Recurrent clot anuria following laparoscopic pyeloplasty in a solitary functioning kidney: managing with double guide wire technique

PubMed Central

Kumar, Santosh; Singh, Shivanshu; Parmar, Kalpesh Mahesh; Garg, Nitin

2014-01-01

Clot anuria in a solitary functioning kidney is an emergency situation. Haematuria with clot anuria in an early postoperative period represents a challenge, as treatment options are limited. Manipulation of the anastomotic site may lead to anastomotic disruption and urinoma while use of thrombolytic therapy poses the danger of increasing haematuria. We report a case of anuria due to clot retention in the upper tract following laparoscopic dismembered pyeloplasty in a solitary functioning kidney, managed successfully with double guide wire technique. PMID:25540210

[Current strategy in PCI for CTO].

PubMed

Asakura, Yasushi

2011-02-01

Recently, CTO PCI has come into wide use all over the world and it has been standardized. The 1st step is an antegrade approach using single wire. The 2nd strategy would be parallel wire technique. And the next would be a retrograde approach. In this method, retrograde wiring with Corsair is done at first. If it is successful, externalization is established using 300 cm wire, and this system is able to provide strong back-up support. If it fails, reverse CART technique is the next step. IVUS guided wiring is a last resort. The 2nd wire is manipulated with IVUS guidance. Now, initial success rate is more than 90% with these methods.

Emergency cricothyrotomy-a comparative study of different techniques in human cadavers.

PubMed

Schober, Patrick; Hegemann, Martina C; Schwarte, Lothar A; Loer, Stephan A; Noetges, Peter

2009-02-01

Emergency cricothyrotomy is the final lifesaving option in "cannot intubate-cannot ventilate" situations. Fast, efficient and safe management is indispensable to reestablish oxygenation, thus the quickest, most reliable and safest technique should be used. Several cricothyrotomy techniques exist, which can be grouped into two categories: anatomical-surgical and puncture. We studied success rate, tracheal tube insertion time and complications of different techniques, including a novel cricothyrotomy scissors technique in human cadavers. Sixty-three inexperienced health care providers were randomly assigned to apply either an anatomical-surgical technique (standard surgical technique, n=18; novel cricothyrotomy scissors technique, n=14) or a puncture technique (catheter-over-needle technique, n=17; wire-guided technique, n=14). Airway access was almost always successful with the anatomical-surgical techniques (success rate in standard surgical group 94%, scissors group 100%). In contrast, the success rate was smaller (p<0.05) with the puncture techniques (catheter-over-needle group 82%, wire-guided technique 71%). Tracheal tube insertion time was faster overall (p<0.05) with anatomical-surgical techniques (standard surgical 78s [54-135], novel cricothyrotomy scissors technique 60s [42-82]; median [IQR]) than with puncture techniques (catheter-over-needle technique 74s [48-145], wire-guided technique 135s [116-307]). We observed fewer complications with anatomical-surgical techniques than with puncture techniques (p<0.001). In inexperienced health care personnel, anatomical-surgical techniques showed a higher success rate, a faster tracheal tube insertion time and a lower complication rate compared with puncture techniques, suggesting that they may be the techniques of choice in emergencies.

A new adjustable parallel drill guide for internal fixation of femoral neck fracture: a developmental and experimental study.

PubMed

Yuenyongviwat, Varah; Tuntarattanapong, Pakjai; Tangtrakulwanich, Boonsin

2016-01-11

Internal fixation is one treatment for femoral neck fracture. Some devices and techniques reported improved accuracy and decreased fluoroscopic time. However, these are not widely used nowadays due to the lack of available special instruments and techniques. To improve the surgical procedure, the authors designed a new adjustable drill guide and tested the efficacy of the device. The authors developed a new adjustable drill guide for cannulated screw guide wire insertion for multiple screw fixation. Eight orthopaedic surgeons performed the experimental study to evaluate the efficacy of this device. Each surgeon performed guide wire insertion for multiple screw fixation in six synthetic femurs: three times with the new device and three times with the conventional technique. The fluoroscopic time, operative time and surgeon satisfaction were evaluated. In the operations with the new adjustable drill guide, the fluoroscopic and operative times were significantly lower than the operations with the conventional technique (p < 0.05). The mean score for the level of satisfaction of this device was also statistically significantly better (p = 0.02) than the conventional technique. The fluoroscopic and operative times with the new adjustable drill guide were reduced for multiple screw fixation of femoral neck fracture and the satisfaction of the surgeons was good.

