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Sample records for accurate needle placement

  1. Improved targeting device and computer navigation for accurate placement of brachytherapy needles

    SciTech Connect

    Pappas, Ion P.I.; Ryan, Paul; Cossmann, Peter; Kowal, Jens; Borgeson, Blake; Caversaccio, Marco

    2005-06-15

    Successful treatment of skull base tumors with interstitial brachytherapy requires high targeting accuracy for the brachytherapy needles to avoid harming vital anatomical structures. To enable safe placement of the needles in this area, we developed an image-based planning and navigation system for brachytherapy, which includes a custom-made mechanical positioning arm that allows rough and fine adjustment of the needle position. The fine-adjustment mechanism consists of an XYZ microstage at the base of the arm and a needle holder with two fine-adjustable inclinations. The rotation axes of the inclinations cross at the tip of the needle so that the inclinational adjustments do not interfere with the translational adjustments. A vacuum cushion and a noninvasive fixation frame are used for the head immobilization. To avoid mechanical bending of the needles due to the weight of attached tracking markers, which would be detrimental for targeting accuracy, only a single LED marker on the tail of the needle is used. An experimental phantom-based targeting study with this setup demonstrated that a positioning accuracy of 1.4 mm (rms) can be achieved. The study showed that the proposed setup allows brachytherapy needles to be easily aligned and inserted with high targeting accuracy according to a preliminary plan. The achievable accuracy is higher than if the needles are inserted manually. The proposed system can be linked to a standard afterloader and standard dosimetry planning module. The associated additional effort is reasonable for the clinical practice and therefore the proposed procedure provides a promising tool for the safe treatment of tumors in the skull base area.

  2. Percutaneous Radiofrequency Ablation of Osteoid Osteomas with Use of Real-Time Needle Guidance for Accurate Needle Placement: A Pilot Study

    SciTech Connect

    Busser, Wendy M. H. Hoogeveen, Yvonne L.; Veth, Rene P. H.; Schreuder, H. W. Bart; Balguid, Angelique; Renema, W. KlaasJan; SchultzeKool, Leo J.

    2011-02-15

    Purpose: To evaluate the accuracy and technical success of positioning a radiofrequency ablation (RFA) electrode in osteoid osteomas by use of a new real-time needle guidance technology combining cone-beam computed tomography (CT) and fluoroscopy. Materials and Methods: Percutaneous RFA of osteoid osteomas was performed in five patients (median age 18 years), under general anesthesia, with the use of cone-beam CT and fluoroscopic guidance for electrode positioning. The outcome parameters were technical success, meaning correct needle placement in the nidus; accuracy defined as the deviation (in mm) from the center of the nidus; and clinical outcome at follow-up. Results: In all five cases, positioning was possible within 3 mm of the determined target location (median nidus size 6.8 mm; range 5-10.2 mm). All procedures were technically successful. All patients were free of pain at clinical follow-up. No complications were observed. Conclusion: Real-time fluoroscopy needle guidance based on cone-beam CT is a useful tool to accurately position radiofrequency needles for minimally invasive treatment of osteoid osteomas.

  3. MRI-Compatible Pneumatic Robot for Transperineal Prostate Needle Placement.

    PubMed

    Fischer, Gregory S; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; Dimaio, Simon P; Tempany, Clare M; Hata, Nobuhiko; Fichtinger, Gabor

    2008-06-01

    Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of high-field (1.5T or greater) MRI. The inability to use conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intraprostatic needle placement inside closed high-field MRI scanners. MRI compatibility of the robot has been evaluated under 3T MRI using standard prostate imaging sequences and average SNR loss is limited to 5%. Needle alignment accuracy of the robot under servo pneumatic control is better than 0.94 mm rms per axis. The complete system workflow has been evaluated in phantom studies with accurate visualization and targeting of five out of five 1 cm targets. The paper explains the robot mechanism and controller design, the system integration, and presents results of preliminary evaluation of the system. PMID:21057608

  4. MRI-Compatible Pneumatic Robot for Transperineal Prostate Needle Placement

    PubMed Central

    Fischer, Gregory S.; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; DiMaio, Simon P.; Tempany, Clare M.; Hata, Nobuhiko; Fichtinger, Gabor

    2010-01-01

    Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of high-field (1.5T or greater) MRI. The inability to use conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intraprostatic needle placement inside closed high-field MRI scanners. MRI compatibility of the robot has been evaluated under 3T MRI using standard prostate imaging sequences and average SNR loss is limited to 5%. Needle alignment accuracy of the robot under servo pneumatic control is better than 0.94 mm rms per axis. The complete system workflow has been evaluated in phantom studies with accurate visualization and targeting of five out of five 1 cm targets. The paper explains the robot mechanism and controller design, the system integration, and presents results of preliminary evaluation of the system. PMID:21057608

  5. Treatment planning for prostate focal laser ablation in the face of needle placement uncertainty

    SciTech Connect

    Cepek, Jeremy Fenster, Aaron; Lindner, Uri; Trachtenberg, John; Davidson, Sean R. H.; Haider, Masoom A.; Ghai, Sangeet

    2014-01-15

    Purpose: To study the effect of needle placement uncertainty on the expected probability of achieving complete focal target destruction in focal laser ablation (FLA) of prostate cancer. Methods: Using a simplified model of prostate cancer focal target, and focal laser ablation region shapes, Monte Carlo simulations of needle placement error were performed to estimate the probability of completely ablating a region of target tissue. Results: Graphs of the probability of complete focal target ablation are presented over clinically relevant ranges of focal target sizes and shapes, ablation region sizes, and levels of needle placement uncertainty. In addition, a table is provided for estimating the maximum target size that is treatable. The results predict that targets whose length is at least 5 mm smaller than the diameter of each ablation region can be confidently ablated using, at most, four laser fibers if the standard deviation in each component of needle placement error is less than 3 mm. However, targets larger than this (i.e., near to or exceeding the diameter of each ablation region) require more careful planning. This process is facilitated by using the table provided. Conclusions: The probability of completely ablating a focal target using FLA is sensitive to the level of needle placement uncertainty, especially as the target length approaches and becomes greater than the diameter of ablated tissue that each individual laser fiber can achieve. The results of this work can be used to help determine individual patient eligibility for prostate FLA, to guide the planning of prostate FLA, and to quantify the clinical benefit of using advanced systems for accurate needle delivery for this treatment modality.

  6. Three-dimensional ultrasound-guided robotic needle placement: an experimental evaluation

    PubMed Central

    Boctor, Emad M.; Choti, Michael A.; Burdette, Everette C.; Webster III, Robert J.

    2014-01-01

    Background Clinical use of image-guided needle placement robots has lagged behind laboratory-demonstrated robotic capability. Bridging this gap requires reliable and easy-to-use robotic systems. Methods Our system for image-guided needle placement requires only simple, low-cost components and minimal, entirely off-line calibration. It rapidly aligns needles to planned entry paths using 3D ultrasound (US) reconstructed from freehand 2D scans. We compare system accuracy against clinical standard manual needle placement. Results The US-guided robotic system is significantly more accurate than single manual insertions. When several manual withdrawals and reinsertions are allowed, accuracy becomes equivalent. In ex vivo experiments, robotic repeatability was 1.56 mm, compared to 3.19 and 4.63 mm for two sets of manual insertions. In an in vivo experiment with heartbeat and respiratory effects, robotic system accuracy was 5.5 mm. Conclusions A 3D US-guided robot can eliminate error bias and reduce invasiveness (the number of insertions required) compared to manual needle insertion. Remaining future challenges include target motion compensation. PMID:18433079

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  8. 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

  9. Is a Writing Sample Necessary for "Accurate Placement"?

    ERIC Educational Resources Information Center

    Sullivan, Patrick; Nielsen, David

    2009-01-01

    The scholarship about assessment for placement is extensive and notoriously ambiguous. Foremost among the questions that continue to be unresolved in this scholarship is this one: Is a writing sample necessary for "accurate placement"? Using a robust data sample of student assessment essays and ACCUPLACER test scores, we put this question to the…

  10. Targeting Error Simulator for Image-guided Prostate Needle Placement

    PubMed Central

    Lasso, Andras; Avni, Shachar; Fichtinger, Gabor

    2010-01-01

    Motivation Needle-based biopsy and local therapy of prostate cancer depend multimodal imaging for both target planning and needle guidance. The clinical process involves selection of target locations in a pre-operative image volume and registering these to an intra-operative volume. Registration inaccuracies inevitably lead to targeting error, a major clinical concern. The analysis of targeting error requires a large number of images with known ground truth, which has been infeasible even for the largest research centers. Methods We propose to generate realistic prostate imaging data in a controllable way, with known ground truth, by simulation of prostate size, shape, motion and deformation typically encountered in prostatic needle placement. This data is then used to evaluate a given registration algorithm, by testing its ability to reproduce ground truth contours, motions and deformations. The method builds on statistical shape atlas to generate large number of realistic prostate shapes and finite element modeling to generate high-fidelity deformations, while segmentation error is simulated by warping the ground truth data in specific prostate regions. Expected target registration error (TRE) is computed as a vector field. Results The simulator was configured to evaluate the TRE when using a surface-based rigid registration algorithm in a typical prostate biopsy targeting scenario. Simulator parameters, such as segmentation error and deformation, were determined by measurements in clinical images. Turnaround time for the full simulation of one test case was below 3 minutes. The simulator is customizable for testing, comparing, optimizing segmentation and registration methods and is independent of the imaging modalities used. PMID:21096275

  11. Needle placement for piriformis injection using 3-D imaging.

    PubMed

    Clendenen, Steven R; Candler, Shawn A; Osborne, Michael D; Palmer, Scott C; Duench, Stephanie; Glynn, Laura; Ghazi, Salim M

    2013-01-01

    Piriformis syndrome is a pain syndrome originating in the buttock and is attributed to 6% - 8% of patients referred for the treatment of back and leg pain. The treatment for piriformis syndrome using fluoroscopy, computed tomography (CT), electromyography (EMG), and ultrasound (US) has become standard practice. The treatment of Piriformis Syndrome has evolved to include fluoroscopy and EMG with CT guidance. We present a case study of 5 successful piriformis injections using 3-D computer-assisted electromagnet needle tracking coupled with ultrasound. A 6-degree of freedom electromagnetic position tracker was attached to the ultrasound probe that allowed the system to detect the position and orientation of the probe in the magnetic field. The tracked ultrasound probe was used to find the posterior superior iliac spine. Subsequently, 3 points were captured to register the ultrasound image with the CT or magnetic resonance image scan. Moreover, after the registration was obtained, the navigation system visualized the tracked needle relative to the CT scan in real-time using 2 orthogonal multi-planar reconstructions centered at the tracked needle tip. Conversely, a recent study revealed that fluoroscopically guided injections had 30% accuracy compared to ultrasound guided injections, which tripled the accuracy percentage. This novel technique exhibited an accurate needle guidance injection precision of 98% while advancing to the piriformis muscle and avoiding the sciatic nerve. The mean (± SD) procedure time was 19.08 (± 4.9) minutes. This technique allows for electromagnetic instrument tip tracking with real-time 3-D guidance to the selected target. As with any new technique, a learning curve is expected; however, this technique could offer an alternative, minimizing radiation exposure. PMID:23703429

  12. Optimal Needle Placement for Extensor Hallucis Longus Muscle: A Cadaveric Study

    PubMed Central

    2016-01-01

    Objective To determine the midpoint (MD) of extensor hallucis longus muscle (EHL) and compare the accuracy of different needle electromyography (EMG) insertion techniques through cadaver dissection. Methods Thirty-eight limbs of 19 cadavers were dissected. The MD of EHL was marked at the middle of the musculotendinous junction and proximal origin of EHL. Three different needle insertion points of EHL were marked following three different textbooks: M1, 3 fingerbreadths above bimalleolar line (BML); M2, junction between the middle and lower third of tibia; M3, 15 cm proximal to the lower border of both malleoli. The distance from BML to MD (BML_MD), and the difference between 3 different points (M1–3) and MD were measured (designated D1, D2, and D3, respectively). The lower leg length (LL) was measured from BML to top of medial condyle of tibia. Results The median value of LL was 34.5 cm and BML_MD was 12.0 cm. The percentage of BML_MD to LL was 35.1%. D1, D2, and D3 were 7.0, 0.9, and 3.0 cm, respectively. D2 was the shortest, meaning needle placement following technique by Lee and DeLisa was closest to the actual midpoint of EHL. Conclusion The MD of EHL is approximately 12 cm above BML, and about distal 35% of lower leg length. Technique that recommends placing the needle at distal two-thirds of the lower leg (M2) is the most accurate method since the point was closest to muscle belly of EHL.

  13. A new device for stereotactic CT-guided biopsy of the canine brain: design, construction, and needle placement accuracy.

    PubMed

    Giroux, Alain; Jones, Jeryl C; Bøhn, Jan Helge; Duncan, Robert B; Waldron, Don R; Inzana, Karen R

    2002-01-01

    An inexpensive device was created for computed tomographic (CT)-guided stereotactic biopsy of the canine brain. The accuracy of the device was tested using 16, formalin-perfused, canine head specimens. For each dog, a 6-inch biopsy needle was guided into pituitary gland and caudate nucleus targets. Needle tracks were measured using the CT computer and infused with tissue staining solution. Hit success and actual needle track lengths were determined from sliced brain specimens. The device enabled accurate orientation and placement of the canine head in the slice plane, such that progressive penetration of the biopsy needle could be monitored. The caudate nucleus was hit 12/16 times (75% accuracy) and the pituitary gland 15.5/16 times (98.6% accuracy). Hit proportions for the two targets did not differ (P < 0.05). A significant difference was found between CT and actual track length for both targets (P < 0.01). This was attributed to incomplete staining of the bevel portion of the needle track. PMID:12088316

  14. Experimental platform for intra-uterine needle placement procedures

    NASA Astrophysics Data System (ADS)

    Madjidi, Yashar; Haidegger, Tamás.; Ptacek, Wolfgang; Berger, Daniel; Kirisits, Christian; Kronreif, Gernot; Fichtinger, Gabor

    2013-03-01

    A framework has been investigated to enable a variety of comparative studies in the context of needle-based gynaecological brachytherapy. Our aim was to create an anthropomorphic phantom-based platform. The three main elements of the platform are the organ model, needle guide, and needle drive. These have been studied and designed to replicate the close environment of brachytherapy treatment for cervical cancer. Key features were created with the help of collaborating interventional radio-oncologists and the observations made in the operating room. A phantom box, representing the uterus model, has been developed considering available surgical analogies and operational limitations, such as organs at risk. A modular phantom-based platform has been designed and prototyped with the capability of providing various boundary conditions for the target organ. By mimicking the female pelvic floor, this framework has been used to compare a variety of needle insertion techniques and configurations for cervical and uterine interventions. The results showed that the proposed methodology is useful for the investigation of quantifiable experiments in the intraabdominal and pelvic regions.

  15. Feasibility Study of Needle Placement in Percutaneous Vertebroplasty: Cone-Beam Computed Tomography Guidance Versus Conventional Fluoroscopy

    SciTech Connect

    Braak, Sicco J.; Zuurmond, Kirsten Aerts, Hans C. J.; Leersum, Marc van Overtoom, Timotheus T. Th. Heesewijk, Johannes P. M. van Strijen, Marco J. L. van

    2013-08-01

    ObjectiveTo investigate the accuracy, procedure time, fluoroscopy time, and dose area product (DAP) of needle placement during percutaneous vertebroplasty (PVP) using cone-beam computed tomography (CBCT) guidance versus fluoroscopy.Materials and MethodsOn 4 spine phantoms with 11 vertebrae (Th7-L5), 4 interventional radiologists (2 experienced with CBCT guidance and two inexperienced) punctured all vertebrae in a bipedicular fashion. Each side was randomization to either CBCT guidance or fluoroscopy. CBCT guidance is a sophisticated needle guidance technique using CBCT, navigation software, and real-time fluoroscopy. The placement of the needle had to be to a specific target point. After the procedure, CBCT was performed to determine the accuracy, procedure time, fluoroscopy time, and DAP. Analysis of the difference between methods and experience level was performed.ResultsMean accuracy using CBCT guidance (2.61 mm) was significantly better compared with fluoroscopy (5.86 mm) (p < 0.0001). Procedure time was in favor of fluoroscopy (7.39 vs. 10.13 min; p = 0.001). Fluoroscopy time during CBCT guidance was lower, but this difference is not significant (71.3 vs. 95.8 s; p = 0.056). DAP values for CBCT guidance and fluoroscopy were 514 and 174 mGy cm{sup 2}, respectively (p < 0.0001). There was a significant difference in favor of experienced CBCT guidance users regarding accuracy for both methods, procedure time of CBCT guidance, and added DAP values for fluoroscopy.ConclusionCBCT guidance allows users to perform PVP more accurately at the cost of higher patient dose and longer procedure time. Because procedural complications (e.g., cement leakage) are related to the accuracy of the needle placement, improvements in accuracy are clinically relevant. Training in CBCT guidance is essential to achieve greater accuracy and decrease procedure time/dose values.

  16. Using an abdominal phantom to teach urology residents ultrasound-guided percutaneous needle placement

    PubMed Central

    Filippou, Pauline; Odisho, Anobel; Ramaswamy, Krishna; Usawachintachit, Manint; Hu, Weiguo; Li, Jianxing; Chi, Thomas

    2016-01-01

    ABSTRACT Introduction: To assess the effect of a hands-on ultrasound training session to teach urologic trainees ultrasound-guided percutaneous needle placement. Materials and methods: University of California, San Francisco (UCSF) urology residents completed a time trial, placing a needle into a phantom model target under ultrasound guidance. Participants were randomized into three educational exposure groups: Group 1's time trial occurred prior to any teaching intervention, group 2's after experiencing a hands-on training module, and group 3's after exposure to both the training module and one-on-one attending feedback. Needle placement speed and accuracy as well as trainees' perceived confidence in utilizing ultrasound were measured. Results: The study cohort consisted of 15 resident trainees. Seven were randomized to group 1, three to group 2, and five to group 3. All residents reported minimal prior ultrasound experience. Their confidence in using ultrasound improved significantly after completing the training module with the most significant improvement seen among junior residents. Time to needle placement was fastest after receiving attending feedback (46.6sec in group 3 vs. 82.7sec in groups 1 and 2, p<0.01). Accuracy also improved with attending feedback, though the number of repositioning attempts did not differ significantly between groups. Conclusions: A hands-on training module and use of an abdominal phantom trainer increased resident confidence and skill in their use of ultrasound to guide percutaneous needle positioning. Attending feedback is critical for improving accuracy in needle guidance toward a target. Ultrasound-guided needle positioning is a teachable skill and can be applicable to multiple urologic procedures. PMID:27564282

  17. Pneumatically Operated MRI-Compatible Needle Placement Robot for Prostate Interventions

    PubMed Central

    Fischer, Gregory S.; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; Mewes, Philip W.; Tempany, Clare M.; Hata, Nobuhiko; Fichtinger, Gabor

    2011-01-01

    Magnetic Resonance Imaging (MRI) has potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. The strong magnetic field prevents the use of conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intra-prostatic needle placement inside closed high-field MRI scanners. The robot performs needle insertion under real-time 3T MR image guidance; workspace requirements, MR compatibility, and workflow have been evaluated on phantoms. The paper explains the robot mechanism and controller design and presents results of preliminary evaluation of the system. PMID:21686038

  18. Preclinical evaluation of an MRI-compatible pneumatic robot for angulated needle placement in transperineal prostate interventions

    PubMed Central

    Tokuda, Junichi; Song, Sang-Eun; Fischer, Gregory S.; Iordachita, Iulian; Seifabadi, Reza; Cho, Bong Joon; Tuncali, Kemal; Fichtinger, Gabor; Tempany, Clare M.; Hata, Nobuhiko

    2013-01-01

    Purpose To evaluate the targeting accuracy of a small profile MRI-compatible pneumatic robot for needle placement that can angulate a needle insertion path into a large accessible target volume. Methods We extended our MRI-compatible pneumatic robot for needle placement to utilize its four degrees-of-freedom (4-DOF) mechanism with two parallel triangular structures and support transperineal prostate biopsies in a closed-bore magnetic resonance imaging (MRI) scanner. The robot is designed to guide a needle towards a lesion so that a radiologist can manually insert it in the bore. The robot is integrated with navigation software that allows an operator to plan angulated needle insertion by selecting a target and an entry point. The targeting error was evaluated while the angle between the needle insertion path and the static magnetic field was between −5.7° and 5.7° horizontally and between −5.7° and 4.3° vertically in the MRI scanner after sterilizing and draping the device. Results The robot positioned the needle for angulated insertion as specified on the navigation software with overall targeting error of 0.8 ± 0.5 mm along the horizontal axis and 0.8 ± 0.8 mm along the vertical axis. The two-dimensional root-mean-square targeting error on the axial slices as containing the targets was 1.4 mm. Conclusions Our preclinical evaluation demonstrated that the MRI-compatible pneumatic robot for needle placement with the capability to angulate the needle insertion path provides targeting accuracy feasible for clinical MRI-guided prostate interventions. The clinical feasibility has to be established in a clinical study. PMID:22678723

  19. Virtobot 2.0: the future of automated surface documentation and CT-guided needle placement in forensic medicine.

    PubMed

    Ebert, Lars Christian; Ptacek, Wolfgang; Breitbeck, Robert; Fürst, Martin; Kronreif, Gernot; Martinez, Rosa Maria; Thali, Michael; Flach, Patricia M

    2014-06-01

    In this paper we present the second prototype of a robotic system to be used in forensic medicine. The system is capable of performing automated surface documentation using photogrammetry, optical surface scanning and image-guided, post-mortem needle placement for tissue sampling, liquid sampling, or the placement of guide wires. The upgraded system includes workflow optimizations, an automatic tool-change mechanism, a new software module for trajectory planning and a fully automatic computed tomography-data-set registration algorithm. We tested the placement accuracy of the system by using a needle phantom with radiopaque markers as targets. The system is routinely used for surface documentation and resulted in 24 surface documentations over the course of 11 months. We performed accuracy tests for needle placement using a biopsy phantom, and the Virtobot placed introducer needles with an accuracy of 1.4 mm (±0.9 mm). The second prototype of the Virtobot system is an upgrade of the first prototype but mainly focuses on streamlining the workflow and increasing the level of automation and also has an easier user interface. These upgrades make the Virtobot a potentially valuable tool for case documentation in a scalpel-free setting that uses purely imaging techniques and minimally invasive procedures and is the next step toward the future of virtual autopsy. PMID:24474435

  20. Detection of intraneural needle-placement with multiple frequency bioimpedance monitoring: a novel method.

    PubMed

    Kalvøy, Håvard; Sauter, Axel R

    2016-04-01

    Electrical impedance measurements have been used to detect intraneural needle placement, but there is still a lack of precision with this method. The purpose of the study was to develop a method for the discrimination of nerve tissue from other tissue types based on multiple frequency impedance measurements. Impedance measurements with 25 different frequencies between 1.26 and 398 kHz were obtained in eight pigs while placing the tip of a stimulation needle within the sciatic nerve and in other tissues. Various impedance variables and measurement frequencies were tested for tissue discrimination. Best tissue discrimination was obtained by using three different impedance parameters with optimal measurement frequencies: Modulus (126 kHz), Phase angle (40 kHz) and the Delta of the phase angle (between 126 and 158 kHz). These variables were combined in a Compound variable C. The area under the curve in a receiver operating characteristic was consecutively increased for the Modulus (78 %), Phase angle (86 %), Delta of the phase angle (94 %), and the Compound variable C (97 %), indicating highest specificity and sensitivity for C. An algorithm based on C was implemented in a real-time feasibility test and used in an additional test animal to demonstrate our new method. Discrimination between nerve tissue and other tissue types was improved by combining several impedance variables at multiple measurement frequencies. PMID:25902898

  1. Accurate biopsy-needle depth estimation in limited-angle tomography using multi-view geometry

    NASA Astrophysics Data System (ADS)

    van der Sommen, Fons; Zinger, Sveta; de With, Peter H. N.

    2016-03-01

    Recently, compressed-sensing based algorithms have enabled volume reconstruction from projection images acquired over a relatively small angle (θ < 20°). These methods enable accurate depth estimation of surgical tools with respect to anatomical structures. However, they are computationally expensive and time consuming, rendering them unattractive for image-guided interventions. We propose an alternative approach for depth estimation of biopsy needles during image-guided interventions, in which we split the problem into two parts and solve them independently: needle-depth estimation and volume reconstruction. The complete proposed system consists of the previous two steps, preceded by needle extraction. First, we detect the biopsy needle in the projection images and remove it by interpolation. Next, we exploit epipolar geometry to find point-to-point correspondences in the projection images to triangulate the 3D position of the needle in the volume. Finally, we use the interpolated projection images to reconstruct the local anatomical structures and indicate the position of the needle within this volume. For validation of the algorithm, we have recorded a full CT scan of a phantom with an inserted biopsy needle. The performance of our approach ranges from a median error of 2.94 mm for an distributed viewing angle of 1° down to an error of 0.30 mm for an angle larger than 10°. Based on the results of this initial phantom study, we conclude that multi-view geometry offers an attractive alternative to time-consuming iterative methods for the depth estimation of surgical tools during C-arm-based image-guided interventions.

  2. Intraprocedural Diffusion-Weighted PROPELLER MRI to Guide Percutaneous Biopsy Needle Placement within Rabbit VX2 Liver Tumors

    PubMed Central

    Deng, Jie; Virmani, Sumeet; Yang, Guang-Yu; Tang, Richard; Woloschak, Gayle; Omary, Reed A.; Larson, Andrew C.

    2010-01-01

    Purpose To test the hypothesis that diffusion-weighted (DW)-PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) magnetic resonance imaging (MRI) can be used to guide biopsy needle placement during percutaneous interventional procedures to selectively target viable and necrotic tissues within VX2 rabbit liver tumors. Materials and Methods Our institutional Animal Care and Use Committee approved all experiments. In six rabbits implanted with 15 VX2 liver tumors, baseline DWPROPELLER images acquired prior to the interventional procedure were used for apparent diffusion coefficient (ADC) measurements. Next, intraprocedural DW-PROPELLER scans were performed with needle position iteratively adjusted to target viable, necrotic, or intermediate border tissue regions. DW-PROPELLER ADC measurements at the selected needle tip locations were compared with the percentage of tumor necrosis qualitatively assessed at histopathology. Results DW-PROPELLER images demonstrated intratumoral tissue heterogeneity and clearly depicted the needle tip position within viable and necrotic tumor tissues. Mean ADC measurements within the region-of-interest encompassing the needle tip were highly correlated with histopathologic tumor necrotic tissue assessments. Conclusion DW-PROPELLER is an effective method to selectively position the biopsy needle tip within viable and necrotic tumor tissues. The DW-PROPELLER method may offer an important complementary tool for functional guidance during MR-guided percutaneous procedures. PMID:19629976

  3. Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

    SciTech Connect

    Cornelis, F.; Takaki, H.; Laskhmanan, M.; Durack, J. C.; Erinjeri, J. P.; Getrajdman, G. I.; Maybody, M.; Sofocleous, C. T.; Solomon, S. B.; Srimathveeravalli, G.

    2015-10-15

    PurposeTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.

  4. Precision grid and hand motion for accurate needle insertion in brachytherapy

    SciTech Connect

    McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J.

    2011-08-15

    Purpose: In prostate brachytherapy, a grid is used to guide a needle tip toward a preplanned location within the tissue. During insertion, the needle deflects en route resulting in target misplacement. In this paper, 18-gauge needle insertion experiments into phantom were performed to test effects of three parameters, which include the clearance between the grid hole and needle, the thickness of the grid, and the needle insertion speed. Measurement apparatus that consisted of two datum surfaces and digital depth gauge was developed to quantify needle deflections. Methods: The gauge repeatability and reproducibility (GR and R) test was performed on the measurement apparatus, and it proved to be capable of measuring a 2 mm tolerance from the target. Replicated experiments were performed on a 2{sup 3} factorial design (three parameters at two levels) and analysis included averages and standard deviation along with an analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: Results showed that grid with tight clearance hole and slow needle speed increased precision and accuracy of needle insertion. The tight grid was vital to enhance precision and accuracy of needle insertion for both slow and fast insertion speed; additionally, at slow speed the tight, thick grid improved needle precision and accuracy. Conclusions: In summary, the tight grid is important, regardless of speed. The grid design, which shows the capability to reduce the needle deflection in brachytherapy procedures, can potentially be implemented in the brachytherapy procedure.

  5. Effect of scattered and discrete hydramethylnon bait placement on the Asian needle ant.

    PubMed

    Rice, Eleanor Spicer; Shik, Jonathan Z; Silverman, Jules

    2012-10-01

    The Asian needle ant (Pachycondyla chinensis Emery) is invading natural and disturbed habitats across the eastern United States. While recent studies document the impact of P. chinensis on native ecosystems and human health, effective control measures remain unknown. Thus, we evaluated the field performance of a hydramethylnon granular bait, Maxforce Complete Granular Insect Bait, dispersed in clumps or scattered against P. chinensis. We also measured the effect of this bait on P. chinensis outside of the treatment zone. Surprisingly, unlike reports for other ant species, we achieved nearly complete P. chinensis population reductions 1 d after treatments were applied. Significant ant reductions were achieved until the end of our study at 28 d. No difference was recorded between clumped and scattered application methods. We found no overall difference in ant reductions from the edge out to 5 m beyond the treatment zone. Other local ant species appeared to be unaffected by the bait and foraging activity increased slightly after P. chinensis removal from treated areas. We suggest that Maxforce Complete Granular Insect Bait can be effective in an Asian needle ant treatment program. PMID:23156173

  6. Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

    NASA Astrophysics Data System (ADS)

    Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

    2015-10-01

    Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

  7. Can problematic fibroepithelial lesions be accurately classified on core needle biopsies?

    PubMed

    Bandyopadhyay, Sudeshna; Barak, Stephanie; Hayek, Kinda; Thomas, Sumi; Saeed, Haleema; Beydoun, Rafic; Shi, Dongping; Arabi, Haitham; Ruterbusch, Julie; Cote, Michele; Ali-Fehmi, Rouba

    2016-01-01

    Fibroepithelial lesions (FEL) of the breast are notoriously difficult to classify on core needle biopsies. The goal of this study was to evaluate interobserver variability and accuracy of subclassifying difficult FELs into fibroadenoma (FA) and phyllodes tumors (PTs). We identified 50 breast core needle biopsies, initially diagnosed generically as FEL, with subsequent excision and final diagnosis of either FA or benign PT. Five surgical pathologists from one institution independently reviewed these in 3 rounds. The pathologists were blinded to the final excisional diagnosis. Two diagnostic categories were allowed: FA and PT. A set of histologic criteria was provided including the presence of subepithelial condensation, stromal heterogeneity, overgrowth, pleomorphism, fragmentation, cellularity, adipose tissue entrapment, and mitotic count and asked to review the slides for the second round. A third round of interpretations was conducted after each criterion was defined. Interobserver agreement for the diagnosis and each criterion was evaluated using the κ level of agreement. Accuracy of ratings to final diagnosis was calculated using Wilcoxon signed-rank test. κ Values for interobserver agreement were fair for the first and second rounds varying from 0.20 to 0.22, respectively. This increased to 0.27 in round 3. When considering each category, the κ value varied from 0.26 to 0.29 for FA and 0.28 to 0.14 for PT. Overall, there was fair agreement between the pathologists in all categories. The rate of correctly diagnosed cases ranged from 40% in the first round, to 48% in the second round, to 67% in round 3. Overall the pathologists performed better in identifying FA than PT. The accuracy of interpretations was significantly different between the first (40%), second (48%), and third rounds (67%). PMID:26521710

  8. Are School Placement Recommendations Accurate? The Effect of Students' Ethnicity on Teachers' Judgments and Recognition Memory

    ERIC Educational Resources Information Center

    Glock, Sabine; Krolak-Schwerdt, Sabine; Pit-ten Cate, Ineke M.

    2015-01-01

    Educational research has provided evidence that racial and ethnic minority students are disadvantaged in today's educational systems. Teachers' stereotypical expectations are believed to contribute to these disadvantages because teachers make decisions about grades, special education, tracking, and school placement. Research so far has shown that…

  9. 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

  10. Finite element analysis of the effect of electrodes placement on accurate resistivity measurement in a diamond anvil cell with van der Pauw technique

    SciTech Connect

    Wu Baojia; Huang Xiaowei; Han Yonghao; Gao Chunxiao; Peng Gang; Liu Cailong; Wang Yue; Cui Xiaoyan; Zou Guangtian

    2010-05-15

    The van der Pauw technique is widely used to determine resistivity of materials. In diamond anvil cell the compressed sample will make the contact placement change under high pressure. Using finite element analysis, we study the effect of contact placement error induced by pressure on the resistivity measurement accuracy of van der Pauw method. The results show the contact placement has a significant effect on determination accuracy. This method can provide accurate determination of sample resistivity when the spacing b between the contact center and sample periphery is less than D/9 (sample diameter). And the effect of contact placement error on accuracy rapidly increases as the contact location is closing to the sample center. For the same contact placement, the contact size error has a more obvious effect on the semiconductor sample.

