with the developed ultrasonic transducers.

  2. Mounting technique for pressure transducers minimizes measurement interferences

    Science.gov (United States)

    Lanham, R. N.; Taylor, C. E.; Balmer, C. E.; Hwang, C.

    1975-01-01

    Miniaturized transducers are fabricated from commercially available four-arm semiconductor gages; transducers are connected as bridge circuit and mounted on internal face of small diaphragm. Jacket made of conductive plastic may be needed to avoid buildup or static charges.

  3. Finite element model of needle electrode sensitivity

    Science.gov (United States)

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

    2010-04-01

    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.

  4. Needle Insertion with Duty-Cycled Rotation into Multiple Media

    OpenAIRE

    Lehocky, Craig A.; Riviere, Cameron N.

    2012-01-01

    Thin, flexible needles can be steered along nonlinear paths to reach deep anatomical structures within the human body. This study builds upon previous work involving steering of bevel-tipped needles by inserting while rotating in a duty-cycled fashion. Here we investigate how needle material and radius, duty cycle, and tissue stiffness affect needle curvature. Needles were inserted into media while rotated at a specified duty cycle and the curvature was measured. A linear relationship between...

  5. Dry needling versus acupuncture: the ongoing debate.

    Science.gov (United States)

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

    2015-12-01

    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. PMID:26546163

  6. Dry needling versus acupuncture: the ongoing debate.

    Science.gov (United States)

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

    2015-12-01

    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.

  7. Rational Tree Morphisms and Transducer Integer Sequences: Definition and Examples

    Science.gov (United States)

    ŠUnić, Zoran

    2007-04-01

    The notion of transducer integer sequences is considered through a series of examples (the chosen examples are related to the Tower of Hanoi problem on 3 pegs). By definition, transducer integer sequences are integer sequences produced, under a suitable interpretation, by finite transducers encoding rational tree morphisms (length and prefix preserving transformations of words that have only finitely many distinct sections).

  8. Ultrasonic transducer design for uniform insonation

    International Nuclear Information System (INIS)

    Techniques used in transducer development for acoustical imaging have been evaluated for the purpose of producing broad, uniform ultrasonic fields from planar radiators. Such fields should be useful in hyperthermia, physical therapy, and ultrasonic bioeffects studies. Fourier inversion of the circ function yielded a source velocity distribution proportional to (P/r) exp ((-ik/2Z) (2Z/sup 2/+r/sup 2/)) J/sub 1/(krP/Z), where r is the radial source coordinate, k is the wave number, and P is the desired radius of uniform insonation at a depth Z in water. This source distribution can be truncated without significantly degrading the solution. A simpler solution consists of exponentially shading the edge of an otherwise uniformly excited disk transducer. This approach was successfully approximated experimentally

  9. Orbital angular momentum-entanglement frequency transducer

    CERN Document Server

    Zhou, Zhi-Yuan; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Dong, Ming-Xin; Shi, Bao-Sen; Guo, Guang-Can

    2016-01-01

    Entanglement is a vital resource for realizing many tasks such as teleportation, secure key distribution, metrology and quantum computations. To effectively build entanglement between different quantum systems and share information between them, a frequency transducer to convert between quantum states of different wavelengths while retaining its quantum features is indispensable. Information encoded in the photons orbital angular momentum OAM degrees of freedom is preferred in harnessing the information carrying capacity of a single photon because of its unlimited dimensions. A quantum transducer, which operates at wavelengths from 1558.3 nm to 525 nm for OAM qubits, OAMpolarization hybrid entangled states, and OAM entangled states, is reported for the first time. Nonclassical properties and entanglements are demonstrated following the conversion process by performing quantum tomography, interference, and Bell inequality measurements. Our results demonstrate the capability to create an entanglement link betwe...

  10. Electromechanical transducer for acoustic telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas S. (Cedar Crest, NM)

    1993-01-01

    An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

  11. Electromechanical transducer for acoustic telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, D.S.

    1993-06-22

    An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

  12. Optomechanical transducers for quantum-information processing

    Energy Technology Data Exchange (ETDEWEB)

    Stannigel, K.; Zoller, P. [Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, A-6020 Innsbruck (Austria); Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria); Rabl, P. [Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, A-6020 Innsbruck (Austria); Soerensen, A. S. [QUANTOP, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen O (Denmark); Lukin, M. D. [Physics Department, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2011-10-15

    We discuss the implementation of optical quantum networks where the interface between stationary and photonic qubits is realized by optomechanical transducers [K. Stannigel et al., Phys. Rev. Lett. 105, 220501 (2010)]. This approach does not rely on the optical properties of the qubit and thereby enables optical quantum communication applications for a wide range of solid-state spin- and charge-based systems. We present an effective description of such networks for many qubits and give a derivation of a state transfer protocol for long-distance quantum communication. We also describe how to mediate local on-chip interactions by means of the optomechanical transducers that can be used for entangling gates. We finally discuss experimental systems for the realization of our proposal.

  13. A symmetrical low temperature pressure transducer

    Science.gov (United States)

    Helvensteijn, B. P. M.; VanSciver, S. W.

    1990-03-01

    The design and operating characteristics of a fully differential pressure transducer are described. The device is intended for use with He II heat transfer experiments where it operates in vacuum and at low temperatures (Tcapacitance change to an ac output voltage. The sensitivity is roughly 5 μV/Pa. For the present application, the capacitor and electronics have acceptable performance, with a mean noise level of ±5 Pa.

  14. Orbital angular momentum-entanglement frequency transducer

    OpenAIRE

    Zhou, Zhi-Yuan; Liu, Shi-Long; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Dong, Ming-xin; Shi, Bao-Sen; Guo, Guang-Can

    2016-01-01

    Entanglement is a vital resource for realizing many tasks such as teleportation, secure key distribution, metrology and quantum computations. To effectively build entanglement between different quantum systems and share information between them, a frequency transducer to convert between quantum states of different wavelengths while retaining its quantum features is indispensable. Information encoded in the photons orbital angular momentum OAM degrees of freedom is preferred in harnessing the ...

  15. Methods for segmenting curved needles in ultrasound images.

    Science.gov (United States)

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

    2006-06-01

    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.

  16. Language of Transducer Manipulation: Codifying Terms for Effective Teaching.

    Science.gov (United States)

    Bahner, David P; Blickendorf, J Matthew; Bockbrader, Marcia; Adkins, Eric; Vira, Amar; Boulger, Creagh; Panchal, Ashish R

    2016-01-01

    There is a need for consistent, repetitive, and reliable terminology to describe the basic manipulations of the ultrasound transducer. Previously, 5 basic transducer motions have been defined and used in education. However, even with this effort, there is still a lack of consistency and clarity in describing transducer manipulation and motion. In this technical innovation, we describe an expanded definition of transducer motions, which include movements to change the transducer's angle of insonation to the target as well as the location on the body to optimize the ultrasound image. This new terminology may allow for consistent teaching and improved communication in the process of image acquisition. PMID:26679204

  17. Language of Transducer Manipulation: Codifying Terms for Effective Teaching.

    Science.gov (United States)

    Bahner, David P; Blickendorf, J Matthew; Bockbrader, Marcia; Adkins, Eric; Vira, Amar; Boulger, Creagh; Panchal, Ashish R

    2016-01-01

    There is a need for consistent, repetitive, and reliable terminology to describe the basic manipulations of the ultrasound transducer. Previously, 5 basic transducer motions have been defined and used in education. However, even with this effort, there is still a lack of consistency and clarity in describing transducer manipulation and motion. In this technical innovation, we describe an expanded definition of transducer motions, which include movements to change the transducer's angle of insonation to the target as well as the location on the body to optimize the ultrasound image. This new terminology may allow for consistent teaching and improved communication in the process of image acquisition.

  18. Percutaneous needle aspiration biopsy of chest lesions: effectiveness when using an 18-gauge needle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Min; Jung, Gyoo Sik; Kim, So Sun; Huh, Jin Do; Joh, Young Duk; Huh, Bang [College of Medicine, Kosin National University, Busan (Korea, Republic of)

    1995-01-15

    Results of 181 percutaneous needle aspiration biopsies performed with an 18-gauge needle during a period of 3 years were analyzed to determine efficacy and safety of the procedure. Biposies were performed in patients that could not be diagnosed by bronchoscopy or sputum cytology. The biopsy procedure with 18-gauge Crown needle was guided by fluoroscopy. The biopsy specimen placed in 10% formalin solution were histologically confirmed. In 160 patients (89%), the positive diagnosis was made by percutaneous needle aspiration biopsy. There were 153 lung lesions (120 malignant and 33 benign lesions) and 7 mediastinal lesions. The diagnostic accuracy of malignant and benign disease was 91% and 80% respectively. Complications included pneumothorax (n = 11) and hemothorax (n = 1): six of them required treatment with chest tube and the remainder showed spontaneous resorption. PCNB with an 18-gauge needle provided a reliable, relatively safe diagnostic tool to establish the diagnosis of both malignant and benign chest lesions.

  19. Percutaneous needle aspiration biopsy of chest lesions: effectiveness when using an 18-gauge needle

    International Nuclear Information System (INIS)

    Results of 181 percutaneous needle aspiration biopsies performed with an 18-gauge needle during a period of 3 years were analyzed to determine efficacy and safety of the procedure. Biposies were performed in patients that could not be diagnosed by bronchoscopy or sputum cytology. The biopsy procedure with 18-gauge Crown needle was guided by fluoroscopy. The biopsy specimen placed in 10% formalin solution were histologically confirmed. In 160 patients (89%), the positive diagnosis was made by percutaneous needle aspiration biopsy. There were 153 lung lesions (120 malignant and 33 benign lesions) and 7 mediastinal lesions. The diagnostic accuracy of malignant and benign disease was 91% and 80% respectively. Complications included pneumothorax (n = 11) and hemothorax (n = 1): six of them required treatment with chest tube and the remainder showed spontaneous resorption. PCNB with an 18-gauge needle provided a reliable, relatively safe diagnostic tool to establish the diagnosis of both malignant and benign chest lesions

  20. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiu-Sheng [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Los Angeles, CA (United States); Benjauthrit, Vatcharee; Zhou, Qifa; Shung, K.K. [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); Wei, Qiang; Huang, Yuhong [Chemat Technology Inc., Northridge, CA (United States)

    2013-05-15

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 {mu}C/cm{sup 2} at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. (orig.)

  1. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    International Nuclear Information System (INIS)

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 μC/cm2 at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. (orig.)

  2. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K. Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 μC/cm2 at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications.

  3. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm(2) at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. PMID:23814408

  4. DIY guide-needle-assisted conjunctivodacryocystorhinostomy (CDCR).

    Science.gov (United States)

    Paik, Ji-Sun; Kim, Su-Ah; Doh, Sang-Hee

    2013-01-01

    In this study, we introduce DIY guide-needle-assisted conjunctivodacryocystorhinostomy (CDCR), in which a guide needle helps in measuring the initial Jones tube length for insertion and reduces unnecessary handling for tube changes. Three CDCR procedures were conducted in which the length of the Jones tube was calculated using a 22-gauge DIY guide needle, and a prospective study of tube position change and migration, (a major cause of CDCR failure) was done. Wound healing was almost complete within 4 weeks postoperatively in the osteotomy site, but in cases of partial middle turbinectomy, a little more time was necessary. There was a slight change in Jones tube position in the nasal cavity compared with the expected position of original tube tip, but no tube migration from the caruncle fixation position had occurred by the final follow-up time. This guide-needle-assisted CDCR has multiple advantages, such as easy measurement of the proper initial tube size, utilization of the initial needle path, and easy replacement of tubes. Finally, this approach to CDCR can be readily applied because it uses materials ordinarily found in hospitals to create the devices needed for the procedure, so there is no additional cost. PMID:22526574

  5. Medically relevant ElectroNeedle technology development.

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Carrie Frances; Thomas, Michael Loren; McClain, Jaime L.; Harper, Jason C.; Achyuthan, Komandoor E.; Ten Eyck, Gregory A.

    2008-11-01

    ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology.

  6. TREATMENT OF EPIGASTRIC PAIN WITH SUBCUTANEOUS NEEDLING

    Institute of Scientific and Technical Information of China (English)

    GUO Jia-tu

    2006-01-01

    @@ 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.

  7. Safety Issues for HIFU Transducer Design

    Science.gov (United States)

    Fleury, Gérard; Berriet, Rémi; Chapelon, Jean Yves; ter Haar, Gail; Lafon, Cyril; Le Baron, Olivier; Chupin, Laurent; Pichonnat, Fabrice; Lenormand, Jérôme

    2005-03-01

    In contrast with most ultrasound modalities for medical applications, (especially ultrasound imaging), High Intensity Focused Ultrasound (HIFU) involves technologies and procedures which may present risk to the patient. These risks, resulting from the high power levels required for effective therapy, should be taken into account at the earliest stages in the design of a system dedicated to HIFU treatment. An understanding of these risks must thus be shared amongst the many players in the field of therapy using high power ultrasound. Moreover, since the number of applications of HIFU has increased appreciably over recent years and the technology is ready to move from the research to the industrial level, it is worth now considering solutions that should be put in place to guarantee the safety of the patient during HIFU treatment. This paper reports thoughts on this, identifies some risks to the patient that must be taken into consideration in the design of HIFU transducers, and proposes some solutions that could prevent the deleterious consequences of transducer misuse or failure. For the main risks identified, such as exceeding the desired acoustic power or poor control of tissue targeting, a description of transducer performance that could potentially result in problems is systematically sought. This allows proposals for precautions to be taken during operation to be made. Parameters which should be monitored to ensure safe use are also suggested. This type of approach, which should be undertaken for the different components of a therapeutic system, highlights the challenges that must be faced in the immediate future for the development and safe exploitation of HIFU systems. The necessity for standard definitions of the parameters to be checked or monitored during HIFU treatments is crucial in this approach, as is the availability of reliable dedicated measurement devices. Co-ordinated action on these topics in the HIFU community would contribute to the

  8. A high-temperature wideband pressure transducer

    Science.gov (United States)

    Zuckerwar, A. J.

    1975-01-01

    Progress in the development of a pressure transducer for measurement of the pressure fluctuations in the high temperature environment of a jet exhaust is reported. A condenser microphone carrier system was adapted to meet the specifications. A theoretical analysis is presented which describes the operation of the condenser microphone in terms of geometry, materials, and other physical properties. The analysis was used as the basis for design of a prototype high temperature microphone. The feasibility of connecting the microphone to a converter over a high temperature cable operating as a half-wavelength transmission line was also examined.

  9. Electromechanically active polymer transducers: research in Europe

    DEFF Research Database (Denmark)

    Carpi, Federico; Graz, Ingrid; Jager, Edwin;

    2013-01-01

    in two major families: ionic EAPs (activated by an electrically induced transport of ions and/or solvent) and electronic EAPs (activated by electrostatic forces). These polymers show interesting properties, such as sizable active strains and/or stresses in response to electrical driving, high mechanical...... flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise and, in most cases, low costs. Since many of these characteristics can also describe natural muscle tissues from an engineering standpoint, it is not surprising that EAP transducers are sometimes also...

  10. The Needling Technique and Clinical Application of Point Zhibian

    Institute of Scientific and Technical Information of China (English)

    张远东

    2004-01-01

    @@ 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.

  11. A double-blind placebo needle for acupuncture research

    Directory of Open Access Journals (Sweden)

    Takakura Nobuari

    2007-10-01

    Full Text Available Abstract Background Placebo needles that can mask acupuncture practitioners to the type of needle used have been considered almost impossible to develop until now. Methods We designed a double-blind non-penetrating placebo needle, the needle tip of which simply presses against the skin, and a matched penetrating needle. The needles are encased inside an opaque guide tube and the appearance and feel of the pair are designed to be indistinguishable. To validate the masking effect for the practitioner, 10 acupuncturists each applied 23 non-penetrating needles and 17 penetrating needles to the Large Intestine-4 point. After removing each needle, they judged whether the needle was 'penetrating', 'non-penetrating' or 'unidentifiable'. For the validation of patient masking, an acupuncturist randomly applied a non-penetrating/penetrating needle pair to the bilateral Sanjiao-5 points in 60 volunteers. When both applications were completed, we asked them to write down anything that they noticed regarding the needle application and associated sensations. Results The mean ± SD of correct/unidentifiable/incorrect answers given by the 10 acupuncturists were 17.0 ± 4.1/6.4 ± 3.6/16.6 ± 3.0, respectively. Regarding patient masking, none of the subjects commented in the questionnaire that they had received a non-penetrating needle. Of 60 penetrating and 60 non-penetrating needle applications, 48 (80.0% and 25 (41.7% applications elicited skin penetration sensation and 48 (80.0% and 20 (33.3% applications elicited de qi, respectively. Conclusion These needles have the potential to mask both practitioners and patients from the type of needle used in acupuncture research.

  12. Embedded ultrasonic transducers for active and passive concrete monitoring.

    Science.gov (United States)

    Niederleithinger, Ernst; Wolf, Julia; Mielentz, Frank; Wiggenhauser, Herbert; Pirskawetz, Stephan

    2015-01-01

    Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer's axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences. PMID:25923928

  13. Using FOCUS to determine the radiation impedance for square transducers

    Science.gov (United States)

    Jennings, Matthew R.; McGough, Robert J.

    2012-10-01

    The power radiated by an ultrasound transducer is calculated with the radiation resistance, which is the real part of the radiation impedance. For circular transducers, an analytical solution for the radiation impedance is known, but an analytical expression for the radiation impedance is not available for rectangular or square transducers. To determine the radiation resistance in FOCUS, the pressure on the surface of a square transducer is computed with the fast nearfield method, and then the force on the transducer face is computed by integrating the pressure. Results using this approach are numerically evaluated for a range of ka values from 0.1 to 16. The pressure on the transducer face is also computed with the Rayleigh-Sommerfeld integral, and the results are compared. The numerical value of the radiation resistance computed with FOCUS and with the Rayleigh-Sommerfeld integral converge to the same value, although FOCUS calculates the same result in about one-quarter of the time.

  14. Polyvinylidene fluoride - a polymer as transducer material

    International Nuclear Information System (INIS)

    Polyvinylidene fluoride or PVDF is a flexible, thin piezo film and long chain semicrystalline polymer containing repeated of CH/sub 2/ - CH/sub 2/. In order to obtain desired piezoelectric properties PVDF is poled by subjecting it to high electric field. In poled PVDF piezoelectric constants have different values for each axis and one constant per axis. PVDF polymer exhibits generator and motor action. Usually 1000 A /sup o/ thick vacuum-deposited aluminum electrodes are formed on both sides of the sheet. Polymer material of PVDF can be used as a sensing element with temperature range of -40 /sup 0/ C to 100 /sup 0/C and a frequency range of 10/sup -3/ to 10/sup -9/ Hz. This paper includes as experimental observation of exciting aluminium open-ended tube at its resonance using PVDF transducer and maintained in this condition using phase lock loop or PLL. The tube is free to resonate when 9-micrometer thin polyvinylidene fluoride transducer is energized. It is observed that a film of such material can easily be used to produced the requisite vibrations in the tube. (author)

  15. Biomolecular detection with a thin membrane transducer.

    Science.gov (United States)

    Cha, Misun; Shin, Jaeha; Kim, June-Hyung; Kim, Ilchaek; Choi, Junbo; Lee, Nahum; Kim, Byung-Gee; Lee, Junghoon

    2008-06-01

    We present a thin membrane transducer (TMT) that can detect nucleic acid based biomolecular reactions including DNA hybridization and protein recognition by aptamers. Specific molecular interactions on an extremely thin and flexible membrane surface cause the deflection of the membrane due to surface stress change which can be measured by a compact capacitive circuit. A gold-coated thin PDMS membrane assembled with metal patterned glass substrate is used to realize the capacitive detection. It is demonstrated that perfect match and mismatch hybridizations can be sharply discriminated with a 16-mer DNA oligonucleotide immobilized on the gold-coated surface. While the mismatched sample caused little capacitance change, the perfectly matched sample caused a well-defined capacitance decrease vs. time due to an upward deformation of the membrane by a compressive surface stress. Additionally, the TMT demonstrated the single nucleotide polymorphism (SNP) capabilities which enabled a detection of mismatching base pairs in the middle of the sequence. It is intriguing that the increase of capacitance, therefore a downward deflection due to tensile stress, was observed with the internal double mismatch hybridization. We further present the detection of thrombin protein through ligand-receptor type recognition with 15-mer thrombin aptamer as a receptor. Key aspects of this detection such as the effect of concentration variation are investigated. This capacitive thin membrane transducer presents a completely new approach for detecting biomolecular reactions with high sensitivity and specificity without molecular labelling and optical measurement. PMID:18497914

  16. Orbital Angular Momentum-Entanglement Frequency Transducer

    Science.gov (United States)

    Zhou, Zhi-Yuan; Liu, Shi-Long; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Dong, Ming-Xin; Shi, Bao-Sen; Guo, Guang-Can

    2016-09-01

    Entanglement is a vital resource for realizing many tasks such as teleportation, secure key distribution, metrology, and quantum computations. To effectively build entanglement between different quantum systems and share information between them, a frequency transducer to convert between quantum states of different wavelengths while retaining its quantum features is indispensable. Information encoded in the photon's orbital angular momentum (OAM) degrees of freedom is preferred in harnessing the information-carrying capacity of a single photon because of its unlimited dimensions. A quantum transducer, which operates at wavelengths from 1558.3 to 525 nm for OAM qubits, OAM-polarization hybrid-entangled states, and OAM-entangled states, is reported for the first time. Nonclassical properties and entanglements are demonstrated following the conversion process by performing quantum tomography, interference, and Bell inequality measurements. Our results demonstrate the capability to create an entanglement link between different quantum systems operating in a photon's OAM degrees of freedom, which will be of great importance in building a high-capacity OAM quantum network.

  17. Instantaneous crack detection using dual PZT transducers

    Science.gov (United States)

    Kim, Seung Bum; Sohn, Hoon

    2008-03-01

    A new guided wave based nondestructive testing (NDT) technique is developed to detect crack damage in metallic plates commonly used in aircraft without using prior baseline data or a predetermined decision boundary. In conventional guided wave based techniques, damage is often identified by comparing the "current" data obtained from a potentially damaged condition of a structure with the "past" baseline data collected at the pristine condition of the structure. However, it has been reported that this type of pattern comparison with the baseline data can lead to increased false alarms due to its susceptibility to varying operational and environmental conditions of the structure. In order to tackle this issue, a reference-free damage detection technique is previously developed using two pairs of collocated lead zirconate titanate transducers (PZTs) placed on both sides of a plate. In this study, this reference-free technique is further advanced so that the PZT transducers can be placed only on one side of the specimen. Crack formation creates Lamb wave mode conversion due to a sudden change in the thickness of the structure. Then, the proposed technique instantly detects the appearance of the crack by extracting this mode conversion from the measured Lamb waves. This study suggests a reference-free statistical approach that enables damage classification using only the current data set. Numerical and experimental results are presented to demonstrate the applicability of the proposed technique to instantaneous crack detection.

  18. Hollow needle used to cut metal honeycomb structures

    Science.gov (United States)

    Gregg, E. A.

    1966-01-01

    Hollow needle tool cuts metal honeycomb structures without damaging adjacent material. The hollow needle combines an electrostatic discharge and a stream of oxygen at a common point to effect rapid, accurate metal cutting. The tool design can be varied to use the hollow needle principle for cutting a variety of shapes.

  19. Comparative Study of Wear Resistance of Sewing Needles

    Institute of Scientific and Technical Information of China (English)

    FEI Dong-ye; ZHU Shi-gen

    2002-01-01

    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.

  20. 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.

    2010-01-01

    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

  1. Embedded Ultrasonic Transducers for Active and Passive Concrete Monitoring

    OpenAIRE

    Ernst Niederleithinger; Julia Wolf; Frank Mielentz; Herbert Wiggenhauser; Stephan Pirskawetz

    2015-01-01

    Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequen...

  2. Highly reproducible Bragg grating acousto-ultrasonic contact transducers

    Science.gov (United States)

    Saxena, Indu Fiesler; Guzman, Narciso; Lieberman, Robert A.

    2014-09-01

    Fiber optic acousto-ultrasonic transducers offer numerous applications as embedded sensors for impact and damage detection in industrial and aerospace applications as well as non-destructive evaluation. Superficial contact transducers with a sheet of fiber optic Bragg gratings has been demonstrated for guided wave ultrasound based measurements. It is reported here that this method of measurement provides highly reproducible guided ultrasound data of the test composite component, despite the optical fiber transducers not being permanently embedded in it.

  3. Long-Term Stability of the NIST Conical Reference Transducer

    OpenAIRE

    Fick, Steven E.; Proctor, Thomas M.

    2011-01-01

    The National Institute of Standards and Technology (NIST) Conical Reference Transducer (CRT) is designed for purposes requiring frequency response characteristics much more uniform than those attainable with ultrasonic transducers conventionally used for acoustic emission (AE) nondestructive testing. The high performance of the CRT results from the use of design elements radically different from those of conventional transducers. The CRT was offered for sale for 15 years (1985 to 2000). Each ...

  4. Can elastography replace fine needle aspiration?

    DEFF Research Database (Denmark)

    Popescu, Alexandru; Săftoiu, Adrian

    2014-01-01

    Endoscopic ultrasound (EUS) is one of the best diagnostic methods for diseases of the digestive tract and surrounding organs. Whereas EUS-guided fine needle aspiration (FNA) has been very useful for providing histological confirmation for previously hard to reach lesions, elastography is aiming...

  5. Relationship between needle phobia and dental anxiety

    NARCIS (Netherlands)

    M. Majstorovic; J.S.J. Veerkamp

    2004-01-01

    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

  6. Thin needle aspiration biopsy of endocrine organs.

    Science.gov (United States)

    Koss, L G

    1979-01-01

    The purpose of this paper is to summarize the advantages and disadvantages of the fine needle aspiration technique in reference to the endocrine organs. The principles of technique and interpretation are presented. The application of aspiration biopsies to the breast, the prostate, the pancreas and the thyroid are briefly discussed. PMID:485094

  7. The Single Needle Lockstitch Machine. Module 1.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on parts of the machine, one in a series on the single needle lockstitch sewing machine for student self-study, contains eight sections. Each section contains the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final…

  8. Buffon Needle Problem Application to Space Exploration

    CERN Document Server

    Sedelnikov, A V

    2010-01-01

    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.

  9. Particulate contamination of sterile syringes and needles.

    Science.gov (United States)

    Taylor, S A

    1982-08-01

    Commercially available sterile needles and syringes have been examined for particulate contamination using the Hiac light blockage technique. The number of particles delivered was small compared with the total number permitted for large volume parenterals. Where syringes are used in particle counting techniques, the contribution of particles should be taken into account. PMID:6126558

  10. Needle core biopsy for breast lesions: An audit of 467 needle core biopsies

    OpenAIRE

    Selvi Radhakrishna; Anu Gayathri; Deepa Chegu

    2013-01-01

    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...

  11. Modeling of multilayered piezoelectric transducers with ultrasonic welding application

    Science.gov (United States)

    Güney, Murat; Eskinat, Esref

    2007-04-01

    Mechanical components of sandwiched piezoelectric transducers are modeled using one-dimensional wave transmission and piezoelectric equations. Using the impedance method, resonance frequencies, stress and displacement distributions along the multilayered piezoelectric transducers of different dimensions and materials are obtained. The calculated resonance frequencies and the impedances are experimentally verified. For ultrasonic welding of plastics, the effect of the parts to be welded on the resonance frequency of the whole system is investigated regarding both material damping and piezoelectric losses. Using the methods developed, several piezoelectric transducers are analysed for different designs. The obtained results can be used to better understand the qualitative relations between the design variables of ultrasonic piezoelectric transducers.

  12. Radiation endurance of piezoelectric ultrasonic transducers--a review.

    Science.gov (United States)

    Sinclair, A N; Chertov, A M

    2015-03-01

    A literature survey is presented on the radiation endurance of piezoelectric ultrasonic transducer components and complete transducer assemblies, as functions of cumulative gamma dose and neutron fluence. The most extensive data on this topic has been acquired in CANDU electrical generating stations, which use piezoelectric ultrasonic transducers manufactured commercially with minor accommodation for high radiation fields. They have been found to be reliable for cumulative gamma doses of up to approximately 2 MegaGrays; a brief summary is made of the associated accommodations required to the transducer design, and the ultimate expected failure modes. Outside of the CANDU experience, endurance data have been acquired under a diverse spectrum of operating conditions; this can impede a direct comparison of the information from different sources. Much of this data is associated with transducers immersed in liquid metal coolants associated with advanced reactor designs. Significant modifications to conventional designs have led to the availability of custom transducers that can endure well over 100 MegaGrays of cumulative gamma dose. Published data on transducer endurance against neutron fluence are reviewed, but are either insufficient, or were reported with inadequate description of test conditions, to make general conclusions on transducer endurance with high confidence. Several test projects are planned or are already underway by major laboratories and research consortia to augment the store of transducer endurance data with respect to both gamma and neutron radiation.

  13. High Temperature Ultrasonic Transducer for Real-time Inspection

    Science.gov (United States)

    Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

    A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

  14. Method and results of studying conduction measuring transducers

    Energy Technology Data Exchange (ETDEWEB)

    Dunaevskii, I.G.; Korotkov, B.N.; Povkh, I.L.; Cheplyukov, V.G.

    1977-01-01

    The method and results are given for determining the sensitivity of conduction measuring transducers with a local magnetic field. The results were obtained by frequency-dependent gradation on a model pulsation velocity gauge--a thermoanemometer. The effect of measuring a transducer's diameter, inter-electrode distance and nose line forms on its spatial resolution capacity was estimated. Adjustment functions were obtained for these transducers. A concept was formulated for measuring transducers belonging to the same class. 5 references, 5 figures.

  15. Monitoring Method for the Electrical Properties of Piezoelectric Transducer

    Institute of Scientific and Technical Information of China (English)

    李文; 朱泽琪

    2012-01-01

    The monitoring of cutting force in a vibration cutting process has a great significance in the popularization of ultrasonic vibration cutting technology. A new monitoring method of which the cutting force of ultrasonic elliptic vibration cutting is monitored using the electrical properties of transducer was proposed by studying on the relationship of cutting force, transducer electric impedance and load. A measurement system was designed for the electrical properties of transducer. The feasibility of cutting force monitoring method based on the electrical properties of piezoelectric transducer was proved by the cutting experiments.

  16. Evaluation of several ultrasonic flowmeter transducers in cryogenic environment

    Science.gov (United States)

    Moughon, W. C.

    1981-04-01

    Eighteen piezoelectric ultrasonic flowmeter transducers were laboratory tested to determine their suitability and long range reliability for use by the National Transonic Facility (NTF) to measure the flow rate of 450 Kg/sec of liquid nitrogen (LN2). Tests included thermally cycling each transducer 50 to 150 times over a temperature range of 295 K (ambient) to 77 K (LN2). The transducers were submerged in liquid nitrogen for 1 to 4 hours and the signal strength and quality noted. Results disclose that the current state-of-the-art ultrasonic flow transducers are very reliable and will meet the stringent requirements of the NTF.

  17. The research of knitting needle status monitoring setup

    Science.gov (United States)

    Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie

    2013-09-01

    In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.

  18. Accuracy of needle position measurements using fiber Bragg gratings.

    Science.gov (United States)

    Henken, Kirsten; Van Gerwen, Dennis; Dankelman, Jenny; Van Den Dobbelsteen, John

    2012-11-01

    Accurate placement of the needle tip is essential in percutaneous therapies such as radiofrequency ablation (RFA) of liver tumors. Use of a robotic system for navigating the needle could improve the targeting accuracy. Real-time information on the needle tip position is needed, since a needle deflects during insertion in tissue. Needle shape can be reconstructed based on strain measurements within the needle. In the current experiment we determined the accuracy with which the needle tip position can be derived from strain measurements using Fiber Bragg Gratings (FBGs). Three glass fibers equipped with two FBGs each were incorporated in a needle. The needle was clamped at one end and deformed by applying static radial displacements at one or two locations. The FBG output was used for offline estimation of the needle shape and tip position. During deflections of the needle tip up to 12.5 mm, the tip position was estimated with a mean accuracy of 0.89 mm (std 0.42 mm). Adding a second deflection resulted in an error of 1.32 mm (std 0.48 mm). This accuracy is appropriate for applications such as RFA of liver tumors. The results further show that the accuracy can be improved by optimizing the placement of FBGs. PMID:22455615

  19. Linear ultrasonic motor using quadrate plate transducer

    Institute of Scientific and Technical Information of China (English)

    Jiamei JIN; Chunsheng ZHAO

    2009-01-01

    A linear ultrasonic motor using a quadrate plate transducer was developed for precision positioning. This motor consists of two pairs of Pb(Zr, Ti)O3 piezo-electric ceramic elements, which are piezoelectrically excited into the second-bending mode of the motor stator's neutral surface in two orthogonal directions, on which the tops of four projections move along an elliptical trajectory, which in turn drives a contacted slider into linear motion via frictional forces. The coincident frequency of the stator is easily obtained for its coincident characteristic dimen-sion in two orthogonal directions. The performance characteristics achieved by the motor are: 1) a maximum linear speed of more than 60 mm/s; 2) a stroke of more than 150 mm; 3) a driving force of more than 5.0 N; and 4) a response time of about 2 ms.

  20. Magnetoelastic Transducer Materials - a Plateable Possibility

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl; Møller, Per

    2001-01-01

    A short presentation of the magnetostriction theory as well as a series of possible applications for magnetoelastic transducers are given. A review of the present state of development for these materials is discussed with relation to the various ways of manufacture. The paper is concluded...... as the reference material Terfenol-D were obtained, but reproduction of exact magnetic properties is still critical with the new plating technique....... with the presentation of a method for making magnetoelastic materials by electrochemical deposition (electroless) as tried by the authors in collaboration with the Daimler-Chrysler research centre in Ulm, Germany. First results of this work are both promising and intriguing: Sensitivities of the same order...

  1. Development of piezoelectric composites for transducers

    Science.gov (United States)

    Safari, A.

    1994-07-01

    For the past decade and a half, many different types of piezoelectric ceramic-polymer composites have been developed intended for transducer applications. These diphasic composites are prepared from non-active polymer, such as epoxy, and piezoelectric ceramic, such as PZT, in the form of filler powders, elongated fibers, multilayer and more complex three-dimensional structures. For the last four years, most of the efforts have been given to producing large area and fine scale PZT fiber composites. In this paper, processing of piezoelectric ceramic-polymer composites with various connectivity patterns are reviewed. Development of fine scale piezoelectric composites by lost mold, injection molding and the relic method are described. Research activities of different groups for preparing large area piezocomposites for hydrophone and actuator applications are briefly reviewed. Initial development of electrostrictive ceramics and composites are also

  2. NUTRIENTS CONCENTRATION AND RETRANSLOCATION IN THE Pinus taeda L. NEEDLES

    Directory of Open Access Journals (Sweden)

    Márcio Viera

    2010-03-01

    Full Text Available Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West, sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients. The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.

  3. Multilayer Array Transducer for Nonlinear Ultrasound Imaging

    Science.gov (United States)

    Owen, Neil R.; Kaczkowski, Peter J.; Li, Tong; Gross, Dan; Postlewait, Steven M.; Curra, Francesco P.

    2011-09-01

    The properties of nonlinear acoustic wave propagation are known to be able to improve the resolution of ultrasound imaging, and could be used to dynamically estimate the physical properties of tissue. However, transducers capable of launching a wave that becomes nonlinear through propagation do not typically have the necessary bandwidth to detect the higher harmonics. Here we present the design and characterization of a novel multilayer transducer for high intensity transmit and broadband receive. The transmit layer was made from a narrow-band, high-power piezoceramic (PZT), with nominal frequency of 2.0 MHz, that was diced into an array of 32 elements. Each element was 0.300 mm wide and 6.3 mm in elevation, and with a pitch of 0.400 mm the overall aperture width was 12.7 mm. A quarter-wave matching layer was attached to the PZT substrate to improve transmit efficiency and bandwidth. The overlaid receive layer was made from polyvinylidene fluoride (PVDF) that had gold metalization on one side. A custom two-sided flex circuit routed electrical connections to the PZT elements and patterned the PVDF elements; the PZT and PVDF elements had identical apertures. A low viscosity and electrically nonconductive epoxy was used for all adhesion layers. Characterization of electrical parameters and acoustic output were performed per standard methods, where transmit and receive events were driven by a software-controlled ultrasound engine. Echo data, collected from ex vivo tissue and digitized at 45 MS/s, exhibited frequency content up to the 4th harmonic of the 2 MHz transmit frequency.

  4. [Cytologic diagnosis of abdominal lesions with fine needle aspiration guided by ultrasound].

    Science.gov (United States)

    Candia, P; Rojas, M; Alvarado, M; Garassini, M A; Römer, M A

    1990-01-01

    The purpose of this work was to analyse the advantages and disadvantages of puncture-aspiration with fine needle, guided by ultrasonography, trying to determine its usefulness in our hospitals and its reliability in the diagnosis of intraabdominal lesions of different locations. 29 punctures were practiced on 19 patients, 9 women and 10 men of ages comprised between 34 and 94 years, with lesions in different organs of the abdominal cavity diagnosed by ultrasonography with real time equipment and lineal 3.5 and 5 MHz transducers. After cleaning and antisepsis a Chiba needle is introduced under ultrasonographic vision, up to the location of the lesion, the guide is removed and under a negative pressure, the sample is taken, which is later dried into the air and coloured using the May-Grünwald-Giemsa Technique. Only in one case it was not possible to obtain adequate material for the cytological study. There were 11 positive cases for malignity and 7 negative, one of which was a false negative. The sensibility of the method was of 91.6% with a specificity of 100% and a reliability of 89.4%. We definitely believe that the method is practical, very easy to carry out in our hospitals with a minimum amount of risk, and most of all, dependable to clarify certain diagnoses. PMID:2152268

  5. 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

    2013-01-01

    Full Text Available Objective. To explore the existing scientific information regarding safe needling depth of acupuncture points and the needling depth of clinical efficacy. Methods. We searched the PubMed, EMBASE, Cochrane, Allied and Complementary Medicine (AMED, The National Center for Complementary and Alternative Medicine (NCCAM, and China National Knowledge Infrastructure (CNKI databases to identify relevant monographs and related references from 1991 to 2013. Chinese journals and theses/dissertations were hand searched. Results. 47 studies were recruited and divided into 6 groups by measuring tools, that is, MRI, in vivo evaluation, CT, ultrasound, dissected specimen of cadavers, and another group with clinical efficacy. Each research was analyzed for study design, definition of safe depth, and factors that would affect the measured depths. Depths of clinical efficacy were discussed from the perspective of de-qi and other clinical observations. Conclusions. Great inconsistency in depth of each point measured from different subject groups and tools exists. The definition of safe depth should be established through standardization. There is also lack of researches to compare the clinical efficacy. A well-designed clinical trial selecting proper measuring tools to decide the actual and advisable needling depth for each point, to avoid adverse effects or complications and promote optimal clinical efficacy, is a top priority.

