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Sample records for 45-mhz needle transducer

  1. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging

    PubMed Central

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K. Kirk; Kim, Hyung Ham

    2015-01-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast. PMID:25914443

  2. Dual-element needle transducer for intravascular ultrasound imaging

    PubMed Central

    Yoon, Sangpil; Kim, Min Gon; Williams, Jay A.; Yoon, Changhan; Kang, Bong Jin; Cabrera-Munoz, Nestor; Shung, K. Kirk; Kim, Hyung Ham

    2015-01-01

    Abstract. A dual-element needle transducer for intravascular ultrasound imaging has been developed. A low-frequency element and a high-frequency element were integrated into one device to obtain images which conveyed both low- and high-frequency information from a single scan. The low-frequency element with a center frequency of 48 MHz was fabricated from the single crystal form of lead magnesium niobate-lead titanate solid solution with two matching layers (MLs) and the high frequency element with a center frequency of 152 MHz was fabricated from lithium niobate with one ML. The measured axial and lateral resolutions were 27 and 122  μm, respectively, for the low-frequency element, and 14 and 40  μm, respectively, for the high-frequency element. The performance of the dual-element needle transducer was validated by imaging a tissue-mimicking phantom with lesion-mimicking area, and ex vivo rabbit aortas in water and rabbit whole blood. The results suggest that a low-frequency element effectively provides depth resolved images of the whole vessel and its adjacent tissue, and a high-frequency element visualizes detailed structure near the surface of the lumen wall in the presence of blood within the lumen. The advantages of a dual-element approach for intravascular imaging are also discussed. PMID:26158118

  3. HIFU Transducer Characterization Using a Robust Needle Hydrophone

    NASA Astrophysics Data System (ADS)

    Howard, Samuel M.; Zanelli, Claudio I.

    2007-05-01

    A robust needle hydrophone has been developed for HIFU transducer characterization and reported on earlier. After a brief review of the hydrophone design and performance, we demonstrate its use to characterize a 1.5 MHz, 10 cm diameter, F-number 1.5 spherically focused source driven to exceed an intensity of 1400 W/cm2at its focus. Quantitative characterization of this source at high powers is assisted by deconvolving the hydrophone's calibrated frequency response in order to accurately reflect the contribution of harmonics generated by nonlinear propagation in the water testing environment. Results are compared to measurements with a membrane hydrophone at 0.3% duty cycle and to theoretical calculations, using measurements of the field at the source's radiating surface as input to a numerical solution of the KZK equation.

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

    PubMed

    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

  5. Photoacoustic imaging of clinical metal needle by a LED light source integrated transducer

    NASA Astrophysics Data System (ADS)

    Agano, Toshitaka; Sato, Naoto; Nakatsuka, Hitoshi; Kitagawa, Kazuo; Hanaoka, Takamitsu; Morisono, Koji; Shigeta, Yusuke; Tanaka, Chizuyo

    2016-03-01

    We have achieved penetration depth of 30mm by photoacoustic imaging system using LED light source integrated transducer to image a clinical metal needle inserted into a tissue mimicking phantom. We developed the transducer that integrated near-infrared LED array light source, which was connected to a photoacoustic imaging system which drove LED array light source and controlled photoacoustic data acquisition process. Conventionally solid-state laser has been used as the light source for photoacoustic imaging system. Because LED is diffused light source, laser safety glasses is not necessary, also inflexible fibers are not used to guide light close to a transducer, and we integrated LED light source inside the transducer, which became compact and practical size for conventional ultrasound equipment users. We made LED light source unit as detachable to the transducer easily, so wave-length of light can be selectable by changing the LED light source unit.

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

    PubMed Central

    Chen, Ruimin; Tsui, Po-Hsiang; Zhou, Qifa; Humayun, Mark S; Shung, K Kirk

    2010-01-01

    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−1 MHz−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. PMID:19759408

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

    NASA Astrophysics Data System (ADS)

    Huang, Chih-Chung; Chen, Ruimin; Tsui, Po-Hsiang; Zhou, Qifa; Humayun, Mark S.; Shung, K. Kirk

    2009-10-01

    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-1 MHz-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.

  8. Cataract measurement by estimating the ultrasonic statistical parameter using an ultrasound needle transducer: an in vitro study

    PubMed Central

    Huang, Chih-Chung; Zhou, Qifa; Shung, K Kirk

    2011-01-01

    A cataract is a clouding of the crystalline lens that reduces the amount of incoming light and impairs visual perception. Phacoemulsification is the most common surgical method for treating advanced cataracts, and the optimal phacoemulsification energy is determined by the lens hardness. A previous study proposed using the ultrasonic Nakagami image to complement the B-scan for distinguishing different degrees of lens hardening. However, it is difficult to implement the use of an imaging probe to detect the lens during phacoemulsification surgery in a clinical situation. To resolve this problem, this study applied an ultrasonic needle transducer to estimate the Nakagami parameter as an alternative for characterizing the cataract lens. Cataracts of porcine lenses were artificially induced in vitro, and the Young’s modulus, backscattering intensities, and the Nakagami parameters were measured. The results showed that the backscattering intensity was not correlated with Young’s modulus. In contrast, the average Nakagami parameter increased from 0.34 to 0.95 with increasing Young’s modulus of the lens from 1.71 to 101 kPa. The above findings showed that the Nakagami parameter estimated with a needle transducer may be useful in differentiating different degrees of lens hardening, and implied that determining the optimal ultrasonic energy during clinical cataract surgery is possible if the needle transducer can be combined with the phacoemulsification probe to estimate the Nakagami parameter. PMID:21422512

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

    PubMed Central

    Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

    2014-01-01

    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. PMID:25254305

  10. Analysis of Bromination of Ethylbenzene Using a 45 MHz NMR Spectrometer: An Undergraduate Organic Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Isaac-Lam, Meden F.

    2014-01-01

    A 45 MHz benchtop NMR spectrometer is used to identify the structures and determine the amount of 1-bromoethylbenzene and 1,1-dibromoethylbenzene produced from free-radical bromination of ethylbenzene. The experiment is designed for nonchemistry majors, specifically B.S. Biology students, in a predominantly undergraduate institution with…

  11. Transducer characterization

    SciTech Connect

    Cross, B. T.; Eoff, J. M.; Schuetz, L. J.; Cunningham, K. R.

    1980-07-02

    This report has been prepared specifically for ultrasonic transducer users within the Nondestructive Testing Evaluation (NDE) community of the weapons complex. The purpose of the report is to establish an initial set of uniform procedures for measuring and recording transducer performance data, and to establish a common foundation on which more comprehensive transducer performance evaluations may be added as future transducer performance criteria expands. Transducer parameters and the problems with measuring them are discussed and procedures for measuring transducer performance are recommended with special precautionary notes regarding critical aspects of each measurement. An important consideration regarding the recommended procedures is the cost of implementation. There are two distinct needs for transducer performance characterization in the complex. Production oriented users need a quick, reliable means to check a transducer to ascertain its suitability for continued service. Development groups and the Transducer Center need a comprehensive characterization means to collect adequate data to evaluate theoretical concepts or to build exact replacement transducers. The instrumentation, equipment, and procedures recommended for monitoring production transducers are utilitarian and provide only that information needed to determine transducer condition.

  12. Microinterferometer transducer

    DOEpatents

    Corey, III, Harry S.

    1979-01-01

    An air-bearing microinterferometer transducer is provided for increased accuracy, range and linearity over conventional displacement transducers. A microinterferometer system is housed within a small compartment of an air-bearing displacement transducer housing. A movable cube corner reflector of the interferometer is mounted to move with the displacement gauging probe of the transducer. The probe is disposed for axial displacement by means of an air-bearing. Light from a single frequency laser is directed into an interferometer system within the transducer housing by means of a self-focusing fiber optic cable to maintain light coherency. Separate fringe patterns are monitored by a pair of fiber optic cables which transmit the patterns to a detecting system. The detecting system includes a bidirectional counter which counts the light pattern fringes according to the direction of movement of the probe during a displacement gauging operation.

  13. Single-Camera Closed-Form Real-Time Needle Tracking for Ultrasound-Guided Needle Insertion.

    PubMed

    Najafi, Mohammad; Abolmaesumi, Purang; Rohling, Robert

    2015-10-01

    Many common needle intervention procedures are performed with ultrasound guidance because it is a flexible, cost-effective and widely available intra-operative imaging modality. In a needle insertion procedure with ultrasound guidance, real-time calculation and visualization of the needle trajectory can help to guide the choice of puncture site and needle angle to reach the target depicted in the ultrasound image. We found that it is feasible to calculate the needle trajectory with a single camera mounted directly on the ultrasound transducer by using the needle markings. Higher accuracy is achieved compared with other similar transducer-mounted needle trackers. We used an inexpensive, real-time and easy-to-use tracking method based on an automatic feature extraction algorithm and a closed-form method for pose estimation of the needle. The overall accuracy was 0.94 ± 0.46 mm. PMID:26215491

  14. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  15. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  16. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  17. Ultrasonic transducer

    SciTech Connect

    Taylor, Steven C.; Kraft, Nancy C.

    2007-03-13

    An ultrasonic transducer having an effective center frequency of about 42 MHz; a bandwidth of greater than 85% at 6 dB; a spherical focus of at least 0.5 inches in water; an F4 lens; a resolution sufficient to be able to detect and separate a 0.005 inch flat-bottomed hole at 0.005 inches below surface; and a beam size of approximately 0.006–0.008 inches measured off a 11/2 mm ball in water at the transducer's focal point.

  18. Acoustic Radiation Force Impulse (ARFI) Imaging-Based Needle Visualization

    PubMed Central

    Rotemberg, Veronica; Palmeri, Mark; Rosenzweig, Stephen; Grant, Stuart; Macleod, David; Nightingale, Kathryn

    2011-01-01

    Ultrasound-guided needle placement is widely used in the clinical setting, particularly for central venous catheter placement, tissue biopsy and regional anesthesia. Difficulties with ultrasound guidance in these areas often result from steep needle insertion angles and spatial offsets between the imaging plane and the needle. Acoustic Radiation Force Impulse (ARFI) imaging leads to improved needle visualization because it uses a standard diagnostic scanner to perform radiation force based elasticity imaging, creating a displacement map that displays tissue stiffness variations. The needle visualization in ARFI images is independent of needle-insertion angle and also extends needle visibility out of plane. Although ARFI images portray needles well, they often do not contain the usual B-mode landmarks. Therefore, a three-step segmentation algorithm has been developed to identify a needle in an ARFI image and overlay the needle prediction on a coregistered B-mode image. The steps are: (1) contrast enhancement by median filtration and Laplacian operator filtration, (2) noise suppression through displacement estimate correlation coefficient thresholding and (3) smoothing by removal of outliers and best-fit line prediction. The algorithm was applied to data sets from horizontal 18, 21 and 25 gauge needles between 0–4 mm offset in elevation from the transducer imaging plane and to 18G needles on the transducer axis (in plane) between 10° and 35° from the horizontal. Needle tips were visualized within 2 mm of their actual position for both horizontal needle orientations up to 1.5 mm off set in elevation from the transducer imaging plane and on-axis angled needles between 10°–35° above the horizontal orientation. We conclude that segmented ARFI images overlaid on matched B-mode images hold promise for improved needle visibility in many clinical applications. PMID:21608445

  19. Ultrasound guided spine needle insertion

    NASA Astrophysics Data System (ADS)

    Chen, Elvis C. S.; Mousavi, Parvin; Gill, Sean; Fichtinger, Gabor; Abolmaesumi, Purang

    2010-02-01

    An ultrasound (US) guided, CT augmented, spine needle insertion navigational system is introduced. The system consists of an electromagnetic (EM) sensor, an US machine, and a preoperative CT volume of the patient anatomy. Three-dimensional (3D) US volume is reconstructed intraoperatively from a set of two-dimensional (2D) freehand US slices, and is coregistered with the preoperative CT. This allows the preoperative CT volume to be used in the intraoperative clinical coordinate. The spatial relationship between the patient anatomy, surgical tools, and the US transducer are tracked using the EM sensor, and are displayed with respect to the CT volume. The pose of the US transducer is used to interpolate the CT volume, providing the physician with a 2D "x-ray vision" to guide the needle insertion. Many of the system software components are GPU-accelerated, allowing real-time performance of the guidance system in a clinical setting.

  20. Pressure transducer

    DOEpatents

    Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Gunchin, Elmer R.

    1989-01-01

    A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output.

  1. PRESSURE TRANSDUCER

    DOEpatents

    Sander, H.H.

    1959-10-01

    A pressure or mechanical force transducer particularly adaptable to miniature telemetering systems is described. Basically the device consists of a transistor located within a magnetic field adapted to change in response to mechanical force. The conduction characteristics of the transistor in turn vary proportionally with changes in the magnetic flux across the transistor such that the output (either frequency of amplitude) of the transistor circuit is proportional to mechanical force or pressure.

  2. Pressure transducer

    DOEpatents

    Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Gunchin, E.R.

    1987-02-13

    A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output. 7 figs.

  3. Multifunctional transducer

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Culler, V. H.; Merrbaum, S. (Inventor)

    1981-01-01

    Several parameters of a small region of a muscle tissue or other object, can be simultaneously measured using with minimal traumatizing or damage of the object, a trifunctional transducer which can determine the force applied by a muscle fiber, the displacement of the fiber, and the change in thickness of the fiber. The transducer has three legs with inner ends joined together and outer ends formed to piece the tissue and remain within it. Two of the legs are relatively stiff, to measure force applied by the tissue, and a third leg is relatively flexible to measure displacement of the tissue relative to one or both stiff legs, and with the three legs lying in a common plane so that the force and displacement measurements all relate to the same direction of muscle movements. A flexible loop is attached to one of the stiff legs to measure changes in muscle thickness, with the upper end of the loop fixed to the leg and the lower end of the loop bearing against the surface of the tissue and being free to slide on the leg.

  4. Effects of vibration excitation methodology and configuration of an acoustic needle on its tip vibration.

    PubMed

    Li, Ning; Hu, Junhui

    2013-04-01

    One of design purposes of an acoustic needle is to obtain a big vibration displacement at its tip. In this paper, vibration characteristics of the tip of the acoustic needle driven by a sandwich type ultrasonic transducer, is investigated to obtain the guidelines for increasing the tip vibration. It is found that the tip vibration can be increased by employing acoustic needles with proper vibration excitation structure and configuration. The effective measures include using a sandwich type piezoelectric transducer with flexurally vibrating end plates and an acoustic needle with conical tip section, decreasing the length of vibration excitation section at the needle root, bonding the needle root at a proper location of the transducer end plate, and tuning the length ratio of the conical tip section to the whole needle. PMID:23294988

  5. Needle Phobia.

    PubMed

    Cook, Lynda S

    2016-01-01

    Venipuncture is generally associated with some degree of pain, discomfort, and/or apprehension. Yet most patients accept it with tolerance, even nonchalance. A few, not only pediatric patients, exhibit a higher degree of anxiety and face the procedure with tears, tension, and a variety of bargaining techniques (ie, stick on the count of 3; use only this vein). But for 1 group of people, venipuncture is associated with such fear that avoidance of the procedure is practiced. The end results are detrimental to the patient and may have an impact on society as well. These are patients the American Psychiatric Association classifies as needle phobic. What can a nurse with no training in psychiatry do to assist these patients? To form an appropriate professional response, it's beneficial for practitioners to recognize the different pathways that lead to needle phobia and the issues related to the disorder. PMID:27598066

  6. Modelling and characterisation of a ultrasound-actuated needle for improved visibility in ultrasound-guided regional anaesthesia and tissue biopsy.

    PubMed

    Kuang, Y; Hilgers, A; Sadiq, M; Cochran, S; Corner, G; Huang, Z

    2016-07-01

    Clear needle visualisation is recognised as an unmet need for ultrasound guided percutaneous needle procedures including regional anaesthesia and tissue biopsy. With inadequate needle visibility, these procedures may result in serious complications or a failed operation. This paper reports analysis of the modal behaviour of a previously proposed ultrasound-actuated needle configuration, which may overcome this problem by improving needle visibility in colour Doppler imaging. It uses a piezoelectric transducer to actuate longitudinal resonant modes in needles (outer diameter 0.8-1.2mm, length>65mm). The factors that affect the needle's vibration mode are identified, including the needle length, the transducer's resonance frequency and the gripping position. Their effects are investigated using finite element modelling, with the conclusions validated experimentally. The actuated needle was inserted into porcine tissue up to 30mm depth and its visibility was observed under colour Doppler imaging. The piezoelectric transducer is able to generate longitudinal vibration with peak-to-peak amplitude up to 4μm at the needle tip with an actuating voltage of 20Vpp. Actuated in longitudinal vibration modes (distal mode at 27.6kHz and transducer mode at 42.2kHz) with a drive amplitude of 12-14Vpp, a 120mm needle is delineated as a coloured line in colour Doppler images, with both needle tip and shaft visualised. The improved needle visibility is maintained while the needle is advanced into the tissue, thus allowing tracking of the needle position in real time. Moreover, the needle tip is highlighted by strong coloured artefacts around the actuated needle generated by its flexural vibration. A limitation of the technique is that the transducer mode requires needles of specific lengths so that the needle's resonance frequency matches the transducer. This may restrict the choice of needle lengths in clinical applications. PMID:27022669

  7. Steerable real-time sonographically guided needle biopsy.

    PubMed

    Buonocore, E; Skipper, G J

    1981-02-01

    A method for dynamic real-time ultrasonic guidance for percutaneous needle biopsy has been successful in obtaining cytologic and histologic specimens from abdominal masses. The system depends on a real-time ultrasonic transducer that has been rigidly attached to a laterally placed steerable needle holder. Using simple trigonometric functions, a chart has been derived that gives the exact angulation and needle length to produce quick, reliable, guided needle placements. Examples of successful renal, hepatobiliary, and retroperitoneal biopsies are presented. Advantages of this technique include speed, accuracy, low cost, three-dimensional format, and the omission of contrast media and radiation. PMID:6781264

  8. Measurement of the total acoustic output power of HITU transducers

    NASA Astrophysics Data System (ADS)

    Jenderka, Klaus-V.; Beissner, Klaus

    2010-03-01

    The majority of High Intensity Therapeutic Ultrasound (HITU) applications use strongly focused ultrasound fields generating very high local intensities in the focal region. The metrology of these high-power ultrasound fields is a challenge for the established measurement procedures and devices. This paper describes the results of measurements by means of the radiation force for a total acoustic output power up to 400 W at 1.5 MHz and up to 200 W at 2.45 MHz. For this purpose, a radiation force balance set-up was adapted for the determination of large acoustic output powers. For two types of HITU transducers, the relationship between the total acoustic output power and the applied net electrical power was determined at close transducer-target distance. Further, dependence of the measured electro-acoustic radiation conductance on the transducer-target distance was investigated at reduced power levels, considering the appearance of focal anomalies. Concluding, a list of the main uncertainty contributions, and an estimate of the uncertainty for the used radiation force balance set-up is given for measurements at high power levels.

  9. Transducer-Mounting Fixture

    NASA Technical Reports Server (NTRS)

    Spiegel, Kirk W.

    1990-01-01

    Transducer-mounting fixture holds transducer securely against stud. Projects only slightly beyond stud after installation. Flanged transducer fits into fixture when hinged halves open. When halves reclosed, fixture tightened onto threaded stud until stud makes contact with transducer. Knurled area on fixture aids in tightening fixture on stud.

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

    PubMed

    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

  11. Optical measuring displacement transducers

    NASA Astrophysics Data System (ADS)

    Dich, L. Z.

    1994-09-01

    Trends in the development and production of photoelectric displacement transducers are analyzed. The technical characteristics of certain transducers are briefly presented. A table of comparisons is given, based on available information sources.

  12. Transducer applications, a compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The characteristics and applications of transducers are discussed. Subjects presented are: (1) thermal measurements, (2) liquid level and fluid flow measurements, (3) pressure transducers, (4) stress-strain measurements, (5) acceleration and velocity measurements, (6) displacement and angular rotation, and (7) transducer test and calibration methods.

  13. Phase insensitive acoustoelectric transducer

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1978-01-01

    Conventional ultrasonic transducers transform acoustic waves into electrical signals preserving phase and amplitude information. When the acoustic wavelength is significantly smaller than the transducer diameter, severe phase modulation of the electrical signal can occur. This results in anomalous attenuation measurements, background noise in nondestructive evaluation, and in general complicates data interpretation. This article describes and evaluates a phase-insensitive transducer based on the acoustoelectric effect. Theory of operation of the acoustoelectric transducer (AET) is discussed, and some optimization procedures outlined for its use. Directivity data for the AET are contrasted with a conventional piezoelectric transducer. In addition, transmission scanning data of phantom flaws in metal plates are presented for both transducers and demonstrate a significant improvement in resolution with the AET.

  14. Ultrasensitive ultrasonic transducer studies

    SciTech Connect

    Dixon, R.; Darling, T.; Migliori, A.

    1996-09-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to continue development of the ultrasensitive ultrasonic transducers that won a 1994 R&D 100 Award. These transducers have a very smooth response across a broad frequency range and thus are extremely well- suited for resonant ultrasound spectroscopy as well as pulsed-echo and acoustic-emission applications. Current work on these transducers has indicated that bonding the piezoelectric and wear surface to a metal foil and attaching the foil to a body is less expensive and produces a transducer that is as good or better than commercially produced transducers. We have diffusion- bonded piezoelectric crystals and backings to stainless-steel-foil and wear surfaces. These are then attached onto stainless-steel tubes with electrical connectors to form the transducers. The transducers have been characterized using a reciprocity technique, electrical response, and optical interferometry. After characterization, the transducers have been compared to existing transducers by measuring and testing identical properties.

  15. Experiments with Ultrasonic Transducers.

    ERIC Educational Resources Information Center

    Greenslade, Thomas R., Jr.

    1994-01-01

    Discusses the use of 40 kHz ultrasonic transducers to study wave phenomena. Determines that the resulting wavelength of 9 mm allows acoustic experiments to be performed on a tabletop. Includes transducer characteristics and activities on speed of sound, reflection, double- and single-slit diffraction, standing waves, acoustical zone plate, and…

  16. Crossflow force transducer. [LMFBR

    SciTech Connect

    Mulcahy, T M

    1982-05-01

    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.

  17. [Intrapulmonary Sewing Needle].

    PubMed

    Hisama, Naoya; Tsunemitsu, Nobumasa; Yasumasu, Tetsuo; Yamasaki, Takashi; Uchida, Takahisa

    2016-06-01

    Intrapulmonary aberrant needles are rarely encountered in clinical practice. A 82-year-old woman, though she was asymptomatic, was referred to our department due to an abnormal shadow on a chest X-ray. Chest X-ray and chest computed tomography showed a foreign body suspected to be a sewing needle in the left upper lobe. The needle was successfully removed by video-assisted thoracoscopic surgery. PMID:27246130

  18. Precessing Ferromagnetic Needle Magnetometer

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  19. Precessing Ferromagnetic Needle Magnetometer.

    PubMed

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

    2016-05-13

    A ferromagnetic needle is predicted to precess about the magnetic field axis at a Larmor frequency Ω under conditions where its intrinsic spin dominates over its rotational angular momentum, Nℏ≫IΩ (I is the moment of inertia of the needle about the precession axis and N is the number of polarized spins in the needle). In this regime the needle behaves as a gyroscope with spin Nℏ maintained along the easy axis of the needle by the crystalline and shape anisotropy. A precessing ferromagnetic needle is a correlated system of N spins which can be used to measure magnetic fields for long times. In principle, by taking advantage of rapid averaging of quantum uncertainty, the sensitivity of a precessing needle magnetometer can far surpass that of magnetometers based on spin precession of atoms in the gas phase. Under conditions where noise from coupling to the environment is subdominant, the scaling with measurement time t of the quantum- and detection-limited magnetometric sensitivity is t^{-3/2}. The phenomenon of ferromagnetic needle precession may be of particular interest for precision measurements testing fundamental physics. PMID:27232012

  20. [Atraumatic needles for cataract surgery].

    PubMed

    Harnisch, J P

    1985-12-01

    The author reports on his experience with spatula needles and cutting needles with micropoint in cataract surgery. Configuration and edge treatment of the different needles were demonstrated by scanning electron microscope. The characteristics of the tested needles seem to depend mainly upon their profile. In cataract surgery the spatula needles proved to be superior to the needles with cutting micropoint due to their ski-shaped design. PMID:3912601

  1. Modeling, Production, and Testing of an Echogenic Needle for Ultrasound-Guided Nerve Blocks.

    PubMed

    Bigeleisen, Paul E; Hess, Aaron; Zhu, Richard; Krediet, Annelot

    2016-06-01

    We have designed, produced, and tested an echogenic needle based on a sawtooth pattern where the height of the tooth was 1.25 times the wavelength of the ultrasound transducer. A numeric solution to the time-independent wave equation (Helmholtz equation) was used to create a model of backscattering from a needle. A 21-gauge stainless steel prototype was manufactured and tested in a water bath. Backscattering from the needle was compared to theoretical predications from our model. Based on these results, an 18-gauge prototype needle was fabricated from stainless steel and tested in a pig cadaver. This needle was compared to a commercial 18-gauge echogenic needle (Pajunk Medical Systems, Tucker, GA) by measuring the brightness of the needle relative to the background of sonograms of a needle in a pig cadaver. The backscattering from the 21-gauge prototype needle reproduced the qualitative predictions of our model. At 30° and 45° of insonation, our prototype performed equivalently to the Pajunk needle. At 60°, our prototype was significantly brighter than the Pajunk needle (P = .017). In conclusion, we chose a model for the design of an echogenic needle and modeled it on the basis of a solution to the Helmholtz equation. A prototype needle was tested in a water bath and compared to the model prediction. After verification of our model, we designed an 18-gauge needle, which performed better than an existing echogenic needle (Pajunk) at 60° of insonation. Our needle will require further testing in human trials. PMID:27162281

  2. Spark ultrasonic transducer

    NASA Technical Reports Server (NTRS)

    Hoop, J. M.

    1972-01-01

    Nondestructive testing by spark transducer induces ultrasonic pulses in materials without physical contact. High power pulse generator connected to step up transformer produces sparking between two tungsten rods and ultrasonic energy pulses in test samples placed between rods.

  3. Improved myocardium transducer

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    Method of implanting myocardium transducer uses special indented pins that are caught and securely held by epicardial fibers. Pins are small enough to cause minimum of trauma to myocardium during implantation or removal.

  4. Microfiber interferometric acoustic transducers.

    PubMed

    Wang, Xiuxin; Jin, Long; Li, Jie; Ran, Yang; Guan, Bai-Ou

    2014-04-01

    Acoustic and ultrasonic transducers are key components in biomedical information technology, which has been applied in medical diagnosis, photoacoustic endoscopy and photoacoustic imaging. In this paper, an acoustic transducer based on Fabry-Perot interferometer (FPI) fabricated in a microscaled optical fiber is demonstrated. The transducer is fabricated by forming two wavelength-matched Bragg gratings into the microfiber by means of side illumination with a 193nm excimer laser. When placing the transducer in water, the applied acoustic signal periodically changes the refractive index (RI) of the surrounding liquid and modulates the transmission of the FPI based on the evanescent-field interaction between the liquid and the transmitting light. As a result, the acoustic signal can be constructed with a tunable laser whose output wavelength is located at the slope of the inteferometric fringes. The transducer presents a sensitivity of 10 times higher than the counterparts fabricated in conventional singlemode fibers and has great potential to achieve higher resolution for photoacoustic imaging due to its reduced diameter. PMID:24718189

  5. Pleural needle biopsy

    MedlinePlus

    ... et al, eds. Murray and Nadel's Textbook of Respiratory Medicine . 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 19. Ly A. Fine-needle aspiration biopsy technique and specimen ... Respiratory system. In: Watson N. Chapman and Nakielny's Guide ...

  6. Intracerebral sewing needle.

    PubMed

    Yolas, C; Aydin, M D; Ozdikici, M; Aydin, N; Onder, A

    2007-01-01

    A 9-year-old male patient complaining of seizure attack was admitted to the neurosurgery department. Radiologic investigations revealed a 5-cm-long metallic sewing needle extending from the right frontal cortex to the right lateral ventricle. Burr hole surgery was performed and the needle was grasped with biopsy forceps and removed with endoscopic guidance. The patient recovered without any complications. PMID:17786012

  7. Miniature biaxial strain transducer

    NASA Technical Reports Server (NTRS)

    Hoffman, I. S. (Inventor)

    1976-01-01

    A reusable miniature strain transducer for use in the measurement of static or quasi-static, high level, biaxial strain on the surface of test specimens or structures was studied. Two cantilever arms, constructed by machining the material to appropriate flexibility, are self-aligning and constitute the transducing elements of the device. Used in conjunction with strain gages, the device enables testing beyond normal gage limits for high strains and number of load cycles. The device does not require conversion computations since the electrical output of the strain gages is directly proportional to the strain measured.

  8. Glass-windowed ultrasound transducers.

    PubMed

    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

  9. Broadband Ultrasonic Transducers

    NASA Technical Reports Server (NTRS)

    Heyser, R. C.

    1986-01-01

    New geometry spreads out resonance region of piezoelectric crystal. In new transducer, crystal surfaces made nonparallel. One surface planar; other, concave. Geometry designed to produce nearly uniform response over a predetermined band of frequencies and to attenuate strongly frequencies outside band. Greater bandwidth improves accuracy of sonar and ultrasonic imaging equipment.

  10. Ultrasonic Transducer Analyzer

    NASA Technical Reports Server (NTRS)

    Grounds, M. K.

    1982-01-01

    Ultrasonic transducer-beam-intensity distributions are determined by analyzing echoes from a spherical ball. Computers control equipment and process data. Important beam characteristics, such as location of best beam focus and beam diameter at focus, can be determined quickly from extensive set of plots generated by apparatus.

  11. Inertia diaphragm pressure transducer

    NASA Technical Reports Server (NTRS)

    Seegmiller, H. L. B.

    1971-01-01

    Transducer measures gas pressure profiles in high temperature, short duration, gas flows usually found in devices where pressure pulses may have durations of few microseconds to several milliseconds. Assembly includes fluid delay line, delay chamber, and flow restrictor for equalizing steady state pressure on diaphragm's sides

  12. Oblique needle segmentation and tracking for 3D TRUS guided prostate brachytherapy

    SciTech Connect

    Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

    2005-09-15

    An algorithm was developed in order to segment and track brachytherapy needles inserted along oblique trajectories. Three-dimensional (3D) transrectal ultrasound (TRUS) images of the rigid rod simulating the needle inserted into the tissue-mimicking agar and chicken breast phantoms were obtained to test the accuracy of the algorithm under ideal conditions. Because the robot possesses high positioning and angulation accuracies, we used the robot as a ''gold standard,'' and compared the results of algorithm segmentation to the values measured by the robot. Our testing results showed that the accuracy of the needle segmentation algorithm depends on the needle insertion distance into the 3D TRUS image and the angulations with respect to the TRUS transducer, e.g., at a 10 deg. insertion anglulation in agar phantoms, the error of the algorithm in determining the needle tip position was less than 1 mm when the insertion distance was greater than 15 mm. Near real-time needle tracking was achieved by scanning a small volume containing the needle. Our tests also showed that, the segmentation time was less than 60 ms, and the scanning time was less than 1.2 s, when the insertion distance into the 3D TRUS image was less than 55 mm. In our needle tracking tests in chicken breast phantoms, the errors in determining the needle orientation were less than 2 deg. in robot yaw and 0.7 deg. in robot pitch orientations, for up to 20 deg. needle insertion angles with the TRUS transducer in the horizontal plane when the needle insertion distance was greater than 15 mm.

  13. Future needs for biomedical transducers

    NASA Technical Reports Server (NTRS)

    Wooten, F. T.

    1971-01-01

    In summary there are three major classes of transducer improvements required: improvements in existing transducers, needs for unexploited physical science phenomena in transducer design, and needs for unutilized physiological phenomena in transducer design. During the next decade, increasing emphasis will be placed on noninvasive measurement in all of these areas. Patient safety, patient comfort, and the need for efficient utilization of the time of both patient and physician requires that noninvasive methods of monitoring be developed.

  14. Needle Federated Search Engine

    Energy Science and Technology Software Center (ESTSC)

    2009-12-01

    The Idaho National Laboratory (INL) has combined a number of technologies, tools, and resources to accomplish a new means of federating search results. The resulting product is a search engine called Needle, an open-source-based tool that the INL uses internally for researching across a wide variety of information repositories. Needle has a flexible search interface that allows end users to point at any available data source. A user can select multiple sources such as commercialmore » databases (Web of Science, Engineering Index), external resources (WorldCat, Google Scholar), and internal corporate resources (email, document management system, library collections) in a single interface with one search query. In the future, INL hopes to offer this open-source engine to the public. This session will outline the development processes for making Needle™s search interface and simplifying the federation of internal and external data sources.« less

  15. Needle Federated Search Engine

    SciTech Connect

    2009-12-01

    The Idaho National Laboratory (INL) has combined a number of technologies, tools, and resources to accomplish a new means of federating search results. The resulting product is a search engine called Needle, an open-source-based tool that the INL uses internally for researching across a wide variety of information repositories. Needle has a flexible search interface that allows end users to point at any available data source. A user can select multiple sources such as commercial databases (Web of Science, Engineering Index), external resources (WorldCat, Google Scholar), and internal corporate resources (email, document management system, library collections) in a single interface with one search query. In the future, INL hopes to offer this open-source engine to the public. This session will outline the development processes for making Needle™s search interface and simplifying the federation of internal and external data sources.

  16. Three dimensional transducer

    SciTech Connect

    Warren, Oden Lee; Asif, Syed Amanulla Syed; Oh, Yunje; Feng, Yuxin; Cyrankowski, Edward; Major, Ryan

    2014-09-30

    A testing instrument for mechanical testing at nano or micron scale includes a transducer body, and a coupling shaft coupled with a probe tip. A transducer body houses a capacitor. The capacitor includes first and second counter electrodes and a center electrode assembly interposed therebetween. The center electrode assembly is movable with the coupling shaft relative to the first and second counter electrodes, for instance in one or more of dimensions including laterally and normally. The center electrode assembly includes a center plate coupled with the coupling shaft and one or more springs extending from the center plate. Upper and lower plates are coupled with the center plate and cover the center plate and the one or more springs. A shaft support assembly includes one or more support elements coupled along the coupling shaft. The shaft support assembly provides lateral support to the coupling shaft.

  17. Nano-optomechanical transducer

    DOEpatents

    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.