  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. Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images

    PubMed Central

    Vrooijink, Gustaaf J.; Abayazid, Momen; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2015-01-01

    Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600

  13. Cone beam CT guidance provides superior accuracy for complex needle paths compared with CT guidance

    PubMed Central

    Braak, S J; Fütterer, J J; van Strijen, M J L; Hoogeveen, Y L; de Lange, F; Schultze Kool, L J

    2013-01-01

    Objective: To determine the accuracy of cone beam CT (CBCT) guidance and CT guidance in reaching small targets in relation to needle path complexity in a phantom. Methods: CBCT guidance combines three-dimensional CBCT imaging with fluoroscopy overlay and needle planning software to provide real-time needle guidance. The accuracy of needle positioning, quantified as deviation from a target, was assessed for inplane, angulated and double angulated needle paths. Four interventional radiologists reached four targets along the three paths using CBCT and CT guidance. Accuracies were compared between CBCT and CT for each needle path and between the three approaches within both modalities. The effect of user experience in CBCT guidance was also assessed. Results: Accuracies for CBCT were significantly better than CT for the double angulated needle path (2.2 vs 6.7 mm, p<0.001) for all radiologists. CBCT guidance showed no significant differences between the three approaches. For CT, deviations increased with increasing needle path complexity from 3.3 mm for the inplane placements to 4.4 mm (p=0.007) and 6.7 mm (p<0.001) for the angulated and double angulated CT-guided needle placements, respectively. For double angulated needle paths, experienced CBCT users showed consistently higher accuracies than trained users [1.8 mm (range 1.2–2.2) vs 3.3 mm (range 2.1–7.2) deviation from target, respectively; p=0.003]. Conclusion: In terms of accuracy, CBCT is the preferred modality, irrespective of the level of user experience, for more difficult guidance procedures requiring double angulated needle paths as in oncological interventions. Advances in knowledge: Accuracy of CBCT guidance has not been discussed before. CBCT guidance allows accurate needle placement irrespective of needle path complexity. For angulated and double-angulated needle paths, CBCT is more accurate than CT guidance. PMID:23913308

  14. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

    PubMed Central

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

    2014-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0–10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

  15. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement.

    PubMed

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S

    2013-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0-10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

  16. A model to predict deflection of bevel-tipped active needle advancing in soft tissue.

    PubMed

    Datla, Naresh V; Konh, Bardia; Honarvar, Mohammad; Podder, Tarun K; Dicker, Adam P; Yu, Yan; Hutapea, Parsaoran

    2014-03-01

    Active needles are recently being developed to improve steerability and placement accuracy for various medical applications. These active needles can bend during insertion by actuators attached to their bodies. The bending of active needles enables them to be steered away from the critical organs on the way to target and accurately reach target locations previously unachievable with conventional rigid needles. These active needles combined with an asymmetric bevel-tip can further improve their steerability. To optimize the design and to develop accurate path planning and control algorithms, there is a need to develop a tissue-needle interaction model. This work presents an energy-based model that predicts needle deflection of active bevel-tipped needles when inserted into the tissue. This current model was based on an existing energy-based model for bevel-tipped needles, to which work of actuation was included in calculating the system energy. The developed model was validated with needle insertion experiments with a phantom material. The model predicts needle deflection reasonably for higher diameter needles (11.6% error), whereas largest error was observed for the smallest needle diameter (24.7% error). PMID:24296105

  17. Biomechanics-Based Curvature Estimation for Ultrasound-guided Flexible Needle Steering in Biological Tissues.

    PubMed

    Moreira, Pedro; Misra, Sarthak

    2015-08-01

    Needle-based procedures are commonly performed during minimally invasive surgery for treatment and diagnosis. Accurate needle tip placement is important for the success of the procedures. Misplacement of the needle tip might cause unsuccessful treatment or misdiagnosis. Robot-assisted needle insertion systems have been developed in order to steer flexible bevel-tipped needles. However, current systems depend on the information of maximum needle curvature, which is estimated by performing prior insertions. This work presents a new three-dimensional flexible needle steering system which integrates an optimal steering control, ultrasound-based needle tracking system, needle deflection model, online needle curvature estimation and offline curvature estimation based on biomechanics properties. The online and the offline curvature estimations are used to update the steering control in real time. The system is evaluated by experiments in gelatin phantoms and biological tissues (chicken breast tissues). The average targeting error in gelatin phantoms is 0.42 ± 0.17 mm, and in biological tissues is 1.63 ± 0.29 mm. The system is able to accurately steer a flexible needle in multi-layer phantoms and biological tissues without performing prior insertions to estimate the maximum needle curvature. PMID:25465619

  18. 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

  19. A Prototype Body-Mounted MRI-Compatible Robot for Needle Guidance in Shoulder Arthrography.

    PubMed

    Monfaredi, R; Seifabadi, R; Iordachita, I; Sze, R; Safdar, N M; Sharma, K; Fricke, S; Krieger, A; Cleary, K

    2014-08-01

    A novel compact and lightweight patient-mounted MRI-compatible robot has been designed for MRI image-guided interventions. This robot is intended to enable MRI-guided needle placement as done in shoulder arthrography. The robot could make needle placement more accurate and simplify the current workflow by converting the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure (streamlined workflow all in MRI suite). The robot has 4 degrees of freedom (DOF), two for orientation of the needle and two for needle positioning. The mechanical design was based on several criteria including rigidity, MRI compatibility, compact design, sterilizability, and adjustability. The proposed workflow is discussed and initial MRI compatibility experiments are presented. The results show that artifacts in the region of interest are minimal and that MRI images of the shoulder were not adversely affected by placing the robot on a human volunteer. PMID:25473653

  20. A Prototype Body-Mounted MRI-Compatible Robot for Needle Guidance in Shoulder Arthrography

    PubMed Central

    Monfaredi, R.; Seifabadi, R.; Iordachita, I.; Sze, R.; Safdar, N. M.; Sharma, K.; Fricke, S.; Krieger, A.; Cleary, K.

    2014-01-01

    A novel compact and lightweight patient-mounted MRI-compatible robot has been designed for MRI image-guided interventions. This robot is intended to enable MRI-guided needle placement as done in shoulder arthrography. The robot could make needle placement more accurate and simplify the current workflow by converting the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure (streamlined workflow all in MRI suite). The robot has 4 degrees of freedom (DOF), two for orientation of the needle and two for needle positioning. The mechanical design was based on several criteria including rigidity, MRI compatibility, compact design, sterilizability, and adjustability. The proposed workflow is discussed and initial MRI compatibility experiments are presented. The results show that artifacts in the region of interest are minimal and that MRI images of the shoulder were not adversely affected by placing the robot on a human volunteer. PMID:25473653

  1. Calibration of a needle tracking device with fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    K. Mandal, Koushik; Parent, Francois; Martel, Sylvain; Kashyap, Raman; Kadoury, Samuel

    2015-03-01

    Accurate needle placement is essential in percutaneous procedures such as radiofrequency ablation (RFA) of liver tumors. Use of real-time navigation of an interventional needle can improve targeting accuracy and yield precise measurements of the needle tip inside the body. An emerging technology based on Fiber Bragg Grating (FBG) sensors has demonstrated the potential of estimating shapes at high frequencies (up to 20 kHz), fast enough for real-time applications. In this paper, we present a calibration procedure for this novel needle tracking technology using strain measurements obtained from fiber Bragg gratings (FBGs). Three glass fibers equipped with two FBGs each were incorporated into a 19G needle. The 3D needle shape is reconstructed based on a polynomial fitting of strain measurements obtained from the fibers. The real-time information provided by the needle tip position and shape allows tracking of the needle deflections during tissue insertion. An experimental setup was designed to yield a calibration that is insensitive to ambient temperature fluctuations and robust to slight external disturbances. We compare the shape of the 3D reconstructed needle to measurements obtained from camera images, as well as assess needle tip tracking accuracy on a ground-truth phantom. Initial results show that the tracking errors for the needle tip are under 1mm, while 3D shape deflections are minimal near the needle tip. The accuracy is appropriate for applications such as RFA of liver tumors.

  2. MRI-guided prostate focal laser ablation therapy using a mechatronic needle guidance system

    NASA Astrophysics Data System (ADS)

    Cepek, Jeremy; Lindner, Uri; Ghai, Sangeet; Davidson, Sean R. H.; Trachtenberg, John; Fenster, Aaron

    2014-03-01

    Focal therapy of localized prostate cancer is receiving increased attention due to its potential for providing effective cancer control in select patients with minimal treatment-related side effects. Magnetic resonance imaging (MRI)-guided focal laser ablation (FLA) therapy is an attractive modality for such an approach. In FLA therapy, accurate placement of laser fibers is critical to ensuring that the full target volume is ablated. In practice, error in needle placement is invariably present due to pre- to intra-procedure image registration error, needle deflection, prostate motion, and variability in interventionalist skill. In addition, some of these sources of error are difficult to control, since the available workspace and patient positions are restricted within a clinical MRI bore. In an attempt to take full advantage of the utility of intraprocedure MRI, while minimizing error in needle placement, we developed an MRI-compatible mechatronic system for guiding needles to the prostate for FLA therapy. The system has been used to place interstitial catheters for MRI-guided FLA therapy in eight subjects in an ongoing Phase I/II clinical trial. Data from these cases has provided quantification of the level of uncertainty in needle placement error. To relate needle placement error to clinical outcome, we developed a model for predicting the probability of achieving complete focal target ablation for a family of parameterized treatment plans. Results from this work have enabled the specification of evidence-based selection criteria for the maximum target size that can be confidently ablated using this technique, and quantify the benefit that may be gained with improvements in needle placement accuracy.

  3. Full automatic fiducial marker detection on coil arrays for accurate instrumentation placement during MRI guided breast interventions

    NASA Astrophysics Data System (ADS)

    Filippatos, Konstantinos; Boehler, Tobias; Geisler, Benjamin; Zachmann, Harald; Twellmann, Thorsten

    2010-02-01

    With its high sensitivity, dynamic contrast-enhanced MR imaging (DCE-MRI) of the breast is today one of the first-line tools for early detection and diagnosis of breast cancer, particularly in the dense breast of young women. However, many relevant findings are very small or occult on targeted ultrasound images or mammography, so that MRI guided biopsy is the only option for a precise histological work-up [1]. State-of-the-art software tools for computer-aided diagnosis of breast cancer in DCE-MRI data offer also means for image-based planning of biopsy interventions. One step in the MRI guided biopsy workflow is the alignment of the patient position with the preoperative MR images. In these images, the location and orientation of the coil localization unit can be inferred from a number of fiducial markers, which for this purpose have to be manually or semi-automatically detected by the user. In this study, we propose a method for precise, full-automatic localization of fiducial markers, on which basis a virtual localization unit can be subsequently placed in the image volume for the purpose of determining the parameters for needle navigation. The method is based on adaptive thresholding for separating breast tissue from background followed by rigid registration of marker templates. In an evaluation of 25 clinical cases comprising 4 different commercial coil array models and 3 different MR imaging protocols, the method yielded a sensitivity of 0.96 at a false positive rate of 0.44 markers per case. The mean distance deviation between detected fiducial centers and ground truth information that was appointed from a radiologist was 0.94mm.

  4. Development and evaluation of a new image-based user interface for robot-assisted needle placements with the Robopsy system

    NASA Astrophysics Data System (ADS)

    Seitel, Alexander; Walsh, Conor J.; Hanumara, Nevan C.; Shepard, Jo-Anne; Slocum, Alexander H.; Meinzer, Hans-Peter; Gupta, Rajiv; Maier-Hein, Lena

    2009-02-01

    The main challenges of Computed Tomography (CT)-guided organ puncture are the mental registration of the medical imaging data with the patient anatomy, required when planning a trajectory, and the subsequent precise insertion of a needle along it. An interventional telerobotic system, such as Robopsy, enables precise needle insertion, however, in order to minimize procedure time and number of CT scans, this system should be driven by an interface that is directly integrated with the medical imaging data. In this study we have developed and evaluated such an interface that provides the user with a point-and-click functionality for specifying the desired trajectory, segmenting the needle and automatically calculating the insertion parameters (angles and depth). In order to highlight the advantages of such an interface, we compared robotic-assisted targeting using the old interface (non-image-based) where the path planning was performed on the CT console and transferred manually to the interface with the targeting procedure using the new interface (image-based). We found that the mean procedure time (n=5) was 22+/-5 min (non-image-based) and 19+/-1 min (image-based) with a mean number of CT scans of 6+/-1 (non-image-based) and 5+/-1 (image-based). Although the targeting experiments were performed in gelatin with homogenous properties our results indicate that an image-based interface can reduce procedure time as well as number of CT scans for percutaneous needle biopsies.

  5. Placement of tibial intraosseous infusion devices.

    PubMed

    Harcke, H Theodore; Crawley, Geoffrey; Mabry, Robert; Mazuchowski, Edward

    2011-07-01

    Post-mortem preautopsy multidetector computed tomography was used to assess the placement of tibial intraosseous infusion needles in 52 cases of battlefield trauma deaths for which medical intervention included the use of the technique. In 58 (95%) of 61 needles, the tip was positioned in medullary bone. All 3 (5%) unsuccessful placements were in the left leg, and the needle was not directed perpendicular to the medial tibial cortex as recommended. Considering the nature of military trauma and the environmental conditions under which care is rendered, military medical personnel appear to be highly successful in the placement of tibial intraosseous infusion needles. PMID:22128726

  6. Design of a Teleoperated Needle Steering System for MRI-guided Prostate Interventions

    PubMed Central

    Seifabadi, Reza; Iordachita, Iulian; Fichtinger, Gabor

    2013-01-01

    Accurate needle placement plays a key role in success of prostate biopsy and brachytherapy. During percutaneous interventions, the prostate gland rotates and deforms which may cause significant target displacement. In these cases straight needle trajectory is not sufficient for precise targeting. Although needle spinning and fast insertion may be helpful, they do not entirely resolve the issue. We propose robot-assisted bevel-tip needle steering under MRI guidance as a potential solution to compensate for the target displacement. MRI is chosen for its superior soft tissue contrast in prostate imaging. Due to the confined workspace of the MRI scanner and the requirement for the clinician to be present inside the MRI room during the procedure, we designed a MRI-compatible 2-DOF haptic device to command the needle steering slave robot which operates inside the scanner. The needle steering slave robot was designed to be integrated with a previously developed pneumatically actuated transperineal robot for MRI-guided prostate needle placement. We describe design challenges and present the conceptual design of the master and slave robots and the associated controller. PMID:24649480

  7. Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy.

    PubMed

    Liu, Shaoli; Xia, Zeyang; Liu, Jianhua; Xu, Jing; Ren, He; Lu, Tong; Yang, Xiangdong

    2016-01-01

    The "robotic-assisted liver tumor coagulation therapy" (RALTCT) system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1) multiple needles are needed to destroy the entire tumor, (2) the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3) the placement of multiple needles should avoid interference with each other, (4) an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles' operating environment, and (5) the multiple needle-insertion trajectories should be consistent with the needle-driven robot's movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle "collision-free reachable workspace" (CFRW), which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor therapy

  8. Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy

    PubMed Central

    Liu, Shaoli; Xia, Zeyang; Liu, Jianhua; Xu, Jing; Ren, He; Lu, Tong; Yang, Xiangdong

    2016-01-01

    The “robotic-assisted liver tumor coagulation therapy” (RALTCT) system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1) multiple needles are needed to destroy the entire tumor, (2) the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3) the placement of multiple needles should avoid interference with each other, (4) an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles’ operating environment, and (5) the multiple needle-insertion trajectories should be consistent with the needle-driven robot’s movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle “collision-free reachable workspace” (CFRW), which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor

  9. A new method to gently place biopsy needles or treatment electrodes into tissues with high target precision.

    PubMed

    Wiksell, Hans; Löfgren, Lars; Schässburger, Kai-Uwe; Leifland, Karin; Thorneman, Karin; Auer, Gert

    2016-05-01

    We present a new core needle biopsy and treatment electrode precision placement technique which, regardless of needle size, target lesion hardness and elasticity, makes it possible to precisely place an image guided device inside the abnormal tissue. Once inside the abnormal lesion, multiple tissue samples can be collected using a dedicated trocar and collecting system. Our unique "Fourier" driver substitutes the commonly used spring-loaded device or complements the jerky insertion technique used by experienced interventional physicians. It enables the physician to precisely and with extreme tactility maneuver even large diameter core needles or treatment-electrodes into the lesion using only a diminutive external force. This is achieved by applying supporting servo-controlled mechanical high-acceleration micro-pulses, proportional to the average vector directed by the physician. The Fourier-needle or Fourier-electrode stands completely non-moving when the system automatically goes into full idling. This means that the angle of attack successively and arbitrary can be aligned to hit the target, becoming successively symmetrically inserted into even small tumors to be treated as well as exactly hit any point outlined by real time ultrasound guiding. This kind of biopsy needle or treatment electrode placement results in a uniquely accurate and less traumatic procedure. Due to the risk of disseminating viable tumor cells the precision placement device can be combined with a computer controlled anti-seeding system, denaturizing tumor cells detached during penetration of the biopsy needle or treatment electrode. PMID:27132032

  10. 3T MR Guided in bore transperineal prostate biopsy: A Comparison of robotic and manual needle-guidance templates

    PubMed Central

    Tilak, Gaurie; Tuncali, Kemal; Song, Sang-Eun; Tokuda, Junichi; Olubiyi, Olutayo; Fennessy, Fiona; Fedorov, Andriy; Penzkofer, Tobias; Tempany, Clare; Hata, Nobuhiko

    2014-01-01

    Purpose To demonstrate the utility of a robotic needle-guidance template device as compared to a manual template for in-bore 3T transperineal MR-guided prostate biopsy. Materials and Methods This two-arm mixed retrospective-prospective study included 99 cases of targeted transperineal prostate biopsies. The biopsy needles were aimed at suspicious foci noted on multiparametric 3T MRI using manual template (historical control) as compared with a robotic template. The following data was obtained: the accuracy of average and closest needle placement to the focus, histologic yield, percentage of cancer volume in positive core samples, complication rate, and time to complete the procedure. Results 56 cases were performed using the manual template, and 43 cases were performed using the robotic template. The mean accuracy of the best needle placement attempt was higher in the robotic group (2.39 mm) than the manual group (3.71 mm, p<0.027). The mean core procedure time was shorter in the robotic (90.82min) than the manual group (100.63min, p<0.030). Percentage of cancer volume in positive core samples was higher in robotic group (p<0.001). Cancer yields and complication rates were not statistically different between the two sub-groups (p = 0.557 and p=0.172 respectively). Conclusion The robotic needle-guidance template helps accurate placement of biopsy needles in MRI-guided core biopsy of prostate cancer. PMID:25263213

  11. Characterization of optically actuated MRI-compatible active needles for medical interventions

    NASA Astrophysics Data System (ADS)

    Black, Richard J.; Ryu, Seokchang; Moslehi, Behzad; Costa, Joannes M.

    2014-03-01

    The development of a Magnetic Resonance Imaging (MRI) compatible optically-actuated active needle for guided percutaneous surgery and biopsy procedures is described. Electrically passive MRI-compatible actuation in the small diameter needle is provided by non-magnetic materials including a shape memory alloy (SMA) subject to precise fiber laser operation that can be from a remote (e.g., MRI control room) location. Characterization and optimization of the needle is facilitated using optical fiber Bragg grating (FBG) temperature sensors arrays. Active bending of the needle during insertion allows the needle to be accurately guided to even relatively small targets in an organ while avoiding obstacles and overcoming undesirable deviations away from the planned path due to unforeseen or unknowable tissue interactions. This feature makes the needle especially suitable for use in image-guided surgical procedures (ranging from MRI to CT and ultrasound) when accurate targeting is imperative for good treatment outcomes. Such interventions include reaching small tumors in biopsies, delineating freezing areas in, for example, cryosurgery and improving the accuracy of seed placement in brachytherapy. Particularly relevant are prostate procedures, which may be subject to pubic arch interference. Combining diagnostic imaging and actuation assisted biopsy into one treatment can obviate the need for a second exam for guided biopsy, shorten overall procedure times (thus increasing operating room efficiencies), address healthcare reimbursement constraints and, most importantly, improve patient comfort and clinical outcomes.

  12. Establishing an accurate diagnosis of a parotid lump: evaluation of the current biopsy methods - fine needle aspiration cytology, ultrasound-guided core biopsy, and intraoperative frozen section.

    PubMed

    Howlett, D C; Skelton, E; Moody, A B

    2015-09-01

    The optimum technique for histological confirmation of the nature of a parotid mass remains controversial. Fine needle aspiration cytology (FNAC), which has traditionally been used, is associated with high non-diagnostic and false negative rates, and ultrasound (US)-guided core biopsy and frozen section have been explored as alternatives. US-guided core biopsy is more invasive than FNAC, but is safe, well-tolerated, and associated with improved diagnostic performance. Although frozen section offers better specificity than FNAC, it has a number of important drawbacks and cannot be considered as a primary diagnostic tool. US-guided core biopsy should be considered as the initial diagnostic technique of choice, and in units where the accuracy of FNAC is good it can be used when FNAC is equivocal or non-diagnostic. PMID:25886878

  13. Validation system of MR image overlay and other needle insertion techniques.

    PubMed

    Fischer, Gregory S; Dyer, Eva; Csoma, Csaba; Deguet, Anton; Fichtinger, Gabor

    2007-01-01

    In order to develop accurate and effective augmented reality (AR) systems used in MR and CT guided needle placement procedures, a comparative validation environment is necessary. Clinical equipment is prohibitively expensive and often inadequate for precise measurement. Therefore, we have developed a laboratory validation system for measuring operator performance using different assistance techniques. Electromagnetically tracked needles are registered with the preoperative plan to measure placement accuracy and the insertion path. The validation system provides an independent measure of accuracy that can be applied to varying methods of assistance ranging from augmented reality guidance methods to tracked navigation systems and autonomous robots. In preliminary studies, this validation system is used to evaluate the performance of the image overlay, bi-plane laser guide, and traditional freehand techniques. PMID:17377250

  14. Navigated marker placement for motion compensation in radiotherapy

    NASA Astrophysics Data System (ADS)

    Winterstein, A.; März, K.; Franz, A. M.; Hafezi, M.; Fard, N.; Sterzing, F.; Mehrabi, A.; Maier-Hein, L.

    2015-03-01

    Radiotherapy is frequently used to treat unoperated or partially resected tumors. Tumor movement, e.g. caused by respiration, is a major challenge in this context. Markers can be implanted around the tumor prior to radiation therapy for accurate tracking of tumor movement. However, accurate placement of these markers while keeping a secure margin around the target and while taking into account critical structures is a difficult task. Computer-assisted needle insertion has been an active field of research in the past decades. However, the challenge of navigated marker placement for motion compensated radiotherapy has not yet been addressed. This work presents a system to support marker implantation for radiotherapy under consideration of safety margins and optimal marker configuration. It is designed to allow placement of markers both percutaneously and during an open liver surgery. To this end, we adapted the previously proposed EchoTrack system which integrates ultrasound (US) imaging and electromagnetic (EM) tracking in a single mobile modality. The potential of our new marker insertion concept was evaluated in a phantom study by inserting sets of three markers around dedicated targets (n=22) simultaneously spacing the markers evenly around the target as well as placing the markers in a defined distance to the target. In all cases the markers were successfully placed in a configuration fulfilling the predefined criteria. This includes a minimum distance of 18.9 ± 2.4 mm between marker and tumor as well as a divergence of 2.1 ± 1.5 mm from the planned marker positions. We conclude that our system has high potential to facilitate the placement of markers in suitable configurations for surgeons without extensive experience in needle punctions as high quality configurations were obtained even by medical non-experts.

  15. Keyword: Placement

    ERIC Educational Resources Information Center

    Cassuto, Leonard

    2012-01-01

    The practical goal of graduate education is placement of graduates. But what does "placement" mean? Academics use the word without thinking much about it. "Placement" is a great keyword for the graduate-school enterprise. For one thing, its meaning certainly gives a purpose to graduate education. Furthermore, the word is a portal into the way of…

  16. Design and fabrication of a low-frequency (1-3 MHz) ultrasound transducer for accurate placement of screw implants in the spine

    NASA Astrophysics Data System (ADS)

    Manbachi, Amir; Lee, Mike; Foster, F. Stuart; Ginsberg, Howard J.; Cobbold, Richard S. C.

    2014-03-01

    In 2012 approximately 800,000 spinal fusion surgeries were performed in the United States, requiring the insertion of screws into the pedicles. Their exact placement is critical and made complex due to limited visibility of the spine, continuous bleeding in the exposed regions, and variability in morphologies. The alarmingly high rate of screw misplacements (up to 20%) reported in the literature is of major concern since such misplacements can place the surrounding vital structures at risk. A potential guidance method for determining the best screw trajectory is by the use of real-time ultrasound imaging similar to that used for intravascular imaging. An endovascular transducer could be inserted into the pedicle to image the anatomy from within and identify bone boundaries. A major challenge of imaging within bone is high signal attenuation. The rapid increase of attenuation with frequency requires much lower frequencies (1-3 MHz) than those used in intravascular imaging. This study describes the custom design and fabrication of 2 MHz ultrasound probes (3.5 mm diameter/ 11 Fr) for pedicle screw guidance. Three transducer designs are explored to provide improved sensitivity and signal to noise ratio, compared to the previously tested transducer within the pedicle. Experimental measurements are compared with the results obtained using various simulation tools. The work reported in this paper represents the first stage in our ultimate goal of developing a 32- element phased array that is capable of generating a radial B-mode image.

  17. Diagnosis and fine needle aspiration of pancreatic pseudocysts: the role of endoscopic ultrasound.

    PubMed

    Breslin, Niall; Wallace, Michael B

    2002-10-01

    Pseudocysts are localized collections of pancreatic fluid surrounded by nonepithelialized granulation tissue that occur following an insult to the pancreas. High image resolution and the ability sample in real-time by fine needle aspiration permit accurate distinction between various cystic lesions in the pancreas by endoscopic ultrasound (EUS). Other cyst characteristics and background pancreatic changes detectable at EUS assist in the diagnostic process. The use of Doppler flow ultrasound allows diagnosis of important pseudocyst complications such as pseudoaneurysms and varices. Endoscopic approaches to the drainage of symptomatic lesions previously relied on the use of cross-sectional imaging studies such as computed tomography scanning in combination with stent placement using a duodenoscope in the presence of an endoscopically visible cyst bulge. EUS facilitates this process allowing accurate imaging of the lesion prior to stent placement via the echoendoscope and overcomes many of the drawbacks and pitfalls of other endoscopic techniques. PMID:12607787

  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. 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

  20. 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

  1. Human vs. robot operator error in a needle-based navigation system for percutaneous liver interventions

    NASA Astrophysics Data System (ADS)

    Maier-Hein, Lena; Walsh, Conor J.; Seitel, Alexander; Hanumara, Nevan C.; Shepard, Jo-Anne; Franz, A. M.; Pianka, F.; Müller, Sascha A.; Schmied, Bruno; Slocum, Alexander H.; Gupta, Rajiv; Meinzer, Hans-Peter

    2009-02-01

    Computed tomography (CT) guided percutaneous punctures of the liver for cancer diagnosis and therapy (e.g. tumor biopsy, radiofrequency ablation) are well-established procedures in clinical routine. One of the main challenges related to these interventions is the accurate placement of the needle within the lesion. Several navigation concepts have been introduced to compensate for organ shift and deformation in real-time, yet, the operator error remains an important factor influencing the overall accuracy of the developed systems. The aim of this study was to investigate whether the operator error and, thus, the overall insertion error of an existing navigation system could be further reduced by replacing the user with the medical robot Robopsy. For this purpose, we performed navigated needle insertions in a static abdominal phantom as well as in a respiratory liver motion simulator and compared the human operator error with the targeting error performed by the robot. According to the results, the Robopsy driven needle insertion system is able to more accurately align the needle and insert it along its axis compared to a human operator. Integration of the robot into the current navigation system could thus improve targeting accuracy in clinical use.

  2. Robotic system for MRI-guided prostate biopsy: feasibility of teleoperated needle insertion and ex vivo phantom study

    PubMed Central

    Seifabadi, Reza; Song, Sang-Eun; Krieger, Axel; Cho, Nathan Bongjoon; Tokuda, Junichi; Fichtinger, Gabor; Iordachita, Iulian

    2012-01-01

    Purpose Magnetic Resonance Imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. Methods We report the workspace optimization and phantom evaluation of a five Degree of Freedom (DOF) parallel pneumatically actuated modular robot for MRI-guided prostate biopsy. To shorten procedure time and consequently increase patient comfort and system accuracy, a prototype of a MRI-compatible master–slave needle driver module using piezo motors was also added to the base robot. Results Variable size workspace was achieved using appropriate link length, compared with the previous design. The 5-DOF targeting accuracy demonstrated an average error of 2.5mm (STD=1.37mm) in a realistic phantom inside a 3T magnet with a bevel-tip 18G needle. The average position tracking error of the master–slave needle driver was always below 0.1mm. Conclusion Phantom experiments showed sufficient accuracy for manual prostate biopsy. Also, the implementation of teleoperated needle insertion was feasible and accurate. These two together suggest the feasibility of accurate fully actuated needle placement into prostate while keeping the clinician supervision over the task. PMID:21698389

  3. Postanesthesia patients with large upper arm circumference: is use of an "extra-long" adult cuff or forearm cuff placement accurate?

    PubMed

    Watson, Sheri; Aguas, Marita; Bienapfl, Tracy; Colegrove, Pat; Foisy, Nancy; Jondahl, Bonnie; Yosses, Mary Beth; Yu, Larissa; Anastas, Zoe

    2011-06-01

    The purpose of this study was to determine if blood pressure (BP) measured in the forearm or with an extra-long BP cuff in the upper arm accurately reflects BP measured in the upper arm with an appropriately sized BP cuff in patients with large upper arm circumference. A method-comparison design was used with a convenience sample of 49 PACU patients. Noninvasive blood pressures were obtained in two different locations (forearm; upper arm) and in the upper arm with an extra-long adult and recommended large adult cuff sizes. Data were analyzed by calculating bias and precision for the BP cuff size and location and Student's t-tests, with P < .0125 considered significant. Significantly higher forearm systolic (P < .0001) and diastolic (P < .0002) BP measurements were found compared to BP obtained in the upper arm with the reference standard BP cuff. Significantly higher systolic (t(48df) = 5.38, P < .0001), but not diastolic (t(48df) = 4.11, P < .019), BP differences were found for BP measured with the extra-long cuff at the upper arm site compared to the upper arm, reference standard BP. Findings suggest that the clinical practice of using the forearm or an extra-long cuff in the upper arm for BP measurement in post anesthesia patients with large upper arm circumferences may result in inaccurate BP values. PMID:21641528

  4. 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

  5. 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.

  6. Target motion predictions for pre-operative planning during needle-based interventions.

    PubMed

    op den Buijs, Jorn; Abayazid, Momen; de Korte, Chris L; Misra, Sarthak

    2011-01-01

    During biopsies, breast tissue is subjected to displacement upon needle indentation, puncture, and penetration. Thus, accurate needle placement requires pre-operative predictions of the target motions. In this paper, we used ultrasound elastography measurements to non-invasively predict elastic properties of breast tissue phantoms. These properties were used in finite element (FE) models of indentation of breast soft tissue phantoms. To validate the model predictions of target motion, experimental measurements were carried out. Breast tissue phantoms with cubic and hemispherical geometries were manufactured and included materials with different elastic properties to represent skin, adipose tissue, and lesions. Ultrasound was used to track the displacement of the target (i.e., the simulated lesion) during indentation. The FE model predictions were compared with ultrasound measurements for cases with different boundary conditions and phantom geometry. Maximum errors between measured and predicted target motions were 12% and 3% for the fully supported and partially supported cubic phantoms at 6.0 mm indentation, respectively. Further, FE-based parameter sensitivity analysis indicated that increasing skin elastic modulus and reducing the target depth location increased the target motion. Our results indicate that with a priori knowledge about the geometry, boundary conditions, and linear elastic properties, indentation of breast tissue phantoms can be accurately predicted with FE models. FE models for pre-operative planning in combination with robotic needle insertions, could play a key role in improving lesion targeting for breast biopsies. PMID:22255554

  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. 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

  9. 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

  10. 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

  11. 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.