  6. AXIAL DEFFLECTION STUDIES OF RING SHAPED FORCE TRANSDUCER: A REVIEW

    Directory of Open Access Journals (Sweden)

    SUDHIR KUMAR,

    2011-01-01

    Full Text Available The ring shaped force transducers are widely used in practice and are available in varying capacities from few hundred newtons to mega newtons. The present paper discusses the deflection studies of thering shaped force transducers under action of axial forces. Various methods leading to the measurement of deflection have been discussed and compared here.

  7. Quality assurance with measuring transducers through EMP planning

    International Nuclear Information System (INIS)

    Measuring transducers in industrial application are subjected to various interferences. These are discussed as well as possible protection measures. The described measuring transducers are of modular design. Thus in individual cases it is possible to prevent the interference there where it occurs through special interference protection modules. The required measuring means for the testing of the EMP are introduced. (orig.)

  8. Metal cap flexural transducers for air-coupled ultrasonics

    Science.gov (United States)

    Eriksson, T. J. R.; Dixon, S.; Ramadas, S. N.

    2015-03-01

    Ultrasonic generation and detection in fluids is inefficient due to the large difference in acoustic impedance between the piezoelectric element and the propagation medium, leading to large internal reflections and energy loss. One way of addressing the problem is to use a flexural transducer, which uses the bending modes in a thin plate or membrane. As the plate bends, it displaces the medium in front of it, hence producing sound waves. A piezoelectric flexural transducer can generate large amplitude displacements in fluid media for relatively low excitation voltages. Commercially available flexural transducers for air applications operate at 40 kHz, but there exists ultrasound applications that require significantly higher frequencies, e.g. flow measurements. Relatively little work has been done to date to understand the underlying physics of the flexural transducer, and hence how to design it to have specific properties suitable for particular applications. This paper investigates the potential of the flexural transducer and its operating principles. Two types of actuation methods are considerd: piezoelectric and electrodynamic. The piezoelectrically actuated transducer is more energy efficient and intrinsically safe, but the electrodynamic transducer has the advantage of being less sensitive to high temperature environments. The theory of vibrating plates is used to predict transducer frequency in addition to front face amplitude, which shows good correlation with experimental results.

  9. Thermal dispersion method for an ultrasonic phased-array transducer

    Science.gov (United States)

    Choi, Euna; Lee, Wonseok; Roh, Yongrae

    2016-07-01

    When the driving voltage of an ultrasonic transducer is increased to improve the quality of ultrasound images, heat is generated inside the transducer, which can burn the patient’s skin and degrade transducer performance. In this study, the method to disperse the heat inside an ultrasonic phased-array transducer has been examined. The mechanism of temperature rise due to heat generation inside the transducer was investigated by numerical analysis and the effects of the thermal properties of the components of the transducer such as specific heat and thermal conductivity on the temperature rise were analyzed. On the basis of the results, a heat-dispersive structure was devised to reduce the temperature at the surface of the acoustic lens of the transducer. Prototype transducers were fabricated to check the efficacy of the heat-dispersive structure. By experiments, we have confirmed that the new heat-dispersive structure can reduce the internal temperature by as much as 50% in comparison with the conventional structure, which confirms the validity of the thermal dispersion mechanism developed in this work.

  10. Broadband tonpilz underwater acoustic transducers based on multimode optimization

    DEFF Research Database (Denmark)

    Yao, Qingshan; Jensen, Leif Bjørnø

    1997-01-01

    Head flapping has often been considered to be deleterious for obtaining a tonpilz transducer with broadband, high power performance. In the present work, broadband, high power tonpilz transducers have been designed using the finite element (FE) method. Optimized vibrational modes including the fl...

  11. A Force Transducer from a Junk Electronic Balance

    Science.gov (United States)

    Aguilar, Horacio Munguia; Aguilar, Francisco Armenta

    2009-01-01

    It is shown how the load cell from a junk electronic balance can be used as a force transducer for physics experiments. Recovering this device is not only an inexpensive way of getting a valuable laboratory tool but also very useful didactic work on electronic instrumentation. Some experiments on mechanics with this transducer are possible after a…

  12. Micro-stereolithography as a transducer design method.

    Science.gov (United States)

    Ho, K S; Bradley, R J; Billson, D R; Hutchins, D A

    2008-03-01

    This paper investigates the use of micro-stereolithography, a rapid prototyping technique, in the manufacture of transducers. It is illustrated for the production of electromagnetic acoustic transducer (EMATs) coils in both meander-line and spiral configurations. A synthetic aperture focussing technique (SAFT) has been applied to the ultrasonic signals from these devices to reconstruct images in metallic objects.

  13. Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia.

    Science.gov (United States)

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

    2006-07-01

    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.

  14. Embedded Ultrasonic Transducers for Active and Passive Concrete Monitoring

    Directory of Open Access Journals (Sweden)

    Ernst Niederleithinger

    2015-04-01

    Full Text Available Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer’s axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, … as well as damages in an early state or the detection of acoustic events (e.g., crack opening. Besides application in civil engineering our setups can also be used for model studies in geosciences.

  15. Embedded Ultrasonic Transducers for Active and Passive Concrete Monitoring

    Science.gov (United States)

    Niederleithinger, Ernst; Wolf, Julia; Mielentz, Frank; Wiggenhauser, Herbert; Pirskawetz, Stephan

    2015-01-01

    Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer’s axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences. PMID:25923928

  16. Flexible ultrasonic array transducer for thickness measurement of curved pipes

    International Nuclear Information System (INIS)

    The feeder pipes in a Pressurized Heavy Water Reactor (PHWR) has a very complicated form with bent pipes. In this study, we have fabricated the Polyvinylidene fluoride (PVDF) array transducer to meet the dimension requirement passing smoothly along the pipe and have evaluated the signals in order to increase the accuracy of measurement. A contact array transducer was fabricated using commercially available PVDF film samples. Each pulse echo signals were acquired and analyzed using the pulser/receiver, The array transducer was demonstrated to show a serviceable performance as a contact transducer. Pulse echo reflections from a back-wall of feeder pipe were shown as a typical wideband signal. Ultrasonic signals were analyzed by considering the center frequency, band width and waveform. PVDF array transducer for thickness measurement can be applied to monitor the integrity of feeder pipes in PHWR.

  17. Piezoelectric single crystals for ultrasonic transducers in biomedical applications.

    Science.gov (United States)

    Zhou, Qifa; Lam, Kwok Ho; Zheng, Hairong; Qiu, Weibao; Shung, K Kirk

    2014-10-01

    Piezoelectric single crystals, which have excellent piezoelectric properties, have extensively been employed for various sensors and actuators applications. In this paper, the state-of-art in piezoelectric single crystals for ultrasonic transducer applications is reviewed. Firstly, the basic principles and design considerations of piezoelectric ultrasonic transducers will be addressed. Then, the popular piezoelectric single crystals used for ultrasonic transducer applications, including LiNbO3 (LN), PMN-PT and PIN-PMN-PT, will be introduced. After describing the preparation and performance of the single crystals, the recent development of both the single-element and array transducers fabricated using the single crystals will be presented. Finally, various biomedical applications including eye imaging, intravascular imaging, blood flow measurement, photoacoustic imaging, and microbeam applications of the single crystal transducers will be discussed. PMID:25386032

  18. Calibration of Field II using a Convex Ultrasound Transducer

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2010-01-01

    BK-Medical (Herlev, Denmark). As input waveform for the Field model we measured the output voltage of the research amplifier, which peak voltage was limited to 31 V to avoid too high non linear effects. We measured the hydrophone output from three transducer front elements by averaging 40 shoot......Field II is an ultrasound simulation program capable of simulating the pressure scattering from inhomogeneous tissue. The simulations are based on a convolution between spatial impulse responses from the field in front of the transducer and the volt-to-surface acceleration impulse response...... of the transducer. For such simulations to reflect actual measured intensities and pressure levels, the transducer impulse response is to be known. This work presents the results of combining a modified form of a 1D linear transducer model originally suggested by Willatzen with the Field II program to calibrate...

  19. Design of matching layers for high-frequency ultrasonic transducers

    Science.gov (United States)

    Fei, Chunlong; Ma, Jianguo; Chiu, Chi Tat; Williams, Jay A.; Fong, Wayne; Chen, Zeyu; Zhu, BenPeng; Xiong, Rui; Shi, Jing; Hsiai, Tzung K.; Shung, K. Kirk; Zhou, Qifa

    2015-09-01

    Matching the acoustic impedance of high-frequency (≥100 MHz) ultrasound transducers to an aqueous loading medium remains a challenge for fabricating high-frequency transducers. The traditional matching layer design has been problematic to establish high matching performance given requirements on both specific acoustic impedance and precise thickness. Based on both mass-spring scheme and microwave matching network analysis, we interfaced metal-polymer layers for the matching effects. Both methods hold promises for guiding the metal-polymer matching layer design. A 100 MHz LiNbO3 transducer was fabricated to validate the performance of the both matching layer designs. In the pulse-echo experiment, the transducer echo amplitude increased by 84.4% and its -6dB bandwidth increased from 30.2% to 58.3% comparing to the non-matched condition, demonstrating that the matching layer design method is effective for developing high-frequency ultrasonic transducers.

  20. A retractable barb needle for drug darts

    Directory of Open Access Journals (Sweden)

    G.L. van Rooyen

    1973-07-01

    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.

  1. Pulmonary actinomycosis in fine needle aspiration cytology

    OpenAIRE

    Patel Keyuri; Gupta Gurudutt; Shah Menka; Patel Purvesh

    2009-01-01

    Pulmonary actinomycosis is a rare bacterial lung disease caused by one of two types of bacteria, Actinomyces or Propioni. Pulmonary actinomycosis in the lung causes lung cavities, lung nodules, and pleural effusion. We report here a case of pulmonary actinomycosis that was diagnosed by fine needle aspiration cytology (FNAC). A 45 year-old male with a history of smoking and alcohol abuse, presented with complaints of cough with hemoptysis, right-sided chest pain, and fever of two months′...

  2. CT Guided Needle Biopsies in Pulmonary Nodules

    Directory of Open Access Journals (Sweden)

    Nargess Afzali

    2011-05-01

    Full Text Available determine the prevalence of pulmonary pathologies"nby CT-guided needle biopsy in pulmonary nodules."nPatients and Methods: We performed CT guided"nneedle biopsy on 78 cases of pulmonary nodules. Lung"nCT scan with a 64-Slice MSCT was done for all patients"nbefore the needle biopsy. All biopsies were performed"nby one experienced interventional radiologist by"nusing a semiautomatic coaxial 18 guage needle. The"nresults were confirmed by two pathologists who were"nunaware of each other's reports. Because of different"npathologic diagnosis two cases were excluded from the"nstudy."nResults: The study population included 43 men and"n33 women with the mean age of 62 years. The mean"nlesion diameter was 22 mm (±7 mm. Thirty-nine"ncases were diagnosed as malignant lesions. Benign"npulmonary conditions were diagnosed in 37 patients."nThe most common malignant lesion was pulmonary"nadenocarcinoma (26%, squamous cell carcinoma"nand bronchoalveolar carcinoma were the next ones."nPulmonary metastasis was seen in three cases and non"nHodgkin lymphoma in three patients. The prevalence"nof adenocarcinoma was not significantly different"nbetween men and women (p value=0.01. The mean age"nof the patients with malignant lesions was 74 years and"n56 years in the others. The difference was significant"n(p=0.05. Tuberculosis was the most common cause of"nbenign lesions (14.4% of all cases, intersitial fibrosis"nand anthracosis were the next most common."nConclusion: Most pulmonary nodules were malignant"nand pulmonary adenocarcinoma was the most"nfrequent. Among benign lesions tuberculosis was the"nmost common."nKeywords: Pulmonary Nodules, Needle Biopsy, CT"nGuide

  3. Exploration of New Electroacupuncture Needle Material

    Directory of Open Access Journals (Sweden)

    Sanghun Lee

    2012-01-01

    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.

  4. Exploration of new electroacupuncture needle material.

    Science.gov (United States)

    Lee, Sanghun; Choi, Gwang-Ho; Lee, Chang Hoon; Kim, Yu Kyoung; Lee, Saebhom; Cho, Sungjin; Yeon, Sunhee; Choi, Sun-Mi; Ryu, Yeon-Hee

    2012-01-01

    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. PMID:22675386

  5. Ultrasound-guided robot for flexible needle steering.

    Science.gov (United States)

    Neubach, Zipi; Shoham, Moshe

    2010-04-01

    The success rate of medical procedures involving needle insertion is often directly related to needle placement accuracy. Due to inherent limitations of commonly used freehand needle placement techniques, there is a need for a system providing for controlled needle steering for procedures that demand high positional accuracy. This paper describes a robotic system developed for flexible needle steering inside soft tissues under real-time ultrasound imaging. An inverse kinematics algorithm based on a virtual spring model is applied to calculate needle base manipulations required for the tip to follow a curved trajectory while avoiding physiological obstacles. The needle tip position is derived from ultrasound images and is used in calculations to minimize the tracking error, enabling a closed-loop needle insertion. In addition, as tissue stiffness is a necessary input to the control algorithm, a novel method to classify tissue stiffness from localized tissue displacements is proposed and shown to successfully distinguish between soft and stiff tissue. The system performance was experimentally verified by robotic manipulation of the needle base inside a phantom with layers of varying stiffnesses. The closed-loop experiment with updated tissue stiffness parameters demonstrated a needle-tip tracking error of approximately 1 mm and proved to be significantly more accurate than the freehand method. PMID:19709957

  6. The effects of needle deformation during lumbar puncture

    Directory of Open Access Journals (Sweden)

    Hasan Hüseyin Özdemir

    2015-01-01

    Full Text Available Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP. Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1% of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3% of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%. Forty-seven (41.5% patients experienced post lumbar puncture headache (PLPH and 13 (11.5% patients experienced intracranial hypotension (IH. No statistically significant correlation between the degree of deflection and headache was found (P > 0.05. Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH.

  7. The effects of needle deformation during lumbar puncture

    Science.gov (United States)

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

    2015-01-01

    Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP). Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1%) of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3%) of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%). Forty-seven (41.5%) patients experienced post lumbar puncture headache (PLPH) and 13 (11.5%) patients experienced intracranial hypotension (IH). No statistically significant correlation between the degree of deflection and headache was found (P > 0.05). Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH. PMID:25883480

  8. Fluoroscopically guided transforaminal epidural dry needling for lumbar spinal stenosis using a specially designed needle

    Directory of Open Access Journals (Sweden)

    Ahn Kang

    2010-08-01

    Full Text Available Abstract Background This report describes the methodological approach and clinical application of a minimally invasive intervention to treat lumbar spinal stenosis (LSS. Methods Thirty-four patients with LSS underwent fluoroscopically guided transforaminal epidural dry needling using a specially designed flexed Round Needle. The needle was inserted 8-12 cm lateral to the midline at the level of the stenosis and advanced to a position between the anterior side of the facet joint and pedicle up to the outer-third of the pedicle. The needle was advanced medially and backed laterally within a few millimetres along the canal side of the inferior articular process between the facet joint and pedicle. The procedure was completed when a marked reduction in resistance was felt at the tip of the needle. The procedure was performed bilaterally at the level of the stenosis. Results The average follow-up period was 12.9 ± 1.1 months. The visual analogue scale (VAS pain score was reduced from 7.3 ± 2.0 to 4.6 ± 2.5 points, the Oswestry Disability Index (ODI score decreased from 41.4 ± 17.2 to 25.5 ± 12.6% and the average self-rated improvement was 52.6 ± 33.1%. The VAS scores indicated that 14 (41.2% patients reported a "good" to "excellent" treatment response, while 11 (32.4% had a "good" to "excellent" treatment response on the ODI and 22 (64.7% had a "good" to "excellent" treatment response on the self-rated improvement scale. Conclusions These results suggest that fluoroscopically guided transforaminal epidural dry needling is effective for managing LSS.

  9. Design of advanced ultrasonic transducers for welding devices.

    Science.gov (United States)

    Parrini, L

    2001-11-01

    A new high frequency ultrasonic transducer has been conceived, designed, prototyped, and tested. In the design phase, an advanced approach was used and established. The method is based on an initial design estimate obtained with finite element method (FEM) simulations. The simulated ultrasonic transducers and resonators are then built and characterized experimentally through laser interferometry and electrical resonance spectra. The comparison of simulation results with experimental data allows the parameters of FEM models to be adjusted and optimized. The achieved FEM simulations exhibit a remarkably high predictive potential and allow full control of the vibration behavior of the transducer. The new transducer is mounted on a wire bonder with a flange whose special geometry was calculated by means of FEM simulations. This flange allows the transducer to be attached on the wire bonder, not only in longitudinal nodes, but also in radial nodes of the ultrasonic field excited in the horn. This leads to a total decoupling of the transducer to the wire bonder, which has not been achieved so far. The new approach to mount ultrasonic transducers on a welding device is of major importance, not only for wire bonding, but also for all high power ultrasound applications and has been patented.

  10. Miniature, high efficiency transducers for use in ultrasonic flow meters

    Science.gov (United States)

    Saikia, Meghna

    This thesis is concerned with the development of a new type of miniature, high efficiency transducer for use in ultrasonic flow meters. The proposed transducer consists of a thin plate of a suitable piezoelectric material on which an inter-digital transducer is fabricated for the generation and detection of plate acoustic waves. When immersed in a fluid medium, this device can convert energy from plate acoustic waves (PAWs) into bulk acoustic waves (BAWs) and vice versa. It is shown that this mode coupling principle can be used to realize efficient transducers for use in ultrasonic flow meters. This transducer can be mounted flush with the walls of the pipe through which fluid is flowing, resulting in minimal disturbance of fluid flow. A prototype flow cell using these transducers has been designed and fabricated. The characteristics of this device have been measured over water flow rates varying from 0 to 7.5 liters per minute and found to be in good agreement with theory. Another attractive property of the new transducers is that they can be used to realize remotely read, passive, wireless flow meters. Details of methods that can be used to develop this wireless capability are described. The research carried out in this thesis has applications in several other areas such as ultrasonic nondestructive evaluation (NDE), noncontact or air coupled ultrasonics, and for developing wireless capability in a variety of other acoustic wave sensors.

  11. Flexible ultrasonic transducers for structural health monitoring

    International Nuclear Information System (INIS)

    Flexible ultrasonic transducers (FUTs) which have on-site installation capability are presented for non-destructive evaluation (NDE) and structural health monitoring (SHM) purposes. These FUTs typically consist of a 70 μm thick piezoelectric lead-zirconate-titanate (PZT) composite (PZT-c) coated by a sol-gel spray technique on a 75 μm thick titanium (Ti) membrane. Such an FUT was glued onto a steel pipe of 101 mm in diameter and 4.5 mm in wall thickness and heated at up to 200oC with the glue serving as a high temperature ultrasonic couplant. The pipe thickness measurement accuracy at 200oC is estimated to be 13 μm. FUTs were also glued onto the end edge of a 2 mm thick aluminum (Al) plate to generate and receive predominantly shear-horizontal (SH) plate acoustic waves (PAWs) to detect simulated line defects at temperatures of up to 100oC. FUTs, glued onto a graphite/epoxy (Gr/Ep) composite plate, were also used for the detection of an artificial disbond. An induction type non-contact method for the evaluation of Al plates and Gr/Ep composites using FUTs is also demonstrated. (author)

  12. Needle Fracture during Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Suspicious Thoracic Lymph Nodes

    Directory of Open Access Journals (Sweden)

    Bartosz Adamowicz

    2016-01-01

    Full Text Available Endoscopic ultrasound fine-needle aspiration (EUS-FNA is used to make a cytopathologic diagnosis of suspicious lesions located around the gastrointestinal tract. It is a safe technique with few complications. The most common complications of EUS-FNA are related to pancreatic lesions (pancreatitis, bleeding, and abdominal pain. Rare complications have been noted such as stent malfunction, air embolism, infection, neural and vascular injuries, and tumor cell seeding. There are very few studies examining equipment malfunctions. We report a case of needle fracture during the EUS-FNA of suspicious thoracic lymph nodes in a 79-year-old man investigated for unexplained weight loss.

  13. ACUPOINT TO ACUPOINT PENETRATIVE NEEDLING AND ITS CLINICAL APPLICATION

    Institute of Scientific and Technical Information of China (English)

    汪洪明

    2001-01-01

    Acupoint to acupoint penetrative needling method has a long history in traditional Chinese medicine. Chinese physicians in various dynasties hold that this type of needling method can strengthen the needling sensations and raise the therapeutic effect in clinical practice. This needling method can be divided into straight penetration, oblique penetration and transverse penetration. In clinical application, it can also be divided into external-medial meridian penetration, a single meridian penetration, neighboring meridians penetration, and neighboring aoupoints penetration, etc. in accordance with the involved acupoints and meridians. Clinical practice demonstrates that penetrative needling possesses advantages of stronger needling sensations, better therapeutic effect and fewer aoupoints selection. For this reason, it is extensively applied in clinic.

  14. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  15. Dynamic mechanism and its modelling of micromachined electrostatic ultrasonic transducers

    Institute of Scientific and Technical Information of China (English)

    葛立峰

    1999-01-01

    A tensile-plate-on-air-spring model (or called TDK model for short) for micromachined electrostatic ultrasonic transducers has been developed based on a thorough investigation of their dynamic mechanism. The mechanical stiffness effects caused by the compressibility of air gaps, bending stiffness of the diaphragm and in-plane tension applied to the diaphragm, together with an electrostatic negative stiffness effect are included completely in the model. Desired particular fundamental frequency and bandwidth can be obtained by only properly tailoring the geometry, dimensions and materials of transducers according to the model, which provides thereby a reliable theoretical basis for the understanding and optimised design of such transducers.

  16. Inter Digital Transducer Modelling through Mason Equivalent Circuit Model

    DEFF Research Database (Denmark)

    Mishra, Dipti; Singh, Abhishek; Hussain, Dil muhammed Akbar;

    2016-01-01

    by Simulation program with Integrated Circuit Emphasis (HSPICE), a well-liked electronic path simulator. The acoustic wave devices are not suitable to simulation through circuit simulator.In this paper, an electrical model of Mason’s Equivalent electricalcircuit for an inter-digital transducer (IDT......The frequency reliance of inter-digital transducer is analyzed with the help of MASON’s Equivalent circuit which is based on Smith’s Equivalent circuit which is further based on Foster’sNetwork. An inter-digital transducer has been demonstratedas a RLC network. The circuit is simulated...

  17. A thermal insulation method for a piezoelectric transducer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study deals with the sources of signal distortion of a piezoelectric transducer heated by measured gas flow. These signal distortions originate from both unloading of preload on a piezocrystal because of expansion of a diaphragm in the test apparatus and the pyroelectric effect of a heated piezoelectric crystal. A plastic film on the diaphragm of the transducer can effectively insulate the diaphragm and the piezocrystal within transducer from heating by gas flow, eliminating the sources of distortion. A method for evaluating the thickness of the film is proposed.

  18. Optimization of ultrasonic transducers for selective guided wave actuation

    Science.gov (United States)

    Miszczynski, Mateusz; Packo, Pawel; Zbyrad, Paulina; Stepinski, Tadeusz; Uhl, Tadeusz; Lis, Jerzy; Wiatr, Kazimierz

    2016-04-01

    The application of guided waves using surface-bonded piezoceramic transducers for nondestructive testing (NDT) and Structural Health Monitoring (SHM) have shown great potential. However, due to difficulty in identification of individual wave modes resulting from their dispersive and multi-modal nature, selective mode excitement methods are highly desired. The presented work focuses on an optimization-based approach to design of a piezoelectric transducer for selective guided waves generation. The concept of the presented framework involves a Finite Element Method (FEM) model in the optimization process. The material of the transducer is optimized in topological sense with the aim of tuning piezoelectric properties for actuation of specific guided wave modes.

  19. USE OF PELTIER COOLERS AS SOIL HEAT FLUX TRANSDUCERS.

    Science.gov (United States)

    Weaver, H.L.; Campbell, G.S.

    1985-01-01

    Peltier coolers were modified and calibrated to serve as soil heat flux transducers. The modification was to fill their interiors with epoxy. The average calibration constant on 21 units was 13. 6 plus or minus 0. 8 kW m** minus **2 V** minus **1 at 20 degree C. This sensitivity is about eight times that of the two thermopile transducers with which comparisons were made. The thermal conductivity of the Peltier cooler transducers was 0. 4 W m** minus **1 degree C** minus **1, which is comparable to that of dry soil.

  20. In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle

    OpenAIRE

    Yu-Tao Li; Li-Na Tang; Yong Ning; Qing Shu; Feng-Xia Liang; Hua Wang; Guo-Jun Zhang

    2016-01-01

    Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip su...

  1. Lab in a needle for epidural space identification

    Science.gov (United States)

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

    2016-05-01

    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. Serrated needle design facilitates precise round window membrane perforation.

    Science.gov (United States)

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

    2016-07-01

    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. PMID:26914984

  3. Electromechanically active polymer transducers: research in Europe

    Science.gov (United States)

    Carpi, Federico; Graz, Ingrid; Jager, Edwin; Ladegaard Skov, Anne; Vidal, Frédéric

    2013-10-01

    Smart materials and structures based on electromechanically active polymers (EAPs) represent a fast growing and stimulating field of research and development. EAPs are materials capable of changing dimensions and/or shape in response to suitable electrical stimuli. They are commonly classified in two major families: ionic EAPs (activated by an electrically induced transport of ions and/or solvent) and electronic EAPs (activated by electrostatic forces). These polymers show interesting properties, such as sizable active strains and/or stresses in response to electrical driving, high mechanical flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise and, in most cases, low costs. Since many of these characteristics can also describe natural muscle tissues from an engineering standpoint, it is not surprising that EAP transducers are sometimes also referred to as 'muscle-like smart materials' or 'artificial muscles'. They are used not only to generate motion, but also to sense or harvest energy from it. In particular, EAP electromechanical transducers are studied for applications that can benefit from their 'biomimetic' characteristics, with possible usages from the micro- to the macro-scale, spanning several disciplines, such as mechatronics, robotics, automation, biotechnology and biomedical engineering, haptics, fluidics, optics and acoustics. Currently, the EAP field is just undergoing its initial transition from academic research into commercialization, with companies starting to invest in this technology and the first products appearing on the market. This focus issue is intentionally aimed at gathering contributions from the most influential European groups working in the EAP field. In fact, today Europe hosts the broadest EAP community worldwide. The rapid expansion of the EAP field in Europe, where it historically has strong roots, has stimulated the creation of the 'European Scientific Network for Artificial

  4. Risk of Needle-track Seeding After Diagnostic Image-guided Core Needle Biopsy in Breast Cancer

    OpenAIRE

    Knight, Rebecca; Horiuchi, Kent; Parker, Steve H.; Ratzer, Erick R.; Fenoglio, Michael E.

    2002-01-01

    Objective: Image-guided core needle biopsy (IGCNB) is an accepted technique for sampling nonpalpable mammographically detected suspicious breast lesions. However, the concern for needle-track seeding in malignant lesions remains. An alternative to IGCNB is needle-localization breast biopsy (NLBB). No study has been done to compare the local recurrence rate of breast cancer after IGCNB versus NLBB. Methods: We have retrospectively reviewed the local recurrence of breast cancer in patients diag...

  5. Polychlorinated naphthalenes in pine needles from Poland

    Energy Technology Data Exchange (ETDEWEB)

    Orlikowska, A.; Falandysz, J.; Bochentin, I. [Dept. of Environmental Chemistry and Ecotoxicology, Univ. of Gdansk (Poland); Hanari, N.; Wyrzykowska, B.; Yamashita, N. [National Inst. of Advanced Industrial Science and Technology (AIST), EMTECH, Tsukuba (Japan)

    2004-09-15

    Polychlorinated naphthalenes (PCNs) are a group of 75 compounds, which have been commercially produced and used in a wide range of industrial applications for the sake of their specific chemical properties. They are recognized as good electrical insulators and also as water and flame resistant materials. Technical PCNs formulations were mainly used as capacitor dielectrics, engine oil additives, electroplating stop-off compounds, in wire insulations and as paper, wood and fabric preservatives. Moreover, they have been formed during production of PCBs formulations. Although recently most countries have stopped synthesis of PCNs, they still are widely distributed in the environment. Nowadays the principal sources of these compounds are municipal solid wastes incineration, metallurgical and chloro-alkali processes. In last years PCNs concentrations in the environment have posed the cynosure of big group of scientists in the whole world. The relatively high concentrations are regarded as an environmental problem. Because they are persistent, toxic and lipophilic they might be bioaccumulated in living organisms and generate the danger for animals and humans. It is essentially to monitor their levels in air, regional transport, as well as estimate specific sources. It is possible by using as a biomonitors pine tree needles. These trees are considered as the very suitable passive indicators for monitoring of PCNs concentrations in the troposphere. This is because the surface wax layer of the needles poses an ability to absorb these lipophilic compounds from the surrounding air. In the current study pine needles were employed as biomonitors of PCNs concentrations in the ambient air of Poland. This country with its past history of production and use of different applications including these compounds, as well as with its location in the centre of Europe, presents the interesting region to these researches.

  6. Transbronchial needle aspiration "by the books"

    Directory of Open Access Journals (Sweden)

    Kupeli Elif

    2011-01-01

    Full Text Available Background : Training for advanced bronchoscopic procedures is acquired during the interventional pulmonology (IP Fellowship. Unfortunately a number of such programs are small, limiting dissemination of formal training. Objective : We studied success of conventional transbronchial needle aspiration (C-TBNA in the hands of physicians without formal IP training. Methods : A technique of C-TBNA was learned solely from the literature, videos and practicing on inanimate models at "Hands-On" courses. Conventional TBNA with 21 and/or 19 gauge Smooth Shot Needles (Olympus® , Japan was performed on consecutive patients with undiagnosed mediastinal lymphadenopathy. Results : Thirty-four patients (male 23, mean age 54.9 ± 11.8 years underwent C-TBNA. Twenty-two patients had nodes larger than 20 mms. Suspected diagnoses were malignancy in 20 and nonmalignant conditions in 14. Final diagnoses were malignancy 17, sarcoidosis 4, reactive lymph nodes 12, and tuberculosis 1. Final diagnosis was established by C-TBNA in 14 (11 malignancy, 3 sarcoidosis; yield 41.1%, mediastinoscopy in 14, transthoracic needle aspiration in 3, peripheral lymph node biopsies in 2 and by endobronchial biopsy in 1. Nodal size had an impact on outcome (P = 0.000 while location did not (P = 0.33. C-TBNA was positive in 11/20 when malignancy was suspected (yield 55%, while 3/14 when benign diagnosis was suspected (yield 21.4% (P = 0.05. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy were 66.6%, 100%, 100%, 65%, and 79.4%, respectively. There were no complications or scope damage. Conclusion : Conventional-TBNA can be learned by the books and by practicing on inanimate models without formal training and results similar to those published in the literature could be achieved.

  7. Needle-based confocal laser endomicroscopy

    OpenAIRE

    Giovannini, Marc

    2015-01-01

    New applications of confocal laser endomicroscopy were developed as pCLE in the bile duct and nCLE for pancreatic cystic tumors, pancreatic masses and lymph nodes. The aim of this paper would be to give you an update in this new technology and to try to define its place in the diagnosis of cystic and solid pancreatic masses. The material used was a 19G EUS-needle in which the stylet was replaced by the Confocal mini-probe. The mini-probe (0.632 mm of diameter) is pre-loaded and screwed by a l...

  8. Stress Distribution on the Fe Based Amorphous Toroidal Transducer Core

    Directory of Open Access Journals (Sweden)

    Mustafa Göktepe

    2014-01-01

    Full Text Available The basic principles of sensors are the transmission of energy from one system to another. In general, an electrical signal is produced by the change of a physical property induced by the applied change of a second parameter. In the case of magnetic transducers either the property or the parameter would have a magnetic context. For example, in magnetoelastic toroidal transducers, the induced changes of a physical property, that is, the variation of permeability caused by the applied external force are used to produce a variation in output signal. The linearity, magnitude, sensitivity, and repeatability of the relationship between the output signal of the transducer and the physical property define the quality of the transducer.

  9. Diode-quad bridge for reactive transducers and FM discriminators

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J.

    1972-01-01

    Diode-quad bridge circuit was developed for use with pressure-sensitive capacitive transducers, liquid-level measuring devices, proximity deflection sensors, and inductive displacement sensors. It may also be used as FM discriminator and as universal impedance bridge.

  10. Transducer for Tension Force Measuring of Strip Materials

    Directory of Open Access Journals (Sweden)

    Emad S. Addasi

    2005-01-01

    Full Text Available In winding-up motor drive systems, such as that used in textile industry, it is very important to get a constant tension force for the winding strip material (thread and to reduce its oscillations. This study recommends a transducer with a special design to be used in the mentioned motor drive systems. By using a piston damper, spring, levers, slider and other simple components the suggested sensor (transducer can be used to control the motor speed for getting the required thread tension force. Also the suggested transducer avoids the disadvantage of other used conventional transducer: the parasitic (detrimental oscillations of the thread tension force, which affect the quality of the produced strip material.

  11. Analytical model of a giant magnetostrictive resonance transducer

    Science.gov (United States)

    Sheykholeslami, M.; Hojjat, Y.; Ansari, S.; Cinquemani, S.; Ghodsi, M.

    2016-04-01

    Resonance transducers have been widely developed and studied, as they can be profitably used in many application such as liquid atomizing and sonar technology. The active element of these devices can be a giant magnetostrictive material (GMM) that is known to have significant energy density and good performance at high frequencies. The paper introduces an analytical model of GMM transducers to describe their dynamics in different working conditions and to predict any change in their performance. The knowledge of the transducer behavior, especially in operating conditions different from the ideal ones, is helpful in the design and fabrication of highly efficient devices. This transducer is design to properly work in its second mode of vibration and its working frequency is around 8000 Hz. Most interesting parameters of the device, such as quality factor, bandwidth and output strain are obtained from theoretical analysis.

  12. High-temperature acoustic transducers for use in LMFBR

    International Nuclear Information System (INIS)

    Progress made in the development of piezo-electric and capacitance transducers for acoustic measurements in fast reactors is described. Lithium niobate, because of its high Curie temperature, was the piezo-electric material selected for a study of response to exposure of reactor conditions of temperature, chemistry and irradiation. Potential applications include microphones and pulse-echo ultrasonic transducers. 7Li NbO3 showed greater irradiation tolerance than LiNbO3. Design considerations, details and manufacturing and calibration techniques are described for a range of piezo-electric devices. Several have been tested in air and sodium and have been used in reactor experiments. Capacitance transducers of a type used in sodium rigs and reactors for years are described. Made from irradiation resistant material, they are unaffected by temperature up to 6000C. Smaller transducers are being developed for work in confined spaces. (U.K.)

  13. Piezoelectric and electrostrictive effects in ferroelectret ultrasonic transducers

    Science.gov (United States)

    Döring, Joachim; Bovtun, Viktor; Gaal, Mate; Bartusch, Jürgen; Erhard, Anton; Kreutzbruck, Marc; Yakymenko, Yuriy

    2012-10-01

    Electromechanical response of polypropylene ferroelectret transducers under application of high-voltage pulses was measured by laser Doppler vibrometry and compared with results of ultrasonic through-air transmission between two ferroelectret transducers. The electromechanical response was completely explained by piezoelectric and electrostrictive effects. The electrostrictive effect dominates at high voltages and provides significant enlargement of the transducer constant, up to factor of 2.5. The induced strain of 1.7% was achieved at -2000 V. The nonlinear ultrasonic transmission was shown to be well described by the piezoelectric and electrostrictive response of transmitter, except in the range of high negative exciting voltages where some limitation of the transmitted signal was observed. This limitation seems not to be a fundamental one and does not abolish the advantages of high-voltage excitation of polypropylene ferroelectret transducers.

  14. Intravitreal Injection of AAV2 Transduces Macaque Inner Retina

    OpenAIRE

    Yin, Lu; Greenberg, Kenneth; Hunter, Jennifer J.; Dalkara, Deniz; Kolstad, Kathleen D; Masella, Benjamin D.; Wolfe, Robert; Visel, Meike; Stone, Daniel; Libby, Richard T.; DiLoreto, David; Schaffer, David; Flannery, John; Williams, David R.; Merigan, William H.

    2011-01-01

    Intravitreally injected AAV2 transduced inner retinal cells in a restricted region at the macaque fovea. Because macaque and human eyes are similar, the results suggest a need to improve transduction methods in gene therapy for the human inner retina.

  15. Wideband Single Crystal Transducer for Bone Characterization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS proposes to develop a simple-to-use, launch capable, ultrasound transducer that is capable of producing the necessary bandwidth to accurately determine in vivo...