  18. Fine needle aspiration of the thyroid

    MedlinePlus

    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 ...

  19. Fine needle aspiration of the thyroid

    MedlinePlus

    Thyroid nodule fine needle aspirate biopsy; Biopsy - thyroid - skinny-needle; Skinny-needle thyroid biopsy ... under your shoulders and your neck extended. The biopsy site is cleaned. A thin needle is inserted ...

  20. Stress wave focusing transducers

    SciTech Connect

    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.

  1. Horizontal geophone transducer assembly

    SciTech Connect

    Hefer, F.W.

    1985-06-25

    The geophone transducer comprises in combination: a geophone capable of detecting horizontal seismic waves, and a rigid casing having a gimbal chamber. A gimbal is provided inside the chamber on which the geophone is mounted for limited free angular movement in one direction only. The gimbal includes in one preferred embodiment a viscous liquid in which the geophone is only partially submerged while it is supported by a U-shaped bracket which is mounted for rotation about a fixed axis.

  2. Polymer film composite transducer

    DOEpatents

    Owen, Thomas E.

    2005-09-20

    A composite piezoelectric transducer, whose piezoeletric element is a "ribbon wound" film of piezolectric material. As the film is excited, it expands and contracts, which results in expansion and contraction of the diameter of the entire ribbon winding. This is accompanied by expansion and contraction of the thickness of the ribbon winding, such that the sound radiating plate may be placed on the side of the winding.

  3. Fluid force transducer

    DOEpatents

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  4. Real-time 3D curved needle segmentation using combined B-mode and power Doppler ultrasound.

    PubMed

    Greer, Joseph D; Adebar, Troy K; Hwang, Gloria L; Okamura, Allison M

    2014-01-01

    This paper presents a real-time segmentation method for curved needles in biological tissue based on analysis of B-mode and power Doppler images from a tracked 2D ultrasound transducer. Mechanical vibration induced by an external voice coil results in a Doppler response along the needle shaft, which is centered around the needle section in the ultrasound image. First, B-mode image analysis is performed within regions of interest indicated by the Doppler response to create a segmentation of the needle section in the ultrasound image. Next, each needle section is decomposed into a sequence of points and transformed into a global coordinate system using the tracked transducer pose. Finally, the 3D shape is reconstructed from these points. The results of this method differ from manual segmentation by 0.71 ± 0.55 mm in needle tip location and 0.38 ± 0.27 mm along the needle shaft. This method is also fast, taking 5-10 ms to run on a standard PC, and is particularly advantageous in robotic needle steering, which involves thin, curved needles with poor echogenicity. PMID:25485402

  5. Benchmarking of state-of-the-art needle detection algorithms in 3D ultrasound data volumes

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; de With, Peter H. N.; Korsten, Hendrikus H. M.; Mihajlovic, Nenad

    2015-03-01

    Ultrasound-guided needle interventions are widely practiced in medical diagnostics and therapy, i.e. for biopsy guidance, regional anesthesia or for brachytherapy. Needle guidance using 2D ultrasound can be very challenging due to the poor needle visibility and the limited field of view. Since 3D ultrasound transducers are becoming more widely used, needle guidance can be improved and simplified with appropriate computer-aided analyses. In this paper, we compare two state-of-the-art 3D needle detection techniques: a technique based on line filtering from literature and a system employing Gabor transformation. Both algorithms utilize supervised classification to pre-select candidate needle voxels in the volume and then fit a model of the needle on the selected voxels. The major differences between the two approaches are in extracting the feature vectors for classification and selecting the criterion for fitting. We evaluate the performance of the two techniques using manually-annotated ground truth in several ex-vivo situations of different complexities, containing three different needle types with various insertion angles. This extensive evaluation provides better understanding on the limitations and advantages of each technique under different acquisition conditions, which is leading to the development of improved techniques for more reliable and accurate localization. Benchmarking results that the Gabor features are better capable of distinguishing the needle voxels in all datasets. Moreover, it is shown that the complete processing chain of the Gabor-based method outperforms the line filtering in accuracy and stability of the detection results.

  6. A circular array transducer for photoacoustic imaging by using piezoelectric single crystal lead magnesium niobate-lead zirconate titanate

    NASA Astrophysics Data System (ADS)

    Cao, Yonggang; Ha, Kanglyeol; Kim, Moojoon; Kang, Hyunwook; Oh, Jung-Hwan; Kim, Jungsoon

    2015-07-01

    The ultrasound transducers of which center frequencies are lower than 10 MHz are commonly used in low frequency photoacoustic (PA) imaging systems. However, the improvement of their sensitivity is still needed to detect weak PA signals. In this study, a circular array transducer was constructed by using 120 needle hydrophones made of piezoelectric single crystal lead magnesium niobate-lead zirconate titanate (PMN-PZT). The needle hydrophone was designed to have high sensitivity and wide bandwidth through the Krimtholz-Leedom-Matthaei (KLM) simulation of receiving impulse response. The sensitivity of the fabricated PMN-PZT hydrophone was compared with a commercial poly(vinylidene fluoride) (PVDF) needle hydrophone. The usefulness of the circular array transducer was demonstrated by applying it to a PA system for obtaining images.

  7. Transducers for ultrasonic limb plethysmography

    NASA Technical Reports Server (NTRS)

    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. An electromechanical displacement transducer

    NASA Astrophysics Data System (ADS)

    Villiers, Marius; Mahboob, Imran; Nishiguchi, Katsuhiko; Hatanaka, Daiki; Fujiwara, Akira; Yamaguchi, Hiroshi

    2016-08-01

    Two modes of an electromechanical resonator are coupled through the strain inside the structure with a cooperativity as high as 107, a state-of-the-art value for purely mechanical systems, which enables the observation of normal-mode splitting. This coupling is exploited to transduce the resonator’s fundamental mode into the bandwidth of the second flexural mode, which is 1.4 MHz higher in frequency. Thus, an all-mechanical heterodyne detection scheme is implemented that can be developed into a high-precision displacement sensor.

  9. Improved Micromachined Transducers

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.; Wise, James H.

    1994-01-01

    Sensor systems of proposed type incorporate micromachined silicon-based structures as electrostatic force and displacement actuators and micromachined quantum-mechanical-tunneling electrodes as one form of displacement transducers, along with electronic circuits providing multiple electrical stimuli to displacement electrodes for measurement, calibration, monitoring of sensor status, and adjustment. Concept applicable to accelerometers, seismometers, geophones, magnetometers, pressure gauges, and other sensors in which phenomena of interest measured in terms of forces on, and/or displacements of, structural components. Provides completely remote measurement, control, health monitoring, treatment, and like, using telemetry commands.

  10. Thin film strain transducer

    NASA Technical Reports Server (NTRS)

    Rand, J. L. (Inventor)

    1984-01-01

    A strain transducer system and process for making the same is disclosed. A beryllium copper ring having four strain gages is electrically connected in Wheatstone bridge fashion to the output instrumentation. Tabs are bonded to a balloon or like surface with strain on the surface causing bending of a ring which provides an electrical signal through the gages proportional to the surface strain. A photographic pattern of a one half ring segment as placed on a sheet of beryllium copper for chem-mill etch formation is illustrated.

  11. Wellbore pressure transducer

    DOEpatents

    Shuck, Lowell Z.

    1979-01-01

    Subterranean earth formations containing energy values are subjected to hydraulic fracturing procedures to enhance the recovery of the energy values. These fractures are induced in the earth formation by pumping liquid into the wellbore penetrating the earth formation until the pressure of the liquid is sufficient to fracture the earth formation adjacent to the wellbore. The present invention is directed to a transducer which is positionable within the wellbore to generate a signal indicative of the fracture initiation useful for providing a timing signal to equipment for seismic mapping of the fracture as it occurs and for providing a measurement of the pressure at which the fracture is initiated.

  12. RADIO-ACTIVE TRANSDUCER

    DOEpatents

    Wanetick, S.

    1962-03-01

    ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

  13. Transducer of linear displacements

    NASA Astrophysics Data System (ADS)

    Malamed, Y. R.

    1984-02-01

    The basic PLP transducer is designed for a UIM-29 microscope and a 2-coordinate measuring instrument with electronic digital readout. Its optical system consists of an AL-107B light-emitting diode as light source, two condenser lenses, a special wedge carrying two pairs of joined receiver lenses, a prism-mirror, a photoreceiver, a wedge-shape transparent replica of a twin diffraction grating which prevents light reflected by the air-glass interface from focusing on the receiver photodiodes, and a reflective replica of a diffraction grating on a movable carriage. The already available three models of this transducer are PLP1-0.2, PLP1-0.5, and PLP1-1.0 with respectively 625, 250, 125 lines/mm on the transparent replica and respectively 312.5, 125, 62.5 lines/mm on the reflective replica. The scale of moire-interference fringes characterizing the shift between both diffraction gratings per grating period (9.16 mm in each model) is respectively 0.8, 2.0, 4.0 microns and the angle between the two arrays of grating lines on the transparent replica is respectively 36 + or - 4 deg, 90 + or - 10 deg, 190 + or - 20 deg.

  14. Improved Piezoelectric Loudspeakers And Transducers

    NASA Technical Reports Server (NTRS)

    Regan, Curtis Randall; Jalink, Antony; Hellbaum, Richard F.; Rohrbach, Wayne W.

    1995-01-01

    Loudspeakers and related acoustic transducers of improved type feature both light weight and energy efficiency of piezoelectric transducers and mechanical coupling efficiency. Active component of transducer made from wafer of "rainbow" piezoelectric material, ceramic piezoelectric material chemically reduced on one face. Chemical treatment forms wafer into dishlike shallow section of sphere. Both faces then coated with electrically conductive surface layers serving as electrodes. Applications include high-fidelity loudspeakers, and underwater echo ranging devices.

  15. Ultrasonic Transducers for Fourier Analysis.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1995-01-01

    Describes an experiment that uses the ultrasonic transducer for demonstrating the Fourier components of waveshapes such as the square and triangular waves produced by laboratory function generators. (JRH)

  16. Miniature multimode monolithic flextensional transducers.

    PubMed

    Hladky-Hennion, Anne-Christine; Uzgur, A Erman; Markley, Douglas C; Safari, Ahmad; Cochran, Joe K; Newnham, Robert E

    2007-10-01

    Traditional flextensional transducers classified in seven groups based on their designs have been used extensively in 1-100 kHz range for mine hunting, fish finding, oil explorations, and biomedical applications. In this study, a new family of small, low cost underwater, and biomedical transducers has been developed. After the fabrication of transducers, finite-elements analysis (FEA) was used extensively in order to optimize these miniature versions of high-power, low-frequency flextensional transducer designs to achieve broad bandwidth for both transmitting and receiving, engineered vibration modes, and optimized acoustic directivity patterns. Transducer topologies with various shapes, cross sections, and symmetries can be fabricated through high-volume, low-cost ceramic and metal extrusion processes. Miniaturized transducers posses resonance frequencies in the range of above 1 MHz to below 10 kHz. Symmetry and design of the transducer, polling patterns, driving and receiving electrode geometries, and driving conditions have a strong effect on the vibration modes, resonance frequencies, and radiation patterns. This paper is devoted to small, multimode flextensional transducers with active shells, which combine the advantages of small size and low-cost manufacturing with control of the shape of the acoustic radiation/receive pattern. The performance of the transducers is emphasized. PMID:18019236

  17. System for calibrating pressure transducer

    NASA Technical Reports Server (NTRS)

    Rollins, G. N. (Inventor)

    1973-01-01

    A system for calibrating a pressure transducer which has a reference portion and an active portion is reported. A miniature selector valve is positioned immediately adjacent the pressure transducer. A reference pressure, known pressure, and unknown pressure can be selectively admitted to the active side of the pressure transducer by the selector valve to enable calibration of the transducer. A valve admits pressure to the selector valve which has a piston and floating piston arrangement which allows proper selection with very small linear movement.

  18. Electromagnetic acoustic transducer

    DOEpatents

    Alers, George A.; Burns, Jr., Leigh R.; MacLauchlan, Daniel T.

    1988-01-01

    A noncontact ultrasonic transducer for studying the acoustic properties of a metal workpiece includes a generally planar magnetizing coil positioned above the surface of the workpiece, and a generally planar eddy current coil between the magnetizing coil and the workpiece. When a large current is passed through the magnetizing coil, a large magnetic field is applied to the near-surface regions of the workpiece. The eddy current coil can then be operated as a transmitter by passing an alternating current therethrough to excite ultrasonic waves in the surface of the workpiece, or operated as a passive receiver to sense ultrasonic waves in the surface by measuring the output signal. The geometries of the two coils can be varied widely to be effective for different types of ultrasonic waves. The coils are preferably packaged in a housing which does not interfere with their operation, but protects them from a variety of adverse environmental conditions.

  19. Optically transduced MEMS magnetometer

    SciTech Connect

    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.

  20. An opening electromagnetic transducer

    NASA Astrophysics Data System (ADS)

    Sun, Yanhua; Kang, Yihua

    2013-12-01

    Tubular solenoids have been widely used without any change since an electrical wire was discovered to create magnetic fields by Hans Christian Oersted in 1820 and thereby the wire was first coiled as a helix into a solenoid coil by William Sturgeon in 1823 and was improved by Joseph Henry in 1829 [see http://www.myetymology.com/encyclopedia/History_of_the_electricity.html; J. M. D. Coey, Magnetism and Magnetic Materials (Cambridge University Press, New York, 2010); and F. Winterberg, Plasma Phys. 8, 541553 (1996)]. A magnetic control method of C-shaped carrying-current wire is proposed, and thereby a new opening electromagnetic transducer evidently differing from the traditional tubular solenoid is created, capable of directly encircling and centering the acted objects in it, bringing about convenient and innovative electromagnetic energy conversion for electromagnetic heating, electromagnetic excitation, physical information capture, and electro-mechanical motion used in science research, industry, and even biomedical activities.

  1. Adjustable holder for transducer mounting

    NASA Technical Reports Server (NTRS)

    Deotsch, R. C.

    1980-01-01

    Positioning of acoustic sensor, strain gage, or similar transducer is facilitated by adjustable holder. Developed for installation on Space Shuttle, it includes springs for maintaining uniform load on transducer with adjustable threaded cap for precisely controlling position of sensor with respect to surrounding structure.

  2. Needle bar for warp knitting machines

    DOEpatents

    Hagel, Adolf; Thumling, Manfred

    1979-01-01

    Needle bar for warp knitting machines with a number of needles individually set into slits of the bar and having shafts cranked to such an extent that the head section of each needle is in alignment with the shaft section accommodated by the slit. Slackening of the needles will thus not influence the needle spacing.

  3. Circuit for Driving Piezoelectric Transducers

    NASA Technical Reports Server (NTRS)

    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

  4. Micromachined silicon seismic transducers

    SciTech Connect

    Barron, C.C.; Fleming, J.G.; Sniegowski, J.J.; Armour, D.L.; Fleming, R.P.

    1995-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of CTBT monitoring by providing inexpensive, easily depolyable sensor arrays. Although our goal is to fabricate seismic sensors that provide the same performance level as the current state-of-the-art ``macro`` systems, if necessary one could deploy a larger number of these small sensors at closer proximity to the location being monitored in order to compensate for lower performance. We have chosen a modified pendulum design and are manufacturing prototypes in two different silicon micromachining fabrication technologies. The first set of prototypes, fabricated in our advanced surface- micromachining technology, are currently being packaged for testing in servo circuits -- we anticipate that these devices, which have masses in the 1--10 {mu}g range, will resolve sub-mG signals. Concurrently, we are developing a novel ``mold`` micromachining technology that promises to make proof masses in the 1--10 mg range possible -- our calculations indicate that devices made in this new technology will resolve down to at least sub-{mu}G signals, and may even approach to 10{sup {minus}10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  5. A needle guidance system for biopsy and therapy using two-dimensional ultrasound

    SciTech Connect

    Bluvol, Nathan; Sheikh, Allison; Kornecki, Anat; Del Rey Fernandez, David; Downey, Donal; Fenster, Aaron

    2008-02-15

    Image-guided needle biopsies are currently used to provide a definitive diagnosis of breast cancer; however, difficulties in tumor targeting exist as the ultrasound (United States) scan plane and biopsy needle must remain coplanar throughout the procedure to display the actual needle tip position. The additional time associated with aligning and maintaining this coplanar relationship results in increased patient discomfort. Biopsy procedural efficiency is further hindered since needle pathway interpretation is often difficult, especially for needle insertions at large depths that usually require multiple reinsertions. The authors developed a system that would increase the speed and accuracy of current breast biopsy procedures using readily available two-dimensional (2D) US technology. This system is composed of a passive articulated mechanical arm that attaches to a 2D US transducer. The arm is connected to a computer through custom electronics and software, which were developed as an interface for tracking the positioning of the mechanical components in real time. The arm couples to the biopsy needle and provides visual guidance for the physician performing the procedure in the form of a real-time projected needle pathway overlay on an US image of the breast. An agar test phantom, with stainless steel targets interspersed randomly throughout, was used to validate needle trajectory positioning accuracy. The biopsy needle was guided by both the software and hardware components to the targets. The phantom, with the needle inserted and device decoupled, was placed in an x-ray stereotactic mammography (SM) machine. The needle trajectory and bead target locations were determined in three dimensions from the SM images. Results indicated a mean needle trajectory accuracy error of 0.75{+-}0.42 mm. This is adequate to sample lesions that are <2 mm in diameter. Chicken tissue test phantoms were used to compare core needle biopsy procedure times between experienced

  6. Passive wireless ultrasonic transducer systems

    NASA Astrophysics Data System (ADS)

    Zhong, C. H.; Croxford, A. J.; Wilcox, P. D.

    2014-02-01

    Inductive coupling and capacitive coupling both offer simple solutions to wirelessly probe ultrasonic transducers. This paper investigates the theory and feasibility of such system in the context of non-destructive evaluation (NDE) applications. Firstly, the physical principles and construction of an inductively coupled transducer system (ICTS) and a capacitively coupled transducer system (CCTS) are introduced. Then the development of a transmission line model with the measured impedance of a bonded piezoelectric ceramic disc representing a sensor attached to an arbitrary solid substrate for both systems is described. The models are validated experimentally. Several applications of CCTS are presented, such CCTS for the underwater and through-composite testing.

  7. Arterial pulse wave pressure transducer

    NASA Technical Reports Server (NTRS)

    Kim, C.; Gorelick, D.; Chen, W. (Inventor)

    1974-01-01

    An arterial pulse wave pressure transducer is introduced. The transducer is comprised of a fluid filled cavity having a flexible membrane disposed over the cavity and adapted to be placed on the skin over an artery. An arterial pulse wave creates pressure pulses in the fluid which are transduced, by a pressure sensitive transistor in direct contact with the fluid, into an electric signal. The electrical signal is representative of the pulse waves and can be recorded so as to monitor changes in the elasticity of the arterial walls.

  8. Feasibility of Rotational Scan Ultrasound Imaging by an Angled High Frequency Transducer for the Posterior Segment of the Eye

    PubMed Central

    Paeng, Dong-Guk; Chang, Jin Ho; Chen, Ruimin; Humayun, Mark S.; Shung, K. Kirk

    2009-01-01

    High frequency ultrasound over 40 MHz has been used to image the anterior segment of the eye, but it is not suitable for the posterior segment due to the frequency-dependent attenuation of ultrasound and thus the limitation of penetration depth. This paper proposes a novel scan method to image the posterior segment of the eye with an angled high frequency (beyond 40 MHz) ultrasound needle transducer. In this method, the needle transducer is inserted into the eye through a small incision hole (∼1 mm in diameter) and rotated around the axial direction to form a cone-shaped imaging plane, allowing the spatial information of retinal vessels and diagnosis of their occlusion to be displayed. The feasibility of this novel technique was tested with images of a wire phantom, a polyimide tube, and an excised pig eye obtained by manually rotating a 40-MHz PMN-PT needle transducer with a beveled tip of 45°. From the results, we believe that rotational scan imaging will help expand the minimally invasive applications of high frequency ultrasound to other areas due to the capability of increased closeness of an angled needle transducer to structures of interest buried in other tissues. PMID:19411226

  9. Needle Thoracotomy in Trauma.

    PubMed

    Rottenstreich, Misgav; Fay, Shmuel; Gendler, Sami; Klein, Yoram; Arkovitz, Marc; Rottenstreich, Amihai

    2015-12-01

    Tension pneumothorax is one of the leading causes of preventable death in trauma patients. Needle thoracotomy (NT) is the currently accepted first-line intervention but has not been well validated. In this review, we have critically discussed the evidence for NT procedure, re-examined the recommendations by the Advanced Trauma Life Support organization and investigated the safest and most effective way of NT. The current evidence to support the use of NT is limited. However, when used, it should be applied in the 2nd intercostal space at midclavicular line using a catheter length of at least 4.5 cm. Alternative measures should be studied for better prehospital management of tension pneumothorax. PMID:26633663

  10. Fixture for holding testing transducer

    DOEpatents

    Wagner, T.A.; Engel, H.P.

    A fixture for mounting an ultrasonic transducer against the end of a threaded bolt or stud to test the same for flaws. A base means threadedly secured to the side of the bolt has a rotating ring thereon. A post rising up from the ring (parallel to the axis of the workpiece) pivotally mounts a variable length cross arm, on the inner end of which is mounted the transducer. A spring means acts between the cross arm and the base to apply the testing transducer against the workpiece at a constant pressure. The device maintains constant for successive tests the radial and circumferential positions of the testing transducer and its contact pressure against the end of the workpiece.

  11. Fixture for holding testing transducer

    DOEpatents

    Wagner, Thomas A.; Engel, Herbert P.

    1984-01-01

    A fixture for mounting an ultrasonic transducer against the end of a threaded bolt or stud to test the same for flaws. A base means threadedly secured to the side of the bolt has a rotating ring thereon. A post rising up from the ring (parallel to the axis of the workpiece) pivotally mounts a variable length cross arm, on the inner end of which is mounted the transducer. A spring means acts between the cross arm and the base to apply the testing transducer against the workpiece at a constant pressure. The device maintains constant for successive tests the radial and circumferential positions of the testing transducer and its contact pressure against the end of the workpiece.

  12. An enzyme logic bioprotonic transducer

    SciTech Connect

    Miyake, Takeo; Keene, Scott; Deng, Yingxin; Rolandi, Marco; Josberger, Erik E.

    2015-01-01

    Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdH{sub x} electrode as a bioprotonic transducer that connects H{sup +} currents in solution into an electronic signal. This transducer exploits the reversible formation of PdH{sub x} in solution according to PdH↔Pd + H{sup +} + e{sup −}, and the dependence of this formation on solution pH and applied potential. We integrate the protonic transducer with glucose dehydrogenase as an enzymatic AND gate for glucose and NAD{sup +}. PdH{sub x} formation and associated electronic current monitors the output drop in pH, thus transducing a biological function into a measurable electronic output.

  13. An enzyme logic bioprotonic transducer

    NASA Astrophysics Data System (ADS)

    Miyake, Takeo; Josberger, Erik E.; Keene, Scott; Deng, Yingxin; Rolandi, Marco

    2015-01-01

    Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdHx electrode as a bioprotonic transducer that connects H+ currents in solution into an electronic signal. This transducer exploits the reversible formation of PdHx in solution according to PdH↔Pd + H+ + e-, and the dependence of this formation on solution pH and applied potential. We integrate the protonic transducer with glucose dehydrogenase as an enzymatic and gate for glucose and NAD+. PdHx formation and associated electronic current monitors the output drop in pH, thus transducing a biological function into a measurable electronic output.

  14. Acoustic transducer with damping means

    DOEpatents

    Smith, Richard W.; Adamson, Gerald E.

    1976-11-02

    An ultrasonic transducer specifically suited to high temperature sodium applications is described. A piezoelectric active element is joined to the transducer faceplate by coating the faceplate and juxtaposed active element face with wetting agents specifically compatible with the bonding procedure employed to achieve the joint. The opposite face of the active element is fitted with a backing member designed to assure continued electrical continuity during adverse operating conditions which can result in the fracturing of the active element. The fit is achieved employing a spring-loaded electrode operably arranged to electrically couple the internal transducer components, enclosed in a hermetically sealed housing, to accessory components normally employed in transducer applications. Two alternative backing members are taught for assuring electrical continuity. The first employs a resilient, discrete multipoint contact electrode in electrical communication with the active element face. The second employs a resilient, elastomeric, electrically conductive, damped member in electrical communication with the active element face in a manner to effect ring-down of the transducer. Each embodiment provides continued electrical continuity within the transducer in the event the active element fractures, while the second provides the added benefit of damping.

  15. Integrated transducer for color distinction

    NASA Astrophysics Data System (ADS)

    Kato, Hisao; Kojima, Masahiko; Yoshida, Akira

    1983-06-01

    A method for fabricating the improved version of an integrated transducer for color distinction is proposed. It consists of three SnO2(n)-Si(n) photodiodes on a Si wafer and a trichromatic filter prepared by arranging filters of the three primary colors (Eastman Kodak gelatin filters; Nos. 47B, 58, and 25) on an infrared glass filter (Hoya Glass; B-460). Its photoelectric characteristics and dependence of error of color distinction on the dimension of the transducer are reported. The photodiodes employed in this conversion assembly are produced by the simple spray method and are most suitable for detecting the low illumination. Since this transducer adapts the trichromatic color resolution method, highly accurate color distinction is possible. With this type of transducer, three photodiodes sensitive to the primary colors, red, green, and blue, respectively, are arranged on a plane. An error in color distinction can occur due to the differences in the strength of the light incident upon the respective photodiodes. This problem is reduced by making the transducer more compact. Finally, 11 kinds of colors are discerned in this experiment as an application of the transducer.

  16. Ultrasonic Transducer Irradiation Test Results

    SciTech Connect

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Kohse, Gordon; Tittmann, Bernhard; Reinhardt, Brian; Rempe, Joy

    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

  17. Auto-positioning ultrasonic transducer system

    NASA Technical Reports Server (NTRS)

    Buchanan, Randy K. (Inventor)

    2010-01-01

    An ultrasonic transducer apparatus and process for determining the optimal transducer position for flow measurement along a conduit outer surface. The apparatus includes a transmitting transducer for transmitting an ultrasonic signal, said transducer affixed to a conduit outer surface; a guide rail attached to a receiving transducer for guiding movement of a receiving transducer along the conduit outer surface, wherein the receiving transducer receives an ultrasonic signal from the transmitting transducer and sends a signal to a data acquisition system; and a motor for moving the receiving transducer along the guide rail, wherein the motor is controlled by a controller. The method includes affixing a transmitting transducer to an outer surface of a conduit; moving a receiving transducer on the conduit outer surface, wherein the receiving transducer is moved along a guide rail by a motor; transmitting an ultrasonic signal from the transmitting transducer that is received by the receiving transducer; communicating the signal received by the receiving transducer to a data acquisition and control system; and repeating the moving, transmitting, and communicating along a length of the conduit.

  18. Fabrication of tungsten wire needles

    SciTech Connect

    Roder, A.

    1983-02-01

    Fine point needles for field emissoin are conventionally produced by electrolytically or chemically etching tungsten wire. Points formed in this manner have a typical tip radius of about 0.5 microns and a cone angle of some 30 degrees. The construction of needle matrix detector chambers has created a need for tungsten needles whose specifications are: 20 mil tungsten wire, 1.5 inch total length, 3 mm-long taper (resulting in a cone angle of about 5 degrees), and 25 micron-radius point (similar to that found on sewing needles). In the process described here for producing such needles, tungsten wire, immersed in a NaOH solution and in the presence of an electrode, is connected first to an ac voltage and then to a dc supply, to form a taper and a point on the end of the wire immersed in the solution. The process parameters described here are for needles that will meet the above specifications. Possible variations will be discussed under each approprite heading.

  19. 3D transrectal ultrasound prostate biopsy using a mechanical imaging and needle-guidance system

    NASA Astrophysics Data System (ADS)

    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.

  20. Model of a Piezoelectric Transducer

    NASA Technical Reports Server (NTRS)

    Goodenow, Debra

    2004-01-01

    It's difficult to control liquid and gas in propellant tanks in zero gravity. A possible a design would utilize acoustic liquid manipulation (ALM) technology which uses ultrasonic beams conducted through a liquid and solid media, to push gas bubbles in the liquid to desirable locations. We can propel and control the bubble with acoustic radiation pressure by aiming the acoustic waves on the bubble s surface. This allows us to design a so called smart tank in which the ALM devices transfer the gas to the outer wall of the tank and isolating the liquid in the center. Because the heat transfer rate of a gas is lower of that of the liquid it would substantially decrease boil off and provide of for a longer storage life. The ALM beam is composed of little wavelets which are individual waves that constructively interfere with each other to produce a single, combined acoustic wave front. This is accomplished by using a set of synchronized ultrasound transducers arranged in an array. A slight phase offset of these elements allows us to focus and steer the beam. The device that we are using to produce the acoustic beam is called the piezoelectric transducer. This device converts electrical energy to mechanical energy, which appears in the form of acoustic energy. Therefore the behavior of the device is dependent on both the mechanical characteristics, such as its density, cross-sectional area, and its electrical characteristics, such as, electric flux permittivity and coupling factor. These devices can also be set up in a number of modes which are determined by the way the piezoelectric device is arranged, and the shape of the transducer. For this application we are using the longitudinal or thickness mode for our operation. The transducer also vibrates in the lateral mode, and one of the goals of my project is to decrease the amount of energy lost to the lateral mode. To model the behavior of the transducers I will be using Pspice, electric circuit modeling tool, to

  1. Rugged Direct-Current Transducer

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1991-01-01

    Direct-current transducer withstands thermal and mechanical shocks. Operates from single, nominally 15-V power supply and nearly insensitive to both large variations in temperature and variations of as much as plus or minus 5 V in supply voltage. Its output voltage highly linear function of sensed current, with full-scale value of about 3 Vdc and offset of about 0.1 Vdc at 0 sensed current. Ruggedness of transducer due in large part to novel magnetic core, machined from solid block of nickel/iron high-permeability, low-hysteresis alloy.

  2. Environmental control system transducer development study

    NASA Technical Reports Server (NTRS)

    Brudnicki, M. J.

    1973-01-01

    A failure evaluation of the transducers used in the environmental control systems of the Apollo command service module, lunar module, and portable life support system is presented in matrix form for several generic categories of transducers to enable identification of chronic failure modes. Transducer vendors were contacted and asked to supply detailed information. The evaluation data generated for each category of transducer were compiled and published in failure design evaluation reports. The evaluation reports also present a review of the failure and design data for the transducers and suggest both design criteria to improve reliability of the transducers and, where necessary, design concepts for required redesign of the transducers. Remedial designs were implemented on a family of pressure transducers and on the oxygen flow transducer. The design concepts were subjected to analysis, breadboard fabrication, and verification testing.

  3. Programmable and automatic calibrator for radio sources at 45 MHz

    NASA Astrophysics Data System (ADS)

    Aparici, J.; May, J.; Salas, F.; Ventura, J.

    1981-12-01

    The design, construction and operation of a standard calibrator is presented. The calibrator consists of saturated diodes controlled by an indirect feed-back system and a digital-to-analog converter. The advantages over similar designs are described, as for instance, high-resolution in the calibration scale, good stability, very fast calibrations, use of balanced electronic switches, etc.

  4. Multi sensor transducer and weight factor

    NASA Technical Reports Server (NTRS)

    Immer, Christopher D. (Inventor); Lane, John (Inventor); Eckhoff, Anthony J. (Inventor); Perotti, Jose M. (Inventor)

    2004-01-01

    A multi-sensor transducer and processing method allow insitu monitoring of the senor accuracy and transducer `health`. In one embodiment, the transducer has multiple sensors to provide corresponding output signals in response to a stimulus, such as pressure. A processor applies individual weight factors to reach of the output signals and provide a single transducer output that reduces the contribution from inaccurate sensors. The weight factors can be updated and stored. The processor can use the weight factors to provide a `health` of the transducer based upon the number of accurate versus in-accurate sensors in the transducer.

  5. Remote electrically passive position transducer

    NASA Astrophysics Data System (ADS)

    Ducharme, Alfred D.; Markos, Constantine T.; Rieder, R. J.; Wijntjes, Geert J.

    1999-02-01

    We will report on the design and testing of a precision, remote, via fiber optics position transducer suitable for incorporation in a closed loop fly-by-light positioning system. The design is based on Visidyne developed technology for an ultra high resolution optical radar based on Continuous Wave modulated light at a frequency of 1 GHz. It produces digital position data with 12 bit precision e.g., for a travel distance, stroke of 6 inches or greater at a bandwidth, update rate of 1 KHz. The passive nature of the transducer at the actuator location and the high operating frequency makes it highly tolerant to even extreme levels of Electro Magnetic Interference and when constructed from high temperature material is can operate at temperatures well in excess of 300 degrees C. We will discuss transducer performance, precision and position stability with particular emphasis on the effects of length changes within the multi-mode optical fibers used to deliver and collect the light to and from the transducer. We will also discuss cost aspects of the design and their effect on overcoming market entry barriers.

  6. Dynamic Calibration of Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Hess, R. W.; Davis, W. T.; Davis, P. A.

    1985-01-01

    Sinusoidal calibration signal produced in 4- to 100-Hz range. Portable oscillating-pressure device measures dynamic characteristics of pressure transducers installed in models or aircraft at frequency and oscillating-pressure ranges encountered during unsteady-pressure-measurement tests. Calibration is over range of frequencies and amplitudes not available with commercial acoustic calibration devices.

  7. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  8. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  9. Non-bonded ultrasonic transducer

    DOEpatents

    Eoff, J.M.

    1984-07-06

    A mechanically assembled non-bonded ultrasonic transducer includes a substrate, a piezoelectric film, a wetting agent, a thin metal electrode, and a lens held in intimate contact by a mechanical clamp. No epoxy or glue is used in the assembly of this device.

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

    NASA Astrophysics Data System (ADS)

    Peng, J.; Lau, S. T.; Chao, C.; Dai, J. Y.; Chan, H. L. W.; Luo, H. S.; Zhu, B. P.; Zhou, Q. F.; Shung, K. K.

    2010-01-01

    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 t ) and high piezoelectric constant ( d 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.

  11. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    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.

  12. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

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

    2013-12-01

    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 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.

  13. Seismic transducer measures small horizontal displacements

    NASA Technical Reports Server (NTRS)

    Greenwood, T. L.

    1965-01-01

    Pendular seismic transducer mounted on base plate measures small horizontal displacements of structures subjected to vibration where no fixed reference point is available. Enclosure of transducer in transparent plastic case prevents air currents from disturbing the pendulum balance.