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

    NASA Astrophysics Data System (ADS)

    Pekárek, Stanislav

    2014-12-01

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

  13. Augmented reality needle guidance improves facet joint injection training

    NASA Astrophysics Data System (ADS)

    Ungi, Tamas; Yeo, Caitlin T.; U-Thainual, Paweena; McGraw, Robert C.; Fichtinger, Gabor

    2011-03-01

    PURPOSE: The purpose of this study was to determine if medical trainees would benefit from augmented reality image overlay and laser guidance in learning how to set the correct orientation of a needle for percutaneous facet joint injection. METHODS: A total of 28 medical students were randomized into two groups: (1) The Overlay group received a training session of four insertions with image and laser guidance followed by two insertions with laser overlay only; (2) The Control group was trained by carrying out six freehand insertions. After the training session, needle trajectories of two facet joint injections without any guidance were recorded by an electromagnetic tracker and were analyzed. Number of successful needle placements, distance covered by needle tip inside the phantom and procedural time were measured to evaluate performance. RESULTS: Number of successful placements was significantly higher in the Overlay group compared to the Control group (85.7% vs. 57.1%, p = 0.038). Procedure time and distance covered inside phantom have both been found to be less in the Overlay group, although not significantly. CONCLUSION: Training with augmented reality image overlay and laser guidance improves the accuracy of facet joint injections in medical students learning image-guided facet joint needle placement.

  14. Surface-blended texturing of medical needles for friction reduction using a picosecond laser

    NASA Astrophysics Data System (ADS)

    Wang, Xingsheng; Han, Peidong; Kang, Min; Ehmann, Kornel

    2016-04-01

    The success of percutaneous procedures depends on the accuracy of the medical needle insertion. Reducing the insertion force and using better needle visualization during needle insertion can reduce needle placement errors. Surface texturing is frequently used to create micro-features on medical needle's tip portion to improve the visibility in ultrasound-guided percutaneous procedures. However, these micro-features usually increase the friction between the needle and tissue because of stress concentrations. This paper explores a method for creating micro-features with blended edges on echogenic needles and studies the friction behavior between textured echogenic needles and phantom tissue to identify blended texture patterns that would minimize the friction during needle insertion. Laser surface texturing was used to create regular micro-circumferential channels and micro-corner-cube-like dimples along the needle's axial direction. Variations of the overlap in the feed direction were used to blend the edges of micro-channels and micro-dimples with different fillet radii. Both needles with regular and blended surface textures were experimentally investigated through needle extraction experiments from phantom tissue. It was found that the blended textured needles with large fillet radii exhibit a much better friction behavior.

  15. 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.

  16. 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.

  17. 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

  18. [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

  19. Closed-loop asymmetric-tip needle steering under continuous intraoperative MRI guidance.

    PubMed

    Patel, Niravkumar A; van Katwijk, Tim; Li, Gang; Moreira, Pedro; Shang, Weijian; Misra, Sarthak; Fischer, Gregory S

    2015-08-01

    Magnetic resonance imaging (MRI) provides excellent image contrast for various types of tissues, making it a suitable choice over other imaging modalities for various image-guided needle interventions. Furthermore, robot-assistance is maturing for surgical procedures such as percutaneous prostate and brain interventions. Although MRI-guided, robot-assisted needle interventions are approaching clinical usage, they are still typically open-loop in nature due to the lack of continuous intraoperative needle tracking. Closed-loop needle-based procedures can improve the accuracy of needle tip placement by correcting the needle trajectory during insertion. This paper proposes a system for robot-assisted, flexible asymmetric-tipped needle interventions under continuous intraoperative MRI guidance. A flexible needle's insertion depth and rotation angle are manipulated by an MRI-compatible robot in the bore of the MRI scanner during continuous multi-planar image acquisition to reach a desired target location. Experiments are performed on gelatin phantoms to assess the accuracy of needle placement into the target location. The system was able to successfully utilize live MR imaging to guide the path of the needle, and results show an average total targeting error of 2.5±0.47mm, with an average in-plane error of 2.09±0.33mm. PMID:26737384

  20. The Path-of-Probability Algorithm for Steering and Feedback Control of Flexible Needles

    PubMed Central

    Park, Wooram; Wang, Yunfeng; Chirikjian, Gregory S.

    2010-01-01

    In this paper we develop a new framework for path planning of flexible needles with bevel tips. Based on a stochastic model of needle steering, the probability density function for the needle tip pose is approximated as a Gaussian. The means and covariances are estimated using an error propagation algorithm which has second order accuracy. Then we adapt the path-of-probability (POP) algorithm to path planning of flexible needles with bevel tips. We demonstrate how our planning algorithm can be used for feedback control of flexible needles. We also derive a closed-form solution for the port placement problem for finding good insertion locations for flexible needles in the case when there are no obstacles. Furthermore, we propose a new method using reference splines with the POP algorithm to solve the path planning problem for flexible needles in more general cases that include obstacles. PMID:21151708

  1. Stereotaxic implantation of dispersed cell suspensions into brain. A systematic appraisal of cell placement and survival

    SciTech Connect

    Plunkett, R.J.; Weber, R.J.; Oldfield, E.H.

    1988-08-01

    The application of several recent advances in cell biology, brain implantation, and cell-mediated tumor immunotherapy requires successful and reproducible placement of viable cell suspensions into brain. Stereotaxic implantation is being used to inject cytotoxic lymphocytes into gliomas and to replace dopaminergic cells in parkinsonian models. Systematic assessment of the factors that influence success in implantation of cell suspensions into solid tissues is needed. A model was developed for investigation of stereotaxic implantation using radiolabeled rat lymphokine-activated killer (LAK) cells. Anesthetized rats received microliter injections of cell suspension into the right caudate nucleus. The injection volume, cell concentration, infusion rate, and needle size were varied systematically. The animals were sacrificed 1 hour after injection; the brain was removed and sectioned, and the radioactivity was counted. Three aliquots of the suspension were injected into counting tubes for control analysis. Recovery of radioactivity was expressed as the percent of mean counts per minute (cpm) in the right frontal lobe/mean cpm in the three control tubes. To assess the viability of implanted cells, the right frontal region was mechanically dissociated in media and centrifuged, and the pellet and supernatant were counted. By using small needles and slow infusion of volumes of 10 microliters or less, 85% to 90% of the radioactivity was recovered in the caudate nucleus. At least half of the implanted cells were viable. Consistent, accurate implantation of dispersed cells into brain over a range of volumes, cell concentrations, infusion rates, and needle sizes was achieved.

  2. Target Tracking, Approach, and Camera Handoff for Automated Instrument Placement

    NASA Technical Reports Server (NTRS)

    Bajracharya, Max; Diaz-Calderon, Antonio; Robinson, Matthew; Powell, Mark

    2005-01-01

    This paper describes the target designation, tracking, approach, and camera handoff technologies required to achieve accurate, single-command autonomous instrument placement for a planetary rover. It focuses on robust tracking integrated with obstacle avoidance during the approach phase, and image-based camera handoff to allow vision-based instrument placement. It also provides initial results from a complete system combining these technologies with rover base placement to maximize arm manipulability and image-based instrument placement.

  3. 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.

  4. 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

  5. [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

  6. Prostate Brachytherapy With Oblique Needles to Treat Large Glands and Overcome Pubic Arch Interference

    SciTech Connect

    Ryu, Bon; Bax, Jeff; Edirisinge, Chandima; Lewis, Craig; Chen, Jeff; D'Souza, David; Fenster, Aaron; Wong, Eugene

    2012-08-01

    Purpose: First, to show that low-dose-rate prostate brachytherapy plans using oblique needle trajectories are more successful than parallel trajectories for large prostates with pubic arch interference (PAI); second, to test the accuracy of delivering an oblique plan by using a three-dimensional (3D) transrectal ultrasonography (TRUS)-guided mechatronic system. Methods and Materials: Prostates were contoured for 5 subjects' 3D TRUS images showing a maximum PAI of {<=}1 cm and a prostate volume of <50 cc. Two planning studies were done. First, prostate contours were artificially enlarged to 45 to 80 cc in 5- to 10-cc increments for a single subject. Second, all subject prostate contours were enlarged to 60 cc. For each study, three types of plans were manually created for comparison: a parallel needle template (PT) plan, a parallel needle no-template (PNT) plan, and an oblique needle no-template (OBL) plan. Needle positions and angles were not discretized for nontemplate plans. European Society for Therapeutic Radiology and Oncology dose-volume histogram guidelines, iodine-125 (145-Gy prescription, 0.43 U), and needle angles of <15 Degree-Sign were used. An OBL plan was delivered to a pubic arch containing a 60-cc prostate phantom that mimicked the anatomy of the subject with the greatest PAI (23% by volume). Results: In the increasing-prostate volume study, OBL plans were successful for prostates of {<=}80 cc, and PT plans were successful for prostates of <65 cc. In paired, one-sided t tests for the 60-cc volume study, OBL plans showed dosimetric improvements for all organs compared to both of the parallel type plans (p < 0.05); PNT plans showed a benefit only in planning target volumes receiving more than 100 Gy compared to PT plans. A computed tomography scan of the phantom showed submillimeter seed placement accuracy in all directions. Conclusion: OBL plans were significantly better than parallel plans, and an OBL plan was accurately delivered to a 60-cc

  7. 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

  8. Complications of needle thoracostomy: A comprehensive clinical review

    PubMed Central

    Wernick, Brian; Hon, Heidi H; Mubang, Ronnie N; Cipriano, Anthony; Hughes, Ronson; Rankin, Demicha D; Evans, David C; Burfeind, William R; Hoey, Brian A; Cipolla, James; Galwankar, Sagar C; Papadimos, Thomas J; Stawicki, Stanislaw P; Firstenberg, Michael S

    2015-01-01

    Needle thoracostomy (NT) is a valuable adjunct in the management of tension pneumothorax (tPTX), a life-threatening condition encountered mainly in trauma and critical care environments. Most commonly, needle thoracostomies are used in the prehospital setting and during acute trauma resuscitation to temporize the affected individuals prior to the placement of definitive tube thoracostomy (TT). Because it is both an invasive and emergent maneuver, NT can be associated with a number of potential complications, some of which may be life-threatening. Due to relatively common use of this procedure, it is important that healthcare providers are familiar, and ready to deal with, potential complications of NT. PMID:26557486

  9. 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 ...

  10. 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

  11. A Placement Advisory Test

    ERIC Educational Resources Information Center

    Hughes, Chris

    2010-01-01

    The primary method of placement at Portland CC (PCC) is the Compass Placement test. For the most part, students are placed correctly, but there are cases when students feel that they have been placed too low. In such cases we use our newly created Placement Advisory Test (PAT) to help us place them appropriately. (Contains 2 figures.)

  12. Job Placement Handbook.

    ERIC Educational Resources Information Center

    Los Angeles Unified School District, CA. Div. of Career and Continuing Education.

    Designed to serve as a guide for job placement personnel, this handbook is written from the point of view of a school or job preparation facility, based on methodology applicable to the placement function in any setting. Factors identified as critical to a successful placement operation are utilization of a systems approach, establishment of…

  13. 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

  14. 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

  15. Automatic Brachytherapy Seed Placement Under MRI Guidance

    PubMed Central

    Patriciu, Alexandru; Petrisor, Doru; Muntener, Michael; Mazilu, Dumitru; Schär, Michael; Stoianovici, Dan

    2011-01-01

    The paper presents a robotic method of performing low dose rate prostate brachytherapy under magnetic resonance imaging (MRI) guidance. The design and operation of a fully automated MR compatible seed injector is presented. This is used with the MrBot robot for transperineal percutaneous prostate access. A new image-registration marker and algorithms are also presented. The system is integrated and tested with a 3T MRI scanner. Tests compare three different registration methods, assess the precision of performing automated seed deployment, and use the seeds to assess the accuracy of needle targeting under image guidance. Under the ideal conditions of the in vitro experiments, results show outstanding image-guided needle and seed placement accuracy. PMID:17694871

  16. Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants.

    PubMed

    Thompson, S A; Fung, A Y C; Zaider, M

    2002-08-21

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with 1-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. PMID:12222865

  17. NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    NASA Astrophysics Data System (ADS)

    Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

    2002-08-01

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

  18. Benefits of multislice CT-fluoroscopy needle guidance in Percutaneous Laser Disc Decompression (PLDD)

    NASA Astrophysics Data System (ADS)

    Brat, Hugues G.; Bouziane, Tarik; Lambert, Jean; Divano, Luisa

    2004-09-01

    Multislice fluoro-CT allows 3 dimensional millimetric precision in needle guidance and placement. The main benefit of this technique is a volumetric approach with precise management of the patient's Z-axis. This allows performing fast procedures, low x-ray exposure of the patient, central needle positioning inside the disc, absence of radicular lesion, absence of technical failure of the procedure. It can be considered therefore as the safest technique to perform fast and efficient Percutaneous Laser Disc Decompression (PLDD).

  19. Needle Federated Search Engine

    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

  20. 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.

  1. 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

  2. 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 ...

  3. 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 ...

  4. 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

  5. Cultural Bias in Special Education Assessment and Placement.

    ERIC Educational Resources Information Center

    Rose, Ernest; Huefner, Dixie S.

    Advocates for minority students charge that special education placement of racially or culturally different students is unfair because the tests, standardized on white, middle-class children, do not accurately reflect the learning rate or potential achievement level of others. For this reason, reliance on IQ tests for placement of minority…

  6. Understanding the Heritage Language Student: Proficiency and Placement

    ERIC Educational Resources Information Center

    Thompson, Gregory L.

    2015-01-01

    Given the ever-growing number of Spanish heritage learners in both universities and colleges, the need has continued to grow for the development of placement exams that accurately measure language ability, are simple to evaluate, and are easy to administer to large numbers of students. This article analyzes the implementation of a placement exam…

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

    SciTech Connect

    McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J.

    2012-04-15

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

  8. Getting to the point: indications for fine-needle aspiration of internal organs and bone.

    PubMed

    Wypij, Jackie M

    2011-05-01

    The technique of fine-needle biopsy (fine-needle aspiration or fine-needle fenestration) for cytologic evaluation can be extended to many sites beyond the traditional lymph node and skin. Intra-abdominal, intrathoracic, and bone lesions can be easily and rapidly evaluated cytologically. Percutaneous fine-needle aspiration and fine-needle fenestration are useful, accurate, and inexpensive techniques with a rapid turnaround time, and outpatient applicability. For most pets, these minimally invasive techniques do not require anesthesia or analgesia. Although risks are inherent with any invasive procedure, complications are uncommon even with visceral and intrathoracic fine-needle biopsy. Attention to appropriate technique and close patient monitoring minimize the morbidity and improve the diagnostic utility. The low cost, low risk, minimal invasiveness, and high diagnostic yield make fine-needle biopsy particularly attractive to clients. In combination with ultrasound guidance and newer staining techniques, these diagnostic procedures are invaluable to the veterinary clinician. PMID:21596347

  9. Math Sense: Placement Test.

    ERIC Educational Resources Information Center

    2003

    Math Sense consists of five books that develop from basic to more advanced math skills. This document contains a placement test used with Math Sense to help students and their teachers decide into which Math Sense book to begin working. The placement test is divided into six parts, each consisting of 10 to 22 problems, and is based on exit skill…

  10. Computers and Placement.

    ERIC Educational Resources Information Center

    Devlin, Thomas; And Others

    1984-01-01

    Describes computerized placement programs at three colleges. Cornell University developed a microcomputer program while Virginia Polytechnic Institute and State University used the university's mainframe system. College of Lake County found that computerized job placement meant a stronger link with the business community. (JAC)

  11. Job Placement Primer.

    ERIC Educational Resources Information Center

    Wampler, Elizabeth C.

    The publication presents guidelines to assist secondary schools in developing and implementing a job placement service within an existing guidance program. The need for and the goals of a school placement program are given. Areas to be considered in developing a program according to one of three organizational patterns (decentralized, centralized,…

  12. Transbronchial needle aspiration. An underused diagnostic technique.

    PubMed

    Dasgupta, A; Mehta, A C

    1999-03-01

    (by watching video) Review pathology slides Acquisition of skills with cytology needles should precede the use of the histology needle. Increasing education and experience can also increase diagnostic yields. Transbronchial needle aspiration has been proven to be accurate in staging lung cancers, identifying inoperable carcinomas, and diagnosing a variety of lung diseases. Few complications have been encountered and the technique is less invasive and less costly than surgical procedures. Drawing on evidence from published literature, we suggest the following guidelines for TBNA: All patients presenting with mediastinal or hilar adenopathy or both, should have 22-ga and/or 19-ga TBNA as the initial procedure. These procedures would help diagnose malignant and nonmalignant diseases, and stage lung cancers. All patients with evidence of submucosal and peribronchial disease should have 22-ga needle cytology sampling. In patients with visible endobronchial disease, 22-ga TBNA should be optional. In the presence of a necrotic or a hemorrhagic tumor, or in a patient with a bleeding diathesis, TBNA would be helpful. In all patients with Type III and IV peripheral nodules, TBNA should be the initial diagnostic procedure. There remains no doubt about the diagnostic usefulness of TBNA. Guidelines must be developed to ensure that pulmonary fellows are adequately trained in this procedure. Regional workshops with hands-on experience targeted to practicing pulmonologists organized by the ACCP would help popularize the procedure. Initial low yields should not discourage pulmonologists from using the procedure. Collaboration between thoracic surgeons, oncologists, and pulmonary physicians is essential to set up TBNA programs within institutions. With time, as more and more pulmonologists attain expertise in TBNA, the full potential of this nonsurgical, cost-effective, and safe procedure will be realized. PMID:10205716

  13. Development of 3D ultrasound needle guidance for high-dose-rate interstitial brachytherapy of gynaecological cancers

    NASA Astrophysics Data System (ADS)

    Rodgers, J.; Tessier, D.; D'Souza, D.; Leung, E.; Hajdok, G.; Fenster, A.

    2016-04-01

    High-dose-rate (HDR) interstitial brachytherapy is often included in standard-of-care for gynaecological cancers. Needles are currently inserted through a perineal template without any standard real-time imaging modality to assist needle guidance, causing physicians to rely on pre-operative imaging, clinical examination, and experience. While two-dimensional (2D) ultrasound (US) is sometimes used for real-time guidance, visualization of needle placement and depth is difficult and subject to variability and inaccuracy in 2D images. The close proximity to critical organs, in particular the rectum and bladder, can lead to serious complications. We have developed a three-dimensional (3D) transrectal US system and are investigating its use for intra-operative visualization of needle positions used in HDR gynaecological brachytherapy. As a proof-of-concept, four patients were imaged with post-insertion 3D US and x-ray CT. Using software developed in our laboratory, manual rigid registration of the two modalities was performed based on the perineal template's vaginal cylinder. The needle tip and a second point along the needle path were identified for each needle visible in US. The difference between modalities in the needle trajectory and needle tip position was calculated for each identified needle. For the 60 needles placed, the mean trajectory difference was 3.23 +/- 1.65° across the 53 visible needle paths and the mean difference in needle tip position was 3.89 +/- 1.92 mm across the 48 visible needles tips. Based on the preliminary results, 3D transrectal US shows potential for the development of a 3D US-based needle guidance system for interstitial gynaecological brachytherapy.

  14. Using Multiple Measures to Make Math Placement Decisions: Implications for Access and Success in Community Colleges

    ERIC Educational Resources Information Center

    Ngo, Federick; Kwon, William W.

    2015-01-01

    Community college students are often placed in developmental math courses based on the results of a single placement test. However, concerns about accurate placement have recently led states and colleges across the country to consider using other measures to inform placement decisions. While the relationships between college outcomes and such…

  15. Controlling a Robotically Steered Needle in the Presence of 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 orientation of the bevel tip as the needle is inserted into tissue. Here, we demonstrate the significant effect of friction between the long, flexible needle shaft and the tissue, which can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial frictional forces to the needle shaft, resulting in a lag of over 45° for a 10 cm insertion depth in some phantoms; clinical studies have reported torques large enough to could 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 a model for the rotational dynamics of a needle being continuously inserted into tissue and show how a PD controller is sufficient to compensate for the rotational dynamics. PMID:21461175

  16. 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

  17. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern.

    PubMed

    Borot de Battisti, M; Maenhout, M; Denis de Senneville, B; Hautvast, G; Binnekamp, D; Lagendijk, J J W; van Vulpen, M; Moerland, M A

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm(3)to 23.3 cm(3)) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions. PMID:26378657

  18. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    NASA Astrophysics Data System (ADS)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  19. Polyacrylamide phantom for self-actuating needle-tissue interaction studies.

    PubMed

    Datla, Naresh V; Konh, Bardia; Koo, Joe J Y; Choi, Daniel J W; Yu, Yan; Dicker, Adam P; Podder, Tarun K; Darvish, Kurosh; Hutapea, Parsaoran

    2014-01-01

    This study presents a polyacrylamide gel as a phantom material for needle insertion studies specifically developed for self-actuating needles to enhance the precise placement of needles in prostate. Bending of these self-actuating needles within tissue is achieved by Nitinol actuators attached to the needle body; however these actuators usually involve heating that can thermally damage the tissue surrounding the needles. Therefore, to develop and access feasibility of these needles, a polyacrylamide gel has been developed that mimics the thermal damage and mechanical properties of prostate tissue. Mechanical properties of the polyacrylamide gel was controlled by varying the concentrations of acrylamide monomer and N,N-methylene-bisacrylamide (BIS) cross-linker, and thermal sensitivity was achieved by adding bovine serum albumin (BSA) protein. Two polyacrylamide gels with different concentrations were developed to mimic the elastic modulus of the tissue. The two phantoms showed different rupture toughness and different deflection of bevel-tip needle. To study the thermal damage, a Nitinol wire was embedded in the phantom and resistively heated. The measured opaque zone (0.40mm) formed around the wire was close to the estimated damage zone (0.43mm) determined using the cumulative equivalent minutes at 43°C. PMID:23932314

  20. 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.

  1. ESL Placement and Schools

    PubMed Central

    Callahan, Rebecca; Wilkinson, Lindsey; Muller, Chandra; Frisco, Michelle

    2010-01-01

    In this study, the authors explore English as a Second Language (ESL) placement as a measure of how schools label and process immigrant students. Using propensity score matching and data from the Adolescent Health and Academic Achievement Study and the National Longitudinal Study of Adolescent Health, the authors estimate the effect of ESL placement on immigrant achievement. In schools with more immigrant students, the authors find that ESL placement results in higher levels of academic performance; in schools with few immigrant students, the effect reverses. This is not to suggest a one-size-fits-all policy; many immigrant students, regardless of school composition, generational status, or ESL placement, struggle to achieve at levels sufficient for acceptance to a 4-year university. This study offers several factors to be taken into consideration as schools develop policies and practices to provide immigrant students opportunities to learn. PMID:20617111

  2. The Placement Annual Report

    ERIC Educational Resources Information Center

    Segal, Stanley; And Others

    1970-01-01

    Two part presentation consisting, first, of study of reports indicating lack of imagination on part of placement directors, and second, of a nonstereotyped approach which puts emphasis on operating principles rather than on statistical data. (Author/CJ)

  3. Lumbar Catheter Placement Using Paramedian Approach Under Fluoroscopic Guidance

    PubMed Central

    Qureshi, Adnan I.; Khan, Asif A.; Malik, Ahmed A.; Afzal, Mohammad Rauf; Herial, Nabeel A.; Qureshi, Mushtaq H.; Suri, M. Fareed K.

    2016-01-01

    Background Lumbar catheter placement under fluoroscopic guidance may reduce the rate of technical failures and associated complications seen with insertion guided by manually palpable landmarks. Methods We reviewed our experience with 43 attempted lumbar catheter placements using paramedian approach under fluoroscopic guidance and ascertained rates of technical success, and clinical events. Results Among the 43 patients, 18, 1, and 1 patients were on aspirin (with dipyrimadole in 2), clopidogrel, and combination of both, respectively. Lumbar catheter placement was successful in 42 of 43 attempted placements. Floroscopic guidance was critical in three patients; one patient had severe cerebrospinal fluid (CSF) depletion (empty thecal sac phenomenon) following pituitary surgery leading to no cerebrospinal fluid return despite correct placement confirmation under fluoroscopy. Two patients had spinal needle placement at the junction between epidural and cerebrospinal fluid spaces (junctional position) leading to cerebrospinal fluid return but inability to introduce the lumbar catheter. After confirmation of position by the injection of contrast or radiographic landmarks the needle was advanced by indenting the subcutaneous tissue or reinserting at a spinal level above the first insertion. The lumbar catheter remained in position over a mean period (±standard deviation) of 4.1(±2.3) days. Improvement in hydrocephalus was seen in two patients with intracranial mass lesions. One patient developed cerebrospinal fluid leakage through the insertion track following removal of catheter and required skin suturing at the site of insertion. Conclusions We observed a high technical success rate with low rate of complications even in patients with intracranial mass lesions, those on ongoing antiplatelet medications or in whom insertion would not be possible guided by manually palpable landmarks. PMID:26958156

  4. An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy.

    PubMed

    Hong, J; Dohi, T; Hashizume, M; Konishi, K; Hata, N

    2004-02-01

    A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target. PMID:15012012

  5. Fine-needle aspiration biopsy and other biopsies in suspected intraocular malignant disease: a review.

    PubMed

    Eide, Nils; Walaas, Lisa

    2009-09-01

    Ocular oncologists require a strong indication for intraocular biopsy before the procedure can be performed because it carries a risk for serious eye complications and the dissemination of malignant cells. The purpose of this review is to evaluate the extent to which this restricted practice is supported by evidence from previous reports and to outline our main indications and contraindications. The different intraocular biopsy techniques in the anterior and posterior segment are discussed with a focus on our preferred method, fine-needle aspiration biopsy (FNAB). In the literature, complications are typically under-reported, which reduces the possibilities of evaluating the risks correctly and of making fair comparisons with other biopsy methods. In FNAB, the exact placement of the needle is critical, as is an accurate assessment of the size of the lesion. Fine-needle aspiration biopsy is usually not a reliable diagnostic tool in lesions < 2 mm in thickness. It is very advantageous to have a cytopathologist present in the operating theatre or close by. This ensures adequate sampling and encourages repeated biopsy attempts if necessary. This approach reduces false negative results to < 3%. Adjunct immunocytochemistry is documented to increase specificity and is essential for diagnosis and management in about 10% of cases. In some rare pathological processes the diagnosis depends ultimately on the identification of specific cell markers. An accurate diagnosis may have a decisive influence on prognosis. The cytogenetic prognostications made possible after FNAB are reliable. Biopsy by FNA has a low complication rate. The calculated risk for retinal detachment is < 4%. Intraocular haemorrhage is frequently observed, but clears spontaneously in nearly all cases. Only a single case of epibulbar seeding of malignant cells at the scleral pars plana puncture site of transvitreal FNAB has been documented. Endophthalmitis has been reported and adequate standard preoperative

  6. Stereotactic catheter placement for Ommaya reservoirs.

    PubMed

    Kennedy, Benjamin C; Brown, Lauren T; Komotar, Ricardo J; McKhann, Guy M

    2016-05-01

    Ommaya reservoirs are an important surgical therapy for the chronic intrathecal administration of chemotherapy for patients with leptomeningeal carcinomatosis. Surgical accuracy is paramount in these patients with typically normal sized ventricles, and may be improved with stereotactic guidance. This paper aimed to review a large series of stereotactic Ommaya catheter placements, examining accuracy and complications. We conducted a retrospective review of 109 consecutive adult patients who underwent stereotactic Ommaya catheter placement for leptomeningeal carcinomatosis or central nervous system lymphoma at Columbia University Medical Center, USA, from 1998-2013. The rate of accurate placement in the ventricular system was 99%, with the only poor catheter position due to post-placement migration. The rate of peri-operative complications was 6.4%. Hemorrhagic complications occurred in patients with thrombocytopenia or therapeutic anti-coagulation pre-operatively or during the post-operative period. Use of stereotaxy for catheter placement of Ommaya reservoirs is safe and effective, and should be considered when placing a catheter into non-hydrocephalic ventricles. PMID:26778516

  7. In-vivo measurement of surgical needle intervention parameters: a pilot study.

    PubMed

    Podder, T K; Sherman, J; Fuller, D; Messing, E M; Rubens, D J; Strang, J G; Brasacchio, R A; Yu, Y

    2006-01-01

    Percutaneous intervention is essential in numerous medical diagnostic and therapeutic procedures. In these procedures, accurate insertion of the surgical needle is very important. But precise interstitial intervention is quite challenging. Robot-assisted needle intervention can significantly improve accuracy and consistency of various medical procedures. To design and control any robotic system, the design and control engineers must know the forces that will be encountered by the system and the motion trajectories that the needling mechanism will have to follow. Several researchers have reported needle insertion forces encountered while steering through soft tissue and soft material phantoms, but hardly any in-vivo force measurement data is available in the literature. In this paper, we present needle insertion forces and motion trajectories measured during actual brachytherapy needle insertion while implanting radioactive seeds in the prostate glands of twenty five patients. PMID:17946194

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

    PubMed

    Peterson, I M; Brink, W J

    1990-09-01

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

  9. Simulation and experimental studies of the SMA-activated needle behavior inside the tissue

    NASA Astrophysics Data System (ADS)

    Konh, Bardia; Honarvar, Mohammad; Hutapea, Parsaoran

    2015-04-01

    Recently, the concept of developing an active steerable needle has gathered a lot of attention as they could potentially result in an improved outcome in various medical percutaneous procedures. Compared to the conventional straight bevel tip needles, active needles can be bent by means of the attached actuation component in order to reach the target locations more accurately. In this study, the movement of the passive needle inside the tissue was investigated using numerical and experimental approaches. A finite element simulation of needle insertion was developed using LSDYNA software to study the maneuverability of the passive needle. The Arbitrary-Eulerian-Lagrangian (ALE) formulation was used to model the interactions between the solid elements of the needle and the fluid elements of the tissue. Also the passive needle insertion tests were performed inside a tissue mimicking phantom. This model was validated for the 150mm of insertion which is similar to the depth in our needle insertion experiments. The model is intended to be based as a framework for modeling the active needle insertion in future.

  10. 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

  11. How to increase the yield of transbronchial needle aspiration (TBNA)?

    PubMed Central

    Chen, Cheng

    2015-01-01

    Transbronchial needle aspiration (TBNA) is a relatively sensitive, accurate, and safe technique in the diagnosis and staging of lung cancer. There are many factors influencing the yield of TBNA, such as location and the size of the mediastinal lymphadenopathy (MLN), types of the needle used and the experience of the bronchoscopist. Furthermore, knowledge of anatomy, guidance, availability of rapid on-site evaluation (ROSE) and the number of aspirates, preparation of specimen and interpretations of the cytology and histology of specimens all play important roles. Especially, whether an endobronchial ultrasound (EBUS) is required for TBNA in the diagnosis of mediastinal masses is currently a disputed subject.

  12. Assessment of Field Placement.

    ERIC Educational Resources Information Center

    Marshood, Nabil

    While field placement in human services programs is an extremely important practical phase of training, it has generally not been standardized, and thus can be difficult to assess. A model program and assessment format developed by Hudson County Community College (HCCC), in Jersey City, New Jersey, however, provides a possible framework for…

  13. Aerator Placement Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to determine the effects on fish production, water quality and economics of concentrating paddlewheel aeration in large commercial ponds, compared to the current method of aerator placement. Ten 17-acre ponds (approximately 600 X 1300 ft) were brought into the study in ...

  14. Research: Hyperactivity, Placement Centers

    ERIC Educational Resources Information Center

    Nation's Schools and Colleges, 1975

    1975-01-01

    A diet that emphasizes the elimination of food containing artificial coloring and flavoring from meals served to hyperactive children has met with success in preliminary studies; college placement centers are advised to shift their emphasis from job research and counseling. (Author/MLF)

  15. 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.

  16. Multi-resolution Gabor wavelet feature extraction for needle detection in 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; Mihajlovic, Nenad; de With, Peter H. N.; Huang, Jinfeng; Ng, Gary C.; Korsten, Hendrikus H. M.