  16. Performance Evaluation of Pressure Transducers for Water Impacts

    Science.gov (United States)

    Vassilakos, Gregory J.; Stegall, David E.; Treadway, Sean

    2012-01-01

    The Orion Multi-Purpose Crew Vehicle is being designed for water landings. In order to benchmark the ability of engineering tools to predict water landing loads, test programs are underway for scale model and full-scale water impacts. These test programs are predicated on the reliable measurement of impact pressure histories. Tests have been performed with a variety of pressure transducers from various manufacturers. Both piezoelectric and piezoresistive devices have been tested. Effects such as thermal shock, pinching of the transducer head, and flushness of the transducer mounting have been studied. Data acquisition issues such as sampling rate and anti-aliasing filtering also have been studied. The response of pressure transducers have been compared side-by-side on an impulse test rig and on a 20-inch diameter hemisphere dropped into a pool of water. The results have identified a range of viable configurations for pressure measurement dependent on the objectives of the test program.

  17. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  18. Thermal properties photonic crystal fiber transducers with ferromagnetic nanoparticles

    Science.gov (United States)

    Przybysz, N.; Marć, P.; Kisielewska, A.; Jaroszewicz, L. R.

    2015-12-01

    The main aim of the research is to design new types of fiber optic transducers based on filled photonic crystal fibers for sensor applications. In our research we propose to use as a filling material nanoparticles' ferrofluids (Fe3O4 NPs). Optical properties of such transducers are studied by measurements of spectral characteristics' changes when transducers are exposed to temperature and magnetic field changes. From synthesized ferrofluid several mixtures with different NPs' concentrations were prepared. Partially filled commercially available photonic crystal fiber LMA 10 (NKT Photonics) was used to design PCF transducers. Their thermo-optic properties were tested in a temperature chamber. Taking into account magnetic properties of synthetized NPs the patch cords based on a partially filled PM 1550 PCF were measured.

  19. Traceable dynamic calibration of force transducers by primary means

    Science.gov (United States)

    Vlajic, Nicholas; Chijioke, Ako

    2016-08-01

    We describe an apparatus for traceable, dynamic calibration of force transducers using harmonic excitation, and report calibration measurements of force transducers using this apparatus. In this system, the force applied to the transducer is produced by the acceleration of an attached mass, and is determined according to Newton’s second law, F  =  ma. The acceleration is measured by primary means, using laser interferometry. The capabilities of this system are demonstrated by performing dynamic calibrations of two shear-web-type force transducers up to a frequency of 2 kHz, with an expanded uncertainty below 1.2%. We give an account of all significant sources of uncertainty, including a detailed consideration of the effects of dynamic tilting (rocking), which is a leading source of uncertainty in such harmonic force calibration systems.

  20. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator.

    Science.gov (United States)

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

    2016-01-01

    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

  1. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator

    Science.gov (United States)

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

    2016-01-01

    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

  2. Capacitive Ultrasonic Transducer Development for Acoustic Anemometry on Mars

    Science.gov (United States)

    Leonard-Pugh, Eurion; Wilson, C.; Calcutt, S.; Davis, L.

    2012-10-01

    Previous Mars missions have used either mechanical or thermal anemometry techniques. The moving parts of mechanical anemometers are prone to damage during launch and landing and their inertia makes them unsuited for turbulence studies. Thermal anemometers have been used successfully on Mars but are difficult to calibrate and susceptible to varying ambient temperatures. In ultrasonic anemometry, wind speed and sound speed are calculated from two-way time-of-flight measurements between pairs of transducers; three pairs of transducers are used to return a 3-D wind vector. These high-frequency measurements are highly reliable and immune from drift. Piezo-electric ultrasonic anemometers are widely used on Earth due to their full-range accuracy and high measurement frequency. However these transducers have high acoustic impedances and would not work on Mars. We are developing low-mass capacitive ultrasonic transducers for Mars missions which have significantly lower acoustic impedances and would therefore have a much stronger coupling to the Martian atmosphere. These transducers consist of a metallised polymer film pulled taught against a machined metal backplane. The film is drawn towards the backplane by a DC bias voltage. A varying signal is used on top of the DC bias to oscillate the film; generating acoustic waves. This poster will look at the operation of such sensors and the developments necessary to operate the devices under Martian conditions. Transducer performance is determined primarily by two elements; the front film and the backplane. The sensitivity of the transducer is affected by the thickness of the front film; as well as the diameter, curvature and roughness of the metal backplane. We present data on the performance of the sensors and instrument design considerations including signal shapes and transducer arrangements.

  3. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer

    OpenAIRE

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H.; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-01-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as poly...

  4. Finite-State Complexity and the Size of Transducers

    Directory of Open Access Journals (Sweden)

    Cristian Calude

    2010-08-01

    Full Text Available Finite-state complexity is a variant of algorithmic information theory obtained by replacing Turing machines with finite transducers. We consider the state-size of transducers needed for minimal descriptions of arbitrary strings and, as our main result, we show that the state-size hierarchy with respect to a standard encoding is infinite. We consider also hierarchies yielded by more general computable encodings.

  5. Manipulation of acoustic focusing with an active and configurable planar metasurface transducer.

    Science.gov (United States)

    Zhao, Jiajun; Ye, Huapeng; Huang, Kun; Chen, Zhi Ning; Li, Baowen; Qiu, Cheng-Wei

    2014-01-01

    It has a pivotal role in medical science and in industry to concentrate the acoustic energy created with piezoelectric transducers (PTs) into a specific area. However, previous researches seldom consider the focal resolution, whose focal size is much larger than one wavelength. Furthermore, there is to date no such design method of PTs that allows a large degree of freedom to achieve designed focal patterns. Here, an active and configurable planar metasurface PT prototype is proposed to manipulate the acoustic focal pattern and the focal resolution freely. By suitably optimized ring configurations of the active metasurface PT, we demonstrate the manipulation of focal patterns in acoustic far fields, such as the designed focal needle and multi foci. Our method is also able to manipulate and improve the cross-sectional focal resolution from subwavelength to the extreme case: the deep sub-diffraction-limit resolution. Via the acoustic Rayleigh-Sommerfeld diffraction integral (RSI) cum the binary particle swarm optimization (BPSO), the free manipulation of focusing properties is achieved in acoustics for the first time. Our approach may offer more initiatives where the strict control of acoustic high-energy areas is demanding. PMID:25174409

  6. Home Automation System Based on Intelligent Transducer Enablers

    Directory of Open Access Journals (Sweden)

    Manuel Suárez-Albela

    2016-09-01

    Full Text Available This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers, which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet.

  7. Design of a Smart Ultrasonic Transducer for Interconnecting Machine Applications

    Directory of Open Access Journals (Sweden)

    Chang Xu

    2009-06-01

    Full Text Available A high-frequency ultrasonic transducer for copper or gold wire bonding has been designed, analyzed, prototyped and tested. Modeling techniques were used in the design phase and a practical design procedure was established and used. The transducer was decomposed into its elementary components. For each component, an initial design was obtained with simulations using a finite elements model (FEM. Simulated ultrasonic modules were built and characterized experimentally through the Laser Doppler Vibrometer (LDV and electrical resonance spectra. Compared with experimental data, the FEM could be iteratively adjusted and updated. Having achieved a remarkably highly-predictive FEM of the whole transducer, the design parameters could be tuned for the desired applications, then the transducer is fixed on the wire bonder with a complete holder clamping was calculated by the FEM. The approach to mount ultrasonic transducers on wire bonding machines also is of major importance for wire bonding in modern electronic packaging. The presented method can lead to obtaining a nearly complete decoupling clamper design of the transducer to the wire bonder.

  8. Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

    Science.gov (United States)

    Li, H.; Jung, K. W.; Deng, Z. D.

    2015-11-01

    Implantable acoustic transmitters have been used in the last 20 years to track fish movement for fish survival and migration behavior studies. However, the relatively large weights and sizes of commercial transmitters limit the populations of studied fish. The surgical implantation procedures may also affect fish adversely and incur a significant amount of labor. Therefore, a smaller, lighter, and injectable transmitter was needed, and similar or better acoustic performance and service life over those provided by existing commercial transmitters was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. Our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the signal was not blocked by the transmitter body. We found that a novel off-center tube transducer improved the average source level by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 1.3 dB. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. Lastly, a tuning inductor in series with the transducer was used to help optimize the source level. The findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.

  9. Volumetric loss quantification using ultrasonic inductively coupled transducers

    Science.gov (United States)

    Gong, Peng; Hay, Thomas R.; Greve, David W.; Oppenheim, Irving J.

    2015-03-01

    The pulse-echo method is widely used for plate and pipe thickness measurement. However, the pulse echo method does not work well for detecting localized volumetric loss in thick-wall tubes, as created by erosion damage, when the morphology of volumetric loss is irregular and can reflect ultrasonic pulses away from the transducer, making it difficult to detect an echo. In this paper, we propose a novel method using an inductively coupled transducer to generate longitudinal waves propagating in a thick-wall aluminum tube for the volumetric loss quantification. In the experiment, longitudinal waves exhibit diffraction effects during the propagation which can be explained by the Huygens-Fresnel principle. The diffractive waves are also shown to be significantly delayed by the machined volumetric loss on the inside surface of the thick-wall aluminum tube. It is also shown that the inductively coupled transducers can generate and receive similar ultrasonic waves to those from wired transducers, and the inductively coupled transducers perform as well as the wired transducers in the volumetric loss quantification when other conditions are the same.

  10. Characterization of noncontact piezoelectric transducer with conically shaped piezoelement

    Science.gov (United States)

    Williams, James H., Jr.; Ochi, Simeon C. U.

    1988-01-01

    The characterization of a dynamic surface displacement transducer (IQI Model 501) by a noncontact method is presented. The transducer is designed for ultrasonic as well as acoustic emission measurements and, according to the manufacturer, its characteristic features include a flat frequency response range which is from 50 to 1000 kHz and a quality factor Q of less than unity. The characterization is based on the behavior of the transducer as a receiver and involves exciting the transducer directly by transient pulse input stress signals of quasi-electrostatic origin and observing its response in a digital storage oscilloscope. Theoretical models for studying the response of the transducer to pulse input stress signals and for generating pulse stress signals are presented. The characteristic features of the transducer which include the central frequency f sub o, quality factor Q, and flat frequency response range are obtained by this noncontact characterization technique and they compare favorably with those obtained by a tone burst method which are also presented.

  11. Experimental Evaluation of Three Designs of Electrodynamic Flexural Transducers

    Science.gov (United States)

    Eriksson, Tobias J. R.; Laws, Michael; Kang, Lei; Fan, Yichao; Ramadas, Sivaram N.; Dixon, Steve

    2016-01-01

    Three designs for electrodynamic flexural transducers (EDFT) for air-coupled ultrasonics are presented and compared. An all-metal housing was used for robustness, which makes the designs more suitable for industrial applications. The housing is designed such that there is a thin metal plate at the front, with a fundamental flexural vibration mode at ∼50 kHz. By using a flexural resonance mode, good coupling to the load medium was achieved without the use of matching layers. The front radiating plate is actuated electrodynamically by a spiral coil inside the transducer, which produces an induced magnetic field when an AC current is applied to it. The transducers operate without the use of piezoelectric materials, which can simplify manufacturing and prolong the lifetime of the transducers, as well as open up possibilities for high-temperature applications. The results show that different designs perform best for the generation and reception of ultrasound. All three designs produced large acoustic pressure outputs, with a recorded sound pressure level (SPL) above 120 dB at a 40 cm distance from the highest output transducer. The sensitivity of the transducers was low, however, with single shot signal-to-noise ratio (SNR)≃15 dB in transmit–receive mode, with transmitter and receiver 40 cm apart. PMID:27571075

  12. Piezoelectric films for high frequency ultrasonic transducers in biomedical applications.

    Science.gov (United States)

    Zhou, Qifa; Lau, Sienting; Wu, Dawei; Shung, K Kirk

    2011-02-01

    Piezoelectric films have recently attracted considerable attention in the development of various sensor and actuator devices such as nonvolatile memories, tunable microwave circuits and ultrasound transducers. In this paper, an overview of the state of art in piezoelectric films for high frequency transducer applications is presented. Firstly, the basic principles of piezoelectric materials and design considerations for ultrasound transducers will be introduced. Following the review, the current status of the piezoelectric films and recent progress in the development of high frequency ultrasonic transducers will be discussed. Then details for preparation and structure of the materials derived from piezoelectric thick film technologies will be described. Both chemical and physical methods are included in the discussion, namely, the sol-gel approach, aerosol technology and hydrothermal method. The electric and piezoelectric properties of the piezoelectric films, which are very important for transducer applications, such as permittivity and electromechanical coupling factor, are also addressed. Finally, the recent developments in the high frequency transducers and arrays with piezoelectric ZnO and PZT thick film using MEMS technology are presented. In addition, current problems and further direction of the piezoelectric films for very high frequency ultrasound application (up to GHz) are also discussed.

  13. Software for Correcting the Dynamic Error of Force Transducers

    Directory of Open Access Journals (Sweden)

    Naoki Miyashita

    2014-07-01

    Full Text Available Software which corrects the dynamic error of force transducers in impact force measurements using their own output signal has been developed. The software corrects the output waveform of the transducers using the output waveform itself, estimates its uncertainty and displays the results. In the experiment, the dynamic error of three transducers of the same model are evaluated using the Levitation Mass Method (LMM, in which the impact forces applied to the transducers are accurately determined as the inertial force of the moving part of the aerostatic linear bearing. The parameters for correcting the dynamic error are determined from the results of one set of impact measurements of one transducer. Then, the validity of the obtained parameters is evaluated using the results of the other sets of measurements of all the three transducers. The uncertainties in the uncorrected force and those in the corrected force are also estimated. If manufacturers determine the correction parameters for each model using the proposed method, and provide the software with the parameters corresponding to each model, then users can obtain the waveform corrected against dynamic error and its uncertainty. The present status and the future prospects of the developed software are discussed in this paper.

  14. Experimental Evaluation of Three Designs of Electrodynamic Flexural Transducers.

    Science.gov (United States)

    Eriksson, Tobias J R; Laws, Michael; Kang, Lei; Fan, Yichao; Ramadas, Sivaram N; Dixon, Steve

    2016-01-01

    Three designs for electrodynamic flexural transducers (EDFT) for air-coupled ultrasonics are presented and compared. An all-metal housing was used for robustness, which makes the designs more suitable for industrial applications. The housing is designed such that there is a thin metal plate at the front, with a fundamental flexural vibration mode at ∼50 kHz. By using a flexural resonance mode, good coupling to the load medium was achieved without the use of matching layers. The front radiating plate is actuated electrodynamically by a spiral coil inside the transducer, which produces an induced magnetic field when an AC current is applied to it. The transducers operate without the use of piezoelectric materials, which can simplify manufacturing and prolong the lifetime of the transducers, as well as open up possibilities for high-temperature applications. The results show that different designs perform best for the generation and reception of ultrasound. All three designs produced large acoustic pressure outputs, with a recorded sound pressure level (SPL) above 120 dB at a 40 cm distance from the highest output transducer. The sensitivity of the transducers was low, however, with single shot signal-to-noise ratio ( SNR ) ≃ 15 dB in transmit-receive mode, with transmitter and receiver 40 cm apart. PMID:27571075

  15. Focusing of ferroelectret air-coupled ultrasound transducers

    Science.gov (United States)

    Gaal, Mate; Bartusch, Jürgen; Dohse, Elmar; Schadow, Florian; Köppe, Enrico

    2016-02-01

    Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers.

  16. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator

    Directory of Open Access Journals (Sweden)

    He SY

    2016-06-01

    Full Text Available Siyu He,1 Jose Gomez-Tames,1 Wenwei Yu1,2 1Medical System Engineering Department, Graduate School of Engineering, 2Center for Frontier Medical Engineering, Chiba University, Chiba, Japan Abstract: 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. Keywords: needle-tip localization, needle EMG exam, top-hat transform, tissue-like phantom, voltage distribution simulation

  17. Laser-Controlled Growth of Needle-Shaped Organic Nanoaggregates

    DEFF Research Database (Denmark)

    Balzer, Frank; Rubahn, Horst-Günter

    2002-01-01

    Arrays of mutually parallel oriented, single-crystalline, needle-like structures of light-emitting p-hexaphenyl molecules are generated in the focus of an argon ion laser. The cross sectional dimensions of the needles are of the order of 100 to 200 nm with lengths up to several hundred micrometers...

  18. 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)

    2007-09-21

    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.

  19. Observations on rotating needle insertions using a brachytherapy robot

    Science.gov (United States)

    Meltsner, M. A.; Ferrier, N. J.; Thomadsen, B. R.

    2007-09-01

    A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy.

  20. Coaxial needle insertion assistant with enhanced force feedback.

    Science.gov (United States)

    De Lorenzo, Danilo; Koseki, Yoshihiko; De Momi, Elena; Chinzei, Kiyoyuki; Okamura, Allison M

    2013-02-01

    Many medical procedures involving needle insertion into soft tissues, such as anesthesia, biopsy, brachytherapy, and placement of electrodes, are performed without image guidance. In such procedures, haptic detection of changing tissue properties at different depths during needle insertion is important for needle localization and detection of subsurface structures. However, changes in tissue mechanical properties deep inside the tissue are difficult for human operators to sense, because the relatively large friction force between the needle shaft and the surrounding tissue masks the smaller tip forces. A novel robotic coaxial needle insertion assistant, which enhances operator force perception, is presented. This one-degree-of-freedom cable-driven robot provides to the operator a scaled version of the force applied by the needle tip to the tissue, using a novel design and sensors that separate the needle tip force from the shaft friction force. The ability of human operators to use the robot to detect membranes embedded in artificial soft tissue was tested under the conditions of 1) tip force and shaft force feedback, and 2) tip force only feedback. The ratio of successful to unsuccessful membrane detections was significantly higher (up to 50%) when only the needle tip force was provided to the user. PMID:23193302

  1. Removal of an embedded crochet needle in the mouth.

    Science.gov (United States)

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

    2016-01-01

    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.

  2. Effect of physical disturbance on the structure of needle coke

    Science.gov (United States)

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

    2010-10-01

    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%.

  3. The New-Generation Technology for Making Petroleum Needle Coke

    Institute of Scientific and Technical Information of China (English)

    Shi Changzhi; Shen Haiping; Long Jun; Xie Changjiang

    2003-01-01

    The current technology for producing the petroleum needle coke is apt to cause overflow of feedstock from the coke drums, instability in operation of coking unit, low mechanical strength of petroleum coke, and high percentage of coke powder, leading to difficulties in improving the overall quality of needle coke. Therefore, we have developed a new technology for producing the needle coke,featuring the manipulation of temperature range in a narrow scale at high pressure coupled with feedstock alternations. This new kind of technology has been successfully applied in a 60kt/a commercial coking unit. Provided that demand for the feedstock quality is satisfied, petroleum needle coke meeting the international quality standard can be manufactured using RIPP's technology for producing petroleum needle coke.

  4. Ultrasonic flowmeters: temperature gradients and transducer geometry effects.

    Science.gov (United States)

    Willatzen, M

    2003-03-01

    Ultrasonic flowmeter performance is addressed for the case of cylindrically shaped flowmeters employing two reciprocal ultrasonic transducers A and B so as to measure time-of-flight differences between signals transmitted from transducer A towards B followed by an equivalent signal transmitted from transducer B towards A. In the case where a liquid flows through the flowmeter's measuring section ("spoolpiece"), the arrival times of the two signals differ by an amount related to the flow passing between the two transducers. Firstly, a detailed study of flow measurement errors with mean flow in the laminar flow regime is carried out as a function of the mode index and the transducer diameter/cylinder diameter ratio in the case where no temperature gradients are present in the flowmeter sensor. It is shown that all modes except the fundamental mode overestimate the mean flow by a factor of 33.33% while excitation of the fundamental mode solely give error-free measurements. The immediate consequences are that the flowmeter error decreases as the transducer diameter/cylinder diameter ratio approaches 1 from 0 reflecting the fact that the excitation level of the fundamental mode increases from almost 0 to 1 as this ratio approaches 1 from 0. Secondly, the effect on flowmeter performance due to flow-induced temperature gradients is examined. It is shown that the presence of temperature gradients leads to flowmeter errors at the higher-flow values even in the case where the fundamental mode is the only mode excited. It is also deduced that flowmeter errors in general depend on the distance between transducers A and B whether temperature gradients exist or not. This conclusion is not reflected in the usual definition of flowmeter errors given by the so-called mode-dependent deviation of measurement introduced in earlier works. PMID:12565074

  5. Ozone production of hollow-needle-to-mesh negative corona discharge enhanced by dielectric tube on the needle electrode

    International Nuclear Information System (INIS)

    For the hollow-needle-to-mesh negative corona discharge in air, we studied the effect of placing the dielectric tube on the needle electrode and the effect of various positions of the end of this tube with respect to the tip of the needle electrode on the concentration of ozone produced by the discharge, the ozone production yield and the discharge V–A characteristics. We found that the placement of the dielectric tube on the needle electrode with a suitable position of this tube end with respect to the tip of the needle electrode for a particular discharge power led to a more than fourfold increase in the concentration of ozone produced by the discharge and also, for a constant airflow, the ozone production yield. (fast track communication)

  6. Design of a saturated analogue and digital current transducer

    International Nuclear Information System (INIS)

    This project describes the development of a new analogue and digital current transducer, providing a range of new theoretical design methods for these novel devices. The main control feature is the limit cycling operation, and the novel use of the embedded sigma-delta modulator sensor structure to derive a low component count digital sensor. The research programme was initiated into the design, development and evaluation of a novel non-Hall sensing analogue and digital current transducer. These transducers are used for measurement of high currents in power systems applications. The investigation is concerned with a new design which uses a magnetic ferrite core without an air gap for current measurement. The motivation for this work was to design a new control circuit which provides a low component count, and utilises the non-linear properties of the magnetic ferrite core to transmit direct current. The use of a limit cycle control circuit was believed to be particularly suitable for the analogue and digital transducers, for two main reasons: the low component count, and the output signal is directly digital. In line with the motivations outlined above, the outcome of the research has witnessed the design, development and evaluation of a practically realisable analogue and digital current transducer. The design procedure, which is documented in this thesis, is considered to be a major contribution to the field of transducers design and development using a control systems approach. Mathematical models for both analogue and digital transducers were developed and the resulting model based predictions were found to be in good agreement with measured results. Simplification of the new model sensing device was achieved by approximating the non-linear ferrite core using FFT analysis. This is also considered to be a significant contribution. The development analogue and digital current censors employed a sampled data control systems design and utilised limit cycling

  7. [Design of acupoint electric characteristic sensing needle].

    Science.gov (United States)

    Liu, Tang-yi; Yang, Hua-yuan; Kuai, Le; Gao, Ming

    2007-09-01

    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.

  8. Pulmonary actinomycosis in fine needle aspiration cytology

    Directory of Open Access Journals (Sweden)

    Patel Keyuri

    2009-01-01

    Full Text Available Pulmonary actinomycosis is a rare bacterial lung disease caused by one of two types of bacteria, Actinomyces or Propioni. Pulmonary actinomycosis in the lung causes lung cavities, lung nodules, and pleural effusion. We report here a case of pulmonary actinomycosis that was diagnosed by fine needle aspiration cytology (FNAC. A 45 year-old male with a history of smoking and alcohol abuse, presented with complaints of cough with hemoptysis, right-sided chest pain, and fever of two months′ duration. A chest radiograph and computed tomography (CT of the thorax showed a right upper lobe mass lesion with hilar lymphadenopathy. CT-guided FNAC revealed colonies of Actinomyces surrounded by polymorphs. The disease is commonly confused with other chronic suppurative lung diseases and malignancy. An early diagnosis by FNAC prevents difficulties in the management of the disease, as well as considerable physiological and physical morbidity, including unwarranted surgery.

  9. Transurethral microwave needle ablation for bladder cancer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@To investigate the role of transurethral microwave needle ablation (TUMWNA) in the management of bladder cancer,TUMWNA was carried out in 24 patients with bladder cancer since 1989. From January 1989 to December 1997, 24 patients with bladder cancer were treated with TUMWNA. The 15 men and 9 women were 42 to 67 years old (mean, 58). There were 18 cases with a single tumor and 6 with multiple tumors (4 with 2 tumors, 1 with 3 and 1 with 4). Tumor diameter ranged from 0.3 to 2.5 cm. The lesions grew in different bladder regions: 13 tumors arose from the fundus, 3 tumors from the dome, 9 from the lateral wall, 5 from the anterior wall, 1 from the triangle region and 2 tumors were situated in the obturator nerve reflex sensitive region.

  10. Fine-needle aspiration cytology in fibromatoses.

    Science.gov (United States)

    Zaharopoulos, P; Wong, J Y

    1992-01-01

    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.

  11. 1-3 Piezocomposite transducers for AUV applications

    Science.gov (United States)

    Pazol, Brian; Lannaman, Ken; Doust, Barry

    2001-05-01

    Sonar systems on board AUVs present interesting challenges to the transducer designer because of their small size, low weight requirements, and limited available power. 1-3 piezocomposite transducers offer many performance characteristics which make them ideal for deployment in AUVs. Piezocomposite transducers are light weight, have broad bandwidth, have high efficiency, and can be conformed to fit the curvature of the vehicle. The broad bandwidths and low sidelobes made possible by piezocomposites result in sharper images with less distortion. The piezocomposite material is mechanically robust and can survive the rigors of normal operations as well as AUV deployment and retrieval. In addition, the conformal configuration substantially reduces hydrodynamic drag. As a conformal array, there is nothing to get knocked off during deployment and retrieval operations, or entangled with natural or man-made objects suspended in the water column. This contributes directly to improving the operational endurance of the AUV system, thereby enhancing overall system utility. MSI has produced and tested a variety of piezocomposite transducers for use in obstacle avoidance, mine hunting, and acoustic communications. An overview of piezocomposites and recent results of piezocomposite transducers will be presented.

  12. Design of Capacitance to Voltage Converter for Capacitive Sensor Transducer

    Directory of Open Access Journals (Sweden)

    A. H.M.Z. Alam

    2010-01-01

    Full Text Available Problem statement: The design of Capacitance to Voltage Converter (CVC for capacitive sensor transducer was presented. The proposed design will reduce the size, power consumption and supply voltage of the circuit and can be used in high frequency band transducer. Approach: The design was implemented using the Operational amplifier (Op amp and capacitive network. The circuit was simulated using the PSPICE model parameters based on standard 0.13 μm CMOS process. Results: The design was able to measure a wide range of capacitance variations for the capacitive transducer. The performance analysis of the design showed desirable performance parameters in terms of response, low power consumption and a linear output voltage within the wide range of capacitive transducer capacitance variation for the power supply voltage of 1.2 V was achieved. Conclusion/Recommendations: The output voltage of the circuit varied linearly with the variation of capacitive transducer capacitance variation. The improved converter was compact and robust for integration into capacitive measuring systems and suitable for use in environment that making use of higher frequency band.

  13. Piezoelectric Polymer Ultrasound Transducers and Its Biomedical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kang Lyeol; Cao, Yanggang [Department of Physics, Pukyong National University, Busan (Korea, Republic of)

    2012-10-15

    PVDF(poly vinylidene fluoride) and P(VDF-TrFE)(poly vinylidene fluoride-tetrafluoroethylene) are the typical piezoelectric polymers with unique properties. Even they are inferior to conventional piezoelectric ceramics PZT in electromechanical conversion efficiency and interior loss, though they are superior in receiving sensitivity and frequency bandwidth. Their acoustic impedances are relatively close to water or biological tissue and it is easier to make thin film than other piezoelectric materials. Furthermore, the film is so flexible that it is easy to attach on a complex surface. Those properties are suitable for the ultrasound transducers which are useful for medical and biological application, so that various types of polymer transducers have been developed. In this paper, several important considerations for design and fabrication of piezoelectric polymer transducers were described and their effect on the transducer performance were demonstrated through the KLM model analysis. Then, it was briefly reviewed about the structures of the polymer transducers developed for obtaining images as well as the characteristics of the images in several important medical and biological application fields.

  14. Long-Term Stability of the NIST Conical Reference Transducer.

    Science.gov (United States)

    Fick, Steven E; Proctor, Thomas M

    2011-01-01

    The National Institute of Standards and Technology (NIST) Conical Reference Transducer (CRT) is designed for purposes requiring frequency response characteristics much more uniform than those attainable with ultrasonic transducers conventionally used for acoustic emission (AE) nondestructive testing. The high performance of the CRT results from the use of design elements radically different from those of conventional transducers. The CRT was offered for sale for 15 years (1985 to 2000). Each CRT was furnished with data which expressed, as a function of frequency, the transducer sensitivity in volts per micrometer of normal displacement on the test block. Of the 22 transducers constructed, eight were reserved for long term research and were stored undisturbed in a laboratory with well controlled temperature and humidity. In 2009, the sensitivities of these eight units were redetermined. The 2009 data have been compared with data from similar tests conducted in 1985. The results of this comparison verify the claim "Results of tests of the long term stability of CRT characteristics indicate that, if proper care is taken, tens of years of service can reasonably be expected." made in the CRT specifications document furnished to prospective customers. PMID:26989602

  15. Characterization of Transducers and Resonators under High Drive Levels

    Science.gov (United States)

    Sherrit, Stewart; Bao, X.; Sigel, D. A.; Gradziel, M. J.; Askins, S. A.; Dolgin, B. P.; Bar-Cohen, Y.

    2001-01-01

    In many applications, piezoelectric transducers are driven at AC voltage levels well beyond the level for which the material was nominally characterized. In this paper we describe an experimental setup that allows for the determination of the main transducer or resonator properties under large AC drive. A sinusoidal voltage from a waveform generator is amplified and applied across the transducer/resonator in series with a known high power resistor. The amplitude of applied voltage and the amplitude and the relative phase of the current through the resistor are monitored on a digital scope. The frequency of the applied signal is swept through resonance and the voltage/current signals are recorded. After corrections for the series resistance and parasitic elements the technique allows for the determination of the complex impedance spectra of the sample as a function of frequency. In addition, access to the current signal allows for the direct investigation of non-linear effects through the application of Fourier transform techniques on the current signal. Our results indicate that care is required when interpreting impedance data at high drive level due to the frequency dependence of the dissipated power. Although the transducer/resonator at a single frequency and after many cycles may reach thermal equilibrium, the spectra as a whole cannot be considered an isothermal measurement due to the temperature change with frequency. Methods to correct for this effect will be discussed. Results determined from resonators of both soft and hard PZT and a ultrasonic horn transducer are presented.

  16. Ultrasonic array of thick film transducers for biological tissue characterization.

    Science.gov (United States)

    Gwirc, Sergio N; Negreira, Carlos A; Marino, Nestor R

    2010-01-01

    The initial motivation for this work was to accomplish an easy way to manufacture different geometries of ultrasonic transducers and arrays using a PZT powder, combined with a standard process to have repetitive series of them. The piezoelectric thick film was obtained using a PZT paste and applying it by screen printing on an alumina substrate. Then, the film was drying and sintered with a temperature-time profile determined by the paste characteristics. Each transducer is composed by three layers, one by PZT and two acting as electrodes. The active element of the paste is a PZT powder which is dispersed in a commercial vehicle to obtain rheological properties suitable for use the screen printing process. The connection between PZT particles is improved by adding a lead borosilicate frit glass that also helps to attach the film to the substrate due to the relatively low temperature of sintered that has been used in this process. The PZT film has low density that is generated by internal porosity, so its acoustic impedance is lower than for a bulk ceramic transducer and so is well adapted to testing human tissues. At the same time the thick film technology is well suited to make medium size transducers and also arrays performed with tiny ultrasonic transducers. PMID:21097177

  17. Delimitation of the lung region with distributed ultrasound transducers

    Science.gov (United States)

    Cardona Cárdenas, Diego Armando; Furuie, Sérgio Shiguemi

    2016-04-01

    One technique used to infer and monitor patient's respiratory conditions is the electrical impedance tomography (EIT). This provides images with information about lung function. The EIT image contrast is dependent on the variation of electrical impedance, therefore, this image does not provide anatomical details in border regions of several organs. To contribute to a clinical solution, we propose a new method to delimit regions of interest such as the pulmonary region and to improve the reconstruction quality of the EIT. Using a Matlab Toolbox k-wave, the ultrasound propagation phenomenon in homogeneous medium without patient (Reference) and with thoracic models were simulated, separately via a set of several ultrasound transducers distributed around the chest. After pulse emission by a transducer (TR), all received signals were compared considering the two sets of signals. If the energy relation between parts of the signals does not exceed an empirical threshold (30% in this study), a partial mask is generated between the transmitter and the receptor. This process was repeated until all 128 transducers are considered as TR-emitters. The 128 transducers (150kHz) are uniformly distributed. The evaluation was made by visually comparing the resulting images with the respective simulated object. A simple approach was presented to delimit high contrast organs with ultrasound transducers distributed around the patient. This approach allows other lower contrast objects to become invisible by varying the threshold limit. The investigation, based on numerical simulations of ultrasonic propagation, has shown promising results in the delimitation of the pulmonary region.

  18. Needle steering for robot-assisted insertion into soft tissue: A survey

    Science.gov (United States)

    Gao, Dedong; Lei, Yong; Zheng, Haojun

    2012-07-01

    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.

  19. Emergency percutaneous needle decompression for tension pneumoperitoneum

    Directory of Open Access Journals (Sweden)

    Körner Markus

    2011-05-01

    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. Adequate histologic sectioning of prostate needle biopsies.

    Science.gov (United States)

    Bostwick, David G; Kahane, Hillel

    2013-08-01

    No standard method exists for sampling prostate needle biopsies, although most reports claim to embed 3 cores per block and obtain 3 slices from each block. This study was undertaken to determine the extent of histologic sectioning necessary for optimal examination of prostate biopsies. We prospectively compared the impact on cancer yield of submitting 1 biopsy core per cassette (biopsies from January 2010) with 3 cores per cassette (biopsies from August 2010) from a large national reference laboratory. Between 6 and 12 slices were obtained with the former 1-core method, resulting in 3 to 6 slices being placed on each of 2 slides; for the latter 3-core method, a limit of 6 slices was obtained, resulting in 3 slices being place on each of 2 slides. A total of 6708 sets of 12 to 18 core biopsies were studied, including 3509 biopsy sets from the 1-biopsy-core-per-cassette group (January 2010) and 3199 biopsy sets from the 3-biopsy-cores-percassette group (August 2010). The yield of diagnoses was classified as benign, atypical small acinar proliferation, high-grade prostatic intraepithelial neoplasia, and cancer and was similar with the 2 methods: 46.2%, 8.2%, 4.5%, and 41.1% and 46.7%, 6.3%, 4.4%, and 42.6%, respectively (P = .02). Submission of 1 core or 3 cores per cassette had no effect on the yield of atypical small acinar proliferation, prostatic intraepithelial neoplasia, or cancer in prostate needle biopsies. Consequently, we recommend submission of 3 cores per cassette to minimize labor and cost of processing. PMID:23764163

  1. In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle

    Science.gov (United States)

    Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun

    2016-06-01

    Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment.

  2. 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

    2006-01-01

    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

  3. Reducing the Effect of Transducer Mount Induced Noise on Aeroacoustic Wind Tunnel Testing Data with a New Transducer Mount Design

    Science.gov (United States)

    Herron, A. J.; Reed, D. K.; Nance, D. K.

    2015-01-01

    Characterization of launch vehicle unsteady aerodynamics is a field best studied through experimentation, which is often carried out in the form of large scale wind tunnel testing. Measurement of the fluctuating pressures induced by the boundary layer noise is customarily made with miniature pressure transducers installed into a model of the vehicle of interest. Literature shows that noise level increases between two to five decibels (dB referenced to 20 micropascal) can be induced when the transducer surface is not mounted perfectly flush with the model outer surface. To reduce this artificially induced noise, special transducer holders have been used for aeroacoustic wind tunnel testing by NASA. This holder is a sleeve into which the transducer fits, with a cap that allows it to be mounted in a recessed hole in the model. A single hole in the holder allows the transport of the tunnel medium so the transducer can discriminate the fluctuating pressure due to the turbulent boundary layer noise. The holder is first dry fitted into the model and any difference in height between the holder and the model surface can be sanded flush. The holder is then removed from the model, the transducer glued inside the holder, and the holder replaced in the model, secured also with glue, thus eliminating the problem of noise level increases due to lack of flushness. In order to work with this holder design, special transducers have been ordered with their standard screen removed and the diaphragm moved as close to the top of the casing as possible to minimize any cavity volume. Although this greatly reduces induced noise due to the transducers being out of flush, the holders can also induce a cavity resonance that is usually at a very high frequency. This noise is termed transducer mount induced noise (XMIN). The peak of the mode can vary with the cavity depth, boundary layer noise that can excite the mode, tunnel flow medium, and the build of the transducers. Because the boundary

  4. INFLUENCE OF PIEZOELECTRIC TRANSDUCER TO GLASS FIBER REINFORCED COMPOSITE STIFFNESS

    Directory of Open Access Journals (Sweden)

    Witold Rządkowski

    2015-08-01

    Full Text Available The main goal was to determine if transducers based on piezoelectric materials are suitable for strain calculations in thin GFRP specimens. Numerous experimental studies, both physical and numerical, performed by the authors, have shown that there is a huge influence of bonded piezoelectric transducer on the overall stiffness of the measured object. The paper presents tensile test performed on strength machine with Digital Image Correlation strain and deflection observations. Test were compared with FEM models for detailed investigation. The main conclusion is piezoelectric transducers has huge influence on local stiffness of measured object. That is critical especially when they are used as strain sensors, when presence of sensor is influencing to measured results.