  14. Wideband Single Crystal Transducer for Bone Characterization

    NASA Technical Reports Server (NTRS)

    Sahul, Raffi

    2015-01-01

    Phase II objectives: Optimize the Phase I transducer for sensitivity; Test different transmit signals for optimum performance; Demonstrate compatibility with electronics; Confirm additional transducer capabilities over conventional systems by calibrating with other methods.

  15. Automatic calibration system for pressure transducers

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Fifty-channel automatic pressure transducer calibration system increases quantity and accuracy for test evaluation calibration. The pressure transducers are installed in an environmental tests chamber and manifolded to connect them to a pressure balance which is uniform.

  16. Needle biopsy of the breast.

    PubMed

    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

  17. Does Needle Rotation Improve Lesion Targeting?

    PubMed Central

    Badaan, Shadi; Petrisor, Doru; Kim, Chunwoo; Mozer, Pierre; Mazilu, Dumitru; Gruionu, Lucian; Patriciu, Alex; Cleary, Kevin; Stoianovici, Dan

    2011-01-01

    Background Image-guided robots are manipulators that operate based on medical images. Perhaps the most common class of image-guided robots are robots for needle interventions. Typically, these robots actively position and/or orient a needle guide, but needle insertion is still done by the physician. While this arrangement may have safety advantages and keep the physician in control of needle insertion, actuated needle drivers can incorporate other useful features. Methods We first present a new needle driver that can actively insert and rotate a needle. With this device we investigate the use of needle rotation in controlled in-vitro experiments performed with a specially developed revolving needle driver. Results These experiments show that needle rotation can improve targeting and may reduce errors by as much as 70%. Conclusion The new needle driver provides a unique kinematic architecture that enables insertion with a compact mechanism. Perhaps the most interesting conclusion of the study is that lesions of soft tissue organs may not be perfectly targeted with a needle without using special techniques, either manually or with a robotic device. The results of this study show that needle rotation may be an effective method of reducing targeting errors. PMID:21360796

  18. Magnetic needles and superparamagnetic cells

    PubMed Central

    Bryant, H C; Sergatskov, D A; Lovato, Debbie; Adolphi, Natalie L; Larson, Richard S; Flynn, Edward R

    2007-01-01

    Superparamagnetic nanoparticles can be attached in great numbers to pathogenic cells using specific antibodies so that the magnetically-labeled cells themselves become superparamagnets. The cells can then be manipulated and drawn out of biological fluids, as in a biopsy, very selectively using a magnetic needle. We examine the origins and uncertainties in the forces exerted on magnetic nanoparticles by static magnetic fields, leading to a model for trajectories and collection times of dilute superparamagnetic cells in biological fluids. We discuss the design and application of such magnetic needles and the theory of collection times. We compare the mathematical model to measurements in a variety of media including blood. PMID:17664592

  19. Magnetometer with miniature transducer and automatic transducer scanning apparatus

    NASA Technical Reports Server (NTRS)

    Breckenridge, R. A.; Debnam, W. J., Jr.; Fales, C. L.; Pohm, A. V.

    1974-01-01

    Magnetometer is simple to operate and has fast response. Transducer is rugged and flat and can measure magnetic fields as close as 0.08 mm from any relatively flat surface. Magnetometer has active region of approximately 0.64 by 0.76 mm and is capable of good spatial resolution of magnetic fields as low as 0.02 Oe (1.6 A/m).

  20. Low-Stress Sealing of Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Kroy, R. E.

    1985-01-01

    Compliant washer seals high pressures without excessive compressive stress on transducer. Conformal washer serves as effective seal for transducer passing through walls of pressure vessel. Washer makes it unnecessary to tighten mounting nut to high torque, which could damage transducer or adversely affect accuracy. Washer also used to seal mountings for temperature sensors and other devices.

  1. Measuring Thicknesses With In Situ Ultrasonic Transducers

    NASA Technical Reports Server (NTRS)

    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.

  2. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to the skin to transmit and...

  3. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to the skin to transmit and...

  4. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to the skin to transmit and...

  5. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to the skin to transmit and...

  6. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to the skin to transmit and...

  7. Secure Container For Discarded Hypodermic Needles

    NASA Technical Reports Server (NTRS)

    Lee, Angelene M.

    1992-01-01

    Container designed for safe retention of discarded blood-collecting hypodermic needles and similar sharp objects used in life-science experiments aboard spacecraft. Needles inserted through self-closing lid and retained magnetically. They are inserted, sharp end first, through spring-loaded flap. Long needles and needles on syringes cannot turn around in container. Can be emptied, cleaned, and reused. Used on Earth to provide unusually secure containment of sharp objects.

  8. Advanced Geothermal Optical Transducer (AGOT)

    SciTech Connect

    2004-09-01

    Today's geothermal pressure-temperature measuring tools are short endurance, high value instruments, used sparingly because their loss is a major expense. In this project LEL offered to build and test a rugged, affordable, downhole sensor capable ofretuming an uninterrupted data stream at pressures and of 10,000 psi and temperatures up to 250 C, thus permitting continuous deep-well logging. It was proposed to meet the need by specializing LEL's patented 'Twin Column Transducer' technology to satisfy the demands of geothermal pressure/temperature measurements. TCT transducers have very few parts, none of which are moving parts, and all of which can be fabricated from high-temperature super alloys or from ceramics; the result is an extremely rugged device, essentially impervious to chemical attack and readily modified to operate at high pressure and temperature. To measure pressure and temperature they capitalize on the relative expansion of optical elements subjected to thermal or mechanical stresses; if one element is maintained at a reference pressure while the other is opened to ambient, the differential displacement then serves as a measure of pressure. A transducer responding to temperature rather than pressure is neatly created by 'inverting' the pressure-measuring design so that both deflecting structures see identical temperatures and temperature gradients, but whose thermal expansion coefficients are deliberately mismatched to give differential expansion. The starting point for development of a PT Tool was the company's model DPT feedback-stabilized 5,000 psi sensor (U.S. Patent 5,311,014, 'Optical Transducer for Measuring Downhole Pressure', claiming a pressure transducer capable of measuring static, dynamic, and true bi-directional differential pressure at high temperatures), shown in the upper portion of Figure 1. The DPT occupies a 1 x 2 x 4-inch volume, weighs 14 ounces, and is accurate to 1 percent of full scale. Employing a pair of identical, low

  9. Self-Calibrating Pressure Transducer

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor)

    2006-01-01

    A self-calibrating pressure transducer is disclosed. The device uses an embedded zirconia membrane which pumps a determined quantity of oxygen into the device. The associated pressure can be determined, and thus, the transducer pressure readings can be calibrated. The zirconia membrane obtains oxygen .from the surrounding environment when possible. Otherwise, an oxygen reservoir or other source is utilized. In another embodiment, a reversible fuel cell assembly is used to pump oxygen and hydrogen into the system. Since a known amount of gas is pumped across the cell, the pressure produced can be determined, and thus, the device can be calibrated. An isolation valve system is used to allow the device to be calibrated in situ. Calibration is optionally automated so that calibration can be continuously monitored. The device is preferably a fully integrated MEMS device. Since the device can be calibrated without removing it from the process, reductions in costs and down time are realized.

  10. Characterizing tissue stiffness at the tip of a rigid needle using an opto-mechanical force sensor (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Beekmans, Steven V.; Iannuzzi, Davide; van den Dobbelsteen, John J.

    2016-03-01

    Each year, in the Netherlands alone, more than 50.000 percutaneous procedures are performed for treatment or for removal of tissue from possibly diseased organs, of which 30% return non-diagnostic due to erroneous needle targeting, often as a result of non-homogeneity of the penetrated tissue. In this study, we aim to facilitate needle targeting by assessing the tissue in front of the needle based on its mechanical properties. A probe that can identify tissues via real-time measurements of their mechanical properties is placed at the tip of the needle. The probe, actuated by a remote system at the distal part of the needle, employs the bending of a micro-machined cantilever fabricated on top of an optical fiber. The displacement of the cantilever, imposed by pressing a micro-bead (r = 75 µm) glued at the tip of the cantilever against the tissue, is interrogated by Fabry-Pérot interferometry and converted to force acted on the tissue in real-time. The force transducer is able to perform in harsh environments due to its monolithic design and all-optical working principle. Using our setup, load-indentation curves were obtained during needle insertion in several gelatin-based specimens. We demonstrate the ability of our device to detect and quantify layers of varying stiffness and to successfully locate tissue boundaries in animal tissue embedded in gelatin. Furthermore, a diagnostic measurement can be made by quantifying intra-organ tissue stiffness at the needle target location.

  11. Elongation Transducer For Tensile Tests

    NASA Technical Reports Server (NTRS)

    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.

  12. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... in 21 CFR 801.109, (2) Device material biocompatibility, and (3) Device sterility. ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to...

  13. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... in 21 CFR 801.109, (2) Device material biocompatibility, and (3) Device sterility. ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to...

  14. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... in 21 CFR 801.109, (2) Device material biocompatibility, and (3) Device sterility. ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to...

  15. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... in 21 CFR 801.109, (2) Device material biocompatibility, and (3) Device sterility. ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to...

  16. Split-mode ultrasonic transducer.

    PubMed

    Ostrovskii, Igor; Cremaldi, Lucien

    2013-08-01

    A split-mode ultrasonic transducer is investigated in both theory and experiment. This transducer is a two-dimensional structure of periodically poled domains in a ferroelectric wafer with free surfaces. The acoustic vibrations are excited by a radio frequency electric current applied along the length of the wafer, which allows the basal-plane surfaces to be free of metal coatings and thus ready for further biomedical applications. A specific physical property of this transducer consists of the multiple acousto-electric resonances, which occur due to an acoustic mode split when the acoustic half-wavelength is equal to the domain length. Possible applications include ultrasonic generation and detection at the micro-scale, intravascular sonification and visualization, ultrasound therapy of localized small areas such as the eye, biomedical applications for cell cultures, and traditional nondestructive testing including bones and tissues. A potential use of a non-metallized wafer is a therapeutic application with double action that is both ultrasound itself and an electric field over the wafer. The experimental measurements and theoretical calculations are in good agreement. PMID:23927212

  17. Wideband focused transducer array for optoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Simonova, V. A.; Khokhlova, T. D.; Karabutov, A. A.

    2009-11-01

    The calculation procedure of the parameters of a multielement transducer array for the optoacoustic tomography of biological objects with high spatial resolution values is proposed. A multielement transducer with given spatial resolution values in three dimensions has been developed based on the proposed procedure for the early detection of breast cancer. The transducer array consists of a set of 8 linear PVDF piezoelectric films located on a plane and a focusing cylindrical acoustic lens. A map of the transducer’s focal area and point spread function have been measured using the constructed transducer array. Spatial resolutions of the transducer array obtained experimentally are in agreement with their calculated values.

  18. Acoustic transducer for nuclear reactor monitoring

    DOEpatents

    Ahlgren, Frederic F.; Scott, Paul F.

    1977-01-01

    A transducer to monitor a parameter and produce an acoustic signal from which the monitored parameter can be recovered. The transducer comprises a modified Galton whistle which emits a narrow band acoustic signal having a frequency dependent upon the parameter being monitored, such as the temperature of the cooling media of a nuclear reactor. Multiple locations within a reactor are monitored simultaneously by a remote acoustic receiver by providing a plurality of transducers each designed so that the acoustic signal it emits has a frequency distinct from the frequencies of signals emitted by the other transducers, whereby each signal can be unambiguously related to a particular transducer.

  19. Model-based optimization of ultrasonic transducers.

    PubMed

    Heikkola, Erkki; Laitinen, Mika

    2005-01-01

    Numerical simulation and automated optimization of Langevin-type ultrasonic transducers are investigated. These kind of transducers are standard components in various applications of high-power ultrasonics such as ultrasonic cleaning and chemical processing. Vibration of the transducer is simulated numerically by standard finite element method and the dimensions and shape parameters of a transducer are optimized with respect to different criteria. The novelty value of this work is the combination of the simulation model and the optimization problem by efficient automatic differentiation techniques. The capabilities of this approach are demonstrated with practical test cases in which various aspects of the operation of a transducer are improved. PMID:15474952

  20. TOPICAL REVIEW: Capacitive micromachined ultrasonic transducer arrays for minimally invasive medical ultrasound

    NASA Astrophysics Data System (ADS)

    Chen, Jingkuang

    2010-02-01

    This paper reviews the minimally invasive capacitive micromachined ultrasonic transducer (CMUT) arrays for medical diagnosis and therapy. While piezoelectric transducers dominate today's medical ultrasound market, the capacitive micromachined ultrasonic transducer has recently emerged as a promising alternative which delivers a comparable device performance to its piezoelectric counterparts, is compatible with front-end circuit integration, allows high-density imager integration and is relative easy in miniaturization. Utilizing MEMS technology, the substrate of CMUT arrays can be micromachined into miniature platforms with various geometrical shapes, which include needles, three-dimensional prisms, as well as other flexible-substrate configurations. These arrays are useful for reaching deep inside the tissue or an organ with a minimally invasive approach. Due to the close proximity of the transducers to the target organ/tissue, a higher resolution/accuracy of diagnostic information can be achieved. In addition to pulse-echo and photoacoustic imaging, high-power CMUT devices capable of delivering ultrasounds with a pressure greater than 1.0 MPa have been monolithically integrated with imager CMUTs for image-guided therapy (IGT). Such miniature devices would facilitate diagnostic and therapy interventions not possible with conventional piezoelectric transducers.

  1. Lead-Free Intravascular Ultrasound Transducer Using BZT-50BCT Ceramics

    PubMed Central

    Yan, Xingwei; Lam, Kwok Ho; Li, Xiang; Chen, Ruimin; Ren, Wei; Ren, Xiaobing; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    This paper reports the fabrication and evaluation of a high-frequency ultrasonic transducer based on a new lead-free piezoelectric material for intravascular imaging application. Lead-free 0.5Ba(Zr0.2Ti0.8)O3−0.5(Ba0.7Ca0.3)TiO3 (BZT-50BCT) ceramic with a high dielectric constant (~2800) was employed to develop a high-frequency (~30 MHz) needle-type ultrasonic transducer. With superior piezoelectric performance (piezoelectric coefficient d33 ~ 600 pC/N), the lead-free transducer was found to exhibit a −6-dB bandwidth of 53% with an insertion loss of 18.7 dB. In vitro intravascular ultrasound (IVUS) imaging of a human cadaver coronary artery was performed to demonstrate the potential of the lead-free transducer for biomedical imaging applications. This is the first time that a lead-free transducer has been used for IVUS imaging application. The experimental results suggest that the BZT-50BCT ceramic is a promising lead-free piezoelectric material for high-frequency intravascular imaging applications. PMID:25004492

  2. Lead-free BNT composite film for high-frequency broadband ultrasonic transducer applications.

    PubMed

    Yan, Xingwei; Ji, Hongfen; Lam, Kwok Ho; Chen, Ruimin; Zheng, Fan; Ren, Wei; Zhou, Qifa; Shung, K Kirk

    2013-07-01

    A lead-free Bi0.5Na0.5TiO3 (BNT) piezoelectric composite thick film with a thickness of ~11 μm has been fabricated using a modified sol-gel method. Dielectric constant, remnant polarization, and coercive field of the BNT composite film were found to be 1018, 22.6 μC/cm2, and 76.1 kV/cm, respectively. The film was used to fabricate a high-frequency needle transducer and the performance of the transducer was measured. The transducer without a matching layer exhibits a center frequency of 98 MHz and a -6-dB bandwidth of 86%. A wire phantom image acquired using the transducer shows an axial resolution of 15 ¿m and lateral resolution of 68 μm, respectively. Results from this study suggest that the BNT composite film is a promising lead-free piezoelectric material for high-frequency broadband ultrasonic transducer applications. PMID:25004521

  3. Lead-free intravascular ultrasound transducer using BZT-50BCT ceramics.

    PubMed

    Yan, Xingwei; Lam, Kwok Ho; Li, Xiang; Chen, Ruimin; Ren, Wei; Ren, Xiaobing; Zhou, Qifa; Shung, K Kirk

    2013-06-01

    This paper reports the fabrication and evaluation of a high-frequency ultrasonic transducer based on a new lead-free piezoelectric material for intravascular imaging application. Lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO4(BZT-50BCT) ceramic with a high dielectric constant (~2800) was employed to develop a high-frequency (~30 MHz) needle-type ultrasonic transducer. With superior piezoelectric performance (piezoelectric coefficient d33 ~ 600 pC/N), the lead-free transducer was found to exhibit a -6-dB bandwidth of 53% with an insertion loss of 18.7 dB. In vitro intravascular ultrasound (IVUS) imaging of a human cadaver coronary artery was performed to demonstrate the potential of the lead-free transducer for biomedical imaging applications. This is the first time that a lead-free transducer has been used for IVUS imaging application. The experimental results suggest that the BZT-50BCT ceramic is a promising lead-free piezoelectric material for high-frequency intravascular imaging applications. PMID:25004492

  4. A comparison of needle tip localization accuracy using 2D and 3D trans-rectal ultrasound for high-dose-rate prostate cancer brachytherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Hrinivich, W. Thomas; Hoover, Douglas A.; Surry, Kathleen; Edirisinghe, Chandima; Montreuil, Jacques; D'Souza, David; Fenster, Aaron; Wong, Eugene

    2016-03-01

    Background: High-dose-rate brachytherapy (HDR-BT) is a prostate cancer treatment option involving the insertion of hollow needles into the gland through the perineum to deliver a radioactive source. Conventional needle imaging involves indexing a trans-rectal ultrasound (TRUS) probe in the superior/inferior (S/I) direction, using the axial transducer to produce an image set for organ segmentation. These images have limited resolution in the needle insertion direction (S/I), so the sagittal transducer is used to identify needle tips, requiring a manual registration with the axial view. This registration introduces a source of uncertainty in the final segmentations and subsequent treatment plan. Our lab has developed a device enabling 3D-TRUS guided insertions with high S/I spatial resolution, eliminating the need to align axial and sagittal views. Purpose: To compare HDR-BT needle tip localization accuracy between 2D and 3D-TRUS. Methods: 5 prostate cancer patients underwent conventional 2D TRUS guided HDR-BT, during which 3D images were also acquired for post-operative registration and segmentation. Needle end-length measurements were taken, providing a gold standard for insertion depths. Results: 73 needles were analyzed from all 5 patients. Needle tip position differences between imaging techniques was found to be largest in the S/I direction with mean+/-SD of -2.5+/-4.0 mm. End-length measurements indicated that 3D TRUS provided statistically significantly lower mean+/-SD insertion depth error of -0.2+/-3.4 mm versus 2.3+/-3.7 mm with 2D guidance (p < .001). Conclusions: 3D TRUS may provide more accurate HDR-BT needle localization than conventional 2D TRUS guidance for the majority of HDR-BT needles.

  5. Endoscopic Therapeutic Device Using Focused Ultrasonic Small Transducer

    NASA Astrophysics Data System (ADS)

    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.

  6. Characterization of dielectric electroactive polymer transducers

    NASA Astrophysics Data System (ADS)

    Nielsen, Dennis; Møller, Martin B.; Sarban, Rahimullah; Lassen, Benny; Knott, Arnold; Andersen, Michael A. E.

    2014-03-01

    Throughout this paper, a small-signal model of the Dielectric Electro Active Polymer (DEAP) transducer is analyzed. 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 guidelines for design optimization, accurate characterization of the transducer must be established. A small signal model of the DEAP transducer is derived and its validity is investigated using impedance measurements. Impedance measurements are shown for a push-pull DEAP based loudspeaker, and the dependency of the biasing voltage is explained. A measuring setup is proposed, which allows the impedance to be measured, while the DEAP transducer is connected to its biasing source.

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

    SciTech Connect

    Xia, Wenfeng Desjardins, Adrien E.; Mari, Jean Martial; West, Simeon J.; Ginsberg, Yuval; David, Anna L.; Ourselin, Sebastien

    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

  8. Biomechanical performance of new cardiovascular needles.

    PubMed

    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

  9. Brachytherapy needle deflection evaluation and correction

    SciTech Connect

    Wan Gang; Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

    2005-04-01

    In prostate brachytherapy, an 18-gauge needle is used to implant radioactive seeds. This thin needle can be deflected from the preplanned trajectory in the prostate, potentially resulting in a suboptimum dose pattern and at times requiring repeated needle insertion to achieve optimal dosimetry. In this paper, we report on the evaluation of brachytherapy needle deflection and bending in test phantoms and two approaches to overcome the problem. First we tested the relationship between needle deflection and insertion depth as well as whether needle bending occurred. Targeting accuracy was tested by inserting a brachytherapy needle to target 16 points in chicken tissue phantoms. By implanting dummy seeds into chicken tissue phantoms under 3D ultrasound guidance, the overall accuracy of seed implantation was determined. We evaluated methods to overcome brachytherapy needle deflection with three different insertion methods: constant orientation, constant rotation, and orientation reversal at half of the insertion depth. Our results showed that needle deflection is linear with needle insertion depth, and that no noticeable bending occurs with needle insertion into the tissue and agar phantoms. A 3D principal component analysis was performed to obtain the population distribution of needle tip and seed position relative to the target positions. Our results showed that with the constant orientation insertion method, the mean needle targeting error was 2.8 mm and the mean seed implantation error was 2.9 mm. Using the constant rotation and orientation reversal at half insertion depth methods, the deflection error was reduced. The mean needle targeting errors were 0.8 and 1.2 mm for the constant rotation and orientation reversal methods, respectively, and the seed implantation errors were 0.9 and 1.5 mm for constant rotation insertion and orientation reversal methods, respectively.

  10. Solar cell angular position transducer

    NASA Technical Reports Server (NTRS)

    Sandford, M. C.; Gray, D. L. (Inventor)

    1980-01-01

    An angular position transducer utilizing photocells and a light source is disclosed. The device uses a fully rotatable baffle which is connected via an actuator shaft to the body whose rotational displacement is to be measured. The baffle blocks the light path between the light source and the photocells so that a constant semicircular beam of light reaches the photocells. The current produced by the photocells is fed through a resistor, a differential amplifier measures the voltage drop across the resistor which indicates the angular position of the actuator shaft and hence of the object.

  11. Shear wave transducer for boreholes

    DOEpatents

    Mao, N.H.

    1984-08-23

    A technique and apparatus is provided for estimating in situ stresses by measuring stress-induced velocity anisotropy around a borehole. Two sets each of radially and tangentially polarized transducers are placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times are measured by both a pulsed phase-locked loop technique and a cross correlation of digitized waveforms. The biaxial velocity data are used to back-calculate the applied stress.

  12. Analog circuit for controlling acoustic transducer arrays

    DOEpatents

    Drumheller, Douglas S.

    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.

  13. ERROR COMPENSATOR FOR A POSITION TRANSDUCER

    DOEpatents

    Fowler, A.H.

    1962-06-12

    A device is designed for eliminating the effect of leadscrew errors in positioning machines in which linear motion of a slide is effected from rotary motion of a leadscrew. This is accomplished by providing a corrector cam mounted on the slide, a cam follower, and a transducer housing rotatable by the follower to compensate for all the reproducible errors in the transducer signal which can be related to the slide position. The transducer has an inner part which is movable with respect to the transducer housing. The transducer inner part is coupled to the means for rotating the leadscrew such that relative movement between this part and its housing will provide an output signal proportional to the position of the slide. The corrector cam and its follower perform the compensation by changing the angular position of the transducer housing by an amount that is a function of the slide position and the error at that position. (AEC)

  14. TRPC channels as signal transducers.

    PubMed

    Glazebrook, Patricia A; Schilling, William P; Kunze, Diana L

    2005-10-01

    The study of the TRPC cation channels as signal transducers in sensory neurons is in its infancy. Mechanoreceptors that monitor arterial pressure are prime candidates for the involvement of TRPC channels as either primary mechanical transducers or as modulators of the transduction process. Their activity patterns can be regulated by growth factors such as BDNF and by a variety of ligands that activate Gq-coupled receptors, mechanisms that have been shown in heterologous expression systems to activate TRPC channels. We investigated the distribution of TRPC1 and TRPC3-7 in nodose sensory neurons and in their peripheral axons that terminate as mechanosensitive receptors in the aortic arch of the rat. Using immunocytochemical techniques we identified these six TRPC proteins in the soma of the nodose neurons but only TRPC1 and TRPC3-5 were found to distribute to the peripheral axons and the mechanosensory terminals. TRPC1 and TRPC3 extended into the low threshold complex sensory endings with very strong labeling. In contrast, TRPC4 and TRPC5 were found primarily in major branches of the receptor but immunoreactivity was weak in the region where mechanotransduction is presumed to occur. Terminals arising from unmyelinated fibers also expressed TRPC1 and TRPC3-5 but not all fibers expressed all of the channels suggesting that specific TRPC protein may be aligned with previously described subclasses of the unmyelinated C-fibers. PMID:15971079

  15. Silicon Integrated Cavity Optomechanical Transducer

    NASA Astrophysics Data System (ADS)

    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.

  16. Two-Element Transducer for Ultrasound

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H.; Heyser, R. C.

    1986-01-01

    Separation of transmitting and receiving units improves probing of deep tissue. Ultrasonic transducer has dual elements to increase depth at which sonic images are made of biological tissue. Transducer uses separate transmitting and receiving elements, and frequency response of receiving element independently designed to accommodate attenuation of higher frequencies by tissue. New transducer intended for pulse-echo ultrasonic systems in which reflected sound pulses reveal features in tissue.

  17. Measurement methods of ultrasonic transducer sensitivity.

    PubMed

    Xiao, Dingguo; Fan, Qiong; Xu, Chunguang; Zhang, Xiuhua

    2016-05-01

    Sensitivity is an important parameter to describe the electro-acoustic energy conversion efficiency of ultrasonic transducer. In this paper, the definition of sensitivity and reciprocity of ultrasonic transducer is studied. The frequency response function of a transducer is the spectrum of its sensitivity, which reflects the response sensitivity of the transducer for input signals at different frequencies. Four common methods which are used to measure the disc-vibrator transducer sensitivity are discussed in current investigation. The reciprocity method and the pulse-echo method are based on the reciprocity of the transducer. In the laser vibrometer method measurement, the normal velocity on the transducer radiating surface is directly measured by a laser vibrometer. In the measurement process of the hydrophone method, a calibrated hydrophone is used to measure the transmitted field. The validity of these methods is checked by experimental test. All of the four methods described are sufficiently accurate for transducer sensitivity measurement, while each method has its advantages and limitations. In practical applications, the appropriate method to measure transducer sensitivity should be selected based on actual conditions. PMID:26953638

  18. A Beamforming Study for Implementation of Vibro-acoustography with a 1.75D Array Transducer

    PubMed Central

    Urban, Matthew W.; Chalek, Carl; Haider, Bruno; Thomenius, Kai E.; Fatemi, Mostafa; Alizad, Azra

    2013-01-01

    Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, Δf, to vibrate tissue at Δf. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using one-dimensional (1D) linear array transducers. In this article, we discuss VA beamforming and image formation using a 1.75D array transducer. A 1.75D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75D array over a 1D linear array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75D array transducer offers several advantages over scanning with a linear array transducer including improved image resolution and contrast due to better elevation focusing of the imaging point-spread function. PMID:23475919

  19. Simulation and fabrication of 0-3 composite PZT films for ultrahigh frequency (100-300 MHz) ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoyang; Fei, Chunlong; Chen, Zeyu; Chen, Ruimin; Yu, Ping; Chen, Zhongping; Shung, K. Kirk; Zhou, Qifa

    2016-03-01

    This paper presents simulation, fabrication, and characterization of single-element ultrahigh frequency (100-300-MHz) needle ultrasonic transducers based on 0-3 composite Pb(Zr0.52Ti0.48)O3 (PZT) films prepared by using composite ceramic sol-gel film and sol-infiltration technique. The center frequency of the developed transducer at 300-MHz was the highest frequency of PbTiO3 ceramic-based ultrasonic transducers ever reported. Furthermore, a brief description of the composite model was followed by the development of a new expression for predicting the longitudinal velocity, the clamped dielectric constant, and the complex electromechanical coupling coefficient kt of these films, which is very important in ultrasonic transducer design. Moreover, these parameters are difficult to obtain by measuring the frequency dependence of impedance and phase angle because of the weak signal of the previous 0-3 composite films transducer (>100 MHz). The modeling results show that the Cubes model with a geometric factor n = 0.05 fits well with the measured data. This model will be helpful for developing the 0-3 composite systems for ultrahigh frequency ultrasonic transducer design.

  20. A beamforming study for implementation of vibro-acoustography with a 1.75-D array transducer.

    PubMed

    Urban, Matthew W; Chalek, Carl; Haider, Bruno; Thomenius, Kai E; Fatemi, Mostafa; Alizad, Azra

    2013-03-01

    Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, Δf, to vibrate tissue at Δf. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using 1-D linear-array transducers. In this article, we discuss VA beamforming and image formation using a 1.75-D array transducer. A 1.75-D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75-D array over a 1-D linear-array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75-D array transducer offers several advantages over scanning with a linear-array transducer, including improved image resolution and contrast resulting from better elevation focusing of the imaging point-spread function. PMID:23475919

  1. Dry needling — peripheral and central considerations

    PubMed Central

    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 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. PMID:23115475

  2. Accuracy of Core Needle Biopsy Versus Fine Needle Aspiration Cytology for Diagnosing Salivary Gland Tumors

    PubMed Central

    Song, In Hye; Song, Joon Seon; Sung, Chang Ohk; Roh, Jong-Lyel; Choi, Seung-Ho; Nam, Soon Yuhl; Kim, Sang Yoon; Lee, Jeong Hyun; Baek, Jung Hwan; Cho, Kyung-Ja

    2015-01-01

    Background: Core needle biopsy is a relatively new technique used to diagnose salivary gland lesions, and its role in comparison with fine needle aspiration cytology needs to be refined. Methods: We compared the results of 228 ultrasound-guided core needle biopsy and 371 fine needle aspiration procedures performed on major salivary gland tumors with their postoperative histological diagnoses. Results: Core needle biopsy resulted in significantly higher sensitivity and more accurate tumor subtyping, especially for malignant tumors, than fine needle aspiration. No patient developed major complications after core needle biopsy. Conclusions: We recommend ultrasoundguided core needle biopsy as the primary diagnostic tool for the preoperative evaluation of patients with salivary gland lesions, especially when malignancy is suspected. PMID:26148740

  3. Standards for dielectric elastomer transducers

    NASA Astrophysics Data System (ADS)

    Carpi, Federico; Anderson, Iain; Bauer, Siegfried; Frediani, Gabriele; Gallone, Giuseppe; Gei, Massimiliano; Graaf, Christian; Jean-Mistral, Claire; Kaal, William; Kofod, Guggi; Kollosche, Matthias; Kornbluh, Roy; Lassen, Benny; Matysek, Marc; Michel, Silvain; Nowak, Stephan; O'Brien, Benjamin; Pei, Qibing; Pelrine, Ron; Rechenbach, Björn; Rosset, Samuel; Shea, Herbert

    2015-10-01

    Dielectric elastomer transducers consist of thin electrically insulating elastomeric membranes coated on both sides with compliant electrodes. They are a promising electromechanically active polymer technology that may be used for actuators, strain sensors, and electrical generators that harvest mechanical energy. The rapid development of this field calls for the first standards, collecting guidelines on how to assess and compare the performance of materials and devices. This paper addresses this need, presenting standardized methods for material characterisation, device testing and performance measurement. These proposed standards are intended to have a general scope and a broad applicability to different material types and device configurations. Nevertheless, they also intentionally exclude some aspects where knowledge and/or consensus in the literature were deemed to be insufficient. This is a sign of a young and vital field, whose research development is expected to benefit from this effort towards standardisation.

  4. New KNN-based lead-free piezoelectric ceramic for high-frequency ultrasound transducer applications

    NASA Astrophysics Data System (ADS)

    Ou-Yang, Jun; Zhu, Benpeng; Zhang, Yue; Chen, Shi; Yang, Xiaofei; Wei, Wei

    2015-03-01

    Based on new KNN-based piezoelectric material 0.96(K0.48Na0.52)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 with a giant d33 of 490, a 37-MHz high-frequency ultrasound needle transducer with the aperture size of 1 mm was successfully fabricated. The obtained transducer had a high electromechanical coupling factor k t of 0.55, a good bandwidth of 56.8 % at -6 dB, and a low insertion loss of -16 dB at the central frequency. Its excellent performance is comparable to lead-containing transducer and is superior to that of any other lead-free transducer. This promising result demonstrates that this new KNN-based lead-free piezoelectric ceramic is a good candidate to replace lead-based materials for high-frequency ultrasound imaging.

  5. Navigational transbronchial needle aspiration, percutaneous needle aspiration and its future.

    PubMed

    Arias, Sixto; Yarmus, Lonny; Argento, A Christine

    2015-12-01

    Peripheral lung nodule evaluation represents a clinical challenge. Given that many nodules will be incidentally found with lung cancer screening following the publication of the National Lung Screening Trial (NLST), the goal is to find an accurate, safe and minimally-invasive diagnostic modality to biopsy the concerning lesions. Unfortunately, conventional bronchoscopic techniques provide a poor diagnostic yield of 18-62%. In recent years advances in technology have led to the introduction of electromagnetic navigational bronchoscopy (ENB) as a tool to guide sampling of peripheral lung nodules. The same principle has also recently been expanded and applied to the transthoracic needle biopsy, referred to as electromagnetic transthoracic needle aspiration (E-TTNA). An improved diagnostic yield has afforded this technology a recommendation by the 2013 3(rd) Edition ACCP Guidelines for the Diagnosis and Management of Lung Cancer which state that "in patients with peripheral lung lesions difficult to reach with conventional bronchoscopy, ENB is recommended if the equipment and the expertise are available (Grade 1C)". In this review we will discuss the technology, devices that are available, techniques and protocols, diagnostic yield, safety, cost effectiveness and more. PMID:26807280

  6. Navigational transbronchial needle aspiration, percutaneous needle aspiration and its future

    PubMed Central

    Arias, Sixto; Yarmus, Lonny

    2015-01-01

    Peripheral lung nodule evaluation represents a clinical challenge. Given that many nodules will be incidentally found with lung cancer screening following the publication of the National Lung Screening Trial (NLST), the goal is to find an accurate, safe and minimally-invasive diagnostic modality to biopsy the concerning lesions. Unfortunately, conventional bronchoscopic techniques provide a poor diagnostic yield of 18–62%. In recent years advances in technology have led to the introduction of electromagnetic navigational bronchoscopy (ENB) as a tool to guide sampling of peripheral lung nodules. The same principle has also recently been expanded and applied to the transthoracic needle biopsy, referred to as electromagnetic transthoracic needle aspiration (E-TTNA). An improved diagnostic yield has afforded this technology a recommendation by the 2013 3rd Edition ACCP Guidelines for the Diagnosis and Management of Lung Cancer which state that “in patients with peripheral lung lesions difficult to reach with conventional bronchoscopy, ENB is recommended if the equipment and the expertise are available (Grade 1C)”. In this review we will discuss the technology, devices that are available, techniques and protocols, diagnostic yield, safety, cost effectiveness and more. PMID:26807280

  7. Technical Note: Comparison of traditional needle vaccination to pneumatic, needle-free vaccination in sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lateral transmission of blood-borne diseases can occur when a single needle is used repeatedly to vaccinate livestock. Needle-free technology to vaccinate sheep without damaging the carcass, causing lesions, and/or leaving needle fragments, and eliciting a similar antibody response to traditional n...