    2015-12-01

    Ultrasound imaging is employed for needle guidance in various minimally invasive procedures such as biopsy guidance, regional anesthesia and brachytherapy. Unfortunately, a needle guidance using 2D ultrasound is very challenging, due to a poor needle visibility and a limited field of view. Nowadays, 3D ultrasound systems are available and more widely used. Consequently, with an appropriate 3D image-based needle detection technique, needle guidance and interventions may significantly be improved and simplified. In this paper, we present a multi-resolution Gabor transformation for an automated and reliable extraction of the needle-like structures in a 3D ultrasound volume. We study and identify the best combination of the Gabor wavelet frequencies. High precision in detecting the needle voxels leads to a robust and accurate localization of the needle for the intervention support. Evaluation in several ex-vivo cases shows that the multi-resolution analysis significantly improves the precision of the needle voxel detection from 0.23 to 0.32 at a high recall rate of 0.75 (gain 40%), where a better robustness and confidence were confirmed in the practical experiments.

  17. 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.

  18. Transrectal Prostate Biopsy and Fiducial Marker Placement in a Standard 1.5T Magnetic Resonance Imaging Scanner

    PubMed Central

    Susil, Robert C.; Ménard, Cynthia; Krieger, Axel; Coleman, Jonathan A.; Camphausen, Kevin; Choyke, Peter; Fichtinger, Gabor; Whitcomb, Louis L.; Coleman, C. Norman; Atalar, Ergin

    2012-01-01

    Purpose We investigated the accuracy and feasibility of a system that provides transrectal needle access to the prostate concurrent with 1.5 Tesla MRI which previously has not been possible. Materials and Methods In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures) and/or prostate biopsy (3 procedures) was performed using local anesthesia. Results Mean procedure duration was 76 minutes and all patients tolerated the intervention well. Procedure related adverse events included self-limited hematuria and hematochezia following 3 of 8 procedures (all resolved in less than 1 week). Mean needle placement accuracy was 1.9 mm for the fiducial marker placement studies and 1.8 mm for the biopsy procedures. Mean fiducial marker placement accuracy was 4.8 mm and the mean fiducial marker placement accuracy transverse to the needle direction was 2.6 mm. All patients who underwent the procedure were able to complete their course of radiotherapy without delay or complication. Conclusions While studies of clinical usefulness are warranted, transrectal 1.5 T MRI guided prostate biopsy and fiducial marker placement is feasible using this system, providing new opportunities for image guided diagnostic and therapeutic prostate interventions. PMID:16406885

  19. Safe use of subdermal needles for intraoperative monitoring with MRI.

    PubMed

    Darcey, Terrance M; Kobylarz, Erik J; Pearl, Michael A; Krauss, Patricia J; Ferri, Stephanie A; Roberts, David W; Bauer, David F

    2016-03-01

    OBJECTIVE The purpose of this study was to develop safe, site-specific procedures for placing and leaving subdermal needle leads for intraoperative monitoring (IOM) during intraoperative MRI procedures. METHODS The authors tested a variety of standard subdermal needle electrodes designed and FDA-approved for IOM in the conventional operating room. Testing was used to determine the conditions necessary to avoid thermal injury and significant image artifacts with minimal disruption of IOM and MRI procedures. Phantom testing was performed with a fiber optic (lead) temperature monitoring system and was followed by testing of leads placed in a healthy volunteer. The volunteer testing used electrode placements typical of standard IOM cases, together with radiofrequency (RF) coil placement and imaging sequences routinely employed for these case types. Lead length was investigated to assess heating effects for electrodes placed within the RF coil. RESULTS The authors found that conventional stainless steel (SS) and platinum/iridium (Pt/Ir) subdermal needles can be used safely without significant heating when placed outside the RF coil, and this accounts for the majority or entirety of electrode placements. When placed within the RF coil, Pt/Ir leads produced minimal image artifacts, while SS leads produced potentially significant artifacts. In phantom testing, significant heating was demonstrated in both SS and Pt/Ir leads placed within the RF coil, but only during high-resolution T2-weighted scanning. This problem was largely, but not completely, eliminated when leads were shortened to 25 cm. Human testing was unremarkable except for nonpainful heating detected in a few electrodes during thin-slice (1.5 mm) FLAIR scanning. Transient irritation (skin reddening along the needle tract) was noted at 2 of the electrodes with detectable heating. CONCLUSIONS The authors were satisfied with the safety of their site-specific procedures and have begun with off-label use (following

  20. Remote Subcutaneous Needling to Suppress the Irritability of Myofascial Trigger Spots: An Experimental Study in Rabbits

    PubMed Central

    Fu, Zhonghua; Hsieh, Yueh-Ling; Hong, Chang-Zern; Kao, Mu-Jung; Lin, Jaung-Geng; Chou, Li-Wei

    2012-01-01

    Objective. To obtain electrophysiological effects of Fu's subcutaneous needling (FSN) on needling distance by assessment of endplate noise (EPN) recorded from the myofascial trigger spots (MTrSs) in rabbit skeletal muscle. Method. Eighteen New Zealand rabbits weighing 2.5–3.0 kg were randomly divided into two groups as follows: proximal needling (PN) group and distal needling (DN) group. The needling procedure followed the instructions described by the inventor of FSN, including needling insertion and swaying movement. The amplitudes of EPN on the MTrS region of BF muscle were recorded as an index of MTrS irritability. Random sampling of EPN tracings were taken for further analyses before, during, and after FSN treatment. Results. In PN and DN groups, the trends of EPN amplitude alterations were similar at conditions before, during, and after FSN treatment. The degree of reduction in the EPN amplitude in PN group was significantly higher than that in DN group. There were no significant changes in EPN amplitudes in the MTrS of contralateral BF without FSN intervention either in DN or PN group. Conclusion. The irritability of proximal MTrSs could be modulated after ipsilateral FSNs. The placement of FSN may affect the effectiveness of suppression of irritability of MTrSs. PMID:23346200

  1. Design of a mechanical clutch-based needle-insertion device

    PubMed Central

    Bassett, Erik K.; Slocum, Alexander H.; Masiakos, Peter T.; Pryor, Howard I.; Farokhzad, Omid C.; Karp, Jeffery M.

    2009-01-01

    Insertion of trocars, needles, and catheters into unintended tissues or tissue compartments results in hundreds of thousands of complications annually. Current methods for blood vessel cannulation or epidural, chest tube, and initial trocar placement often involve the blind pass of a needle through several layers of tissue and generally rely on distinguishable anatomic landmarks and a high degree of clinical skill. To address this simply and without the use of electronics, a purely mechanical clutch system was developed for use in medical devices that access tissue and tissue compartments. This clutch utilizes the surface contact of a buckled filament inside an S-shaped tube to transmit force from the filament (catheter/guide wire) to the tube (needle). Upon encountering sufficient resistance at the tip, such as dense tissue, the catheter buckles and locks within the tube, causing the filament and needle to advance as one. When the needle reaches the target tissue or fluid-filled cavity, the filament unlocks and slides freely into the target region while the needle remains stationary. A similar locking phenomenon has long been observed in drill strings inside drill shafts used by the oil-drilling industry, and oil industry models were adapted to describe the motion of this clutch system. A predictive analytical model was generated and validated with empirical data and used to develop prototypes of a complete device then tested in vitro on muscle tissue and in vivo on a porcine laparoscopic model with promising results. PMID:19307560

  2. A Novel End-Effector Design for Robotics in Image Guided Needle Procedures

    PubMed Central

    Sun, David; Willingham, Chris; Durrani, Amir; King, Paul; Cleary, Kevin; Wood, Bradford

    2008-01-01

    Robotic end-effectors are being developed to facilitate image-guided minimally-invasive needle-based procedures such as tumor ablation, biopsy, thoracentesis, and blood sampling. A novel mechanical end-effector was designed to address the challenges associated with any major needle-based procedure, focusing on liver biopsy and ablation. In this end-effector embodiment, the distal end of a single articulating arm can grip needles and instruments and allow a fairly high number of degrees of freedom of movement during the complex motions associated with positioning and driving needles, as well as the periodic motions associated with breathing patterns. Tightening a cable that runs through the articulations fixes the arm in a rigid state, allowing insertion of the gripped needle. In its final form, we diagram a design that will require electro-mechanical stimulation and remote joystick control. Moreover, we discuss how cranial-caudal motion of soft tissue organs and the associated forces affect design constraints. A simulation protocol describes the use of tissue phantoms with mechanical properties in the range of hepatic tissue and the overlying abdominal wall. Finally, an in vivo protocol details the possible use of a robotic arm coupled with our end-effector in an image-guided interventional suite. Such a switchable and flexible mode for a robotic arm overcomes much of the current limitations for automated needle placements for mobile targets, subject to breathing or patient motion and the inherent risks thereof. PMID:17520618

  3. Simulations of needle insertion by using a Eulerian hydrocode FEM and the experimental validations.

    PubMed

    Kataoka, Hiroyuki; Noda, Shigeho; Yokota, Hideo; Takagi, Shu; Himeno, Ryutaro; Okazawa, Shigenobu

    2008-01-01

    In this paper, simulations for needle insertion were performed by using a novel Eulerian hydrocode FEM, which was adaptive for large deformation and tissue fracture. We also performed experiments for the same needle insertion with silicon rubbers and needles, which had conical tips of different angles in order to investigate the accuracy of the simulations. The resistance forces in the simulations accurately followed those in the experiments until the conical portion of the needle was inside the rubbers, and the validation of the Eulerian hydrocode was revealed. However, the present simulation showed that after the conical portion was inside the tissue, the simulated resistance forces became lower than the experimental ones. The proportional increase of the friction forces and the roughly flatness of the tip force along the time were simulated. It was predicted that the tightening force along the needle side was underestimated. PMID:18982649

  4. A randomised comparison between ultrasound and nerve stimulation for infraclavicular catheter placement.

    PubMed

    Dhir, S; Armstrong, K; Armstrong, P; Bouzari, A; Mall, J; Yu, J; Ganapathy, S; King, G

    2016-02-01

    We conducted this study to determine if placement of infraclavicular catheters guided by ultrasound is quicker than placement guided by nerve stimulation. Infraclavicular brachial plexus catheters were inserted in 210 randomly allocated patients who were scheduled for elective hand or elbow surgery. Needle and catheter placement was guided by ultrasound (n = 105) or by nerve stimulation (n = 105). The primary outcome was time to sensory block success. Success rate was similar between the two techniques (83.2% vs 81.4%, p = 0.738). However, placement of ultrasound-guided catheters took less time (7.2 [2.5] vs 9.6 [3.6] min, p < 0 .001). Pain and satisfaction scores, and incidence of nerve deficit, were also similar with both techniques. PMID:26566960

  5. 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

  6. 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

  7. 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

  8. Tumour seeding after fine-needle aspiration and core biopsy of the head and neck--a systematic review.

    PubMed

    Shah, Keval S V; Ethunandan, Madan

    2016-04-01

    Although fine-needle aspiration cytology (FNAC) and core needle biopsy are essential diagnostic investigations of lumps in the head and neck, seeding along the needle track has long been a concern, and various factors have been implicated. We therefore searched the Medline database for relevant English language papers published between 1970 and 2014, excluding those on the thyroid and parathyroid, and systematically reviewed them to assess the risk. In the 610 articles reviewed we found only 7 reports of seeding (5 after FNAC and 2 after core needle biopsy). Tumours were found between 3 months and 3 years after the procedure in 4 cases, and in 3, tumour cells were found along the needle track between 0 and 33 days after the procedure. The needles varied in size from 18 - 22 gauge (G) and there were 3 to 4 passes. Four cases occurred after investigation of a mass in the salivary glands, and 3 after assessment of a cervical lymph node. Disease was benign in one and malignant in 6. Seeding along the needle track after FNAC or core needle biopsy of a lump in the head and neck is rarely reported, and an accurate estimate of its incidence is difficult to ascertain. Crude estimates suggest 0.00012% and 0.0011% after FNA and core needle biopsy, respectively. A distinction should be made between seeding that is seen shortly after the procedure and the development of tumour along the needle track. PMID:26837638

  9. A Study of Placement Stability in Illinois. Chapin Hall Working Paper

    ERIC Educational Resources Information Center

    Zinn, Andrew; DeCoursey, Jan; Goerge, Robert M.; Courtney, Mark E.

    2006-01-01

    This report details the findings from the first stage of a study of placement instability in substitute care in Illinois. Funded by the Illinois Department of Children and Family Services (IDCFS), the goals of the study were to develop an accurate picture of the nature and prevalence of placement instability in Illinois and a better…

  10. 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.

  11. 7. View showing placement of timber deck placement on chord ...

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

    7. View showing placement of timber deck placement on chord and built up construction of top chord and continuous construction through top panel points, eye bar construction on bottom chord - Bridge No. 2.4, Spanning Boiling Fork Creek at Railroad Milepost JC-2.4, Decherd, Franklin County, TN

  12. Client-Centered Placement Revisited: A Dialogue on Placement Philosophy

    ERIC Educational Resources Information Center

    Salomone, Paul R.; Usdane, William M.

    1977-01-01

    The authors take substantially different philosophical stances concerning placement in the rehabilitation process. Usdane believes that job placement is not given enough attention by rehabilitation counselors early in the rehabilitation process. Salomone advocates a greater emphasis on client growth and independence. (Author)

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. Fine Needle Aspiration in Thyroid Nodules - One Year Experience

    PubMed Central

    Ahmeti, Irfan; Simonovska, Lliljana; Krstevska, Branka; Ristevska, Nevena

    2015-01-01

    AIM: To estimate suspect nodule for benign or malignant characteristics, and to verify cytological features of the node with the fine needle aspiration (FNA) under ultrasound. DESIGN: A total of 106 patients were analyzed. FNA biopsy was performed at outpatient clinic via ultrasound. Inform consent was signed for each patient. Preparation of procedure with local anaesthesia was made by assistant nurse. PROCEDURE: Parallel approach of ultrasound guided fine needle aspiration (USGFNA) was used for each patient. This approach allows the operator to observe needle penetration, location and pathway of the entire needle within the neck, thyroid and nodule, which remain visible on the monitor. As a side effect commonly noticed mild pain and dizziness were recorded. RESULTS: General findings: According the gender, 96 (90.5%) of them were women and 10 (9.5%) men. Median age was 47 ± 9 years. Cytological findings: 5 patients were with papillary carcinoma, 3 with Hurtle cell metaplasia, 1 follicular tumour and 1 with unclear differentiation. CONCLUSION: Close collaboration between endocrinologists, morphologists and surgeons in a multidisciplinary frame is the key to correct preoperative thyroid cancer diagnosis and optimal treatment. FNA biopsy remains the most accurate diagnostic method in detecting thyroid cancer.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  19. MAPP: A Mathematics Placement Program.

    ERIC Educational Resources Information Center

    Doblin, Stephen A.

    1978-01-01

    MAPP (A Mathematics Placement Program) uses two COBOL programs to place entering freshmen in mathematics courses which are commensurate with their backgrounds and abilities. Having been used for three years, the program is considered to be a viable alternative to the traditional mathematics placement process. (Author/JKS)

  20. Computerized Placement Tests: Background Readings.

    ERIC Educational Resources Information Center

    College Entrance Examination Board, Princeton, NJ.

    This document is a compilation of background readings for the user of Computerized Placement Tests (CPTs) developed by the College Board for student placement purposes. CPTs are computerized adaptive tests that test the individual abilities and backgrounds of examinees. CPTs are part of the ACCUPLACER student information management system. The…

  1. Improvement of Job Placement Services.

    ERIC Educational Resources Information Center

    Mount San Antonio Community Coll. District, Walnut, CA.

    The Improvement of Job Placement Services Project was undertaken to examine and strengthen job placement services and programs in the California community colleges. Specific objectives of the project were to: (1) select and convene a 12-member representative advisory committee to oversee project operations working with the California Placement…

  2. Job Placement Services Research Study.

    ERIC Educational Resources Information Center

    McLeod, Pat N.; Tobias, Jeanette

    A mailout questionnaire was used in a study which focused on three areas of inquiry: (1) Needs assessment for job placement programs in public schools as viewed by superintendents of school districts and vocational administrators of occupational programs, (2) assessment of the perceived and established benefits of a placement program from the…

  3. 30 CFR 57.22004 - Category placement or change in placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Category placement or change in placement. 57... placement or change in placement. The Administrator for Metal and Nonmetal Mine Safety and Health (Administrator) shall be responsible for category and subcategory placement, change in placement,...

  4. 30 CFR 57.22004 - Category placement or change in placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Category placement or change in placement. 57... placement or change in placement. The Administrator for Metal and Nonmetal Mine Safety and Health (Administrator) shall be responsible for category and subcategory placement, change in placement,...

  5. 30 CFR 57.22004 - Category placement or change in placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Category placement or change in placement. 57... placement or change in placement. The Administrator for Metal and Nonmetal Mine Safety and Health (Administrator) shall be responsible for category and subcategory placement, change in placement,...

  6. 30 CFR 57.22004 - Category placement or change in placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Category placement or change in placement. 57... placement or change in placement. The Administrator for Metal and Nonmetal Mine Safety and Health (Administrator) shall be responsible for category and subcategory placement, change in placement,...

  7. 30 CFR 57.22004 - Category placement or change in placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Category placement or change in placement. 57... placement or change in placement. The Administrator for Metal and Nonmetal Mine Safety and Health (Administrator) shall be responsible for category and subcategory placement, change in placement,...

  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. Comparison of the accuracy and proximal shunt failure rate of freehand placement versus intraoperative guidance in parietooccipital ventricular catheter placement.

    PubMed

    Wilson, Thomas J; McCoy, Kathleen E; Al-Holou, Wajd N; Molina, Sergio L; Smyth, Matthew D; Sullivan, Stephen E

    2016-09-01

    OBJECTIVE The aim of this paper is to compare the accuracy of the freehand technique versus the use of intraoperative guidance (either ultrasound guidance or frameless stereotaxy) for placement of parietooccipital ventricular catheters and to determine factors associated with reduced proximal shunt failure. METHODS This retrospective cohort study included all patients from 2 institutions who underwent a ventricular cerebrospinal fluid (CSF) shunting procedure in which a new parietooccipital ventricular catheter was placed between January 2005 and December 2013. Data abstracted for each patient included age, sex, method of ventricular catheter placement, side of ventricular catheter placement, Evans ratio, and bifrontal ventricular span. Postoperative radiographic studies were reviewed for accuracy of ventricular catheter placement. Medical records were also reviewed for evidence of shunt failure requiring revision. Standard statistical methods were used for analysis. RESULTS A total of 257 patients were included in the study: 134 from the University of Michigan and 123 from Washington University in St. Louis. Accurate ventricular catheter placement was achieved in 81.2% of cases in which intraoperative guidance was used versus 67.3% when the freehand technique was used. Increasing age reduced the likelihood of accurate catheter placement (OR 0.983, 95% CI 0.971-0.995; p = 0.005), while the use of intraoperative guidance significantly increased the likelihood (OR 2.809, 95% CI 1.406-5.618; p = 0.016). During the study period, 108 patients (42.0%) experienced shunt failure, 79 patients (30.7%) had failure involving the proximal catheter, and 53 patients (20.6%) had distal failure (valve or distal catheter). Increasing age reduced the likelihood of being free from proximal shunt failure (OR 0.983, 95% CI 0.970-0.995; p = 0.008), while both the use of intraoperative guidance (OR 2.385, 95% CI 1.227-5.032; p = 0.011), and accurate ventricular catheter placement (OR 3

  10. 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.

  11. Resuscitation in massive obstetric haemorrhage using an intraosseous needle.

    PubMed

    Chatterjee, D J; Bukunola, B; Samuels, T L; Induruwage, L; Uncles, D R

    2011-04-01

    A 38-year-old woman experienced a massive postpartum haemorrhage 30 minutes after emergency caesarean delivery. The patient became severely haemodynamically compromised with an unrecordable blood pressure. Rapid fluid resuscitation was limited by the capacity of the intravenous cannula in place at the time and inability to establish additional vascular access using conventional routes in a timely manner. An intraosseous needle was inserted in the proximal humerus at the first attempt and administration of resuscitation fluid by this route subsequently enabled successful placement of further intravenous lines. Blood and blood products were deployed in conjunction with intra-operative cell salvage and transoesophageal Doppler cardiac output monitoring was used to assess adequacy of volume replacement. Haemorrhage control was finally achieved with the use of recombinant factor VIIa and hysterectomy. PMID:21401545

  12. Endoscopic ultrasound-fine needle injection for oncological therapy

    PubMed Central

    Kaplan, Jeremy; Khalid, Amaara; Cosgrove, Natalie; Soomro, Ayesha; Mazhar, Syed Mohsin; Siddiqui, Ali A

    2015-01-01

    The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising. PMID:26691224

  13. PERTINENT DRY NEEDLING CONSIDERATIONS FOR MINIMIZING ADVERSE EFFECTS – PART ONE

    PubMed Central

    Halle, Rob J.

    2016-01-01

    ABSTRACT Background Dry needling is an evidence-based treatment technique that is accepted and used by physical therapists in the United States. This treatment approach focuses on releasing or inactivating muscular trigger points to decrease pain, reduce muscle tension, and assist patients with an accelerated return to active rehabilitation. Issue While commonly used, the technique has some patient risk and value of the treatment should be based on benefit compared to the potential risk. Adverse effects (AEs) with dry needling can be mild or severe, with overall incidence rates varying from zero to rates of approximately 10 percent. While mild AEs are the rule, any procedure that involves a needle insertion has the potential for an AE, with select regions and the underlying anatomy increasing the risk. Known significant AEs from small diameter needle insertion include pneumothorax, cardiac tamponade, hematoma, infection, central nervous system injury, and other complications. Purpose/Objective Underlying anatomy across individuals has variability, requiring an in-depth knowledge of anatomy prior to any needle placement. This commentary is an overview of pertinent anatomy in the region of the thorax, with a ‘part two’ that addresses the abdomen, pelvis, back, vasovagal response, informed consent and other pertinent issues. The purpose of the commentary is to minimize the risk of a dry needling AE. Conclusions/Implications Dry needling is an effective adjunct treatment procedure that is within the recognized scope of physical therapy practice. Physical therapy education and training provides practitioners with the anatomy, basic sciences, and clinical foundation to use this intervention safely and effectively. A safe and evidenced-based implementation of the procedure is based on a thorough understanding of the underlying anatomy and the potential risks, with risks coordinated with patients via informed consent. Levels of Evidence Level 5 PMID:27525188

  14. Conformal needle-based ultrasound ablation using EM-tracked conebeam CT image guidance

    NASA Astrophysics Data System (ADS)

    Burdette, E. Clif; Banovac, Filip; Diederich, Chris J.; Cheng, Patrick; Wilson, Emmanuel; Cleary, Kevin R.

    2011-03-01

    Numerous studies have demonstrated the efficacy of interstitial ablative approaches for the treatment of renal and hepatic tumors. Despite these promising results, current systems remain highly dependent on operator skill, and cannot treat many tumors because there is little control of the size and shape of the zone of necrosis, and no control over ablator trajectory within tissue once insertion has taken place. Additionally, tissue deformation and target motion make it extremely difficult to accurately place the ablator device into the target. Irregularly shaped target volumes typically require multiple insertions and several sequential thermal ablation procedures. This study demonstrated feasibility of spatially tracked image-guided conformal ultrasound (US) ablation for percutaneous directional ablation of diseased tissue. Tissue was prepared by suturing the liver within a pig belly and 1mm BBs placed to serve as needle targets. The image guided system used integrated electromagnetic tracking and cone-beam CT (CBCT) with conformable needlebased high-intensity US ablation in the interventional suite. Tomographic images from cone beam CT were transferred electronically to the image-guided tracking system (IGSTK). Paired-point registration was used to register the target specimen to CT images and enable navigation. Path planning is done by selecting the target BB on the GUI of the realtime tracking system and determining skin entry location until an optimal path is selected. Power was applied to create the desired ablation extent within 7-10 minutes at a thermal dose (>300eqm43). The system was successfully used to place the US ablator in planned target locations within ex-vivo kidney and liver through percutaneous access. Targeting accuracy was 3-4 mm. Sectioned specimens demonstrated uniform ablation within the planned target zone. Subsequent experiments were conducted for multiple ablator positions based upon treatment planning simulations. Ablation zones in

  15. 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.

  16. Automatic needle segmentation in 3D ultrasound images using 3D Hough transform

    NASA Astrophysics Data System (ADS)

    Zhou, Hua; Qiu, Wu; Ding, Mingyue; Zhang, Songgeng

    2007-12-01

    3D ultrasound (US) is a new technology that can be used for a variety of diagnostic applications, such as obstetrical, vascular, and urological imaging, and has been explored greatly potential in the applications of image-guided surgery and therapy. Uterine adenoma and uterine bleeding are the two most prevalent diseases in Chinese woman, and a minimally invasive ablation system using an RF button electrode which is needle-like is being used to destroy tumor cells or stop bleeding currently. Now a 3D US guidance system has been developed to avoid accidents or death of the patient by inaccurate localizations of the electrode and the tumor position during treatment. In this paper, we described two automated techniques, the 3D Hough Transform (3DHT) and the 3D Randomized Hough Transform (3DRHT), which is potentially fast, accurate, and robust to provide needle segmentation in 3D US image for use of 3D US imaging guidance. Based on the representation (Φ , θ , ρ , α ) of straight lines in 3D space, we used the 3DHT algorithm to segment needles successfully assumed that the approximate needle position and orientation are known in priori. The 3DRHT algorithm was developed to detect needles quickly without any information of the 3D US images. The needle segmentation techniques were evaluated using the 3D US images acquired by scanning water phantoms. The experiments demonstrated the feasibility of two 3D needle segmentation algorithms described in this paper.

  17. Phase grouping-based needle segmentation in 3-D trans-rectal ultrasound-guided prostate trans-perineal therapy.

    PubMed

    Qiu, Wu; Yuchi, Ming; Ding, Mingyue

    2014-04-01

    A robust and efficient needle segmentation method used to localize and track the needle in 3-D trans-rectal ultrasound (TRUS)-guided prostate therapy is proposed. The algorithmic procedure begins by cropping the 3-D US image containing a needle; then all voxels in the cropped 3-D image are grouped into different line support regions (LSRs) based on the outer product of the adjacent voxels' gradient vector. Two different needle axis extraction methods in the candidate LSR are presented: least-squares fitting and 3-D randomized Hough transform. Subsequent local optimization refines the position of the needle axis. Finally, the needle endpoint is localized by finding an intensity drop along the needle axis. The proposed methods were validated with 3-D TRUS tissue-mimicking agar phantom images, chicken breast phantom images and patient images obtained during prostate cryotherapy. The results of the in vivo test indicate that our method can localize the needle accurately and robustly with a needle endpoint localization accuracy <1.43 mm and detection accuracy >84%, which are favorable for 3-D TRUS-guided prostate trans-perineal therapy. PMID:24462163

  18. Thermomechanical characterization of one-way shape memory Nitinol as an actuator for active surgical needle

    NASA Astrophysics Data System (ADS)

    Honarvar, Mohammad

    Needle-based intervention insertion is one of the common surgical techniques used in many diagnostic and therapeutic percutaneous procedures. The success of such procedures highly depends on the accuracy of needle placement at target locations. An active needle has the potential to enhance the accuracy of needle placement as well as to improve clinical outcome. Bending forces provided by the attached actuators can assist the maneuverability in order to reach the targets following a desired trajectory. There are three major research parts in the development of active needle project in the Composites Laboratory of Temple University. They are thermomechanical characterization of shape memory alloy (SMA) or Nitinol as an actuator for smart needle, mechanical modeling and design of smart needles, and study of tissue needle interaction. The characterization of SMA is the focus of this dissertation. Unique thermomechanical properties of Nitinol known as shape memory effect and superelasticity make it applicable for different fields such as biomedical, structural and aerospace engineering. These unique behaviors are due to the comparatively large amount of recoverable strain which is being produced in a martensitic phase transformation. However, under certain ranges of stresses and temperatures, Nitinol wires exhibit unrecovered strain (also known as residual strain); which limits their applicability. Therefore, for applications that rely on the strain response in repetitive loading and unloading cycles, it is important to understand the generation of the unrecovered strain in the Nitinol wires. In this study, the unrecovered strain of Nitinol wires with various diameters was investigated, using two experimental approaches: constant stress and uniaxial tensile tests. Moreover, a critical range of stress was found beyond which the unrecovered strain was negligible at temperatures of 70 to 80°C depending on the wire diameter. Wire diameters varied from 0.10 to 0.29 mm were

  19. Needle segmentation using 3D Hough transform in 3D TRUS guided prostate transperineal therapy

    SciTech Connect

    Qiu Wu; Yuchi Ming; Ding Mingyue; Tessier, David; Fenster, Aaron

    2013-04-15

    Purpose: Prostate adenocarcinoma is the most common noncutaneous malignancy in American men with over 200 000 new cases diagnosed each year. Prostate interventional therapy, such as cryotherapy and brachytherapy, is an effective treatment for prostate cancer. Its success relies on the correct needle implant position. This paper proposes a robust and efficient needle segmentation method, which acts as an aid to localize the needle in three-dimensional (3D) transrectal ultrasound (TRUS) guided prostate therapy. Methods: The procedure of locating the needle in a 3D TRUS image is a three-step process. First, the original 3D ultrasound image containing a needle is cropped; the cropped image is then converted to a binary format based on its histogram. Second, a 3D Hough transform based needle segmentation method is applied to the 3D binary image in order to locate the needle axis. The position of the needle endpoint is finally determined by an optimal threshold based analysis of the intensity probability distribution. The overall efficiency is improved through implementing a coarse-fine searching strategy. The proposed method was validated in tissue-mimicking agar phantoms, chicken breast phantoms, and 3D TRUS patient images from prostate brachytherapy and cryotherapy procedures by comparison to the manual segmentation. The robustness of the proposed approach was tested by means of varying parameters such as needle insertion angle, needle insertion length, binarization threshold level, and cropping size. Results: The validation results indicate that the proposed Hough transform based method is accurate and robust, with an achieved endpoint localization accuracy of 0.5 mm for agar phantom images, 0.7 mm for chicken breast phantom images, and 1 mm for in vivo patient cryotherapy and brachytherapy images. The mean execution time of needle segmentation algorithm was 2 s for a 3D TRUS image with size of 264 Multiplication-Sign 376 Multiplication-Sign 630 voxels. Conclusions

  20. PMU Placement for Dynamic State Tracking of Power Systems

    SciTech Connect

    Sun, Yannan; Du, Pengwei; Huang, Zhenyu; Kalsi, Karanjit; Diao, Ruisheng; Anderson, Kevin K.; Li, Yulan; Lee, Barry

    2011-08-04

    Accurately tracking the state variables (rotor angle and speed) is a necessity for monitoring system stability conditions and assessing the risks of large-scale system collapse. This paper explores how the number and locations of PMUs installed in the system are determined to ensure satisfactory state tracking performance. A search algorithm is presented for determining PMU placement (location and quantity). The algorithm determines a placement that gives small tracking error in polynomial time. A modified, scalable algorithm is also presented. Observability in the presence of faults is considered. Simulation results for a 16-machine and a 50-machine system are provided.

  1. Learning Ultrasound-Guided Needle Insertion Skills through an Edutainment Game

    NASA Astrophysics Data System (ADS)

    Chan, Wing-Yin; Ni, Dong; Pang, Wai-Man; Qin, Jing; Chui, Yim-Pan; Yu, Simon Chun-Ho; Heng, Pheng-Ann

    Ultrasound-guided needle insertion is essential in many of minimally invasive surgeries or procedures, such as biopsy, drug delivery, spinal anaesthesia, etc. Accurate and safe needle insertion is a difficult task due to the high requirement of hand-eye coordination skills. Many proposed virtual reality (VR) based training systems put their emphasis on realistic simulation instead of pedagogical efficiency. The lack of schematic training scenario leads to boredom of repetitive operations. To solve this, we present our novel training system with the integration of game elements in order to retain the trainees' enthusiasm. Task-oriented scenarios, time attack scenarios and performance evaluation are introduced. Besides, some state-of-art technologies are also presented, including ultrasound simulation, needle haptic rendering as well as a mass-spring-based needle-tissue interaction simulation. These works are shown to be effective to keep the trainees up with learning.