  5. Energy harvesting with a slotted-cymbal transducer

    Institute of Scientific and Technical Information of China (English)

    Jiang-bo YUAN; Xiao-biao SHAN; Tao XIE; Wei-shan CHEN

    2009-01-01

    A cymbal transducer is made up of a piezoceramic disk sandwiched between two dome-shaped metal endcaps. High circumferential stresses caused by flexural motion of the metal endcaps can induce the loss of mechanical input energy. Finite element analysis shows that the radial slots fabricated in metal endcaps can release the circumferential stresses, and reduce the loss of mechanical input energy that could be converted into electrical energy. In this letter, the performance of a slotted-cymbal transducer in energy harvesting was tested. The results show that the output voltage and power of the cymbal are improved. A maximum output power of around 16 mW could be harvested from a cymbal with 18 cone radial slots across a 500kΩ resistive load, which is approximately 0.6 times more than that of the original cymbal transducer.

  6. Ultrasonic waveguide transducer for high temperature testing of ceramic honeycomb

    Science.gov (United States)

    Wang, N.; An, C. P.; Nickerson, S. T.; Gunasekaran, N.; Shi, Z.

    2013-01-01

    This paper describes the development of a practical ultrasonic waveguide transducer designed for in situ material property characterization of ceramic honeycomb at high temperatures (>1200°C) and under fast thermal cycles (>1000°C/min). The low thermal conductivity MACOR waveguide allows the use of conventional transducer (max temp. 50°C) at one end and guides ultrasonic waves into the high temperature region where the characterization is carried out. The impact of time, temperature, and heating/cooling rates on the material behavior was studied. It was demonstrated that the same transducer could also be used for in-situ crack detection during the thermal shock testing of ceramic honeycomb.

  7. Improved capacitive stress transducers for high-field superconducting magnets

    Science.gov (United States)

    Benson, Christopher Pete; Holik, Eddie Frank, III; Jaisle, Andrew; McInturff, A.; McIntyre, P.

    2012-06-01

    High-field (12-18 Tesla) superconducting magnets are required to enable an increase in the energy of future colliders. Such field strength requires the use of Nb3Sn superconductor, which has limited tolerance for compressive and shear strain. A strategy for stress management has been developed at Texas A&M University and is being implemented in TAMU3, a short-model 14 Tesla stress-managed Nb3Sn block dipole. The strategy includes the use of laminar capacitive stress transducers to monitor the stresses within the coil package. We have developed fabrication techniques and fixtures, which improve the reproducibility of the transducer response both at room temperature and during cryogenic operation. This is a report of the status of transducer development.

  8. Apparent transducer non-reciprocity in an ultrasonic flow meter.

    Science.gov (United States)

    van Deventer, Jan; Delsing, Jerker

    2002-05-01

    This paper investigates the effects of non-identical ultrasonic transducers on reciprocity and zero-flow calibration in transit time flow meters. According to the theorem of reciprocity, there should not be any difference between the up- and downstream acoustic times of flight in a zero-flow situation. This would thus eliminate zero-flow estimation drifts. The flow meter is modeled as a one dimensional system with equivalent electrical circuits and simulated with simulation program with integrated circuits emphasis. The work shows that variations between the two transducers cause false estimates of flow and indicate which parameters have the largest influence. It indicates that reciprocity holds only for identical transducers. PMID:12159974

  9. A Low Frequency Broadband Flextensional Ultrasonic Transducer Array.

    Science.gov (United States)

    Savoia, Alessandro Stuart; Mauti, Barbara; Caliano, Giosuè

    2016-01-01

    In this paper, we propose the design and the fabrication of a multicell, piezoelectrically actuated, flextensional transducer array structure, characterized by a low mechanical impedance, thus allowing wideband and high-sensitivity immersion operation in the low ultrasonic frequency range. The transducer structure, consisting of a plurality of circular elementary cells orderly arranged according to a periodic hexagonal tiling, features a high flexibility in the definition of the active area shape and size. We investigate, by finite element modeling (FEM), the influence of different piezoelectric and elastic materials for the flexural plate, for the plate support and for the backing, on the transducer electroacoustic behavior. We carry out the dimensioning of the transducer components and cell layout, in terms of materials and geometry, respectively, by aiming at a circular active area of 80-mm diameter and broadband operation in the 30-100-kHz frequency range in immersion. PZT-5H ceramic disks and a calibrated thickness stainless steel plate are chosen for the vibrating structure, and FR-4 laminates and a brass plate, respectively, for the plate support and the backing. The diameter of the individual cells is set to 6 mm resulting in 121 cells describing a quasi-circular area, and the total thickness of the transducer is less than 10 mm. We report on the fabrication process flow for the accurate assembly of the transducer, based, respectively, on epoxy resin and wire bonding for the mechanical and electrical interconnection of the individual parts. The results of the electrical impedance and transmit pressure field characterization are finally reported and discussed. PMID:26540680

  10. High intensity ultrasound transducer used in gene transfection

    Science.gov (United States)

    Morrison, Kyle P.; Keilman, George W.; Noble, Misty L.; Brayman, Andrew A.; Miao, Carol H.

    2012-11-01

    This paper describes a novel therapeutic high intensity non-focused ultrasound (HIU) transducer designed with uniform pressure distribution to aid in accelerated gene transfer in large animal liver tissues in vivo. The underlying HIU transducer was used to initiate homogeneous cavitation throughout the tissue while delivering up to 2.7 MPa at 1.1 MHz across its radiating surface. The HIU transducer was built into a 6 cm diameter x 1.3 cm tall housing ergonomically designed to avoid collateral damage to the surrounding anatomy during dynamic motion. The ultrasound (US) radiation was applied in a 'paintbrush-like' manner to the surface of the liver. The layers and geometry of the transducer were carefully selected to maximize the active diameter (5.74 cm), maximize the electrical to acoustic conversion efficiency (85%) to achieve 2.7 MPa of peak negative pressure, maximize the frequency operating band at the fundamental resonance to within a power transfer delta of 1 dB, and reduce the pressure delta to within 2 dB across the radiating surface. For maximum peak voltage into the transducer, a high performance piezoceramic was chosen and a DC bias circuit was built integral to the system. An apodized two element annular pattern was made from a single piezoceramic element, resulting in significant pressure uniformity enhancement. In addition to using apodization for pressure uniformity, a proprietary multi-layered structure was used to improve efficiency while sustaining an operating band from 900 kHz to 1.3 MHz. The resultant operating band allowed for dithering techniques using frequency modulation. The underlying HIU transducer for use in large animals enhances gene expression up to 6300-fold.

  11. 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

    2011-01-01

    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.

  12. Why should we use atraumatic needles in lumbar puncture?

    Directory of Open Access Journals (Sweden)

    Sandro Luiz de Andrade Matas

    2013-09-01

    Full Text Available Diagnostic lumbar puncture is essential to the diagnosis of central nervous system infections, subarachnoid haemorrhage and others neurological diseases. Myeloradicular involvement or life-threatening adverse events due to the procedure are rare, but less severe complications are more frequent. Post-lumbar puncture headache is the most common complication, by spinal fluid leakage due to delayed closure of a dural defect. Therefore, the development of fine needles, with differentiated atraumatic bevel, has contributed to minimize that problem. These generically called atraumatic needles cause less deformation of the dura mater then the Quincke® ones. So, why don't we use these atraumatic needles?

  13. Diagenesis of conifer needles in a coastal marine environment

    Science.gov (United States)

    Hedges, John I.; Weliky, K.

    1989-10-01

    Physically intact fir, hemlock and cedar needles were isolated from different horizons of a sediment core from a coastal marine bay (Dabob Bay, Washington State, U.S.A.) and from nearby trees and forest litter. Green fir, hemlock and cedar needles were all characterized by glucose-rich aldose mixtures (~30% of tissue carbon), the production of vanillyl and cinnamyl CuO-derived phenols (~8% of tissue carbon) and the presence of both pinitol and myo-inositol (1-2% of tissue carbon). Needles from forest litter were enriched in lignin phenols and non-glucose aldoses and depleted in glucose and cyclitols. The sediment core contained an average of 10 mg/1 of physically intact fir, hemlock and cedar needles, which occurred in similar relative abundances and accounted for less than 1% of the total nonwoody gymnosperm tissue. Compared to the green and litter counterparts, all sedimentary needles were greatly depleted in cyclitols, glucose and p-coumaric acid and enriched in vanillyl phenol precursors. The degree of elevation of vanillyl phenol yield from the degraded needles was used to estimate minimal carbon losses from the samples, which ranged from near 40% for needle litter to almost 70% for the deepest (~100 years old) sedimentary fir/hemlock samples. Although downcore increases in carbon loss and refractory organic components indicated in situ diagenesis, the bulk of overall degradation occurred either on land or during the first 10-20 years after deposition. Atomic C/N ratios of degraded needles were lower than for green counterparts, but nitrogen was lost overall. These relative changes indicate the following stability series: vanillyl phenols > N > ferulic acid, p-hydroxy phenols, most aldoses and bulk tissue > glucose and p-coumaric acid > cyclitols (near 100% loss). Vanillic acid to vanillin ratios, (Ad/Al)v, of the green fir and hemlock needles were unusually high (0.36-0.38) and decreased downcore. Diagenesis also decreased the cinnamyl/vanillyl phenol ratio

  14. On the use of hypodermic needles in electrospray

    Directory of Open Access Journals (Sweden)

    Gañán-Calvo A.M.

    2013-04-01

    Full Text Available We present an experimental analysis of electrospray where the standard feeding capillary was re- placed with a hypodermic needle. Both the current intensity and the jet diameter were measured for a variety of leaky-dielectric liquids. The results obtained with a feeding capillary and a hypodermic needle of similar dimen- sions were compared. An increase of the liquid conductivity was measured by assuming that the electric current obeys the same scaling law in both configurations. That increase was likely due to the electrochemical reaction taking place in the needle tip.

  15. Transducers for Sound and Vibration - FEM Based Design

    DEFF Research Database (Denmark)

    Liu, Bin

    2001-01-01

    for methods that can reduce the design time consumption and the number of itterations. The present work proposes to use finite element based programs for simulating the behaviour of a transducer with a given set of specifications. A simulation program for accelerometers was developed and has been tested......Design of transducers for measurement of vibration (piezoelectric accelerometers) and sound (condenser microphones) is a very labour intensive work. The design work is mostly based on experience and on simple analogies to electrical circuit design. Often a time consuming itterative loop is used...

  16. Thermal energy harvesters with piezoelectric or electrostatic transducer

    Science.gov (United States)

    Prokaryn, Piotr; Domański, Krzysztof; Marchewka, Michał; Tomaszewski, Daniel; Grabiec, Piotr; Puscasu, Onoriu; Monfray, Stéphane; Skotnicki, Thomas

    2014-08-01

    This paper describes the idea of the energy harvester which converts thermal gradient present in environment into electricity. Two kinds of such devices are proposed and their prototypes are shown and discussed. The main parts of harvesters are bimetallic spring, piezoelectric transducer or electrostatic transducer with electret. The applied piezomembrane was commercial available product but electrets was made by authors. In the paper a fabrication procedure of electrets formed by the corona discharge process is described. Devices were compared in terms of generated power, charging current, and the voltage across a storage capacitor.

  17. Qualification of indigenously developed sodium compatible ultrasonic transducers for PFBR

    International Nuclear Information System (INIS)

    PFBR core is immersed in a pool of optically opaque liquid sodium at high temperature. Ultrasonic technique is utilized to view the components immersed in sodium. An under sodium ultrasonic scanner (USUSS) with indigenously developed sodium compatible transducers are used to scan the core plenum before every fuel handling operation, when the temperature of sodium is around 180℃. There are two different types of transducers, one for the measurement of bowing and the other is used for the protrusion measurement of any fuel sub assembly (FSA). (author)

  18. Wideband Single-Crystal Transducer for Bone Characterization

    Science.gov (United States)

    Liang, Yu; Snook, Kevin

    2012-01-01

    The microgravity conditions of space travel result in unique physiological demands on the human body. In particular, the absence of the continual mechanical stresses on the skeletal system that are present on Earth cause the bones to decalcify. Trabecular structure decreases in thickness and increases in spacing, resulting in decreased bone strength and increased risk of injury. Thus, monitoring bone health is a high priority for long-term space travel. A single probe covering all frequency bands of interest would be ideal for such measurements, and this would also minimize storage space and eliminate the complexity of integrating multiple probes. This invention is an ultrasound transducer for the structural characterization of bone. Such characterization measures features of reflected and transmitted ultrasound signals, and correlates these signals with bone structure metrics such as bone mineral density, trabecular spacing, and thickness, etc. The techniques used to determine these various metrics require measurements over a broad range of ultrasound frequencies, and therefore, complete characterization requires the use of several narrowband transducers. This is a single transducer capable of making these measurements in all the required frequency bands. The device achieves this capability through a unique combination of a broadband piezoelectric material; a design incorporating multiple resonator sizes with distinct, overlapping frequency spectra; and a micromachining process for producing the multiple-resonator pattern with common electrode surfaces between the resonators. This device consists of a pattern of resonator bars with common electrodes that is wrapped around a central mandrel such that the radiating faces of the resonators are coplanar and can be simultaneously applied to the sample to be measured. The device operates as both a source and receiver of acoustic energy. It is operated by connection to an electronic system capable of both providing an

  19. Simulating Capacitive Micromachined Ultrasonic Transducers (CMUTs) using Field II

    DEFF Research Database (Denmark)

    Bæk, David; Oralkan, Omer; Kupnik, Mario;

    2010-01-01

    Field II has been a recognized simulation tool for piezoceramic medical transducer arrays for more than a decade. The program has its strength in doing fast computations of the spatial impulse response (SIR) from array elements by dividing the elements into smaller mathematical elements (ME)s from...... which it calculates the SIR responses. The program features predefined models for classical transducer geometries, but currently none for the fast advancing CMUTs. This work addresses the assumptions required for modeling CMUTs with Field II. It is shown that rectangular array elements, populated...

  20. Transverse Oscillation Vector Velocity Estimation using a Phased Array Transducer

    DEFF Research Database (Denmark)

    Marcher, Jønne; Pihl, Michael Johannes; Seerup, Gert;

    2012-01-01

    The Transverse Oscillation method has shown its commercial feasibility, providing the user with 2D velocity information. Todays implementation on commercial ultrasound platforms only support linear array transducers and are limited in depth. Extending the implementation to a phased array transduc...... leaves room for optimization. Despite the bias, the method has shown to work and produce reliable results, and 2D velocity estimates are provided within the entire color-box down to a depth of more than 100 mm making vector velocity imaging possible in the entire heart....

  1. Observations of three-dimensional needle deflection during insertion into soft tissue

    NARCIS (Netherlands)

    Jahya, Alex; Heijden, van der Ferdinand; Misra, Sarthak

    2012-01-01

    Accurate needle placement is important during percutaneous needle insertion procedures such as biopsy and brachytherapy. However, needle-tissue interactions may cause the needle to deviate from its intended path. In this paper, we have investigated the effects of insertion velocity, tip bevel angle

  2. THEORETICAL ANALYSIS ON THE DEPTH OF NEEDLE-INSERTION

    Institute of Scientific and Technical Information of China (English)

    LIN Wen-jian

    2005-01-01

    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.

  3. Should fine needle aspiration cytology in breast assessment be abandoned?

    Energy Technology Data Exchange (ETDEWEB)

    Litherland, Janet C

    2002-02-01

    Fine needle aspiration cytology (FNAC) has been used extensively in the U.K. for the diagnosis of breast lesions over the past 15 years. More recently, large gauge needle biopsy has been used to address many of the problems which have been encountered with fine needle aspiration. This paper reviews the evolution of the use of these procedures and the advantages and disadvantages of each. In considering whether to abandon the use of fine needle aspiration cytology in breast assessment, each individual unit should make a decision based upon their own audited results. However, even if FNAC is retained, it is important to be able to complement cytological diagnosis with core biopsy as there are indisputable advantages, e.g. in the diagnosis of mammographically detected microcalcification. As always, a multi-disciplinary approach is ultimately essential for effective patient management. Litherland, J.C. (2002)

  4. Should fine needle aspiration cytology in breast assessment be abandoned?

    Science.gov (United States)

    Litherland, Janet C

    2002-02-01

    Fine needle aspiration cytology (FNAC) has been used extensively in the U.K. for the diagnosis of breast lesions over the past 15 years. More recently, large gauge needle biopsy has been used to address many of the problems which have been encountered with fine needle aspiration. This paper reviews the evolution of the use of these procedures and the advantages and disadvantages of each. In considering whether to abandon the use of fine needle aspiration cytology in breast assessment, each individual unit should make a decision based upon their own audited results. However, even if FNAC is retained, it is important to be able to complement cytological diagnosis with core biopsy as there are indisputable advantages, e.g. in the diagnosis of mammographically detected microcalcification. As always, a multi-disciplinary approach is ultimately essential for effective patient management. PMID:11977938

  5. Warm-Needling Technique for Peripheral Facial Paralysis

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan-nian; ZHOU Jing; SHAO Ming-hai

    2007-01-01

    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.

  6. NEEDLE ANATOMY CHANGES WITH INCREASING TREE AGE IN DOUGLAS FIR

    Science.gov (United States)

    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...

  7. [Doctor HUANG Shi-ping's acupuncture with golden needles].

    Science.gov (United States)

    Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang

    2013-08-01

    Taking Doctor HUANG Shi-ping as the representative, the school of Huang's golden needle is based on Chinese martial art. Golden needles are adopted as main tool. Attaching great importance on the combination of acupuncture and moxibustioin, it is also characterized with penetrating needling with long needles. Through the development of three generations, it once outshone other schools in the field of acupuncture, and became famous all over the world. It made great contribution to the development of the course of acupuncture. However, with the development of the history, the form of acupuncture education as well as apparatus were all undergone an unified reform. Therefore, Doctor HUANG Shi-ping's acupuncture school be lost gradually.

  8. [Infection of a hip prosthesis after dry needling].

    Science.gov (United States)

    Steentjes, Koen; de Vries, Lieke M A; Ridwan, Ben U; Wijgman, A J Jurgen

    2016-01-01

    A 57-year-old patient presented to the orthopaedic department with hip pain 7 months after hip replacement and two weeks after dry needling by a physiotherapist. Dry needling is used by physiotherapists to treat pain and stiffness. In the Netherlands, there are no clear guidelines or contra-indications described for this treatment. The surgical scar of our patient showed signs of inflammation for which debridement and irrigation were performed. Tissue samples showed positive bacterial cultures and the patient was treated with antibiotics. One week after completing this treatment, the infection returned. Debridement and irrigation were repeated and antibiotic treatment was recommenced. Three months later, the patient showed no signs of infection with the prosthesis still in situ. Although there is no strong evidence for a causal relationship between dry needling and the infection, dry needling should be used carefully in patients with a joint replacement, due to the increased risk of infection. PMID:26786794

  9. Ralph L. Huber, DMD: forgotten inventor of the "Tuohy" needle.

    Science.gov (United States)

    Lubisich, Josef W

    2004-07-01

    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. Simple method for measuring vibration amplitude of high power airborne ultrasonic transducer: using thermo-couple.

    Science.gov (United States)

    Saffar, Saber; Abdullah, Amir

    2014-03-01

    Vibration amplitude of transducer's elements is the influential parameters in the performance of high power airborne ultrasonic transducers to control the optimum vibration without material yielding. The vibration amplitude of elements of provided high power airborne transducer was determined by measuring temperature of the provided high power airborne transducer transducer's elements. The results showed that simple thermocouples can be used both to measure the vibration amplitude of transducer's element and an indicator to power transmission to the air. To verify our approach, the power transmission to the air has been investigated by other common method experimentally. The experimental results displayed good agreement with presented approach. PMID:24246149

  11. Determination of the response time of pressure transducers using the direct method

    International Nuclear Information System (INIS)

    The available methods to determine the response time of nuclear safety related pressure transducers are discussed, with emphasis to the direct method. In order to perform the experiments, a Hydraulic Ramp Generator was built. The equipment produces ramp pressure transients simultaneously to a reference transducer and to the transducer under test. The time lag between the output of the two transducers, when they reach a predetermined setpoint, is measured as the time delay of the transducer under test. Some results using the direct method to determine the time delay of pressure transducers (1 E Class Conventional) are presented. (author). 18 refs, 35 figs, 12 tabs

  12. Evaluation of Efficacy of Four Laparoscopic Needle Drivers

    OpenAIRE

    Ramani, Anup P.; Braasch, Matthew; Botnaru, Andrei; Lavers, Ann; Herrera, Shannon; Pedro, Renato Nardi; Monga, Manoj

    2008-01-01

    Introduction: To evaluate the impact of needle driver design on laparoscopic suturing skills by experts and novices. Methods: Three experienced laparoscopic surgeons and 3 novice junior residents were asked to perform a fixed set of suturing tasks in a laparoscopic pelvic-trainer. The laparoscopic needle drivers compared were (1) the Ethicon driver (E 705R), (2) Karl Storz (KS) pistol grip (26173 KC), (3) KS finger grip (26167 SK), and (4) KS palm grip (26173 ML). Times were recorded for each...

  13. Fine Needle Aspiration Cytology of Pediatric Thyroid Nodules

    OpenAIRE

    Ayper KAÇAR; İrem PAKER; Gülşah KABAÇAM BAYRAM; Fatma DEMİREL; Şenel, Emrah; Murat KIZILGÜN

    2010-01-01

    Objective: The objectives were to evaluate fine needle aspiration cytology results of 39 pediatric patients, and the pathologies that cause childhood thyroid nodules, and to review the literature on the subject.Material and Method: Thyroid fine needle aspiration cytology results of 39 pediatric patients were retrospectively reviewed. Associated diseases, thyroid functions, anti-thyroid antibody levels, ultrasonographic findings and number of nodules were also evaluated.Results: The vast major...

  14. Enterobacter aerogenes Needle Stick Leads to Improved Biological Management System

    Energy Technology Data Exchange (ETDEWEB)

    Johanson, Richard E.

    2004-08-01

    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.

  15. A Needle Penetrating the Stomach Cavity after Acupuncture

    OpenAIRE

    Lee, Sin Won; Ahn, Ji Yong; Choi, Won Jung; Kim, Eun Jin; Bae, Seung-Hyeon; Choi, Yun Sik; Jung, Hwoon-Yong; Kim, Jin-Ho

    2014-01-01

    Although acupuncture is known as a safe procedure that is widely used in many countries, complications including infection, hemorrhage, hematoma, pneumothorax, nerve damage, and cardiac tamponade have been reported. A needle penetrating the stomach after acupuncture, however, is very rare. Here, we report the case of 47-year-old woman who experienced abdominal pain 2 days after receiving acupuncture. Upper gastrointestinal endoscopy identified an approximately 2.5-cm long needle in the poster...

  16. Clinical Application of Movement-needling Technique: Stiff Neck

    Institute of Scientific and Technical Information of China (English)

    LIU Yan

    2005-01-01

    @@ 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.

  17. ImaGiNe-S: Imaging Guided Needle Simulation

    OpenAIRE

    Bello, Fernando; Bulpitt, Andrew; Gould, Derek A.; Holbrey, Richard; Hunt, Carrie; How, Thien; John, Nigel W; Johnson, Sheena; Phillips, Roger; Sinha, Amrita; Vidal, Franck P; Villard, Pierre-Frédéric; Woolnough, Helen; Zhang, Yan

    2009-01-01

    We present an integrated system for training visceral needle puncture procedures. Our aim is to provide a cost effective and validated training tool that uses actual patient data to enable interventional radiology trainees to learn how to carry out image-guided needle puncture. The input data required is a computed tomography scan of the patient that is used to create the patient specific models. Force measurements have been made on real tissue and the resulting data is incorporated into the ...

  18. Developing An Immersive Ultrasound Guided Needle Puncture Simulator

    OpenAIRE

    Vidal, Franck P; Villard, Pierre-Frederic; Holbrey, Richard; John, Nigel W; Bello, Fernando; Bulpitt, Andrew; Gould, Derek A.

    2009-01-01

    We present an integrated system for training ultrasound guided needle puncture. Our aim is to provide a cost effective and validated training tool that uses actual patient data to enable interventional radiology trainees to learn how to carry out image-guided needle puncture. The input data required is a computed tomography scan of the patient that is used to create the patient specific models. Force measurements have been made on real tissue and the resulting data is incorporated into the si...

  19. Endoscopic and endosonography guided fine-needle aspiration.

    Science.gov (United States)

    Antillon, M R; Chang, K J

    2000-10-01

    Endoscopic ultrasound-guided fine-needle aspiration is emerging as the preferred technique for the cytologic diagnosis of various gastrointestinal lesions. This technique may not be routinely available, but there is still a role for endoscopic or endoscopic ultrasound-assisted fine-needle aspiration. This article provides an overview of the evolution of these various techniques and discusses the advantages, disadvantages, indications, and contraindications of each. PMID:11036536

  20. Cantilever deflection measurement and actuation by an nterdigitated transducer

    NARCIS (Netherlands)

    Strambini, E.; Piazza, V.; Pingue, P.; Biasiol, G.; Sorba, L.; Beltram, F.

    2010-01-01

    A scheme that allows all-electrical high-bandwidth readout of a cantilever deflection by means of an integrated interdigitated transducer is presented. The present approach takes advantage of the piezoelectricity of the chosen cantilever substrate material to generate and detect surface-acoustic-wav

  1. Linear synthetic aperture focusing using ultrasonic contact transducers

    International Nuclear Information System (INIS)

    Synthetic aperture processing performed on linear scans with contact ultrasonic transducers can yield useful improvements in lateral resolution of deeply buried defects. Degradation in resolution caused by adverse surface conditions can be minimised by a simple pre-processing normalisation technique. (author)

  2. Characterization of HIFU transducers designed for sonochemistry application: Acoustic streaming.

    Science.gov (United States)

    Hallez, L; Touyeras, F; Hihn, J-Y; Bailly, Y

    2016-03-01

    Cavitation distribution in a High Intensity Focused Ultrasound sonoreactors (HIFU) has been extensively described in the recent literature, including quantification by an optical method (Sonochemiluminescence SCL). The present paper provides complementary measurements through the study of acoustic streaming generated by the same kind of HIFU transducers. To this end, results of mass transfer measurements (electrodiffusional method) were compared to optical method ones (Particle Image Velocimetry). This last one was used in various configurations: with or without an electrode in the acoustic field in order to have the same perturbation of the wave propagation. Results show that the maximum velocity is not located at the focal but shifted near the transducer, and that this shift is greater for high powers. The two cavitation modes (stationary and moving bubbles) are greatly affect the hydrodynamic behavior of our sonoreactors: acoustic streaming and the fluid generated by bubble motion. The results obtained by electrochemical measurements show the same low hydrodynamic activity in the transducer vicinity, the same shift of the active focal toward the transducer, and the same absence of activity in the post-focal axial zone. The comparison with theoretical Eckart's velocities (acoustic streaming in non-cavitating media) confirms a very high activity at the "sonochemical focal", accounted for by wave distortion, which induced greater absorption coefficients. Moreover, the equivalent liquid velocities are one order of magnitude larger than the ones measured by PIV, confirming the enhancement of mass transfer by bubbles oscillation and collapse close to the surface, rather than from a pure streaming effect.

  3. Finite element analysis of underwater capacitor micromachined ultrasonic transducers.

    Science.gov (United States)

    Roh, Yongrae; Khuri-Yakub, Butrus T

    2002-03-01

    A simple electro-mechanical equivalent circuit model is used to predict the behavior of capacitive micromachined ultrasonic transducers (cMUT). Most often, cMUTs are made in silicon and glass plates that are in the 0.5 mm to 1 mm range in thickness. The equivalent circuit model of the cMUT lacks important features such as coupling to the substrate and the ability to predict cross-talk between elements of an array of transducers. To overcome these deficiencies, a flnite element model of the cMUT is constructed using the commercial code ANSYS. Calculation results of the complex load impedance seen by single capacitor cells are presented, then followed by a calculation of the plane wave real load impedance seen by a parallel combination of many cells that are used to make a transducer. Cross-talk between 1-D array elements is found to be due to two main sources: coupling through a Stoneley wave propagating at the transducer-water interface and coupling through Lamb waves propagating in the substrate. To reduce the cross-talk level, the effect of structural variations of the substrate are investigated, which includes a change of its thickness and etched trenches or polymer walls between array elements. PMID:12322877

  4. Enhancing endosomal escape of transduced proteins by photochemical internalisation.

    Directory of Open Access Journals (Sweden)

    Kevin Mellert

    Full Text Available Induced internalisation of functional proteins into cultured cells has become an important aspect in a rising number of in vitro and in vivo assays. The endo-lysosomal entrapment of the transduced proteins remains the major problem in all transduction protocols. In this study we compared the efficiency, cytotoxicity and protein targeting of different commercially available transduction reagents by transducing a well-studied fluorescently labelled protein (Atto488-bovine serum albumin into cultured human sarcoma cells. The amount of internalised protein and toxicity differed between the different reagents, but the percentage of transduced cells was consistently high. Furthermore, in all protocols the signals of the transduced Atto488-BSA were predominantly punctual consistent with an endosomal localisation. To overcome the endosomal entrapment, the transduction protocols were combined with a photochemical internalisation (PCI treatment. Using this combination revealed that an endosomal disruption is highly effective in cell penetrating peptide (CPP mediated transduction, whereas lipid-mediated transductions lead to a lower signal spreading throughout the cytosol. No change in the signal distribution could be achieved in treatments using non-lipid polymers as a transduction reagent. Therefore, the combination of protein transduction protocols based on CPPs with the endosomolytic treatment PCI can facilitate protein transduction experiments in vitro.

  5. Fabrication and integration of permanent magnet materials into MEMS transducers

    Science.gov (United States)

    Wang, Naigang

    Microscale permanent magnets (PM) are a key building block for magnetically based microelectromechanical systems (MEMS), such as sensors, actuators, and energy converters. However, the inability to concurrently achieve good magnetic properties and an integrated magnet fabrication process hinders the development of magnetic MEMS. To address this need, this dissertation develops methods for wafer-level microfabrication of thick (10--500+ microm), high-performance, permanent magnets using low-temperature (electrodynamic transducer prototypes. A cantilever-type microtransducer achieves a 2.7 microm vertical deflection at a driving current of 5.5 mArms at 100 Hz. A piston-type transducer with elastomeric membrane obtains a 2.2 microm vertical displacement at a driving current of 670 mArms at 200 Hz. These devices demonstrate the integrability of wax-bonded Nd-Fe-B powder magnets into microscale electromechanical transducers. Electromechanical lumped element models are then developed for the piston-type electrodynamic actuators. The models enable prediction of the device performance as an electroacoustic actuator (microspeaker) and as a mechanoelectrical generator (vibrational energy harvester). Then, both the acoustic and energy harvesting performance of the prototype transducers are experimentally measured to verify the LEM models. The validated models provide a design tool for further design and development of these types of micromagnetic MEMS devices.

  6. High Temperature Ultrasonic Transducers : Material Selection and Testing

    Science.gov (United States)

    Bar-Cohen, Yoseph; Bruno, Alessandro

    2012-01-01

    The task of my two-months internship was to test different materials to be used to build an high temperature transducer, to develop some prototypes and to test their performance, to assess the reliability of commercial product rated for such a temperature, as well as to collaborate in developing the signal processing code to measure the condensed water levels.

  7. Multilayer piezoelectric transducer models combined with Field II

    DEFF Research Database (Denmark)

    Bæk, David; Willatzen, Morten; Jensen, Jørgen Arendt

    2012-01-01

    One-dimensional and three-dimensional axisymmetric transducer model have been compared to determine their feasibility to predict the volt-to-surface impulse response of a circular Pz27 piezoceramic disc. The ceramic is assumed mounted with silver electrodes, bounded at the outer circular boundary...

  8. Multilayer pieozoelectric transducer models combined with Field II

    DEFF Research Database (Denmark)

    Bæk, David; Willatzen, Morten

    2009-01-01

    boundary with a polymer ring, and submerged into water. The transducer models are developed to account for any external electrical loading impedance in the driving circuit. The models are adapted to calculate the impulse surface acceleration needed by the Field II software in predicting pressure pulses at...

  9. Breast ultrasound tomography with two parallel transducer arrays

    Science.gov (United States)

    Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Gao, Kai; Intrator, Miranda; Hanson, Kenneth

    2016-03-01

    Breast ultrasound tomography is an emerging imaging modality to reconstruct the sound speed, density, and ultrasound attenuation of the breast in addition to ultrasound reflection/beamforming images for breast cancer detection and characterization. We recently designed and manufactured a new synthetic-aperture breast ultrasound tomography prototype with two parallel transducer arrays consisting of a total of 768 transducer elements. The transducer arrays are translated vertically to scan the breast in a warm water tank from the chest wall/axillary region to the nipple region to acquire ultrasound transmission and reflection data for whole-breast ultrasound tomography imaging. The distance of these two ultrasound transducer arrays is adjustable for scanning breasts with different sizes. We use our breast ultrasound tomography prototype to acquire phantom and in vivo patient ultrasound data to study its feasibility for breast imaging. We apply our recently developed ultrasound imaging and tomography algorithms to ultrasound data acquired using our breast ultrasound tomography system. Our in vivo patient imaging results demonstrate that our breast ultrasound tomography can detect breast lesions shown on clinical ultrasound and mammographic images.

  10. Nonlinear behaviour of power ultrasonic transducers for food processing

    Science.gov (United States)

    Riera, E.; Cardoni, A.; Acosta, V. M.; Gallego-Juárez, J. A.

    2012-05-01

    Power ultrasonic systems at laboratory and semi-industrial scale are currently investigated to demonstrate the suitability of ultrasonic waves of high-intensity to industrial applications. It has been shown that intense ultrasonic fields trigger a series of mechanisms in the irradiated media that may enhance and/or accelerate a variety of processes in the food sector. Ultrasonic radiators driven by piezoelectric vibrators have been specifically developed for assisting in drying and extraction operations. Successful industrial scale-up of such tuned systems significantly depends on the control of their nonlinear vibration behaviour at high operational power levels. In this paper we investigated experimentally the nonlinear dynamics of two power ultrasonic transducers: a grooved-plate transducer and a cylindrical radiator transducer. Nonlinear mechanisms affecting the dynamic behaviour of both assemblies such as the appearance of harmonics, combination of resonances, or modal interactions, and response saturation are presented. In particular, energy transfers among system modes that may produce the excitation of nontuned resonant frequencies causing heating, noise and even failures of the transducers are identified and characterised.

  11. Candle soot nanoparticles-polydimethylsiloxane composites for laser ultrasound transducers

    Science.gov (United States)

    Chang, Wei-Yi; Huang, Wenbin; Kim, Jinwook; Li, Sibo; Jiang, Xiaoning

    2015-10-01

    Generation of high power laser ultrasound strongly demands the advanced materials with efficient laser energy absorption, fast thermal diffusion, and large thermoelastic expansion capabilities. In this study, candle soot nanoparticles-polydimethylsiloxane (CSNPs-PDMS) composite was investigated as the functional layer for an optoacoustic transducer with high-energy conversion efficiency. The mean diameter of the collected candle soot carbon nanoparticles is about 45 nm, and the light absorption ratio at 532 nm wavelength is up to 96.24%. The prototyped CSNPs-PDMS nano-composite laser ultrasound transducer was characterized and compared with transducers using Cr-PDMS, carbon black (CB)-PDMS, and carbon nano-fiber (CNFs)-PDMS composites, respectively. Energy conversion coefficient and -6 dB frequency bandwidth of the CSNPs-PDMS composite laser ultrasound transducer were measured to be 4.41 × 10-3 and 21 MHz, respectively. The unprecedented laser ultrasound transduction performance using CSNPs-PDMS nano-composites is promising for a broad range of ultrasound therapy applications.

  12. Nonlinear Dynamic Modeling of Langevin-Type Piezoelectric Transducers

    Directory of Open Access Journals (Sweden)

    Nicolás Peréz Alvarez

    2015-11-01

    Full Text Available Langevin transducers are employed in several applications, such as power ultrasound systems, naval hydrophones, and high-displacement actuators. Nonlinear effects can influence their performance, especially at high vibration amplitude levels. These nonlinear effects produce variations in the resonant frequency, harmonics of the excitation frequency, in addition to loss of symmetry in the frequency response and “frequency domain hysteresis”. In this context, this paper presents a simplified nonlinear dynamic model of power ultrasound transducers requiring only two parameters for simulating the most relevant nonlinear effects. One parameter reproduces the changes in the resonance frequency and the other introduces the dependence of the frequency response on the history of the system. The piezoelectric constitutive equations are extended by a linear dependence of the elastic constant on the mechanical displacement amplitude. For introducing the frequency hysteresis, the elastic constant is computed by combining the current value of the mechanical amplitude with the previous state amplitude. The model developed in this work is applied for predicting the dynamic responses of a 26 kHz ultrasonic transducer. The comparison of theoretical and experimental responses, obtained at several input voltages around the tuned frequency, shows a good agreement, indicating that the model can accurately describe the transducer nonlinear behavior.

  13. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  14. A Novel Rotary Piezoelectric Motor Using First Bending Hybrid Transducers

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    2015-08-01

    Full Text Available We report a novel rotary piezoelectric motor using bending transducers in this work. Three transducers are used to drive a disk-shaped rotor together by the elliptical movements of their driving tips; these motions are produced by the hybrid of two first bending vibration modes. The proposed piezoelectric transducer has a simple structure as it only contains an aluminum alloy beam and four pieces of PZT plates. Symmetrical structure is the only necessary condition in the design process as it will ensure the resonance frequencies of the two orthogonal first bending modes are equal. Transducers with first bending resonance frequency of about 53 kHz were fabricated and assembled into a rotary motor. The proposed motor exhibits good performance on speed and torque control. Under a working frequency of 53.2 kHz, the maximum no-load speed and the maximum torque of the prototype are tested to be 53.3 rpm and of 27 mN·m.

  15. Nursing and safety of silver needle diathermy treating ankylosing spondylitis.

    Science.gov (United States)

    Ning, Huaxiu; Wang, Yun; Yuan, Yiwen; Ning, Huaying

    2015-03-01

    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.

  16. SILICON NEEDLE ARRAY ON FLEXIBLE SUBSTRATE FOR FLUID TRANSFER

    Institute of Scientific and Technical Information of China (English)

    MA Bin; GAN Zhiyin; LIU Sheng

    2006-01-01

    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.