  8. Photoelastic transducer for high-temperature applications

    NASA Technical Reports Server (NTRS)

    Redner, A. S.; Adamovsky, Grigory; Wesson, L. N.

    1990-01-01

    A design for a birefringence transducer for high-temperature applications is described. The spring element and the readout instrumentation are addressed. A pressure transducer based on the concept has been built and successfully tested at temperatures up to 600 C.

  9. Opto-acoustic transducer for medical applications

    DOEpatents

    Benett, William; Celliers, Peter; Da Silva, Luiz; Glinsky, Michael; London, Richard; Maitland, Duncan; Matthews, Dennis; Krulevich, Peter; Lee, Abraham

    1999-01-01

    This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

  10. Opto-acoustic transducer for medical applications

    DOEpatents

    Benett, W.; Celliers, P.; Da Silva, L.; Glinsky, M.; London, R.; Maitland, D.; Matthews, D.; Krulevich, P.; Lee, A.

    1999-08-31

    This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control. 7 figs.

  11. Opto-acoustic transducer for medical applications

    DOEpatents

    Benett, William; Celliers, Peter; Da Silva, Luiz; Glinsky, Michael; London, Richard; Maitland, Duncan; Matthews, Dennis; Krulevich, Peter; Lee, Abraham

    2002-01-01

    This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

  12. Hot foil transducer skin friction sensor

    NASA Technical Reports Server (NTRS)

    Vranas, T. (Inventor)

    1982-01-01

    The device utilizes foil transducers with only one edge exposed to the fluid flow. The surfaces are polished producing a foil transducer that does not generate turbulence while sufficiently thick to carry the required electrical current for high temperature fluid flow. The assembly utilizes a precut layered metal sandwich with attached electrodes eliminating a need for welding and individual sensor calibration.

  13. Piezoelectric materials used in underwater acoustic transducers

    SciTech Connect

    Li, Huidong; Deng, Zhiqun; Carlson, Thomas J.

    2012-07-07

    Piezoelectric materials have been used in underwater acoustic transducers for nearly a century. In this paper, we reviewed four different types of piezoelectric materials: piezoelectric ceramics, single crystals, composites, and polymers, which are widely used in underwater acoustic transducers nowadays. Piezoelectric ceramics are the most dominant material type and are used as a single-phase material or one of the end members in composites. Piezoelectric single crystals offer outstanding electromechanical response but are limited by their manufacturing cost. Piezoelectric polymers provide excellent acoustic impedance matching and transducer fabrication flexibility although their piezoelectric properties are not as good as ceramics and single crystals. Composites combined the merits of ceramics and polymers and are receiving increased attention. The typical structure and electromechanical properties of each type of materials are introduced and discussed with respect to underwater acoustic transducer applications. Their advantages and disadvantages are summarized. Some of the critical design considerations when developing underwater acoustic transducers with these materials are also touched upon.

  14. Thermodynamic Pressure/Temperature Transducer Health Check

    NASA Technical Reports Server (NTRS)

    Immer, Christopher D. (Inventor); Eckhoff, Anthony (Inventor); Medelius, Pedro J. (Inventor); Deyoe, Richard T. (Inventor); Starr, Stanley O. (Inventor)

    2004-01-01

    A device and procedure for checking the health of a pressure transducer in situ is provided. The procedure includes measuring a fixed change in pressure above ambient pressure and a fixed change in pressure below ambient pressure. This is done by first sealing an enclosed volume around the transducer with a valve. A piston inside the sealed volume is increasing the pressure. A fixed pressure below ambient pressure is obtained by opening the valve, driving the piston The output of the pressure transducer is recorded for both the overpressuring and the underpressuring. By comparing this data with data taken during a preoperative calibration, the health of the transducer is determined from the linearity, the hysteresis, and the repeatability of its output. The further addition of a thermometer allows constant offset error in the transducer output to be determined.

  15. Geographical and climatic limits of needle types of one- and two-needled pinyon pines

    USGS Publications Warehouse

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

    2008-01-01

    Aim: The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. Location: Western North America. Methods: We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. Results: The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes

  16. Using Portable Transducers to Measure Tremor Severity

    PubMed Central

    Elble, Rodger J.; McNames, James

    2016-01-01

    Background Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor. Methods Medline was searched via PubMed.gov in December 2015 using the Boolean expression “tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer).” Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, and 105 papers written in English were reviewed in detail. Results Accelerometers, gyroscopes, and digitizing tablets are used most commonly, but few are sold for the purpose of measuring tremor. Consequently, most software for tremor analysis is developed by the user. Wearable transducers are capable of recording tremor continuously, in the absence of a clinician. Tremor amplitude, frequency, and occurrence (percentage of time with tremor) can be computed. Tremor amplitude and occurrence correlate strongly with clinical ratings of tremor severity. Discussion Transducers provide measurements of tremor amplitude that are objective, precise, and valid, but the precision and accuracy of transducers are mitigated by natural variability in tremor amplitude. This variability is so great that the minimum detectable change in amplitude, exceeding random variability, is comparable for scales and transducers. Research is needed to determine the feasibility of detecting smaller change using averaged data from continuous long-term recordings with wearable transducers. PMID:27257514

  17. [Clinical experiences of RUAN's needling method for insomnia].

    PubMed

    Jiang, Ling-Zhen; Ruan, Bu-Qing

    2013-07-01

    The theoretical basis and needling techniques of RUAN's needling method in treatment of insomnia are introduced in this paper. Ruan's needling method follows the theory of traditional Chinese medicine and acupuncture, stresses the theory of taking brain as the marrow sea in treatment of insomnia acupuncture. The characteristics of his needling method are that emphasis on acupoints, including positioning accuracy and proper compatibility; think highly of needling method that combines with perpendicular needling, oblique needling, parallel needling, deep needling and shallow needling; emphasis on manipulation and identify qi under the needle to decide reinforcing or reducing method by arrival of qi, excess or deficiency. And the clinical observation of RUAN' s needling method on 30 cases of insomnia is attached. PMID:24032204

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

    MedlinePlus

    ... 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 ...

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

    NASA Astrophysics Data System (ADS)

    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.

  20. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5580 Acupuncture needle....

  1. Needle Exchange Programs and Drug Injection Behavior

    ERIC Educational Resources Information Center

    DeSimone, Jeff

    2005-01-01

    This study examines how drug injection and needle sharing propensities respond when a needle exchange program (NEP) is introduced into a city. I analyze 1989-1995 Drug Use Forecasting data on adult male arrestees from 24 large U.S. cities, in nine of which NEPs opened during the sample period. After controlling for cocaine and heroin prices, AIDS…

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

    PubMed

    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

  3. Laser needle guide for the sonic flashlight.

    PubMed

    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

  4. A comparison of needle bending models.

    PubMed

    Dehghan, Ehsan; Goksel, Orcun; Salcudean, Septimiu E

    2006-01-01

    Modeling the deflection of flexible needles is an essential part of needle insertion simulation and path planning. In this paper, three models are compared in terms of accuracy in simulating the bending of a prostate brachytherapy needle. The first two utilize the finite element method, one using geometric non-linearity and triangular plane elements, the other using non-linear beam elements. The third model uses angular springs to model cantilever deflection. The simulations are compared with the experimental bent needle configurations. The models are assessed in terms of geometric conformity using independently identified and pre-identified model parameters. The results show that the angular spring model, which is also the simplest, simulates the needle more accurately than the others. PMID:17354904

  5. Single crystal cylinder transducers for sonar applications

    NASA Astrophysics Data System (ADS)

    Robinson, Harold; Stevens, Gerald; Buffman, Martin; Powers, James

    2005-04-01

    A segmented cylinder transducer constructed of single crystal lead magnesium niobate-lead titanate (PMN-PT) has been under development at NUWC and EDO Corporation for several years. The purpose of this development was to provide an extremely compact, high power broadband source. By virtue of their extraordinary material properties, ferroelectric single crystals are the ideal transduction material for developing such compact broadband systems. This presentation shall review the evolution of the transducer design as well as present the results of a successful in-water test conducted at NUWC in October of 2003. It shall be shown that design changes intended to eliminate spurious modes limiting the transducer bandwidth first observed in 2002 were successful, resulting in a transducer with a clean frequency response and an effective coupling factor of 0.85. The measured transducer admittance was in nearly exact agreement with theoretical predictions. The NUWC in-water tests demonstrated that the single crystal cylinder achieved an admittance bandwidth (based on the Stansfield criterion) of over 100%, while the tuned power factor was 0.8 or more over 2.5 octaves of frequency. Additionally, the transducer produced 12 dB higher source levels than a similarly sized PZT transducer. [Work sponsored by DARPA.

  6. Low power consumption current transducer

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T. (Inventor)

    1989-01-01

    A low power consumption current transducer utilizes a saturable core reactor which includes a pair of opposed gate windings and a control winding. The control winding of the saturable reactor is arranged to receive the current to be measured. A square wave generator is connected to the gate winding of the transformer connected across the square wave generator and the secondary connected in series with the gate windings of the reactor. A full wave rectifier is connected to the gate windings and a resistor is connected across the rectifier to provide a DC voltage to cross it representative of the current flow through the control winding. A DC power supply is provided to supply power to the square wave voltage source. A diode is connected between each end of the primary winding of the transformer and one polarity of the DC power supply to commutate the reactive current resulting from the counter emf generated in the reactor back to the DC supply to eliminate potentially damaging reactive voltage spikes which would otherwise appear at the output of the square wave generator and conserve energy.

  7. Seismic transducer modeling using ABAQUS

    SciTech Connect

    Stephen R. Novascone

    2004-05-01

    A seismic transducer, known as an orbital vibrator, consists of a rotating imbalance driven by an electric motor. When suspended in a liquid-filled wellbore, vibrations of the device are coupled to the surrounding geologic media. In this mode, an orbital vibrator can be used as an efficient rotating dipole source for seismic imaging. Alternately, the motion of an orbital vibrator is affected by the physical properties of the surrounding media. From this point of view, an orbital vibrator can be used as a stand-alone sensor. The reaction to the surroundings can be sensed and recorded by geophones inside the orbital vibrator. These reactions are a function of the media’s physical properties such as modulus, damping, and density, thereby identifying the rock type. This presentation shows how the orbital vibrator and surroundings were modeled with an ABAQUS acoustic FEM. The FEM is found to compare favorably with theoretical predictions. A 2D FEM and analytical model are compared to an experimental data set. Each model compares favorably with the data set.

  8. Radiofrequency Cauterization with Biopsy Introducer Needle

    PubMed Central

    Pritchard, William F.; Wray-Cahen, Diane; Karanian, John W.; Hilbert, Stephen; Wood, Bradford J.

    2014-01-01

    PURPOSE The principal risks of needle biopsy are hemorrhage and implantation of tumor cells in the needle tract. This study compared hemorrhage after liver and kidney biopsy with and without radiofrequency (RF) ablation of the needle tract. MATERIALS AND METHODS Biopsies of liver and kidney were performed in swine through introducer needles modified to allow RF ablation with the distal 2 cm of the needle. After each biopsy, randomization determined whether the site was to undergo RF ablation during withdrawal of the introducer needle. Temperature was measured with a thermistor stylet near the needle tip, with a target temperature of 70°C–100°C with RF ablation. Blood loss was measured as grams of blood absorbed in gauze at the puncture site for 2 minutes after needle withdrawal. Selected specimens were cut for gross examination. RESULTS RF ablation reduced bleeding compared with absence of RF ablation in liver and kidney (P < .01), with mean blood loss reduced 63% and 97%, respectively. Mean amounts of blood loss (±SD) in the liver in the RF and no-RF groups were 2.03 g ± 4.03 (CI, 0.53–3.54 g) and 5.50 g ± 5.58 (CI, 3.33–7.66 g), respectively. Mean amounts of blood loss in the kidney in the RF and no-RF groups were 0.26 g ± 0.32 (CI, −0.01 to 0.53 g) and 8.79 g ± 7.72 (CI, 2.34–15.24 g), respectively. With RF ablation, thermal coagulation of the tissue surrounding the needle tract was observed. CONCLUSION RF ablation of needle biopsy tracts reduced hemorrhage after biopsy in the liver and kidney and may reduce complications of hemorrhage as well as implantation of tumor cells in the tract. PMID:14963187

  9. A solid-state phase-insensitive ultrasonic transducer

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1979-01-01

    Photoconductive acoustoelectric transducer (AET) functions as phase-insensitive ultrasonic transducer. Device is easy to use and requires no additional noisy components such as light or thermal source.

  10. Hybrid piezoelectric energy harvesting transducer system

    NASA Technical Reports Server (NTRS)

    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.

  11. Apical pressures developed by needles for canal irrigation.

    PubMed

    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

  12. Fundamentals of heat measurement. [heat flux transducers

    NASA Technical Reports Server (NTRS)

    Gerashchenko, O. A.

    1979-01-01

    Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual (isolated) heat flux transducers subject to space and time-dependent loading. An analysis of the properties of stacked (series-connected) transducers of various types (sandwich-type, plane, and spiral) is used to derive a similarity theory providing general governing relationships. The transducers examined are used in 36 types of derivative devices involving direct heat loss measurements, heat conduction studies, radiation pyrometry, calorimetry in medicine and industry and nuclear reactor dosimetry.

  13. Innovations in piezoelectric materials for ultrasound transducers

    NASA Astrophysics Data System (ADS)

    Shrout, Thomas R.; Park, Seung Eek E.; Lopath, Patrick D.; Meyer, Richard J., Jr.; Ritter, Timothy A.; Shung, K. Kirk

    1998-05-01

    Piezoelectric material lie at the heart of ultrasonic transducers. Recent advances in materials development include submicron piezoelectric ceramics (PZT) which lead to improvements in feature size, i.e. aspect ratio, element width, etc., for linear arrays and high frequency transducers. In contrast to fine grain ceramics, single crystal materials based on Relaxor-PT ferroelectrics offer electromechanical coupling coefficients > 90 percent with a range of dielectric permittivity allowing flexibility in transducer engineering in regard to electrical impedance matching. Using KLM modeling, very high bandwidth performance > 120 percent is projected. Specific examples of high frequency 1-3 composites and 1D linear array transducers fabricated from new piezoelectric materials, including sol-gel derived PZT fibers, are presented.

  14. Improved transducer for squeeze-film bearings

    NASA Technical Reports Server (NTRS)

    Hoogenbloom, L.

    1971-01-01

    Transducer amplifies vibrations produced by piezoelectric drivers, creating greater amplitudes than were possible with direct drive devices. Drivers isolated from bearing surfaces result in bearings with high axial load capacity and stiffness, thus, wear on ceramic cylinders is reduced.

  15. Portable high precision pressure transducer system

    DOEpatents

    Piper, Thomas C.; Morgan, John P.; Marchant, Norman J.; Bolton, Steven M.

    1994-01-01

    A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.

  16. AUTOMATIC CALIBRATING SYSTEM FOR PRESSURE TRANSDUCERS

    DOEpatents

    Amonette, E.L.; Rodgers, G.W.

    1958-01-01

    An automatic system for calibrating a number of pressure transducers is described. The disclosed embodiment of the invention uses a mercurial manometer to measure the air pressure applied to the transducer. A servo system follows the top of the mercury column as the pressure is changed and operates an analog- to-digital converter This converter furnishes electrical pulses, each representing an increment of pressure change, to a reversible counterThe transducer furnishes a signal at each calibration point, causing an electric typewriter and a card-punch machine to record the pressure at the instant as indicated by the counter. Another counter keeps track of the calibration points so that a number identifying each point is recorded with the corresponding pressure. A special relay control system controls the pressure trend and programs the sequential calibration of several transducers.

  17. Portable high precision pressure transducer system

    DOEpatents

    Piper, T.C.; Morgan, J.P.; Marchant, N.J.; Bolton, S.M.

    1994-04-26

    A high precision pressure transducer system is described for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display. 2 figures.

  18. A magnifying scratch-gage force transducer

    NASA Technical Reports Server (NTRS)

    Scott, C. E.

    1969-01-01

    Single-component scratch-gage transducer incorporates a unique motion magnification scheme to increase the magnitude of the load measuring scratch approximately 15 times over that of conventional models. It is small, load carrying and high in natural frequency.

  19. Micromachined Tunneling Displacement Transducers for Physical Sensors

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Kaiser, W. J.; Podosek, J. A.; Rockstad, H. K.; Reynolds, J. K.; Vote, E. C.

    1993-01-01

    We have designed and constructed a series of tunneling sensors which take advantage of the extreme position sensitivity of electron tunneling. In these sensors, a tunneling displacement transducer, based on scanning tunneling microscopy principles, is used to detect the signal-induced motion of a sensor element. Through the use of high-resonant frequency mechanical elements for the transducer, sensors may be constructed which offer wide bandwidth, and are robust and easily operated. Silicon micromachining may be used to fabricate the transducer elements, allowing integration of sensor and control electronics. Examples of tunneling accelerometers and infrared detectors will be discussed. In each case, the use of the tunneling transducer allows miniaturization of the sensor as well as enhancement of the sensor performance.

  20. Guided wave applications of piezocomposite transducers

    SciTech Connect

    Meyer, P.A.; Rose, J.L.

    1996-12-31

    The majority of ultrasonic nondestructive testing applications in use today utilize longitudinal wave techniques. These are very effective for flaw detection and thickness measurement in scanning applications. In sheet and tube type materials, however, a more rapid technique has been developed utilizing Guided Wave Inspection. This method is capable of interrogating large areas of the material without extensive transducer scanning. An important requirement in this method is the ability to utilize relatively broad bandwidth transducers in the test. This paper presents the concepts on which Guided Wave Inspection is based as well as piezocomposite transducer incorporate a combination of piezoelectric ceramics and polymers to enhance the ultrasonic performance of the device. Additionally, the transducer can be designed to match to non-planar surfaces increasing its versatility when a difficult shape is involved.

  1. Development of an inherently digital transducer

    NASA Technical Reports Server (NTRS)

    Richard, R. R.

    1972-01-01

    The term digital transducer normally implies the combination of conventional analog sensors with encoders or analog-to-digital converters. Because of the objectionable characteristics of most digital transducers, a program was instituted to investigate the possibility of producing a transducer that is inherently digital, instead of a transducer that is digital in the usual sense. Such a device would have improved accuracy and reliability and would have reduced power and bulk requirements because two processes, sensing and conditioning, would be combined into one processes. A Curie-point-temperature sensor is described that represents realization of the stated goal. Also, a metal-insulator semiconductor is described that does not conform precisely to the program goals but that appears to have applications as a new and interesting transduction device.

  2. Development of a tethered satellite force transducer

    NASA Astrophysics Data System (ADS)

    Rhew, Ray D.

    The SEDS (Small Expendable Deployer System)/Delta II is a demonstration flight of a tethered satellite deployer system. The satellite or end mass payload, which is deployed and tethered to the Delta II rocket, is instrumented to determine its dynamics during deployment. A three-component force transducer or strain-gage balance was developed to measure tether tension on the end-mass side of the tether. The transducer was designed to measure tensions up to 20N in each direction and resolve tensions as low as 0.002N. In addition, the transducer was required to withstand the shock, vibration, and temperature excursions of the mission. The development of the transducer from design to testing and integration is discussed.

  3. Federal funding for needle exchange programs.

    PubMed

    Clark, Peter A; Fadus, Matthew

    2010-01-01

    The HIV/AIDS pandemic has affected millions across the globe. The sharing of needles, for reasons of economy or social relations, has become the most common mode of HIV transmission among injection drug users. Needle exchange programs, which provide many services in addition to the exchange of clean needles for contaminated needles, have proven effective in reducing HIV rates among injection drug users in their communities. Although these programs have proven to be one of the most effective strategies in the efforts to reduce HIV rates, there has been a federal ban on the use of federal money for needle exchange programs since 1989. This ban was introduced by Congress in accordance with the drug war ideology, a narrow and elusive plan to completely eradicate drug use in the United States. Although there are a significant number of government reports supporting needle exchange programs, including support from the CDC, American Medical Association, the National Institutes of Health, it appears as If public health and the lives of others have become a secondary concern to strong federal policy on eradicating drug use. Lifting the federal ban would save the country millions of lives and billions of dollars in healthcare costs. Needle exchange programs should be an integral part of HIV prevention strategy, and are ethically imperative as well, restoring human dignity to the clients that so often need it.
    PMID:20037499

  4. Ultrasonic transducer for extreme temperature environments

    DOEpatents

    Light, Glenn M.; Cervantes, Richard A.; Alcazar, David G.

    1993-03-23

    An ultrasonic piezoelectric transducer that is operable in very high and very low temperatures. The transducer has a dual housing structure that isolates the expansion and contraction of the piezoelectric element from the expansion and contraction of the housing. Also, the internal components are made from materials having similar coefficients of expansion so that they do not interfere with the motion of the piezoelectric element.

  5. High energy, low frequency, ultrasonic transducer

    DOEpatents

    Brown, Albert E.

    2000-01-01

    A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod. The ultrasonic transducer has use in the acoustic inspection of long (40+foot) architectural reinforcements and structural supporting members, such as in bridges and dams.

  6. Resonant capacitive MEMS acoustic emission transducers

    NASA Astrophysics Data System (ADS)

    Ozevin, D.; Greve, D. W.; Oppenheim, I. J.; Pessiki, S. P.

    2006-12-01

    We describe resonant capacitive MEMS transducers developed for use as acoustic emission (AE) detectors, fabricated in the commercial three-layer polysilicon surface micromachining process (MUMPs). The 1 cm square device contains six independent transducers in the frequency range between 100 and 500 kHz, and a seventh transducer at 1 MHz. Each transducer is a parallel plate capacitor with one plate free to vibrate, thereby causing a capacitance change which creates an output signal in the form of a current under a dc bias voltage. With the geometric proportions we employed, each transducer responds with two distinct resonant frequencies. In our design the etch hole spacing was chosen to limit squeeze film damping and thereby produce an underdamped vibration when operated at atmospheric pressure. Characterization experiments obtained by capacitance and admittance measurements are presented, and transducer responses to physically simulated AE source are discussed. Finally, we report our use of the device to detect acoustic emissions associated with crack initiation and growth in weld metal.

  7. Absolute calibration technique for broadband ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    1994-01-01

    Calibrating an ultrasonic transducer can be performed with a reduced number of calculations and testing. A wide-band pulser is connected to an ultrasonic transducer under test to generate ultrasonic waves in a liquid. A single frequency is transmitted to the electrostatic acoustic transducer (ESAT) and the voltage change produced is monitored. Then a broadband ultrasonic pulse is generated by the ultrasonic transducer and received by the ESAT. The output of the ESAT is amplified and input to a digitized oscilloscope for fast Fourier transform. The resulting plot is normalized with the monitored signal from the single frequency pulse. The plot is then corrected for characteristics of the membrane and diffraction effects. The transfer function of the final plot is determined. The transfer function gives the final sensitivity of the ultrasonic transducer as a function of frequency. The advantage of the system is the speed of calibrating the transducer by a reduced number of measurements and removal of the membrane and diffraction effects.

  8. Fine-needle aspiration by vacuum tubes.

    PubMed

    Holmquist, N D

    1989-07-01

    Fine-needle aspiration of subcutaneous masses, accepted in many parts of Europe and the Americas as a routine diagnostic technique, employs a syringe holder to facilitate the creation of a vacuum to withdraw cells. This investigation demonstrates that a vacuum tube used in venipuncture can be used to supply the negative pressure to suck cells into the needle. This apparatus is more readily available than a syringe holder in hospitals and clinics, and particularly provides the operator with a more dexterous approach to the mass because the fingers holding the needle can be much closer to the mass being immobilized by the other hand. PMID:2750713

  9. Optimal needle design for minimal insertion force and bevel length.

    PubMed

    Wang, Yancheng; Chen, Roland K; Tai, Bruce L; McLaughlin, Patrick W; Shih, Albert J

    2014-09-01

    This research presents a methodology for optimal design of the needle geometry to minimize the insertion force and bevel length based on mathematical models of cutting edge inclination and rake angles and the insertion force. In brachytherapy, the needle with lower insertion force typically is easier for guidance and has less deflection. In this study, the needle with lancet point (denoted as lancet needle) is applied to demonstrate the model-based optimization for needle design. Mathematical models to calculate the bevel length and inclination and rake angles for lancet needle are presented. A needle insertion force model is developed to predict the insertion force for lancet needle. The genetic algorithm is utilized to optimize the needle geometry for two cases. One is to minimize the needle insertion force. Using the geometry of a commercial lancet needle as the baseline, the optimized needle has 11% lower insertion force with the same bevel length. The other case is to minimize the bevel length under the same needle insertion force. The optimized design can reduce the bevel length by 46%. Both optimized needle designs were validated experimentally in ex vivo porcine liver needle insertion tests and demonstrated the methodology of the model-based optimal needle design. PMID:24957487

  10. Pine needle abortion biomarker detected in bovine fetal fluids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. 21 CFR 870.2860 - Heart sound transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Heart sound transducer. 870.2860 Section 870.2860...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2860 Heart sound transducer. (a) Identification. A heart sound transducer is an external transducer that exhibits a change...

  12. 21 CFR 870.2860 - Heart sound transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heart sound transducer. 870.2860 Section 870.2860...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2860 Heart sound transducer. (a) Identification. A heart sound transducer is an external transducer that exhibits a change...

  13. 21 CFR 870.2860 - Heart sound transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Heart sound transducer. 870.2860 Section 870.2860...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2860 Heart sound transducer. (a) Identification. A heart sound transducer is an external transducer that exhibits a change...

  14. 21 CFR 870.2860 - Heart sound transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Heart sound transducer. 870.2860 Section 870.2860...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2860 Heart sound transducer. (a) Identification. A heart sound transducer is an external transducer that exhibits a change...

  15. 21 CFR 870.2860 - Heart sound transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Heart sound transducer. 870.2860 Section 870.2860...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2860 Heart sound transducer. (a) Identification. A heart sound transducer is an external transducer that exhibits a change...

  16. 21 CFR 870.2890 - Vessel occlusion transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vessel occlusion transducer. 870.2890 Section 870... transducer. (a) Identification. A vessel occlusion transducer is a device used to provide an electrical..., sound, and ultrasonic transducers. (b) Classification. Class II (performance standards)....

  17. 21 CFR 870.2890 - Vessel occlusion transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vessel occlusion transducer. 870.2890 Section 870... transducer. (a) Identification. A vessel occlusion transducer is a device used to provide an electrical..., sound, and ultrasonic transducers. (b) Classification. Class II (performance standards)....

  18. 21 CFR 870.2890 - Vessel occlusion transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vessel occlusion transducer. 870.2890 Section 870... transducer. (a) Identification. A vessel occlusion transducer is a device used to provide an electrical..., sound, and ultrasonic transducers. (b) Classification. Class II (performance standards)....

  19. 21 CFR 870.2890 - Vessel occlusion transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vessel occlusion transducer. 870.2890 Section 870... transducer. (a) Identification. A vessel occlusion transducer is a device used to provide an electrical..., sound, and ultrasonic transducers. (b) Classification. Class II (performance standards)....

  20. 21 CFR 870.2890 - Vessel occlusion transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vessel occlusion transducer. 870.2890 Section 870... transducer. (a) Identification. A vessel occlusion transducer is a device used to provide an electrical..., sound, and ultrasonic transducers. (b) Classification. Class II (performance standards)....

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

    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 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

  3. Sliding Mode Control of Steerable Needles

    PubMed Central

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

    2014-01-01

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

  4. Sliding Mode Control of Steerable Needles.

    PubMed

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

    2013-10-01

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

  5. Demand for superpremium needle cokes on upswing

    SciTech Connect

    Acciarri, J.A.; Stockman, G.H. )

    1989-12-01

    The authors discuss how recent supply shortages of super-premium quality needle cokes, plus the expectation of increased shortfalls in the future, indicate that refiners should consider upgrading their operations to fill these demands. Calcined, super-premium needle cokes are currently selling for as much as $550/metric ton, fob producer, and increasing demand will continue the upward push of the past year. Needle coke, in its calcined form, is the major raw material in the manufacture of graphite electrodes. Used in steelmaking, graphite electrodes are the electrical conductors that supply the heat source, through arcing electrode column tips, to electric arc steel furnaces. Needle coke is commercially available in three grades - super premium, premium, and intermediate. Super premium is used to produce electrodes for the most severe electric arc furnace steelmaking applications, premium for electrodes destined to less severe operations, and intermediate for even less critical needs.

  6. Science off the Sphere: Knitting Needles

    NASA Video Gallery

    International Space Station Expedition 30 astronaut Don Pettit uses knitting needles and water droplets to demonstrate physics in space for 'Science off the Sphere.' Through a partnership between N...

  7. Percutaneous needle biopsy of the irradiated skeleton

    SciTech Connect

    Edeiken, B.; deSantos, L.A.

    1983-03-01

    Percutaneous needle biopsy was performed in 20 patients who had radiologic abnormalities after irradiation of the skeleton. The biopsies were performed to determine the nature of the bone changes and to differentiate radiation necrosis from metastases or local tumor extension. Eleven patients had tumors, two of which were radiation-induced sarcomas; nine patients did not show evidence of tumor. One patient had osteomyelitis rather than the suspected tumor. The value of percutaneous needle biopsy in the postirradiated skeleton is discussed.

  8. Finite element model of needle electrode sensitivity

    NASA Astrophysics Data System (ADS)

    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.

  9. Dry needling versus acupuncture: the ongoing debate.

    PubMed

    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

  10. Review on Acoustic Transducers for Resonant Ultrasound Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nakamura, N.; Ogi, H.; Hirao, M.

    2015-08-01

    Determination of elastic constants using resonant ultrasound spectroscopy requires transducers that can measure resonance frequencies accurately and identify the vibrational mode of each resonance frequency. We developed three transducers, namely an electromagnetic acoustic transducer, a tripod piezoelectric transducer coupled with a laser Doppler interferometer, and an antenna transmission transducer, for use with various materials and in different measurement circumstances. Their capability in resonant ultrasound spectroscopy and their applications are described.

  11. Ultrasonic comb transducer for smart materials

    NASA Astrophysics Data System (ADS)

    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.

  12. High Temperature, High Power Piezoelectric Composite Transducers

    PubMed Central

    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

  13. High temperature, high power piezoelectric composite transducers.

    PubMed

    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

  14. Advanced Bode Plot Techniques for Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The Bode plot, displayed as either impedance or admittance versus frequency, is the most basic test used by ultrasonic transducer designers. With simplicity and ease-of-use, Bode plots are ideal for baseline comparisons such as spacing of parasitic modes or impedance, but quite often the subtleties that manifest as poor process control are hard to interpret or are nonexistence. In-process testing of transducers is time consuming for quantifying statistical aberrations, and assessments made indirectly via the workpiece are difficult. This research investigates the use of advanced Bode plot techniques to compare ultrasonic transducers with known "good" and known "bad" process performance, with the goal of a-priori process assessment. These advanced techniques expand from the basic constant voltage versus frequency sweep to include constant current and constant velocity interrogated locally on transducer or tool; they also include up and down directional frequency sweeps to quantify hysteresis effects like jumping and dropping phenomena. The investigation focuses solely on the common PZT8 piezoelectric material used with welding transducers for semiconductor wire bonding. Several metrics are investigated such as impedance, displacement/current gain, velocity/current gain, displacement/voltage gain and velocity/voltage gain. The experimental and theoretical research methods include Bode plots, admittance loops, laser vibrometry and coupled-field finite element analysis.

  15. Piezoelectric transducer design via multiobjective optimization.

    PubMed

    Fu, B; Hemsel, T; Wallaschek, J

    2006-12-22

    The design of piezoelectric transducers is usually based on single-objective optimization only. In most practical applications of piezoelectric transducers, however, there exist multiple design objectives that often are contradictory to each other by their very nature. It is impossible to find a solution at which each objective function gets its optimal value simultaneously. Our design approach is to first find a set of Pareto-optimal solutions, which can be considered to be best compromises among multiple design objectives. Among these Pareto-optimal solutions, the designer can then select the one solution which he considers to be the best one. In this paper we investigate the optimal design of a Langevin transducer. The design problem is formulated mathematically as a constrained multiobjective optimization problem. The maximum vibration amplitude and the minimum electrical input power are considered as optimization objectives. Design variables involve continuous variables (dimensions of the transducer) and discrete variables (the number of piezoelectric rings and material types). In order to formulate the optimization problem, the behavior of piezoelectric transducers is modeled using the transfer matrix method based on analytical models. Multiobjective evolutionary algorithms are applied in the optimization process and a set of Pareto-optimal designs is calculated. The optimized results are analyzed and the preferred design is determined. PMID:16814826

  16. Acoustooptic pulse-echo transducer system

    NASA Technical Reports Server (NTRS)

    Claus, R. O.; Wade, J. C.

    1983-01-01

    A pulse-echo transducer system which uses an ultrasonic generating element and an optical detection technique is described. The transmitting transducer consists of a concentric ring electrode pattern deposited on a circular, X-cut quartz substrate with a circular hole in the center. The rings are independently pulsed with a sequence high voltage signals phased in such a way that the ultrasonic waves generated by the separate rings superimpose to produce a composite field which is focused at a controllable distance below the surface of the specimen. The amplitude of the field reflected from this focus position is determined by the local reflection coefficient of the medium at the effective focal point. By processing the signals received for a range of ultrasonic transducer array focal lengths, the system can be used to locate and size anomalies within solids and liquids. Applications in both nondestructive evaluation and biomedical scanning are suggested.