  2. Design and in vivo evaluation of a robotized needle insertion system for small animals.

    PubMed

    Goffin, Laurent; Bour, Gaetan; Martel, Fernand; Nicolau, Stephane; Gangloff, Jacques; Egly, Jean-Marc; Bayle, Bernard

    2013-08-01

    The development of imaging devices adapted to small animals has opened the way to image-guided procedures in biomedical research. In this paper, we focus on automated procedures to study the effects of the recurrent administration of substances to the same animal over time. A dedicated system and the associated workflow have been designed to percutaneously position a needle into the abdominal organs of mice. Every step of the procedure has been automated: the camera calibration, the needle access planning, the robotized needle positioning, and the respiratory-gated needle insertion. Specific devices have been developed for the registration, the animal binding under anesthesia, and the skin puncture. Among the presented results, the system accuracy is particularly emphasized, both in vitro using gelose phantoms and in vivo by injecting substances into various abdominal organs. The study shows that robotic assistance could be routinely used in biomedical research laboratories to improve existing procedures, allowing automated accurate treatments and limited animal sacrifices. PMID:23475327

  3. Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system

    PubMed Central

    Kuo, Wei-Cheng; Kim, Jongsik; Shemonski, Nathan D.; Chaney, Eric J.; Spillman, Darold R.; Boppart, Stephen A.

    2012-01-01

    Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed that incorporates both three-dimensional OCT imaging and tissue biopsy within the same needle for true OCT-guided core-needle biopsy. We have developed and demonstrate an integrated core-needle biopsy system that utilizes catheter-based 3-D OCT for real-time image-guidance for target tissue localization, imaging of tissue immediately prior to physical biopsy, and subsequent OCT imaging of the biopsied specimen for immediate assessment at the point-of-care. OCT images of biopsied ex vivo tumor specimens acquired during core-needle placement are correlated with corresponding histology, and computational visualization of arbitrary planes within the 3-D OCT volumes enables feedback on specimen tissue type and biopsy quality. These results demonstrate the potential for using real-time 3-D OCT for needle biopsy guidance by imaging within the needle and tissue during biopsy procedures. PMID:22741064

  4. Combining Cooperative Education and Placement.

    ERIC Educational Resources Information Center

    Lentz, Glenda F.

    1984-01-01

    Suggests that placement, like cooperative education, can function better in academic affairs rather than student affairs. Describes the combination of the two departments at the University of South Florida and discusses advantages and disadvantages of a combined program. (JAC)

  5. 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

  6. K.s. Micro-implant placement guide.

    PubMed

    Sharma, K; Sangwan, A

    2014-09-01

    A one of the greatest concerns with orthodontic mini-implants is risk of injury to dental roots during placement is, especially when they are inserted between teeth. Many techniques have been used to facilitate safe placement of interradicular miniscrews. Brass Wires or metallic markers are easy to place in the interproximal spaces, but because their relative positions may be inconsistent in different radio -graphic views, they are not always accurate. K.S. micro implant placement guide suggested in this article is simple design and easy in fabrication, required minimal equipment for fabrication and does not disturb the existing appliance system, clearly located in the radiograph and the mini-screw can be easily inserted through the guide reducing the chance of implant misplacement. PMID:25364613

  7. K.S. Micro-Implant Placement Guide

    PubMed Central

    Sharma, K; Sangwan, A

    2014-01-01

    A one of the greatest concerns with orthodontic mini-implants is risk of injury to dental roots during placement is, especially when they are inserted between teeth. Many techniques have been used to facilitate safe placement of interradicular miniscrews. Brass Wires or metallic markers are easy to place in the interproximal spaces, but because their relative positions may be inconsistent in different radio -graphic views, they are not always accurate. K.S. micro implant placement guide suggested in this article is simple design and easy in fabrication, required minimal equipment for fabrication and does not disturb the existing appliance system, clearly located in the radiograph and the mini-screw can be easily inserted through the guide reducing the chance of implant misplacement. PMID:25364613

  8. 34 CFR 300.327 - Educational placements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Educational placements. 300.327 Section 300.327... Educational Placements Development of Iep § 300.327 Educational placements. Consistent with § 300.501(c), each... makes decisions on the educational placement of their child. (Authority: 20 U.S.C. 1414(e))...

  9. A blunt needle (Epimed®) does not eliminate the risk of vascular penetration during transforaminal epidural injection

    PubMed Central

    Ilkhchoui, Yashar; Koshkin, Eugene

    2013-01-01

    Background: Transforaminal epidural injection of local anesthetics and corticosteroids is a common practice in patients with radicular pain. However, serious morbidity has also been reported, which can be attributed to an arterial or venous injection of the medication especially particulate glucocorticoid preparations. Using a blunt needle in contrast to sharp needle has been suggested to reduce this risk in a study on animals. Case Description: We present a 59-year-old female with L5 lumbar radicular symptoms and left L5-S1 foraminal narrowing who underwent transforaminal epidural injection with fluoroscopic guidance using a 22-gauge blunt curved needle (Epimed®, Johnstown, NY). Intravascular needle placement was detected during real-time contrast injection under live fluoroscopy after a negative aspiration and local anesthetic test dose. The needle was slightly withdrawn and correct distribution of the contrast was confirmed along the target nerve root and into the epidural space. Conclusion: This case report discusses vascular penetration utilizing an Epimed® blunt needle to perform transforaminal injections in a clinical setting. This topic was previously discussed in earlier animal studies. We also reemphasize that neither negative aspiration or local anesthetic test doses are reliable techniques to ensure the safety of transforaminal epidural injections. PMID:24340239

  10. Use of frameless neuronavigation for bedside placement of external ventricular catheters.

    PubMed

    Glenn, Chad A; Conner, Andrew K; Cheema, Ahmed A; Burks, Joshua D; Case, Justin L; O'Neal, Christen; Sughrue, Michael E

    2016-04-01

    Neuronavigation for placement of ventricular catheters has been described. At our institution, electromagnetic neuronavigation is frequently utilized for difficult ventricular catheter placement. In patients who develop a trapped ventricle as a result of an intraparenchymal or intraventricular mass lesion, successful catheter placement may be difficult, as the location and trajectory are unfamiliar. The authors report their experience using electromagnetic neuronavigation for bedside placement of external ventricular catheters in patients with trapped ventricles. The technique for bedside placement of external ventricular catheters utilizing electromagnetic neuronavigation is reviewed. The benefits of this technique and those patients in whom it may be most useful are discussed. Utilization of bedside electromagnetic neuronavigation for placement of difficult external ventricular catheters into trapped ventricles is an option for accurate navigated catheter placement. Bedside electromagnetic neuronavigation offers accurate catheter placement in awake patients. This technique may be utilized in patients with high perioperative risk factors as it does not require general anesthesia. The procedure is well tolerated as it does not require rigid head fixation. PMID:26642952

  11. Dry Ribbon for Heated Head Automated Fiber Placement

    NASA Technical Reports Server (NTRS)

    Hulcher, A. Bruce; Marchello, Joseph M.; Hinkley, Jeffrey A.; Johnston, Norman J.; Lamontia, Mark A.

    2000-01-01

    Ply-by-ply in situ processes involving automated heated head deposition are being developed for fabrication of high performance, high temperature composite structures from low volatile content polymer matrices. This technology requires (1) dry carbon fiber towpreg, (2) consolidation of towpreg to quality, placement-grade unidirectional ribbon or tape, and (3) rapid, in situ, accurate, ply-by-ply robotic placement and consolidation of this material to fabricate a composite structure. In this study, the physical properties of a candidate thermoplastic ribbon, PIXA/IM7, were evaluated and screened for suitability in robotic placement. Specifically, towpreg was prepared from PIXA powder. Various conditions (temperatures) were used to convert the powder-coated towpreg to ribbons with varying degrees of processability. Ribbon within preset specifications was fabricated at 3 temperatures: 390, 400 and 410 C. Ribbon was also produced out-of-spec by purposely overheating the material to a processing temperature of 450 C. Automated placement equipment at Cincinnati Milacron and NASA Langley was used to fabricate laminates from these experimental ribbons. Ribbons were placed at 405 and 450 C by both sets of equipment. Double cantilever beam and wedge peel tests were used to determine the quality of the laminates and, especially, the interlaminar bond formed during the placement process. Ribbon made under conditions expected to be non-optimal (overheated) resulted in poor placeability and composites with weak interlaminar bond strengths, regardless of placement conditions. Ribbon made under conditions expected to be ideal showed good processability and produced well-consolidated laminates. Results were consistent from machine to machine and demonstrated the importance of ribbon quality in heated-head placement of dry material forms. Preliminary screening criteria for the development and evaluation of ribbon from new matrix materials were validated.

  12. 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...

  13. 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

  14. Needle localization using a moving stylet/catheter in ultrasound-guided regional anesthesia: a feasibility study

    NASA Astrophysics Data System (ADS)

    Beigi, Parmida; Rohling, Robert

    2014-03-01

    Despite the wide range and long history of ultrasound guided needle insertions, an unresolved issue in many cases is clear needle visibility. A well-known ad hoc technique to detect the needle is to move the stylet and look for changes in the needle appearance. We present a new method to automatically locate a moving stylet/catheter within a stationary cannula using motion detection. We then use this information to detect the needle trajectory and the tip. The differences between the current frame and the previous frame are detected and localized, to minimize the influence of tissue global motions. A polynomial fit based on the detected needle axis determines the estimated stylet shaft trajectory, and the extent of the differences along the needle axis represents the tip. Over a few periodic movements of the stylet including its full insertion into the cannula to the tip, a combination of polynomial fits determines the needle trajectory and the last detected point represents the needle tip. Experiments are conducted in water bath and bovine muscle tissue for several stylet/catheter materials. Results show that a plastic stylet has the best needle shaft and tip localization accuracy in the water bath with RMSE = 0:16 mm and RMSE = 0:51 mm, respectively. In the bovine tissue, the needle tip was best localized with the plastic catheter with RMSE = 0:33 mm. The stylet tip localization was most accurate with the steel stylet, with RMSE = 2:81 mm and the shaft was best localized with the plastic catheter, with RMSE = 0:32 mm.

  15. [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

  16. 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 ...

  17. Optimizing prostate needle biopsy through 3D simulation

    NASA Astrophysics Data System (ADS)

    Zeng, Jianchao; Kaplan, Charles; Xuan, Jian Hua; Sesterhenn, Isabell A.; Lynch, John H.; Freedman, Matthew T.; Mun, Seong K.

    1998-06-01

    Prostate needle biopsy is used for the detection of prostate cancer. The protocol of needle biopsy that is currently routinely used in the clinical environment is the systematic sextant technique, which defines six symmetric locations on the prostate surface for needle insertion. However, this protocol has been developed based on the long-term observation and experience of urologists. Little quantitative or scientific evidence supports the use of this biopsy technique. In this research, we aim at developing a statistically optimized new prostate needle biopsy protocol to improve the quality of diagnosis of prostate cancer. This new protocol will be developed by using a three-dimensional (3-D) computer- based probability map of prostate cancer. For this purpose, we have developed a computer-based 3-D visualization and simulation system with prostate models constructed from the digitized prostate specimens, in which the process of prostate needle biopsy can be simulated automatically by the computer. In this paper, we first develop an interactive biopsy simulation mode in the system, and evaluate the performance of the automatic biopsy simulation with the sextant biopsy protocol by comparing the results by the urologist using the interactive simulation mode with respect to 53 prostate models. This is required to confirm that the automatic simulation is accurate and reliable enough for the simulation with respect to a large number of prostate models. Then we compare the performance of the existing protocols using the automatic biopsy simulation system with respect to 107 prostate models, which will statistically identify if one protocol is better than another. Since the estimation of tumor volume is extremely important in determining the significance of a tumor and in deciding appropriate treatment methods, we further investigate correlation between the tumor volume and the positive core volume with 89 prostate models. This is done in order to develop a method to

  18. Consistency of lumbar discograms of the same disc obtained twice at a 2-week interval: influence of needle tip position.

    PubMed

    Urasaki, T; Muro, T; Ito, S; Hattori, Y; Ozaki, S

    1998-01-01

    : Although numerous papers have emphasized the importance of accurate needle positioning in lumbar discography, no concrete evidence is available to support this contention, and no study has evaluated the image consistency of discography as influenced by this factor. By observing the consistency of two images in relation to needle tip position we aimed to clarify the importance of needle positioning in discography. One hundred and ninety-two patients (324 discs) receiving steroid intradiscal therapy in whom discography of the same disc was performed twice at a 2-week interval and in whom the needle tip position was within the acceptable range (as defined by us) were studied. The patients were divided into two groups: in group G, in whom the needle tip was within a limited range on both discograms, and group P, in whom the needle tip was in this range on only one discogram. Image consistency was compared roentgenographically in the two groups. The consistent image rate for the total number of discs was 48.5%, being significantly higher in group G (53.2%) than in group P (39.0%). The rates were lower in the nucleus pulposus and the posterior portion of the disc than in the other disc areas, but were significantly higher in group G (85. 4% and 75.0%, respectively, for these two areas). The necessity for accurate needle tip positioning was proved roentgenographically. PMID:9732558

  19. Teleoperation System with Hybrid Pneumatic-Piezoelectric Actuation for MRI-Guided Needle Insertion with Haptic Feedback

    PubMed Central

    Shang, Weijian; Su, Hao; Li, Gang; Fischer, Gregory S.

    2014-01-01

    This paper presents a surgical master-slave tele-operation system for percutaneous interventional procedures under continuous magnetic resonance imaging (MRI) guidance. This system consists of a piezoelectrically actuated slave robot for needle placement with integrated fiber optic force sensor utilizing Fabry-Perot interferometry (FPI) sensing principle. The sensor flexure is optimized and embedded to the slave robot for measuring needle insertion force. A novel, compact opto-mechanical FPI sensor interface is integrated into an MRI robot control system. By leveraging the complementary features of pneumatic and piezoelectric actuation, a pneumatically actuated haptic master robot is also developed to render force associated with needle placement interventions to the clinician. An aluminum load cell is implemented and calibrated to close the impedance control loop of the master robot. A force-position control algorithm is developed to control the hybrid actuated system. Teleoperated needle insertion is demonstrated under live MR imaging, where the slave robot resides in the scanner bore and the user manipulates the master beside the patient outside the bore. Force and position tracking results of the master-slave robot are demonstrated to validate the tracking performance of the integrated system. It has a position tracking error of 0.318mm and sine wave force tracking error of 2.227N. PMID:25126446

  20. 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.

  1. 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.

  2. Localization of needle tip with color doppler during pericardiocentesis: In vitro validation and initial clinical application

    NASA Technical Reports Server (NTRS)

    Armstrong, G.; Cardon, L.; Vilkomerson, D.; Lipson, D.; Wong, J.; Rodriguez, L. L.; Thomas, J. D.; Griffin, B. P.

    2001-01-01

    This study evaluates a new device that uses color Doppler ultrasonography to enable real-time image guidance of the aspirating needle, which has not been possible until now. The ColorMark device (EchoCath Inc, Princeton, NJ) induces high-frequency, low-amplitude vibrations in the needle to enable localization with color Doppler. We studied this technique in 25 consecutive patients undergoing pericardiocentesis, and in vitro, in a urethane phantom with which the accuracy of color Doppler localization of the needle tip was compared with that obtained by direct measurement. Tip localization was excellent in vitro; errors axial to the ultrasound beam (velocity Doppler -0.13 +/- 0.90 mm, power Doppler -0.05 +/- 1.7 mm) were less than lateral errors (velocity -0.36 +/- 1.8 mm, power -0.02 +/- 2.8 mm). In 18 of 25 patients, the needle was identified and guided into the pericardial space with the ColorMark technique, and it allowed successful, uncomplicated drainage of fluid. Initial failures were the result of incorrect settings on the echocardiographic machine and inappropriate combinations of the needle puncture site and imaging window. This study demonstrates a novel color Doppler technique that is highly accurate at localizing a needle tip. The technique is feasible for guiding pericardiocentesis. Further clinical validation of this technique is required.

  3. Controllable design of super-oscillatory planar lenses for sub-diffraction-limit optical needles.

    PubMed

    Diao, Jinshuai; Yuan, Weizheng; Yu, Yiting; Zhu, Yechuan; Wu, Yan

    2016-02-01

    Sub-diffraction-limit optical needle can be created by a binary amplitude mask through tailoring the interference of diffraction beams. In this paper, a controllable design of super-oscillatory planar lenses to create sub-diffraction-limit optical needles with the tunable focal length and depth of focus (DOF) is presented. As a high-quality optical needle is influenced by various factors, we first propose a multi-objective and multi-constraint optimization model compromising all the main factors to achieve a needle with the prescribed characteristics. The optimizing procedure is self-designed using the Matlab programming language based on the genetic algorithm (GA) and fast Hankel transform algorithm. Numerical simulations show that the optical needles' properties can be controlled accurately. The optimized results are further validated by the theoretical calculation with the Rayleigh-Sommerfeld integral. The sub-diffraction-limit optical needles can be used in wide fields such as optical nanofabrication, super-resolution imaging, particle acceleration and high-density optical data storage. PMID:26906769

  4. 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....

  5. 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…

  6. [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

  7. Investigating the Possibility of Using TOEFL Scores for University ESL Decision-Making: Placement Trends and Effect of Time Lag

    ERIC Educational Resources Information Center

    Kokhan, Kateryna

    2012-01-01

    The English Placement Test (EPT) at the University of Illinois at Urbana-Champaign (UIUC) is designed to provide an accurate placement (or exemption) of international students into the ESL writing and pronunciation classes. Over the last five years, UIUC has experienced an increase in the number of international students taking the EPT. Because of…

  8. Short, multi-needle FDR sensor suitable for measuring soil water content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Time domain reflectometry (TDR) is a well-established electromagnetic technique used to measure soil water content. TDR sensors have been combined with heat pulse sensors to produce thermo-TDR sensors. Thermo-TDR sensors are restricted to having relatively short needles in order to accurately measur...

  9. The current role of percutaneous needle biopsies of renal tumours.

    PubMed

    Volpe, Alessandro; Terrone, Carlo; Scarpa, Roberto M

    2009-06-01

    The role of percutaneous biopsy of renal masses has been traditionally limited by concerns about its safety, accuracy and sampling errors. The increasing incidence in the diagnosis of incidental small renal masses (SRMs), the development of conservative and minimally invasive treatments for low risk renal cell carcinomas (RCCs) and the discovery of novel targeted treatments for metastatic disease are now leading to wider indications for renal tumor biopsy. Percutaneous biopsy of renal tumors can be performed in an outpatient setting under ultrasound and/or CT guidance. 18 gauge needles loaded in an automatic biopsy gun are used to retrieve cores and 21 gauge needles to obtain FNA specimens through a 17 gauge coaxial cannula placed close to the tumor. A careful check of the quality of biopsies and aspirates is paramount to maximize the diagnostic yield of the procedure. With the development of new biopsy techniques the risk of tumor seeding appears negligible and significant bleeding is unusual and very rarely clinically significant. In centres with expertise, needle core biopsy with or without FNA can provide adequate specimens for an accurate diagnosis in over 90% of cases. Incidental SRMs are frequently detected in elderly patients and have a very heterogeneous biological behaviour At surgery up to one third have benign histologies and most of those that are malignant are low grade RCCs. Pretreatment percutaneous biopsy can significantly decrease the number of unnecessary surgeries for benign disease and assist the urologist in clinical decision making, especially for elderly and unfit patients who are possible candidates for active surveillance and/or minimally invasive ablative therapies. Finally, there is potential for stratifying initial therapy of metastatic RCC by histological subtype on needle biopsies. PMID:19760866

  10. Fine-Needle Aspiration Followed by Core-Needle Biopsy in the Same Setting: Modifying Our Approach.

    PubMed

    Joudeh, Amani A; Shareef, Sameera Q; Al-Abbadi, Mousa A

    2016-01-01

    Fine-needle aspiration biopsy (FNAB) is a well-established initial diagnostic tool. However, in some instances limitations and shortcomings arise, making it insufficient for determining a specific diagnosis. Consequently, patients have to undergo another diagnostic procedure. The second procedure is either repeat FNAB, core-needle or open biopsy, and can be inconvenient and costly. In some centers, the FNAB is immediately followed by core-needle biopsy (CNB) in the same setting after assuring adequacy on the initial FNAB utilizing rapid on-site specimen evaluation (ROSE). It is argued that implementing such an approach will eventually have additional critical advantages that include the following: (a) it is more convenient to patients to have both procedures in one visit, (b) the tissue procured by both procedures will be more adequate, enabling cytopathologists to reach an accurate diagnosis, and (c) it is ultimately a cost-effective approach if we take into consideration the avoidance of a potential second more invasive diagnostic procedure. Since we are living in an era of patient-centered medicine coupled with cost-cutting strategies, we present here a brief review of the topic with analysis of this alternative approach, review of the pertinent literature and shed light on a few scenarios that justify this approach. PMID:26963594

  11. 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

  12. 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

  13. 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

  14. Extension for prevention: margin placement.

    PubMed

    Larson, Thomas D

    2012-01-01

    This article will review the concept of extension for prevention popularized by G.V. Black around the early 1900s. Concepts of extension and prevention have changed over the years with a more informed knowledge of the caries process, improved materials, cutting instruments, and techniques. The reasons for placement of the outline form relative to the tooth morphology, gingival tissue, relationship to adjacent teeth, and the choice of material will be described for all of the materials used in restorative dentistry. Research will be cited to support the scientific basis for outline form placement. PMID:22662468

  15. Optimum placement of controls for static deformations of space structures

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.

    1984-01-01

    Many large space structures, such as large antennas, have to maintain a fairly exact shape to operate satisfactorily. Such structures require active and passive controls to maintain their accurate shape under disturbances. The present paper is concerned with optimum placement of controls for correcting static deformations. Both force actuators and heaters are considered for controls. A formulation of design against the worst disturbance is derived. A beam example is employed to demonstrate the procedure.

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

    PubMed Central

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

    2012-01-01

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

  17. 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

  18. A contrast and registration template for magnetic resonance image data guided dental implant placement

    NASA Astrophysics Data System (ADS)

    Eggers, Georg; Cosgarea, Raluca; Rieker, Marcus; Kress, Bodo; Dickhaus, Hartmut; Mühling, Joachim

    2009-02-01

    An oral imaging template was developed to address the shortcomings of MR image data for image guided dental implant planning and placement. The template was conctructed as a gadolinium filled plastic shell to give contrast to the dentition and also to be accurately re-attachable for use in image guided dental implant placement. The result of segmentation and modelling of the dentition from MR Image data with the template was compared to plaster casts of the dentition. In a phantom study dental implant placement was performed based on MR image data. MR imaging with the contrast template allowed complete representation of the existing dentition. In the phantom study, a commercially available system for image guided dental implant placement was used. Transformation of the imaging contrast template into a surgical drill guide based on the MR image data resulted in pilot burr hole placement with an accuracy of 2 mm. MRI based imaging of the existing dentition for proper image guided planning is possible with the proposed template. Using the image data and the template resulted in less accurate pilot burr hole placement in comparison to CT-based image guided implant placement.

  19. 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

  20. Advanced Placement: Access Not Exclusion.

    ERIC Educational Resources Information Center

    Camara, Wayne; Dorans, Neil J.; Morgan, Rick; Myford, Carol

    2000-01-01

    Refutes the assertion by W. Lichten (2000) that increased access to advanced placement (AP) courses in high school has led to a decline in AP quality. Suggests that increased access exposes students to college-level course material, encourages teachers to expand their knowledge domains, increases curriculum rigor, and give students new challenges.…

  1. Advanced Placement Course Description. Statistics.

    ERIC Educational Resources Information Center

    College Entrance Examination Board, New York, NY.

    The Advanced Placement (AP) program is a cooperative educational effort of secondary schools, colleges, and the College Board that consists of 30 college-level courses and examinations in 17 academic disciplines for highly motivated students in secondary schools. AP courses are offered in more than 11,000 high schools and are recognized by nearly…

  2. The Placement Professional as Marketeer.

    ERIC Educational Resources Information Center

    Walz, Garry R.

    1988-01-01

    Discusses resistance of helping professions to marketing. Defines human services marketing. Describes forces that are placing human services in an increasingly competitive position. Makes recommendations to enhance the image of career planning and placement services and increase their usage. Concludes that by adopting a marketeer orientation,…

  3. When Placement People Are Displaced.

    ERIC Educational Resources Information Center

    Ehrlich, Marianne

    1991-01-01

    Describes the experiences and insights of five laid-off placement people who discover the trauma of job loss. Discusses grieving a job loss, the emotions involved, the challenge of finding a new job, guilt faced by survivors, and advice to colleagues. (NB)

  4. Endocoil placement after endoscopic ultrasound-guided biliary drainage may prevent a bile leak

    PubMed Central

    van der Merwe, Schalk Willem; Omoshoro-Jones, Jones; Sanyika, Charles

    2013-01-01

    AIM: To further reduce the risk of bleeding or bile leakage. METHODS: We performed endoscopic ultrasound guided biliary drainage in 6 patients in whom endoscopic retrograde cholangiopancreatography (ERCP) had failed. Biliary access of a dilated segment 2 or 3 duct was achieved from the stomach using a 19G needle. After radiologically confirming access a guide wire was placed, a transhepatic tract created using a 6 Fr cystotome followed by balloon dilation of the stricture and antegrade metallic stent placement across the malignant obstruction. This was followed by placement of an endocoil in the transhepatic tract. RESULTS: Dilated segmental ducts were observed in all patients with the linear endoscopic ultrasound scope from the proximal stomach. Transgastric biliary access was obtained using a 19G needle in all patients. Biliary drainage was achieved in all patients. Placement of an endocoil was possible in 5/6 patients. All patients responded to biliary drainage and no complications occurred. CONCLUSION: We show that placing endocoils at the time of endoscopic ultrasound guided biliary stenting is feasible and may reduce the risk of bleeding or bile leakage. PMID:23678378

  5. Abdominal anatomy in the context of port placement and trocars

    PubMed Central

    Alkatout, Ibrahim; Mettler, Liselotte; Maass, Nicolai; Noé, Günter-Karl; Elessawy, Mohamed

    2015-01-01

    Although the anatomy of the human being has not changed, technical developments in operating materials and methods demand a simultaneous development in operative management. Developments in electronic and optical technologies permit many gynecological operations to be performed laparoscopically. One fundamental distinction between any other operating method and laparoscopy is the hurdle that the initial entry, whether with a needle, cannula, or trocar, is mostly performed blind. However, there is a risk that blind entry may result in vascular or organ damage. One of the difficulties associated with entry complications is that any damage may not be immediately recognized, leading to major abdominal reparative surgery, and at worst, a temporary colostomy. Therefore, the technical and operative quality of laparoscopic surgery begins with port placement and trocars. Visual access systems are available but are not yet widely used. The aim of this review was to introduce the different port placement and trocar systems as well as their correct and professional usage in correlation with the abdominal functional anatomy. PMID:26692776

  6. 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

  7. Advanced Placement: More than a Test.

    ERIC Educational Resources Information Center

    Colwell, Richard

    1990-01-01

    Encourages music teachers to work with students interested in advanced placement (AP) music courses. Discusses the logistics and advantages of placing students in these courses. Describes the Advanced Placement Listening and Literature and the Advanced Placement Theory courses and examinations. Outlines the examination scoring method and looks at…

  8. 34 CFR 300.104 - Residential placement

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Residential placement 300.104 Section 300.104 Education... DISABILITIES State Eligibility Other Fape Requirements § 300.104 Residential placement If placement in a public or private residential program is necessary to provide special education and related services to...

  9. 34 CFR 300.104 - Residential placement

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Residential placement 300.104 Section 300.104 Education... DISABILITIES State Eligibility Other Fape Requirements § 300.104 Residential placement If placement in a public or private residential program is necessary to provide special education and related services to...

  10. Mathematics Placement at the University of Illinois

    ERIC Educational Resources Information Center

    Ahlgren Reddy, Alison; Harper, Marc

    2013-01-01

    Data from the ALEKS-based placement program at the University of Illinois is presented visually in several ways. The placement exam (an ALEKS assessment) contains precise item-specific information and the data show many interesting properties of the student populations of the placement courses, which include Precalculus, Calculus, and Business…

  11. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Child placement. 551.24 Section 551.24... Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may not permit the inmate's new born child to return to the institution except in accordance with the Bureau...

  12. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Child placement. 551.24 Section 551.24... Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may not permit the inmate's new born child to return to the institution except in accordance with the Bureau...

  13. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Child placement. 551.24 Section 551.24... Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may not permit the inmate's new born child to return to the institution except in accordance with the Bureau...

  14. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Child placement. 551.24 Section 551.24... Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may not permit the inmate's new born child to return to the institution except in accordance with the Bureau...

  15. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Child placement. 551.24 Section 551.24... Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may not permit the inmate's new born child to return to the institution except in accordance with the Bureau...

  16. Can Placement Tests Inform Instructional Decisions?

    ERIC Educational Resources Information Center

    Green, Anthony B.; Weir, Cyril J.

    2004-01-01

    Studies of placement tests are typically narrowly concerned with their validation as instruments for the efficient grouping of students. They rarely explore the assumption that placement test content can be related to classroom tasks and so inform instructional decisions. This study focuses on a trial version of the Global Placement Test (GPT), a…

  17. A Client Centered Approach to Job Placement

    ERIC Educational Resources Information Center

    Salomone, Paul R.

    1971-01-01

    A client centered placement approach for handicapped people is proposed as an alternative to the traditional selective placement method. The client centered placement is based on client responsibility and counselor direction and requires the counselor to have an unrealistic but optimistic attitude that the client will get a suitable job.…

  18. 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

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 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...

  4. [Acupoint position and manipulation of needle knife treating shoulder bi syndrome].

    PubMed

    Zhao, Li; Guo, Changqing

    2016-03-01

    With Jianyu (LI 15), Jianliao (TE 14) and Jianzhen (SI 9) for instance, the three acupoints used to treat shoulder bi syndrome by needle knife, and through traceability and researching constant structure, the acupoint position, insertion trace, manipulation and clinical significance of needle knife medicine were discussed. Accurate position is one of the characteristics of acupoints selection of needle knife medicine. As for the acupoints selection method, the mean of body surface localization is always used. The phanerous or palpable bone processes, muscles and tendons are taken as positioning marks; pressing areas where appear sour, numb, or distensible and other sensations is considered as the principle of press positioning. So acupoints position method is the combination of observation and palpation. Different insertion methods can effectively relieve the accretive bursae synovialis, tendon, joint capsule and the compressed nerve, so that shoulder bi syndrome is relieved. PMID:27344840

  5. 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.

  6. 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.

  7. Extrapleural locating method in computed tomography-guided needle biopsies of 1,106 lung lesions

    PubMed Central

    WEI, YUE-HUA; ZHOU, FU-XIANG; LI, YAN; ZHOU, YUN-FENG; ANISH, KRISHNA; XU, LI-YING; LIAO, MEI-YAN

    2015-01-01

    Transthoracic needle biopsy is considered to be safe and effective for the diagnosis of focal lung lesions. The aim of the present study was to evaluate factors affecting the accuracy and safety of automated cutting needle lung biopsy (ACNB) using a new extrapleural locating (EPL) method. Computed tomography (CT)-guided needle biopsies were performed on 1,065 patients between March 2005 and May 2012 using the EPL method. The locating needle remained in the chest following extrapleural positioning, while the radiologist confirmed the puncture angle and distance between the locating needle and lesion. The biopsy instrument was advanced into the lung, and the core needle was subsequently fired into the lesion based on the direction indicated by the locating needle. Univariate and multivariate regression analyses were used to evaluate the diagnostic accuracy and safety of the procedure. The sensitivity, specificity, positive predictive value and negative predictive value of the extrapleural method were 91.9, 100, 100 and 82.9%, respectively, and the overall diagnostic accuracy was 94.2%. Significant risk factors affecting accuracy were younger age, atelectasis, hemoptysis and lesion depth (P<0.03). Multivariate logistic regression analysis revealed that the risk of malignant lesions receiving a false-negative diagnosis decreased for each additional year of subject age [odds ratio (OR), 0.97; P=0.027] and increased with each millimeter increase in lesion depth (OR, 1.03; P=0.008). Among the 1,106 lesions biopsied, 207 were associated with pneumothorax, 251 with hemorrhage and 58 with hemoptysis. Multivariate analysis revealed that lesion size and emphysema affected pneumothorax incidence, while age, lesion location and depth and emphysema significantly affected hemorrhage incidence (P<0.05). In conclusion, low-dose, CT-guided ACNB with the EPL method provides a safe and accurate diagnosis. PMID:26640541

  8. 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

  9. Family ties and child placement.

    PubMed

    Colón, F

    1978-09-01

    The fundamental premise of this paper is the primacy of the child's experience of biological-familial continuity in establishing his sense of self and personal significance. This paper examines the effects of current child placement practices on the child's ties to his biological, foster, and adoptive families. It explores alternative practices that would take into account biological-familial continuity. Comment is invited. PMID:744218

  10. Combination of needle aspiration and core needle biopsy: A new technique of stereotactic biopsy

    PubMed Central

    Wani, Abrar Ahad; Wani, M. Afzal; Ramzan, Altaf U.; Nizami, Furqan A.; Malik, Nayil K.; Shafiq, S.; Ahmad, Rais; Kumar, Ashish; Lone, Iqbal; Makhdoomi, Rumana

    2016-01-01

    Aim: The study aims at describing the results of using a new technique to acquire the tissue sample in stereotactic biopsy of brain lesions. Materials and Methods: The study was performed in 19 patients over a period of 5 years in which we used the new technique, i.e., Abrar and Afzal technique (AT) of obtaining tissue biopsy. It is a combination of core tissue biopsy and needle aspiration techniques. The technique was devised to acquire greater amount of tissue for pathologic study. Results: While we could give pathologic diagnosis in 18 patients out of 19 (94.7%), in one patient, the tissue sample revealed only inflammatory cells and definitive diagnosis could not be reached. There was no significant morbidity or any mortality in the series. Conclusion: Abrar and Afzal technique is a reasonably accurate technique of acquiring larger tissue sample in stereotactic brain biopsy without any additional risks. It can be done with little modification of the conventional equipment available with the stereotactic system. PMID:27057212

  11. Endovascular management of IVC syndrome after IVC filter placement.

    PubMed

    Marmagkiolis, Konstantinos; Lendel, Vasili; Cilingiroglu, Mehmet

    2015-09-01

    Approximately 60,000-100,000 Americans die from deep venous thrombosis or pulmonary embolism annually, while the overall estimate of individuals affected is 30,000-600,000. Inferior vena cava (IVC) filter placement has emerged as a break-through endovascular technique which has gained increasing acceptance and has probably saved thousands of lives by preventing fatal thromboembolic events. However, in the absence of a national IVC filter registry an accurate estimate of device complications is currently unavailable. We present a case of symptomatic IVC syndrome due to IVC interruption in a patient with a non-retrievable IVC filter. This patient was initially managed with balloon angioplasty and mechanical thrombectomy with suboptimal results and subsequently with stent placement through the IVC filter. PMID:26298105

  12. 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

  13. Initial Decomposition and Humification Dynamics of Ponderosa Pine Fine Roots and Needles

    NASA Astrophysics Data System (ADS)

    Bird, J. A.; Torn, M. S.