  17. Needle stick injury in a radiology department: a decade analysis

    International Nuclear Information System (INIS)

    Objectives: To determine the frequency of needle stick injury in health care workers of radiology department. Study type, settings and duration: Cross sectional, observational study conducted at the Radiology department of Aga Khan University hospital from January 2000 to May 2010. Subject and Methods: All self-reported needle stick injuries data of Health care workers of radiology department was recorded. The personnel involved (Radiologist, resident, radiographer, nurses etc), area of working and the causes of injury were identified including the procedural or post procedural details. Patient's status of hepatitis or blood borne infection was also noted. Data was recorded and analyzed in Excel worksheet. Results: A total of 55 health workers reported needle stick injuries at all sections of radiology departments with maximum number needle stick injuries at general radiography, fluoroscopy and IVP section. Radiographers and radiology residents received the maximum number of injuries. Major cause of injury was cannulation however, many injuries occurred during disposing or handling of bin. In majority of cases the patients were not infected with any known blood borne infections. Conclusions: Doctors and nurses get needle-stick injuries while carrying out clinical procedures, while, ancillary staff get infected post procedure during disposal of garbage. Policy message: Good occupational health and safety practices must be promoted to all staff. Safer disposal of needles is an important area where practice and procedure needs to be carefully reviewed. It is necessary to undertake a risk assessment, to offer counseling and Post Exposure Prophylaxis and treatment where necessary. (author)

  18. Neuromuscular Damage and Repair after Dry Needling in Mice

    Directory of Open Access Journals (Sweden)

    Ares Domingo

    2013-01-01

    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.

  19. Needle core biopsy for breast lesions: An audit of 467 needle core biopsies

    Directory of Open Access Journals (Sweden)

    Selvi Radhakrishna

    2013-01-01

    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

  20. Micro-needle electro-tactile display.

    Science.gov (United States)

    Tezuka, Mayuko; Kitamura, Norihide; Miki, Norihisa

    2015-08-01

    Haptic feedback is strongly demanded for high-precision robot-assisted surgery and teleoperation. The haptic feedback consists of force and tactile feedback, however tactile feedback has been little studied and the size and weight of the system poses challenges for practical applications. In this paper we propose a sheet-type wearable electro-tactile display which provides tactile sensations to the user as the feedback at a low voltage and power consumption. The display possesses needle-shaped electrodes, which can penetrate through the high-impedance stratum corneum. We developed the fabrication process and, as the first step, we investigated the tactile sensation that can be created to the fingertip by the display. Rough and smooth surfaces were successfully presented to the user. Then, we characterized the tactile display when used on the forearm, in particular, with respect to the spatial resolution. These tactile displays can be used to inform the user of the surface property of the parts of interest, such as tumor tissues, and to guide him in the manipulation of surgery robots. PMID:26737606

  1. Hollow needle cataract aspiration in antiquity.

    Science.gov (United States)

    Pérez-Cambrodí, Rafael J; Ascaso, Francisco J; Diab, Fathi; Alzamora-Rodríguez, Antonio; Grzybowski, Andrzej

    2015-12-01

    The dislocation of the crystalline lens or couching technique was the predominant procedure to surgically remove cataracts until the 18th century A.D. However, in the Middle Ages, some Arab physicians tried to aspirate the opaque lens by means of a glass tube following a paracentesis. Some literary sources attributed the origins of this technique to Antyllus of Alexandria, a Greek surgeon who lived in the 2nd century A.D. in the Roman Empire. Nevertheless, this statement remains unclear and is probably the consequence of posterior interpretations or incorrect translations of the manuscripts. In recent years, the discovery of the hollow needles from Montbellet (France) and Viladamat (Spain), in archaeological settlements dated between the 1st century and 3rd century A.D., has reopened the possibility of cataract extraction as an option in the surgical management of soft cataracts in the antiquity. In any case, these findings are exceptional, and thus, probably this technique was not widely practised and very likely disparaged by the medical community. PMID:26385516

  2. Fine needle aspiration cytology in leprosy

    Directory of Open Access Journals (Sweden)

    Prasad PVS

    2008-01-01

    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.

  3. 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)

    1999-06-01

    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.

  4. Susuks (charm needles) in the craniofacial region

    International Nuclear Information System (INIS)

    We conducted a study to determine the numbers of susuks (charm needles) and their distribution in the craniofacial region of susuk wearers, and the sex, racial affiliation, and age of the wearers. In addition, we sought to determine whether the presence of susuks posed any potential hazard to patients undergoing magnetic resonance imaging (MRI). We studied various radiographs of 33 susuk wearers (age range, 33-69 years) and investigated the most common sites of insertion in the craniofacial region. A susuk was also suspended inside a 1.5-T MRI machine to determined whether it was attracted by the machine's magnet. The largest number of susuks that we observed in the craniofacial region was 39 pins, and susuks were particularly numerous in Malay Muslim women. Other sites with susuks were the maxillofacial region (except the temporomandibular region) and the forehead. The susuks showed no ferromagnetic characteristics. As susuks are made from gold, they are generally biocompatible with human tissue and do not cause problems to their wearers. Gold and the other minor metal constituents found in susuks have no ferromagnetic characteristics and therefore pose no hazard to patients undergoing MRI. (author)

  5. Nuclear Radiation Tolerance of Single Crystal Aluminum Nitride Ultrasonic Transducer

    Science.gov (United States)

    Reinhard, Brian; Tittmann, Bernhard R.; Suprock, Andrew

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models, (Rempe et al., 2011; Kazys et al., 2005). These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The irradiation is also supported by a multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET ASI) program. The results from this irradiation, which started in February 2014, offer the potential to enable the development of novel radiation tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. Hence, results from this irradiation offer the potential to bridge the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the

  6. Lithium niobate transducers for MRI-guided ultrasonic microsurgery.

    Science.gov (United States)

    Kotopoulis, Spiros; Wang, Han; Cochran, Sandy; Postema, Michiel

    2011-08-01

    Focused ultrasound surgery (FUS) is usually based on frequencies below 5 MHz-typically around 1 MHz. Although this allows good penetration into tissue, it limits the minimum lesion dimensions that can be achieved. In this study, we investigate devices to allow FUS at much higher frequencies, in principle, reducing the minimum lesion dimensions. Furthermore, FUS can produce deep-sub-millimeter demarcation between viable and necrosed tissue; high-frequency devices may allow this to be exploited in superficial applications which may include dermatology, ophthalmology, treatment of the vascular system, and treatment of early dysplasia in epithelial tissue. In this paper, we explain the methodology we have used to build high-frequency high-intensity transducers using Y-36°-cut lithium niobate. This material was chosen because its low losses give it the potential to allow very-high-frequency operation at harmonics of the fundamental operating frequency. A range of single-element transducers with center frequencies between 6.6 and 20.0 MHz were built and the transducers' efficiency and acoustic power output were measured. A focused 6.6-MHz transducer was built with multiple elements operating together and tested using an ultrasound phantom and MRI scans. It was shown to increase phantom temperature by 32°C in a localized area of 2.5 x 3.4 mm in the plane of the MRI scan. Ex vivo tests on poultry tissue were also performed and shown to create lesions of similar dimensions. This study, therefore, demonstrates that it is feasible to produce high-frequency transducers capable of high-resolution FUS using lithium niobate. PMID:21859576

  7. Effect of stimuli, transducers and gender on acoustic change complex

    Directory of Open Access Journals (Sweden)

    Hemanth N. Shetty

    2012-08-01

    Full Text Available The objective of this study was to investigate the effect of stimuli, transducers and gender on the latency and amplitude of acoustic change complex (ACC. ACC is a multiple overlapping P1-N1-P2 complex reflecting acoustic changes across the entire stimulus. Fifteen males and 15 females, in the age range of 18 to 25 (mean=21.67 years, having normal hearing participated in the study. The ACC was recorded using the vertical montage. The naturally produced stimuli /sa/ and /si/ were presented through the insert earphone/loud speaker to record the ACC. The ACC obtained from different stimuli presented through different transducers from male/female participants were analyzed using mixed analysis of variance. Dependent t-test and independent t-test were performed when indicated. There was a significant difference in latency of 2N1 at the transition, with latency for /sa/ being earlier; but not at the onset portions of ACC. There was no significant difference in amplitude of ACC between the stimuli. Among the transducers, there was no significant difference in latency and amplitude of ACC, for both /sa/ and /si/ stimuli. Female participants showed earlier latency for 2N1 and larger amplitude of N1 and 2P2 than male participants, which was significant. ACC provides important insight in detecting the subtle spectral changes in each stimulus. Among the transducers, no difference in ACC was noted as the spectra of stimuli delivered were within the frequency response of the transducers. The earlier 2N1 latency and larger N1 and 2P2 amplitudes noticed in female participants could be due to smaller head circumference. The findings of this study will be useful in determining the capacity of the auditory pathway in detecting subtle spectral changes in the stimulus at the level of the auditory cortex.

  8. Percutaneous transthoracic cutting needle biopsy of pulmonary lesions: comparison of the use of 18 and 20 gauge needles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chun Chang; Jin, Gong Yong; Han, Young Min; Park, Hak Hun; Kwon, Keun Sang [Chonbuk National University Hospital, Medical School, Research Institute of Clinical Medicine, Jeonju(Korea, Republic of)

    2008-05-15

    We evaluated the usefulness of a CT guided percutaneous transthoracic cutting needle biopsy (PCNB) using a 20 gauge (G) needle for pulmonary lesions after a comparison with the use of an 18 G needle for diagnostic accuracy and complications. From August 2005 to July 2007, 433 patients underwent a CT guided PCNB. A total of 191 patients were excluded from the study as these patients had benign lesions seen after PCNB, but did not receive a confirmation biopsy or undergo follow-up (> 1 year). We evaluated the diagnostic accuracy for the use of PCNB using the Chi-squared test and analyzed which factors (location and size of lesions, diameter of the needle, distance between the pleura and lesions, presence or not of emphysema) were related to occurrence of a pneumothorax after PCNB using a multi-variant regression test. The diagnostic accuracy for malignant lesions with the use of an 18 G and a 20 G needle were 95.4% and 97%, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the use of an 18 G needle were 95.7%, 100%, 100%, and 91.6%. The sensitivity, specificity, PPV, and NPV were 97.8%, 100%, 100%, and 95.0% for the use of a 20 G needle. A pneumothorax occurred in 5.5% (24/433) of the cases and was closely related to the distance from the pleura to the lesions. CT guided PCNB with the use of a 20 gauge needle provided good diagnostic accuracy and the procedure is safe to perform.

  9. Comparison of Fine Needle Aspiration and Fine Needle Nonaspiration Cytology of Thyroid Nodules: A Meta-Analysis

    OpenAIRE

    Hongming Song; Chuankui Wei; Dengfeng Li; Kaiyao Hua; Jialu Song; Niraj Maskey; Lin Fang

    2015-01-01

    Background. Fine needle aspiration cytology (FNAC) and fine needle nonaspiration cytology (FNNAC) are useful cost-effective techniques for preoperatively assessing thyroid lesions. Both techniques have advantages and disadvantages, and there is controversy over which method is superior. This meta-analysis was performed to evaluate the differences between FNAC and FNNAC for diagnosis of thyroid nodules. Methods. Primary publications were independently collected by two reviewers from PubMed, We...

  10.  A Comparative Study on Fine Needle Aspiration Cytology versus Fine Needle Capillary Cytology in Thyroid Nodules

    OpenAIRE

    Prathvi Shetty; Divakar Shenoy; P. Sathyamoorthy Aithala; Celine George; Hilda Fernandes; Lobo, Geover J.; Leo F. Tauro

    2012-01-01

     Objectives: Fine needle aspiration cytology (FNAC/FNA) is the primary investigation for thyroid nodules. Fine needle capillary cytology (FNCC/FNC) is an alternative technique not commonly used, though it is easy to perform. Both the techniques have their own advantages and disadvantages. This study aims to compare these two cytological techniques for better specimen and cytological diagnosis.Methods: This prospective study was conducted on 50 patients attending the FR Muller Medical College ...

  11. Impact of Needle Diameter on Long-Term Dry Needling Treatment of Chronic Lumbar Myofascial Pain Syndrome

    Science.gov (United States)

    Wang, Gang; Gao, Qian; Li, Jun; Tian, Yuling; Hou, Jingshan

    2016-01-01

    ABSTRACT Objective To investigate the impact of diameter of needles on the effect of dry needling treatment of chronic lumbar myofascial pain syndrome. Design Forty-eight patients with chronic lumbar myofascial pain syndrome were randomly allocated to 3 groups. They received dry needling with needles of diameter 0.25 (group A), 0.5 (group B), and 0.9 mm (group C). Visual analog scale evaluation and health survey were conducted at baseline and 3 months after the treatment. Results Visual analog scale scores were significantly different in all groups from baseline to 3 months. Visual analog scale scores at 3 months showed differences between group C and the other 2 groups. When baseline and 3 months after treatment (0 day and 3 months) in each of the 3 groups was compared, there was a difference between group C and group B. The Short Form (36) Health Survey scores from baseline to 3 months were different within the treatment groups. Conclusions Visual analog scale score evaluations at 3 months showed efficacy in all groups. Results of 3 months showed that efficacy of treatment with larger needles (0.9-mm diameter) was better than that of smaller ones (0.5-mm diameter). The Short Form (36) Health Survey scores at 3 months indicated that treatments with needles of varying diameters were all effective, and when the results of 3 months were compared, there was no difference between the 3 groups. PMID:27333534

  12. Six-Axis Force-Torque Transducer for Mars 2018 Mission Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A transducer element that is hearty enough for a Mars lander mission needs to be developed so that a six-axis force and torque transducer is possible. The technical...

  13. 300 CASES OF HYPERPLASIA OF MAMMARY GLANDS TREATED WITH RED-HOT NEEDLE PLUS FILIFORM NEEDLE

    Institute of Scientific and Technical Information of China (English)

    蔡志红; 吴英; 付波; 贺普仁

    2003-01-01

    Clinical observations on 300 cases of hyperplasia of mammary glands (group A) treated by red-hot needle plus filiform needle are reported in the present study. "Ashi" points were used as the main acupoints. For comparison, other 300 cases (group B) were treated with routine acupuncture method, and Rugen (ST 18) was used as the main acupoint. In addition, other auxiliary acupoints were supplemented in the light of the concrete syndromes in these two groups. The treatment was given once daily, with 10 sessions being a therapeutic course. Of the 300 cases in group A, 240 were clinically cured, amounting to 80%; 58 were effective, amounting to 19.3%; 2 were failed, with a total effective rate of 99.3%. Of the 300 cases in group B, 113 were clinically cured, 165 effective, 22 were failed, with a total effective rate of 92.7%. The therapeutic effect of group A is significantly superior to that of group B (P<0.05).

  14. Eddy Current Transducer Dedicated for Sigma Phase Evaluation in Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Grzegorz Psuj

    2012-01-01

    Full Text Available The paper describes a new transducer dedicated for evaluation of a duplex stainless steel (DSS. Different phases which exist in DSS have influence on mechanical as well as on electrical properties. Therefore, an eddy current transducer was utilized. In order to achieve high sensitivity, a differential type of the transducer was selected. The performance of the transducer was verified by utilizing the samples which had a different amount of sigma phase.

  15. Fine needle aspiration biopsy of fibromatoses.

    Science.gov (United States)

    Raab, S S; Silverman, J F; McLeod, D L; Benning, T L; Geisinger, K R

    1993-01-01

    Fibromatoses form a spectrum of clinicopathologic entities characterized by the infiltrative proliferation of fibroblasts that lack malignant cytologic features. Fibromatoses present as nodular soft tissue masses almost anywhere in the body and thus are often amenable to fine needle aspiration (FNA). This report describes the FNA cytologic findings of fibromatosis in six patients ranging in age from 7 1/2 weeks to 36 years. Two of the lesions arose in the abdominal wall (musculoaponeurotic fibromatosis or extra-abdominal desmoid), and one each involved the plantar surface (Ledderhose's disease), the shoulder and the sternocleidomastoid muscle (Fibromatosis coli). The FNA of the shoulder was initially interpreted as nodular fasciitis due to the clinical presentation of a rapidly growing mass; an aspirate from the deep musculoaponeurotic region was believed to reveal a low grade sarcoma. The FNA diagnosis of musculoaponeurotic fibromatosis in a patient with familial polyposis coli suggested the diagnosis of Gardner's syndrome. Cytologically the aspirates consisted of groups of loosely cohesive, bland-appearing, spindle-shaped cells having oval to elongated nuclei and cytoplasmic tags. Individual spindle cells and rare inflammatory cells were also present. The aspirate of fibromatosis coli also contained degenerating skeletal muscle cells. Tissue confirmation was obtained in four cases. We believe that FNA is a useful procedure for the initial and recurrent diagnosis of fibromatoses and in the separation of fibromatoses from other benign and malignant soft tissue lesions. A discussion of other entities that enter into the cytologic differential diagnosis, such as mesenchymal repair, fasciitis and spindle cell types of sarcoma, is presented. From our experience we believe that the clinicopathologic features can suggest the diagnosis of fibromatosis, but histologic confirmation is recommended.

  16. Syringe and needle exchange programs: Part I.

    Science.gov (United States)

    Schwartz, R H

    1993-03-01

    Syringe and needle exchange (SANE) programs appear to be a pragmatic approach to reducing the rising incidence of human immunodeficiency virus (HIV) infection among intravenous drug users (IVDUs). One purported indication of the effectiveness of SANE programs is lower prevalence rates of cases of AIDS or of HIV seropositivity in cities with SANE programs than in cities without such programs. In each positive comparison cited, however, the lower levels of HIV seropositivity were already present before the establishment of SANE programs. A second indicator of SANE effectiveness is a reduction in prevalence of hepatitis B in SANE program participants. Multiple factors working in concert, not simply the SANE programs, however, account for such progress; such factors include reductions in sharing of uncleaned injection equipment; legal exchange or sale of syringes at pharmacies; regular rinsing of used "works" with bleach; and epidemiologic fluctuations in the prevalence or a saturation level of the hepatitis B virus in IVDUs. A third indicator of the value of SANE programs is that they enable some otherwise unreachable IVDUs to make contact with a social or health facility. SANE programs do not facilitate the induction of new IVDUs or increase the frequency of injection by older addicts. From 60% to 90% of SANE attenders will return borrowed used injection equipment. Most participants reported that they reduced the frequency of lending or borrowing unclean injection equipment. Counterbalancing the above, SANE programs attract only a minority of all IVDUs in most cities, and they fail to attract the youngest subset of IVDUs. The attrition rate is high; only a small percentage of attenders remain with the program for more than a few months. Although many of the initial concerns about SANE programs have not been realized and there have been important public health gains to those who continue to attend them, SANE programs deserve more careful, unbiased, longitudinal

  17. Thermoelectric needle probe for temperature measurements in biological materials.

    Science.gov (United States)

    Korn, U; Rav-Noy, Z; Shtrikman, S; Zafrir, M

    1980-04-01

    In certain biological and medical applications it is important to measure and follow temperature changes inside a body or tissue. Any probe inserted into a tissue causes damage to tissue and distortion to the initial temperature distribution. To minimize this interference, a fine probe is needed. Thus, thin film technology is advantageous and was utilized by us to produce sensitive probes for these applications. The resulting probe is a small thermocouple at the tip of a thin needle (acupuncture stainless steel needle, approximately 0.26 mm in diameter and length in the range 5-10 cm was used). The junction was produced at the needle's tip by coating the needle with thin layers of insulating and thermoelectric materials. The first layer is an insulating one and is composed of polyacrylonitrile (PAN) and polymide produced by plasma polymerization and dip-coating respectively. This layer covers all the needle except the tip. The second layer is a vacuum deposited thermoelectric thin layer of Bi-5% Sb alloy coating also the tip. The third layer is for insulation and protection and is composed of PAN and polyimide. In this arrangement the junction is at the needle's tip, the needle is one conductor, the thermoelectric layer is the other and they are isolated by the plastic layer. The probe is handy and mechanically sturdy. The sensitivity is typically 77 microV/degrees C at room temperature and is constant to within 2% up to 90 degrees C. The response is fast (less than 1 sec) the noise is small, (less than 0.05 degrees C) and because of the small dimension, damage to tissue and disturbance to the measured temperature field are minimal. PMID:7382928

  18. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    International Nuclear Information System (INIS)

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two

  19. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    Science.gov (United States)

    Reinhardt, Brian; Tittmann, Bernhard; Rempe, Joy; Daw, Joshua; Kohse, Gordon; Carpenter, David; Ames, Michael; Ostrovsky, Yakov; Ramuhalli, Pradeep; Montgomery, Robert; Chien, Hualte; Wernsman, Bernard

    2015-03-01

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two

  20. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Brian; Tittmann, Bernhard [The Pennsylvania State University (United States); Rempe, Joy; Daw, Joshua [Idaho National Laboratory (United States); Kohse, Gordon; Carpenter, David; Ames, Michael; Ostrovsky, Yakov [Massachusetts Institute of Technology (United States); Ramuhalli, Pradeep; Montgomery, Robert [Pacific Northwest National Laboratory (United States); Chien, Hualte [Argonne National Laboratory (United States); Wernsman, Bernard [Bechtel Marine Propulsion Corp (United States)

    2015-03-31

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two

  1. General Situation on Clinical Application of Dragon-Tiger Fighting Needling Technique in the Recent Years

    Institute of Scientific and Technical Information of China (English)

    何龙; 袁宜勤; 钟耀东; 何贤发; 黄国琪

    2008-01-01

    @@ Depending upon the descriptions of the ancient literature, such as Jin Zhen Fu (Odes to Golden Needles, ), the dragon-tiger fighting needling technique has the effects to dredge the meridians, circulate qi, activate blood, stop and remove pain. "Dragon" implies to twist the needle leftward for reinforcing, and "tiger" means to twist the needle rightward for reducing. To twist the needle leftward and rightward alternately is termed "fighting". After the arrival of the needling sensation by inserting the needle to the proper depth, the needle is first twisted leftward with the thumb forward in a method of nine yang numbers, and then twisted backward and rightward with the thumb backward in a method of six yin numbers, in alternation of reinforcing and reducing repeatedly. Therefore, the general information on clinical application of dragon-tiger fighting needling technique in the recent sixteen years is given in the following.

  2. Does large needle aspiration biopsy add pain to the thyroid nodule evaluation?

    Science.gov (United States)

    Carpi, Angelo; Rossi, Giuseppe; Nicolini, Andrea; Iervasi, Giorgio; Russo, Matteo; Mechanick, Jeffrey

    2013-01-01

    Thyroid large needle aspiration biopsy is disregarded because it is thought to be associated with pain. This is in contrast with our 32 years long experience. We surveyed reports of pain in patients examined with fine needle aspiration biopsy (78, 87.2% women, mean age 59 years) or FNAB+large needle aspiration biopsy (48, 87.5% women, mean age 60 years). Each patient was questioned regarding a) no unpleasant sensation (score "0"); b) unpleasant sensation ("1"); c) mild pain (no analgesic used; "2"); or d) pain (analgesic used; "3"). The mean size of the needle used was for FNAB 22.3±0.7 or 20.8±1 gauge in the fine needle aspiration or fine needle aspiration plus large needle aspiration biopsy group, respectively (pfine needle aspiration plus large needle aspiration biopsy group. However, the pain score in the fine needle aspiration biopsy or fine needle aspiration biopsy plus large needle aspiration biopsy group was not significantly different. Large needle aspiration biopsy after fine needle aspiration biopsy does not add any discomfort or pain and therefore in light of the demonstrable benefits, should be included in clinical algorithms for the evaluation of thyroid nodules. PMID:23536779

  3. Does large needle aspiration biopsy add pain to the thyroid nodule evaluation?

    Directory of Open Access Journals (Sweden)

    Angelo Carpi

    Full Text Available Thyroid large needle aspiration biopsy is disregarded because it is thought to be associated with pain. This is in contrast with our 32 years long experience. We surveyed reports of pain in patients examined with fine needle aspiration biopsy (78, 87.2% women, mean age 59 years or FNAB+large needle aspiration biopsy (48, 87.5% women, mean age 60 years. Each patient was questioned regarding a no unpleasant sensation (score "0"; b unpleasant sensation ("1"; c mild pain (no analgesic used; "2"; or d pain (analgesic used; "3". The mean size of the needle used was for FNAB 22.3±0.7 or 20.8±1 gauge in the fine needle aspiration or fine needle aspiration plus large needle aspiration biopsy group, respectively (p<.0001. The number of percutaneous punctures was higher in the fine needle aspiration plus large needle aspiration biopsy group. However, the pain score in the fine needle aspiration biopsy or fine needle aspiration biopsy plus large needle aspiration biopsy group was not significantly different. Large needle aspiration biopsy after fine needle aspiration biopsy does not add any discomfort or pain and therefore in light of the demonstrable benefits, should be included in clinical algorithms for the evaluation of thyroid nodules.

  4. Effect and safety of deep needling and shallow needling for functional constipation: a multicenter, randomized controlled trial.

    Science.gov (United States)

    Wu, Jiani; Liu, Baoyan; Li, Ning; Sun, Jianhua; Wang, Lingling; Wang, Liping; Cai, Yuying; Ye, Yongming; Liu, Jun; Wang, Yang; Liu, Zhishun

    2014-12-01

    Aupuncture is widely used for functional constipation. Effect of acupuncture might be related to the depth of needling; however, the evidence is limited. This trial aimed to evaluate the effect and safety of deep needling and shallow needling for functional constipation, and to assess if the deep needling and shallow needling are superior to lactulose. We conducted a prospective, superiority-design, 5-center, 3-arm randomized controlled trial. A total of 475 patients with functional constipation were randomized to the deep needling group (237), shallow needling group (119), and lactulose-controlled group (119) in a ratio of 2:1:1. Sessions lasted 30 minutes each time and took place 5 times a week for 4 weeks in 2 acupuncture groups. Participants in the lactulose group took lactulose orally for 16 continuous weeks. The primary outcome was the change from baseline of mean weekly spontaneous bowel movements (SBMs) during week 1 to 4 (changes from the baselines of the weekly SBMs at week 8 and week 16 in follow-up period were also assessed simultaneously). Secondary outcomes were the weekly SBMs of each assessing week, the mean score change from the baseline of constipation-related symptoms over week 1 to 4, and the time to the first SBM. Emergency drug usage and adverse effects were monitored throughout the study.SBMs and constipation-related symptoms were all improved in the 3 groups compared with baseline at each time frame (P0.05, both compared with the lactulose group). The changes of mean weekly SBMs at week 8 and week 16 in the follow-up period were 2 (2), 2 (2.5) in the deep needling group, 2 (3), 1.5 (2.5) in the shallow needling group, and 1 (2), 1 (2) in the lactulose group (Pabdominal distention during spontaneous defecating, or Cleveland Clinic Scores over week 1 to 4. However, the lactulose group got better effect than other 2 acupuncture groups in improving stool consistency (Pacupuncture groups were both lower than in the lactulose group at each time

  5. Investigation of Microopto-eletromechanical Angular Velocity and Acceleration Transducers based on Optical Tunneling Effect

    Science.gov (United States)

    Busurin, V. I.; Lwin, Naing Htoo; Tuan, Pham Anh

    In this paper the possibility of microopto-electromechanical (MOEM) angular velocity and acceleration transducers based on optical tunneling effect (OTE) is considered. The generalized model of MOEM transducers with various types of sensing elements (SE) is developed, transfer functions are investigated, and the errors with various design parameters of transducers are estimated.

  6. Amplifier for optimal reflection Coefficient of ultrasound transducer : A study of op amp based circuits for ultrasound transducers, targeted for low reflection Coefficient, high gain, and low noise

    OpenAIRE

    Mainou Gomez, José Francisco

    2012-01-01

    Reverberation is defined as equally-spaced, bright linear echoes resulting from reflection from specular-type interfaces. They are provoked by the acoustic Impedance change between the tissue and transducer front surface. B. Angelsen developed a mathematical approach to correct this ultrasound artifact by coupling the ultrasound transducer with an ideal electrical load in order to obtain zero reflection coefficients on the transducer from face [1]. However, when analyzing Impedance spectrosco...

  7. The Current State of Silicone-Based Dielectric Elastomer Transducers.

    Science.gov (United States)

    Madsen, Frederikke B; Daugaard, Anders E; Hvilsted, Søren; Skov, Anne L

    2016-03-01

    Silicone elastomers are promising materials for dielectric elastomer transducers (DETs) due to their superior properties such as high efficiency, reliability and fast response times. DETs consist of thin elastomer films sandwiched between compliant electrodes, and they constitute an interesting class of transducer due to their inherent lightweight and potentially large strains. For the field to progress towards industrial implementation, a leap in material development is required, specifically targeting longer lifetime and higher energy densities to provide more efficient transduction at lower driving voltages. In this review, the current state of silicone elastomers for DETs is summarised and critically discussed, including commercial elastomers, composites, polymer blends, grafted elastomers and complex network structures. For future developments in the field it is essential that all aspects of the elastomer are taken into account, namely dielectric losses, lifetime and the very often ignored polymer network integrity and stability. PMID:26773231

  8. Determination of Precise Instantaneous Height at Multibeam Transducer

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jianhu; ZHANG Hongmei; John E. Hughes Clarke

    2007-01-01

    To overcome the shortcomings of the traditional multibeam survey and data processing, a new method is presented for the precise determination of the instantaneous height at the multibeam transducer by the blend of GPS height and heave signals. Before signal blend, GPS height and heave signals need to be corrected first to the transducer center by attitude correction. Second, the GPS height needs to be checked and modified by heave check and modification itself. Butterworth and FFT (fast Fourier transformation) were used in the signal blend. Finally, FFT is thought to be appropriate in signal processing. The new method efficiently overcomes the shortcomings of the traditional method, and this is proven well by the MBS (multibeam bathymetric system) experiment.

  9. A vibration energy harvester using magnet/piezoelectric composite transducer

    Science.gov (United States)

    Qiu, Jing; Chen, Hengjia; Wen, Yumei; Li, Ping; Yang, Jin; Li, Wenli

    2014-05-01

    In this research, a vibration energy harvester employing the magnet/piezoelectric composite transducer to convert mechanical vibration energy into electrical energy is presented. The electric output performance of a vibration energy harvester has been investigated. Compared to traditional magnetoelectric transducer, the proposed vibration energy harvester has some remarkable characteristic which do not need binder. The experimental results show that the presented vibration energy harvester can obtain an average power of 0.39 mW for an acceleration of 0.6g at frequency of 38 Hz. Remarkably, this power is a very encouraging power figure that gives the prospect of being able to power a widely range of wireless sensors in wireless sensor network.

  10. Force transducers based on the stress dependence of coercive force

    Science.gov (United States)

    Garshelis, I. J.

    1993-05-01

    An alternative measurement regime for magnetoelastic force transducers, based on variations in coercive field, is described. Hc is shown to be more directly related to the primary magnetic influence of stress, namely, the orientation of effective anisotropy, than conventionally used magnetization related parameters. The stress dependence of Hc is shown to generally reflect opposing factors associated with rotational and wall displacement magnetization reversal processes. In materials wherein Hc≪K/Ms wall motion dominates and if the product of λs/K and yield stress is high enough, large monotonic reductions of Hc with positive (tensile) stress are shown to be possible. A more complex variation of Hc with increasing compression is similarly expected. Experimental results from a transducer having an 18% Ni maraging steel core support these expectations.

  11. Broadband electrostatic acoustic transducer for ultrasonic measurements in liquids.

    Science.gov (United States)

    Cantrell, J H; Heyman, J S; Yost, W T; Torbett, M A; Breazeale, M A

    1979-01-01

    A broadband capacitive electrostatic acoustic transducer (ESAT) has been developed for use in a liquid environment at megahertz frequencies. The ESAT basically consists of a thin conductive membrane stretched over a metallic housing. The membrane functions as the ground plate of a parallel plate capacitor, the other plate being a dc biased electrode recessed approximately 10 mum from the electrically grounded membrane. An ultrasonic wave incident on the membrane varies the membrane-electrode gap spacing and generates an electrical signal proportional to the wave amplitude. The entire assembly is sealed for immersion in a liquid environment. Calibration of the ESAT with incident ultrasonic waves of constant displacement amplitude from 1 to 15 MHz reveals a decrease in signal response with increasing frequency independent of membrane tension. The use of the ESAT as a broadband ultrasonic transducer in liquids with a predictable frequency response is promising.

  12. The Current State of Silicone-Based Dielectric Elastomer Transducers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Daugaard, Anders Egede; Hvilsted, Søren;

    2016-01-01

    Silicone elastomers are promising materials for dielectric elastomer transducers (DETs) due to their superior properties such as high efficiency, reliability and fast response times. DETs consist of thin elastomer films sandwiched between compliant electrodes, and they consti- tute an interesting...... class of transducer due to their inherent lightweight and potentially large strains. For the field to progress towards industrial implementation, a leap in material devel- opment is required, specifically targeting longer lifetime and higher energy densities to provide more efficient transduction at lower...... of the elastomer are taken into account, namely dielectric losses, life- time and the very often ignored polymer network integrity and stability....

  13. Development of pressure transducer re-instrumentating technique (II)

    International Nuclear Information System (INIS)

    Development of FP gas pressure transducer re-instrumentating technique have been conducted since 1985. The initial stage, the followings have been made : design and fabrication of re-instrumentation device and in pile performance test ; development of remote welding and fabrication technique of re-instrumentating device to irradiated fuel rod in the hot cell ; and remote inserting technique of fuel rod into capsule. In 1990, a power ramping test was carried out instrumentating two irradiated fuel rod with re-instrumentated devices respectively. As a result of performance test, it was fond that FP gas pressure transducer had been successively indicating the inner pressure corresponding to linear heat rate of fuels. At present, the power ramping test adopting these techniques acquired is on-going in JMTR (Japan Materials Testing Reactor). (author)

  14. Comprehensive helicopter rotor instrumentation - A retrofit approach using miniature transducers

    Science.gov (United States)

    Jacklin, Stephen A.; Mort, Ray; Morrison, Dwayne

    1992-01-01

    This paper reports an approach used to retrofit a set of full-scale main rotor blades with 290 miniature pressure transducers, 46 strain gages, and 24 miniature accelerometers. Normally, in order to avoid disturbing the aerodynamics of the rotor flow field, the pressure instrumentation must be integrally built into the body of the rotor blades. However, using a method developed with NASA, miniature pressure transducers are mounted to the blade exterior surface without degrading the quality of the blade aerodynamics. Moreover, it is estimated that this approach reduced costs by more than 50 percent over building a set of pressure instrumented blades. The aerodynamic measurement objectives are presented as are instrumentation design considerations, type of instrumentation used, assembly process, and the installed instrumentation characteristics.

  15. Electrocaloric Response of Ferroelectric Material Applicable as Electrothermal Transducer

    Directory of Open Access Journals (Sweden)

    Saber Mohammadi

    2013-01-01

    Full Text Available Electrocaloric response of the PMN-10PT is measured experimentally and compared with the numerical results. Based on the compatibility of the experimental and numerical results, feasibility of using ferroelectric materials as an electrothermal transducer has been investigated. In this study, electrocaloric response of three different ferroelectric capacitors (PMN-10PT, PMN-25PT, and PZN-4.5PT under an applied periodic electric field have been investigated. Alternative switching of the electrocaloric elements with specific boundary conditions generates a directed heat flux. It can be concluded that each ferroelectric material can be used as a transducer in a special temperature range that in which it has good electrocaloric response.

  16. Fiber optic ultrasound transducers with carbon/PDMS composite coatings

    Science.gov (United States)

    Mosse, Charles A.; Colchester, Richard J.; Bhachu, Davinder S.; Zhang, Edward Z.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

    2014-03-01

    Novel ultrasound transducers were created with a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS) that was dip coated onto the end faces of optical fibers. The CNTs were functionalized with oleylamine to allow for their dissolution in xylene, a solvent of PDMS. Ultrasound pulses were generated by illuminating the composite coating with pulsed laser light. At distances of 2 to 16 mm from the end faces, ultrasound pressures ranged from 0.81 to 0.07 MPa and from 0.27 to 0.03 MPa with 105 and 200 μm core fibers, respectively. Using an optical fiber hydrophone positioned adjacent to the coated 200 µm core optical fiber, ultrasound reflectance measurements were obtained from the outer surface of a sheep heart ventricle. The results of this study suggest that ultrasound transducers that comprise optical fibers with CNT-PDMS composite coatings may be suitable for miniature medical imaging probes.

  17. Optimization of large-scale fabrication of dielectric elastomer transducers

    DEFF Research Database (Denmark)

    Hassouneh, Suzan Sager

    Polypower A/S employs a large-scale process for manufacturing DE films with one-sided corrugated surfaces. The DEs are manufactured by coating an elastomer mixture to a corrugated carrier web, thereby imprinting the corrugations onto the elastomer. The corrugated elastomer is then sputtered with metal...... electrodes on the corrugated surface, and due to these corrugated surfaces the metal electrodes maintain conductivities up to more than 100% strain of the elastomer film. The films are then laminated in multiple layers to fabricate DE transducers. However, the current manufacturing process is not trouble......-free, and two issues in particular have great influence on the performance of DE transducers. The first issue is the release of the corrugated elastomer film from the carrier web, due to the large surface area and flexible nature of the elastomer film, while the second issue relates to the lamination of DE...

  18. Simulating arbitrary-geometry ultrasound transducers using triangles

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1996-01-01

    -echo field. The spatial impulse response has only been determined analytically for a few geometries and using apodization over the transducer surface generally makes it impossible to find the response analytically. A popular approach to find the general field is thus to split the aperture into small...... number of transducers can be defined and their properties manipulated. The program can calculate all types of ultrasound fields, and can also be used for simulating B-mode and color flow images. Both the focusing and apodization can be set to be dynamic with respect to time, and it is thus possible to......-field response of a rectangle, as the triangle equations are far more complicated. This approach is therefore best suited for accurate modeling of fields, whereas the rectangle program is better suited to make fast simulated images, since contributions from many scatterers are summed here and the error is...