  17. Design and simulation of an ultrasonic transducer

    NASA Astrophysics Data System (ADS)

    Yu, Zhenxian; Shi, Yanru; Hsu, Hung-Yao; Kong, Lingxue

    2005-12-01

    This paper presents a novel ultrasonic transducer which can be used as a liquid ejector to release drug. The ultrasonic transducer is based on the design of a flextensional transducer, which is composed of interdigital piezoelectric rings and a vibration membrane. The device works at an axisymmetric resonant mode to produce maximum amplitude at the center of the vibration membrane in axial direction. For the usage of multi piezoelectric rings, the flexural plate waves can be generated by applying two out-of-phase signals. The power consumption is of primary importance in the design of this device and the usage of single-ring or multi-ring piezoelectric material instead of bulk piezo material can therefore reduce the power consumption. An optimum working frequency, at which least power is required by the device, can be found by the piezoelectric, coupled field capability of the ANSYS/Multiphysics product.

  18. Transbronchial needle aspiration with a new electromagnetically-tracked TBNA needle

    NASA Astrophysics Data System (ADS)

    Choi, Jae; Popa, Teo; Gruionu, Lucian

    2009-02-01

    Transbronchial needle aspiration (TBNA) is a common method used to collect tissue for diagnosis of different chest diseases and for staging lung cancer, but the procedure has technical limitations. These limitations are mostly related to the difficulty of accurately placing the biopsy needles into the target mass. Currently, pulmonologists plan TBNA by examining a number of Computed Tomography (CT) scan slices before the operation. Then, they manipulate the bronchoscope down the respiratory track and blindly direct the biopsy. Thus, the biopsy success rate is low. The diagnostic yield of TBNA is approximately 70 percent. To enhance the accuracy of TBNA, we developed a TBNA needle with a tip position that can be electromagnetically tracked. The needle was used to estimate the bronchoscope's tip position and enable the creation of corresponding virtual bronchoscopic images from a preoperative CT scan. The TBNA needle was made with a flexible catheter embedding Wang Transbronchial Histology Needle and a sensor tracked by electromagnetic field generator. We used Aurora system for electromagnetic tracking. We also constructed an image-guided research prototype system incorporating the needle and providing a user-friendly interface to assist the pulmonologist in targeting lesions. To test the feasibility of the accuracy of the newly developed electromagnetically-tracked needle, a phantom study was conducted in the interventional suite at Georgetown University Hospital. Five TBNA simulations with a custom-made phantom with a bronchial tree were performed. The experimental results show that our device has potential to enhance the accuracy of TBNA.

  19. Incidence and severity of Arcanobacterium pyogenes injection site abscesses with needle or needle-free injection.

    PubMed

    Gerlach, Bryce M; Houser, Terry A; Hollis, Larry C; Tokach, Michael D; Nietfeld, Jerome C; Higgins, James J; Anderson, Gary A; Goehring, Brandon L

    2012-12-01

    Nursery-age pigs (n=198) were used to evaluate the difference in abscess formation at needle-free jet and conventional needle-and-syringe injection sites. Needle-free jet injection was used to administer injections in the neck and ham on one side of the animal whereas needle-and-syringe was used for neck and ham injections on the opposite side. Immediately prior to injection, the injection site surfaces were contaminated with an inoculum of Arcanobacterium pyogenes. Each pig was humanely euthanized 27 or 28 days after injections. Histopathological results showed that needle-free jet injection was associated with more abscesses than needle-and-syringe injection at both neck (P=0.0625) and ham (P=0.0313) injection sites. Out of 792 injection sites, only 13 abscesses were observed, with 12 of those present at needle-free jet injection sites. Needle-free jet injection may increase the occurrence of injection site abscesses that necessitate carcass trimming at pork processing plants. PMID:22854129

  20. Rapid prototyping fabrication of focused ultrasound transducers.

    PubMed

    Kim, Yohan; Maxwell, Adam D; Hall, Timothy L; Xu, Zhen; Lin, Kuang-Wei; Cain, Charles A

    2014-09-01

    Rapid prototyping (RP) fabrication techniques are currently widely used in diverse industrial and medical fields, providing substantial advantages in development time and costs in comparison to more traditional manufacturing processes. This paper presents a new method for the fabrication of high-intensity focused ultrasound transducers using RP technology. The construction of a large-aperture hemispherical transducer designed by computer software is described to demonstrate the process. The transducer was conceived as a modular design consisting of 32 individually focused 50.8-mm (2-in) PZT-8 element modules distributed in a 300-mm hemispherical scaffold with a geometric focus of 150 mm. The entire structure of the array, including the module housings and the hemispherical scaffold was fabricated through a stereolithography (SLA) system using a proprietary photopolymer. The PZT elements were bonded to the lenses through a quarter-wave tungsten-epoxy matching layer developed in-house specifically for this purpose. Modules constructed in this manner displayed a high degree of electroacoustic consistency, with an electrical impedance mean and standard deviation of 109 ± 10.2 Ω for the 32 elements. Time-of-flight measurements for individually pulsed modules mounted on the hemispherical scaffold showed that all pulses arrived at the focus within a 350 ns range, indicating a good degree of element alignment. Pressure profile measurements of the fully assembled transducer also showed close agreement with simulated results. The measured focal beam FWHM dimensions were 1.9 × 4.0 mm (1.9 × 3.9 mm simulated) in the transversal and axial directions respectively. Total material expenses associated with the construction of the transducer were approximately 5000 USD (as of 2011). The versatility and lower fabrication costs afforded by RP methods may be beneficial in the development of complex transducer geometries suitable for a variety of research and clinical applications

  1. Using XBee transducers for wireless data collection

    NASA Astrophysics Data System (ADS)

    Ayars, Eric; Lai, Estella

    2010-07-01

    This article describes how to use XBee transducers to create small and lightweight wireless sensors, which send data to a base station for collection and analysis. Data collection is limited to 10-bit accuracy by the XBee hardware. Depending on the type of XBee used, up to six data channels can be transmitted over a range of up to 15 miles. We describe the technical details of the process using the low-power version of the XBee transducer and a three-axis accelerometer chip.

  2. Ultrasonic transducer with laminated coupling wedge

    DOEpatents

    Karplus, Henry H. B.

    1976-08-03

    An ultrasonic transducer capable of use in a high-temperature environment incorporates a laminated metal coupling wedge including a reflecting edge shaped as a double sloping roof and a transducer crystal backed by a laminated metal sound absorber disposed so as to direct sound waves through the coupling wedge and into a work piece, reflections from the interface between the coupling wedge and the work piece passing to the reflecting edge. Preferably the angle of inclination of the two halves of the reflecting edge are different.

  3. Pressure transducer and system for cryogenic environments

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor)

    1992-01-01

    A silicon pressure die is bonded to a borosilicate substrate above the pneumatic port. A Wheatstone bridge circuit is formed on the silicon pressure die and has bridge elements of silicon doped with boron to a deposit density level of approximately 1 x 10(exp 19)-10(exp 21) boron/cc. A current source is provided to excite the Wheatstone bridge circuit. In addition, a temperature sensor is provided to provide temperature readings. An array may be formed of the resulting pressure transducers. This unique solution of materials permits operation of a pressure transducer in cryogenic environments.

  4. Mechano-electric optoisolator transducer with hysteresis

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  6. Optical Coherence Tomography in a Needle Format

    NASA Astrophysics Data System (ADS)

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

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

  7. Medically relevant ElectroNeedle technology development.

    SciTech Connect

    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.

  8. Focal Length Controllable Ultrasonic Array Transducer with Adjustable Curvature

    NASA Astrophysics Data System (ADS)

    Kim, Jungsoon; Kim, Moojoon; Ha, Kanglyel

    2012-07-01

    In the underwater imaging field, the control of the focal length of a transducer is very useful. As one of the control methods, we suggested an ultrasonic array transducer with adjustable curvature by using air pressure. The curvature of the transducer was investigated according to the air pressure level in the back space of the transducer. Concave-, planar-, and convex-type transducers were obtained with different air pressure levels. The acoustic fields of the transducer were measured for different shapes of the radiation surface.

  9. Transducer Joint for Kidney-Stone Ultrasonics

    NASA Technical Reports Server (NTRS)

    Angulo, E. D.

    1983-01-01

    Ultrasonic therapy for kidney stones improved by new way of connecting wire-probe ultrasonic waveguide to transducer. Improved mounting allows joint to last long enough for effective treatment. Sheath and rubber dampers constrain lateral vibration of wire waveguide. Combination of V-shaped mounting groove, sheath, and rubber dampers increases life expectancy of wire 15 times or more.

  10. Electropneumatic transducer automatically limits motor current

    NASA Technical Reports Server (NTRS)

    Lovitt, T. F.

    1966-01-01

    Pneumatic controller regulates the load on a centrifugal freon compressor in a water cooling system, thus limiting the current input to an electric motor driving it. An electromechanical transducer monitoring the motor input current sends out air signals which indicate changes in the current to the pneumatic controller.

  11. In sodium tests of ultrasonic transducers

    SciTech Connect

    Lhuillier, C.; Descombin, O.; Baque, F.; Marchand, B.; Saillant, J. F.

    2011-07-01

    Ultrasonic techniques are seen as suitable candidates for the in-service inspection and for the continuous surveillance of sodium cooled reactors (SFR). These techniques need the development and the qualification of immersed ultrasonic transducers, and materials. This paper presents some developments performed by CEA (DTN and LIST) and AREVA (NDE Solutions), and some results. (authors)

  12. Thermoacoustic power conversion using a piezoelectric transducer.

    PubMed

    Jensen, Carl; Raspet, Richard

    2010-07-01

    The predicted efficiency of a simple thermoacoustic waste heat power conversion device has been investigated as part of a collaborative effort combining a thermoacoustic engine with a piezoelectric transducer. Symko et al. [Microelectron. J. 35, 185-191 (2004)] at the University of Utah built high frequency demonstration engines for this application, and Lynn [ASMDC report, accession number ADA491030 (2008)] at the University of Washington designed and built a high efficiency piezoelectric unimorph transducer for electroacoustic conversion. The design presented in this paper is put forward to investigate the potential of a simple high frequency, air filled, standing wave thermoacoustic device to be competitive with other small generator technologies such as thermoelectric devices. The thermoacoustic generator is simulated using a low-amplitude approximation for thermoacoustics and the acoustic impedance of the transducer is modeled using an equivalent circuit model calculated from the transducer's mechanical and electrical properties. The calculations demonstrate that a device performance of around 10% of Carnot efficiency could be expected from the design which is competitive with currently available thermoelectric generators. PMID:20649205

  13. Ferroelectret non-contact ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    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. Improved Ultrasonic Transducer For Measuring Cryogenic Flow

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis

    1991-01-01

    Improved ultrasonic transducer used to measure flow of cryogenic fluid. Includes wedge made nonintrusive by machining it out of bulk material of duct carrying fluid. Skewed surfaces of wedge suppress standing waves, thus reducing ringing and increasing signal-to-noise ratio. Increases accuracy of measurements of times of arrival of ultrasonic pulses, from which times flow inferred.

  15. Broadband, High-Temperature Ultrasonic Transducer

    NASA Technical Reports Server (NTRS)

    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.

  16. Analysis of multifrequency langevin composite ultrasonic transducers.

    PubMed

    Lin, Shuyu

    2009-09-01

    The multimode coupled vibration of Langevin composite ultrasonic transducers with conical metal mass of large cross-section is analyzed. The coupled resonance and anti-resonance frequency equations are derived and the effective electromechanical coupling coefficient is analyzed. The effect of the geometrical dimensions on the resonance frequency, the anti-resonance frequency, and the effective electromechanical coupling coefficient is studied. It is illustrated that when the radial dimension is large compared with the longitudinal dimension, the vibration of the Langevin transducer becomes a multifrequency multimode coupled vibration. Numerical methods are used to simulate the coupled vibration; the simulated results are in good agreement with those from the analytical results. Some Langevin transducers of large cross-section are designed and manufactured and their resonance frequencies are measured. It can be seen that the resonance frequencies obtained from the coupled resonance frequency equations are in good agreement with the measured results. It is expected that by properly choosing the dimensions, multifrequency Langevin transducers can be designed and used in ultrasonic cleaning, ultrasonic sonochemistry, and other applications. PMID:19812002

  17. An IVUS Transducer for Microbubble Therapies

    PubMed Central

    Kilroy, Joseph P.; Patil, Abhay V.; Rychak, Joshua J.; Hossack, John A.

    2014-01-01

    There is interest in examining the potential of modified intravascular ultrasound (IVUS) catheters to facilitate dual diagnostic and therapeutic roles using ultrasound plus microbubbles for localized drug delivery to the vessel wall. The goal of this study was to design, prototype, and validate an IVUS transducer for microbubble-based drug delivery. A 1-D acoustic radiation force model and finite element analysis guided the design of a 1.5-MHz IVUS transducer. Using the IVUS transducer, biotinylated microbubbles were displaced in water and bovine whole blood to the streptavidin-coated wall of a flow phantom by a 1.5-MHz center frequency, peak negative pressure = 70 kPa pulse with varying pulse repetition frequency (PRF) while monitoring microbubble adhesion with ultrasound. A fit was applied to the RF data to extract a time constant (τ). As PRF was increased in water, the time constant decreased (τ = 32.6 s, 1 kHz vs. τ = 8.2 s, 6 kHz), whereas in bovine whole blood an adhesion–no adhesion transition was found for PRFs ≥ 8 kHz. Finally, a fluorophore was delivered to an ex vivo swine artery using microbubbles and the IVUS transducer, resulting in a 6.6-fold increase in fluorescence. These results indicate the importance of PRF (or duty factor) for IVUS acoustic radiation force microbubble displacement and the potential for IVUS and microbubbles to provide localized drug delivery. PMID:24569249

  18. Reliable, self-calibrating vibration transducer

    NASA Technical Reports Server (NTRS)

    Mc Kinney, R. L.

    1968-01-01

    Transducer system measures the uniaxial vibration amplitudes /deflections/ and frequency of a body subjected to mechanical vibration. The basic system is self-calibrating and provides an output which unambiguously indicates the direction as well as the magnitude of the uniaxial deflections.

  19. Attaching strain transducers to fragile materials

    NASA Technical Reports Server (NTRS)

    Duggan, M. F.

    1979-01-01

    A-shaped clamp prevents damage to thin, brittle specimens and supports displacement transducer away from heated zone. Also it defines reference points for strain measurement on specimen surface thus preventing specimen cracking due to unequal thermal expansion between clamp and holder.

  20. Myocardium wall thickness transducer and measuring method

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described.

  1. Non-bonded piezoelectric ultrasonic transducer

    DOEpatents

    Eoff, James M.

    1985-01-01

    A mechanically assembled non-bonded ultrasonic transducer includes a substrate, a piezoelectric film, a wetting agent, a thin metal electrode, and a lens held in intimate contact by a mechanical clamp. No epoxy or glue is used in the assembly of this device.

  2. Unified Technical Concepts. Module 10: Transducers.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This concept module on transducers is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each energy system.…

  3. Improved convergence of electromechanical transducer element

    NASA Astrophysics Data System (ADS)

    Sattler, Robert; Wachutka, Gerhard

    2002-04-01

    Electrostatic attraction is a favored principle of actuation in MEMS (e.g. mirrors, relays, membrane devices). In this work we use an electrostatically actuated membrane as demonstrator. Physically based device models require the coupling of the electrostatic and the two domains. One way to reduce this expense consists in reduced order modeling by introducing a local approximation of the electric field using the Differential-Plate-Capacitor-Approximation (DPCA). This semi-analytical approximation can be directly (matrix coupled transducer element) or sequentially (load vector coupling) coupled with the mechanical solver. Both approaches yield results which agree well with those of coupled 3D-field solvers. It turns out that the transducer element converges much faster than the sequentially coupled relaxation scheme, as ong as the voltage is not close to the pull-in voltage. If this is the case then the transducer element has problems to find the equilibrium state at all. To avoid this difficulty we propose the use of a homotopy method to give the transducer element the same accuracy and robustness in the stable and the unstable regions of the operating area. The electrostatic charge and the electrostatic force turn out to be proper homotopy parameters for the given example.

  4. Amperometric biosensors based on carbon composite transducers

    NASA Astrophysics Data System (ADS)

    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

  5. Evolvable Cryogenics (ECRYO) Pressure Transducer Calibration Test

    NASA Technical Reports Server (NTRS)

    Diaz, Carlos E., Jr.

    2015-01-01

    This paper provides a summary of the findings of recent activities conducted by Marshall Space Flight Center's (MSFC) In-Space Propulsion Branch and MSFC's Metrology and Calibration Lab to assess the performance of current "state of the art" pressure transducers for use in long duration storage and transfer of cryogenic propellants. A brief historical narrative in this paper describes the Evolvable Cryogenics program and the relevance of these activities to the program. This paper also provides a review of three separate test activities performed throughout this effort, including: (1) the calibration of several pressure transducer designs in a liquid nitrogen cryogenic environmental chamber, (2) the calibration of a pressure transducer in a liquid helium Dewar, and (3) the calibration of several pressure transducers at temperatures ranging from 20 to 70 degrees Kelvin (K) using a "cryostat" environmental chamber. These three separate test activities allowed for study of the sensors along a temperature range from 4 to 300 K. The combined data shows that both the slope and intercept of the sensor's calibration curve vary as a function of temperature. This homogeneous function is contrary to the linearly decreasing relationship assumed at the start of this investigation. Consequently, the data demonstrates the need for lookup tables to change the slope and intercept used by any data acquisition system. This ultimately would allow for more accurate pressure measurements at the desired temperature range. This paper concludes with a review of a request for information (RFI) survey conducted amongst different suppliers to determine the availability of current "state of the art" flight-qualified pressure transducers. The survey identifies requirements that are most difficult for the suppliers to meet, most notably the capability to validate the sensor's performance at temperatures below 70 K.

  6. Needle free injection technology: A complete insight.

    PubMed

    Ravi, Ansh Dev; Sadhna, D; Nagpaal, D; Chawla, L

    2015-01-01

    Needle free injection technology (NFIT)is an extremely broad concept which include a wide range of drug delivery systems that drive drugs through the skin using any of the forces as Lorentz, Shock waves, pressure by gas or electrophoresis which propels the drug through the skin, virtually nullifying the use of hypodermic needle. This technology is not only touted to be beneficial for the pharma industry but developing world too find it highly useful in mass immunization programmes, bypassing the chances of needle stick injuries and avoiding other complications including those arising due to multiple use of single needle. The NFIT devices can be classified based on their working, type of load, mechanism of drug delivery and site of delivery. To administer a stable, safe and an effective dose through NFIT, the sterility, shelf life and viscosity of drug are the main components which should be taken care of. Technically superior needle-free injection systems are able to administer highly viscous drug products which cannot be administered by traditional needle and syringe systems, further adding to the usefulness of the technology. NFIT devices can be manufactured in a variety of ways; however the widely employed procedure to manufacture it is by injection molding technique. There are many variants of this technology which are being marketed, such as Bioject(®) ZetaJetTM, Vitajet 3, Tev-Tropin(®) and so on. Larger investment has been made in developing this technology with several devices already being available in the market post FDA clearance and a great market worldwide. PMID:26682189

  7. Needle free injection technology: A complete insight

    PubMed Central

    Ravi, Ansh Dev; Sadhna, D; Nagpaal, D; Chawla, L

    2015-01-01

    Needle free injection technology (NFIT)is an extremely broad concept which include a wide range of drug delivery systems that drive drugs through the skin using any of the forces as Lorentz, Shock waves, pressure by gas or electrophoresis which propels the drug through the skin, virtually nullifying the use of hypodermic needle. This technology is not only touted to be beneficial for the pharma industry but developing world too find it highly useful in mass immunization programmes, bypassing the chances of needle stick injuries and avoiding other complications including those arising due to multiple use of single needle. The NFIT devices can be classified based on their working, type of load, mechanism of drug delivery and site of delivery. To administer a stable, safe and an effective dose through NFIT, the sterility, shelf life and viscosity of drug are the main components which should be taken care of. Technically superior needle-free injection systems are able to administer highly viscous drug products which cannot be administered by traditional needle and syringe systems, further adding to the usefulness of the technology. NFIT devices can be manufactured in a variety of ways; however the widely employed procedure to manufacture it is by injection molding technique. There are many variants of this technology which are being marketed, such as Bioject® ZetaJetTM, Vitajet 3, Tev-Tropin® and so on. Larger investment has been made in developing this technology with several devices already being available in the market post FDA clearance and a great market worldwide. PMID:26682189

  8. ["Sham Needle"--Design and Application of A Double-blind Placebo Needle Assembly].

    PubMed

    Yan, Liu; Ma, Li-hong

    2016-02-01

    The blind study design, particularly the double-blind study design is a very important method for diminishing placebo effect and reducing bias in clinical medical trial. Enlightened by Streitberger's and Park's sham needle design, the authors of the present paper introduce a newly designed sham needle device (Yan's sham-needle) for controlled double-blind trials of acupuncture. This sham needle device consists of needle, tube and base. The bottom of the tube is completely sealed and it can never arouse any invasive stimulation on the subject's skin when the sham needle is downward pressed on the body surface. Meanwhile, this sham device is filled with sponge which is able to simulate soft tissues of the acupoint area. By combining words suggestions or hints before trials and the same shape as verum device, this sham-needle device reduces the risk of blind-breaking and makes it possible to conduct controlled double-blind trials. Primary practice showed that this device may provide a new and practical tool for researching the placebo effect of acupuncture therapy. PMID:27141628

  9. Syringe and Needle Size, Syringe Type, Vacuum Generation, and Needle Control in Aspiration Procedures

    SciTech Connect

    Haseler, Luke J.; Sibbitt, Randy R.; Sibbitt, Wilmer L.; Michael, Adrian A.; Gasparovic, Charles M.; Bankhurst, Arthur D.

    2011-06-15

    Purpose: Syringes are used for diagnostic fluid aspiration and fine-needle aspiration biopsy in interventional procedures. We determined the benefits, disadvantages, and patient safety implications of syringe and needle size on vacuum generation, hand force requirements, biopsy/fluid yield, and needle control during aspiration procedures. Materials and Methods: Different sizes (1, 3, 5, 10, and 20 ml) of the conventional syringe and aspirating mechanical safety syringe, the reciprocating procedure device, were studied. Twenty operators performed aspiration procedures with the following outcomes measured: (1) vacuum (torr), (2) time to vacuum (s), (3) hand force to generate vacuum (torr-cm{sup 2}), (4) operator difficulty during aspiration, (5) biopsy yield (mg), and (6) operator control of the needle tip position (mm). Results: Vacuum increased tissue biopsy yield at all needle diameters (P < 0.002). Twenty-milliliter syringes achieved a vacuum of -517 torr but required far more strength to aspirate, and resulted in significant loss of needle control (P < 0.002). The 10-ml syringe generated only 15% less vacuum (-435 torr) than the 20-ml device and required much less hand strength. The mechanical syringe generated identical vacuum at all syringe sizes with less hand force (P < 0.002) and provided significantly enhanced needle control (P < 0.002). Conclusions: To optimize patient safety and control of the needle, and to maximize fluid and tissue yield during aspiration procedures, a two-handed technique and the smallest syringe size adequate for the procedure should be used. If precise needle control or one-handed operation is required, a mechanical safety syringe should be considered.

  10. PET-Based Percutaneous Needle Biopsy.

    PubMed

    El-Haddad, Ghassan

    2016-07-01

    PET can be used to guide percutaneous needle biopsy to the most metabolic lesion, improving diagnostic yield. PET biopsy guidance can be performed using visual or software coregistration, electromagnetic needle tracking, cone-beam computed tomography (CT), and intraprocedural PET/CT guidance. PET/CT-guided biopsies allow the sampling of lesions that may not be clearly visible on anatomic imaging, or of lesions that are morphologically normal. PET can identify suspicious locations within complex tumors that are most likely to contain important diagnostic and prognostic information. PMID:27321036

  11. Transducer technology transfer to bio-engineering applications. [aerospace stress transducer for heart function analysis

    NASA Technical Reports Server (NTRS)

    Duran, E. N.; Lewis, G. W.; Feldstein, C.; Corday, E.; Meerbaum, S.; Lang, T.

    1973-01-01

    The results of a technology transfer of a miniature unidirectional stress transducer, developed for experimental stress analysis in the aerospace field, to applications in bioengineering are reported. By modification of the basic design and innovations in attachment techniques, the transducer was successfully used in vivo on the myocardium of large dogs to record the change in contractile force due to coronary occlusion, reperfusion, and intervention.

  12. Mounting technique for pressure transducers minimizes measurement interferences

    NASA Technical Reports Server (NTRS)

    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.

  13. Pressure transducer system is force-balanced, has digital output

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Forced-balanced pressure transducer and associated circuitry controls pressure testing of space equipment systems under actual operating conditions. The transducer and circuitry automatically converts the sensed pressure to digital form.

  14. New type pressure transducer for severe thermal environments

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Pressure transducer used in a rocket motor chamber to measure the amplitudes and frequencies of dynamic pressures /exceeding 2000 psi/ occurring during unstable combustion. the transducer utilizes a transpirational cooled porous beryllium plug and pressure transmitting column.

  15. Transbronchial needle aspiration. An underused diagnostic technique.

    PubMed

    Dasgupta, A; Mehta, A C

    1999-03-01

    Despite its proven usefulness, TBNA is not widely used. An American College of Chest Physicians (ACCP) survey showed that only 11.8% of pulmonologists use TBNA. Most pulmonologists in the 1980s were not formally trained in TBNA. This lack of training has unfortunately translated to minimal emphasis on TBNA in current training programs in a large number of institutions. Technical problems with the procedure (faulty site selection, incomplete needle penetration, catheter kinking that prevents adequate suction, etc.), the confusing array of needles, low diagnostic yields, unproven concerns regarding the safety of the procedure, inadequate cytopathology support, and bronchoscopic damage have all perpetuated the image of limited usefulness for this procedure. Limitations to the practice of TBNA are: Lack of training during fellowship Technical inadequacies Lack of cytopathologists trained in TBNA interpretation Fear of bronchoscope damage Safety issues Failure to reproduce published successes Reservations regarding usefulness of TBNA results Hands-on experience with TBNA, developing familiarity and expertise with only a few needles, and paying careful attention to anatomy, procedure techniques, and specimen acquisition may all help to increase yield. The following lists how better results can be obtained with TBNA: Preprocedure Review TBNA instruction tapes Attend hands-on courses Practice with lung models Review patient's CAT scans Familiarize with one-two cytology and histology needle Obtain a trained assistant Procedural Identify target site Needle to airway angle at least greater than 45 degrees Insert entire length of the needle Use scope channel to support the catheter Release suction before withdrawing needle (for staging) Specimen acquisition Avoid delay in preparing slides Adequate sampling (at least two) Use smear method for cytology specimen Analyze all samples flush solutions cell block Postprocedure Find an experienced cytopathologist Review your procedure

  16. 41. VALVEHOUSE FOR NEEDLE VALVE OUTLET WORKS ON GALLERY 2, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. VALVEHOUSE FOR NEEDLE VALVE OUTLET WORKS ON GALLERY 2, SHOWING NEEDLE VALVE CONTROL PEDESTALS (MANUFACTURED BY AMERICAN LOCOMOTIVE COMPANY) IN LEFT FOREGROUND AND RIGHT BACKGROUND. VIEW TO NORTHEAST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  17. 21 CFR 890.1385 - Diagnostic electromyograph needle electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... needle electrode is a monopolar or bipolar needle intended to be inserted into muscle or nerve tissue to... electromyography (recording the intrinsic electrical properties of skeletal muscle). (b) Classification. Class...

  18. 21 CFR 890.1385 - Diagnostic electromyograph needle electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... needle electrode is a monopolar or bipolar needle intended to be inserted into muscle or nerve tissue to... electromyography (recording the intrinsic electrical properties of skeletal muscle). (b) Classification. Class...

  19. 21 CFR 890.1385 - Diagnostic electromyograph needle electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... needle electrode is a monopolar or bipolar needle intended to be inserted into muscle or nerve tissue to... electromyography (recording the intrinsic electrical properties of skeletal muscle). (b) Classification. Class...

  20. 21 CFR 890.1385 - Diagnostic electromyograph needle electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... needle electrode is a monopolar or bipolar needle intended to be inserted into muscle or nerve tissue to... electromyography (recording the intrinsic electrical properties of skeletal muscle). (b) Classification. Class...

  1. 21 CFR 890.1385 - Diagnostic electromyograph needle electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... needle electrode is a monopolar or bipolar needle intended to be inserted into muscle or nerve tissue to... electromyography (recording the intrinsic electrical properties of skeletal muscle). (b) Classification. Class...

  2. Length mode piezoelectric ultrasonic transducer for inspection of solid objects

    NASA Technical Reports Server (NTRS)

    Thompson, R. B. (Inventor)

    1978-01-01

    The transducer is constructed from individual transducer elements arranged in an array and configured to exhibit a predominant, longitudinal mode transversely to the array. The elements are interconnected through thin flexible sheets. Each element is individually damped, and the transducer as a whole is electrically damped through resonance with the clamped capacitance and dissipation. Electrical control permits inphase operation of all transducer elements or control with preselected phase differences.

  3. Signal processing schemes for optical voltage transducer

    NASA Astrophysics Data System (ADS)

    Chen, Jinling; Xie, Delin; Chen, Hongbin; Xie, Latang; Song, Jianhe; Luo, Xiaoni

    2006-02-01

    This paper describes an optical voltage transducer(OVT) for a 35kV system based on Pockels effect in a BGO(Bi 4Ge 3O 12) crystal. OVT used to measure the voltage of power are superior to conventional electromagnet-induced voltage transducer in many aspects, thus it has great potential to applications. It has some advantages. These advantages are: 1)Optics provides total galvanic separation between the measuring point at high voltage (HV) potential and the measuring equipment at ground potential. 2)Transmission of measuring signals in optical fibers is immune to induced electromagnetic noise even in EMI-environment of switchyards and other high voltage installations. 3)Optics and especially optical fibers make the insulation costs independent of voltage levels thus giving an economical advantage at voltage levels above 100kV. 4)The use of optics is expected to reduce the weight of the transducers. 5)Optical transducers are expected to have a large bandwidth than conventional transducers. 6)The output-signals from an optical transducer are easily interfaced with computers and electronically operated equipment such as digital relays. New techniques developed in electronics and optical field including fiber optic technology bring new contributions to the measurement of voltage and electric field. A Pockels voltage sensor has been widely introduced to electrical power transmission and distribution systems and some advantage of the optical voltage measuring techniques are reported. In this paper, a brief summary of electro-optic effects and the principle of OVT is proposed. The signal processing schemes of different optical path and features are analyzed. The basic principle of OVT is to modulate the irradiance of the light-directed to OVT by an optical fiber-according to the potential difference between the HV-line and the ground potential. The modulation of the light is accomplished by placing a material-that has an optical property (the birefringence), which is

  4. 21 CFR 868.2885 - Gas flow transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Gas flow transducer. 868.2885 Section 868.2885...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2885 Gas flow transducer. (a) Identification. A gas flow transducer is a device intended for medical purposes that is used to convert gas...

  5. 21 CFR 868.2885 - Gas flow transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Gas flow transducer. 868.2885 Section 868.2885...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2885 Gas flow transducer. (a) Identification. A gas flow transducer is a device intended for medical purposes that is used to convert gas...

  6. 21 CFR 868.2885 - Gas flow transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Gas flow transducer. 868.2885 Section 868.2885...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2885 Gas flow transducer. (a) Identification. A gas flow transducer is a device intended for medical purposes that is used to convert gas...

  7. 21 CFR 868.2885 - Gas flow transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gas flow transducer. 868.2885 Section 868.2885...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2885 Gas flow transducer. (a) Identification. A gas flow transducer is a device intended for medical purposes that is used to convert gas...

  8. 21 CFR 868.2885 - Gas flow transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Gas flow transducer. 868.2885 Section 868.2885 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2885 Gas flow transducer. (a) Identification. A gas flow transducer is a device intended...

  9. 21 CFR 868.2900 - Gas pressure transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gas pressure transducer. 868.2900 Section 868.2900...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2900 Gas pressure transducer. (a) Identification. A gas pressure transducer is a device intended for medical purposes that is used to convert...

  10. 21 CFR 870.2870 - Catheter tip pressure transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Catheter tip pressure transducer. 870.2870 Section... pressure transducer. (a) Identification. A catheter tip pressure transducer is a device incorporated into... change in relation to changes in blood pressure. These changes are transmitted to accessory equipment...

  11. 21 CFR 868.2875 - Differential pressure transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Differential pressure transducer. 868.2875 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2875 Differential pressure transducer. (a) Identification. A differential pressure transducer is a two-chambered device intended...

  12. 21 CFR 868.2900 - Gas pressure transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Gas pressure transducer. 868.2900 Section 868.2900...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2900 Gas pressure transducer. (a) Identification. A gas pressure transducer is a device intended for medical purposes that is used to convert...

  13. 21 CFR 868.2900 - Gas pressure transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Gas pressure transducer. 868.2900 Section 868.2900...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2900 Gas pressure transducer. (a) Identification. A gas pressure transducer is a device intended for medical purposes that is used to convert...

  14. 21 CFR 868.2875 - Differential pressure transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Differential pressure transducer. 868.2875 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2875 Differential pressure transducer. (a) Identification. A differential pressure transducer is a two-chambered device intended...

  15. 21 CFR 870.2870 - Catheter tip pressure transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Catheter tip pressure transducer. 870.2870 Section... pressure transducer. (a) Identification. A catheter tip pressure transducer is a device incorporated into... change in relation to changes in blood pressure. These changes are transmitted to accessory equipment...

  16. 21 CFR 870.2870 - Catheter tip pressure transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Catheter tip pressure transducer. 870.2870 Section... pressure transducer. (a) Identification. A catheter tip pressure transducer is a device incorporated into... change in relation to changes in blood pressure. These changes are transmitted to accessory equipment...

  17. 21 CFR 868.2900 - Gas pressure transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Gas pressure transducer. 868.2900 Section 868.2900...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2900 Gas pressure transducer. (a) Identification. A gas pressure transducer is a device intended for medical purposes that is used to convert...

  18. 21 CFR 868.2875 - Differential pressure transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Differential pressure transducer. 868.2875 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2875 Differential pressure transducer. (a) Identification. A differential pressure transducer is a two-chambered device intended...

  19. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Transducer signal amplifier and conditioner. 870.2060 Section 870.2060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier...