    2002-12-01

    To understand the influence of litter chemistry and microclimate on the long-term stabilization of plant inputs, it is essential to better understand biological and chemical regulation of the conversion of litter to stable soil organic matter (SOM). We present first-year results from a 3-year field study examining the fate of 13C- and 15N- labeled Pinus ponderosa in an 80-year-old conifer forest in the Sierra Nevada, CA on an Ultic Haploxeralf. Our objectives are to assess the effects of litter type (fine roots vs. needles) and substrate placement depth (O vs. A horizon) on rates of C and N mineralization, immobilization into microbial biomass and specific microbial groups, and stabilization into SOM fractions. Data will be presented on recovery of 13C and 15N in soil microbial, mineral and SOM fractions after 152 d and C respiration over the initial 300 d. In situ litter decomposition, as estimated by 13C respiration, of needles exceeded that of roots by 270% at 61 d, by 140% at 152 d and was similar for the two substrates at 221 d. Comparing the effect of soil depth, pine needles had greater 13C respiration in the O horizon than in the A horizon through 152 d, while the rate of fine root decay was not significantly different between soil depths through 221 d.

  14. Model-based assessment of probe placement criteria in cancer therapy using RF ablation

    NASA Astrophysics Data System (ADS)

    Tanotogono, E. W.; Akasum, G. F.; Suprijanto; Sudirham, J. J.

    2016-03-01

    Radiofrequency ablation has been developed as a minimally-invasive method for cancer therapy. Nevertheless, the unfeasibility of direct observation during ablation process sometimes becomes a challenge for practitioners, particularly those constrained by the absence of a proper monitoring system. Thus, aiming to develop a prudent cancer therapy planning, this research develops a 3D model that enable practitioners to predict the tissue damage resulted by a simulated ablation before a real ablation is executed. The model, developed using finite element method, is made to mimic real human liver tissue by simulating its physical properties as temperature-dependent functions. Three probe placement cases, representing three different approaches, are analysed to study the effect of probe placement configuration on tissue damage formed during a time-dependent ablation process. The three placement cases are surface-perpendicular placement, misaligned placement, and relatively accurate placement. It can be concluded that the accuracy of a probe placement configuration can be assessed by quantifying two major parameters: average tissue damage in the target domain and accumulated damage resulted in complementary tissue domain. Optimum ablation duration can also be determined by considering those parameters.

  15. 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

  16. 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.

  17. 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.

  18. Acadian flycatcher nest placement: Does placement influence reproductive success?

    USGS Publications Warehouse

    Wilson, R.R.; Cooper, R.J.

    1998-01-01

    We located 511 Acadian Flycatcher (Empidonax virescens) nests in bottomland hardwood forest of eastern Arkansas. Microhabitat characteristics were measured and their relationship with nest success evaluated. Fifty-two percent of all nesting attempts resulted in predation. Attributes of nest placement were similar between successful and unsuccessful nests, although successful nests were placed higher. Similarly, nonparasitized nests were typically higher than parasitized nests. Nests initiated late in the breeding season were placed in larger trees with higher canopy bases resulting in increased vegetation around the nest. Fifteen different tree species were used for nesting. Acadian Flycatchers chose nest trees in a nonrandom fashion, selecting Nuttall oak (Quercus nuttallii) and possumhaw (Ilex decidua) in greater proportions than their availability. However, there was no relationship between tree species used for nesting and nest success. Nest height was positively correlated with concealment at the nest site, supporting the predator-avoidance theory. No other attribute of nest placement differentiated successful nest sites, suggesting that nest predation is likely a function of random events in space and time.

  19. Peripheral Stent Placement in Hemodialysis Grafts

    SciTech Connect

    Kariya, Shuji Tanigawa, Noboru; Kojima, Hiroyuki; Komemushi, Atsushi; Shomura, Yuzo; Shiraishi, Tomokuni; Kawanaka, Toshiaki; Sawada, Satoshi

    2009-09-15

    The purpose of the present study was to evaluate the clinical outcome of peripheral stent placement after failed balloon angioplasty in patients with grafts who are on hemodialysis. We examined 30 Wallstents that were placed in 26 patients because balloon angioplasty failed or early restenosis (<3 months) occurred within 3 months. We retrospectively reviewed 267 consecutive balloon angioplasties performed in 71 patients with graft access between August 2000 and March 2007. Stent placements accounted for 30 (11.2%) of the 267 balloon angioplasties. The clinical success rate of stent placement was 93.3% (28 of 30 stent placements). The 3-, 6-, and 12-month primary patency rates were 73.3%, 39.3%, and 17.7%, respectively. The 1-, 2-, and 3-year secondary patency rates were 90.2%, 83.8%, and 83.8%, respectively. Primary patency was significantly prolonged by stent placement after early restenosis compared with previous balloon angioplasty alone (P = 0.0059). Primary patency after stent placement was significantly lower than after successful balloon angioplasty without indications for stent placement (P = 0.0279). Secondary patency rates did not significantly differ between stent placement and balloon angioplasty alone. The mean number of reinterventions required to maintain secondary patency after stent placement was significantly larger than that after balloon angioplasty alone (Mann-Whitney U test, P = 0.0419). We concluded that peripheral stent placement for graft access is effective for salvaging vascular access after failed balloon angioplasty and for prolonging patency in early restenosis after balloon angioplasty. However, reinterventions are required to maintain secondary patency after stent placement. Furthermore, peripheral stent placement for graft access cannot achieve the same primary patency as balloon angioplasty alone.

  20. Grading More Accurately

    ERIC Educational Resources Information Center

    Rom, Mark Carl

    2011-01-01

    Grades matter. College grading systems, however, are often ad hoc and prone to mistakes. This essay focuses on one factor that contributes to high-quality grading systems: grading accuracy (or "efficiency"). I proceed in several steps. First, I discuss the elements of "efficient" (i.e., accurate) grading. Next, I present analytical results…

  1. Product placement of computer games in cyberspace.

    PubMed

    Yang, Heng-Li; Wang, Cheng-Shu

    2008-08-01

    Computer games are considered an emerging media and are even regarded as an advertising channel. By a three-phase experiment, this study investigated the advertising effectiveness of computer games for different product placement forms, product types, and their combinations. As the statistical results revealed, computer games are appropriate for placement advertising. Additionally, different product types and placement forms produced different advertising effectiveness. Optimum combinations of product types and placement forms existed. An advertisement design model is proposed for use in game design environments. Some suggestions are given for advertisers and game companies respectively. PMID:18721087

  2. Automated fiber placement: Evolution and current demonstrations

    NASA Technical Reports Server (NTRS)

    Grant, Carroll G.; Benson, Vernon M.

    1993-01-01

    The automated fiber placement process has been in development at Hercules since 1980. Fiber placement is being developed specifically for aircraft and other high performance structural applications. Several major milestones have been achieved during process development. These milestones are discussed in this paper. The automated fiber placement process is currently being demonstrated on the NASA ACT program. All demonstration projects to date have focused on fiber placement of transport aircraft fuselage structures. Hercules has worked closely with Boeing and Douglas on these demonstration projects. This paper gives a description of demonstration projects and results achieved.

  3. Adaptable Deployable Entry and Placement Technology (ADEPT)

    NASA Video Gallery

    The Adaptable, Deployable Entry Placement Technology (ADEPT) Project will test and demonstrate a deployable aeroshell concept as a viable thermal protection system for entry, descent, and landing o...

  4. Opening up placement opportunities for students.

    PubMed

    Hill, Phillipa; Bullpitt, Samantha; Dean, Sharon; O'Flanagan, Sheryl; Fishburn, Nicky

    Student nurses need a variety of high-quality practice placements to prepare them for qualification yet, in reality, this can be difficult to achieve. A practice placement allocation model has enabled one university and its partner healthcare organisations to shift from a traditional, process-led system to a robust, proactive, student-focused approach. The model is based on partnership concepts including advance planning of student placements and clear lines of communication. It has resulted in 100% of first-year students taking part in a new fundamentals of care placement and received positive feedback from students and mentors. PMID:26012012

  5. 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

  6. 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

  7. ["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

  8. EUS-guided drainage and stent placement for postoperative intra-abdominal and pelvic fluid collections in oncological surgery

    PubMed Central

    Vilar-Cao, Zenaida; Sardina-Ferreiro, Raquel

    2012-01-01

    Objectives: The objective of this study was to evaluate the role and benefits of endoscopic ultrasonography (EUS) in the management of postoperative intra-abdominal fluid collections after attempted curative surgery for abdominal cancer. Methods: The authors retrospectively analysed the Endobase from 1 July 2007 to 30 January 2011 for patients with a postoperative intra-abdominal fluid collection who had undergone EUS-guided drainage and the placement of a stent. The data analysed included the demographics, type of surgery and clinical indications of each patient as well as their clinical and radiological findings. Results: Six patients (three men and three women; mean age, 61.8 years [range, 38–78 years]) with intra-abdominal and pelvic fluid collections after abdominal surgery for cancer had undergone EUS-guided internal drainage. All procedures had been performed using linear EUS guidance and 8-Fr stent drainage catheters (‘one step device’, Giovannini, NWOA system Needle-Wire, Cook). The collection types included perigastric abscess (n = 3), perigastric hematoma and rectal hematoma (n = 1), perirectal biloma (n = 1), and perirectal abscess (n = 1). Patients had undergone the following types of surgery: lower-anterior rectal resection (n = 2), Whipple’s duodenopancreatectomy type (n = 1), total gastrectomy (n = 1), splenectomy (n = 1), and distal pancreatectomy (n = 1). The number of stents inserted for each collection was one (five patients) and two (one patient). Conclusions: EUS-guided drainage and stenting provide another option for the management of postoperative collections. It allows access to areas that are difficult to reach with the CT-guided approach and it can be performed accurately, efficiently and safely. In addition to this, the internal nature of the drainage offers patients more comfort. PMID:22423258

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

    PubMed

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

    2016-01-01

    Intrathecal catheter devices using a catheter-over-needle design and softer flexible material have been introduced to clinical practice with the aim of reducing some of the complications such as postdural puncture headaches and paresthesias seen with previous versions of intrathecal catheters. We present a case series of 5 cesarean deliveries using the Wiley Spinal intrathecal system (Epimed, Johnstown, New York), which was recently approved by the US Food and Drug Administration. The intrathecal catheter system consists of a flexible 23-gauge intrathecal cannula over a 27-gauge pencil-point spinal needle. The placement of the intrathecal catheter was successful in all 5 cases; however, paresthesias in 3 cases and postdural puncture headaches in 2 cases complicated the placement and use of the device. Although the unique catheter-over-needle design facilitates the use of smaller-gauge spinal needles for dural puncture and larger-gauge catheters for medication administration, this case series using the Wiley Spinal suggests that paresthesias and postdural puncture headaches may still limit its widespread utilization. Future studies are needed to determine the true incidence of complications and to determine the role of continuous spinal anesthesia in the obstetric population. PMID:26909488

  10. 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.

  11. 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.

  12. 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

  13. Gel placement in fractured systems

    SciTech Connect

    Seright, R.S.

    1995-11-01

    This paper examines several factors that can have an important effect on gel placement in fractured systems, including gelant viscosity, degree of gelation, and gravity. For an effective gel treatment, the conductivity of the fracture must be reduced and a viable flow path must remain open between the wellbore and mobile oil in the reservoir. During placement, the gelant that``leaks off`` from the fracture into the rock plays an important role in determining how well a gel treatment will reduce channeling. For a given volume of gelant injected the distance of gelant leakoff is greater for a viscous gelant than for a low-viscosity gelant. In one method to minimize gelant leakoff, sufficient gelation is designed to occur before the gelant leaves the wellbore. The authors investigated this approach in numerous experiments with both fractured and unfractured cores. They studied Cr(III)/acetate/hydrolyzed polyacrylamide (HPAM), resorcinol/formaldehyde, Cr(III)/xanthan, aluminum/citrate/HPAM, and other gelants and gels with various delay times between gelant preparation and injection. Their results suggest both hope and caution concerning the injection of gels into fractured systems.

  14. Guidance of Block Needle Insertion by Electrical Nerve Stimulation: A Pilot Study of the Resulting Distribution of Injected Solution in Dogs

    PubMed Central

    Rigaud, Marcel; Filip, Patrick; Lirk, Philipp; Fuchs, Andreas; Gemes, Geza; Hogan, Quinn

    2009-01-01

    Background Little is known regarding the final needle tip location when various intensities of nerve stimulation are used to guide block needle insertion. Therefore, in control and hyperglycemic dogs, the authors examined whether lower-intensity stimulation results in injection closer to the sciatic nerve than higher-threshold stimulation. Methods During anesthesia, the sciatic nerve was approached with an insulated nerve block needle emitting either 1 mA (high-current group, n = 9) or 0.5 mA (low-current group, n = 9 in control dogs and n = 6 in hyperglycemic dogs). After positioning to obtain a distal motor response, the lowest current producing a response was identified, and ink (0.5 ml) was injected. Frozen sections of the tissue revealed whether the ink was in contact with the epineurium of the nerve, distant to it, or within it. Results In control dogs, the patterns of distribution using high-threshold (final current 0.99 ± 0.03 mA, mean ± SD) and low-threshold (final current 0.33 ± 0.08 mA) stimulation equally showed ink that was in contact with the epineurium or distant to it. One needle placement in the high-threshold group resulted in intraneural injection. In hyperglycemic dogs, all needle insertions used a low-threshold technique (n = 6, final threshold 0.35 ± 0.08 mA), and all resulted in intraneural injections. Conclusions In normal dogs, current stimulation levels in the range of 0.33–1.0 mA result in needle placement comparably close to the sciatic nerve but do not correlate with distance from the target nerve. In this experimental design, low-threshold electrical stimulation does not offer satisfactory protection against intraneural injection in the presence of hyperglycemia. PMID:18719445

  15. Endovascular Placement of an Extraluminal Femoropopliteal Bypass Graft in Human Cadavers

    SciTech Connect

    Maynar, Manuel; Llorens, Rafael; Lopez-Sanchez, Carmen; Garcia-Martinez, Virginio; Qian Zhong; Lopera, Jorge; Castaneda, Wilfrido R.

    2005-04-15

    Purpose. A method to create an extraluminal femoropopliteal bypass graft using endovascular techniques was evaluated in situ on cadaver extremities in an attempt to develop a minimally invasive alternative technique for the management of infrainguinal occlusive arterial disease. Methods. The endovascular placement of an extraluminal femoropopliteal bypass graft was undertaken in 5 cadaver legs. Following percutaneous access to the popliteal artery (PA) or common femoral artery (CFA), a Rosch-Uchida needle was used to perforate the vascular wall, followed by the creation of an extraluminal tract using a looped wire and catheter. Once the desired level was reached the needle was again used to perforate the vascular wall of the proximal superficial femoral artery (SFA) or PA depending on the access used. Self-expanding expanded polytetrafluoroethylene (ePTFE) stent-grafts were then deployed to establish the extraluminal femoropopliteal bypass connecting the two arterial puncture sites. Following dilatation of the stent-graft, angiography was performed to assess the endoprostheses and to look for contrast leaks. Results. Technical success was achieved in all 5 legs. Procedure time varied from 15 to 30 min. The angiographic studies performed immediately after completion of the bypass procedure showed patency of the grafts with no evidence of kinking or leakage in any of the cases. Conclusion. This study has proved that the endovascular placement of an extraluminal femoropopliteal bypass graft in human cadaver legs using endovascular techniques under fluoroscopic control is technically feasible.

  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. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  3. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  4. Changing attitudes toward needle biopsies of breast cancer in Shanghai: experience and current status over the past 8 years

    PubMed Central

    Hao, Shuang; Liu, Zhe-Bin; Ling, Hong; Chen, Jia-Jian; Shen, Ju-Ping; Yang, Wen-Tao; Shao, Zhi-Min

    2015-01-01

    Diagnostic patterns in breast cancer have greatly changed over the past few decades, and core needle biopsy (CNB) has become a reliable procedure for detecting breast cancer without invasive surgery. To estimate the changing diagnostic patterns of breast cancer in urban Shanghai, 11,947 women with breast lesions detected by preoperative needle biopsy between January 1995 and December 2012 were selected from the Shanghai Cancer Data base, which integrates information from approximately 50% of breast cancer patients in Shanghai. The CNB procedure uses an automated prone unit, biopsy gun, and 14-gauge needles under freehand or ultrasound guidance and was performed by experienced radiologists and surgeons specializing in needle biopsies. Diagnosis and classification for each patient were independently evaluated by pathologists. Over the indicated 8-year period, biopsy type consisted of 11,947 ultrasound-guided core needle biopsies (UCNBs), 2,015 ultrasound-guided vacuum-assisted biopsies (UVABs), and 654 stereotactic X-ray-guided vacuum-assisted biopsies (XVABs). For all the 11,947 women included in this study, image-guided needle biopsy was the initial diagnostic procedure. Approximately 81.0% of biopsied samples were histopathologically determined to be malignant lesions, 5.5% were determined to be high-risk lesions, and 13.5% were determined to be benign lesions. The number of patients choosing UCNB increased at the greatest rate, and UCNB has become a standard procedure for histodiagnosis because it is inexpensive, convenient, and accurate. The overall false-negative rate of CNB was 1.7%, and the specific false-negative rates for UCNB, UVAB, and XVAB, were 1.7%, 0%, and 0%, respectively. This study suggests that the use of preoperative needle biopsy as the initial breast cancer diagnostic procedure is acceptable in urban Shanghai. Preoperative needle biopsy is now a standard procedure in the Shanghai Cancer Center because it may reduce the number of surgeries

  5. 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…

  6. 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…

  7. 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

  8. 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. ...

  9. 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

  10. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  11. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  12. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  13. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  14. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  15. Exploring Continuous Clinical Placement for Undergraduate Students

    ERIC Educational Resources Information Center

    McKenna, Lisa G.; Wray, Natalie; McCall, Louise

    2009-01-01

    Clinical placements are integral to health professional preparatory courses. These placements allow for the application of classroom-based learning into real patient care situations. In doing so, they provide opportunities for applying theoretical knowledge into practice contexts, skills development and socialisation into the chosen profession.…

  16. Advanced Placement Courses and American Indian Performance

    ERIC Educational Resources Information Center

    Moore, George; Slate, John R.

    2010-01-01

    Enrollment in Advanced Placement (AP) courses and performance on Advanced Placement examinations for American Indians in the U.S. for 2007 was analyzed. Scores on AP examinations, overall and then for five AP courses, were compared to the AP examination scores of White students. In every case, American Indians had AP examination scores that were…

  17. Film Processing Module for Automated Fiber Placement

    NASA Technical Reports Server (NTRS)

    Hulcher, A. Bruce

    2004-01-01

    This viewgraph presentation describes fiber placement technology which was originally developed by Marshall Space Flight Center (MSFC) for the fabrication of fiber composite propellant tanks. The presentation includes an image of the MSFC Fiber Placement Machine, which is a prototype test bed, and images of some of the machine's parts. Some possible applications for the machines are listed.

  18. PASS--Placement/Advisement for Student Success.

    ERIC Educational Resources Information Center

    Shreve, Chuck; Wildie, Avace

    In 1985-86, Northern Michigan College (NMC) used funds received from the United States Department of Education to develop a system of assessment, advisement, and placement--Placement/Advisement for Student Success (PASS), an integrated system designed to improve student retention. PASS currently consists of three components: summer orientation,…

  19. Private Placement Debt Financing for Public Entities

    ERIC Educational Resources Information Center

    Holman, Lance S.

    2010-01-01

    Private placement financing is a debt or capital lease obligation arranged between a municipality or a 501(c) (3) not-for-profit organization and a single sophisticated institutional investor. The investor can be a bank, insurance company, finance company, hedge fund, or high-net worth individual. Private placement financing is similar to…

  20. Preceptor Handbook: Rural Clinical Nurse Placement Center.

    ERIC Educational Resources Information Center

    Stuart-Siddall, Sandra; Haberlin, Jean

    This handbook provides Rural Clinical Nurse Placement Program (RCNP) preceptors with a program overview and practical suggestions to apply during student placement. An introductory section describes how the program addresses the maldistribution of nurses by raising awareness about the rural experience, adding a needed perspective to the urban bias…

  1. Understanding Successful Sandwich Placements: A Bourdieusian Approach

    ERIC Educational Resources Information Center

    Clark, Martyn; Zukas, Miriam

    2016-01-01

    Sandwich placements and other integrated work and study schemes are increasingly advocated as a key means by which universities can promote students' employability. However, there is little understanding of how successful placements work in terms of facilitating learning and development. Drawing on three longitudinal case studies of students who…

  2. Preparing ESP Learners for Workplace Placement

    ERIC Educational Resources Information Center

    Wood, David

    2009-01-01

    Engineering students in North American universities often participate in cooperative education placements in workplaces as part of the requirements for their degrees and professional certification. Students for whom English is an L2 often experience difficulties in these placements due to the fact that while their academic language ability may be…

  3. Implementation of Job Placement Services Guidelines.

    ERIC Educational Resources Information Center

    McGillicuddy (Shirley) & Associates, Sierra Madre, CA.

    The Implementation of Job Placement Services Guidelines Project was designed to strengthen placement programs and services for California community college vocational students, and for all students needing part-time employment to realize their educational goals. The project was designed to test the validity and relevance of quality indicators…

  4. Job Placement and the School Counselor.

    ERIC Educational Resources Information Center

    Goeke, John D.; Salomone, Paul R.

    1979-01-01

    The trend toward career education in the schools and its implications suggest the addition of job placement, especially client-centered placement, as part of the school counselor's responsibility. Planning for its eventual inclusion can only increase a counselor's ability to adapt in an ever-changing system of transient educational priorities.…

  5. 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…

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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

  2. Birth placement and child health.

    PubMed

    Fergusson, D M; Horwood, J; Shannon, F T

    1981-07-22

    The standards of health and health care for a sample of 1265 Christchurch children during the period birth to three years were examined. There was a systematic tendency for levels of health care and morbidity to vary with the child's birth placement: in general adopted children had the best standard of health care and the lowest rates of morbidity; children who entered single parent families at birth had the poorest standards of health care and the highest rates of morbidity. Statistical control for family social background including maternal age, education, ethnic status, family size and changes of residence tended to reduce the size of the observed differences. However, even when the results were controlled for these factors children in single parent families still has depressed levels of preventive health care and higher rates of hospital admission. Possible explanations of the differences are discussed. PMID:6944632

  3. Using more healthcare areas for placements.

    PubMed

    Sherratt, Lou; Whitehead, Bill; Young, Alwyn; Collins, Guy; Brundrett, Heather

    The need for private, voluntary and independent placements in nursing programmes has become more important in recent years due to changes in where health services are delivered. These placements can be used effectively within nursing programmes to show students the realities of healthcare, and to challenge myths and attitudes. Dedicated time and resources need to be provided to discover and maintain these placements, and to ensure appropriate, high-quality learning opportunities. This article presents the findings of a national Higher Education Academy workshop, held at the University of Derby in November 2012. It explores three key issues discussed at the workshop: current practice and opportunities for learning; myths, attitudes and solutions; and maintaining the quality of placements. The use of PVI placements is seen as valuable and a set of recommendations are provided to assist in their use. PMID:23905296

  4. Genetic Algorithm Approaches for Actuator Placement

    NASA Technical Reports Server (NTRS)

    Crossley, William A.

    2000-01-01

    This research investigated genetic algorithm approaches for smart actuator placement to provide aircraft maneuverability without requiring hinged flaps or other control surfaces. The effort supported goals of the Multidisciplinary Design Optimization focus efforts in NASA's Aircraft au program. This work helped to properly identify various aspects of the genetic algorithm operators and parameters that allow for placement of discrete control actuators/effectors. An improved problem definition, including better definition of the objective function and constraints, resulted from this research effort. The work conducted for this research used a geometrically simple wing model; however, an increasing number of potential actuator placement locations were incorporated to illustrate the ability of the GA to determine promising actuator placement arrangements. This effort's major result is a useful genetic algorithm-based approach to assist in the discrete actuator/effector placement problem.

  5. [Ultrasound-guided peripheral regional anesthesia : placement and dosage of local anesthetics].

    PubMed

    Gorsewski, G; Dinse-Lambracht, A; Tugtekin, I; Gauss, A

    2012-08-01

    Ever since the use of ultrasound guidance in regional anesthesia became more and more popular in recent years, it seemed obvious that so-called intraneural puncture and injection of local anesthetics was much more common than previously assumed. However, neurologic damage was not seen very often. The ultrasound-guided imaging of the nerves showed that intraneural injection has to be seen as an overall term. This term must be characterized in more detail in accordance with nerve anatomy and morphology. Various studies demonstrated that if intraneural puncture occured the needle usually took a path away from the fascicles (intraneural perifascicular), while intraneural transfascicular puncture seemed relatively rare and intraneural intrafascicular placement of the needle even more uncommon. As long as the needle is placed intraneurally but in an extrafascicular fashion a safe injection and the absence of neurologic damage can be assumed. However, if nerve fascicles are affected neurologic dysfunction can occur. In studies investigating the minimal effective local anesthetic volume needed for successful nerve block, a relevant reduction of injected volume was still achieved by intentionally applying the local anesthetic circumferentially around the outermost nerve layer rather than injecting it into neural structures. As an intraneural -intrafascicular injection carries the risk of nerve injury associated with a decrease in quality of life, the potential of ultrasound guidance in regional anesthesia should be considered. Circumferential administration of local anesthetic rather than creating a single point injection appears to be advantageous. PMID:22790475

  6. 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

  7. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing.

    PubMed

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    BACKGROUND The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. MATERIAL AND METHODS Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. RESULTS With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. CONCLUSIONS A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  8. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing

    PubMed Central

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    Background The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. Material/Methods Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. Results With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. Conclusions A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  9. [Morphology determination of ionization region in multi-needle-to-plate negative corona discharge].

    PubMed

    Su, Peng-Hao; Zhu, Yi-Min; Chen, Hai-Feng

    2007-11-01

    Based on the former work on the current-voltage characteristics of a multi-needle-to-plate negative corona discharge at atmospheric pressure, the present work uses the method of OES (optical emission spectrum) for measuring N2 emission spectrum, and the morphology determination of the ionization region has been investigated. According to the distribution of N2 second positive band's intensity I(SPB), the highest of all bands, the outline of the ionization region was drawn fairly accurately. The relationship between I(SPB) and discharge current I can be obtained through the volume integral of the I(SPB). The experimental results show that the size of the ionization region enhances with the rise of the applied voltage U, and the electron avalanche begins at about 1 mm off the tips of needle electrode and multiplies only in the range of several millimeters, indicating that, the range of the ionization region is at the magnitude of mm. The electron avalanche along the axis of the needle develops farther than that along the radial direction of needle, and the shape of the ionization region looks like a bullet. The integral of I(SPB) is second-order linear to I, with a very second order coefficient, meaning that the main excited substance is N2. Energetic electrons mainly exist in ionization region while ions are the main charged particles to form discharge current in the transfer region. PMID:18260386

  10. Relationship between levels of polycyclic aromatic hydrocarbons in pine needles and socio-geographic parameters.

    PubMed

    Fernández-Varela, Raquel; Ratola, Nuno; Alves, Arminda; Amigo, José Manuel

    2015-06-01

    The ability of pine needles to capture polycyclic aromatic hydrocarbons (PAHs) from the surrounding air is well known. In this work the current knowledge of this affinity will be enhanced, investigating the plausible links between the concentrations of PAHs found in pine needles collected in different sites in Portugal, and several socio-geographic variables with environmental relevance. Canonical correlation analysis (CCA) has proven to be a suitable and innovative technique to look for relationships within environmental datasets. In the current work, CCA will simultaneously include chemical information (concentration of PAHs found in pine needles) and socio-geographic information associated to the sampling areas. In order to be more robust in these conclusions, Pinus pinea and Pinus pinaster species were considered separately, allowing an accurate direct comparison between them. The information concerning the different seasons and land occupation was also taken into account. Our results demonstrate how CCA can be a useful tool in environmental impact assessment, and highlight the importance of pine needles as trustful biomonitors of the influence of socio-geographic parameters on the levels of PAHs in a given area. PMID:25794966

  11. Enhanced leukemia cell detection using a novel magnetic needle and nanoparticles

    PubMed Central

    Jaetao, Jason E.; Butler, Kimberly S.; Adolphi, Natalie L.; Lovato, Debbie M.; Bryant, Howard C.; Rabinowitz, Ian; Winter, Stuart S.; Tessier, Trace E.; Hathaway, Helen J.; Bergemann, Christian; Flynn, Edward R.; Larson, Richard S.

    2009-01-01

    Acute leukemia is a hematopoietic malignancy for which the accurate measurement of minimal residual disease is critical to determining prognosis and treatment. While bone marrow aspiration and light microscopy remain the current standard of care for detecting residual disease, these approaches cannot reliably discriminate less than 5% lymphoblast cells. To improve the detection of leukemia cells in the marrow, we developed a novel apparatus that employs antibodies conjugated to superparamagnetic iron oxide nanoparticles (SPIONs) and directed against the acute leukemia antigen CD34, coupled with a “magnetic needle” biopsy. Leukemia cell lines expressing high or minimal CD34 were incubated with anti-CD34-conjugated SPIONs. Three separate approaches including microscopy, Superconducting Quantum Interference Device (SQUID) magnetometry, and in vitro magnetic needle extraction were then employed to assess cell sampling. We found that CD34-conjugated nanoparticles preferentially bind high CD34-expressing cell lines. Furthermore, the magnetic needle enabled identification of both cell line and patient leukemia cells diluted into normal blood at concentrations below those normally found in remission marrow samples. Finally, the magnetic needle enhanced the percentage of lymphoblasts detectable by light microscopy by ten-fold in samples of fresh bone marrow aspirate approximating minimal residual disease. These data suggest that bone marrow biopsy using antigen-targeted magnetic nanoparticles and a magnetic needle for the evaluation of minimal residual disease in CD34-positive acute leukemias can significantly enhance sensitivity compared to the current standard of care. PMID:19808954

  12. 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

  13. Innovative approaches to neuraxial blockade in children: The introduction of epidural nerve root stimulation and ultrasound guidance for epidural catheter placement

    PubMed Central

    Tsui, Ban CH

    2006-01-01

    Continuous epidural blockade remains the cornerstone of pediatric regional anesthesia. However, the risk of catastrophic trauma to the spinal cord when inserting direct thoracic and high lumbar epidural needles in anesthetized or heavily sedated pediatric patients is a concern. To reduce this risk, research has focused on low lumbar or caudal blocks (ie, avoiding the spinal cord) and threading catheters from distal puncture sites in a cephalad direction. However, with conventional epidural techniques, including loss-of-resistance for localization of the needle, optimal catheter tip placement is difficult to assess because considerable distances are required during threading. Novel approaches include electrical epidural stimulation for physiological confirmation and segmental localization of epidural catheters, and ultrasound guidance for assessing related neuroanatomy and real-time observation of the needle puncture and, potentially, catheter advancement. The present article provides a brief and focused review of these two advances, and outlines recent clinical experiences relevant to pediatric epidural anesthesia. PMID:16960634

  14. 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.