  19. Numerical description of discharge characteristics of the plasma needle

    International Nuclear Information System (INIS)

    The plasma needle is a small atmospheric, nonthermal, radio-frequency discharge, generated at the tip of a needle, which can be used for localized disinfection of biological tissues. Although several experiments have characterized various qualities of the plasma needle, discharge characteristics and electrical properties are still not well known. In order to provide initial estimates on electrical properties and quantities such as particle densities, we employed a two-dimensional, time-dependent fluid model to describe the plasma needle. In this model the balance equation is solved in the drift-diffusion approach for various species and the electron energy, as well as Poisson's equation. We found that the plasma production occurs in the sheath region and results in a steady flux of reactive species outwards. Even at small (2 to the He background, N2+ is the dominant ion. The electron density is typically 1011 cm-3 and the dissipated power is in the order of 10 mW. These results are consistent with the experimental data available and can give direction to the practical development of the plasma needle

  20. [Needle tract seeding of hepatocellular carcinoma after liver transplantation].

    Science.gov (United States)

    Mrzljak, Anna; Kardum-Skelin, Ika; Blasković, Darko; Skegro, Dinko; Jadrijević, Stipislav; Colić-Cvrlje, Vesna

    2011-09-01

    Ultrasound guided fine needle aspiration cytology (FNAC) and core needle biopsy (CNB) are effective methods for the diagnosis of focal hepatic lesions. In case of neoplastic lesions, however, this may be followed by the seeding of malignant cells along the needle tract. We report a case of subcutaneous needle tract seeding of hepatocellular carcinoma (HCC) 25 months after liver transplantation. A 57-year-old man with compensated hepatitis-B-related liver cirrhosis was diagnosed with HCC by CNB, and the lesion was resected. Ten months after the procedure, FNAC of a small hepatic lesion confirmed tumor recurrence. The patient was successfully transplanted and 25 months later, a subcutaneous tumor appeared on the abdominal wall over the previous site of puncture without further dissemination of the disease. Total resection of the lesion confirmed HCC. It remains undetermined whether the seeding appeared after FNAC or CNB. After 18-month follow-up the patient was uneventful. The objectives of this report are to present clinical aspects and outcome of HCC needle tract seeding in a transplanted patient, discussing the problems and pitfalls of diagnostic workup and management of HCC. PMID:23126051

  1. Biopsy Needle Localization and Tracking Using ROI-RK Method

    Directory of Open Access Journals (Sweden)

    Yue Zhao

    2014-01-01

    Full Text Available ROI-RK method is a biopsy needle localization and tracking method. Previous research work has proved that it has a robust performance on different series of simulated 3D US volumes. Unfortunately, in real situations, because of the strong speckle noise of the ultrasound image and the different echogenic properties of the tissues, the real 3D US volumes have more complex background than the simulated images used previously. In this paper, to adapt the ROI-RK method in real 3D US volumes, a line-filter enhancement calculation only in the ROI is added to increase the contrast between the needle and background tissue, decreasing the phenomenon of expansion of the biopsy needle due to reverberation of ultrasound in the needle. To make the ROI-RK method more stable, a self-correction system is also implemented. Real data have been acquired on an ex vivo heart of lamb. The result of the ROI-RK method shows that it is capable to localize and track the biopsy needle in real situations, and it satisfies the demand of real-time application.

  2. Needle localization of small pediatric tumors for surgical biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Hardaway, B.W.; Hoffer, F.A. [Dept. of Diagnostic Imaging, St. Jude Children' s Research Hospital, Memphis, TN (United States); Rao, B.N. [Dept. of Surgery, St. Jude Children' s Research Hospital, Memphis Tennessee (United States)

    2000-05-01

    Background. Small pediatric tumors may be difficult to biopsy or resect. Objective. To examine the benefits of needle localization of a variety of small pediatric tumors before surgical biopsy or excision. Materials and methods. Seven patients aged 1-19 years underwent 12 procedures for needle localization of suspected tumor. Two patients had undergone previous biopsies without needle localization with negative results. Computed tomography (four patients) or ultrasonography (three patients) guided needle placement. Each patient had suspected tumor(s) in 1-3 anatomical sites, including thigh (7), lung (2), parasacral region (2), and iliac bone (1). Results. All 12 lesions (9 less than 1 cm{sup 3} in volume) were successfully localized for excision or biopsy. Three small (<1 cm{sup 3}) soft-tissue lesions (two ganglioneuroblastomas and one ganglioneuroma) were excised from one patient, a 0.65-cm{sup 3} residual soft-tissue sarcoma from another; and recurrent bilateral teratomas from a third. Two peripheral primitive neuroectodermal tumors were excised with positive margins from a fourth patient. Two lesions contained only fibrosis, as determined by histopathology. Two other patients underwent thoracoscopic removal of lung metastases that were less than 0.1 cm{sup 3}. Conclusion. Needle localization allows effective and less invasive excision or biopsy of a variety of small pediatric soft-tissue lesions. (orig.)

  3. Laryngeal chondrosarcoma diagnosed by core-needle biopsy.

    Science.gov (United States)

    Miyamaru, Satoru; Haba, Koichi

    2014-01-01

    We report a case of chondrosarcoma of the larynx, diagnosed by a percutaneous core-needle biopsy (CNB). Cartilaginous tumors of the larynx are usually diagnosed by biopsy with direct laryngomicroscopy under general anesthesia. However, patients find it difficult to undergo a biopsy under general anesthesia, for physical, economic, and social reasons. Instead, we can readily detect and sample tumors of the larynx using ultrasound under local anesthesia with reduced stress. Concerning needle-puncture biopsies, including fine-needle aspiration cytology (FNAC) and CNB, some studies have reported needle track dissemination, a possible complication in patients with malignant tumors. Thus, in the head and neck region, we generally use FNAC for biopsies, not CNB. However, it can be difficult to diagnose bone tumors by cytology alone. Regarding primary bone tumors, only one study has reported needle track dissemination by CNB, in osteosarcoma of the femur. Additionally, this complication has not been reported before with chondrosarcoma anywhere in the body. To our knowledge, this is the first report concerning chondrosarcoma of the larynx diagnosed by percutaneous CNB. We recommend CNB as a useful and safe diagnostic technique for primary bone tumors in the head and neck region.

  4. Evaluation of large-needle biopsy for the diagnosis of cancer.

    Science.gov (United States)

    Roussel, F; Nouvet, G

    1995-01-01

    The arguments for a choice between a large or fine needle in the diagnosis of tumors are still unclear. This paper reviews the advantages and disadvantages of large-needle biopsy and fine needle aspiration. Reports indicate that although the procedures have the same diagnostic efficacy, the risk of tumor seeding is far higher following large-needle biopsy. For this reason it should be avoided for the diagnosis of cancer. The risk of tumor seeding after fine needle aspiration may be reduced by performance through a cover of normal parenchyma, by maintaining suction during withdrawal of the needle and by examining samples for quality during the procedure. PMID:7762331

  5. Local Area Damage Detection in Composite Structures Using Piezoelectric Transducers

    OpenAIRE

    Lichtenwalner, Peter F.; Sofge, Donald A.

    2007-01-01

    An integrated and automated smart structures approach for structural health monitoring is presented, utilizing an array of piezoelectric transducers attached to or embedded within the structure for both actuation and sensing. The system actively interrogates the structure via broadband excitation of multiple actuators across a desired frequency range. The structure's vibration signature is then characterized by computing the transfer functions between each actuator/sensor pair, and compared t...

  6. Characterization of HIFU transducers designed for sonochemistry application: Acoustic streaming.

    Science.gov (United States)

    Hallez, L; Touyeras, F; Hihn, J-Y; Bailly, Y

    2016-03-01

    Cavitation distribution in a High Intensity Focused Ultrasound sonoreactors (HIFU) has been extensively described in the recent literature, including quantification by an optical method (Sonochemiluminescence SCL). The present paper provides complementary measurements through the study of acoustic streaming generated by the same kind of HIFU transducers. To this end, results of mass transfer measurements (electrodiffusional method) were compared to optical method ones (Particle Image Velocimetry). This last one was used in various configurations: with or without an electrode in the acoustic field in order to have the same perturbation of the wave propagation. Results show that the maximum velocity is not located at the focal but shifted near the transducer, and that this shift is greater for high powers. The two cavitation modes (stationary and moving bubbles) are greatly affect the hydrodynamic behavior of our sonoreactors: acoustic streaming and the fluid generated by bubble motion. The results obtained by electrochemical measurements show the same low hydrodynamic activity in the transducer vicinity, the same shift of the active focal toward the transducer, and the same absence of activity in the post-focal axial zone. The comparison with theoretical Eckart's velocities (acoustic streaming in non-cavitating media) confirms a very high activity at the "sonochemical focal", accounted for by wave distortion, which induced greater absorption coefficients. Moreover, the equivalent liquid velocities are one order of magnitude larger than the ones measured by PIV, confirming the enhancement of mass transfer by bubbles oscillation and collapse close to the surface, rather than from a pure streaming effect. PMID:26585023

  7. Development of an omnidirectional SH0 piezoceramic transducer

    Science.gov (United States)

    Belanger, Pierre; Boivin, Guillaume

    2016-02-01

    Ultrasonic guided waves are now routinely used in non-destructive evaluation. In plate-like structures, three fundamental modes can propagate, namely A0, S0 and SH0. Most of the guided wave literature has thus far focused on the use of A0 and/or S0 because these modes are easy to generate in plate-like structures using standard piezoceramic transducers. Yet, at low frequency, A0 and S0 are dispersive. The consequence of dispersion is that signal processing becomes complex for long propagation distances. SH0, on the other hand, has the particularity of being the only non-dispersive guided wave mode. Omnidirectional transduction of SH0 requires a rotational surface stress which cannot be easily generated using standard piezoceramic transducers. This project investigated the use of piezoceramic shear plates cut into six trapezoids bonded to a plate in order to form a discretized circle. The individual elements of the hexagonal shaped transducer were synchronized to generate shear surface stress simultaneously. The external diameter of the discretized circle was chosen to be half the SH0 wavelength at the desired centre frequency. Finite element simulations using the Comsol Multiphysics environment showed that in a 1.6 mm aluminium plate the modal selectivity of the transducer was more than 30 dB at 100 kHz. The concept was then validated experimentally on a 1.6 mm aluminium plate. The 3D experimental displacement field was measured using a laser Doppler vibrometer system. The experimental modal selectivity was 20 dB.

  8. Digital objects as "transducers" in scientific web publishing

    OpenAIRE

    Koltzenburg, Claudia

    2007-01-01

    Scientific web publishing offers an attractive bundle of phenomena for feminist technoscientific investigation. This article focuses on research articles in scientific journals and aims at identifying a range of exclusionary practices in the current publishing system, which need to be critically addressed. For this purpose, the functionalities of digital objects are studied using the analogy of a piezoelectric crystal as a transducer in obstetric ultrasonography (Karen Barad 2001). This is em...

  9. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Brian [Pennsylvania State Univ., University Park, PA (United States). Dept. of Engineering Science and Mechanics; Tittmann, Bernhard [Pennsylvania State Univ., University Park, PA (United States). Dept. of Engineering Science and Mechanics; Rempe, Joy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Daw, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kohse, Gordon [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States). MIT Nuclear Reactor Lab.; Carpenter, David [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States). MIT Nuclear Reactor Lab.; Ames, Micheal [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States). MIT Nuclear Reactor Lab.; Ostrovsky, Yakov [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States). MIT Nuclear Reactor Lab.; Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chien, Hualte [Argonne National Lab. (ANL), Argonne, IL (United States); Wernsman, Bernard [Bettis Atomic Power Lab. (BAPL), West Mifflin, PA (United States). Bechtel Marine Propulsion Corp.

    2014-07-01

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) provide harsh environments in and near the core that can severely test material performance and limit their operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration radiation performance of fuels and materials. In To reduce the amount of Material and Test Reactor (MTR) irradiations required, DOE is also funding development of enhanced instrumentation that will be able to obtain data, with unprecedented accuracy and resolution, that are required to validate new multi-scale multiphysics modeling tools . It is not feasible to obtain such data with the current state of instrumentation technology. To address this need, PSU and collaborators have started an experiment to test the potential for utilizing ultrasonic instruments in-pile. Ultrasonic sensors must be resistant to high neutron flux, high gamma radiation, and high temperature. PSU and collaborators have designed, fabricated, and started to irradiate piezoelectric and magnetostrictive transducers designed to perform in such harsh environments. Three piezoelectric transducers were fabricated with aluminum nitride, zinc oxide, and bismuth titanate as the active element. The transducers are coupled kovar and aluminum waveguides of which pulse-echo ultrasonic measurements are made in-situ. Two magnetostrictive transducers were fabricated with Remendur and Arnokrome as the active elements. These devices will be pulsed and monitored in-situ. (1) Selection of candidate sensor materials as well as optimization of test assembly parameters (2) High temperature benchmark testing and (3) initial data from the irradiation will be reported.

  10. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    International Nuclear Information System (INIS)

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) provide harsh environments in and near the core that can severely test material performance and limit their operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration radiation performance of fuels and materials. In To reduce the amount of Material and Test Reactor (MTR) irradiations required, DOE is also funding development of enhanced instrumentation that will be able to obtain data, with unprecedented accuracy and resolution, that are required to validate new multi-scale multiphysics modeling tools . It is not feasible to obtain such data with the current state of instrumentation technology. To address this need, PSU and collaborators have started an experiment to test the potential for utilizing ultrasonic instruments in-pile. Ultrasonic sensors must be resistant to high neutron flux, high gamma radiation, and high temperature. PSU and collaborators have designed, fabricated, and started to irradiate piezoelectric and magnetostrictive transducers designed to perform in such harsh environments. Three piezoelectric transducers were fabricated with aluminum nitride, zinc oxide, and bismuth titanate as the active element. The transducers are coupled kovar and aluminum waveguides of which pulse-echo ultrasonic measurements are made in-situ. Two magnetostrictive transducers were fabricated with Remendur and Arnokrome as the active elements. These devices will be pulsed and monitored in-situ. (1) Selection of candidate sensor materials as well as optimization of test assembly parameters (2) High temperature benchmark testing and (3) initial data from the irradiation will be reported.

  11. Differential scanning calorimetry of superelastic Nitinol for tunable cymbal transducers

    OpenAIRE

    Feeney, Andrew; Lucas, Margaret

    2015-01-01

    Recent research has shown that estimations of the transformation temperatures of superelastic Nitinol using differential scanning calorimetry can be inaccurate, in part, due to the residual stress in the material. Superelastic Nitinol is selected as the end-cap material in a tunable cymbal transducer. The differential scanning calorimetry accuracy is initially probed by comparing transformation temperature measurements of cold-worked superelastic Nitinol with the same material after an anneal...

  12. Engine Oil Condition Monitoring Using High Temperature Integrated Ultrasonic Transducers

    OpenAIRE

    Jeff Bird; Cheng-Kuei Jen; Zhigang Sun; Pierre Sammut; Brian Galeote; Makiko Kobayashi; Kuo-Ting Wu; Nezih Mrad

    2011-01-01

    The present work contains two parts. In the first part, high temperature integrated ultrasonic transducers (IUTs) made of thick piezoelectric composite films, were coated directly onto lubricant oil supply and sump lines of a modified CF700 turbojet engine. These piezoelectric films were fabricated using a sol-gel spray technology. By operating these IUTs in transmission mode, the amplitude and velocity of transmitted ultrasonic waves across the flow channel of the lubricant oil in supply and...

  13. Forward and Backward Application of Symbolic Tree Transducers

    OpenAIRE

    Fülöp, Zoltán; Vogler, Heiko

    2012-01-01

    We consider symbolic tree automata (sta) and symbolic tree transducers (stt). We characterize s-recognizable tree languages (which are the tree languages recognizable by sta) in terms of (classical) recognizable tree languages and relabelings. We prove that sta and the recently introduced variable tree automata are incomparable with respect to their recognition power. We define symbolic regular tree grammars and characterize s-regular tree languages in terms of regular tree languages and rela...

  14. Differential Pressure Transducer for Corrosion Monitoring of Iron

    OpenAIRE

    Amar Prasad Yadav

    2014-01-01

    In this study, differential pressure transducer (DPT) has been applied as an alternate corrosion monitoring device for monitoring corrosion of iron in atmospheric environment by measuring very small changes in the amount of oxygen. The result of corrosion current obtained from DPT method has been compared with that obtained from AC impedance method. The difference in the value of corrosion current obtained from these two methods was attributed to the error in choosing the value of proportiona...

  15. SU-D-210-07: The Dependence On Acoustic Velocity of Medium On the Needle Template and Electronic Grid Alignment in Ultrasound QA for Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, P; Kapoor, R; Curran, B [Virginia Commonwealth University, Richmond, VA (United States); HH McGuire VA Hospital, Richmond, VA (United States)

    2015-06-15

    Purpose: To analyze the impact on acoustic velocity (AV) of two different media (water and milk) using the needle template/electronic grid alignment test. Water, easily available, makes a good material to test the alignment of the template and grid although water’s AV (1498 m/s at 25°C) is significantly different from tissue (1540 m/s). Milk, with an AV much closer (1548 m/s) to prostate tissue, may be a good substitute for water in ultrasound quality assurance testing. Methods: Tests were performed using a Hitachi ultrasound unit with a mechanical arrangement designed to position needles parallel to the transducer. In this work, two materials – distilled water and homogenized whole milk (AVs of 1498 and 1548 m/s at 25°C) were used in a phantom to test ultrasound needle/grid alignment. The images were obtained with both materials and analyzed for their placement accuracy. Results: The needle template/electronic grid alignment tests showed displacement errors between measured and calculated values. The measurements showed displacements of 2.3mm (water) and 0.4mm (milk), and 1.6mm (water) and 0.3mm (milk) at depths of 7cm and 5cm respectively from true needle positions. The calculated results showed a displacement of 2.36 mm (water); 0.435mm (milk), and 1.66mm (water) and 0.31mm (milk) at a depth of 7cm and 5cm respectively. The displacements in the X and Y directions were also calculated. At depths of 7cm and 5cm, the (ΔX,ΔY) displacements in water were (0.829mm, 2.21mm) and (0.273mm, 1.634mm) and for milk were (0.15mm, 0.44mm) and (0.05mm, 0.302mm) respectively. Conclusion: The measured and calculated values were in good agreement for all tests. They show that milk provides superior results when performing needle template and electronic grid alignment tests for ultrasound units used in prostate brachytherapy.

  16. SU-D-210-07: The Dependence On Acoustic Velocity of Medium On the Needle Template and Electronic Grid Alignment in Ultrasound QA for Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To analyze the impact on acoustic velocity (AV) of two different media (water and milk) using the needle template/electronic grid alignment test. Water, easily available, makes a good material to test the alignment of the template and grid although water’s AV (1498 m/s at 25°C) is significantly different from tissue (1540 m/s). Milk, with an AV much closer (1548 m/s) to prostate tissue, may be a good substitute for water in ultrasound quality assurance testing. Methods: Tests were performed using a Hitachi ultrasound unit with a mechanical arrangement designed to position needles parallel to the transducer. In this work, two materials – distilled water and homogenized whole milk (AVs of 1498 and 1548 m/s at 25°C) were used in a phantom to test ultrasound needle/grid alignment. The images were obtained with both materials and analyzed for their placement accuracy. Results: The needle template/electronic grid alignment tests showed displacement errors between measured and calculated values. The measurements showed displacements of 2.3mm (water) and 0.4mm (milk), and 1.6mm (water) and 0.3mm (milk) at depths of 7cm and 5cm respectively from true needle positions. The calculated results showed a displacement of 2.36 mm (water); 0.435mm (milk), and 1.66mm (water) and 0.31mm (milk) at a depth of 7cm and 5cm respectively. The displacements in the X and Y directions were also calculated. At depths of 7cm and 5cm, the (ΔX,ΔY) displacements in water were (0.829mm, 2.21mm) and (0.273mm, 1.634mm) and for milk were (0.15mm, 0.44mm) and (0.05mm, 0.302mm) respectively. Conclusion: The measured and calculated values were in good agreement for all tests. They show that milk provides superior results when performing needle template and electronic grid alignment tests for ultrasound units used in prostate brachytherapy

  17. Ultrasonic Heat Transfer Enhancement Using a Horn-Type Transducer

    Science.gov (United States)

    Nomura, Shinfuku; Yamamoto, Akira; Murakami, Koichi

    2002-05-01

    The purpose of this study is to clarify experimentally the influence of streaming induced by ultrasonic vibration on heat transfer using a horn-type ultrasonic vibrator. A horn tip of 6 mm diameter and 60.7 kHz resonant frequency was used as the ultrasonic transducer. Heat transfer experiments for a downward-facing horizontal heating surface with ultrasonic vibration from below were carried out in a natural convection region. The acoustic jet in the water from the horn tip of the transducer regarded as a nozzle exit was induced by this transducer, and as a result, up to a ten-fold increase in heat transfer coefficient was obtained by application of 20 W in both tap water and degassed water. It was found that the mechanism of heat transfer enhancement by ultrasonic vibration in tap water can be classified into four categories. In degassed water, heat transfer enhancement is influenced not by the acoustic jet, but by small-scale perturbations by cavitation microjets.

  18. MEMS ultrasonic transducer for monitoring of steel structures

    Science.gov (United States)

    Jain, Akash; Greve, David W.; Oppenheim, Irving J.

    2002-06-01

    Ultrasonic methods can be used to monitor crack propagation, weld failure, or section loss at critical locations in steel structures. However, ultrasonic inspection requires a skilled technician, and most commonly the signal obtained at any inspection is not preserved for later use. A preferred technology would use a MEMS device permanently installed at a critical location, polled remotely, and capable of on-chip signal processing using a signal history. We review questions related to wave geometry, signal levels, flaw localization, and electromechanical design issues for microscale transducers, and then describe the design, characterization, and initial testing of a MEMS transducer to function as a detector array. The device is approximately 1-cm square and was fabricated by the MUMPS process. The chip has 23 sensor elements to function in a phased array geometry, each element containing 180 hexagonal polysilicon diaphragms with a typical leg length of 49 microns and an unloaded natural frequency near 3.5 MHz. We first report characterization studies including capacitance-voltage measurements and admittance measurements, and then report initial experiments using a conventional piezoelectric transducer for excitation, with successful detection of signals in an on-axis transmission experiment and successful source localization from phased array performance in an off-axis transmission experiment.

  19. An Analysis of Transducer Mass Loading Effect Inshaker Testing

    Directory of Open Access Journals (Sweden)

    A. D. Karle

    2014-06-01

    Full Text Available Modal Analysis has been a developing science in the experimental evaluation of the dynamic properties of the structures. Frequency Response Function (FRF is one of the major steps in modal analysis. Measured frequency response functions (FRFs are used to extract modal parameters. It is also known that the accuracy and the reliability of various analyses using the measured FRFs depend strongly on the quality of measured data. It is well known that the quality of measured frequency response functions (FRFs is adversely affected by many factors, most significant sources being noise and systematic errors like mass loading effects of transducers. A transducer mounted on a vibrating system changes the dynamics of the structure due to the addition of extra mass and introduces errors into measured FRFs. One problem with this is the production of unrealistic results, which cause the measured resonant frequencies to be less than the correct values. These errors also lead to incorrect prediction of modal parameters. In many situations, the mass loading effect is ignored in the analytical and experimental process, based on a usual assumption that the transducer mass is negligible compared to that of the structure under test. However, when light-weighted structures are investigated, this effect can be significant.

  20. Efficient Driving of Piezoelectric Transducers Using a Biaxial Driving Technique.

    Directory of Open Access Journals (Sweden)

    Samuel Pichardo

    Full Text Available Efficient driving of piezoelectric materials is desirable when operating transducers for biomedical applications such as high intensity focused ultrasound (HIFU or ultrasound imaging. More efficient operation reduces the electric power required to produce the desired bioeffect or contrast. Our preliminary work [Cole et al. Journal of Physics: Condensed Matter. 2014;26(13:135901.] suggested that driving transducers by applying orthogonal electric fields can significantly reduce the coercivity that opposes ferroelectric switching. We present here the experimental validation of this biaxial driving technique using piezoelectric ceramics typically used in HIFU. A set of narrow-band transducers was fabricated with two sets of electrodes placed in an orthogonal configuration (following the propagation and the lateral mode. The geometry of the ceramic was chosen to have a resonance frequency similar for the propagation and the lateral mode. The average (± s.d. resonance frequency of the samples was 465.1 (± 1.5 kHz. Experiments were conducted in which each pair of electrodes was driven independently and measurements of effective acoustic power were obtained using the radiation force method. The efficiency (acoustic/electric power of the biaxial driving method was compared to the results obtained when driving the ceramic using electrodes placed only in the pole direction. Our results indicate that the biaxial method increases efficiency from 50% to 125% relative to the using a single electric field.

  1. Deconvolution based photoacoustic reconstruction for directional transducer with sparsity regularization

    Science.gov (United States)

    Moradi, Hamid; Tang, Shuo; Salcudean, Septimiu E.

    2016-03-01

    We define a deconvolution based photoacoustic reconstruction with sparsity regularization (DPARS) algorithm for image restoration from projections. The proposed method is capable of visualizing tissue in the presence of constraints such as the specific directivity of sensors and limited-view Photoacoustic Tomography (PAT). The directivity effect means that our algorithm treats the optically-generated ultrasonic waves based on which direction they arrive at the transducer. Most PA image reconstruction methods assume that sensors have omni-directional response; however, in practice, the sensors show higher sensitivity to the ultrasonic waves coming from one specific direction. In DPARS, the sensitivity of the transducer to incoming waves from different directions are considered. Thus, the DPARS algorithm takes into account the relative location of the absorbers with respect to the transducers, and generates a linear system of equations to solve for the distribution of absorbers. The numerical conditioning and computing times are improved by the use of a sparse Discrete Fourier Transform (DCT) representation of the distribution of absorption coefficients. Our simulation results show that DPARS outperforms the conventional Delay-and-Sum reconstruction method in terms of CNR and RMS errors. Experimental results confirm that DPARS provides images with higher resolution than DAS.

  2. Dual-Frequency Piezoelectric Transducers for Contrast Enhanced Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    K. Heath Martin

    2014-11-01

    Full Text Available For many years, ultrasound has provided clinicians with an affordable and effective imaging tool for applications ranging from cardiology to obstetrics. Development of microbubble contrast agents over the past several decades has enabled ultrasound to distinguish between blood flow and surrounding tissue. Current clinical practices using microbubble contrast agents rely heavily on user training to evaluate degree of localized perfusion. Advances in separating the signals produced from contrast agents versus surrounding tissue backscatter provide unique opportunities for specialized sensors designed to image microbubbles with higher signal to noise and resolution than previously possible. In this review article, we describe the background principles and recent developments of ultrasound transducer technology for receiving signals produced by contrast agents while rejecting signals arising from soft tissue. This approach relies on transmitting at a low-frequency and receiving microbubble harmonic signals at frequencies many times higher than the transmitted frequency. Design and fabrication of dual-frequency transducers and the extension of recent developments in transducer technology for dual-frequency harmonic imaging are discussed.

  3. Focused intravascular ultrasonic probe using dimpled transducer elements.

    Science.gov (United States)

    Chen, Y; Qiu, W B; Lam, K H; Liu, B Q; Jiang, X P; Zheng, H R; Luo, H S; Chan, H L W; Dai, J Y

    2015-02-01

    High-frequency focused intravascular ultrasonic probes were fabricated in this study using dimple technique based on PMN-PT single crystal and lead-free KNN-KBT-Mn ceramic. The center frequency, bandwidth, and insertion loss of the PMN-PT transducer were 34 MHz, 75%, and 22.9 dB, respectively. For the lead-free probe, the center frequency, bandwidth, and insertion loss were found to be 40 MHz, 72%, and 28.8 dB, respectively. The ultrasonic images of wire phantom and vessels with good resolution were obtained to evaluate the transducer performance. The -6 dB axial and lateral resolutions of the PMN-PT probe were determined to be 58 μm and 131 μm, respectively. For the lead-free probe, the axial and lateral resolutions were found to be 44 μm and 125 μm, respectively. These results suggest that the mechanical dimpling technique has good potential in preparing focused transducers for intravascular ultrasound applications. PMID:25108608

  4. Analyzing a Vibrating Wire Transducer using Coupled Resonator Circuits

    Directory of Open Access Journals (Sweden)

    POP, S.

    2015-08-01

    Full Text Available This paper intends to be an approach on the vibrating wire transducer from the perspective of the necessary rules used for a correct measurement procedure. There are several studies which analyze the vibrating wire transducer as a mechanical system. However, a comparative time-domain analysis between the mechanical and the electrical model is lacking. The transducer analysis is based on a theoretical analysis of the equivalent circuit, on both excitation and response time intervals. The electrical model consists of two magnetic coupled resonating circuits. When connected to an excitation source, there will be an energy transfer from the coil to the wire. The maximum energy transfer will occur at the vibrating wire's frequency of resonance. Using the transient regime analysis, it has been proven that, in the response time interval - when the wire vibrates freely, the current through the circuit that models the wire describes the oscillating movement of the wire. A complex signal is obtained, that contains both coil's and wire's frequencies of resonance, strongly dependent with theirs parasitic elements. The mathematical analysis highlights the similarity between mechanical and electrical model and the procedures in order to determine the wire frequency of resonance from the output signal.

  5. Development of ultrasonic testing equipment incorporating electromagnetic acoustic transducer

    International Nuclear Information System (INIS)

    This paper describes an automatic flaw detection equipment and heat-resistant ultrasonic transducer for plate thickness measurement. The automatic flaw detection equipment is used during in-service inspection. It comprises an angle-beam electromagnetic acoustic transducer (EMAT), mounted on a vehicle, for scanning the pipe surface to be inspected. The EMAT functions without direct contact with the pipe surface through a coupling liquid, the vehicle does not require a guide track installed on the pipe surface, since it is equipped with magnetic wheels that adhere to the pipe, permitting it to travel along the circumferential weld joint of a carbon steel pipe. Another heat-resistant ultrasonic transducer is a normal beam EMAT and is used during plant operation. As a result, the automatic flaw detection equipment could detect a 1 mm deep notch cut on a test piece of 25 mm thick carbon steel plate. The vehicle location accuracy on the piping was ±2 mm. The normal beam EMAT could measure the plate thickness, within ±0.3 mm accuracy for the range of plate thickness 4 mm to 12 mm at 300degC. (author)

  6. Precision of Needle Tip Localization Using a Receiver in the Needle

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav Ivanov; Jensen, Jørgen Arendt

    2008-01-01

    often motion is introduced to the discomfort of the patient. Vilkomerson and co-workers suggested in 1981 the placement of an ultrasound receiver close to the needle tip. The received echoes are detected by add-on hardware. The maximum echo is assumed to originate from a beam directly above the detector...... and investigates their precision. The first method uses conventional imaging. Instead of detecting the maximum echo, as previously suggested, the center of mass is found both across beams and along the received signals, thus decreasing the sensitivity to noise. The second method is based synthetic aperture (SA......) scanning. The position of the tip is found via triangulation which involves solving a system of linear equations. The robustness to noise is ensured through averaging a number of estimates. The sensor is a ring of piezo-electric film making it possible to receive waves from any direction. The results were...

  7. Flexible PVDE comb transducers for excitation of axisymmetric guided waves in pipe

    International Nuclear Information System (INIS)

    Flexible PVDF pipe comb transducers are easy to install by wrapping around any size pipe. It is possible to mechanically couple these transducers to the pipe thereby eliminating the need to bond electrodes to the film and couple the transducer to the pipe. The simple fabrication process, installation, and affordability of these transducers makes them realistic candidates for condition based monitoring of some critical pipeline applications. These transducers are capable of exciting lower order axisymmetric modes with minimal radial displacement and maximum axial displacement as well as modes with both surface displacement components. This versatility is extremely important since under certain loading conditions modes with significant radial displacement are almost completely attenuated.

  8. Tunable-angle wedge transducer for improved acoustophoretic control in a microfluidic chip

    DEFF Research Database (Denmark)

    Iranmanesh, I.; Barnkob, Rune; Bruus, Henrik;

    2013-01-01

    coupling angle, and transducer actuation method (single-frequency actuation or frequency-modulation actuation). The energy-density analysis is based on measuring the transmitted light intensity through a microfluidic channel filled with a suspension of 5 µm diameter beads and the results with the tunable...... uniform particle patterns with average acoustic energy densities comparable to those obtained using single-frequency actuation.......We present a tunable-angle wedge ultrasound transducer for improved control of microparticle acoustophoresis in a microfluidic chip. The transducer is investigated by analyzing the pattern of aligned particles and induced acoustic energy density while varying the transducer geometry, transducer...

  9. A Comparative Study on Fine Needle Aspiration Cytology versus Fine Needle Capillary Cytology in Thyroid Nodules

    Science.gov (United States)

    Tauro, Leo F.; Lobo, Geover J.; Fernandes, Hilda; George, Celine; Aithala, P. Sathyamoorthy; Shenoy, Divakar; Shetty, Prathvi

    2012-01-01

    Objectives Fine needle aspiration cytology (FNAC/FNA) is the primary investigation for thyroid nodules. Fine needle capillary cytology (FNCC/FNC) is an alternative technique not commonly used, though it is easy to perform. Both the techniques have their own advantages and disadvantages. This study aims to compare these two cytological techniques for better specimen and cytological diagnosis. Methods This prospective study was conducted on 50 patients attending the FR Muller Medical College Hospital from May 2006 to April 2008. The patients with thyroid nodules (diagnosed by palpation) were subjected to both the cytological techniques; FNA and FNC. The specimen and results were compared and then correlated with the final histopathological findings wherever surgical specimens were available (38 cases). Results The mean age of the patients was 39.16 with a female predominance. The majority of cases were diagnosed to have nodular goiters. The FNC technique yielded 88% diagnostic superiority and adequate specimens compared to 94% by FNA. Sensitivity was 50% for FNC and 100% for FNA while specificity was 100% for both techniques; accuracy score was 97.4% for FNC and 100% for FNA in predicting malignancy. While sensitivity was 75% for FNC and 100% for FNA; specificity was 100% for both techniques, and accuracy score was 97.4% for FNC and 100% for FNA in the prediction of neoplasia. Conclusion The results indicated that there was no significant difference between the two techniques; if done in tandem can give better and accurate cytological diagnosis. In highly cellular lesions, in which abundant material was obtained, FNC was more likely to be diagnostically superior, but FNA can diagnose most of the lesions. In less cellular lesions, FNA is more likely to be diagnostically superior to FNC. PMID:22496942

  10. Carbon Nanotubes Based Glucose Needle-type Biosensor

    Directory of Open Access Journals (Sweden)

    Hong Li

    2008-03-01

    Full Text Available A novel needle-type biosensor based on carbon nanotubes is reported. Thebiosensor was prepared by packing a mixture of multi-wall carbon nanotubes (MWCNTs,graphite powder and glucose oxidase (Gox freeze-dried powder into a glass capillary of 0.5mm inner diameter. The resulting amperometric biosensor was characterizedelectrochemically using amperometry in the presence of hydrogen peroxide and in thepresence of glucose. The glucose biosensor sensitivity was influenced by the glucoseoxidase concentration within the MWCNTs mixture. The optimized glucose needle-typebiosensor displayed better sensitivity and stability, and a detected range of up to 20 mM.Based on its favorable stability, the needle biosensor was first time used in real-timemonitoring system as a kind of online glucose detector. The decay of current response isless than 10% after 24-hour continuous observation.

  11. Superficial treatment of mammalian cells using plasma needle

    Energy Technology Data Exchange (ETDEWEB)

    Stoffels, E; Kieft, I E; Sladek, R E J [Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2003-12-07

    Interactions of a small-size, non-thermal plasma (plasma needle) with living cells in culture are studied. We have demonstrated the non-destructive character of the plasma needle: under moderate conditions (low-power and low concentration of molecular species) the plasma needle does not heat biological samples and does not induce cell death. Treatment of living cells is restricted to the cell exterior (membrane). As a result of the interactions of plasma radicals with cell adhesion molecules, cell attachment is temporarily interrupted; the loose cells can be removed, reattached or transferred. This effect may prove very useful in fine surgery, where a part of the tissue must be removed with high-precision, without damage to the adjacent cells and without inflammatory reaction.

  12. Understanding the physiology of postharvest needle abscission in balsam fir

    Directory of Open Access Journals (Sweden)

    Mason Thane Macdonald

    2015-11-01

    Full Text Available Balsam fir (Abies balsamea trees are commonly used as a specialty horticultural species for Christmas trees and associated greenery in eastern Canada and United States. Postharvest needle abscission has always been a problem, but is becoming an even bigger challenge in recent years presumably due to increased autumn temperatures and earlier harvesting practices. An increased understanding of postharvest abscission physiology in balsam fir may benefit the Christmas tree industry while simultaneously advancing our knowledge in senescence and abscission of conifers in general. Our paper describes the dynamics of needle abscission in balsam fir while identifying key factors that modify abscission patterns. Concepts such as genotypic abscission resistance, nutrition, environmental factors, and postharvest changes in water conductance and hormone evolution are discussed as they relate to our understanding of the balsam fir abscission physiology. Our paper ultimately proposes a pathway for needle abscission via ethylene and also suggests other potential alternative pathways based on our current understanding.