  20. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Transducer signal amplifier and conditioner. 870.2060 Section 870.2060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier...

  1. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Transducer signal amplifier and conditioner. 870.2060 Section 870.2060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier...

  2. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Transducer signal amplifier and conditioner. 870.2060 Section 870.2060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier...

  3. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transducer signal amplifier and conditioner. 870.2060 Section 870.2060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier...

  4. 21 CFR 870.2850 - Extravascular blood pressure transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Extravascular blood pressure transducer. 870.2850... blood pressure transducer. (a) Identification. An extravascular blood pressure transducer is a device used to measure blood pressure by changes in the mechanical or electrical properties of the device....

  5. 21 CFR 870.2850 - Extravascular blood pressure transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Extravascular blood pressure transducer. 870.2850... blood pressure transducer. (a) Identification. An extravascular blood pressure transducer is a device used to measure blood pressure by changes in the mechanical or electrical properties of the device....

  6. 21 CFR 870.2850 - Extravascular blood pressure transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Extravascular blood pressure transducer. 870.2850... blood pressure transducer. (a) Identification. An extravascular blood pressure transducer is a device used to measure blood pressure by changes in the mechanical or electrical properties of the device....

  7. 21 CFR 870.2850 - Extravascular blood pressure transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Extravascular blood pressure transducer. 870.2850... blood pressure transducer. (a) Identification. An extravascular blood pressure transducer is a device used to measure blood pressure by changes in the mechanical or electrical properties of the device....

  8. 21 CFR 870.2850 - Extravascular blood pressure transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Extravascular blood pressure transducer. 870.2850... blood pressure transducer. (a) Identification. An extravascular blood pressure transducer is a device used to measure blood pressure by changes in the mechanical or electrical properties of the device....

  9. 21 CFR 870.2870 - Catheter tip pressure transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... change in relation to changes in blood pressure. These changes are transmitted to accessory equipment for... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Catheter tip pressure transducer. 870.2870 Section... pressure transducer. (a) Identification. A catheter tip pressure transducer is a device incorporated...

  10. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Obstetric ultrasonic transducer and accessories... Monitoring Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to apply ultrasonic energy to, and to receive...

  11. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Obstetric ultrasonic transducer and accessories... Monitoring Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to apply ultrasonic energy to, and to receive...

  12. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Obstetric ultrasonic transducer and accessories... Monitoring Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to apply ultrasonic energy to, and to receive...

  13. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Obstetric ultrasonic transducer and accessories... Monitoring Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to apply ultrasonic energy to, and to receive...

  14. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Obstetric ultrasonic transducer and accessories... Monitoring Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to apply ultrasonic energy to, and to receive...

  15. 21 CFR 892.1570 - Diagnostic ultrasonic transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Diagnostic ultrasonic transducer. 892.1570 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1570 Diagnostic ultrasonic transducer. (a) Identification. A diagnostic ultrasonic transducer is a device made of a piezoelectric...

  16. A Modification to Maxwell's Needle Apparatus

    ERIC Educational Resources Information Center

    Soorya, Tribhuvan N.

    2015-01-01

    Maxwell's needle apparatus is used to determine the shear modulus (?) of the material of a wire of uniform cylindrical cross section. Conventionally, a single observation is taken for each observable, and the value of ? is calculated in a single shot. A modification to the above apparatus is made by varying one of the observables, namely the mass…

  17. The Single Needle Lockstitch Machine. Module 1.

    ERIC Educational Resources Information Center

    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…

  18. Thin needle aspiration biopsy of endocrine organs.

    PubMed

    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

  19. Genetics Home Reference: Melnick-Needles syndrome

    MedlinePlus

    ... or buccal smear. Am J Med Genet. 2002 Mar 1;108(2):120-7. Citation on PubMed OMIM: ... 2003 Apr;33(4):487-91. Epub 2003 Mar 3. Citation on ... syndrome types 1 and 2, frontometaphyseal dysplasia and Melnick-Needles syndrome. ...

  20. Particulate contamination of sterile syringes and needles.

    PubMed

    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

  1. Three-Dimensional Sonography With Needle Tracking

    PubMed Central

    Shen, Feimo; Shinohara, Katsuto; Kumar, Dinesh; Khemka, Animesh; Simoneau, Anne R.; Werahera, Priya N.; Li, Lu; Guo, Yujun; Narayanan, Ramkrishnan; Wei, Liyang; Al Barqawi; Crawford, E. David; Davatzikos, Christos; Suri, Jasjit S.

    2012-01-01

    Objective Image-guided prostate biopsy has become routine in medical diagnosis. Although it improves biopsy outcome, it mostly operates in 2 dimensions, therefore lacking presentation of information in the complete 3-dimensional (3D) space. Because prostatic carcinomas are nonuniformly distributed within the prostate gland, it is crucial to accurately guide the needles toward clinically important locations within the 3D volume for both diagnosis and treatment. Methods We reviewed the uses of 3D image-guided needle procedures in prostate cancer diagnosis and cancer therapy as well as their advantages, work flow, and future directions. Results Guided procedures for the prostate rely on accurate 3D target identification and needle navigation. This 3D approach has potential for better disease diagnosis and therapy. Additionally, when fusing together different imaging modalities and cancer probability maps obtained from a population of interest, physicians can potentially place biopsy needles and other interventional devices more accurately and efficiently by better targeting regions that are likely to host cancerous tissue. Conclusions With the information from anatomic, metabolic, functional, biochemical, and biomechanical statuses of different regions of the entire gland, prostate cancers will be better diagnosed and treated with improved work flow. PMID:18499849

  2. The Double-Needle Felling Machine. Module 17.

    ERIC Educational Resources Information Center

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

    This module on the double-needle felling machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers two topics: performing special operations on the double-needle felling machine (straight seams) and performing special operations on the double-needle felling machine (curved flat-felled seams). For…

  3. Hollow needle used to cut metal honeycomb structures

    NASA Technical Reports Server (NTRS)

    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.

  4. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  5. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  6. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  7. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  8. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  9. 21 CFR 872.4730 - Dental injecting needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental injecting needle. 872.4730 Section 872.4730...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4730 Dental injecting needle. (a) Identification. A dental injecting needle is a slender, hollow metal device with a sharp point intended to be attached to...

  10. 21 CFR 872.4730 - Dental injecting needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental injecting needle. 872.4730 Section 872.4730...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4730 Dental injecting needle. (a) Identification. A dental injecting needle is a slender, hollow metal device with a sharp point intended to be attached to...

  11. 21 CFR 872.4730 - Dental injecting needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental injecting needle. 872.4730 Section 872.4730...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4730 Dental injecting needle. (a) Identification. A dental injecting needle is a slender, hollow metal device with a sharp point intended to be attached to...

  12. 21 CFR 872.4730 - Dental injecting needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental injecting needle. 872.4730 Section 872.4730...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4730 Dental injecting needle. (a) Identification. A dental injecting needle is a slender, hollow metal device with a sharp point intended to be attached to...

  13. 21 CFR 872.4730 - Dental injecting needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental injecting needle. 872.4730 Section 872.4730...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4730 Dental injecting needle. (a) Identification. A dental injecting needle is a slender, hollow metal device with a sharp point intended to be attached to...

  14. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  15. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  16. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  17. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  18. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  19. Modeling and Control of Needles with Torsional Friction

    PubMed Central

    Reed, Kyle B.; Okamura, Allison M.; Cowan, Noah J.

    2010-01-01

    A flexible needle can be accurately steered by robotically controlling the bevel tip orientation as the needle is inserted into tissue. Friction between the long, flexible needle shaft and the tissue can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle angle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial friction forces to the needle shaft, resulting in a lag of over 45° for a 10 cm insertion depth in some phantoms; clinical studies report torques large enough to cause similar errors during needle insertions. Such angle discrepancies will result in poor performance or failure of path planners and image-guided controllers, since the needles used in percutaneous procedures are too small for state-of-the-art imaging to accurately measure the tip angle. To compensate for the angle discrepancy, we develop an estimator using a mechanics-based model of the rotational dynamics of a needle being inserted into tissue. Compared to controllers that assume a rigid needle in a frictionless environment, our estimator-based controller improves the tip angle convergence time by nearly 50% and reduces the path deviation of the needle by 70%. PMID:19695979

  20. Modeling and control of needles with torsional friction.

    PubMed

    Reed, Kyle B; Okamura, Allison M; Cowan, Noah J

    2009-12-01

    A flexible needle can be accurately steered by robotically controlling the bevel tip orientation as the needle is inserted into tissue. Friction between the long, flexible needle shaft and the tissue can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle angle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial friction forces to the needle shaft, resulting in a lag of more than 45 ( degrees ) for a 10 cm insertion depth in some phantoms; clinical studies report torques large enough to cause similar errors during needle insertions. Such angle discrepancies will result in poor performance or failure of path planners and image-guided controllers, since the needles used in percutaneous procedures are too small for state-of-the-art imaging to accurately measure the tip angle. To compensate for the angle discrepancy, we develop an estimator using a mechanics-based model of the rotational dynamics of a needle being inserted into tissue. Compared to controllers that assume a rigid needle in a frictionless environment, our estimator-based controller improves the tip angle convergence time by nearly 50% and reduces the path deviation of the needle by 70%. PMID:19695979

  1. Electromechanical transducer for acoustic telemetry system

    DOEpatents

    Drumheller, Douglas S.

    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.

  2. Bonded ultrasonic transducer and method for making

    DOEpatents

    Dixon, R.D.; Roe, L.H.; Migliori, A.

    1995-11-14

    An ultrasonic transducer is formed as a diffusion bonded assembly of piezoelectric crystal, backing material, and, optionally, a ceramic wear surface. The mating surfaces of each component are silver films that are diffusion bonded together under the application of pressure and heat. Each mating surface may also be coated with a reactive metal, such as hafnium, to increase the adhesion of the silver films to the component surfaces. Only thin silver films are deposited, e.g., a thickness of about 0.00635 mm, to form a substantially non-compliant bond between surfaces. The resulting transducer assembly is substantially free of self-resonances over normal operating ranges for taking resonant ultrasound measurements. 12 figs.

  3. Bonded ultrasonic transducer and method for making

    DOEpatents

    Dixon, Raymond D.; Roe, Lawrence H.; Migliori, Albert

    1995-01-01

    An ultrasonic transducer is formed as a diffusion bonded assembly of piezoelectric crystal, backing material, and, optionally, a ceramic wear surface. The mating surfaces of each component are silver films that are diffusion bonded together under the application of pressure and heat. Each mating surface may also be coated with a reactive metal, such as hafnium, to increase the adhesion of the silver films to the component surfaces. Only thin silver films are deposited, e.g., a thickness of about 0.00635 mm, to form a substantially non-compliant bond between surfaces. The resulting transducer assembly is substantially free of self-resonances over normal operating ranges for taking resonant ultrasound measurements.

  4. Acoustic transducer apparatus with reduced thermal conduction

    NASA Technical Reports Server (NTRS)

    Lierke, Ernst G. (Inventor); Leung, Emily W. (Inventor); Bhat, Balakrishna T. (Inventor)

    1990-01-01

    A horn is described for transmitting sound from a transducer to a heated chamber containing an object which is levitated by acoustic energy while it is heated to a molten state, which minimizes heat transfer to thereby minimize heating of the transducer, minimize temperature variation in the chamber, and minimize loss of heat from the chamber. The forward portion of the horn, which is the portion closest to the chamber, has holes that reduce its cross-sectional area to minimize the conduction of heat along the length of the horn, with the entire front portion of the horn being rigid and having an even front face to efficiently transfer high frequency acoustic energy to fluid in the chamber. In one arrangement, the horn has numerous rows of holes extending perpendicular to the length of horn, with alternate rows extending perpendicular to one another to form a sinuous path for the conduction of heat along the length of the horn.

  5. Electromechanical transducer for acoustic telemetry system

    DOEpatents

    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.

  6. Gel-Filled Holders For Ultrasonic Transducers

    NASA Technical Reports Server (NTRS)

    Companion, John A.

    1992-01-01

    In new technique, ultrasonic transducer embedded in rubbery, castable, low-loss gel to enable transducer to "look" into surface of test object or human body at any desired angle. Composed of solution of water and ethylene glycol in collagen matrix. Provides total contact of water bath, also used on bodies or objects too large for water baths, even if moving. Also provides look angles of poly(methyl methacrylate) angle block with potential of reduced acoustic impedance and refraction. Custom-tailored to task at hand, and gel sufficiently inexpensive to be discarded upon completion. Easy to couple ultrasound in and out of gel, minimizing losses and artifacts of other types of standoffs employed in ultrasonic testing.

  7. Acupuncture sensation during ultrasound guided acupuncture needling

    PubMed Central

    Park, Jongbae J.; Akazawa, Margeaux; Ahn, Jaeki; Beckman-Harned, Selena; Lin, Feng-Chang; Lee, Kwangjae; Fine, Jason; Davis, Robert T; Langevin, Helene

    2014-01-01

    Background Although acupuncture sensation (also known as de qi) is a cornerstone of traditional acupuncture therapy, most research has accepted the traditional method of defining acupuncture sensation only through subjective patient reports rather than on any quantifiable physiological basis. Purpose To preliminarily investigate the frequency of key sensations experienced while needling to specific, quantifiable tissue levels (TLs) guided by ultrasound (US) imaging. Methods Five participants received needling at two acupuncture points and two control points at four TLs. US scans were used to determine when each TL was reached. Each volunteer completed 32 sets of modified Southampton Needle Sensation Questionnaires. Part one of the study tested sensations experienced at each TL and part two compared the effect of oscillation alone versus oscillation + rotation. Results In all volunteers, the frequency of pricking, sharp sensations was significantly greater in shallower TLs than deeper (p=0.007); the frequency of sensations described as deep, dull and heavy, as spreading, and as electric shocks was significantly greater in deeper TLs than shallower (p=0.002). Sensations experienced did not significantly differ between real and control points within each of three TLs (p>0.05) except TL 4 (p=0.006). The introduction of needle rotation significantly increased deep, dull, heavy sensations, but not pricking and sharp sensations; within each level, the spectrum of sensation experienced during both oscillation + rotation and oscillation alone did not significantly differ between acupuncture and control points. Conclusion The preliminary study indicates a strong connection between acupuncture sensation and both tissue depth and needle rotation. Furthermore, the new methodology has been proven feasible. A further study with an objective measurement is warranted. PMID:21642648

  8. Flutter spectral measurements using stationary pressure transducers

    NASA Technical Reports Server (NTRS)

    Kurkov, A. P.

    1980-01-01

    Engine-order sampling was used to eliminate the integral harmonics from the flutter spectra corresponding to a case-mounted static pressure transducer. Using the optical displacement data, it was demonstrated that the blade-order sampling of pressure data may yield erroneous results due to the interference caused by blade vibration. Two methods are presented which effectively eliminate this interference yielding the blade-pressure-difference spectra. The phase difference between the differential-pressure and the displacement spectra was evaluated.

  9. Robust Acoustic Transducers for Bubble Chambers

    NASA Astrophysics Data System (ADS)

    Wells, Jonathan

    2015-04-01

    The PICO collaboration utilizes bubble chambers filled with various superheated liquids as targets for dark matter. Acoustic sensors have proved able to distinguish nuclear recoils from radioactive background on an event-by-event basis. We have recently produced a more robust transducer which should be able to operate for years, rather than months, in the challenging environment of a heated high pressure hydraulic fluid outside these chambers. Indiana University South Bend.

  10. Ultrasonic transducer with Gaussian radial pressure distribution

    NASA Technical Reports Server (NTRS)

    Claus, R. O.; Zerwekh, P. S. (Inventor)

    1984-01-01

    An ultrasonic transducer that produces an output that is a symmetrical function comprises a piezoelectric crystal with several concentric ring electrodes on one side of the crystal. A resistor network applies different amplitudes of an ac source to each of the several electrodes. A plot of the different amplitudes from the outermost electrode to the innermost electrode is the first half of a Gaussian function. Consequently, the output of the crystal from the side opposite the electrodes has a Gaussian profile.

  11. Modeling a magnetostrictive transducer using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Almeida, L. A. L.; Deep, G. S.; Lima, A. M. N.; Neff, H.

    2001-05-01

    This work reports on the applicability of the genetic algorithm (GA) to the problem of parameter determination of magnetostrictive transducers. A combination of the Jiles-Atherton hysteresis model with a quadratic moment rotation model is simulated using known parameters of a sensor. The simulated sensor data are then used as input data for the GA parameter calculation method. Taking the previously known parameters, the accuracy of the GA parameter calculation method can be evaluated.

  12. Characterization of transducer cavities to oscillatory inputs

    SciTech Connect

    Rogers, J.D.; Hollingshead, J.R.

    1993-12-31

    The design and use of measurement systems must ensure that the data are not computed by the measurement system. A wide variety of sources can be responsible for compromising the integrity of test data. Among the sources of error are transducer calibration errors, signal conditioning problems, recording problems, and characteristics of the mechanical system which introduce errors. In this paper, the characteristics of an acoustic cavity are discussed as they apply to a pressure measurement problem.

  13. "Zero-Mass" Noninvasive Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2009-01-01

    Extremely lightweight, compact, noninvasive, rugged, relatively inexpensive strain-gauge transducers have been developed for use in measuring pressures of fluids in tubes. These gauges were originally intended for measuring pressures of spacecraft-propulsion fluids, but they are also attractive for use in numerous terrestrial applications especially those involving fluids that are extremely chemically reactive, fluids that must be isolated for hygienic purposes, fluids that must be allowed to flow without obstruction, and fluid-containing tubes exposed to severe environments. A basic pressure transducer of this type comprises one or more pair(s) of thin-film strain gauges integral with a tube that contains the fluid of interest. Following established strain-gauge practice, the gauges in each pair are connected into opposite arms of a Wheatstone bridge (see figure). Typically, each pressure transducer includes one pair (the active pair) of strain gauges for measuring the hoop stress proportional to the pressure of the fluid in the tube and another pair (the dummy pair) of strain gauges that are nominally unstrained: The dummy gauges are mounted on a substrate that is made of the same material as that of the tube. The substrate is welded to the tube at only one spot so that stresses and strains are not coupled from the tube into the substrate. The dummy strain gauges measure neutral strains (basically, strains associated with thermal expansion), so that the neutral-strain contribution can be subtracted out of the final gauge reading.

  14. Marine transducing bacteriophage attacking a luminous bacterium.

    PubMed

    Keynan, A; Nealson, K; Sideropoulos, H; Hastings, J W

    1974-08-01

    The isolation and partial characterization of a marine bacteriophage attacking a strain of luminous bacteria is described, including some physical, biological, and genetic properties. It is a DNA phage of density of 1.52 with a long flexible tail and an apparently icosohedral head. With respect to stability in suspension, it has a rather specific requirement for the sodium ion in high concentration; it is further stabilized by the addition of calcium and magnesium ions. These same ions are likewise all required for both good plating efficiency and plaque uniformity. Although it goes through a typical lytic growth cycle (about 45 min), with a burst size of 100, and no stable lysogens have been isolated, it is nevertheless a transducing phage specifically for the tryptophan region, transducing several, but not all, independently isolated Trp(-) auxotrophs to protrophy. No other auxotrophs of a variety of amino acids were transduced by this phage to prototrophy. Phage infection does not change the normal expression of the luminescent system, and light remains at near normal levels until cell lysis occurs. PMID:16789143

  15. Simultaneous muscle force and displacement transducer

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Culler, V. H. (Inventor)

    1980-01-01

    A myocardial transducer for simultaneously measuring force and displacement within a very small area of myocardium is disclosed. The transducer comprised of an elongated body forked at one end to form an inverted Y shaped beam with each branch of the beam constituting a low compliant tine for penetrating the myocardium to a predetermined depth. Bonded to one of the low compliance tines is a small piezoresistive element for converting a force acting on the beam into an electrical signal. A third high compliant tine of the transducer, which measures displacement of the myocardium in a direction in line with the two low compliant tines, is of a length that just pierces the surface membrane. A small piezoresistive element is bonded to the third tine at its upper end where its bending is greatest. Displacement of the myocardium causes a deformation in curvature of the third tine, and the second small piezoresistive element bonded to the surface of its curved end converts its deformation into an electrical signal.

  16. Sector array transducers for vibro-acoustography

    NASA Astrophysics Data System (ADS)

    Silva, Glauber; Chen, Shigao; Kinnick, Randall; Greenleaf, James; Fatemi, Mostafa

    2003-10-01

    Vibro-acoustography is an imaging technique that maps the acoustic response of an object to a localized harmonic radiation force. This force is generated by two interfering continuous-wave ultrasound beams at slightly different frequencies f1 and f2. The system point-spread function (PSF) is related to the radiation force on a point-target. Imaging artifacts depend on the PSF sidelobes, which can be reduced by mismatching the sidelobes of each ultrasound beam. Here, we propose a beamforming approach based on an 8-element sector transducer with consecutive elements alternately driven at f1 and f2. The transducer generates two ultrasound beams skewed by 22.5° with respect to each other. The system PSF is analytically derived. The theory is validated by experiments using a small steel sphere (radius =0.2 mm) as a point-target. A laser vibrometer is used to measure the vibration of the sphere and evaluate the PSF of the system. Theoretically, the PSF sidelobes are under -15.8 dB in eight spots circularly distributed and separated by 22.5°, which agrees with the experimental results. Simulation shows that with 16 elements sidelobes are under -35.2 dB. In conclusion, sector transducers for vibro-acoustography may have lower sidelobes as the number of array elements is increased. [Work supported by Grant Nos. EB00535-01, EB2640, and IMG0100744.

  17. Cross-fiber Bragg grating transducer

    NASA Technical Reports Server (NTRS)

    Albin, Sacharia (Inventor); Zheng, Jianli (Inventor); Lavarias, Arnel (Inventor)

    2000-01-01

    A transducer has been invented that uses specially-oriented gratings in waveguide a manner that allows the simultaneous measurement of physical phenomena (such as shear force, strain and temperature) in a single sensing element. The invention has a highly sensitive, linear response and also has directional sensitivity with regard to strain. The transducer has a waveguide with a longitudinal axis as well as two Bragg gratings. The transducer has a first Bragg grating associated with the waveguide that has an angular orientation .theta..sub.a relative to a perpendicular to the longitudinal axis such that 0.degree.<.theta..sub.a <.theta..sub.max. The second Bragg grating is associated with the waveguide in such a way that the angular orientation .theta..sub.b of the grating relative to a perpendicular to the longitudinal axis is (360.degree.-.theta..sub.max)<.theta..sub.b <360.degree.. The first Bragg grating can have a periodicity .LAMBDA..sub.a and the second Bragg grating can have a periodicity .LAMBDA..sub.b such that the periodicity .LAMBDA..sub.a of the first Bragg grating does not equal the periodicity .LAMBDA..sub.b of the second Bragg grating. The angle of the gratings can be such that .theta..sub.a =360.degree.-.theta..sub.b. The waveguide can assume a variety of configurations, including an optical fiber, a rectangular waveguide and a planar waveguide. The waveguide can be fabricated of a variety of materials, including silica and polymer material.

  18. Macroscopic and microscopic observations of needle insertion into gels.

    PubMed

    van Veen, Youri R J; Jahya, Alex; Misra, Sarthak

    2012-06-01

    Needle insertion into soft tissue is one of the most common medical interventions. This study provides macroscopic and microscopic observations of needle-gel interactions. A gelatin mixture is used as a soft-tissue simulant. For the macroscopic studies, system parameters, such as insertion velocity, needle diameter, gel elasticity, needle tip shape (including bevel angle) and insertion motion profile, are varied, while the maximum insertion force and maximum needle deflection are recorded. The needle tip and gel interactions are observed using confocal microscopic images. Observations indicate that increasing the insertion velocity and needle diameter results in larger insertion forces and smaller needle deflections. Varying the needle bevel angle from 8 degrees to 82 degrees results in the insertion force increasing monotonically, while the needle deflection does not. These variations are due to the coupling between gel rupture and tip compression interactions, which are observed during microscopic studies. Increasing the gel elasticity results in larger insertion forces and needle deflections. Varying the tip shapes demonstrates that bevel-tipped needles produce the largest deflection, but insertion force does not vary among the tested tip shapes. Insertion with different motion profiles are performed. Results show that adding I Hz rotational motion during linear insertion decreases the needle deflection. Increasing the rotational motion from I Hz to 5 Hz decreases the insertion force, while the needle deflection remains the same. A high-velocity (250 mm/s and 300 mm/s) tapping during insertion yields no significant decrease in needle deflection and a slight increase in insertion force. PMID:22783760

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

    PubMed

    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

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

    PubMed Central

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

    2013-01-01

    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. PMID:23814408

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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. Dual mode fuel injector with one piece needle valve member

    DOEpatents

    Lawrence, Keith E.; Hinrichsen, Michael H.; Buckman, Colby

    2005-01-18

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively by inner and outer needle value members. The homogenous charged nozzle outlet set is defined by an outer needle value member that is moveably positioned in an injector body, which defines the conventional nozzle outlet set. The inner needle valve member is positioned in the outer needle valve member. The outer needle valve member is a piece component that includes at least one external guide surface, an external value surface and an internal valve seat.

  4. Kinematics Analysis of an Aided Robot for Needle Insertion

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Gao, Dedong; Wang, Shan; Bai, Huiquan; Zheng, Haojun

    The kinematic relationship between the needle base and the robot's joints is analyzed. The analysis process is based on the aided needle-insertion robot built by our group. The thinking of needle-inserting procedure is confirming the needle base's posture before the needle inserted into tissue. The method of Denavit-Hartenberg (D-H) parameters is used to establish a link robot body-frames with the structural characteristics of the robot. After analysing kinematics, the kinematics equation is presented. The kinematics inverse solutions are obtained with the analytical method and geometry analysis method.

  5. New Methods and Transducer Designs for Ultrasonic Diagnostics and Therapy

    NASA Astrophysics Data System (ADS)

    Rybyanets, A. N.; Naumenko, A. A.; Sapozhnikov, O. A.; Khokhlova, V. A.

    Recent advances in the field of physical acoustics, imaging technologies, piezoelectric materials, and ultrasonic transducer design have led to emerging of novel methods and apparatus for ultrasonic diagnostics, therapy and body aesthetics. The paper presents the results on development and experimental study of different high intensity focused ultrasound (HIFU) transducers. Technological peculiarities of the HIFU transducer design as well as theoretical and numerical models of such transducers and the corresponding HIFU fields are discussed. Several HIFU transducers of different design have been fabricated using different advanced piezoelectric materials. Acoustic field measurements for those transducers have been performed using a calibrated fiber optic hydrophone and an ultrasonic measurement system (UMS). The results of ex vivo experiments with different tissues as well as in vivo experiments with blood vessels are presented that prove the efficacy, safety and selectivity of the developed HIFU transducers and methods.

  6. Environmental control system transducer development study. [for space shuttles

    NASA Technical Reports Server (NTRS)

    Brudnicki, M. J.

    1974-01-01

    A development test program of transducers for aerospace projects is described. Stability and performance of existing transducers, and improvements compatible with shuttle ECS requirements are investigated. These requirements incorporate design and development features into the transducers, and include the following: (1) improvement of overall transducer ruggedness and reliability; (2) common transducers for all ECS fluids that will be unaffected by long quiescent periods in the space environment, that will require no maintenance or refurbishing for at least 100 launches; and (3) appropriate self-check features that simplify checkout and maintenance. Models of three different transducers, a three-way valve for pressure transducers from closed liquid loops, surface-type platinum-wire resistance temperature sensors, and a nuclenics gaging system are evaluated. Tests and development improvements are described.

  7. The research of knitting needle status monitoring setup

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  9. Torsional dynamics of steerable needles: modeling and fluoroscopic guidance.

    PubMed

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

    2014-11-01

    Needle insertions underlie a diversity of medical interventions. Steerable needles provide a means by which to enhance existing needle-based interventions and facilitate new ones. Tip-steerable needles follow a curved path and can be steered by twisting the needle base during insertion, but this twisting excites torsional dynamics that introduce a discrepancy between the base and tip twist angles. Here, we model the torsional dynamics of a flexible rod-such as a tip-steerable needle-during subsurface insertion and develop a new controller based on the model. The torsional model incorporates time-varying mode shapes to capture the changing boundary conditions inherent during insertion. Numerical simulations and physical experiments using two distinct setups-stereo camera feedback in semitransparent artificial tissue and feedback control with real-time X-ray imaging in optically opaque artificial tissue-demonstrate the need to account for torsional dynamics in control of the needle tip. PMID:24860026

  10. Needle phobia: etiology, adverse consequences, and patient management.

    PubMed

    Sokolowski, Chester J; Giovannitti, Joseph A; Boynes, Sean G

    2010-10-01

    Needle phobia has profound health, dental, societal, and legal implications, and severe psychological, social, and physiologic consequences. There is genetic evidence for the physiologic response to needle puncture, and a significant familial psychological component, showing evidence of inheritance. Needle phobia is also a learned behavior. The dental practitioner must recognize patients with needle phobia before the administration of local anesthetics to identify patients who are potentially reactive and to prevent untoward sequelae. Needle phobia is highly associated with avoidance behavior, and the dentist must exhibit compassion and respect. To avoid bradycardia, hypotension, unconsciousness, convulsions, and possibly asystole, oral premedication with benzodiazepines or other antianxiety agents must be considered for patients who are needle phobic. Management of needle phobiaeinduced syncope includes perioperative monitoring, oxygen administration, positioning, atropine, and vasopressors. PMID:20831935

  11. Mixed mode fuel injector with individually moveable needle valve members

    DOEpatents

    Stewart, Chris; Chockley, Scott A.; Ibrahim, Daniel R.; Lawrence, Keith; Tomaseki, Jay; Azam, Junru H.; Tian, Steven Ye; Shafer, Scott F.

    2004-08-03

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.

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

    PubMed Central

    Lin, Jaung-Geng; Chou, Pei-Chi; Chu, Heng-Yi

    2013-01-01

    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. PMID:23935678

  13. Optical micromachined ultrasound transducers (OMUT)--a new approach for high-frequency transducers.

    PubMed

    Tadayon, Mohammad Amin; Ashkenazi, Shai

    2013-09-01

    The sensitivity and reliability of piezoelectric ultrasound transducers severely degrade in applications requiring high frequency and small element size. Alternative technologies such as capacitive micromachined ultrasound transducers (CMUT) and optical sensing and generation of ultrasound have been proposed and studied for several decades. In this paper, we present a new type of device based on optical micromachined ultrasound transducer (OMUT) technology. OMUTs rely on microfabrication techniques to construct micrometerscale air cavities capped by an elastic membrane. A modified photoresist bonding process has been developed to facilitate the fabrication of these devices. We will describe the design, fabrication, and testing of prototype OMUT devices which implement a receive-only function. Future design modifications are proposed for incorporating complete transmit¿receive functionality in a single element. PMID:24658733

  14. [Needling technique of Professor Li Yan-Fang].

    PubMed

    Li, Li-Jun

    2014-01-01

    Experiences of needling techniques of Professor LI Ya- fang is introduced in this article. Gentle and superficial insertion is adopted by Professor LI in clinic. Emphases are put on the qi regulation function, needling sensation to the affected region and insertion with both hands, especially the function of the left hand as pressing hand. The gentle and superficial insertion should be done as the follows: hold the needle with the right hand, press gently along the running course of meridians with the left hand to promote qi circulation, hard pressing should be applied at acupoints to disperse the local qi and blood, insert the needle gently and quickly into the subcutaneous region with the right hand, and stop the insertion when patient has the needling sensation. While the fast needling is characterized with shallow insertion and swift manipulation: the left hand of the manipulator should press first along the running course of the meridian, and fix the local skin, hold the needle with the right hand and insert the needle quickly into the acupoint. Withdrawal of the needle should be done immediately after the reinforcing and reducing manipulations. Professor LI is accomplished in qi regulation. It is held by him that regulating qi circulation is essence of acupuncture, letting the patient get the needling sensation is the most important task of needling. Lifting, thrusting and rotation manipulations should be applied to do reinforcing or reducing. The tissue around the tip of the needle should not be too contracted or too relaxed, and the resistance should not be too strong or too weak. The feeling of the insertion hand of the practitioner should not be too smooth or too hesitant. Needle should be inserted into the skin quickly at the moment of hard pressing by the left hand. And then, slow rotation and gentle lifting and thrusting can be applied to promote the needling sensation like electric current pass through and to reach the affected region along the

  15. Maxillofacial Changes in Melnick-Needles Syndrome.

    PubMed

    Albuquerque do Nascimento, Leilane Larissa; Salgueiro, Monica da Consolação Canuto; Quintela, Mariana; Teixeira, Victor Perez; Mota, Ana Carolina Costa; de Godoy, Camila Haddad Leal; Bussadori, Sandra Kalil

    2016-01-01

    Background. Melnick-Needles Syndrome is rare congenital hereditary skeletal dysplasia caused by mutations in the FLNA gene, which codifies the protein filamin A. This condition leads to serious skeletal abnormalities, including the stomatognathic region. Case Presentation. This paper describes the case of a 13-year-old girl diagnosed with Melnick-Needles Syndrome presenting with different forms of skeletal dysplasia, such as cranial hyperostosis, short upper limbs, bowed long bones, metaphyseal thickening, genu valgum (knock-knee), shortened distal phalanges, narrow pelvis and shoulders, rib tapering and irregularities, elongation of the vertebrae, kyphoscoliosis, micrognathia, hypoplastic coronoid processes of the mandible, left stylohyoid ligament suggesting ossification, and dental development anomalies. Conclusion. Knowledge of this rare syndrome on the part of dentists is important due to the fact that this condition involves severe abnormalities of the stomatognathic system that cause an impact on the development of the entire face as well as functional and esthetic impairments. PMID:27478655

  16. FT Raman spectroscopy of Norway spruce needles

    NASA Astrophysics Data System (ADS)

    Matejka, P.; Pleserova, L.; Budinova, G.; Havirova, K.; Nahlik, J.; Skacel, F.; Volka, Karel

    2001-02-01

    12 Norway spruce [Picea abies (L.) Karst.] needles represent a very useful bioindicator of the air pollution. They serve not only as natural samplers of the pollutants but micromorphology of the epistomatal area can be directly correlated with an environmental stress. The needles of trees growing in polluted areas exhibit different types of injury to the epicuticular wax layer. It is evident that these changes of the morphology of the wax layers are connected also with the changes of their chemical composition and so a potential of the FT Raman spectroscopy was tested to serve as a screening method of these changes. In this work variability of the spectra with the age and with the position in the tree, in the locality, and also in the different localities of the Czech Republic was studied and evaluated in comparison with results of electron scanning microscopy.