  15. 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.

  16. 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.

  17. Effectiveness and limitations of core needle biopsy in the diagnosis of thyroid nodules: review of current literature.

    PubMed

    Yoon, Jung Hyun; Kim, Eun-Kyung; Kwak, Jin Young; Moon, Hee Jung

    2015-05-01

    Fine needle aspiration (FNA) is currently accepted as an easy, safe, and reliable tool for the diagnosis of thyroid nodules. Nonetheless, a proportion of FNA samples are categorized into non-diagnostic or indeterminate cytology, which frustrates both the clinician and patient. To overcome this limitation of FNA, core needle biopsy (CNB) of the thyroid has been proposed as an additional diagnostic method for more accurate and decisive diagnosis for thyroid nodules of concern. In this review, we focus on the effectiveness and limitations of CNB, and what factors should be considered when CNB is utilized in the diagnosis of thyroid nodules. PMID:26018514

  18. 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

  19. 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

  20. 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.

  1. Accurate measurement of time

    NASA Astrophysics Data System (ADS)

    Itano, Wayne M.; Ramsey, Norman F.

    1993-07-01

    The paper discusses current methods for accurate measurements of time by conventional atomic clocks, with particular attention given to the principles of operation of atomic-beam frequency standards, atomic hydrogen masers, and atomic fountain and to the potential use of strings of trapped mercury ions as a time device more stable than conventional atomic clocks. The areas of application of the ultraprecise and ultrastable time-measuring devices that tax the capacity of modern atomic clocks include radio astronomy and tests of relativity. The paper also discusses practical applications of ultraprecise clocks, such as navigation of space vehicles and pinpointing the exact position of ships and other objects on earth using the GPS.

  2. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  3. 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

  4. [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

  5. Setting standards for high-quality placements.

    PubMed

    Aitkenhead, Susan; Farran, Sean; Bateman, Ian

    As part of a project undertaken by a local education and training board, a wide range of stakeholders across South London were asked what makes a high-quality practice placement for student nurses, and how that quality could be effectively measured. This article outlines the drafting and testing of a set of quality standards in a mix of provider settings. Although further refinement is required, the standards enabled placement sites to question themselves about their own education and training processes, strengthened their partnership with the training and education board and facilitated the assurance that student nurses receive safe, effective and compassionate preparation when they are on placement. PMID:26434190

  6. Advanced fiber placement of composite fuselage structures

    NASA Technical Reports Server (NTRS)

    Anderson, Robert L.; Grant, Carroll G.

    1991-01-01

    The Hercules/NASA Advanced Composite Technology (ACT) program will demonstrate the low cost potential of the automated fiber placement process. The Hercules fiber placement machine was developed for cost effective production of composite aircraft structures. The process uses a low cost prepreg tow material form and achieves equivalent laminate properties to structures fabricated with prepreg tape layup. Fiber placement demonstrations planned for the Hercules/NASA program include fabrication of stiffened test panels which represent crown, keel, and window belt segments of a typical transport aircraft fuselage.

  7. Accurate placement of substrate RNA by Gar1 in H/ACA RNA-guided pseudouridylation

    PubMed Central

    Wang, Peng; Yang, Lijiang; Gao, Yi Qin; Zhao, Xin Sheng

    2015-01-01

    H/ACA RNA-guided ribonucleoprotein particle (RNP), the most complicated RNA pseudouridylase so far known, uses H/ACA guide RNA for substrate capture and four proteins (Cbf5, Nop10, L7Ae and Gar1) for pseudouridylation. Although it was shown that Gar1 not only facilitates the product release, but also enhances the catalytic activity, the chemical role that Gar1 plays in this complicated machinery is largely unknown. Kinetics measurement on Pyrococcus furiosus RNPs at different temperatures making use of fluorescence anisotropy showed that Gar1 reduces the catalytic barrier through affecting the activation entropy instead of enthalpy. Site-directed mutagenesis combined with molecular dynamics simulations demonstrated that V149 in the thumb loop of Cbf5 is critical in placing the target uridine to the right position toward catalytic D85 of Cbf5. The enzyme elegantly aligns the position of uridine in the catalytic site with the help of Gar1. In addition, conversion of uridine to pseudouridine results in a rigid syn configuration of the target nucleotide in the active site and causes Gar1 to pull out the thumb. Both factors guarantee the efficient release of the product. PMID:26206671

  8. Accurate Interpretation of the 12-Lead ECG Electrode Placement: A Systematic Review

    ERIC Educational Resources Information Center

    Khunti, Kirti

    2014-01-01

    Background: Coronary heart disease (CHD) patients require monitoring through ECGs; the 12-lead electrocardiogram (ECG) is considered to be the non-invasive gold standard. Examples of incorrect treatment because of inaccurate or poor ECG monitoring techniques have been reported in the literature. The findings that only 50% of nurses and less than…

  9. Accurate placement of substrate RNA by Gar1 in H/ACA RNA-guided pseudouridylation.

    PubMed

    Wang, Peng; Yang, Lijiang; Gao, Yi Qin; Zhao, Xin Sheng

    2015-09-01

    H/ACA RNA-guided ribonucleoprotein particle (RNP), the most complicated RNA pseudouridylase so far known, uses H/ACA guide RNA for substrate capture and four proteins (Cbf5, Nop10, L7Ae and Gar1) for pseudouridylation. Although it was shown that Gar1 not only facilitates the product release, but also enhances the catalytic activity, the chemical role that Gar1 plays in this complicated machinery is largely unknown. Kinetics measurement on Pyrococcus furiosus RNPs at different temperatures making use of fluorescence anisotropy showed that Gar1 reduces the catalytic barrier through affecting the activation entropy instead of enthalpy. Site-directed mutagenesis combined with molecular dynamics simulations demonstrated that V149 in the thumb loop of Cbf5 is critical in placing the target uridine to the right position toward catalytic D85 of Cbf5. The enzyme elegantly aligns the position of uridine in the catalytic site with the help of Gar1. In addition, conversion of uridine to pseudouridine results in a rigid syn configuration of the target nucleotide in the active site and causes Gar1 to pull out the thumb. Both factors guarantee the efficient release of the product. PMID:26206671

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Automatic needle segmentation in 3D ultrasound images using 3D improved Hough transform

    NASA Astrophysics Data System (ADS)

    Zhou, Hua; Qiu, Wu; Ding, Mingyue; Zhang, Songgen

    2008-03-01

    3D ultrasound (US) is a new technology that can be used for a variety of diagnostic applications, such as obstetrical, vascular, and urological imaging, and has been explored greatly potential in the applications of image-guided surgery and therapy. Uterine adenoma and uterine bleeding are the two most prevalent diseases in Chinese woman, and a minimally invasive ablation system using a needle-like RF button electrode is widely used to destroy tumor cells or stop bleeding. To avoid accidents or death of the patient by inaccurate localizations of the electrode and the tumor position during treatment, 3D US guidance system was developed. In this paper, a new automated technique, the 3D Improved Hough Transform (3DIHT) algorithm, which is potentially fast, accurate, and robust to provide needle segmentation in 3D US image for use of 3D US imaging guidance, was presented. Based on the coarse-fine search strategy and a four parameter representation of lines in 3D space, 3DIHT algorithm can segment needles quickly, accurately and robustly. The technique was evaluated using the 3D US images acquired by scanning a water phantom. The segmentation position deviation of the line was less than 2mm and angular deviation was much less than 2°. The average computational time measured on a Pentium IV 2.80GHz PC computer with a 381×381×250 image was less than 2s.

  16. Placement of the acetabular component.

    PubMed

    Beverland, D E; O'Neill, C K J; Rutherford, M; Molloy, D; Hill, J C

    2016-01-01

    Ideal placement of the acetabular component remains elusive both in terms of defining and achieving a target. Our aim is to help restore original anatomy by using the transverse acetabular ligament (TAL) to control the height, depth and version of the component. In the normal hip the TAL and labrum extend beyond the equator of the femoral head and therefore, if the definitive acetabular component is positioned such that it is cradled by and just deep to the plane of the TAL and labrum and is no more than 4mm larger than the original femoral head, the centre of the hip should be restored. If the face of the component is positioned parallel to the TAL and psoas groove the patient specific version should be restored. We still use the TAL for controlling version in the dysplastic hip because we believe that the TAL and labrum compensate for any underlying bony abnormality. The TAL should not be used as an aid to inclination. Worldwide, > 75% of surgeons operate with the patient in the lateral decubitus position and we have shown that errors in post-operative radiographic inclination (RI) of > 50° are generally caused by errors in patient positioning. Consequently, great care needs to be taken when positioning the patient. We also recommend 35° of apparent operative inclination (AOI) during surgery, as opposed to the traditional 45°. PMID:26733639

  17. 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.

  18. 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

  19. SU-E-T-373: A Motorized Stage for Fast and Accurate QA of Machine Isocenter

    SciTech Connect

    Moore, J; Velarde, E; Wong, J

    2014-06-01

    Purpose: Precision delivery of radiation dose relies on accurate knowledge of the machine isocenter under a variety of machine motions. This is typically determined by performing a Winston-Lutz test consisting of imaging a known object at multiple gantry/collimator/table angles and ensuring that the maximum offset is within specified tolerance. The first step in the Winston-Lutz test is careful placement of a ball bearing at the machine isocenter as determined by repeated imaging and shifting until accurate placement has been determined. Conventionally this is performed by adjusting a stage manually using vernier scales which carry the limitation that each adjustment must be done inside the treatment room with the risks of inaccurate adjustment of the scale and physical bumping of the table. It is proposed to use a motorized system controlled outside of the room to improve the required time and accuracy of these tests. Methods: The three dimensional vernier scales are replaced by three motors with accuracy of 1 micron and a range of 25.4mm connected via USB to a computer in the control room. Software is designed which automatically detects the motors and assigns them to proper axes and allows for small shifts to be entered and performed. Input values match calculated offsets in magnitude and sign to reduce conversion errors. Speed of setup, number of iterations to setup, and accuracy of final placement are assessed. Results: Automatic BB placement required 2.25 iterations and 13 minutes on average while manual placement required 3.76 iterations and 37.5 minutes. The average final XYZ offsets is 0.02cm, 0.01cm, 0.04cm for automatic setup and 0.04cm, 0.02cm, 0.04cm for manual setup. Conclusion: Automatic placement decreased time and repeat iterations for setup while improving placement accuracy. Automatic placement greatly reduces the time required to perform QA.

  20. 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

  1. 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

  2. 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

  3. 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

  4. An MBO Approach to Placement Office Evaluation

    ERIC Educational Resources Information Center

    Storholm, Gordon R.

    1978-01-01

    This article investigates the basic functions and responsibilities of the college or university placement director and attempts to translate them into a specific MBO-oriented performance valuation format. (Author)

  5. Student life - Tips for placement success.

    PubMed

    2016-03-01

    Placements are an inevitable part of a nursing degree which provide a platform for on-the-job learning and development, greatly enhancing a student nurse's understanding of their career choice. PMID:26932655

  6. Educational Placement of Children with Spina Bifida.

    ERIC Educational Resources Information Center

    Lauder, Calvin E.; And Others

    1979-01-01

    Procedures of school placement for 38 children (ages 5 to 18 years) with spina bifida in 23 school districts in western New York State were studied 5 years after a mandated process was enacted. (Author)

  7. Nerves and excitement on my first placement.

    PubMed

    Cowen, Emma

    2016-09-12

    After working in the children's accident and emergency department as a healthcare assistant for three years before starting university, I am about to start a placement there as a nursing student. PMID:27615579

  8. 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.

  9. Minimally invasive diagnosis of a pericardial mass by CT-guided fine-needle aspiration.

    PubMed

    Llibre, Cinta; Saenz-Sardà, Xavier; Vilalta, Victòria; Tria, Laura; Llatjós, Maria; Ariza, Aurelio; Bayes-Genis, Antoni

    2016-01-01

    The preferred management of a cardiac mass remains controversial, but it often includes open-chest surgical excision to obtain an adequate tissue sample for histological workup. We herein report a less invasive approach in which an accurate and timely cytological diagnosis of pericardial angiosarcoma was reached by studying a CT-guided fine-needle aspiration cell block. The cell block showed proliferation of atypical cells with occasional mitotic figures, vasoformative features, and immunoreactivity to WT1, vimentin, CD31, CD34, ERG, and Ki67. Recourse to fine-needle aspiration and cell block study is a valuable diagnostic approach to be considered when a cardiac mass is percutaneously accessible. PMID:27131516

  10. Development of the force-feedback model for an epidural needle insertion simulator.

    PubMed

    Hiemenz, L; Stredney, D; Schmalbrock, P

    1998-01-01

    The Ohio Supercomputer Center and the Department of Anesthesiology at the OSU Medical Center have developed a computer-based simulation system for use in training anesthesiology residents in the technique of placing a needle for an epidural block. Although the simulator has been well regarded, the fidelity of the haptic feedback is limited because it is based on subjective expert-user evaluation and not on objective model-based or data-based empirical methods. Only a single degree of freedom for force-feedback is required. However, the simulation must be able to accurately portray the force required to puncture each layer of tissue in order to feel realistic. The purpose of the research described in this paper was to devise a methodology for creating empirically based realistic force-feedback models for the epidural needle insertion procedure using MRI data and biomechanical data from materials testing. PMID:10180553

  11. 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

  12. Cytological diagnosis of metastatic malignant melanoma by fine-needle aspiration biopsy.

    PubMed

    Lindsey, Kathryn G; Ingram, Courtney; Bergeron, Joseph; Yang, Jack

    2016-07-01

    Despite increased surveillance and public awareness, the incidence of melanoma is increasing. Frequently, fine-needle aspiration is employed for the diagnosis of metastatic disease, and aspirated material is used for cytogenetic and molecular studies to guide treatment options. The pairing of a significant diagnosis with the numerous morphologic variants of melanoma can make the cytologic evaluation disquieting. We present selected examples of our experiences and a brief review of the literature to provide cytodiagnostic clues for this malignancy. The clinical history is foremost, although the fine-needle aspiration (FNA) of metastatic melanoma can provide a diagnosis before identification of the primary lesion in up to 20% of cases. If a history of melanoma is assured, negative results in sampling of pulmonary and subcutaneous nodules should be suspected as false negatives. The smearing pattern usually features poorly cohesive cells. Frankly malignant, spindled, and epithelioid cell shapes are most common, and cytoplasmic vacuoles, if sought on Romanowsky-stained specimens, can usually be found. The telltale feature of melanin production, although diagnostic, is only present in 50% of cases. Finally, eccentric placement of nuclei, nucleoli, and nuclear pseudoinclusions are accessory features for the cytologic interpretation of melanoma. Numerous morphologic patterns of melanoma are potentially seen, but a stepwise approach to diagnosis usually produces a successful result. PMID:27199077

  13. Hybrid reflection type metasurface of nano-antennas designed for optical needle field generation

    NASA Astrophysics Data System (ADS)

    Wang, Shiyi; Zhan, Qiwen

    2015-03-01

    We propose a reflection type metal-insulator-metal (MIM) metasurface composed of hybrid optical antennas for comprehensive spatial engineering the properties of optical fields. Its capability is illustrated with an example to create a radially polarized vectorial beam for optical needle field generation. Functioning as local quarter-wave-plates (QWP), the MIM metasurface is designed to convert circularly polarized incident into local linear polarization to create an overall radial polarization with corresponding binary phases and desired normalized amplitude modulation ranged from 0.07 to 1. To obtain enough degrees of freedom, the optical-antenna layer comprises periodic arrangements of double metallic nano-bars with perpendicular placement and single nano-bars respectively for different amplitude modulation requirements. Both of the antennas enable to introduce π/2 retardation while reaching the desired modulation range both for phase and amplitude. Through adjusting the antennas' geometry and array carefully, we shift the gap-surface plasmon resonances facilitated by optical antennas to realize the manipulation of vectorial properties. Designed at 1064 nm wavelength, the particularly generated vectorial light output can be further tightly focused by a high numerical aperture objective to obtain longitudinally polarized flat-top focal field. The so-called optical needle field is a promising candidate for novel applications that transcend disciplinary boundaries. The proposed metasurface establishes a new class of compact optical components based on nano-scale structures, leading to compound functions for vectorial light generation.

  14. [Navigated implant placement using a bone supported CT-guided surgical template. Case report].

    PubMed

    Teubner, Eckart; Rohner, Dennis; Deak, Alexander; Lorenzon, Andreas; Marinello, Carlo P

    2009-01-01

    Surgical navigation allows precise implant placement and minimizes the risk of interferences with anatomical structures. Computerized implant planning based on tomographic data can be clinically realized by surgical templates. These are normally produced by stereo lithographic rapid prototyping. Accurate placement of virtually planned dental implants depends on a precise fabrication and positioning of the surgical template. Bone-, tooth-, implant-, and/or soft tissue-supported surgical templates allow for different micromovements. This report documents the diagnostics and surgical procedures of implant placement in an edentulous patient. Implant fixed complete dentures in the maxilla and mandible were planned. In the maxilla implants were inserted with the aid of a conventional surgical template. In the mandible a bone supported CT-guided surgical template was used. PMID:20120091

  15. 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

  16. Exploring continuous clinical placement for undergraduate students.

    PubMed

    McKenna, Lisa G; Wray, Natalie; McCall, Louise

    2009-08-01

    Clinical placements are integral to health professional preparatory courses. These placements allow for the application of classroom-based learning into real patient care situations. In doing so, they provide opportunities for applying theoretical knowledge into practice contexts, skills development and socialisation into the chosen profession. However, despite its recognised importance across health professions, little has been written about optimal structures for supporting clinical learning. This paper presents one group of findings from a larger qualitative study aimed at exploring health professional student's clinical experiences and their impact on career intentions. Findings reported here present a group of undergraduate midwifery student's perspectives on a "home" hospital clinical placement model where continuous clinical placements were taken in the same agency (or hospital group) for 2 days per week over the final 2 years of their course. Two main themes emerged from the data analysis, these being, 'familiarity' and 'continuity'. It is concluded that continuous placements in the same clinical setting have the potential to offer greater opportunities for learning and early professional socialisation than traditional block (Monday to Friday) placements. They can offer a more integrated approach to classroom theory and its application into practice. PMID:18427942

  17. Conductivity Probe after Trench-Bottom Placement

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Needles of the thermal and conductivity probe on NASA's Phoenix Mars Lander were positioned into the bottom of a trench called 'Upper Cupboard' during Sol 86 (Aug. 21, 2008), or 86th Martian day after landing. This image of the conductivity probe after it was raised back out of the trench was taken by Phoenix's Robotic Arm Camera. The conductivity probe is at the wrist of the robotic arm's scoop.

    The probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  18. 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

  19. 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

  20. Modified algesimeter provides accurate depth measurements

    NASA Technical Reports Server (NTRS)

    Turner, D. P.

    1966-01-01

    Algesimeter which incorporates a standard sensory needle with a sensitive micrometer, measures needle point depth penetration in pain tolerance research. This algesimeter provides an inexpensive, precise instrument with assured validity of recordings in those biomedical areas with a requirement for repeated pain detection or ascertaining pain sensitivity.

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. College Mathematics Placement Tests: Student Perceptions of Preparation and Appropriateness of Placement

    ERIC Educational Resources Information Center

    Magee, Pamela Ann

    2010-01-01

    An increasing number of recent high school graduates' college math placement test results indicate that they are not ready for college level math. This study examined the perceptions of recent high school graduates enrolled in developmental math classes to determine their level of satisfaction with their math placement, the relationship of…

  11. 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

  12. Advanced tow placement of composite fuselage structure

    NASA Technical Reports Server (NTRS)

    Anderson, Robert L.; Grant, Carroll G.

    1992-01-01

    The Hercules NASA ACT program was established to demonstrate and validate the low cost potential of the automated tow placement process for fabrication of aircraft primary structures. The program is currently being conducted as a cooperative program in collaboration with the Boeing ATCAS Program. The Hercules advanced tow placement process has been in development since 1982 and was developed specifically for composite aircraft structures. The second generation machine, now in operation at Hercules, is a production-ready machine that uses a low cost prepreg tow material form to produce structures with laminate properties equivalent to prepreg tape layup. Current program activities are focused on demonstration of the automated tow placement process for fabrication of subsonic transport aircraft fuselage crown quadrants. We are working with Boeing Commercial Aircraft and Douglas Aircraft during this phase of the program. The Douglas demonstration panels has co-cured skin/stringers, and the Boeing demonstration panel is an intricately bonded part with co-cured skin/stringers and co-bonded frames. Other aircraft structures that were evaluated for the automated tow placement process include engine nacelle components, fuselage pressure bulkheads, and fuselage tail cones. Because of the cylindrical shape of these structures, multiple parts can be fabricated on one two placement tool, thus reducing the cost per pound of the finished part.

  13. Preparing health students for interprofessional placements.

    PubMed

    Grace, Sandra; McLeod, Gopi; Streckfuss, Julie; Ingram, Lissa; Morgan, Annette

    2016-03-01

    Clinical education increasingly includes opportunities for interprofessional (IP) placements but few opportunities for students and supervisors to adequately prepare for such placements. The aim of this project was to further develop and evaluate an online multidisciplinary resource that was originally designed to prepare students for single-discipline placements. The revised resource aimed to prepare health students and their supervisors for IP placements. The resource was trialled in host organisations with participants from naturopathy, nursing, osteopathy and pharmacy. The resource used language that was common to all participants and comprised activities that had broad relevance such as orientating students to specific placements, developing learning plans, clarifying roles, rights and responsibilities, and clinical scenarios that raised ethical and professional issues. The effectiveness of the resource as an IP learning tool was evaluated using an E-survey, focus groups and feedback from the project team. According to participants, the resource afforded insights into what other disciplines do and opportunities for cross-disciplinary interactions, which helped break down stereotypes and misconceptions. Cross-disciplinary commonalities such as those pertaining to patient care, communication and ethics became evident. Collaborative projects involving academics, clinical supervisors and students from multiple disciplines provided an opportunity for culture change in an education organisation from single discipline to a more collaborative interdisciplinary one. PMID:27038083

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. Development of a nanowire based titanium needle probe sensor for glucose monitoring

    NASA Astrophysics Data System (ADS)

    Deshpande, Devesh C.

    The need for continuous monitoring of various physiological functions such as blood glucose levels, neural functions and cholesterol levels has fostered the research and development of various schemes of biosensors to sense and help control the respective function. The needs of patients for sensors with minimal discomfort, longer life and better performance have necessitated the development towards smaller and more efficient sensors. In addition, the need for higher functionality from smaller sensors has led to the development of sensors with multiple electrodes, each electrode capable of sensing a different body function. Such multi-electrode sensors need to be fabricated using micro-fabrication processes in order to achieve precise control over the size, shape and placement of the electrodes. Multielectrode sensors fabricated using silicon and polymers have been demonstrated. One physiological function that attracts widespread interest is continuous glucose monitoring in our blood, since Diabetes affects millions of people all over the world. Significant deviations of blood glucose levels from the normal levels of 4-8 mM can cause fainting, coma and damage to the eyes, kidneys, nerves and blood vessels. For chronic patients, continuous monitoring of glucose levels is essential for accurate and timely treatment. A few continuous monitoring sensors are available in the market, but they have problems and cannot replace the strip type one-time glucose monitoring systems as yet. To address this need, large scale research efforts have been targeted towards continuous monitoring. The demand for higher accuracy and sensitivity has motivated researchers to evaluate the use of nanostructures in sensing. The large surface area-to-volume ratio of such structures could enable further miniaturization and push the detection limits, potentially enabling even single molecule detection. This research involved the development of a biocompatible titanium needle probe sensor for

  20. Feedback and assessment for clinical placements: achieving the right balance

    PubMed Central

    Burgess, Annette; Mellis, Craig

    2015-01-01

    During clinical placements, the provision of feedback forms an integral part of the learning process and enriches students’ learning experiences. The purpose of feedback is to improve the learner’s knowledge, skills, or behavior. Receipt of accurate feedback can help to narrow the gap between actual and desired performance. Effective and regular feedback has the potential to reinforce good practice and motivate the learner toward the desired outcome. Despite the obvious role of feedback in effective teaching and learning, a common complaint from students is that they do not receive adequate feedback. Unfortunately, skills in giving and receiving feedback are rarely taught to students or clinicians. This study aims to provide an understanding of the role of feedback within the learning process, consider consequences of inadequate or poorly given feedback, consider the barriers to the feedback process, provide practical guidelines for providing feedback, and consider the need for student and faculty development in feedback skills. PMID:26056511

  1. Component placement optimization in the brain.

    PubMed

    Cherniak, C

    1994-04-01

    This computational neuroanatomy study evaluates how well some formalisms derived from combinatorial network optimization theory fit as models for brain structure. At multiple hierarchical levels--brain, ganglion, individual cell--physical placement of neural components appears consistent with a single, simple goal: minimize cost of connections among the components. The most dramatic instance of this "save wire" organizing principle is reported for adjacencies among ganglia in the nematode nervous system; among about 40,000,000 alternative layout orderings, the actual ganglion placement in fact requires the least total connection length. In addition, evidence supports a component placement optimization hypothesis for positioning of individual neurons in the nematode, and also for positioning of mammalian cortical areas. PMID:8158278

  2. Pregnancy Outcomes After Myomectomy With Polytetrafluoroethylene Placement

    PubMed Central

    Milad, Magdy P.

    2014-01-01

    Background and Objectives: The aim of this study was to report preliminary data on pregnancy outcomes after myomectomy with placement of an expanded polytetrafluoroethylene adhesion barrier membrane. Methods: In this retrospective case series, 68 women who underwent myomectomy with expanded polytetrafluoroethylene membrane placement between January 1, 2003, and December 31, 2009, were identified. Of these women, 15 subsequently had documented pregnancies and were included in the final dataset. Results: Eighteen pregnancies were documented among 15 women. There were no reported cases of preterm labor, preterm premature rupture of membranes, or uterine rupture. Conclusion: In this case series, there were no documented cases of preterm labor, preterm premature rupture of membranes, or uterine rupture after myomectomy with expanded polytetrafluoroethylene membrane placement. PMID:25392651

  3. Endoscopic Gold Fiducial Marker Placement into the Bladder Wall to Optimize Radiotherapy Targeting for Bladder-Preserving Management of Muscle-Invasive Bladder Cancer: Feasibility and Initial Outcomes

    PubMed Central

    Garcia, Maurice M.; Gottschalk, Alexander R.; Brajtbord, Jonathan; Konety, Badrinath R.; Meng, Maxwell V.; Roach, Mack; Carroll, Peter R.

    2014-01-01

    Background and Purpose Bladder radiotherapy is a management option for carefully selected patients with muscle-invasive bladder cancer. However, the inability to visualize the tumor site during treatment and normal bladder movement limits targeting accuracy and increases collateral radiation. A means to accurately and reliably target the bladder during radiotherapy is needed. Materials and Methods Eighteen consecutive patients with muscle-invasive bladder cancer (T1–T4) elected bladder-preserving treatment with maximal transurethral resection (TUR), radiation and concurrent chemotherapy. All underwent endoscopic placement of 24-K gold fiducial markers modified with micro-tines (70 [2.9×0.9 mm.]; 19 [2.1×0.7 mm.) into healthy submucosa 5-10 mm. from the resection margin, using custom-made coaxial needles. Marker migration was assessed for with intra-op bladder-filling cystogram and measurement of distance between markers. Set-up error and marker retention through completion of radiotherapy was confirmed by on-table portal imaging. Results Between 1/2007 and 7/2012, a total of 89 markers (3–5 per tumor site) were placed into 18 patients of mean age 73.6 years. Two patients elected cystectomy before starting treatment; 16/18 completed chemo-radiotherapy. All (100%) markers were visible with all on-table (portal, cone-beam CT), fluoroscopy, plain-film, and CT-scan imaging. In two patients, 1 of 4 markers placed at the tumor site fell-out (voided) during the second half of radiotherapy. All other markers (80/82, 98%) were present through the end of radio-therapy. No intraoperative (e.g. uncontrolled bleeding, collateral injury) or post-operative complications (e.g. stone formation, urinary tract infection, post-TUR hematuria >48 hours) occurred. Use of micro-tined fiducial tumor-site markers afforded a 2 to 6-fold reduction in bladder-area targeted with high-dose radiation. Discussion Placement of the micro-tined fiducial markers into the bladder was feasible and

  4. Fine needle aspiration biopsy in pediatric ophthalmic tumors and pseudotumors.

    PubMed

    O'Hara, B J; Ehya, H; Shields, J A; Augsburger, J J; Shields, C L; Eagle, R C

    1993-01-01

    In an eight-year period (1983-1990) approximately 500 fine needle aspiration biopsies (FNABs) of eye lesions were processed in our laboratory. Eighty-one of the cases, obtained from 77 pediatric patients (ranging from 4 weeks to 16 years of age), were the subject of this study. The specimens included 73 intraocular and 8 orbital aspirates. Forty-four of the specimens were from diagnostic procedures, whereas 37 were obtained from surgical specimens immediately after enucleation. Eight FNABs (four diagnostic and four postenucleation) were deemed inadequate for cytologic diagnosis. Of the remaining 73 cases, 38 were diagnosed as malignant (34 retinoblastomas, 3 medulloepitheliomas, 1 rhabdomyosarcoma), and all were confirmed upon subsequent histologic examination. Four cases were diagnosed as suspicious for malignancy; all of them proved to be malignant (two retinoblastomas, two rhabdomyosarcomas). One orbital aspirate contained cells suggestive of a glial origin and was confirmed histologically as pilocytic astrocytoma. Ten cases were reported as compatible with Coats' disease; all were confirmed to be benign by histologic examination (three cases) or clinical follow-up (seven cases). The remaining 20 benign aspirates (13 with inflammatory cells, 6 with macrophages and 1 with blood) proved to be from benign conditions by histologic examination (4 cases) or clinical follow-up (16 cases). There were no false-positive diagnoses. The overall accuracy of FNAB was 95%, and the accuracy of cytologic interpretation was 100%. We conclude that FNAB is a reliable and accurate diagnostic modality in the assessment of selected pediatric ophthalmic diseases. PMID:8465629

  5. Design of a multi-needle Langmuir probe system

    NASA Astrophysics Data System (ADS)

    Bekkeng, T. A.; Jacobsen, K. S.; Bekkeng, J. K.; Pedersen, A.; Lindem, T.; Lebreton, J.-P.; Moen, J. I.

    2010-08-01

    The main goal of this work was to develop a Langmuir probe instrument for sounding rockets capable of performing high-speed absolute electron density measurements, and thereby be able to detect sub-meter ionospheric plasma density structures. The system comprises four cylindrical probes with a diameter of 0.51 mm and a length of 25 mm, each operated at a different fixed bias voltage in the electron saturation region. The probe diameter was chosen significantly less than the Debye shielding length to avoid complex sheath effects but large enough to ensure a probe area sufficiently large to accurately measure the electron currents drawn by the probes (in the range 1 nA to 1 µA). The crucial feature of the University of Oslo's multi-needle Langmuir probe (m-NLP) is that it is possible to determine the electron density without the need to know the spacecraft potential and the electron temperature Te. The m-NLP instrument covers a density range from ne = 109 m-3 to 1012 m-3, with sampling rates up to 9 kHz. The m-NLP instrument was successfully tested on the ICI-2 (Investigation of Cusp Irregularities) sounding rocket flight from Svalbard on 5 December 2008.