  13. Chondromalacia Patellae Treated by Warming Needle and Rehabilitation Training

    Institute of Scientific and Technical Information of China (English)

    QIU Ling; ZHANG Min; ZHANG Ji; GAO Le-nv; CHEN Da-wei; LIU Jun; SHE Jia-yi; WANG Ling; YU Jin-yan; HUANG Le-ping; BAI Yang

    2009-01-01

    Objective:To observe the effect of wanning needle combined with rehabilitation training on chondromalacia patellae in a randomized controlled trial. Methods: The 92 cases were randomly divided into a treatment group treated by warming needle plus rehabilitation training (47 cases) and a control group treated by medication plus rehabilitation training (45 cases), and the therapeutic effect was compared after 20 sessions.Results: The pain was relieved more obviously in the treatment group than in the control group (P<0.05),and the total effective rate was 91.8% and 71.1% respectively (P<0.01). Conclusion: Warming needle plus rehabilitation training was superior in the therapeutic effect and duration of producing relief of pain to medication plus rehabilitation training in treating chondromalacia patellae.

  14. Surgical Removal of an Unrecognized Tapestry Needle from the Urethra.

    Science.gov (United States)

    Temiz, Mustafa Zafer; Yuruk, Emrah; Teberik, Kutlu; Kandirali, Engin

    2015-04-24

    The variety of intraurethral foreign bodies has been reported in literature. Most of them tend to be self-inserted because of sexual or erotic reasons. We report a 23-year old male patient who had tapestry needle into his urethra, which was not self-inserted. The patient was referred to our institution with dysuria and hematuria. There was microscopic hematuria in urine analysis and no pathologic sign in sonography. The needle was detected in proximal urethra in pelvic X-ray and endoscopic visualization revealed that it was trapped in mucosa. The needle was successfully removed by open surgery. Main treatment for the removal of urethral foreign bodies is usually endoscopic but open surgery may be required in some cases especially cutting foreign bodies. PMID:26236453

  15. Flat HIFU transducer with a sawtooth-shaped ultrasound radiation face

    Science.gov (United States)

    Son, Keon-Ho; Cho, Young-Ki; Kim, Dae-Seung; Kim, Myung-Deok; Kang, Kook-Jin

    2013-10-01

    High-intensity focused ultrasound (HIFU) transducers are spherically-curved in order to obtain a high intensity gain of the converged ultrasound energy at the geometrical focus. Ultrasound imaging devices monitor the procedure of HIFU treatment in ultrasound-guided HIFU systems where the image probe is positioned at the apex of the HIFU transducer, which has a spherical surface. However, the remote image probe's location yields a poor image quality compared to that obtained using conventional ultrasound imaging where the image probe is in direct contact with the surface. A phased array HIFU transducer with a new structure is suggested to overcome this limitation. The centers of the array elements are distributed over the flat surface of the transducer. However, the elements are tilted to form a geometrical focus, like a transducer with a spherically-curved surface, to obtain a high focal gain. The cross-section of the ultrasound radiation face of the transducer resembles the teeth of a saw. The acoustic field emitted from this transducer was simulated in order to design and produce the transducer. The simulation was compared with the measured sound field to verify that the transducer was correctly manufactured and designed; subsequently, the acoustic power was measured, and ultrasound images were obtained through the installation of an image probe on the transducer, which confirmed the application of this transducer to HIFU treatment.

  16. Analytical modeling and experimental validation of a V-shape piezoelectric ultrasonic transducer

    Science.gov (United States)

    Li, Xiaoniu; Yao, Zhiyuan

    2016-07-01

    In this paper, an analytical model of a V-shape piezoelectric ultrasonic transducer is presented. The V-shape piezoelectric ultrasonic transducer has been widely applied to the piezoelectric actuator (ultrasonic motor), ultrasonic aided fabrication, sensor, and energy harvesting device. The V-shape piezoelectric ultrasonic transducer consists of two Langevin-type transducers connected together through a coupling point with a certain coupling angle. Considering the longitudinal and lateral movements of a single beam, the symmetrical and asymmetrical modals of the V-shape piezoelectric ultrasonic transducer are calculated. By using Hamilton–Lagrange equations, the electromechanical coupling model of the V-shape piezoelectric ultrasonic transducer is proposed. The influence of the coupling angle and cross-section on modal characteristics and electromechanical coupling coefficient are analyzed by the analytical model. A prototype of the V-shape piezoelectric ultrasonic transducer is fabricated, and the results of the experiments are in good agreement with the analytical model.

  17. Immediate effect of Fu's subcutaneous needling for low back pain

    Institute of Scientific and Technical Information of China (English)

    FU Zhong-hua; CHEN Xin-yuan; LU Li-juan; LIN Jian; XU Jian-guo

    2006-01-01

    @@ The traditional Chinese acupuncture has been reported to alleviate pain and is widely accepted as a complement therapy for pain relief in the world.1In 1996, a novel acupuncture strategy, Fu's subcutaneous needling (FSN), was developed from the traditional Chinese acupuncture, but quite different from it.2 In FSN, needles are penetrated and swayed in the subcutaneous layer, but not the muscular layer. The choosing of its insertion points doesn't obey the principles of traditional Chinese medicine. To date, FSN has been widely used by clinicians in China for its good job in pain management though the systemic and rigorous studies are still lack.

  18. EUS-Guided Needle-Based Confocal Laser Endomicroscopy

    DEFF Research Database (Denmark)

    Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra;

    2015-01-01

    the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure...... that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve...

  19. Endobronchial ultrasound-guided transbronchial needle aspiration of lesions in mediastinum

    DEFF Research Database (Denmark)

    Eckardt, Jens

    2010-01-01

    BACKGROUND: Lesions in mediastinum can represent malignancy and warrants further workup. Commonly a diagnosis is achieved by conventional bronchoscopy, transbronchial needle aspiration or CT guided fine needle aspiration, however a number of patients remain undiagnosed despite these common...

  20. Needles and Other Sharps (Safe Disposal Outside of Health Care Settings)

    Science.gov (United States)

    ... arthritis, cancer, diabetes, hepatitis, HIV/AIDS, infertility, migraines, multiple sclerosis, osteoporosis, blood clotting disorders, and psoriasis. Examples of sharps include: Needles – hollow needles used to inject drugs (medication) under the skin Syringes – devices used to inject ...

  1. Core needle biopsy versus fine needle aspiration biopsy in breast--a historical perspective and opportunities in the modern era.

    Science.gov (United States)

    Nassar, Aziza

    2011-05-01

    Breast fine-needle aspiration biopsy (FNAB) by palpation is on the decline, due to its limitations in diagnostic accuracy, decreased sensitivity, and its replacement with core needle biopsy (CNB). Despite its decreasing utility, superficial fine-needle aspiration (FNA) in breast is still the main modality for evaluating metastatic lesions, recurrence, and axillary lymph node metastasis. New modalities including proteomic pattern expression and methylation profiling of breast lesions are other promising techniques that can be used as ancillary tests for refining the diagnosis of breast lesions using FNAB. Image-guided breast FNA proves to be a successful alternative with high sensitivity and specificity. In this review, the advantages, disadvantages, and inherent limitations of breast FNA and CNB, and new advanced techniques are discussed. PMID:20949457

  2. CLINICAL OBSERVATION ON TREATMENT OF 120CASES OF PERIPHERY FACIAL PARALYSIS WITH PENETRATION NEEDLING

    Institute of Scientific and Technical Information of China (English)

    王芳妮

    2000-01-01

    In the present study,the therapeutic effect of penetration needling was observed in 120cases facial paralysis patients and compared with that of the routine needling in another105cases.Re-sults showed that though no significant difference was found between these two groups in the therapeu-tic effect,the acupoints used were fewer in penetration needling group and its effect on tear and poste-rior-auricular pain was superior to that of routine needling.

  3. Effects of insertion speed and trocar stiffness on the accuracy of needle position for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J. [Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, State College, Pennsylvania 16802 (United States); Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 and Mechanical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2012-04-15

    Purpose: In prostate brachytherapy, accurate positioning of the needle tip to place radioactive seeds at its target site is critical for successful radiation treatment. During the procedure, needle deflection leads to seed misplacement and suboptimal radiation dose to cancerous cells. In practice, radiation oncologists commonly use high-speed hand needle insertion to minimize displacement of the prostate as well as the needle deflection. Effects of speed during needle insertion and stiffness of trocar (a solid rod inside the hollow cannula) on needle deflection are studied. Methods: Needle insertion experiments into phantom were performed using a 2{sup 2} factorial design (2 parameters at 2 levels), with each condition having replicates. Analysis of the deflection data included calculating the average, standard deviation, and analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: The stiffer tungsten carbide trocar is effective in reducing the average and standard deviation of needle deflection. The fast insertion speed together with the stiffer trocar generated the smallest average and standard deviation for needle deflection for almost all cases. Conclusions: The combination of stiff tungsten carbide trocar and fast needle insertion speed are important to decreasing needle deflection. The knowledge gained from this study can be used to improve the accuracy of needle insertion during brachytherapy procedures.

  4. Real-time three-dimensional flexible needle tracking using two-dimensional ultrasound

    NARCIS (Netherlands)

    Vrooijink, G.J.; Abayazid, M.; Misra, S.

    2013-01-01

    Needle insertion is one of the most commonly performed minimally invasive procedures. Visualization of the needle during insertion is key for either successful diagnosis or therapy. This work presents the real-time three-dimensional tracking of flexible needles during insertion into a soft-tissue si

  5. Mechanics-Based Model for Predicting In-Plane Needle Deflection with Multiple Bends

    NARCIS (Netherlands)

    Roesthuis, R.J.; Abayazid, M.; Misra, S.

    2012-01-01

    Bevel-tipped flexible needles naturally bend when inserted into soft tissue. Steering such needles along curved paths allows one to avoid anatomical obstacles and reach locations inside the human body which are unreachable with rigid needles. In this study, a mechanics-based model is presented which

  6. An Air-Coupled Multiple Moving Membrane Micromachined Ultrasonic Transducer With Inverse Biasing Functionality.

    Science.gov (United States)

    Emadi, Arezoo; Buchanan, Douglas A

    2016-08-01

    A novel air-coupled multiple moving membrane-capacitive micromachined ultrasonic transducer ( [Formula: see text]-CMUT) with individually biased deflectable plates has been developed. Unlike the conventional capacitive micromachined ultrasonic transducer, this device cell structure includes an additional deflectable plate that is suspended underneath the transducer top plate. This added flexible plate contributes to the device signal transmission and reception. It is demonstrated that due to the presence of this added moving plate, the transducer is capable of operating under inverse bias condition, where the driving voltage is sandwiched between two grounded electrodes. COMSOL electromechanical simulations were conducted to investigate the influence of the transducer additional moving plate. A set of three individuals and an array of [Formula: see text]-CMUT transducers were fabricated using a sacrificial technique and with resonant frequencies ranging from 0.8 to 2.1 MHz. Electrical, optical, and pitch-catch acoustic measurements were performed to characterize the transducers properties under inverse bias condition. The experimental results are shown to be in good agreement with the simulation results for all of the fabricated transducers. It is shown that these transducers are fully functional under both normal and inverse bias conditions without any degradation in the transducer performance. PMID:27254861

  7. Electromechanical coupling factor of capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Caronti, Alessandro; Carotenuto, Riccardo; Pappalardo, Massimo

    2003-01-01

    Recently, a linear, analytical distributed model for capacitive micromachined ultrasonic transducers (CMUTs) was presented, and an electromechanical equivalent circuit based on the theory reported was used to describe the behavior of the transducer [IEEE Trans. Ultrason. Ferroelectr. Freq. Control 49, 159-168 (2002)]. The distributed model is applied here to calculate the dynamic coupling factor kw of a lossless CMUT, based on a definition that involves the energies stored in a dynamic vibration cycle, and the results are compared with those obtained with a lumped model. A strong discrepancy is found between the two models as the bias voltage increases. The lumped model predicts an increasing dynamic k factor up to unity, whereas the distributed model predicts a more realistic saturation of this parameter to values substantially lower. It is demonstrated that the maximum value of kw, corresponding to an operating point close to the diaphragm collapse, is 0.4 for a CMUT single cell with a circular membrane diaphragm and no parasitic capacitance (0.36 for a cell with a circular plate diaphragm). This means that the dynamic coupling factor of a CMUT is comparable to that of a piezoceramic plate oscillating in the thickness mode. Parasitic capacitance decreases the value of kw, because it does not contribute to the energy conversion. The effective coupling factor keff is also investigated, showing that this parameter coincides with kw within the lumped model approximation, but a quite different result is obtained if a computation is made with the more accurate distributed model. As a consequence, keff, which can be measured from the transducer electrical impedance, does not give a reliable value of the actual dynamic coupling factor.

  8. A Integrated Circuit for a Biomedical Capacitive Pressure Transducer

    Science.gov (United States)

    Smith, Michael John Sebastian

    Medical research has an urgent need for a small, accurate, stable, low-power, biocompatible and inexpensive pressure sensor with a zero to full-scale range of 0-300 mmHg. An integrated circuit (IC) for use with a capacitive pressure transducer was designed, built and tested. The random pressure measurement error due to resolution and non-linearity is (+OR-)0.4 mmHg (at mid-range with a full -scale of 300 mmHg). The long-term systematic error due to falling battery voltage is (+OR-)0.6 mmHg. These figures were calculated from measurements of temperature, supply dependence and non-linearity on completed integrated circuits. The sensor IC allows measurement of temperature to (+OR-)0.1(DEGREES)C to allow for temperature compensation of the transducer. Novel micropower circuit design of the system components enabled these levels of accuracy to be reached. Capacitance is measured by a new ratiometric scheme employing an on -chip reference capacitor. This method greatly reduces the effects of voltage supply, temperature and manufacturing variations on the sensor circuit performance. The limits on performance of the bandgap reference circuit fabricated with a standard bipolar process using ion-implanted resistors were determined. Measurements confirm the limits of temperature stability as approximately (+OR-)300 ppm/(DEGREES)C. An exact analytical expression for the period of the Schmitt trigger oscillator, accounting for non-constant capacitor charging current, was formulated. Experiments to test agreement with theory showed that prediction of the oscillator period was very accurate. The interaction of fundamental and practical limits on the scaling of the transducer size was investigated including a correction to previous theoretical analysis of jitter in an RC oscillator. An areal reduction of 4 times should be achievable.

  9. Vibration control via stiffness switching of magnetostrictive transducers

    Science.gov (United States)

    Scheidler, Justin J.; Asnani, Vivake M.; Dapino, Marcelo J.

    2016-04-01

    In this paper, a computational study is presented of structural vibration control that is realized by switching a magneto-strictive transducer between high and low stiffness states. Switching is accomplished by either changing the applied magnetic field with a voltage excitation or changing the shunt impedance on the transducer's coil (i.e., the magneto-strictive material's magnetic boundary condition). Switched-stiffness vibration control is simulated using a lumped mass supported by a damper and the magneto-strictive transducer (mount), which is represented by a nonlinear, electromechanical model. Free vibration of the mass is calculated while varying the mount's stiffness according to a reference switched-stiffness vibration control law. The results reveal that switching the magnetic field produces the desired change in stiffness, but also an undesired actuation force that can significantly degrade the vibration control. Hence, a modified switched-stiffness control law that accounts for the actuation force is proposed and implemented for voltage-controlled stiffness switching. The influence of the magneto-mechanical bias condition is also discussed. Voltage-controlled stiffness switching is found to introduce damping equivalent to a viscous damping factor up to about 0.13; this is shown to primarily result from active vibration reduction caused by the actuation force. The merit of magneto-strictive switched-stiffness vibration control is then quantified by comparing the results of voltage- and shunt-controlled stiffness switching to the performance of optimal magneto-strictive shunt damping. For the cases considered, optimal resistive shunt damping performed considerably better than both voltage- and shunt-controlled stiffness switching.

  10. Hot pressed piezo-electric ceramic elements for ultrasonic transducers

    International Nuclear Information System (INIS)

    Piezoelectric ceramics (PZT4, PZT5, PZT7 and SPN) were investigated for development of high frequency (30-100 MHz) normal and focussed transducers. Hot pressed piezoelectric materials with a controlled grain size of ∼ 2 μm and approaching theoretical density can be lapped down to 30 μm thickness without structural damage whereas conventional sintered piezoelectric material with gram sizes ranging from 2-15 μm and at least 3% porosity can only be lapped down to 100 μm. Hot pressed piezoelectric ceramics when compared with conventional piezoelectric ceramics, show higher values of coupling coefficient (10-20%), elastic compliance ∼ 12% and moderate increases in mechanical quality factor (Qm) and dielectric constant. The compressional sound velocity measured along the poling direction is very sensitive to the switching of dipoles other than 180o ones. The velocity increases as the polarization increases and this constitutes a useful method for quality control of the piezoelectric ceramic as it gives the correct thickness resonant frequency. By accurately measuring the change by a comparison method, the dipole behaviour can be better understood and the degree of polarization and depolarization can be established. Temperature dependent polarization and depolarization is also discussed in the light of dipole switching. Hot pressed SPN and PZT5 are sufficiently transparent to be considered for use in opto-ultrasonic applications such as in medicine. Because of the high value of the thickness-frequency constant and low Qm, SPN seems a better choice as a high frequency transducer material. The signal spectra of a high frequency transducer constructed from these materials is presented

  11. Structural peculiarities of single crystal diamond needles of nanometer thickness

    Science.gov (United States)

    Orekhov, Andrey S.; Tuyakova, Feruza T.; Obraztsova, Ekaterina A.; Loginov, Artem B.; Chuvilin, Andrey L.; Obraztsov, Alexander N.

    2016-11-01

    Diamond is attractive for various applications due to its unique mechanical and optical properties. In particular, single crystal diamond needles with high aspect ratios and sharp apexes of nanometer size are demanded for different types of optical sensors including optically sensing tip probes for scanning microscopy. This paper reports on electron microscopy and Raman spectroscopy characterization of the diamond needles having geometrically perfect pyramidal shapes with rectangular atomically flat bases with (001) crystallography orientation, 2–200 nm sharp apexes, and with lengths from about 10–160 μm. The needles were produced by selective oxidation of (001) textured polycrystalline diamond films grown by chemical vapor deposition. Here we study the types and distribution of defects inside and on the surface of the single crystal diamond needles. We show that sp3 type point defects are incorporated into the volume of the diamond crystal during growth, while the surface of the lateral facets is enriched by multiple extended defects. Nitrogen addition to the reaction mixture results in increase of the growth rate on {001} facets correlated with the rise in the concentration of sp3 type defects.

  12. Randomized interventions for needle procedures in children with cancer.

    Science.gov (United States)

    Hedén, L; VON Essen, L; Ljungman, G

    2009-07-01

    The aim of this study was to examine whether children experience less fear, distress and pain connected to a routine needle insertion in an intravenous port when subjected to an intervention: blowing soap bubbles or having a heated pillow vs. standard care. Twenty-eight children, 2-7 years, cared for at a paediatric oncology unit, undergoing a routine needle insertion in an intravenous port were included consecutively. All children were subjected to two needle insertions; at the first they received standard care, and at the second standard care + a randomized intervention. Parents and nurses assessed children's fear, distress and pain on 0-100 mm visual analogue scales. According to parents' report, children experienced less fear when subjected to intervention vs. standard care reported by parents (P soap bubbles vs. standard care (n = 14), and less fear when subjected to standard care + heated pillow vs. standard care (P soap bubbles or having a heated pillow is more effective than standard care in reducing children's fear and distress in needle procedures, according to parents' report. PMID:19040458

  13. Percutaneous needle placement using laser guidance: a practical solution

    Science.gov (United States)

    Xu, Sheng; Kapoor, Ankur; Abi-Jaoudeh, Nadine; Imbesi, Kimberly; Hong, Cheng William; Mazilu, Dumitru; Sharma, Karun; Venkatesan, Aradhana M.; Levy, Elliot; Wood, Bradford J.

    2013-03-01

    In interventional radiology, various navigation technologies have emerged aiming to improve the accuracy of device deployment and potentially the clinical outcomes of minimally invasive procedures. While these technologies' performance has been explored extensively, their impact on daily clinical practice remains undetermined due to the additional cost and complexity, modification of standard devices (e.g. electromagnetic tracking), and different levels of experience among physicians. Taking these factors into consideration, a robotic laser guidance system for percutaneous needle placement is developed. The laser guidance system projects a laser guide line onto the skin entry point of the patient, helping the physician to align the needle with the planned path of the preoperative CT scan. To minimize changes to the standard workflow, the robot is integrated with the CT scanner via optical tracking. As a result, no registration between the robot and CT is needed. The robot can compensate for the motion of the equipment and keep the laser guide line aligned with the biopsy path in real-time. Phantom experiments showed that the guidance system can benefit physicians at different skill levels, while clinical studies showed improved accuracy over conventional freehand needle insertion. The technology is safe, easy to use, and does not involve additional disposable costs. It is our expectation that this technology can be accepted by interventional radiologists for CT guided needle placement procedures.

  14. Needle penetration of the globe during retrobulbar and peribulbar injections.

    Science.gov (United States)

    Hay, A; Flynn, H W; Hoffman, J I; Rivera, A H

    1991-07-01

    The charts of 23 patients with needle penetration of the globe during retrobulbar or peribulbar injections between January 1980 and May 1990 were reviewed. Possible needle penetration risk factors included high myopia, previous scleral buckling procedures, injection by nonophthalmologists, and poor patient cooperation during the injection. Of the 23 cases of ocular penetration, 16 (70%) were from sharp (22-, 23-, and 25-gauge) needles, and 7 (30%) were from blunt (23- and 25-gauge) needles. Management options depended on the severity of the intraocular injury. Retinal breaks without retinal detachment were treated by laser photocoagulation (four cases) or cryopexy (one case) and were observed in three cases. More advanced complications (retinal detachment and vitreous hemorrhage) were usually treated by pars plana vitrectomy with or without a scleral buckle (12 of 14 cases). The final visual acuity was 20/400 or better in only 2 of the 14 retinal detachment cases. In cases without retinal detachment, the final visual acuity was 20/50 or better in 7 of 9 cases. PMID:1891207

  15. Fine-needle aspiration biopsy. When is it most beneficial?

    Science.gov (United States)

    Peterson, I M; Brink, W J

    1990-09-01

    When fine-needle aspiration biopsy is done skillfully, it is an accurate, efficient, and cost-effective method for diagnosing many diseases in selected patients. This article describes its uses for palpable masses of the thyroid, breast, and peripheral lymph nodes and some nonpalpable lesions. The authors also discuss its advantages and disadvantages and technical considerations that affect accuracy. PMID:2399196

  16. The Single Needle Lockstitch Machine. [Sewing Seams.] Module 4.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on sewing seams, one in a series on the single needle lockstitch sewing machine for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

  17. The Single Needle Lockstitch Machine. [Constructing Darts.] Module 3.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on constructing darts, one in a series on the single needle lockstitch sewing machine for student self-study, contains two sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final…

  18. The Single Needle Lockstitch Machine. [Setting a Collar.] Module 5.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on sewing collars, one in a series on the single needle lockstitch sewing machine for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

  19. The Single Needle Lockstitch Machine. [Setting Zippers.] Module 8.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on setting zippers, one in a series on the single needle lockstitch sewing machine for student self-study, contains five sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

  20. Needle electromyographic findings in 98 patients with myositis.

    NARCIS (Netherlands)

    Blijham, P.J.; Hengstman, G.J.D.; Hama-Amin, A.D.; Engelen, B.G.M. van; Zwarts, M.J.

    2006-01-01

    BACKGROUND/AIMS: Little is known about the distribution of electromyographic (EMG) abnormalities in myositis even though this is relevant in daily practice. METHODS: A retrospective semiquantitative analysis of needle EMG findings was performed in a group of 98 patients with myositis. The frequency,

  1. Sensorimotor Learning of Acupuncture Needle Manipulation Using Visual Feedback.

    Directory of Open Access Journals (Sweden)

    Won-Mo Jung

    Full Text Available Humans can acquire a wide variety of motor skills using sensory feedback pertaining to discrepancies between intended and actual movements. Acupuncture needle manipulation involves sophisticated hand movements and represents a fundamental skill for acupuncturists. We investigated whether untrained students could improve their motor performance during acupuncture needle manipulation using visual feedback (VF.Twenty-one untrained medical students were included, randomly divided into concurrent (n = 10 and post-trial (n = 11 VF groups. Both groups were trained in simple lift/thrusting techniques during session 1, and in complicated lift/thrusting techniques in session 2 (eight training trials per session. We compared the motion patterns and error magnitudes of pre- and post-training tests.During motion pattern analysis, both the concurrent and post-trial VF groups exhibited greater improvements in motion patterns during the complicated lifting/thrusting session. In the magnitude error analysis, both groups also exhibited reduced error magnitudes during the simple lifting/thrusting session. For the training period, the concurrent VF group exhibited reduced error magnitudes across all training trials, whereas the post-trial VF group was characterized by greater error magnitudes during initial trials, which gradually reduced during later trials.Our findings suggest that novices can improve the sophisticated hand movements required for acupuncture needle manipulation using sensorimotor learning with VF. Use of two types of VF can be beneficial for untrained students in terms of learning how to manipulate acupuncture needles, using either automatic or cognitive processes.

  2. Removing Phosphorus from Aqueous Solutions Using Lanthanum Modified Pine Needles.

    Directory of Open Access Journals (Sweden)

    Xianze Wang

    Full Text Available The renewable pine needles was used as an adsorbent to remove phosphorus from aqueous solutions. Using batch experiments, pine needles pretreated with alkali-isopropanol (AI failed to effectively remove phosphorus, while pine needles modified with lanthanum hydroxide (LH showed relatively high removal efficiency. LH pine needles were effective at a wide pH ranges, with the highest removal efficiency reaching approximately 85% at a pH of 3. The removal efficiency was kept above 65% using 10 mg/L phosphorus solutions at desired pH values. There was no apparent significant competitive behavior between co-existing anions of sulfate, nitrate, and chloride (SO4(2-, NO3(- and Cl(-; however, CO3(2- exhibited increased interfering behavior as concentrations increased. An intraparticle diffusion model showed that the adsorption process occurred in three phases, suggesting that a boundary layer adsorption phenomena slightly affected the adsorption process, and that intraparticle diffusion was dominant. The adsorption process was thermodynamically unfavorable and non-spontaneous; temperature increases improved phosphorus removal. Total organic carbon (TOC assays indicated that chemical modification reduced the release of soluble organic compounds from 135.6 mg/L to 7.76 mg/L. This new information about adsorption performances provides valuable information, and can inform future technological applications designed to remove phosphorus from aqueous solutions.

  3. Removing Phosphorus from Aqueous Solutions Using Lanthanum Modified Pine Needles

    Science.gov (United States)

    Wang, Xianze; Liu, Zhongmou; Liu, Jiancong; Huo, Mingxin; Huo, Hongliang; Yang, Wu

    2015-01-01

    The renewable pine needles was used as an adsorbent to remove phosphorus from aqueous solutions. Using batch experiments, pine needles pretreated with alkali-isopropanol (AI) failed to effectively remove phosphorus, while pine needles modified with lanthanum hydroxide (LH) showed relatively high removal efficiency. LH pine needles were effective at a wide pH ranges, with the highest removal efficiency reaching approximately 85% at a pH of 3. The removal efficiency was kept above 65% using 10 mg/L phosphorus solutions at desired pH values. There was no apparent significant competitive behavior between co-existing anions of sulfate, nitrate, and chloride (SO42-, NO3- and Cl-); however, CO32- exhibited increased interfering behavior as concentrations increased. An intraparticle diffusion model showed that the adsorption process occurred in three phases, suggesting that a boundary layer adsorption phenomena slightly affected the adsorption process, and that intraparticle diffusion was dominant. The adsorption process was thermodynamically unfavorable and non-spontaneous; temperature increases improved phosphorus removal. Total organic carbon (TOC) assays indicated that chemical modification reduced the release of soluble organic compounds from 135.6 mg/L to 7.76 mg/L. This new information about adsorption performances provides valuable information, and can inform future technological applications designed to remove phosphorus from aqueous solutions. PMID:26630014

  4. Main flavonoids in needles of Larix decidu A

    NARCIS (Netherlands)

    Niemann, Gerard J.

    1975-01-01

    Present work. Freeze-dried needles were extracted with acetone-water. Ether and butanol fractions were separated by repeated banding on paper. Nine major flavonoids were isolated (in solution) and identified by chromatographic and UV spectral data of both the original and alkaline and/or acid hydrol

  5. Effects of percutaneous needle liver biopsy on dairy cow behaviour

    DEFF Research Database (Denmark)

    Mølgaard, Lene; Damgaard, Birthe Marie; Bjerre-Harpøth, Vibeke;

    2012-01-01

    behavioural changes for up to 19 h – and particularly for behaviour previously associated with pain. Even though the exact welfare impact of percutaneous needle liver biopsies in cows is not known, and the magnitude of the behavioural changes was limited, pain always has negative effects on animal welfare...

  6. Core needle biopsy guidance based on EMOCT imaging (Conference Presentation)

    Science.gov (United States)

    Iftimia, Nicusor V.; Park, Jesung; Maguluri, Gopi

    2016-03-01

    We present a novel method, based on encoder mapping OCT imaging, for real-time guidance of core biopsy procedures. This method provides real-time feedback to the interventional radiologist, such that he/she can reorient the needle during the biopsy and sample the most representative area of the suspicious mass that is being investigated. This aspect is very important for tailoring therapy to the specific cancer based on biomarker analysis, which will become one of the next big advances in our search for the optimal cancer therapy. To enable individualized treatment, the genetic constitution and the DNA repair status in the affected areas is needed for each patient. Thus, representative sampling of the tumor is needed for analyzing various biomarkers, which are used as a tool to personalize cancer therapy. The encoder-based OCT enables samping of large size masses and provides full control on the imaging probe, which is passed through the bore of the biopsy guidance needle. The OCT image is built gradually, based on the feedback of an optical encoder which senses the incremental movement of the needle with a few microns resolution. Tissue mapping is independent of the needle speed, while it is advanced through the tissue. The OCT frame is analyzed in real-time and tissue cellularity is reported in a very simple manner (pie chart). Our preliminary study on a rabbit model of cancer has demonstrated the capability of this technology for accurately differentiating between viable cancer and heterogeneous or necrotic tissue.

  7. Subcutaneous infusion: non-metal cannulae vs metal butterfly needles.

    Science.gov (United States)

    Torre, Maria Carrion

    2002-07-01

    This review aimed to evaluate the effectiveness of non-metal cannulae compared to metal butterfly needles in maintaining subcutaneous infusion sites in patients receiving palliative care. The Cochrane Library, Medline, Pre-Medline, Embase, CINAHL, Amed and Cancerlit were searched for relevant studies. Controlled trials comparing non-metal cannulae with metal butterfly needles for giving subcutaneous infusion to palliative care patients were included. The outcome considered was site duration in terms of hours of patency or until change was required. Four trials met the inclusion criteria although overall quality was poor due to low follow-up. Studies examined either Teflon or Vialon-coated catheters. All studies showed non-metal cannulae to be superior to metal. In individual studies estimates in mean increase in duration of the site range from 21 to 159 hours. It seems that non-metal cannulae are more effective in maintaining the duration of subcutaneous infusion sites than butterfly needles. Both types of non-metal catheter showed clear benefits. This review has not examined other outcomes but in general adverse effects lead to the removal of the catheter and so would be reflected in the outcome of considered. Although historically non-metal cannulae have been considerably more expensive there is now little difference between metal and Teflon-coated catheters. This review recommends the use of non-metal cannulae in preference to butterfly needles. PMID:12131852

  8. Superficial Needling Therapy for Tennis Elbow in 40 Cases

    Institute of Scientific and Technical Information of China (English)

    GE Heng-bi; XIAO Yuan-chun

    2003-01-01

    Superficial needling therapy was employed to treat 40 cases of tennis elbow. For the cases of qi and blood stagnation, cupping therapy was added. Thirty-eight cases were cured after one treatment and 2 cases were cured after two treatments.

  9. Failed needle decompression of bilateral spontaneous tension pneumothorax.

    Science.gov (United States)

    Bach, P T; Sølling, C

    2015-07-01

    This case report presents a young male admitted with primary bilateral spontaneous tension pneumothorax and severe respiratory distress. This is an extremely rare condition. The patient was on the verge of hypoxic cardiac arrest and the attempted needle thoracocentesis was unsuccessful. Needle thoracocentesis in the midclavicular line of the second intercostal space is widely used and recommended as first-line treatment of tension pneumothorax. Reviewing the literature, the procedure is not based on solid evidence. It has high failure rates and potentially serious complications. Alternatives to this approach are perhaps more appropriate. Correctly done, needle thoracocentesis has its place in the presence of a diagnosed or suspected tension pneumothorax when no other options are available. If needle thoracocentesis is chosen, then insertion in the mid-anterior axillary line of the 3rd-5th intercostal space is an appropriate alternative site. Otherwise, lateral thoracostomy, with or without chest tube insertion, is a safe procedure with a high success rate. It should be considered as the first-line treatment of tension pneumothorax, particularly in the unstable patient.

  10. Steering of flexible needles combining kinesthetic and vibratory force feedback

    NARCIS (Netherlands)

    Pacchierotti, Claudio; Abayazid, Momen; Misra, Sarthak; Prattichizzo, Domenico

    2014-01-01

    Needle insertion in soft-tissue is a minimally invasive surgical procedure which demands high accuracy. In this respect, robotic systems with autonomous control algorithms have been exploited as the main tool to achieve high accuracy and reliability. However, for reasons of safety and acceptance by

  11. COMMENTS ON CLINICAL APPLICATION OF LOCAL MULTI-NEEDLE PUNCTURING

    Institute of Scientific and Technical Information of China (English)

    MENG Xiangwen

    2002-01-01

    In the present paper, combining a few of typical cases, the author introduces his clinical experiences about the application of multiple acupuncture needles inserted into a certain local region for treatment of facial spasm,Iumbago, hyperplasis of the mammay glands and herpes zoster and gives some brief comments.

  12. Local Area Damage Detection in Composite Structures Using Piezoelectric Transducers

    CERN Document Server

    Lichtenwalner, Peter F

    1998-01-01

    An integrated and automated smart structures approach for structural health monitoring is presented, utilizing an array of piezoelectric transducers attached to or embedded within the structure for both actuation and sensing. The system actively interrogates the structure via broadband excitation of multiple actuators across a desired frequency range. The structure's vibration signature is then characterized by computing the transfer functions between each actuator/sensor pair, and compared to the baseline signature. Experimental results applying the system to local area damage detection in a MD Explorer rotorcraft composite flexbeam are presented.

  13. Quantum acousto-optic transducer for superconducting qubits

    CERN Document Server

    Shumeiko, V S

    2015-01-01

    We propose theory for reversible quantum transducer connecting superconducting qubits and optical photons using acoustic waves in piezoelectrics. The proposed device consists of integrated acousto-optic resonator that utilizes stimulated Brillouin scattering for phonon-photon conversion, and piezoelectric e?ect for coupling of phonons to qubits. We evaluate the phonon-photon coupling rate, and show that the required power of optical pump as well as the other device parameters providing full and faithful quantum conversion are feasible for implementation with the state of the art integrated acousto-optics.

  14. Speech recognition algorithms based on weighted finite-state transducers

    CERN Document Server

    Hori, Takaaki

    2013-01-01

    This book introduces the theory, algorithms, and implementation techniques for efficient decoding in speech recognition mainly focusing on the Weighted Finite-State Transducer (WFST) approach. The decoding process for speech recognition is viewed as a search problem whose goal is to find a sequence of words that best matches an input speech signal. Since this process becomes computationally more expensive as the system vocabulary size increases, research has long been devoted to reducing the computational cost. Recently, the WFST approach has become an important state-of-the-art speech recogni

  15. On the general governing equations of electromagnetic acoustic transducers

    CERN Document Server

    Saxena, Prashant

    2013-01-01

    In this paper, we present the general governing equations of electrodynamics and continuum mechanics that need to be considered while mathematically modelling the behaviour of electromagnetic acoustic transducers (EMATs). We consider the existence of finite deformations for soft materials and the possibility of electric currents, temperature gradients, and internal heat generation due to dissipation. Starting with Maxwell's equations of electromagnetism and balance laws of nonlinear elasticity, we present the governing equations and boundary conditions in incremental form in order to solve wave propagation problems of boundary value type.

  16. A distributed transducer system for functional electrical stimulation

    DEFF Research Database (Denmark)

    Gudnason, Gunnar; Nielsen, Jannik Hammel; Bruun, Erik;

    2001-01-01

    Implanted transducers for functional electrical stimulation (FES) powered by inductive links are subject to conflicting requirements arising from low link efficiency, a low power budget and the need for protection of the weak signals against strong RF electromagnetic fields. We propose a solution...... likely to be affected by the inductive link. Neural stimulators are affected to a lesser degree, but still benefit from the partitioning. As a test case, we have designed a transceiver and a sensor chip which implement this partitioning policy. The transceiver is designed to operate in the 6.78 MHz ISM...

  17. Development of a transducer for MiniGrail

    CERN Document Server

    Gottardi, L; Frossati, G

    2002-01-01

    We are developing a two-mode inductive resonant transducer for MiniGrail. We report several quality factor measurements, down to 4.2 K, performed on a scaled size resonator in different conditions: when suspended from a wire and when clamped, by thermal contraction techniques, into a hole of a sphere of 150 mm diameter and 14 kg mass. Q-factor measurements of a first resonator prototype at 4.2 K for MiniGrail are also presented. Finally, a fabrication process for a Nb film pick-up coil is described.