  17. Monopolar needle electrode spatial recording characteristics.

    PubMed

    King, J C; Dumitru, D; Stegeman, D

    1996-10-01

    The recording characteristics of the monopolar needle in three dimensions have not been well established. A simple spherical recording territory is commonly assumed with the very tip proposed to have a greater spatial recording sensitivity by some authors. We demonstrate by enlarged physical modeling in a homogeneous volume conductor that the recorded amplitude diminishes more gradually radially away from the conical surface than distally past the tip or proximal to the insulation edge. The sensitivity over the exposed metallic surface is found to be uniformly proportional to the area, which results in relatively less sensitivity at the tip than the middle and proximal portions of the conical recording surface. The overall spatial amplitude recording characteristics can be better described by an apple shape than a sphere, centered at the midportion of the exposed conical surface. A better appreciation of the actual spatial recording characteristics of the monopolar needle electrode can result in more accurate physiologic interpretations of quantitative motor unit analysis. PMID:8808657

  18. Skinny needle pyelography. An advance in uroradiology.

    PubMed

    Hare, W S; McOmish, D

    1981-08-01

    Diagnostic puncture of the renal pelvis with a fine-gauge needle inserted under radiological and ultrasound control, has been performed in more than 100 cases. The method is safe, easy to perform for those trained in imaging modalities, and causes little discomfort. Pyelography and pressure flow studies can be made and urine specimens obtained from the upper urinary tract. Skinny needle pyelography is indicated in unilateral non-visualization of the ureter on intravenous pyelography, in acute oliguric renal failure when ultrasound reveals dilated ureters, and when retrograde pyelography is not feasible. The method is cost-effective, as it can be performed on outpatients as a follow-on procedure after intravenous pyelography or renal ultrasound scanning. PMID:7026995

  19. Maxillofacial Changes in Melnick-Needles Syndrome

    PubMed Central

    Albuquerque do Nascimento, Leilane Larissa; Salgueiro, Monica da Consolação Canuto; Quintela, Mariana; Mota, Ana Carolina Costa

    2016-01-01

    Background. Melnick-Needles Syndrome is rare congenital hereditary skeletal dysplasia caused by mutations in the FLNA gene, which codifies the protein filamin A. This condition leads to serious skeletal abnormalities, including the stomatognathic region. Case Presentation. This paper describes the case of a 13-year-old girl diagnosed with Melnick-Needles Syndrome presenting with different forms of skeletal dysplasia, such as cranial hyperostosis, short upper limbs, bowed long bones, metaphyseal thickening, genu valgum (knock-knee), shortened distal phalanges, narrow pelvis and shoulders, rib tapering and irregularities, elongation of the vertebrae, kyphoscoliosis, micrognathia, hypoplastic coronoid processes of the mandible, left stylohyoid ligament suggesting ossification, and dental development anomalies. Conclusion. Knowledge of this rare syndrome on the part of dentists is important due to the fact that this condition involves severe abnormalities of the stomatognathic system that cause an impact on the development of the entire face as well as functional and esthetic impairments. PMID:27478655

  20. Needle tip localization using stylet vibration.

    PubMed

    Harmat, Adam; Rohling, Robert N; Salcudean, Septimiu E

    2006-09-01

    Power Doppler ultrasound is used to localize the tip of a needle by detecting physical vibrations. Two types of vibrations are investigated, lateral and axial. The lateral vibrations are created by rotating a stylet, whose tip is slightly bent, inside a stationary cannula while the stylet is completely within the cannula. The minute deflection at the needle tip when rotated causes tissue motion. The axial vibration is induced by extending and retracting a straight stylet inside a stationary cannula. The stylet's tip makes contact with the tissue and causes it to move. The lateral vibration method was found to perform approximately the same under a variety of configurations (e.g., different insertion angles and depths) and better than the axial vibration method. Tissue stiffness affects the performance of the lateral vibration method, but good images can be obtained through proper tuning of the ultrasound machine. PMID:16965974

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

    PubMed

    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

  2. West Needle Wilderness study area, Colorado

    SciTech Connect

    Van Loenen, R.E.; Scott, D.C.

    1984-01-01

    The West Needle Wilderness study area, southwestern Colorado, was evaluated for mineral-resource potential in 1982. An area extending westward into the wilderness near the Elk Park mine, has a probable mineral-resource potential for uranium. Uranium resources, and associated silver, nickel, cobalt, and copper, are located at the Elk Park mine, directly adjacent to the eastern study area boundary. No potential for other mineral or energy resources was identified in this study.

  3. Fine needle aspiration cytology of gastric carcinoma.

    PubMed Central

    Allen, D. C.; Irwin, S. T.

    1997-01-01

    Four patients between 58 and 81 years of age undergoing investigation and endoscopic biopsy for gastric carcinoma also were subjected to direct-vision fine needle aspiration cytology of their mucosal lesions which yielded malignant cells. The relevance of this technique is discussed regarding both intrinsic and extrinsic lesions of the gastrointestinal tract. Images Fig 1. (a) Fig 1. (b) Fig 2. (a) Fig 2. (b) PMID:9414941

  4. Randomized Trial of Conventional Transseptal Needle Versus Radiofrequency Energy Needle Puncture for Left Atrial Access (the TRAVERSE‐LA Study)

    PubMed Central

    Hsu, Jonathan C.; Badhwar, Nitish; Gerstenfeld, Edward P.; Lee, Randall J.; Mandyam, Mala C.; Dewland, Thomas A.; Imburgia, Kourtney E.; Hoffmayer, Kurt S.; Vedantham, Vasanth; Lee, Byron K.; Tseng, Zian H.; Scheinman, Melvin M.; Olgin, Jeffrey E.; Marcus, Gregory M.

    2013-01-01

    Background Transseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access. Methods and Results In this prospective, single‐blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK‐1) transseptal needle. In an intention‐to‐treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P=0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P<0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P<0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]). Conclusions Use of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01209260. PMID:24045120

  5. Yield of new versus reused endobronchial ultrasound-guided transbronchial needle aspiration needles: A retrospective analysis of 500 patients

    PubMed Central

    Dhooria, Sahajal; Sehgal, Inderpaul Singh; Gupta, Nalini; Ram, Babu; Aggarwal, Ashutosh Nath; Behera, Digambar; Agarwal, Ritesh

    2016-01-01

    Background: Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) requires a dedicated needle for aspiration of mediastinal lesions. There is no data on reuse of these needles. Methods: This is a retrospective study of patients who underwent EBUS-TBNA with either new or reused EBUS-TBNA needles. The needles were reused after thorough cleaning with filtered water and organic cleaning solution, disinfection with 2.4% glutaraldehyde solution followed by ethylene oxide sterilization. The yield of EBUS-TBNA was compared between the two groups. Results: A total of 500 EBUS-TBNA procedures (351 new, 149 reused needles) were performed. The baseline characteristics were different in the two groups with suspected granulomatous disorders (sarcoidosis or tuberculosis) being significantly more common in the new compared to the reused needle group. Similarly, the median, interquartile range number of lymph node stations sampled, and the total number of passes were significantly higher in the new versus the reused needle group. The diagnostic yield was significantly higher with new needle as compared to reused needle (65.2% vs. 53.7%, P = 0.02). On multivariate logistic regression analysis, clinical suspicion of granulomatous disorders (odds ratio 1.86 [95% confidence interval, 1.20-2.87], P = 0.005) was the only predictor of diagnostic yield, after adjusting for the type of needle (new or reused), total number of passes and the number of lymph node stations sampled. No case of mediastinitis was encountered in either group. Conclusions: The yield of EBUS-TBNA might be similar with single reuse of needles as compared to new needles. However, reuse of needle should be performed only when absolutely necessary. PMID:27578927

  6. Exploration of new electroacupuncture needle material.

    PubMed

    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

  7. Exploration of New Electroacupuncture Needle Material

    PubMed Central

    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

  8. A high-temperature wideband pressure transducer

    NASA Technical Reports Server (NTRS)

    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. Liquid-immersible electrostatic ultrasonic transducer

    NASA Technical Reports Server (NTRS)

    Cantrell, J. H., Jr.; Heyman, J. S.; Yost, W. T.; Torbett, M. A.; Breazeale, M. A. (Inventor)

    1982-01-01

    A broadband megahertz range electrostatic acoustic transducer for use in a liquid environment is described. A liquid tight enclosure includes a metallic conducting membrane as part of its outside surface and has a means inside the liquid tight enclosure for applying a tension to the membrane and for mounting an electrode such that the flat end of the electrode is aproximately parallel to the membrane. The invention includes structure and a method for ensuring that the membrane and the flat end of the electrode are exactly parallel and a fixed predetermined distance from each other.

  10. Electrotactile display using microfabricated micro-needle array

    NASA Astrophysics Data System (ADS)

    Kitamura, N.; Chim, J.; Miki, N.

    2015-02-01

    This paper describes an electrotactile display with micro-needle electrodes. The electrotactile display can produce tactile sensations by stimulating tactile receptors using an electric current. Micro-needle electrodes can drastically decrease the threshold voltage required to stimulate tactile receptors by penetrating the stratum corneum, which has a higher impedance than the dermis. In addition, the optimized length of the needle allows us to stimulate tactile receptors painlessly. In the present study, we developed a process for fabricating a micro-needle array in which the length and tip radius can be controlled using electrochemical etching. A micro-needle array was successfully fabricated to form an electrotactile display. In addition, we experimentally determined the suitable shape of the micro-needle electrodes for electrotactile display applications. When the tip radius of the needle is too small, the impedance between the finger and micro-needles becomes large due to the small contact area. On the other hand, when the tip radius is too large, the needle cannot penetrate the skin surface and the impedance is not sufficiently small. The experiments verified the superiority of needle electrode devices to flat electrode devices with respect to the threshold voltage at each frequency.

  11. Ultrasound-guided robot for flexible needle steering.

    PubMed

    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

  12. The effects of needle deformation during lumbar puncture

    PubMed Central

    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

  13. Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules.

    PubMed

    Raikov, Nikolai; Nonchev, Boyan; Chaushev, Borislav; Vjagova, Diyana; Todorov, Svetoslav; Bocheva, Yana; Malceva, Daniela; Vicheva, Snejinka; Raikova, Asyia; Argatska, Antoaneta; Raikov, Miroslav

    2016-01-01

    The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy. PMID:26841375

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

    PubMed

    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

  15. Floating Ultrasonic Transducer Inspection System and Method for Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N. (Inventor); Johnston, Patrick H. (Inventor)

    2016-01-01

    A method for inspecting a structural sample using ultrasonic energy includes positioning an ultrasonic transducer adjacent to a surface of the sample, and then transmitting ultrasonic energy into the sample. Force pulses are applied to the transducer concurrently with transmission of the ultrasonic energy. A host machine processes ultrasonic return pulses from an ultrasonic pulser/receiver to quantify attenuation of the ultrasonic energy within the sample. The host machine detects a defect in the sample using the quantified level of attenuation. The method may include positioning a dry couplant between an ultrasonic transducer and the surface. A system includes an actuator, an ultrasonic transducer, a dry couplant between the transducer the sample, a scanning device that moves the actuator and transducer, and a measurement system having a pulsed actuator power supply, an ultrasonic pulser/receiver, and a host machine that executes the above method.

  16. Electronic scanning pressure measuring system and transducer package

    NASA Technical Reports Server (NTRS)

    Coe, C. F. (Inventor); Parra, G. T.

    1984-01-01

    An electronic scanning pressure system that includes a plurality of pressure transducers is examined. A means obtains an electrical signal indicative of a pressure measurement from each of the plurality of pressure transducers. A multiplexing means is connected for selectivity supplying inputs from the plurality of pressure transducers to the signal obtaining means. A data bus connects the plurality of pressure transducers to the multiplexing means. A latch circuit is connected to supply control inputs to the multiplexing means. An address bus is connected to supply an address signal of a selected one of the plurality of pressure transducers to the latch circuit. In operation, each of the pressure transducers is successively scanned by the multiplexing means in response to address signals supplied on the address bus to the latch circuit.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Current transducers used in power line measurements

    NASA Astrophysics Data System (ADS)

    Milcarz, Sz.; Gołebiowski, J.

    2014-08-01

    There are many solutions used for current measurements in power lines. The study shows a transducer consisting of a ferromagnetic core, a beam placed in an air-gap and a sensor for optical readout. The beam is made of silicon with a thin 50%Ni50%Fe film. The material of the core is permalloy. A distribution of magnetic field depends on current supplying the power line. The beam is deflected due to magnetic field in the air-gap. A deflection of the beam is measured by the optical fibre sensor. Its advantage is simple design, high precision of processing, non-electric transmission, low costs and ability of a non-contact measurement. Comsol Multiphysics 4.4 and Magnetic Fields Module (mef) were used for modeling. An influence of magnetic circuit's materials and dimensions of the ferromagnetic core and the air-gap were tested in order to determine the most sufficient distribution of magnetic field in the air-gap. The study shows results of the modeling of the transducer compared to practical results for a similar construction scaled down to lower current values.

  19. Development of Terfenol-D transducer material

    NASA Astrophysics Data System (ADS)

    Lindgren, E. A.; Haroush, S.; Poret, J. C.; Mazzatesta, A. D.; Rosen, M.; Wun-Fogle, M.; Restorff, J. B.; Clark, A. E.; Lindberg, J. F.

    1998-06-01

    Terfenol-D, Tb1-xDyxFe2 (x≅0.7), is successfully used as a magnetostrictive transducer material for low-frequency applications. To extend the frequency range of magnetostrictive transducers into the high kHz and MHz range, new materials processing techniques must be developed to minimize eddy current losses. The method that has demonstrated the greatest potential to date is based on rapid solidification by melt spinning to obtain thin strips of material. The objective of this program includes refining the casting procedure to yield ribbons with the [111] direction oriented along the length of the ribbon, with the (110) plane in the plane of the ribbon. The crystallographic orientation of the Terfenol-D ribbons have been controlled by varying the cooling rate of the melt-spinning process. The cooling rates were controlled by a number of parameters in the melt-spinning process and ribbons have been obtained with an enhancement of the (110) plane parallel to the surface of the ribbon. Magnetostrictive measurements under tensile stresses up to 3 MPa and magnetic fields up to 4 kOe yielded magnetostrictive displacements of 850×10-6.

  20. Flexible ultrasonic transducers incorporating piezoelectric fibres.

    PubMed

    Harvey, Gerald; Gachagan, Anthony; Mackersie, John W; McCunnie, Thomas; Banks, Robert

    2009-09-01

    It is possible to produce a high-performance, flexible 1-3 connectivity piezoelectric ceramic composite with conventional methods but the process is difficult and time-consuming. Extensive finite element modeling was used to design a piezocomposite structure which incorporated randomly positioned piezoceramic fibers in a polymer matrix. Simple manufacturing techniques were developed which resulted in the production of large numbers of fully populated fiber composites that offered performance comparable with a conventional 1-3 piezocomposite. A modified process facilitated the production of efficient fiber piezocomposite elements separated by polymer channels which conformed to a highly flexible (13 mm radius of curvature), 2-D matrix array configuration. This arrangement has been termed a Composite Element Composite Array Transducer, or CECAT. These devices were evaluated in terms of their impedance spectra, pulse-echo response, and surface displacement characteristics. The random piezoceramic fiber arrangements showed comparable sensitivity and bandwidth to periodic devices while minimizing the parasitic interpillar modes associated with periodic structures. Investigations have indicated that CECAT arrays constructed with 250 microm diameter fibers can be operated at frequencies of up to 3 MHz and transducers incorporating 10 microm diameter fibers can extend the frequency range above 6 MHz. Conversely, improved low-frequency devices can be produced with taller pillars than possible with conventional manufacturing techniques. PMID:19812003

  1. Capacitive micromachined ultrasonic transducers: fabrication technology.

    PubMed

    Ergun, Arif Sanli; Huang, Yongli; Zhuang, Xuefeng; Oralkan, Omer; Yaralioglu, Goksen G; Khuri-Yakub, Butrus T

    2005-12-01

    Capacitive micromachined ultrasonic transducer (cMUT) technology is a prime candidate for next generation imaging systems. Medical and underwater imaging and the nondestructive evaluation (NDE) societies have expressed growing interest in cMUTs over the years. Capacitive micromachined ultrasonic transducer technology is expected to make a strong impact on imaging technologies, especially volumetric imaging, and to appear in commercial products in the near future. This paper focuses on fabrication technologies for cMUTs and reviews and compares variations in the production processes. We have developed two main approaches to the fabrication of cMUTs: the sacrificial release process and the recently introduced wafer-bonding method. This paper gives a thorough review of the sacrificial release processes, and it describes the new wafer-bonding method in detail. Process variations are compared qualitatively and quantitatively whenever possible. Through these comparisons, it was concluded that wafer-bonded cMUT technology was superior in terms of process control, yield, and uniformity. Because the number of steps and consequent process time were reduced (from six-mask process to four-mask process), turn-around time was improved significantly. PMID:16463490

  2. Acoustic lens for capacitive micromachined ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Chang, Chienliu; Firouzi, Kamyar; Park, Kwan Kyu; Sarioglu, Ali Fatih; Nikoozadeh, Amin; Yoon, Hyo-Seon; Vaithilingam, Srikant; Carver, Thomas; Khuri-Yakub, Butrus T.

    2014-08-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing.

  3. Electret Acoustic Transducer Array For Computerized Ultrasound Risk Evaluation System

    DOEpatents

    Moore, Thomas L.; Fisher, Karl A.

    2005-08-09

    An electret-based acoustic transducer array is provided and may be used in a system for examining tissue. The acoustic transducer array is formed with a substrate that has a multiple distinct cells formed therein. Within each of the distinct cells is positioned an acoustic transducing element formed of an electret material. A conductive membrane is formed over the distinct cells and may be flexible.

  4. Low-cost ultrasonic lamb-wave transducer

    NASA Technical Reports Server (NTRS)

    Kammerer, C. C.

    1978-01-01

    Transducer propagates Lamb wave through thin aluminum sheet material. Model includes two elements that measure effects of damping and loading which, in turn, are indirectly equated to bond integrity. Transducer has been used to evaluate bond integrity of aluminum facing adhesively bonded to aluminum facing. Because of versatility, it is now possible to inspect many objects of different configurations that could not be reached with earlier transducers.

  5. An ultrasonic transducer with Gaussian radial velocity distribution

    NASA Technical Reports Server (NTRS)

    Zerwekh, P. S.; Claus, R. O.

    1981-01-01

    A transducer with a velocity profile which is Gaussian as a function of radius and independent of angle is described. In materials evaluation applications requiring the interrogation of modified far field patterns of an ultrasonic transducer, it is desirable to use a transducer which produces a beam with a Gaussian profile. A computer aided electrode design and calibrated three dimensional interferometric optical and ultrasonic measurements of the far field distribution are presented.

  6. Comparative study of acceleration transducers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Buchczik, Dariusz; Wyżgolik, Roman; Pietraszek, Stanisław

    2006-10-01

    The results of comparative studies of the metrological parameters of acceleration transducers constructed in Institute of Electronics, Silesian University of Technology is presented in this article. The construction of the transducers is based on commercially available monolithic accelerometers and optimized for biomedical applications. The parameters determined during the tests are similar to the parameters of the monolithic accelerometers declared by their manufacturers. It proofs that both the mechanical and the electronic construction of the transducers are correct.

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

    PubMed Central

    Manière, Thibaut; Déry, Vincent

    2016-01-01

    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. PMID:27555874

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

    PubMed

    Adamowicz, Bartosz; Manière, Thibaut; Déry, Vincent; Désilets, Étienne

    2016-01-01

    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. PMID:27555874

  9. MR-guided aspiration biopsy: needle design and clinical trials.

    PubMed

    Mueller, P R; Stark, D D; Simeone, J F; Saini, S; Butch, R J; Edelman, R R; Wittenberg, J; Ferrucci, J T

    1986-12-01

    Nonferrous needles of pure brass, titanium, or copper, and ferrous needles of different alloys of stainless steel were analyzed for the size, area, and distribution of the image artifact created when the needles were placed in a 0.6-T magnet. Results demonstrated that a stainless steel prototype needle (type 316) would be visible on magnetic resonance images and would provide an artifact similar to that seen in computed tomographic-guided biopsies. Further testing of this prototype included assessment of the effect on the artifact when changes were made in annealing properties, gauge, length, needle-tip geometry, pulse sequence, and orientation relative to the magnetic field. To date, three human liver biopsies have been successfully and safely performed using a stainless steel type 316 needle. PMID:3786706

  10. HIV seropositivity of needles from shooting galleries in south Florida.

    PubMed

    Chitwood, D D; McCoy, C B; Inciardi, J A; McBride, D C; Comerford, M; Trapido, E; McCoy, H V; Page, J B; Griffin, J; Fletcher, M A

    1990-02-01

    Needle/syringe combinations were collected from three shooting galleries in South Florida and tested for the presence of antibodies to HIV-1. Fifteen of 148 needles (10.1 percent) tested positive for HIV-1 antibody. Seropositivity rates did not vary by the day of the week of collection, nor by shooting gallery from which they were collected. When the needle appeared to contain blood residue, 20.0 percent were positive versus 5.1 percent with no blood residue. These findings suggest that needles/syringes used in shooting galleries are likely to serve as reservoirs and/or vectors of transmission of the HIV-1 virus, and that although visual inspection of the needle/syringe may be useful in lessening the chance for transmission, even the visually "clean" needles may result in transmission of infection. PMID:2297056

  11. MR-compatible biopsy needle with enhanced tip force sensing

    PubMed Central

    Elayaperumal, Santhi; Bae, Jung Hwa; Christensen, David; Cutkosky, Mark R.; Daniel, Bruce L.; Costa, Joannes M.; Black, Richard J.; Faridian, Fereydoun; Moslehi, Behzad

    2015-01-01

    We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle’s inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip. The holes increase strain sensitivity, especially to axial forces, without significantly reducing the stiffness or strength. A comparison of the dynamic forces measured with the new needle and those obtained using a force/torque sensor at the needle base shows that the enhanced tip sensitivity is particularly noticeable when there is significant friction along the needle sleeve. PMID:26509189

  12. Picosecond optical vortex pulse illumination forms a monocrystalline silicon needle

    NASA Astrophysics Data System (ADS)

    Takahashi, Fuyuto; Miyamoto, Katsuhiko; Hidai, Hirofumi; Yamane, Keisaku; Morita, Ryuji; Omatsu, Takashige

    2016-02-01

    The formation of a monocrystalline silicon needle by picosecond optical vortex pulse illumination was demonstrated for the first time in this study. The dynamics of this silicon needle formation was further revealed by employing an ultrahigh-speed camera. The melted silicon was collected through picosecond pulse deposition to the dark core of the optical vortex, forming the silicon needle on a submicrosecond time scale. The needle was composed of monocrystalline silicon with the same lattice index (100) as that of the silicon substrate, and had a height of approximately 14 μm and a thickness of approximately 3 μm. Overlaid vortex pulses allowed the needle to be shaped with a height of approximately 40 μm without any changes to the crystalline properties. Such a monocrystalline silicon needle can be applied to devices in many fields, such as core-shell structures for silicon photonics and photovoltaic devices as well as nano- or microelectromechanical systems.

  13. Modeling of multilayered piezoelectric transducers with ultrasonic welding application

    NASA Astrophysics Data System (ADS)

    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.

  14. High Temperature Ultrasonic Transducer for Real-time Inspection

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:25482533

  16. Electrical characterization of coupled and uncoupled MEMS ultrasonic transducers.

    PubMed

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

    2003-03-01

    We report electrical characterization of micromachined polysilicon capacitive diaphragms for use as ultrasonic transducers. Admittance measurements yield insight into the resonant behavior and also the damping resulting from ultrasonic radiation and frictional forces caused by the etch release holes. Unbonded transducers exhibit sharp resonances with Q values that increase with decreasing air pressure. We also report for the first time direct bonding of these transducers to solid surfaces. Transducers survive the bonding process and show distinctly different displacement in response to applied dc bias. Finally, a single-degree-of-freedom model is used to obtain insight into the various contributions to damping. PMID:12699163

  17. Evaluation of several ultrasonic flowmeter transducers in cryogenic environment

    NASA Technical Reports Server (NTRS)

    Moughon, W. C.

    1981-01-01

    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.

  18. Evaluation of several ultrasonic flowmeter transducers in cryogenic environment

    NASA Astrophysics Data System (ADS)

    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.

  19. A new transducer system for direct motor unit force measurement.

    PubMed

    Turkawski, S J; van Ruijven, L J; van Kuyen, M; Schreurs, A W; Weijs, W A

    1996-11-01

    A new transducer was developed for in situ measurement of the force vector in a complex muscle. The transducer measures the magnitude, and the line of action of a force in a single plane. The dynamic range of the transducer is 0-5 N. This range includes the small forces developed by an active motor unit and the relatively large passive force of a whole muscle. In this study we present the details of the transducer design and specifications, and describe its application in the measurement of motor unit forces of the rabbit masseter muscle. PMID:8894930

  20. Chest Wall Dissemination of Nocardiosis after Percutaneous Transthoracic Needle Biopsy

    SciTech Connect

    Shimamoto, Hiroshi Inaba, Yoshitaka; Yamaura, Hidekazu; Sato, Yozo; Kamiya, Mika; Miyazaki, Masaya; Arai, Yasuaki; Horio, Yoshitsugu

    2007-07-15

    We described a case of chest wall dissemination after percutaneous transthoracic needle biopsy. A 65-year-old man had a lung nodule which was suspected to be lung carcinoma. He underwent percutaneous transthoracic needle biopsy using an 18G semiautomated biopsy needle and pathologic diagnosis showed organizing pneumonia. Two months after the biopsy, chest wall dissemination occurred. Implantation of carcinoma along the biopsy route was suspected, but the mass was actually due to pulmonary nocardiosis.

  1. Highly reliable multisensor array (MSA) smart transducers

    NASA Astrophysics Data System (ADS)

    Perotti, José; Lucena, Angel; Mackey, Paul; Mata, Carlos; Immer, Christopher

    2006-05-01

    Many developments in the field of multisensor array (MSA) transducers have taken place in the last few years. Advancements in fabrication technology, such as Micro-Electro-Mechanical Systems (MEMS) and nanotechnology, have made implementation of MSA devices a reality. NASA Kennedy Space Center (KSC) has been developing this type of technology because of the increases in safety, reliability, and performance and the reduction in operational and maintenance costs that can be achieved with these devices. To demonstrate the MSA technology benefits, KSC quantified the relationship between the number of sensors (N) and the associated improvement in sensor life and reliability. A software algorithm was developed to monitor and assess the health of each element and the overall MSA. Furthermore, the software algorithm implemented criteria on how these elements would contribute to the MSA-calculated output to ensure required performance. The hypothesis was that a greater number of statistically independent sensor elements would provide a measurable increase in measurement reliability. A computer simulation was created to answer this question. An array of N sensors underwent random failures in the simulation and a life extension factor (LEF equals the percentage of the life of a single sensor) was calculated by the program. When LEF was plotted as a function of N, a quasiexponential behavior was detected with marginal improvement above N = 30. The hypothesis and follow-on simulation results were then corroborated experimentally. An array composed of eight independent pressure sensors was fabricated. To accelerate sensor life cycle and failure and to simulate degradation over time, the MSA was exposed to an environmental tem-perature of 125°C. Every 24 hours, the experiment's environmental temperature was returned to ambient temperature (27°C), and the outputs of all the MSA sensor elements were measured. Once per week, the MSA calibration was verified at five different

  2. Lab in a needle for epidural space identification

    NASA Astrophysics Data System (ADS)

    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.

  3. The biopolitics of needle exchange in the United States

    PubMed Central

    McLean, Katherine

    2012-01-01

    Needle exchange began in the United States as a fragmented and illegal practice initiated by actors at the grassroots level; since the late 1980s, needle exchange has achieved increasing yet variable levels of institutional support across the country, receiving official sanction and funding from state and municipal governments. In turn, the practice(s) and discourse(s) of needle exchange have shifted significantly in many locales, becoming the purview of professional administration that advocates needle exchange as a necessary public health measure. This article is interested in the ways in which needle exchange has become implicated in and appropriated by networks of power seeking to discipline and regulate injection drug use. Drawing theoretically on Michel Foucault’s writings concerning biopower and governmentality, it will examine the proliferation of discourses, knowledges, and rules surrounding needle exchange in the United States. At the same time, this article will avoid a characterization of needle exchange that envisions the unilateral control of drug users by governmental power, illuminating instead both its negative and productive effects for drug users. Namely, it will explore how needle exchange creates both subjects of interest and subjects of resistance among drug users – that is to say, the governmentalization of needle exchange and its ‘clients’. PMID:22389572

  4. Serrated needle design facilitates precise round window membrane perforation.

    PubMed

    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

  5. Automatic needle segmentation in 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Ding, Mingyue; Cardinal, H. Neale; Guan, Weiguang; Fenster, Aaron

    2002-05-01

    In this paper, we propose to use 2D image projections to automatically segment a needle in a 3D ultrasound image. This approach is motivated by the twin observations that the needle is more conspicuous in a projected image, and its projected area is a minimum when the rays are cast parallel to the needle direction. To avoid the computational burden of an exhaustive 2D search for the needle direction, a faster 1D search procedure is proposed. First, a plane which contains the needle direction is determined by the initial projection direction and the (estimated) direction of the needle in the corresponding projection image. Subsequently, an adaptive 1D search technique is used to adjust the projection direction iteratively until the projected needle area is minimized. In order to remove noise and complex background structure from the projection images, a priori information about the needle position and orientation is used to crop the 3D volume, and the cropped volume is rendered with Gaussian transfer functions. We have evaluated this approach experimentally using agar and turkey breast phantoms. The results show that it can find the 3D needle orientation within 1 degree, in about 1 to 3 seconds on a 500 MHz computer.

  6. Evolution of transbronchial needle aspiration technique

    PubMed Central

    Liu, Qing-Hua; Ben, Su-Qin; Xia, Yang

    2015-01-01

    Transbronchial needle aspiration (TBNA) is an established technique to collect cell and tissue specimens from lesions outside the airway wall, generally guided by flexible bronchoscope under the direct visualization of the puncture site. TBNA has been utilized for 30 years, and now there is renewed interest in utilizing it in conjunction with endobronchial ultrasound. Although the basic operational principles have remained the same, conventional TBNA (cTBNA) and endobronchial ultrasound-guided TBNA (EBUS-TBNA) have been greatly improved over the years with the increased application in clinic and the advance of new technology. In this article we briefly discussed the evolution of TBNA technique and its future. PMID:26807269

  7. Catheter tip force transducer for cardiovascular research

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    A force transducer for measuring dynamic force activity within the heart of a subject essentially consists of a U-shaped beam of low elastic compliance material. Two lines extend from the beams's legs and a long coil spring is attached to the beam. A strain gauge is coupled to one of the beam's legs to sense deflections thereof. The beam with the tines and most of the spring are surrounded by a flexible tube, defining a catheter, which is insertable into a subject's heart through an appropriate artery. The tines are extractable from the catheter for implantation into the myocardium by pushing on the end of the spring which extends beyond the external end of the catheter.

  8. Development of piezoelectric composites for transducers

    NASA Astrophysics Data System (ADS)

    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

  9. Vertical positioning surveillance by magnetostrictive transducer

    NASA Astrophysics Data System (ADS)

    Carvalho, A. S.; Lopes, C.; Pinto, O. O.; Nunes, C. D.; Borges, M. F.; Strohaecker, T. R.

    2015-10-01

    This work purpose is to create a positioning automated system of a tailstock to perform impact resistance tests on silicone mammary implants. This system is capable to measure and oversight the positioning through interrelation between three main components: programmable logic controller, human-machine interface and magnetostrictive transducer. Together, these components form an operational closed loop that ensures an appropriate positioning for the impact device. The paper describes how the closed loop works and also the algorithm implemented in the programmable logic controller which surveys the positioning. As a last topic, the paper presents the operator work on the machine's operation in conjunction with human-machine interface. The results were satisfactory and in accordance with the limits determined on ABNT NBR ISO 14607 for this method of tests.

  10. Optically selective, acoustically resonant gas detecting transducer

    NASA Technical Reports Server (NTRS)

    Dimeff, J. (Inventor)

    1977-01-01

    A gas analyzer is disclosed which responds to the resonant absorption or emission spectrum of a specific gas by producing an acoustic resonance in a chamber containing a sample of that gas, and which measures the amount of that emission or absorption by measuring the strength of that acoustic resonance, e.g., the maximum periodic pressure, velocity or density achieved. In the preferred embodiment, a light beam is modulated periodically at the acoustical resonance frequency of a closed chamber which contains an optically dense sample of the gas of interest. Periodic heating of the absorbing gas by the light beam causes a cyclic expansion, movement, and pressure within the gas. An amplitude is reached where the increased losses were the cyclic radiation energy received. A transducing system is inclined for converting the pressure variations of the resonant gas into electronic readout signals.

  11. A symmetrical low temperature pressure transducer

    NASA Astrophysics Data System (ADS)

    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 (T<4.2 K). A movable electrode is attached to two sets of miniature bellows such that the electrode position is determined by the differential pressure across the device. The movable electrode is located between two fixed electrodes, thus forming a pair of variable capacitors. A dedicated charge amplifier is used to convert the pressure induced capacitance 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.

  12. Torsional ultrasonic transducer computational design optimization.

    PubMed

    Melchor, J; Rus, G

    2014-09-01

    A torsional piezoelectric ultrasonic sensor design is proposed in this paper and computationally tested and optimized to measure shear stiffness properties of soft tissue. These are correlated with a number of pathologies like tumors, hepatic lesions and others. The reason is that, whereas compressibility is predominantly governed by the fluid phase of the tissue, the shear stiffness is dependent on the stroma micro-architecture, which is directly affected by those pathologies. However, diagnostic tools to quantify them are currently not well developed. The first contribution is a new typology of design adapted to quasifluids. A second contribution is the procedure for design optimization, for which an analytical estimate of the Robust Probability Of Detection, called RPOD, is presented for use as optimality criteria. The RPOD is formulated probabilistically to maximize the probability of detecting the least possible pathology while minimizing the effect of noise. The resulting optimal transducer has a resonance frequency of 28 kHz. PMID:24882020

  13. Active acoustical impedance using distributed electrodynamic transducers

    NASA Astrophysics Data System (ADS)

    Collet, M.; Berthillier, M.; David, P.