Validation of a technique for accurate fine-wire electrode placement into posterior gluteus medius using real-time ultrasound guidance.

PubMed

Hodges, P W; Kippers, V; Richardson, C A

1997-01-01

Fine-wire electromyography is primarily utilised for the recording of activity of the deep musculature, however, due to the location of these muscles, accurate electrode placement is difficult. Real-time ultrasound imaging (RTUI) of muscle tissue has been used for the guidance of the needle insertion for the placement of electrodes into the muscles of the abdominal wall. The validity of RTUI guidance of needle insertion into the deep muscles has not been determined. A cadaveric study was conducted to evaluate the accuracy with which RTUI can be used to guide fine-wire electrode placement using the posterior fibres of gluteus medius (PGM) as an example. Pilot studies revealed that the ultrasound resolution of cadaveric tissue is markedly reduced making it impossible to directly evaluate the technique, therefore, three studies were conducted. An initial study involved the demarcation of the anatomical boundaries of PGM using RTUI to define a technique based on an anatomical landmark that was consisent with the in vivo RTUI guided needle placement technique. This anatomical landmark was then used as the guide for the cadaveric needle insertion. Once the needle was positioned 0.05 ml of dye was introduced and the specimen dissected. The dye was accurately placed in PGM in 100% of the specimens. Finally, fine-wire electrodes were inserted into the PGM of five volunteers and manoeuvres performed indicating the accuracy of placement. This study supports the use of ultrasound imaging for the accurate guidance of needle insertion for fine-wire and needle EMG electrodes.

Electrochemical Fabrication of Metallic Quantum Wires

ERIC Educational Resources Information Center

Tao, Nongjian

2005-01-01

The fabrication of metallic quantum wires using simple electrochemical techniques is described. The conductance of the system can be readily measured that allows one to constantly monitor the conductance during fabrication and use conductance quantization as a signature to guide the fabrication.

JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricci, Carmelo; Ceccherini, Claudio, E-mail: claudiocec@hotmail.it; Leonini, Sara

An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

Coronary and peripheral stenting in aorto-ostial protruding stents: The balloon assisted access to protruding stent technique.

PubMed

Helmy, Tarek A; Sanchez, Carlos E; Bailey, Steven R

2016-03-01

Treatment of aorto-ostial in-stent restenosis lesions represents a challenge for interventional cardiologists. Excessive protrusion of the stent into the aorta may lead to multiple technical problems, such as difficult catheter reengagement of the vessel ostium or inability to re-wire through the stent lumen in repeat interventions. We describe a balloon assisted access to protruding stent technique in cases where conventional coaxial engagement of an aorto-ostial protruding stent with the guide catheter or passage of the guide wire through the true lumen is not feasible. This technique is applicable both in coronary and peripheral arteries. © 2015 Wiley Periodicals, Inc.

Application of Ultrasonic Guided Waves for Evaluating Aging Wire Insulation

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2005-01-01

Aging wiring has become a critical issue to the aerospace and aircraft industries due to Shuttle and aircraft incidents. The problem is that over time the insulation on wire becomes brittle and cracks. This exposes the underlying conductive wire to the potential for short circuits and fire. Popular methods of monitoring aging wire problems focuses on applying electrical sensing techniques that are sensitive to the conductor's condition, but not very sensitive to the wire insulation's condition. Measurement of wire insulation stiffness and ultrasonic properties by ultrasonic guided waves is being examined. Experimental measurements showed that the lowest order extensional mode could be sensitive to stiffness changes in the wire insulation. To test this theory conventional wire samples were heat damaged in an oven, in a range of heating conditions. The samples were 12, 16, and 20 gauge and the heat damage introduced material changes in the wire insulation that made the originally flexible insulation brittle and darker in color. Results showed that extensional mode phase velocity increased for the samples that were exposed to heat for longer duration.

Preoperative computed tomography-guided percutaneous hookwire localization of metallic marker clips in the breast with a radial approach: initial experience.