  18. Excitability of guided waves in composites with PWAS transducers

    Science.gov (United States)

    Shen, Yanfeng; Giurgiutiu, Victor

    2015-03-01

    Piezoelectric Wafer Active Sensors (PWAS) are convenient enablers for generating and receiving ultrasonic guided waves. The wide application of composite structures has put new challenges for the Structural Health Monitoring (SHM) and Nondestructive Evaluation (NDE) community due to the general anisotropic behaviors and complicated guided wave features in composites. The excitability of guided waves in composite structures directly influences the implementation of active sensing systems to achieve the best interrogation of certain sensing directions. This paper presents a hybrid modeling technique for studying the excitably of guided waves in composite structures with PWAS transducers. This hybrid technique comprehensively covers local finite element model (FEM), semi-analytical finite element (SAFE) method, and analytical guided wave solutions. Harmonic analysis of a small-size local FEM with non-reflective boundaries (NRB) was carried out for obtaining guided wave generation features in plate structures. The PWAS transducers were modeled with coupled filed elements. Thus, the FEM can fully capture the geometry and material property effects of PWAS transducers and their influence on the guided wave excitation. SAFE method was used to obtain the complicated guided wave features in composites such as dispersion curves and modeshapes. The SAFE procedure was coded into MATLAB Graphical User Interface (GUI), and the software SAFE-DISPERSION was developed. To study the excitability of each wave mode, we considered all the possible wave modes being generated simultaneously and propagating independently. The analytical wave expressions based on the exact guided wave solution with Hankel functions were used to join the SAFE method and the local FEM. Formulated in frequency domain, the hybrid model is highly efficient, providing an over determined equation system for the calculation of mode participation factors. Case studies were carried out: (1) the Lamb wave excitability

  19. Shaft transducer having dc output proportional to angular velocity

    Science.gov (United States)

    Handlykken, M. B. (Inventor)

    1984-01-01

    A brushless dc tachometer is disclosed that includes a high strength toroidal permanent magnet for providing a uniform magnetic field in an air gap, an annular pole piece opposite the magnet, and a pickup coil wound around the pole piece and adapted to rotate about the axis of the pole piece. The pickup coil is rotated by an input shaft to which the coil is coupled with the friction clip. The output of the coil is conducted to circuitry by a twisted wire pair. The input shaft also activates a position transducing potentiometer.

  20. Differential Pressure Transducer for Corrosion Monitoring of Iron

    Directory of Open Access Journals (Sweden)

    Amar Prasad Yadav

    2014-03-01

    Full Text Available In this study, differential pressure transducer (DPT has been applied as an alternate corrosion monitoring device for monitoring corrosion of iron in atmospheric environment by measuring very small changes in the amount of oxygen. The result of corrosion current obtained from DPT method has been compared with that obtained from AC impedance method. The difference in the value of corrosion current obtained from these two methods was attributed to the error in choosing the value of proportionality constant k of the Stern-Geary equation.

  1. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    with the low level of acoustical output power and complex amplifier requirements, have limited the commercial success of the technology. Horn or compression drivers are typically favoured, when high acoustic output power is required, this is however at the expense of significant distortion combined......, the DEAP (Dielectric ElectroActive Polymer) one. DEAP based loudspeakers work on the principle of the electrostatic forces, and possess some of the ii same characteristics as the electrostatic loudspeaker. However, the DEAP transducer is constructed by printing compliant, corrugated electrodes...

  2. New real time needle segmentation technique using grayscale Hough transformation

    Science.gov (United States)

    Qiu, Wu; Zhou, Hua; Ding, Mingyue; Zhang, Songgeng

    2007-12-01

    Real-time needle segmentation and tracking is very important in image-guided surgery, biopsy, and therapy. In this paper, we described an automated technique to provide real-time needle segmentation from a sequence of 2-D ultrasound images for the use of guidance of a needle to the target in soft tissues. The Hough transform is used to find straight lines or analytic curves in binary image. Hough transform is applied usually to binary images. Hence one needs to convert, initially, the gray level image to a binary one (through thresholding, edge detection, or thinning) in order to apply the HT. While in the process of binarization, some information about line segments in the image may be lost when an inappropriate threshold is used. Gray-Scale Hough Transform can detect the line without binarization. Unfortunately, its high computational cost often prevents it from being applied in real-time applications without the help of specially designed hardware. In this paper, we proposed a needle segmentation technique based on a real-time gray-scale Hough transform. It is composed of an improved Gray Hough Transformation and a coarse-fine search strategy. Furthermore, the RTGHT (Real-Time Gray-Scale Hough Transform) technique is evaluated by patient breast biopsy images. Experiments with patient breast biopsy ultrasound (US) image sequences showed that our approach can segment the biopsy needle in real time (i.e., less than 60 ms) with the angular rms error of about 1° and the position rms error of about 0.5 mm an affordable PC computer without the help of specially designed hardware.

  3. Occurrence and knowledge about needle stick injury in nursing students

    International Nuclear Information System (INIS)

    Needle stick injury (NSI) became a major issue and most of the research focuses on Nurses, Doctors and other health care workers, but at the same time nursing students in clinical duties are at high risk. Studies are available which examined NSI only in Medical students and health care workers. The present study is aimed to measure the occurrence of needle stick injury along with post exposure measures and evaluation of the knowledge regarding needle stick injury among nursing student. Methods: A cross-sectional study was conducted in North-East India in 2013. The study participants comprised of 83 nursing students studying in 4th year B.Sc. (N) and 3rd year General Nursing and Midwifery (GNM). Students were questioned regarding their occurrence to Needle Stick Injury throughout their clinical training and measures taken following the exposure. They were also asked to complete the Knowledge questionnaire on NSI. Results: The study among 83 nursing students included 43 (51.81%) GNM 3rd year and 40 (48.19%) B.Sc. Nursing Students. Out of a total 83 students, 75 (90.36%) were females. The occurrence of NSI during their course was reported by 33 (39.76%) participants. The maximum NSI occurred during first year of course (57.57%). It was found that 18 (54.54%) of NSIs were not reported. Among those exposed, only 5 (15.15%) students had undergone blood investigation and very few students took post exposure measures. It was found that, only 23 (69.69%) students were immunized against Hepatitis B before NSI. Conclusion: The present study indicated a high incidence of needle stick injuries among nursing students with more under-reported cases and subjects were not aware of post exposure measures. It is essential to deal above problems by regular training on real-life procedure at the entry level and reporting system should be more user-friendly platform. (author)

  4. Ultrasound-guided core needle biopsy for breast cancer

    International Nuclear Information System (INIS)

    To evaluate the efficacy of ultrasound-guided core needle biopsy (US-CNB) as a preoperative diagnostic modality for breast cancer. Females with solid and/or intermediate breast lesions visualized on ultrasonography. Apart from clinical work-up, all the above mentioned patients underwent ultrasound-guided core needle biopsy and excisional biopsy of their breast lesions. The histopathological diagnosis on ultrasound-guided core needle biopsy was then compared with the findings of the excisional biopsy. Out of the total 93 cases, 47(50.5%) had benign lesions on ultrasound; US-CNB showed 24 as fibroadenomata, four with chronic non-specific mastitis, five chronic suppurative mastitis, one tuberculosis, four fat necrosis, two lactational adenoma and seven cases with benign ductal hyperplasia without atypia. Nine (9.7%) cases showed suspicious abnormality on ultrasound; US-CNB revealed five cases with atypical ductal hyperplasia, one ductal carcinoma in situ and three invasive ductal carcinoma. Thirty seven (39.8%) cases were highly suggestive of malignancy on ultrasound; US-CNB showed 34 as invasive ductal carcinoma, two invasive lobular and one medullary carcinoma. Excisional biopsy confirmed the diagnosis of ultrasound-guided core needle biopsy in all cases except four; one case of chronic suppurative mastitis was diagnosed as that of tuberculosis and three cases of atypial ductal hyperplasia as invasive ductal carcinoma. Hence there was no false positive case, but four (4.3%) false negative cases. The sensitivity of the US-CNB was thus 100% and specificity 91.1%. Ultrasound guided core needle biopsy is a satisfactory procedure for the histopathological diagnosis of breast lesions. Any unsatisfactory, suspicious or atypical change on US-CNB should be followed by an open biopsy. (author)

  5. Design theory and experimental investigation of the low frequency and high power rare earth magnetostrictive flextensional transducer (I). Theoretical part

    Institute of Scientific and Technical Information of China (English)

    HE Xiping; SUN Jincai; LI Bin

    2001-01-01

    The energy relationships among all the elements, by which the magnetostrictive transducers are manufactured, in Finite Element Method (FEM) are analyzed, then the expressions of FEM dynamics equations and performances formulas for magnetostrictive transducers are derived. The vibrating modes of the class VII transducer and its shell vibration are calculated theoretically and the results point out that there is a breathing mode and if the transducer works at this mode, the transducer will vibrate with a greater volume speed and source level.

  6. Performance of transducers with segmented piezoelectric stacks using materials with high electromechanical coupling coefficient

    CERN Document Server

    Thompson, Stephen C; Markley, Douglas C

    2013-01-01

    Underwater acoustic transducers often include a stack of thickness polarized piezoelectric material pieces of alternating polarity interspersed with electrodes, bonded together and electrically connected in parallel. The stack is normally much shorter than a quarter wavelength at the fundamental resonance frequency, so that the mechanical behavior of the transducer is not affected by the segmentation. When the transducer bandwidth is less than a half octave, as has conventionally been the case, stack segmentation has no significant effect on the mechanical behavior of the device. However, when a high coupling coefficient material such as PMN-PT is used to achieve a wider bandwidth, the difference between a segmented stack and a similar piezoelectric section with electrodes only at the two ends can be significant. This paper investigates the effects of stack segmentation on the performance of wideband underwater acoustic transducers, particularly tonpilz transducer elements. Included is discussion of transduce...

  7. Variances and covariances in the Central Limit Theorem for the output of a transducer

    Science.gov (United States)

    Heuberger, Clemens; Kropf, Sara; Wagner, Stephan

    2015-01-01

    We study the joint distribution of the input sum and the output sum of a deterministic transducer. Here, the input of this finite-state machine is a uniformly distributed random sequence. We give a simple combinatorial characterization of transducers for which the output sum has bounded variance, and we also provide algebraic and combinatorial characterizations of transducers for which the covariance of input and output sum is bounded, so that the two are asymptotically independent. Our results are illustrated by several examples, such as transducers that count specific blocks in the binary expansion, the transducer that computes the Gray code, or the transducer that computes the Hamming weight of the width-w non-adjacent form digit expansion. The latter two turn out to be examples of asymptotic independence. PMID:27087727

  8. High frequency PMN-PT single crystal focusing transducer fabricated by a mechanical dimpling technique.

    Science.gov (United States)

    Chen, Y; Lam, K H; Zhou, D; Cheng, W F; Dai, J Y; Luo, H S; Chan, H L W

    2013-02-01

    High frequency (∼30MHz and ∼80MHz) focusing ultrasound transducers were fabricated using a PMN-0.28PT single crystal by a mechanical dimpling technique. The dimpled single crystal was used as an active element for the focusing transducer. Compared with a plane transducer, the focusing transducer fabricated with a dimpled active element exhibits much broader bandwidth and higher sensitivity. Besides, a high quality image can be obtained by the 30MHz focusing transducer, in which the -6dB axial and lateral resolution is 27μm and 139μm, respectively. These results prove that the dimpling technique is capable to fabricate the high frequency focusing transducers with excellent performance for imaging applications. PMID:22944074

  9. 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;

    2014-01-01

    skin blood perfusion response around needle insertion sites. Three common sized pen needles of 28G, 30G, and 32G as well as hooked 32G needles, were inserted into the neck skin of pigs and then removed. Laser Speckle Contrast Analysis was used to measure skin blood perfusion for 20 minutes after...... the insertions. Seven pigs were included in the study and a total of 118 randomized needle insertions were conducted. Histology was made of tissue samples inserted with 18G, 28G, and 32G needles, and stained to quantify red and white blood cell response. Based on area under curve, calculated for each individual...

  10. EXAMPLES OF CLINICAL APPLICATION OF ACUPUNCTURE OF ZHONGWAN (CV 12) WITH ELONGATED NEEDLE

    Institute of Scientific and Technical Information of China (English)

    WU Jian-hua; YAN Li

    2005-01-01

    In the present paper, the authors introduce Professor YAN Li's experience on clinical application of elongated needle for the treatment 12). In addition, they also introduce its operation methods and some points for attention. During operation of the elongated needle, the operator should manipulate it gently, avoiding rude insertion and rash withdrawal; rather, utilize the elasticity of the steel wire to press the needle downward slowly, and cause the favorable needling sensations to spread slowly downward to the affected region along with the movement of the needle body.

  11. Needle Migration to the Heart: An Unusual Association of Hemodialysis and Cardiovascular Morbidity.

    Science.gov (United States)

    Honikman, Rafael; Chikwe, Joanna; Tokita, Joji Erik; Mittnacht, Alexander J C

    2015-10-15

    In this report, we present a unique complication of hemodialysis: the hemodialysis access needle was lost into an arteriovenous fistula. The event went unnoticed for several months. The needle eventually migrated into the right ventricle, requiring an operative retrieval. Loss of the needle was likely unrecognized because of the use of a retracting safety cannula that conceals the needle within a sheath after removal. This case highlights a rare and potentially serious complication of hemodialysis access, demonstrates a possible hazard of retracting safety needles, and reviews the management of foreign bodies that have migrated into the heart.

  12. Use of Macro Fibre Composite Transducers as Acoustic Emission Sensors

    Directory of Open Access Journals (Sweden)

    Mark Eaton

    2009-04-01

    Full Text Available The need for ever lighter and more efficient aerospace structures and components has led to continuous optimization pushing the limits of structural performance. In order to ensure continued safe operation during long term service it is desirable to develop a structural health monitoring (SHM system. Acoustic emission (AE offers great potential for real time global monitoring of aerospace structures, however currently available commercial sensors have limitations in size, weight and adaptability to complex structures. This work investigates the potential use of macro-fibre composite (MFC film transducers as AE sensors. Due to the inhomogeneous make-up of MFC transducers their directional dependency was examined and found to have limited effect on signal feature data. However, signal cross-correlations revealed a strong directional dependency. The sensitivity and signal attenuation with distance of MFC sensors were compared with those of commercially available sensors. Although noticeably less sensitive than the commercial sensors, the MFC sensors still had an acceptable operating range. Furthermore, a series of compressive carbon fiber coupon tests were monitored in parallel using both an MFC sensor and a commercially available sensor for comparison. The results showed good agreement of AE trends recorded by both sensors.

  13. Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration

    Science.gov (United States)

    Saldaña, María; Llorens, Carlos D.; Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    A short bipolar pressure pulse with “pancake” directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter. PMID:27490547

  14. Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration.

    Science.gov (United States)

    Saldaña, María; Llorens, Carlos D; Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    A short bipolar pressure pulse with "pancake" directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter. PMID:27490547

  15. Folding and Function of Proteorhodopsins in Photoenergy Transducing Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Spudich, John L

    2012-08-10

    The overall research objectives are to develop proteorhodopsin (PR) proteins as a model system for {alpha}-helical membrane protein insertion and folding, and to advance understanding of the diversity and mechanisms of PRs, a large family of photoenergy transducers (~4000 identified) abundant in the world’s oceans. Specific aims are: (1) To develop a highefficiency genetic selection procedure for light-driven proton-pumping in E. coli cells. Such a procedure would provide a positive selection method for proper folding and function of PRs in the E. coli membrane. (2) Characterize flash-induced absorption changes and photocurrents in PR variants in organisms from various environments, and their expression level and function when expressed in E. coli. Subaims are to: (a) elucidate the relationship of the transport mechanism to mechanisms of other microbial rhodopsins, some of which like PRs function as ion transporters and some of which use light energy to activate signaling pathways (sensory rhodopsins); and (b) identify important residues and chemical events in light-driven proton transport by PRs. In addition to their importance to the energy of the biosphere PRs have attracted interest for their potential for use in making photoenergy-transducing membranes for bioengineering applications.

  16. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer.

    Science.gov (United States)

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-12-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as polydimethylsiloxane (PDMS), were investigated for an encapsulation material. In addition, PDMS, with a glass-transition temperature below room temperature, provides a low Young's modulus that preserves the static behavior; at higher frequencies for ultrasonic operation, this material becomes stiffer and acoustically matches to water. In this paper, we demonstrate the modeling and implementation of the viscoelastic polymer as the encapsulation material. We introduce a finite element model (FEM) that addresses viscoelasticity. This enables us to correctly calculate both the static operation point and the dynamic behavior of the CMUT. CMUTs designed for medical imaging and therapeutic ultrasound were fabricated and encapsulated. Static and dynamic measurements were used to verify the FEM and show excellent agreement. This paper will help in the design process for optimizing the static and the dynamic behavior of viscoelastic-polymer-coated CMUTs. PMID:21170294

  17. Nonlinear electromechanical response of the ferroelectret ultrasonic transducers

    Science.gov (United States)

    Döring, Joachim; Bovtun, Viktor; Bartusch, Jürgen; Erhard, Anton; Kreutzbruck, Marc; Yakymenko, Yuriy

    2010-08-01

    The ultrasonic transmission between two air-coupled polypropylene (PP) ferroelectret (FE) transducers in dependence on the amplitude of the high-voltage exciting pulse revealed a strongly nonlinear electromechanical response of the FE transmitter. This phenomenon is described by a linear increase of the inverse electromechanical transducer constant t_{33}^{(1)} of the PP FE film with an increase of the exciting electrical pulse amplitude. Enlargement of t_{33}^{(1)} by a factor of 4 was achieved by application of 3500 V exciting pulses. The electrostriction contribution to t_{33}^{(1)} can be attributed to the electrostatic force between electrodes and the Maxwell stress effect. The nonlinear electromechanical properties of the PP FE result in a strong increase of its air-coupled ultrasonic (ACUS) figure of merit ( FOM) under the high-voltage excitation, which exceeds results of the PP FE technological optimization. The FOM increase can be related to the increase of PP FE coupling factor and/or to the decrease of its acoustic impedance. A significant enhancement of the ACUS system transmission (12 dB) and signal-to-noise ratio (32 dB) was demonstrated by the increase of excitation voltage up to 3500 V. The nonlinear electromechanical properties of the PP FEs seem to be very important for their future applications.

  18. Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration.

    Science.gov (United States)

    Saldaña, María; Llorens, Carlos D; Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    A short bipolar pressure pulse with "pancake" directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter.

  19. Numerical modeling of piezoelectric transducers using physical parameters.

    Science.gov (United States)

    Cappon, Hans; Keesman, Karel J

    2012-05-01

    Design of ultrasonic equipment is frequently facilitated with numerical models. These numerical models, however, need a calibration step, because usually not all characteristics of the materials used are known. Characterization of material properties combined with numerical simulations and experimental data can be used to acquire valid estimates of the material parameters. In our design application, a finite element (FE) model of an ultrasonic particle separator, driven by an ultrasonic transducer in thickness mode, is required. A limited set of material parameters for the piezoelectric transducer were obtained from the manufacturer, thus preserving prior physical knowledge to a large extent. The remaining unknown parameters were estimated from impedance analysis with a simple experimental setup combined with a numerical optimization routine using 2-D and 3-D FE models. Thus, a full set of physically interpretable material parameters was obtained for our specific purpose. The approach provides adequate accuracy of the estimates of the material parameters, near 1%. These parameter estimates will subsequently be applied in future design simulations, without the need to go through an entire series of characterization experiments. Finally, a sensitivity study showed that small variations of 1% in the main parameters caused changes near 1% in the eigenfrequency, but changes up to 7% in the admittance peak, thus influencing the efficiency of the system. Temperature will already cause these small variations in response; thus, a frequency control unit is required when actually manufacturing an efficient ultrasonic separation system.

  20. High-resolution diffraction grating interferometric transducer of linear displacements

    Science.gov (United States)

    Shang, Ping; Xia, Haojie; Fei, Yetai

    2016-01-01

    A high-resolution transducer of linear displacements is presented. The system is based on semiconductor laser illumination and a diffraction grating applied as a length master. The theory of the optical method is formulated using Doppler description. The relationship model among the interference strips, measurement errors, grating deflection around the X, Y and Z axes and translation along the Z axis is built. The grating interference strips' direction and space is not changed with movement along the X (direction of grating movement), Y (direction of grating line), Z axis, and the direction and space has a great effect when rotating around the X axis. Moreover the space is little affected by deflection around the Z axis however the direction is changed dramatically. In addition, the strips' position shifted rightward or downwards respectively for deflection around the X or Y axis. Because the emitted beams are separated on the grating plane, the tilt around the X axis error of the stage during motion will lead to the optical path difference of the two beams resulting in phase shift. This study investigates the influence of the tilt around the X axis error. Experiments show that after yaw error compensation, the high-resolution diffraction grating interferometric transducer readings can be significantly improved. The error can be reduced from +/-80 nm to +/-30 nm in maximum.

  1. A stable, sensitive, low-compliance capacitance force transducer.

    Science.gov (United States)

    Hamrell, B B; Panaanan, R; Trono, J; Alpert, N R

    1975-01-01

    The measurement of active and passive force levels in heart muscle requires short-and long-term base-line stability. The capacitance force transducer described here represents an optimization of the relationship between sensitivity, compliance, and frequency response in a design that minimizes long-term base-line drift related to thermal gradients within the apparatus. Thermal stability of the instrument is obtained with the use of quartz and Invar in the construction of the variable capacitor, the maintenance of internal transducer temperature at a constant level well above ambient, and the use of thermally insulating air gaps. Sensitivity ranges from 1.0 to 2.0 V/g wt in the several instruments tested, the output is linear, compliance is negligible with static loads up to 6 g wt, hysteresis is not significant with transient loading with 20 g wt, and long-term drift is greater than or equal to 0.050 g wt. These instruments are designed for use with myocardial preparations but can be adapted for skeletal muscle experiments. PMID:1110237

  2. Numerical Modelling of Mutual Effect among Nearby Needles in a Multi-Needle Configuration of an Atmospheric Air Dielectric Barrier Discharge

    Directory of Open Access Journals (Sweden)

    Xiaoxing Zhang

    2012-05-01

    Full Text Available A numerical study has been conducted to understand the mutual effect among nearby needles in a multi-needle electrode dielectric barrier discharge. In the present paper, a fluid-hydrodynamic model is adopted. In this model, the mutual effect among nearby needles in a multi-needle configuration of an atmospheric air dielectric barrier discharge are investigated using a fluid-hydrodynamic model including the continuity equations for electrons and positive and negative ions coupled with Poisson’s equation. The electric fields at the streamer head of the middle needle (MN and the side needles (SNs in a three-needle model decreased under the influence of the mutual effects of nearby needles compared with that in the single-needle model. In addition, from the same comparison, the average propagation velocities of the streamers from MN and SNs, the electron average energy profile of MN and SNs (including those in the streamer channel, at the streamer head, and in the unbridged gap, and the electron densities at the streamer head of the MN and SNs also decreased. The results obtained in the current paper agreed well with the experimental and simulation results in the literature.

  3. Analysis of eigenfrequencies in piezoelectric transducers using the finite element method

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1988-01-01

    It is noted that the finite-element method is a valuable supplement to the traditional methods for design of novel transducer types because it can determine the vibrational pattern of piezoelectric transducers and is applicable to any geometry. Computer programs for analysis of axisymmetric...... in an efficient way. Examples ranging from a freely vibrating disk to a real focused transducer with a conical backing are presented...

  4. Techniques and physical properties of 10MHz short pulse focused ultrasonic transducer

    Institute of Scientific and Technical Information of China (English)

    ZHU Guozhen; YANG Yong; LU Kean

    2004-01-01

    A focused ultrasonic transducer used for biomedical purposes with a fundamental frequency of 10MHz and a pulse width of one and a half periods is described in this paper. Its physical properties are given including (1) focused acoustic field recorded by an optical means, (2) electric waveform for triggering the transducer and the corresponding waveform of the wave received by another transducer, and (3) result of tests on a sample object.

  5. Advantage analysis of PMN-PT material for free-flooded ring transducers

    Institute of Scientific and Technical Information of China (English)

    He Zheng-Yao; Ma Yuan-Liang

    2011-01-01

    The acoustic radiation characteristics of free-flooded ring transducers made of PZT4 and PMN-PT materials are calculated and compared.First,the theoretical formulae for free-flooded ring transducers are studied.The resonant frequencies of a transducer made of PZT4 and PMN-PT materials are calculated. Then,the transmitting voltage responses of the free-flooded ring transducers are calculated using the finite element method.Finally,the acoustic radiation characteristics of the free-flooded ring transducers are calculated using the boundary element method.The calculated results show that the resonant frequencies of the free-flooded ring transducer made of PMN-PT are greatly reduced compared with those made of PZT4 with the same size.The transmitting voltage response of the transducer made of PMN-PT is much higher than that of the transducer made of PZT4.The calculated 3-dB beamwidth of the acoustic radiated far-field directivity of the free-flooded ring transducer made of PZT4 at the resonant frequency 1900 Hz is 63.6° and that of the transducer made of PMN-PT at the resonant frequency 1000 Hz is 64.6°.The comparison results show that the free-flooded ring transducer made of PMN-PT material has many advantages over that made of PZT4.The PMN-PT is a promising material for improving the performance of free-flooded ring transducers.

  6. Technology trends in high temperature pressure transducers: The impact of micromachining

    Science.gov (United States)

    Mallon, Joseph R., Jr.

    1992-01-01

    This paper discusses the implications of micromachining technology on the development of high temperature pressure transducers. The introduction puts forth the thesis that micromachining will be the technology of choice for the next generation of extended temperature range pressure transducers. The term micromachining is defined, the technology is discussed and examples are presented. Several technologies for high temperature pressure transducers are discussed, including silicon on insulator, capacitive, optical, and vibrating element. Specific conclusions are presented along with recommendations for development of the technology.

  7. Temperature and pressure transducer based on FBG for large diameter water pipes

    OpenAIRE

    Quintela Incera, Antonio; Pallol Pérez, María José; Shokry Girgis Roufael, Hany; Martínez García, Óscar; San Emeterio Diego, José Domingo; López Higuera, José MIguel

    2014-01-01

    A specific temperature and pressure optical fiber transducer is presented in this paper. By using a customized fiber reinforced plastic membrane with embedded Fiber Bragg Gratings, the fluid pressure and temperatures changes are converted in optical wavelength displacements. The membrane and the transducer custom design allows a suitable measurand discrimination. The transducer is implemented, characterized and calibrated. Its feasibility to be used on large diameter water pipes has been succ...

  8. Precision grid and hand motion for accurate needle insertion in brachytherapy

    International Nuclear Information System (INIS)

    Purpose: In prostate brachytherapy, a grid is used to guide a needle tip toward a preplanned location within the tissue. During insertion, the needle deflects en route resulting in target misplacement. In this paper, 18-gauge needle insertion experiments into phantom were performed to test effects of three parameters, which include the clearance between the grid hole and needle, the thickness of the grid, and the needle insertion speed. Measurement apparatus that consisted of two datum surfaces and digital depth gauge was developed to quantify needle deflections. Methods: The gauge repeatability and reproducibility (GR and R) test was performed on the measurement apparatus, and it proved to be capable of measuring a 2 mm tolerance from the target. Replicated experiments were performed on a 23 factorial design (three parameters at two levels) and analysis included averages and standard deviation along with an analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: Results showed that grid with tight clearance hole and slow needle speed increased precision and accuracy of needle insertion. The tight grid was vital to enhance precision and accuracy of needle insertion for both slow and fast insertion speed; additionally, at slow speed the tight, thick grid improved needle precision and accuracy. Conclusions: In summary, the tight grid is important, regardless of speed. The grid design, which shows the capability to reduce the needle deflection in brachytherapy procedures, can potentially be implemented in the brachytherapy procedure.

  9. An effective algorithm for needle tip displacement compensation in robot-assisted percutaneous surgery

    Institute of Scientific and Technical Information of China (English)

    Sun Yinshan; Wu Dongmei; Du Zhijiang; Sun Lining

    2010-01-01

    This paper presents an automatic compensation algorithm for needle tip displacement in order to keep the needle tip always fixed at the skin entry point in the process of needle orientation in robot-assisted percutaneous surgery.The algorithm, based on a two-degree-of-freedom (2-DOF) robot wrist (not the mechanically constrained remote center of motion (RCM) mechanism) and a 3-DOF robot arm, firstly calculates the needle tip displacement caused by rotational motion of robot wrist in the arm coordinate frame using the robotic forward kinematics, and then inversely compensates for the needle tip displace-ment by real-time Cartesian motion of robot arm.The algorithm achieves the function of the RCM and eliminates many mechanical and virtual constraints caused by the RCM mechanism.Experimental result demonstrates that the needle tip displacement is within 1 mm in the process of needle orientation.

  10. Practice and Evaluation: Management of Acupunc-ture Needle Disinfection and Sterilization

    Institute of Scientific and Technical Information of China (English)

    Hui Chen; Hao Huang

    2015-01-01

    Objective: To investigate the necessity and importance of enhancing the sterilization management of acupuncture needles. Methods: Traditionally, acupuncture needles were cleaned manually without thermal disinfec-tion, which often caused needle-stick injuries. To solve the problems, a special cleaning case for acupuncture needles was designed and built to help achieve optimization of the processing flow if the case is used correctly in the process of recycling, cleaning, and package checking. Results: Closed treatment of acupuncture needles reduced the percentage of needle-stick injuries to zero, and centralized management raised patients' satisfaction rate from 93% to 98%. Conclusions: Effective sterilization of acupuncture needles is a precondition for the safe treat-ment of patients. Optimization of the processing flow can ensure the safety of medical personnel and patients; safety is stipulated by relevant regulationsconcerning sterilization and disinfection standards.

  11. [Research thoughts and methodology on efficacy specificity of needling and moxibustion methods based upon data mining].

    Science.gov (United States)

    Jia, Chun-sheng; Li, Xiao-feng; Wang, Jian-ling; Xu, Jing

    2011-02-01

    The method for needling and moxibustion is an indispensable component of acupuncturology. In clinical practice of acupuncture and moxibustion, efficacy specificity of different needling and moxibustion methods for different clinical conditions or different phases of a disease exists objectively, which is in a close relation with the results of clinical interventions. Starting with the correlation between the efficacy specificity of different needling and moxibustion methods and different clinical conditions or syndromes, the authors of the present paper put forward to collect abundant literature on needling and moxibustion methods, extract and analyze standard formats of information, establish literature database on needling and moxibustion methods and then design literature data application platform. On the basis of those mentioned above, a data mining model of needling and moxibustion methods will be established for revealing the potential knowledge and regularities about application of needling and moxibustion methods from the related abundant fuzzy and incomplete literature data according to data analysis and designed research program on efficacy specificity.

  12. Silicon Needles Fabricated by Highly Selective Anisotropic Dry Etching and Their Field Emission Current Characteristics

    Science.gov (United States)

    Kanechika, Masakazu; Mitsushima, Yasuichi

    2000-12-01

    A new process to fabricate a silicon needle, whose tip radius is about 5 nm and aspect ratio is about 7, was developed. The silicon needles were fabricated by highly selective anisotropic dry etching. The etching mask was oxygen precipitation, which was formed by nitrogen ion implantation and the subsequent oxidation. The process is simple enough to be integrated with complementary metal-oxide-semiconductor (CMOS) circuits. The density of the silicon needle can be controlled by adjusting the dose for nitrogen ion implantation. The position of the silicon needle can be controlled by adjusting the position for nitrogen ion implantation, because silicon needles are formed only in the nitrogen ion implantation area. Furthermore, using these silicon needles as micro emitters, a field emission diode was fabricated. The Fowler-Nordheim plot shows that the field around the tip of the silicon needles was highly enhanced.

  13. Toward robotic needle steering in lung biopsy: a tendon-actuated approach

    Science.gov (United States)

    Kratchman, Louis B.; Rahman, Mohammed M.; Saunders, Justin R.; Swaney, Philip J.; Webster, Robert J., III

    2011-03-01

    Needle tip dexterity is advantageous for transthoracic lung biopsies, which are typically performed with rigid, straight biopsy needles. By providing intraoperative compensation for trajectory error and lesion motion, tendon-driven biopsy needles may reach smaller or deeper nodules in fewer attempts, thereby reducing trauma. An image-guided robotic system that uses these needles also has the potential to reduce radiation exposure to the patient and physician. In this paper, we discuss the design, workflow, kinematic modeling, and control of both the needle and a compact and inexpensive robotic prototype that can actuate the tendon-driven needle for transthoracic lung biopsy. The system is designed to insert and steer the needle under Computed Tomography (CT) guidance. In a free-space targeting experiment using a discrete proportional control law with digital camera feedback, we show a position error of less than 1 mm achieved using an average of 8.3 images (n=3).

  14. Observation on Warm Needling Therapy for Third Lumbar Vertebra Transverse Process Syndrome

    Institute of Scientific and Technical Information of China (English)

    Zou Chang-li

    2014-01-01

    Objective: To observe the effect of warm needling therapy plus acupuncture on third lumbar vertebra transverse process syndrome. Methods: Sixty cases of third lumbar vertebra transverseprocess syndrome were randomly divided into a warm needling groupor an acupuncture group, 30 cases in each group. Cases in the acupuncture group were treated by routine points and needle sticking manipulation, while those in the warm needling group were treated by moxibustion plus needling as same as the acupuncture group. Japanese orthopedic association scores (JOA) in the two groups were observed and compared after 2 treatment courses. Results: After treatment, the JOA score in the warm needling group was higher than that in the acupuncture group (P Conclusion: Warm needling therapy is more effective thannormal acupuncture in treating third lumbar vertebra transverseprocess syndrome.

  15. Are needle-free injections a useful alternative for growth hormone therapy in children? Safety and pharmacokinetics of growth hormone delivered by a new needle-free injection device compared to a fine gauge needle.

    NARCIS (Netherlands)

    Dorr, H.G.; Zabransky, S.; Keller, E.; Otten, B.J.; Partsch, C.J.; Nyman, L.; Gillespie, B.K.; Lester, N.R.; Wilson, A.M.; Hyren, C.; Kuijck, M.A. van; Schuld, P.; Schoenfeld, S.L.

    2003-01-01

    The clinical safety, use and pharmacokinetics of a new needle-free device for delivery of growth hormone (GH) were compared with those of conventional needle injection devices. In an open-label, randomized, 4-period crossover study, 18 healthy adults received single subcutaneous injections of Genotr

  16. Cryogenic Clamp-on Ultrasonic Flowmeters using Single Crystal Piezoelectric Transducers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clamp-on ultrasound cryogenic flowmeters using single crystal piezoelectric transducers are proposed to enable reliable, accurate cryogenic instrumentation needs in...

  17. An absolute method for determination of misalignment of an immersion ultrasonic transducer.

    Science.gov (United States)

    Narayanan, M M; Singh, Narender; Kumar, Anish; Babu Rao, C; Jayakumar, T

    2014-12-01

    An absolute methodology has been developed for quantification of misalignment of an ultrasonic transducer using a corner-cube retroreflector. The amplitude based and the time of flight (TOF) based C-scans of the reflector are obtained for various misalignments of the transducer. At zero degree orientation of the transducer, the vertical positions of the maximum amplitude and the minimum TOF in the C-scan coincide. At any other orientation of the transducer with the horizontal plane, there is a vertical shift in the position of the maximum amplitude with respect to the minimum TOF. The position of the minimum (TOF) remains the same irrespective of the orientation of the transducer and hence is used as a reference for any misalignment of the transducer. With the measurement of the vertical shift and the horizontal distance between the transducer and the vertex of the reflector, the misalignment of the transducer is quantified. Based on the methodology developed in the present study, retroreflectors are placed in the Indian 500MWe Prototype Fast Breeder Reactor for assessment of the orientation of the ultrasonic transducer prior to the under-sodium ultrasonic scanning for detection of any protrusion of the subassemblies. PMID:25041979

  18. New improvement of the combined optical fiber transducer for landslide monitoring

    Science.gov (United States)

    Zhu, Z.-W.; Yuan, Q.-Y.; Liu, D.-Y.; Liu, B.; Liu, J.-C.; Luo, H.

    2014-08-01

    Landslide monitoring is important in predicting the behavior of landslides, thereby ensuring environmental, life, and property safety. On the basis of our previous studies, we conducted the double shear test by using a third-generation optical fiber transducer that uses expandable polystyrene (EPS) as base material. However, the third-generation transducer has poor performance when cohesive force is present between the grout and capillary stainless steel pipe of the transducer. Thus, the fourth-generation optical fiber transducer was invented. Similar to the third-generation transducer, the fourth-generation transducer also used EPS as its base material. Single shear test was conducted on the fourth-generation transducer after being grouted with cement mortar (1 : 1 mix ratio). The micro-bend loss mechanism of the optical fiber was considered, and the optical time domain reflectometry instrument was used. The fact that the loss sequence of optical fibers subjected to loading is different at various locations is found. The relationship of the loading-point displacement vs. optical fiber sliding distance and optical loss were measured. Results show that the maximum initial measurement precision of the newly proposed device is 1 mm, the corresponding sliding distance is 21 mm, and the dynamic range is 0-20 mm. The fourth-generation transducer can measure the movement direction of loadings, thus making this transducer applicable for landslide monitoring.

  19. Principle of adaptive optical current transducer on independent variables and its test

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-feng; GUO Zhi-zhong

    2008-01-01

    In order to improve the measurement precision of the optical current transducer (OCT), the adaptive optical transducing principle on independent variables is presented in this paper. And one of the adaptive opti-cal current transducer(AOCT) on the independent variables of the output of the electricmegnet current trans-ducer is introduced. According to IEC660044-8, the performance of AOCT was examined roundly applying the standard testing system authenticated by the state authority. The results indicate that the measurement precision of the AOCT has already reached 0.2 class under the temperature from -40℃ to 60℃,which proves the feasi-bility of the method.

  20. Tunable-angle wedge transducer for improved acoustophoretic control in a microfluidic chip

    DEFF Research Database (Denmark)

    Iranmanesh, I.; Barnkob, Rune; Bruus, Henrik;

    2012-01-01

    coupling angle, and transducer actuation method (single-frequency actuation or frequency-modulation actuation). The energy-density analysis is based on measuring the transmitted light intensity through a microfluidic channel filled with a suspension of 5-μm-diameter beads and the results with the tunable...... particle patterns with average acoustic energy densities comparable to those obtained using single-frequency actuation.......We present a tunable-angle wedge ultrasound transducer for improved control of microparticle acoustophoresis in a microfluidic chip. The transducer is investigated by analyzing the pattern of aligned particles and induced acoustic energy density while varying the system geometry, transducer...