    2006-03-01

    New miniaturization and integration capabilities available from the emerging MEMS technology will allow silicon-based artificial skins involving thousands of elementary actuators to be developed in the near future. SMART structures combining large arrays of elementary motion pixels coated with macroscopic components are thus being studied so that fundamental properties such as shape, stiffness, color, and even reflectivity of light and sound could be dynamically adjusted. This paper investigates acoustic impedance capabilities of a set of distributed transducers connected with suitable controlling laws. Basically, we search to design an integrated electro-mechanical system which presents a global behavior with appropriate acoustical characteristics. This problem is intrinsically connected with the control of multi physical system based on PDE and with the notion of multi-scaled physics when we dispose MEMS devices. By using specific techniques based on partial differential equation control theory, we have first build a simple boundary control equation able to annihilate wave reflection. The obtained control strategies can also be discretized to be implemented like a zero or first order spatial operator. Thus, we can use quasi-collocated transducers and their well-known poles-zeros interlacing property to guarantee robust stability. This paper aims at showing in a first part how a well controlled semi-distributed active skin can substantially modify transmissibility or reflectivity of the corresponding homogeneous wall. In a second part numerical and experimental results underline the capabilities of the method. Finally efficiency of such a device is compared theoretically with those obtained by classical x-filtered LMS strategy.

  14. Ultrasonic 2D matrix PVDF transducer

    NASA Astrophysics Data System (ADS)

    Ptchelintsev, A.; Maev, R. Gr.

    2000-05-01

    During the past decade a substantial amount of work has been done in the area of ultrasonic imaging technology using 2D arrays. The main problems arising for the two-dimensional matrix transducers at megahertz frequencies are small size and huge count of the elements, high electrical impedance, low sensitivity, bad SNR and slower data acquisition rate. The major technological difficulty remains the high density of the interconnect. To solve these problems numerous approaches have been suggested. In the present work, a 24×24 elements (24 transmit+24 receive) matrix and a switching board were developed. The transducer consists of two 52 μm PVDF layers each representing a linear array of 24 elements placed one on the top of the other. Electrodes in these two layers are perpendicular and form the grid of 0.5×0.5 mm pitch. The layers are bonded together with the ground electrode being monolithic and located between the layers. The matrix is backed from the rear surface with an epoxy composition. During the emission, a linear element from the emitting layer generates a longitudinal wave pulse propagating inside the test object. Reflected pulses are picked-up by the receiving layer. During one transmit-receive cycle one transmit element and one receive element are selected by corresponding multiplexers. These crossed elements emulate a small element formed by their intersection. The present design presents the following advantages: minimizes number of active channels and density of the interconnect; reduces the electrical impedance of the element improving electrical matching; enables the transmit-receive mode; due to the efficient backing provides bandwidth and good time resolution; and, significantly reduces the electronics complexity. The matrix can not be used for the beam steering and focusing. Owing to this impossibility of focusing, the penetration depth is limited as well by the diffraction phenomena.

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

    PubMed

    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

  16. Particle formation and risk of embolization during transseptal catheterization: comparison of standard transseptal needles and a new radiofrequency transseptal needle

    PubMed Central

    Tiongson, Jay; Oshodi, Ganiyu

    2011-01-01

    Objective Anecdotally, the Brockenbrough transseptal needle generates plastic particles through a process of skiving (shaving off particles), when advanced through the dilator and sheath. This study was performed to assess particle creation by the Brockenbrough needle during transseptal catheterization. We explore strategies that may reduce this phenomenon, including use of the Brockenbrough stylet and a radiofrequency transseptal needle. Method In vitro simulations of transseptal catheterization were performed using Brockenbrough transseptal needles and a new radiofrequency transseptal needle. Particles that were created during advancement of transseptal needles through the sheath and dilator were collected and analyzed. Particles in the visible range of 50 μm to 4 mm were identified using a light microscope, whereas particles in the sub-visible, yet clinically relevant range of 10 to 50 μm, were counted using a light obscuration method. Results All simulated procedures using the Brockenbrough transseptal needles, with or without a stylet, generated visible particles. Simulated procedures with the radiofrequency transseptal needle generated no visible particles. A greater number of sub-visible particles were generated with the standard Brockenbrough transseptal needle (BKR-1) without stylet compared with the standard Brockenbrough needle (BRK-1) with stylet, the Brockenbrough extra sharp (BRK-1XS) needle with or without stylet, and the radiofrequency needle (NRG C1). Conclusion Clinically relevant particles, both visible and sub-visible, with the potential for causing embolic complications, are generated by the BRK-1 needle without stylet. Use of a stylet in the BRK-1 needle, or the BRK-1XS needle with or without stylet, appears to reduce the size and amount of particles created. The NRG C1 needle appears to eliminate visible particles and is comparable to the BRK-1 with stylet and the BRK-1XS with or without stylet in generation of sub-visible particles

  17. Modeling of friction force based on relative velocity between liver tissue and needle for needle insertion simulation.

    PubMed

    Kobayashi, Yo; Sato, Takahiro; Fujie, Masakatsu G

    2009-01-01

    Needle insertion treatments require accurate placement of the needle tip into the target cancer. However, it is difficult to insert the needle into the cancer because of cancer displacement due to the organ deformation. Then, a path planning using needle insertion simulation to analyze the deformation of the organ is important for the accurate needle insertion. A frictional model for needle insertion simulation is presented in this report. In particular, we focus on a model of frictional force based on the relative velocity between the needle and liver tissue ranging from hyper slow velocity. First, in vitro experiments using hog liver were performed at several relative velocities in order to measure the velocity dependence of the frictional force. Several needle insertion experiments were performed under identical conditions in order to deal with the variance of experimental data. The 60 frictional force data were used to obtain average data at each relative velocity. Second, the model of frictional force was developed using the averages of the experimental results. This model is defined according to the relative velocity ranging from hyper slow velocity. Finally, an evaluation experiment was carried out. The data obtained by the evaluation experiment reveals that the frictional force changes according to the relative velocity between the needle and liver tissue. The experimental results support the validity of proposed model of frictional force. PMID:19964671

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

    PubMed Central

    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

  19. A Needle-Free Injection System (INJEX™) with lidocaine for epidural needle insertion: A randomized controlled trial

    PubMed Central

    Gozdemir, Muhammet; Demircioglu, Ruveyda Irem; Karabayirli, Safinaz; Sert, Huseyin; Muslu, Bunyamin; Usta, Burhanettin; Yazici, Ummugulsum

    2016-01-01

    Objectives: Local anesthetic infiltration is also a process of a painful process itself. INJEX™ technology, known as “Needle-free” drug delivery system, was designed for reducing the pain associated with cutaneous procedures. We conducted a prospective, randomized trial to evaluate the application of lidocaine with INJEX™ system and 27-gauge needle. Methods: A total of 60 consecutive patients were allocated to receive either INJEX group or 27-gauge needle group. Local anesthetic infiltration was applied two minutes before epidural needle insertion. Results: Mean VAS, at the time of local anesthetic injection was 0 for group I and 2 for group II. When the effect of epidural needle insertion was compared, the mean VAS score was one versus two for Group-I versus Group-II, respectively. Lidocaine applied with the INJEX™ system before epidural needle insertion significantly reduced the intensity of pain during that procedure and was least effective the lidocaine applied with the 27-gauge needle and patients felt less pain during at the time of local anesthetic injection in Group-I. Conclusion: Needle-free delivery of lidocaine is an effective, easy to-use and noninvasive method of providing local anesthesia for the epidural needle insertion. PMID:27375728

  20. A new needle on the block: EchoTip ProCore endobronchial ultrasound needle

    PubMed Central

    Dincer, H Erhan; Andrade, Rafael; Zamora, Felix; Podgaetz, Eitan

    2016-01-01

    Endobronchial ultrasound has become the first choice standard of care procedure to diagnose benign or malignant lesions involving mediastinum and lung parenchyma adjacent to the airways owing to its characteristics of being real-time and minimally invasive. Although the incidence of lung cancer has been decreasing, it is and will be the leading cause of cancer-related mortality in the next few decades. When compared to other cancers, lung cancer kills more females than breast and colon cancers combined and more males than colon and prostate cancers combined. The type of lung cancer has changed in recent decades and adenocarcinoma has become the most frequent cell type. Prognosis of lung cancer depends upon the cell type and the staging at the time of diagnosis. The cell type and molecular characteristics of adenocarcinoma may allow individualized targeted treatment. Other malignant conditions in the mediastinum and lung (eg, metastatic lung cancers and lymphoma) can be biopsied using endobronchial ultrasound needles. Endobronchial ultrasound needle biopsies provides mostly cytology specimens due to its small sizes of needles (22 gauge or larger) which may not give enough tissue to make a definitive diagnosis in malignant (eg, lymphoma) or benign conditions (eg, sarcoidosis). EchoTip ProCore endobronchial needle released in early 2014 provides histologic biopsy material. Larger tissue biopsies may potentially provide a higher diagnostic yield and it eliminates mediastinoscopy or other surgical interventions. Here we aim to review bronchoscopic approach in the diagnosis of mediastinal lesions with emphasis of EchoTip ProCore needles. PMID:27099535

  1. Respiratory Belt Transducer Constructed Using a Singing Greeting Card Beeper

    ERIC Educational Resources Information Center

    Bhaskar, Anand; Subramani, Selvam; Ojha, Rajdeep

    2013-01-01

    An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers,…

  2. Resonant acoustic transducer system for a well drilling string

    DOEpatents

    Kent, William H.; Mitchell, Peter G.

    1981-01-01

    For use in transmitting acoustic waves propagated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting resonant operation in the desired low frequency range.

  3. Resonant acoustic transducer system for a well drilling string

    DOEpatents

    Nardi, Anthony P.

    1981-01-01

    For use in transmitting acoustic waves propated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting a resonant operation in the desired low frequency range.

  4. A Force Transducer from a Junk Electronic Balance

    ERIC Educational Resources Information Center

    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…

  5. A force transducer from a junk electronic balance

    NASA Astrophysics Data System (ADS)

    Munguía Aguilar, Horacio; Armenta Aguilar, Francisco

    2009-11-01

    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 careful calibration and proper conditioning.

  6. 21 CFR 868.2900 - Gas pressure transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Gas pressure transducer. 868.2900 Section 868.2900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2900 Gas pressure transducer....

  7. How to design and construct multielement ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Burrier, R. A.; Claus, R. O.

    1984-01-01

    The practical 'how to' design and construction of multielement ultrasonic transducers are described. First, design procedures based on direct calculations of the desired acoustic field are reviewed. Second, techniques for implementing these designs using piezoelectric active elements are discussed. Finally, optical and acoustic test methods for transducer calibration are indicated.

  8. Influence of backing and matching layers in ultrasound transducer performance

    NASA Astrophysics Data System (ADS)

    do Nascimento, Valeria M.; Nantes Button, Vera L. d. S.; Maia, Joaquim M.; Costa, Eduardo T.; Oliveira, Eduardo J. V.

    2003-05-01

    In this work we have investigated the influence of the backing layer composition and the matching layer thickness in the performance of ultrasound transducers constructed with piezoelectric ceramic disks. We have constructed transducers with backing layers of different compositions, using mixtures of epoxy with alumina powder and/or Tungsten powder and with λ/4 or 3λ/4 thickness epoxy matching layers. The evaluation tests were performed in pulse-echo mode, with a flat target, and in transmission/reception mode, with a calibrated PVDF hydrophone. The acoustical field emitted by each transducer was mapped in order to measure the on-axis and transverse field profiles, the aperture size and the beam spreading. The bandwidths of the transducers were determined in pulse-echo mode. Comparing the evaluation tests results of two transducers constructed with the same backing layer, the one constructed with λ/4 thickness epoxy matching layer showed better performance. The results showed that the transducers constructed with epoxy, alumina and Tungsten powders backing layers have larger bandwidth. The larger depth of field was measured for transducers constructed with epoxy and Tungsten powder backing layers. These transducers and those constructed with epoxy, Tungsten and alumina powders backing layers showed the larger field intensities in the measured transverse profiles.

  9. A dynamic calibration method for the pressure transducer

    NASA Astrophysics Data System (ADS)

    Wang, Zhongyu; Wang, Zhuoran; Li, Qiang

    2016-01-01

    Pressure transducer is widely used in the field of industry. A calibrated pressure transducer can increase the performance of precision instruments in the closed mechanical relationship. Calibration is the key to ensure the pressure transducer with a high precision and dynamic characteristic. Unfortunately, the current calibration method can usually be used in the laboratory with a good condition and only one pressure transducer can be calibrated at each time. Therefore the calibration efficiency is hard to meet the requirement of modern industry with high efficiency. A dynamic and fast calibration technology with a calibration device and a corresponding data processing method is proposed in this paper. Firstly, the pressure transducer to be calibrated is placed in the small cavity chamber. The calibration process only contains a single loop. The outputs of each calibrated transducer are recorded automatically by the control terminal. Secondly, LabView programming is used for the information acquisition and data processing. The performance of the repeatability and nonlinear indicators can be figured out directly. At last the pressure transducers are calibrated simultaneously in the experiment to verify the suggested calibration technology. The experimental result shows this method can be used to calibrate the pressure transducer in the practical engineering measurement.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. 40 CFR 1066.240 - Torque transducer verification and calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification and calibration. Calibrate torque-measurement systems as described in 40 CFR 1065.310. ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Torque transducer verification...

  12. 40 CFR 1066.240 - Torque transducer verification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Torque transducer verification. 1066... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification. Verify torque-measurement systems by performing the verifications described in §§ 1066.270...

  13. 40 CFR 1066.240 - Torque transducer verification and calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification and calibration. Calibrate torque-measurement systems as described in 40 CFR 1065.310. ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Torque transducer verification...

  14. Metal cap flexural transducers for air-coupled ultrasonics

    NASA Astrophysics Data System (ADS)

    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.

  15. NDE of interfaces in the tube geometry with piezofilm transducers

    SciTech Connect

    Hsu, D.K.; Zhang, Zhong.

    1991-01-01

    The flexible polymer piezofilms such as polyvinylidene fluoride (1) (PVDF) posses distinct advantages as ultrasonic transducers for inspecting cylindrically symmetric components, including rods, pipes, cladding, and tube interfaces. The flexibility and contour conforming nature of the film transducer ensure normal incidence and avoid mode conversion. In this work, PVDF transducers are used in the evaluation of interfaces in coaxially extruded Zirconium-Zircaloy tubes and the clamping condition of Nitinol couplers over stainless steel tubing. Detailed description will be given for the evaluation of an interface in a Zirconium-Zircaloy tube, on which the same transducer was used both as the transmitter and the receiver. The multiple echo signals were analyzed and reflection coefficient as small as 0.006 was accurately measured. Comparison will be made with the measurement results of conventional transducers. 5 refs., 6 figs.

  16. NDE of interfaces in the tube geometry with piezofilm transducers

    SciTech Connect

    Hsu, D.K.; Zhang, Zhong

    1991-12-31

    The flexible polymer piezofilms such as polyvinylidene fluoride [1] (PVDF) posses distinct advantages as ultrasonic transducers for inspecting cylindrically symmetric components, including rods, pipes, cladding, and tube interfaces. The flexibility and contour conforming nature of the film transducer ensure normal incidence and avoid mode conversion. In this work, PVDF transducers are used in the evaluation of interfaces in coaxially extruded Zirconium-Zircaloy tubes and the clamping condition of Nitinol couplers over stainless steel tubing. Detailed description will be given for the evaluation of an interface in a Zirconium-Zircaloy tube, on which the same transducer was used both as the transmitter and the receiver. The multiple echo signals were analyzed and reflection coefficient as small as 0.006 was accurately measured. Comparison will be made with the measurement results of conventional transducers. 5 refs., 6 figs.

  17. Frequency response calibration of recess-mounted pressure transducers

    NASA Technical Reports Server (NTRS)

    Marcolini, M. A.; Lorber, P. F.; Miller, W. T., Jr.; Covino, A. F., Jr.

    1991-01-01

    A technique is described for measuring the frequency response of pressure transducers mounted inside a model, where a narrow pipette leads to an orifice at the surface. An acoustic driver is mounted to a small chamber which has an opening at the opposite end with an O-ring seal to place over the orifice. A 3.18 mm (1/8 inch) reference microphone is mounted to one side of the chamber. The acoustic driver receives an input of white noise, and the transducer and reference microphone outputs are compared to obtain the frequency response of the pressure transducer. Selected results are presented in the form of power spectra for both the transducer and the reference, as well as the amplitude variation and phase shift between the two signals as a function of frequency. The effect of pipette length and the use of this technique for identifying both blocked orifices and faulty transducers are described.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  20. Piezoelectric single crystals for ultrasonic transducers in biomedical applications

    PubMed Central

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

    2014-01-01

    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

  1. Durability investigation of a group of strain gage pressure transducers

    NASA Technical Reports Server (NTRS)

    Lederer, P. S.; Hilten, J. S.

    1972-01-01

    A durability investigation was conducted on a group of eighteen bonded-wire strain gage pressure transducers with ranges of 0 to 15 psig and 0 to 100 psig using an improved version of a previously developed technique. Some of the transducers were subjected to 40 million pressure cycles at a 5-Hz rate at laboratory ambient conditions, others were cycled at a temperature of 150 F (65.6 C). The largest change in sensitivity observed was 0.22% for a 100-psig transducer subjected to 40 million pressure cycles at 150 F. The largest change in zero pressure output observed was 0.91% FS for the same transducer. None of the transducers failed completely as a result of cycling at or below full scale pressure.

  2. Embedded Ultrasonic Transducers for Active and Passive Concrete Monitoring

    PubMed Central

    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

  3. Minimally disruptive needle insertion: a biologically inspired solution.

    PubMed

    Leibinger, Alexander; Oldfield, Matthew J; Rodriguez Y Baena, Ferdinando

    2016-06-01

    The mobility of soft tissue can cause inaccurate needle insertions. Particularly in steering applications that employ thin and flexible needles, large deviations can occur between pre-operative images of the patient, from which a procedure is planned, and the intra-operative scene, where a procedure is executed. Although many approaches for reducing tissue motion focus on external constraining or manipulation, little attention has been paid to the way the needle is inserted and actuated within soft tissue. Using our biologically inspired steerable needle, we present a method of reducing the disruptiveness of insertions by mimicking the burrowing mechanism of ovipositing wasps. Internal displacements and strains in three dimensions within a soft tissue phantom are measured at the needle interface, using a scanning laser-based image correlation technique. Compared to a conventional insertion method with an equally sized needle, overall displacements and strains in the needle vicinity are reduced by 30% and 41%, respectively. The results show that, for a given net speed, needle insertion can be made significantly less disruptive with respect to its surroundings by employing our biologically inspired solution. This will have significant impact on both the safety and targeting accuracy of percutaneous interventions along both straight and curved trajectories. PMID:27274797

  4. Force modeling for needle insertion into soft tissue.

    PubMed

    Okamura, Allison M; Simone, Christina; O'Leary, Mark D

    2004-10-01

    The modeling of forces during needle insertion into soft tissue is important for accurate surgical simulation, preoperative planning, and intelligent robotic assistance for percutaneous therapies. We present a force model for needle insertion and experimental procedures for acquiring data from ex vivo tissue to populate that model. Data were collected from bovine livers using a one-degree-of-freedom robot equipped with a load cell and needle attachment. computed tomography imaging was used to segment the needle insertion process into phases identifying different relative velocities between the needle and tissue. The data were measured and modeled in three parts: 1) capsule stiffness, a nonlinear spring model; 2) friction, a modified Karnopp model; and 3) cutting, a constant for a given tissue. In addition, we characterized the effects of needle diameter and tip type on insertion force using a silicone rubber phantom. In comparison to triangular and diamond tips, a bevel tip causes more needle bending and is more easily affected by tissue density variations. Forces for larger diameter needles are higher due to increased cutting and friction forces. PMID:15490818

  5. Needle Steering in 3-D Via Rapid Replanning

    PubMed Central

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

    2014-01-01

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

  6. Design of a Slender Tuned Ultrasonic Needle for Bone Penetration

    NASA Astrophysics Data System (ADS)

    Cleary, Rebecca; Mathieson, Andrew; Wallace, Robert; Simpson, Hamish; Lucas, Margaret

    This paper reports on an ultrasonic bone biopsy needle, particularly focusing on design guidelines applicable for any slender tuned ultrasonic device component. Ultrasonic surgical devices are routinely used to cut a range of biological tissues, such as bone. However the realisation of an ultrasonic bone biopsy needle is particularly challenging. This is due to the requirement to generate sufficient vibrational amplitude capable of penetrating mineralised tissue, while avoiding flexural vibrational responses, which are known to reduce the performance and reliability of slender ultrasonic devices. This investigation uses finite element analysis (FEA) to predict the vibrational behaviour of a resonant needle which has dimensions that match closely to an 8Gx4inch bone marrow biopsy needle. Features of the needle, including changes in material and repeated changes in diameter, have been included and systematically altered to demonstrate that the location of and geometry of these features can significantly affect the resonant frequency of bending and torsional modes of vibration while having a limited effect on the frequency and shape of the tuned longitudinal mode. Experimental modal analysis was used to identify the modal parameters of the selected needle design, validating the FEA model predictions of the longitudinal mode and the close flexural modes. This verifies that modal coupling can be avoided by judicious small geometry modifications. Finally, the tuned needle assembly was driven under typical operational excitation conditions to demonstrate that an ultrasonic biopsy needle can be designed to operate in a purely longitudinal motion.

  7. 21 CFR 880.5570 - Hypodermic single lumen needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5570 Hypodermic single lumen needle. (a) Identification. A hypodermic single lumen... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hypodermic single lumen needle. 880.5570...

  8. 21 CFR 880.5570 - Hypodermic single lumen needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5570 Hypodermic single lumen needle. (a) Identification. A hypodermic single lumen... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hypodermic single lumen needle. 880.5570...

  9. 21 CFR 880.5570 - Hypodermic single lumen needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5570 Hypodermic single lumen needle. (a) Identification. A hypodermic single lumen... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hypodermic single lumen needle. 880.5570...

  10. 21 CFR 880.5570 - Hypodermic single lumen needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5570 Hypodermic single lumen needle. (a) Identification. A hypodermic single lumen... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hypodermic single lumen needle. 880.5570...

  11. MRI-Guided Vascular Access with an Active Visualization Needle

    PubMed Central

    Saikus, Christina E.; Ratnayaka, Kanishka; Barbash, Israel M.; Colyer, Jessica H.; Kocaturk, Ozgur; Faranesh, Anthony Z.; Lederman, Robert J.

    2011-01-01

    Purpose To develop an approach to vascular access under MRI, as a component of comprehensive MRI-guided cardiovascular catheterization and intervention. Materials and Methods We attempted jugular vein access in healthy pigs as a model of “difficult” vascular access. Procedures were performed under real-time MRI guidance using reduced field of view imaging. We developed an “active” MRI antenna-needle having an open-lumen, distinct tip appearance and indicators of depth and trajectory, in order to enhance MRI visibility during the procedure. We compared performance of the active needle against an unmodified commercial passively-visualized needle, measured by procedure success among operators with different levels of experience. Results MRI-guided central vein access was feasible using both the active needle and the unmodified passive needle. The active needle required less time (88 vs. 244 sec, p=0.022) and fewer needle passes (4.5 vs. 9.1, p=0.028), irrespective of operator experience. Conclusion MRI-guided access to central veins is feasible in our animal model. When image guidance is necessary for vascular access, performing this component under MRI will allow wholly MRI-guided catheterization procedures that do not require adjunctive imaging facilities such as X-ray or ultrasound. The active needle design showed enhanced visibility, as expected. These capabilities may permit more complex catheter-based cardiovascular interventional procedures enabled by enhanced image guidance. PMID:22006552

  12. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5090 Emergency airway needle....

  13. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5090 Emergency airway needle....

  14. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5090 Emergency airway needle....

  15. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5090 Emergency airway needle....

  16. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5090 Emergency airway needle....

  17. 21 CFR 880.6920 - Syringe needle introducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Syringe needle introducer. 880.6920 Section 880.6920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a...

  18. 21 CFR 880.6920 - Syringe needle introducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Syringe needle introducer. 880.6920 Section 880.6920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a...

  19. 21 CFR 880.6920 - Syringe needle introducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Syringe needle introducer. 880.6920 Section 880.6920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a...

  20. 21 CFR 880.6920 - Syringe needle introducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Syringe needle introducer. 880.6920 Section 880.6920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a...

  1. 21 CFR 880.6920 - Syringe needle introducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Syringe needle introducer. 880.6920 Section 880.6920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... that uses a spring-loaded mechanism to drive a hypodermic needle into a patient to a...

  2. 42. VALVEHOUSE FOR NEEDLE VALVE OUTLET WORKS ON GALLERY 2, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. VALVEHOUSE FOR NEEDLE VALVE OUTLET WORKS ON GALLERY 2, SHOWING OVERHEAD SERVICE CRANE AT CENTER. NOTE NEEDLE VALVE AIR VENTS AND GAUGES AT RIGHT, NEXT TO CONTROL PEDESTAL. VIEW TO EAST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  3. Synthesis of nano-crystalline multifibrous zirconia needle

    SciTech Connect

    Biswas, Mridula; Bandyopadhyay, Siddhartha

    2013-06-01

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

  4. Observations on rotating needle insertions using a brachytherapy robot

    NASA Astrophysics Data System (ADS)

    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.

  5. Needle and Syringe Cleaning Practices among Injection Drug Users.

    ERIC Educational Resources Information Center

    Fisher, Dennis G.; Harbke, Colin R.; Canty, John R.; Reynolds, Grace L.

    2002-01-01

    Evaluates the effect of needle exchange on the bleach-mediated disinfection (BMD) practices of 176 needle and syringe sharing injection drug users (IDUs). Results reveal that IDUs who traded sex for money or drugs were less likely to practice BMD, and IDUs who reported a reduced number of sex partners were more likely to practice BMD. (Contains 36…

  6. 21 CFR 878.5350 - Needle-type epilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Needle-type epilator. 878.5350 Section 878.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Therapeutic Devices § 878.5350 Needle-type...

  7. Sensorless motion planning for medical needle insertion in deformable tissues.

    PubMed

    Alterovitz, Ron; Goldberg, Kenneth Y; Pouliot, Jean; Hsu, I-Chow Joe

    2009-03-01

    Minimally invasive medical procedures such as biopsies, anesthesia drug injections, and brachytherapy cancer treatments require inserting a needle to a specific target inside soft tissues. This is difficult because needle insertion displaces and deforms the surrounding soft tissues causing the target to move during the procedure. To facilitate physician training and preoperative planning for these procedures, we develop a needle insertion motion planning system based on an interactive simulation of needle insertion in deformable tissues and numerical optimization to reduce placement error. We describe a 2-D physically based, dynamic simulation of needle insertion that uses a finite-element model of deformable soft tissues and models needle cutting and frictional forces along the needle shaft. The simulation offers guarantees on simulation stability for mesh modifications and achieves interactive, real-time performance on a standard PC. Using texture mapping, the simulation provides visualization comparable to ultrasound images that the physician would see during the procedure. We use the simulation as a component of a sensorless planning algorithm that uses numerical optimization to compute needle insertion offsets that compensate for tissue deformations. We apply the method to radioactive seed implantation during permanent seed prostate brachytherapy to minimize seed placement error. PMID:19126473

  8. Coaxial needle insertion assistant with enhanced force feedback.

    PubMed

    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

  9. Accurate localization of needle entry point in interventional MRI.

    PubMed

    Daanen, V; Coste, E; Sergent, G; Godart, F; Vasseur, C; Rousseau, J

    2000-10-01

    In interventional magnetic resonance imaging (MRI), the systems designed to help the surgeon during biopsy must provide accurate knowledge of the positions of the target and also the entry point of the needle on the skin of the patient. In some cases, this needle entry point can be outside the B(0) homogeneity area, where the distortions may be larger than a few millimeters. In that case, major correction for geometric deformation must be performed. Moreover, the use of markers to highlight the needle entry point is inaccurate. The aim of this study was to establish a three-dimensional coordinate correction according to the position of the entry point of the needle. We also describe a 2-degree of freedom electromechanical device that is used to determine the needle entry point on the patient's skin with a laser spot. PMID:11042649

  10. Limited retention of micro-organisms using commercialized needle filters.

    PubMed

    Elbaz, W; McCarthy, G; Mawhinney, T; Goldsmith, C E; Moore, J E

    2015-03-01

    A study was undertaken to compare a commercialized needle filter with a 0.2-μm filtered epidural set and a non-filtered standard needle. No culturable bacteria were detected following filtration through the 0.2-μm filter. Bacterial breakthrough was observed with the filtered needle (pore size 5 μm) and the non-filtered needle. Filtered systems (0.2 μm) should be employed to achieve total bacterial retention. This highlights that filtration systems with different pore sizes will have varying ability to retain bacteria. Healthcare professionals need to know what type/capability of filter is implied on labels used by manufacturers, and to assess whether the specification has the desired functionality to prevent bacterial translocation through needles. PMID:25618235

  11. Removal of an embedded crochet needle in the mouth

    PubMed Central

    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. PMID:26722162

  12. Modeling Electric Fields of Peripheral Nerve Block Needles.

    NASA Astrophysics Data System (ADS)

    Davis, James Ch.; Anderson, Norman E.; Meisel, Mark W.; Ramirez, Jason G.; Kayser Enneking, F.

    2006-03-01

    Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Geometric differences in the needles effect variations in their electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.

  13. Modeling Electric Fields of Peripheral Nerve Block Needles.

    NASA Astrophysics Data System (ADS)

    Davis, James Ch.; Ramirez, Jason G.

    2005-11-01

    Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Differences in geometry between needles are seen to effect changes in electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.

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

    NASA Astrophysics Data System (ADS)

    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%.

  15. Design of an Optically Controlled MR-Compatible Active Needle

    PubMed Central

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

    2015-01-01

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

  16. CUDA accelerated simulation of needle insertions in deformable tissue

    NASA Astrophysics Data System (ADS)

    Patriciu, Alexandru

    2012-10-01

    This paper presents a stiff needle-deformable tissue interaction model. The model uses a mesh-less discretization of continuum; avoiding thus the expensive remeshing required by the finite element models. The proposed model can accommodate both linear and nonlinear material characteristics. The needle-deformable tissue interaction is modeled through fundamental boundaries. The forces applied by the needle on the tissue are divided in tangent forces and constraint forces. The constraint forces are adaptively computed such that the material is properly constrained by the needle. The implementation is accelerated using NVidia CUDA. We present detailed analysis of the execution timing in both serial and parallel case. The proposed needle insertion model was integrated in a custom software that loads DICOM images, generate the deformable model, and can simulate different insertion strategies.

  17. Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles.

    PubMed

    Silva, Paula Barcellos; Krolow, Angélica Mohnsam; Pilownic, Katerine Jahnecke; Casarin, Renata Picanço; Lima, Regina Karla Pontes; Leonardo, Renato de Toledo; Pappen, Fernanda Geraldo

    2016-04-01

    This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy. PMID:27058383

  18. Optical Flow-Based Tracking of Needles and Needle-Tip Localization Using Circular Hough Transform in Ultrasound Images.

    PubMed

    Ayvali, Elif; Desai, Jaydev P

    2015-08-01

    Image-guided interventions have become the standard of care for needle-based procedures. The success of the image-guided procedures depends on the ability to precisely locate and track the needle. This work is primarily focused on 2D ultrasound-based tracking of a hollow needle (cannula) that is composed of straight segments connected by shape memory alloy actuators. An in-plane tracking algorithm based on optical flow was proposed to track the cannula configuration in real-time. Optical flow is a robust tracking algorithm that can easily run on a CPU. However, the algorithm does not perform well when it is applied to the ultrasound images directly due to the intensity variation in the images. The method presented in this work enables using the optical flow algorithm on ultrasound images to track features of the needle. By taking advantage of the bevel tip, Circular Hough transform was used to accurately locate the needle tip when the imaging is out-of-plane. Through experiments inside tissue phantom and ex-vivo experiments in bovine kidney, the success of the proposed tracking methods were demonstrated. Using the methods presented in this work, quantitative information about the needle configuration is obtained in real-time which is crucial for generating control inputs for the needle and automating the needle insertion. PMID:25503523

  19. Experimental study of needle-tissue interaction forces: effect of needle geometries, insertion methods and tissue characteristics.

    PubMed

    Jiang, Shan; Li, Pan; Yu, Yan; Liu, Jun; Yang, Zhiyong

    2014-10-17

    A thorough understanding of needle-tissue interaction mechanics is necessary to optimize needle design, achieve robotically needle steering, and establish surgical simulation system. It is obvious that the interaction is influenced by numerous variable parameters, which are divided into three categories: needle geometries, insertion methods, and tissue characteristics. A series of experiments are performed to explore the effect of influence factors (material samples n=5 for each factor) on the insertion force. Data were collected from different biological tissues and a special tissue-equivalent phantom with similar mechanical properties, using a 1-DOF mechanical testing system instrumented with a 6-DOF force/torque (F/T) sensor. The experimental results indicate that three basic phases (deformation, insertion, and extraction phase) are existent during needle penetration. Needle diameter (0.7-3.2mm), needle tip (blunt, diamond, conical, and beveled) and bevel angle (10-85°) are turned out to have a great influence on insertion force, so do the insertion velocity (0.5-10mm/s), drive mode (robot-assisted and hand-held), and the insertion process (interrupted and continuous). Different tissues such as skin, muscle, fat, liver capsule and vessel are proved to generate various force cures, which can contribute to the judgement of the needle position and provide efficient insertion strategy. PMID:25169657

  20. TRANSDUCER GENERATED ARRAYS OF ROBOTIC NANO-ARMS.

    PubMed

    Dolzhenko, Egor; Jonoska, Nataša; Seeman, Nadrian C

    2010-06-01

    We consider sets of two-dimensional arrays, called here transducer generated languages, obtained by iterative applications of transducers (finite state automata with output). Each transducer generates a set of blocks of symbols such that the bottom row of a block is an input string accepted by the transducer and, by iterative application of the transducer, each row of the block is an output of the transducer on the preceding row. We show how these arrays can be implemented through molecular assembly of triple crossover DNA molecules. Such assembly could serve as a scaffold for arranging molecular robotic arms capable for simultaneous movements. We observe that transducer generated languages define a class of languages which is a proper subclass of recognizable picture languages, but it containing the class of all factorial local two-dimensional languages. By taking the average growth rate of the number of blocks in the language as a measure of its complexity, we further observe that arrays with high complexity patterns can be generated in this way. PMID:24653669