  6. Toward improving fine needle aspiration cytology by applying Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Becker-Putsche, Melanie; Bocklitz, Thomas; Clement, Joachim; Rösch, Petra; Popp, Jürgen

    2013-04-01

    Medical diagnosis of biopsies performed by fine needle aspiration has to be very reliable. Therefore, pathologists/cytologists need additional biochemical information on single cancer cells for an accurate diagnosis. Accordingly, we applied three different classification models for discriminating various features of six breast cancer cell lines by analyzing Raman microspectroscopic data. The statistical evaluations are implemented by linear discriminant analysis (LDA) and support vector machines (SVM). For the first model, a total of 61,580 Raman spectra from 110 single cells are discriminated at the cell-line level with an accuracy of 99.52% using an SVM. The LDA classification based on Raman data achieved an accuracy of 94.04% by discriminating cell lines by their origin (solid tumor versus pleural effusion). In the third model, Raman cell spectra are classified by their cancer subtypes. LDA results show an accuracy of 97.45% and specificities of 97.78%, 99.11%, and 98.97% for the subtypes basal-like, HER2+/ER-, and luminal, respectively. These subtypes are confirmed by gene expression patterns, which are important prognostic features in diagnosis. This work shows the applicability of Raman spectroscopy and statistical data handling in analyzing cancer-relevant biochemical information for advanced medical diagnosis on the single-cell level.

  7. A new sensor technology for 2D ultrasound-guided needle tracking.

    PubMed

    Lu, Huanxiang; Li, Junbo; Lu, Qiang; Bharat, Shyam; Erkamp, Ramon; Chen, Bin; Drysdale, Jeremy; Vignon, Francois; Jain, Ameet

    2014-01-01

    2D Ultrasound (US) is becoming the preferred modality for image-guided interventions due to its low cost and portability. However, the main limitation is the limited visibility of surgical tools. We present a new sensor technology that can easily be embedded on needles that are used for US-guided interventions. Two different types of materials are proposed to be used as sensor--co-polymer and PZT. The co-polymer technology is particularly attractive due to its plasticity, allowing very thin depositions (10-20 μm) on a variety of needle shapes. Both sensors receive acoustic energy and convert it to an electrical signal. The precise location of the needle can then be estimated from this signal, to provide real-time feedback to the clinician. We evaluated the feasibility of this new technology using (i) a 4DOF robot in a water tank; (ii) extensive ex vivo experiments; and (iii) in vivo studies. Quantitative robotic studies indicated that the co-polymer is more robust and stable when compared to PZT. In quantitative experiments, the technology achieved a tracking accuracy of 0.14 ± 0.03mm, significantly superior to competing technologies. The technology also proved success in near-real clinical studies on tissue data. This sensor technology is non-disruptive of existing clinical workflows, highly accurate, and is cost-effective. Initial clinician feedback shows great potential for large scale clinical impact. PMID:25485403

  8. Needles: Toward Large-Scale Genomic Prediction with Marker-by-Environment Interaction.

    PubMed

    De Coninck, Arne; De Baets, Bernard; Kourounis, Drosos; Verbosio, Fabio; Schenk, Olaf; Maenhout, Steven; Fostier, Jan

    2016-05-01

    Genomic prediction relies on genotypic marker information to predict the agronomic performance of future hybrid breeds based on trial records. Because the effect of markers may vary substantially under the influence of different environmental conditions, marker-by-environment interaction effects have to be taken into account. However, this may lead to a dramatic increase in the computational resources needed for analyzing large-scale trial data. A high-performance computing solution, called Needles, is presented for handling such data sets. Needles is tailored to the particular properties of the underlying algebraic framework by exploiting a sparse matrix formalism where suited and by utilizing distributed computing techniques to enable the use of a dedicated computing cluster. It is demonstrated that large-scale analyses can be performed within reasonable time frames with this framework. Moreover, by analyzing simulated trial data, it is shown that the effects of markers with a high environmental interaction can be predicted more accurately when more records per environment are available in the training data. The availability of such data and their analysis with Needles also may lead to the discovery of highly contributing QTL in specific environmental conditions. Such a framework thus opens the path for plant breeders to select crops based on these QTL, resulting in hybrid lines with optimized agronomic performance in specific environmental conditions. PMID:26936924

  9. Multi-needle capacitance probe for non-conductive two-phase flows

    NASA Astrophysics Data System (ADS)

    Monrós-Andreu, G.; Martinez-Cuenca, R.; Torró, S.; Escrig, J.; Hewakandamby, B.; Chiva, S.

    2016-07-01

    Despite its variable degree of application, intrusive instrumentation is the most accurate way to obtain local information in a two-phase flow system, especially local interfacial velocity and local interfacial area parameters. In this way, multi-needle probes, based on conductivity or optical principles, have been extensively used in the past few decades by many researchers in two-phase flow investigations. Moreover, the signal processing methods used to obtain the time-averaged two-phase flow parameters in this type of sensor have been thoroughly discussed and validated by many experiments. The objective of the present study is to develop a miniaturized multi-needle probe, based on capacitance measurements applicable to a wide range of non-conductive two-phase flows and, thus, to extend the applicability of multi-needle sensor whilst also maintaining a signal processing methodology provided in the literature for conductivity probes. Results from the experiments performed assess the applicability of the proposed sensor measurement principle and signal processing method for the bubbly flow regime. These results also provide an insight into the sensor application for more complex two-phase flow regimes.

  10. Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data

    USGS Publications Warehouse

    Waite, W.F.; Gilbert, L.Y.; Winters, W.J.; Mason, D.H.

    2006-01-01

    Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained from a linear fit to many tens or hundreds of temperature change data points. In contrast, thermal diffusivity calculations require a nonlinear fit to the measured temperature change occurring in the first few tenths of a second of the measurement, resulting in a lower accuracy than that obtained for thermal conductivity. Specific heat is calculated from the ratio of thermal conductivity to diffusivity, and thus can have an uncertainty no better than that of the diffusivity estimate. Our thermal conductivity measurements of ice Ih and of tetrahydrofuran (THF) hydrate, made using a 1.6 mm outer diameter needle probe and a data acquisition rate of 18.2 pointss, agree with published results. Our thermal diffusivity and specific heat results reproduce published results within 25% for ice Ih and 3% for THF hydrate. ?? 2006 American Institute of Physics.

  11. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  12. Fully customized placement of orthodontic miniplates: a novel clinical technique

    PubMed Central

    2014-01-01

    Introduction The initial stability and survival rate of orthodontic mini-implants are highly dependent on the amount of cortical bone at their insertion site. In areas with limited bone availability, mini-plates are preferred to provide effective skeletal anchorage. The purpose of this paper was to present a new clinical technique for the insertion of mini-plates. Methods In order to apply this new technique, a cone-beam image of the insertion area is required. A software (Galaxy Sirona, Bensheim, Germany) is used to construct a three-dimensional image of the scanned area and to virtually determine the exact location of the mini-plate as well as the position of the fixation screws. A stereolithographic model (STL) is then created by means of a three-dimensional scanner. Prior to its surgical insertion, the bone plate is adapted to the stereo-lithographic model. Finally, a custom transfer jig is fabricated in order to assist with accurate placement of the mini-plate intra-operatively. Results The presented technique minimizes intra-operative decision making, because the final position of the bone plate is determined pre-surgically. This significantly reduces the duration of the surgical procedure and improves its outcome. Conclusions A novel method for surgical placement of orthodontic mini-plates is presented. The technique facilitates accurate adaptation of mini-plates and insertion of retaining surgical screws; thereby enabling clinicians to more confidently increase the use of bone plates, especially in anatomical areas where the success of non-osseointegrated mini-screws is less favorable. PMID:24886597

  13. Analytic theory for the selection of a two-dimensional needle crystal at arbitrary Peclet number

    NASA Technical Reports Server (NTRS)

    Tanveer, S.

    1989-01-01

    An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.

  14. Analytic theory for the selection of 2-D needle crystal at arbitrary Peclet number

    NASA Technical Reports Server (NTRS)

    Tanveer, Saleh

    1989-01-01

    An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.

  15. Performance consequences of parity placement in disk arrays

    NASA Technical Reports Server (NTRS)

    Lee, Edward K.; Katz, Randy H.

    1991-01-01

    The performance of a variety of parity placement schemes are defined and investigated to demonstrate that, at relatively large request sizes of hundreds of kilobytes, the choice of parity placement significantly affects performance (20 to 30 percent for the disk array configurations that are common today). It is shown that the left-symmetric, extended-left-symmetric and flat-left-symmetric are the best RAID level 5 parity placements. The placement with the highest read performance, flat-left-symmetric, has the lowest write performance, while the placement with the lowest read performance, left-symmetric, has the highest write performance. Suggestions for optimizing parity placements are included.

  16. Optimization Strategies for Sensor and Actuator Placement

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Kincaid, Rex K.

    1999-01-01

    This paper provides a survey of actuator and sensor placement problems from a wide range of engineering disciplines and a variety of applications. Combinatorial optimization methods are recommended as a means for identifying sets of actuators and sensors that maximize performance. Several sample applications from NASA Langley Research Center, such as active structural acoustic control, are covered in detail. Laboratory and flight tests of these applications indicate that actuator and sensor placement methods are effective and important. Lessons learned in solving these optimization problems can guide future research.

  17. Atraumatic extraction, implant placement and immediate provisionalization.

    PubMed

    Tavarez, Rudys Rodolfo de Jesus; Calixto, Amanda Martins; Maia Filho, Etevaldo Matos; Bandeca, Matheus Coelho; Firoozmand, Leily Macedo; Gomes, Mario Gilson Nina; Malheiros, Adriana Santos

    2014-01-01

    Front tooth extraction typically results in significant loss of hard and soft tissue volume, both in the vestibular-lingual and mesiodistal directions. As these changes can compromise the esthetic results of prosthetic rehabilitation, extraction techniques that cause minimal trauma to the remnant tissues are applied in combination with immediate implant placement to minimize such alterations. The case reported in the present article illustrates a therapeutic plan consisting of atraumatic extraction followed by immediate implant placement and provisionalization. When carefully indicated and planned, our results indicate that this technique may provide promising immediate results relative to the maintenance and stability of the peri-implanted tissues. PMID:25576122

  18. Fat-Suppressed Gadolinium-Enhanced Three-Dimensional Magnetic Resonance Angiography Adequately Depicts the Status of Iliac Arteries Following Atherectomy and Stent Placement

    SciTech Connect

    Amano, Yasuo; Gemma, Kazuhito; Kawamata, Hiroshi; Kumazaki, Tatsuo

    1998-07-15

    Fat-suppressed, three-dimensional magnetic resonance angiography (3D MRA) was performed on nine patients with 11 iliac artery stenoses following atherectomy or stent placement. The MRA accurately depicted continued patency, restenosis, or aneurysm formation when compared with immediate posttreatment conventional arteriography. Therefore MRA is accurate and can be used independently for clinical decision making.

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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

  7. 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....

  8. 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....

  9. 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....

  10. 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....

  11. 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....

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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

  18. 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.

  19. 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…

  20. 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...

  1. Diagnosis of Langerhans Cell Histiocytosis on Fine Needle Aspiration Cytology: A Case Report and Review of the Cytology Literature

    PubMed Central

    Kumar, Neeta; Sayed, Shahin; Vinayak, Sudhir

    2011-01-01

    A case of multifocal Langerhans cell histiocytosis in a two-year-old child is presented where fine needle aspiration was helpful in achieving a rapid and accurate diagnosis in an appropriate clinical and radiological setting. This can avoid unnecessary biopsy and guide the management especially where access to histopathology is limited. The highly characteristic common and rare cytological features are highlighted with focus on differential diagnoses and causes of pitfalls. PMID:21331166

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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%.

  7. 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

  8. 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.

  9. Predicting success on the Advanced Placement Biology Examination

    NASA Astrophysics Data System (ADS)

    Shepherd, Lesa Hanlin

    Four hundred sixty students in four public high schools were used as subjects to determine which of eleven academic and demographic factors studied were significant predictors of success for the Advanced Placement Biology Examination. Factors studied were attendance, class rank, gender, grade level at the time of the examination, grade point average, level of prerequisite biology course, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, proposed major in college, race, and SAT mathematics, verbal, and combined score. Significant relationships were found to exist between the Advanced Placement Biology Examination score and attendance, class rank, gender, grade level at the time of the Advanced Placement Biology Examination, grade point average, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, race, and SAT scores. Significant relationships were not found to exist between Advanced Placement Biology Examination score and level prerequisite biology course and Advanced Placement Biology Examination score and proposed major in college. A multiple regression showed the best combination of predictors to be attendance, SAT verbal score, and SAT mathematics score. Discriminant analysis showed the variables in this study to be good predictors of whether the student would pass the Advanced Placement Biology Examination (score a 3, 4, or 5) or fail the Advanced Placement Biology Examination (score a 1 or 2). These results demonstrated that significant predictors for the Advanced Placement Biology Examination do exist and can be used to assist in the prediction of scores, prediction of passing or failing, the identification of

  10. 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

  11. 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

  12. Endobronchial ultrasound-guided sheath placement to guide transbronchial biopsy of mediastinal lymphadenopathy and lung mass: a new technique.

    PubMed

    Harris, Kassem; Bessich, Jamie; Sterman, Daniel H

    2015-04-01

    A patient with a history of lung adenocarcinoma, which was treated with chemoradiation, presented to our interventional pulmonology clinic for suspicion of recurrent lung cancer. The patient had a PET-avid right upper-lobe mass and subcarinal lymphadenopathy. We performed a curvilinear endobronchial ultrasound (CP-EBUS) with transbronchial needle aspiration (TBNA), followed by transbronchial EBUS-guided biopsies (TBB) of the subcarinal lymph node using miniforceps. The EBUS needle sheath was inserted over the needle through the bronchial wall and advanced into the lymph node. The EBUS-guided placement of the transbronchial sheath facilitated the miniforcep insertion and the performance of multiple transbronchial biopsies. Given success with this method, we further developed this technique in a second patient with a right lower-lobe mass. In an effort to obtain adequate tissue and minimize repeated efforts at miniforcep guidance into the lesion, we inserted a radial EBUS guide sheath through the curvilinear EBUS scope and guided it into the lesion using the miniforceps. We therefore used the radial sheath as a placeholder while obtaining repeated TBB using miniforceps as described. These modifications of previously described techniques allow for maximal and expeditious sampling of target lymph nodes and masses, with sufficient material obtained for histopathologic analysis. PMID:25887015

  13. Advanced Placement: Do Minorities Have Equal Opportunity?

    ERIC Educational Resources Information Center

    Klopfenstein, Kristin

    2004-01-01

    Black and Hispanic high school students enroll in Advanced Placement (AP) courses at approximately half the rate of white students. This paper develops a microeconomic model of the AP participation decision and finds that low income is the single most important factor behind the minority AP participation gap. In addition, minority students enroll…

  14. Literary Archetypes. Advanced Placement English Curriculum Guide.

    ERIC Educational Resources Information Center

    Anne Arundel County Public Schools, Annapolis, MD.

    Providing students with the opportunity to earn college credit while still in high school, the Advanced Placement English course described in this guide is designed to help students (1) want to choose from a wide range of literature for independent reading; (2) develop a critical awareness about literature; (3) recognize connections among works of…

  15. Academic Placement after Traumatic Brain Injury.

    ERIC Educational Resources Information Center

    Donders, Jacques

    The acadmic placement of 87 children (ages 6 to 16 years) who had sustained brain injuries was determined within 1 year after initial psychological assessment. Forty-five children had returned full time to regular academic programs, 21 children received special education support for less than half of their classes, and 21 children were enrolled in…

  16. Advanced Placement Economics. Macroeconomics: Student Activities.

    ERIC Educational Resources Information Center

    Morton, John S.

    This book is designed to help advanced placement students better understand macroeconomic concepts through various activities. The book contains 6 units with 64 activities, sample multiple-choice questions, sample short essay questions, and sample long essay questions. The units are entitled: (1) "Basic Economic Concepts"; (2) "Measuring Economic…

  17. Advanced Placement Economics. Microeconomics: Student Activities.

    ERIC Educational Resources Information Center

    Morton, John S.

    This book is designed to help advanced placement students better understand microeconomic concepts through various activities. The book contains 5 units with 73 activities, sample multiple-choice questions, sample short essay questions, and sample long essay questions. The units are entitled: (1) "The Basic Economic Problem"; (2) "The Nature and…

  18. Advanced Placement Economics. Teacher Resource Manual.

    ERIC Educational Resources Information Center

    Morton, John S.

    This book, in conjunction with the student activities books for macroeconomics and microeconomics, is designed for teaching the Advanced Placement Economics course. The book contains five units for the microeconomic portion and six units for the macroeconomic portion of the text. Along with the many activities are sample multiple-choice questions,…

  19. Polytechnic Graduate Placement in Finnish Manufacturing

    ERIC Educational Resources Information Center

    Bockerman, Petri

    2007-01-01

    This paper analyses polytechnic graduate placement in Finnish manufacturing. The paper uses a register-based data source covering white-collar manufacturing workers over the period 1995-2004. Taken together, the results show that wages and job classification are higher for polytechnic graduates, once other covariates are controlled for. Despite…

  20. CAPS: Career Assistance & Placement Services. Resource Manual.

    ERIC Educational Resources Information Center

    Barrow, Connye M.; And Others

    This resource manual describes a model for planning and developing comprehensive career placement services integrated into the total career development efforts of secondary and postsecondary schools in Illinois. The manual is designed to be used by educational administrators at the local and regional level in developing specific program goals,…

  1. 20 CFR 801.103 - Organizational placement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Organizational placement. 801.103 Section 801.103 Employees' Benefits BENEFITS REVIEW BOARD, DEPARTMENT OF LABOR ESTABLISHMENT AND OPERATION OF THE... statute, the functions of the Benefits Review Board are quasi-judicial in nature and involve review...

  2. A simplified stent for placement of miniscrews.

    PubMed

    Hattarki, Rohan

    2012-01-01

    Recently miniscrews have been successfully used in the dentoalveolar area as a source of anchorage for affecting various kinds of tooth movement. However, it is essential to place the miniscrew in the interdental bone, preventing contact with the roots of the adjacent teeth. The present article describes fabrication of a simple stent for the placement of orthodontic miniscrews. PMID:23413640

  3. Institutional Placement: Phases of the Transition.

    ERIC Educational Resources Information Center

    Zarit, Steven H.; Whitlatch, Carol J.

    1992-01-01

    Examined consequences of institutionalization for 555 caregivers of dementia patients. Consistent with stress process model, institutionalization was hypothesized to have large impact on primary effects of caregiving and lesser influence on secondary effects and well-being. Following placement, caregivers experienced relief from primary effects of…

  4. Introduction. Teaching Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Murphy, Alexander B.

    2000-01-01

    Introduces this special issue of "Journal of Geography" focusing on the teaching of Advanced Placement (AP) human geography. States that essays were developed by members of the AP Human Geography Development Committee focusing on areas in the human geography course outline which are included in the appendix. (CMK)

  5. Promoting Paired Placements in Initial Teacher Education

    ERIC Educational Resources Information Center

    King, Sheila

    2006-01-01

    The use of paired placements and collaborative practice is promoted by many university-school partnerships that train teachers in England. This paper reviews the recent literature on the subject and then focuses on some small scale research within initial teacher education in one large university-school partnership. That partnership works with…

  6. Population in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Sharma, Martha B.

    2000-01-01

    Addresses the population section of the Advanced Placement course outline for human geography, focusing on four themes: (1) geographical analysis of population; (2) population distribution and composition; (3) population growth and decline over time and space; and (4) population movement. Identifies strategies for instructional activities.…

  7. Modern Agriculture in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Lanegran, David A.

    2000-01-01

    Discusses the four sections of the Advanced Placement (AP) human geography course focusing on agriculture: (1) development and diffusion of agriculture; (2) major agricultural production regions; (3) rural land use and change; and (4) impacts of modern agricultural change. Includes references and a resource list. (CMK)

  8. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN WITH DISABILITIES State Eligibility Least...

  9. The Rural Clinical Nurse Placement Center.

    ERIC Educational Resources Information Center

    Stuart-Siddall, Sandra; And Others

    The Rural Clinical Nurse Placement Center (RCNP) was begun in Chico, California, in 1975 to develop, implement, evaluate, and disseminate a model of a rural internship program in an effort to attract nurses to rural communities. Run by a director, clinical coordinator, full-time secretary, and half-time typist, the program places BS/RN degree…

  10. 34 CFR 300.327 - Educational placements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Educational placements. 300.327 Section 300.327 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN WITH DISABILITIES Evaluations,...

  11. 5 CFR 359.702 - Placement rights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Placement rights. 359.702 Section 359.702 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REMOVAL FROM THE SENIOR... rights. (a) An appointee covered by this subpart is entitled to be placed in a vacant civil...

  12. Children's Language Institute Preschool Placement Test (CLIPPT).

    ERIC Educational Resources Information Center

    Quin, Paul E.; And Others

    The Children's Language Institute Preschool Placement Test (CLIPPT) identifies children, aged 2.6 to 4 years, with mild to moderate language/learning deficits, to determine which children would benefit from a language intervention preschool program. The test is presented in three sections: (1) the Informational Manual which provides theoretical…

  13. How Students View the Placement Office.

    ERIC Educational Resources Information Center

    Marion, Paul B.; And Others

    1983-01-01

    Surveyed 203 recent college graduates to determine what sources of information students use to find employment and how helpful these sources are. Results showed direct contact with the employer was the information source used most often, followed by family and friends, the placement office, and newspaper advertisement. (JAC)

  14. INTERACTIVE NAME PLACEMENT FOR PROVISIONAL MAPS.

    USGS Publications Warehouse

    Goldberg, Jeffrey L.; Miller, Thomas C.

    1983-01-01

    Computer generation and placement of map type has been refined into a production mode at Mid-Continent Mapping Center (MCMC) for USGS 1:24,000- and 1:25,000-scale Provisional maps. The map collar program is written in FORTRAN using batch processing that allows the program to work in the background.

  15. Advanced Placement: Model Policy Components. Policy Analysis

    ERIC Educational Resources Information Center

    Zinth, Jennifer

    2016-01-01

    Advanced Placement (AP), launched in 1955 by the College Board as a program to offer gifted high school students the opportunity to complete entry-level college coursework, has since expanded to encourage a broader array of students to tackle challenging content. This Education Commission of the State's Policy Analysis identifies key components of…

  16. Understanding the Role-Emerging Fieldwork Placement.

    ERIC Educational Resources Information Center

    Bossers, Ann M.; And Others

    1997-01-01

    Students' perceptions (n=11) of role-emerging placements as a learning experience in occupational therapy were explored using qualitative methods. Findings indicate that important learning occurs in the role-emerging experience, which provides opportunities for the development of students as professionals. (Author/JOW)

  17. Online Placement in First-Year Writing

    ERIC Educational Resources Information Center

    Peckham, Irvin

    2009-01-01

    This essay describes Louisiana State University's search for an alternative to available placement protocols. Under the leadership of Les Perelman at MIT, LSU collaborated with four universities to develop iMOAT, a program for administering online assessments of student writing. This essay focuses on LSU's On-line Challenge, which developed from…

  18. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  19. Photoelectron Spectroscopy in Advanced Placement Chemistry

    ERIC Educational Resources Information Center

    Benigna, James

    2014-01-01

    Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

  20. In Job-Placement Rates, Fuzzy Data

    ERIC Educational Resources Information Center

    Sandoval, Timothy

    2012-01-01

    As colleges and lawmakers seek better data about the employment success of graduates, a lack of standardized tracking makes much of the information unreliable. Many colleges release placement rates based on scant information: More than a third of colleges' reported rates in 2010 were based on responses from half of their graduates or fewer,…

  1. NEP advocates urged: set up needle exchange.

    PubMed

    1995-12-01

    The Point Defiance AIDS Projects, founded in 1988, is a successful needle exchange program (NEP) in Tacoma, WA. Program director David Purchase's approach to potential community resistance is based on the theory that it is better to seek forgiveness than to beg permission. Since its inception, the program has faced two legal battles that have been resolved in favor of Point Defiance. The Washington State Supreme Court ruled that exchange programs should be exempted from state paraphernalia laws. Point Defiance employs three full-time staff members experienced with the drug-using community to conduct on-site exchanges. HIV seroprevalence among injection drug users has remained below five percent over the last five years. PMID:11362933

  2. Transbronchial needle aspiration: where are we now?

    PubMed

    Xia, Yang; Wang, Ko-Pen

    2013-10-01

    Lung cancer, as the leading cause of cancer-related motility and mortality worldwide, usually ends up with poor prognosis, despite abundant progress of therapeutic approaches. Early diagnosis and staging is extremely critical and directly affects clinical managements and outcomes. Transbronchial needle aspiration (TBNA), serving as an effective tool, has been widely used for mediastinal and hilar lung cancer staging. Recent advance in bronchoscopy introduces ultrasound probe to regular bronchoscope, resulting in TBNA procedures real-time visualized. Here, we summarize the advantages and disadvantages of conventional TBNA (cTBNA) and ultrasound-guided TBNA by comparing the instruments, methodology as well as the anatomy. We believe these two techniques are not competitive but complementary, judging the indications of patients for different technique would be a raising issue applied for pulmonologists. PMID:24255782

  3. CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

    SciTech Connect

    Sotiropoulou, Evangelia; Stathochristopoulou, Irene; Stathopoulos, Konstantinos; Verigos, Kosmas; Salvaras, Nikolaos; Thanos, Loukas

    2010-06-15

    CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

  4. Adequate histologic sectioning of prostate needle biopsies.

    PubMed

    Bostwick, David G; Kahane, Hillel

    2013-08-01

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

  5. Needle-based confocal laser endomicroscopy

    PubMed Central

    Giovannini, Marc

    2015-01-01

    New applications of confocal laser endomicroscopy were developed as pCLE in the bile duct and nCLE for pancreatic cystic tumors, pancreatic masses and lymph nodes. The aim of this paper would be to give you an update in this new technology and to try to define its place in the diagnosis of cystic and solid pancreatic masses. The material used was a 19G EUS-needle in which the stylet was replaced by the Confocal mini-probe. The mini-probe (0.632 mm of diameter) is pre-loaded and screwed by a locking device in the EUS-Needle and guided endosonographically in the target. Regarding pancreatic cystic lesion, the presence of epithelial villous structures based on nCLE was associated with pancreatic cystic neoplasm (IPMN) (P = 0.004) and provided a sensitivity of 59%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. A superficial vascular network pattern visualized on nCLE was identified in serous cystadenomas. It corresponded on pathological specimen to a dense and subepithelial capillary vascularization. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of this sign for the diagnosis of SCA were 87%, 69%, 100%, 100%, and 82%, respectively. In pancreatic adenocarcinomas, nCLE found vascular leakage with irregular vessels with leakage of fluorescein into the tumor, large dark clumps which correspond to humps of malignant cells. These criteria correlate with the histological structure of those tumors which are characterized by tumoral glands, surrounded by fibrosis in case of fibrous stroma tumor. Neuroendocrine tumors showed a dense network of small vessels on a dark background, which fits with the histological structure based on cord of cells surrounded by vessels and by fibrosis. nCLE is feasible during a EUS examination; these preliminary results are very encouraging and may be used in the future in case of inconclusive EUS-FNA. PMID:26643694

  6. Placement techniques for the standard transistor array (Star)

    NASA Technical Reports Server (NTRS)

    Cox, G. W.; Carroll, B. D.

    1978-01-01

    Techniques for the placement of digital logic cells on STAR's (Standard Transistor Arrays) were developed. These techniques are designed to provide placement automation capabilities to low volume users with limited available processing power. A series of programs implementing the placement techniques was written and a number of test cases executed. Results of these test cases indicate that the methods achieve near optimum placements with respect to network routability.

  7. A New Scheme for Curved Needle Segmentation in Three-Dimensional Ultrasound Images

    PubMed Central

    Aboofazeli, Mohammad; Abolmaesumi, Purang; Mousavi, Parvin; Fichtinger, Gabor

    2010-01-01

    Ultrasound image guided needle insertion is the method of choice for a wide variety of medical diagnostic and therapeutic procedures. When flexible needles are inserted in soft tissue, these needles generally follow a curved path. Segmenting the trajectory of the needles in ultrasound images will facilitate guiding them within the tissue. In this paper, a novel algorithm for curved needle segmentation in three-dimensional (3D) ultrasound images is presented. The algorithm is based on the projection of a filtered 3D image onto a two-dimensional (2D) image. Detection of the needle in the resulting 2D image determines a surface on which the needle is located. The needle is then segmented on the surface. The proposed technique is able to detect needles without any previous assumption about the needle shape, or any a priori knowledge about the needle insertion axis line. PMID:20563242

  8. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  9. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  10. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  11. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  12. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  13. Brand Placement and Consumer Choice: An in-Store Experiment

    ERIC Educational Resources Information Center

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior.…

  14. BRAND PLACEMENT AND CONSUMER CHOICE: AN IN-STORE EXPERIMENT

    PubMed Central

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior. PMID:20190939

  15. Mathematics Placement Test: Typical Results with Unexpected Outcomes

    ERIC Educational Resources Information Center

    Ingalls, Victoria

    2011-01-01

    Based on the results of a prior case-study analysis of mathematics placement at one university, the mathematics department developed and piloted a mathematics placement test. This article describes the implementation process for a mathematics placement test and further analyzes the test results for the pilot group. As an unexpected result, the…

  16. 20 CFR 638.409 - Placement and job development.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Placement and job development. 638.409 Section 638.409 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR JOB CORPS... Placements in the Job Corps § 638.409 Placement and job development. The overall objective of all Job...

  17. 20 CFR 638.409 - Placement and job development.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Placement and job development. 638.409 Section 638.409 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR JOB CORPS... Placements in the Job Corps § 638.409 Placement and job development. The overall objective of all Job...

  18. Brevard District Plan for Placement and Follow-Up.

    ERIC Educational Resources Information Center

    Thomas, Olive W.

    The Brevard District Plan for placement and follow-up is intended for all secondary students, including dropouts, disadvantaged, adult students, and graduates. The areas of placement may be in gainful employment, educational institutions, or a combination of both. The plan specifies procedures for implementing placement and stipulates the type of…

  19. Modeling Cryotherapy Ice Ball Dimensions and Isotherms in a Novel Gel-based Model to Determine Optimal Cryo-needle Configurations and Settings for Potential Use in Clinical Practice

    PubMed Central

    Shah, Taimur T.; Arbel, Uri; Foss, Sonja; Zachman, Andrew; Rodney, Simon; Ahmed, Hashim U.; Arya, Manit

    2016-01-01

    Objective To gain a better understanding of ice ball dimensions and temperature isotherms relevant for cell kill when using combinations of cryo-needles we set out to answer 4 questions: (1) what type of cryo-needle? (2) how many needles? (3) best spatial configuration? and (4) correct duty cycle percentage? Methods We conducted laboratory experiments to monitor ice ball dimensions and create multi-needle planar isotherm maps for 17G and 10G cryo-needles using a novel multi-needle thermocouple fixture within gel at body temperature. We tested configurations of 1-4 cryo-needles at duty cycles of 20%-100% with 1-2.5 cm spacing. Results Analysis of various combinations shows that a central core of ≤−40°C develops at a distance of ~1 cm around the cryo-needles. Temperature increases linearly from this point to the ice ball leading edge (0°C), which is a further ≈1 cm away. Thus, the −40°C isotherm is approximately 1 cm inside the leading edge of the ice ball. The optimum distance between cryo-needles was 1.5-2 cm, at duty cycle settings of 70%-100%. At distances further apart or with lower duty cycle settings, ice balls either had a central core >−40°C or had an hourglass shape. Conclusion In answer to questions 1-3, tumor length, diameter, and shape will ultimately determine the number of needles and their configuration. However, we propose a conservative distance for cryo-needle placement between 1 and 1.5 cm should be adopted for clinical practice. In answer to question 4, using low duty cycle settings runs the risk of incomplete −40°C isotherm coverage of the tumor, and thus in routine practice we suggest that settings of 70%-100% are most appropriate. PMID:26902833

  20. Development of plasma needle to be used for biomedical applications

    NASA Astrophysics Data System (ADS)

    Bora, B.; Jain, J.; Inestrosa-Izurieta, M. J.; Avaria, G.; Moreno, J.; Pavez, C.; Marcelain, K.; Armisen, R.; Soto, L.

    2016-05-01

    Plasma needle is a novel design of a plasma source at atmospheric pressure to achieve a non-thermal plasma jet. The advantage of the plasma needle is that it can be operated in open air, outside a vessel. The plasma that is generated with the plasma needle is small (about one millimetre) and non-thermal, the temperature of the neutral particles and ions is in about room temperature and suitably can interact with living biological cell without damaging the cell. In this work, we report the development of a plasma needle, which is operated by a dc power source and produced a stable plasma jet on water surface. Argon gas is used to operate the plasma needle. The preliminary electrical diagnostics of the plasma needle shows that the discharge is filamentary in nature. For diagnostic of the plasma jet produced by the developed plasma needle, the produced plasma jet is directed to water surface and characterization are carried out by means of electrical discharge characteristics and optical emission spectroscopy. In this work, preliminary results of the diagnostic will be presented.