PubMed

Uematsu, T; Kasami, M; Uchida, Y; Sanuki, J; Kimura, K; Tanaka, K; Takahashi, K

2007-06-01

Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

A comparison of line enhancement techniques: applications to guide-wire detection and respiratory motion tracking

NASA Astrophysics Data System (ADS)

Bismuth, Vincent; Vancamberg, Laurence; Gorges, Sébastien

2009-02-01

During interventional radiology procedures, guide-wires are usually inserted into the patients vascular tree for diagnosis or healing purpose. These procedures are monitored with an Xray interventional system providing images of the interventional devices navigating through the patient's body. The automatic detection of such tools by image processing means has gained maturity over the past years and enables applications ranging from image enhancement to multimodal image fusion. Sophisticated detection methods are emerging, which rely on a variety of device enhancement techniques. In this article we reviewed and classified these techniques into three families. We chose a state of the art approach in each of them and built a rigorous framework to compare their detection capability and their computational complexity. Through simulations and the intensive use of ROC curves we demonstrated that the Hessian based methods are the most robust to strong curvature of the devices and that the family of rotated filters technique is the most suited for detecting low CNR and low curvature devices. The steerable filter approach demonstrated less interesting detection capabilities and appears to be the most expensive one to compute. Finally we demonstrated the interest of automatic guide-wire detection on a clinical topic: the compensation of respiratory motion in multimodal image fusion.

Radiofrequency wire for the recanalization of central vein occlusions that have failed conventional endovascular techniques.

PubMed

Guimaraes, Marcelo; Schonholz, Claudio; Hannegan, Christopher; Anderson, Michael Bret; Shi, June; Selby, Bayne

2012-08-01

To report the technique and acute technical results associated with the PowerWire Radiofrequency (RF) Guidewire used to recanalize central vein occlusions (CVOs) after the failure of conventional endovascular techniques. A retrospective study was conducted from January 2008 to December 2011, which identified all patients with CVOs who underwent treatment with a novel RF guide wire. Forty-two symptomatic patients (with swollen arm or superior vena cava [SVC] syndrome) underwent RF wire recanalization of 43 CVOs, which were then implanted with stents. The distribution of CVOs in central veins was as follows: six subclavian, 29 brachiocephalic, and eight SVC. All patients had a history of central venous catheter placement. Patients were monitored with regular clinical evaluations and central venography after treatment. All 42 patients had successful recanalization of CVOs facilitated by the RF wire technique. There was one complication, which was not directly related to the RF wire: one case of cardiac tamponade attributed to balloon angioplasty after stent placement. Forty of 42 patients (95.2%) had patent stents and were asymptomatic at 6 and 9 months after treatment. The present results suggest that the RF wire technique is a safe and efficient alternative in the recanalization of symptomatic and chronic CVOs when conventional endovascular techniques have failed. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Retrograde intubation: an alternative way for the management of difficult airway.

PubMed

Lama, P; Shrestha, B R

2008-01-01

Inserting a retrograde wire into the pharynx through a cricothyroid puncture can facilitate tracheal intubation in difficult situations where either a flexible fiber-optic bronchoscope or an expert user of such a device is not available. Even in cases when fibropric can not be negotiated for the purpose, this method has been claimed to be useful to manage the airway. Some mouth opening is essential for the oral or nasal retrieval of the wire from the pharynx. Here, a case of post mandibular reconstructed wound infection required surgical debridement and plate removal from reconstructed lower mandible under general anesthesia. We retrieved the guide wire passed through a cricothyroid puncture and subsequently accomplished wire-guided oro-tracheal intubation. In the absence of a flexible fiber-optic bronchoscope, this technique is a very useful aid to intubate patients with limited mouth opening.

Percutaneous Treatment of Coronary Chronic Total Occlusion Part 2: Technical Approach

PubMed Central

Galassi, Alfredo; Grantham, Aaron; Kandzari, David; Lombardi, William; Moussa, Issam; Thompson, Craig; Werner, Gerald; Chambers, Charles

2014-01-01

Dual injection is recommended for nearly all chronic total occlusion (CTO) percutaneous coronary intervention (PCI) to determine the optimal crossing strategy and guide wire advancement into the distal true lumen. Strategies that provide enhanced guide catheter support (such as long sheaths, large-bore guiding catheters, use of guide catheter extensions, and anchor techniques) are important for maximising the success rate and efficiency of CTO PCI. Use of a microcatheter or over-the-wire balloon is strongly recommended in CTO PCI for enhancing the penetrating power of the guidewire, enabling change in tip shape and allowing guidewire change (stiff CTO guidewires are not optimal for crossing non-occluded coronary segments). Adherence to a procedural strategy that standardises CTO technique and facilitates procedural success is recommended. Such a strategy would permit stepwise decision-making for antegrade and retrograde methods; inform guidewire selection; and incorporate alternative approaches for instances of initial failure. Given the paucity of long-term outcomes with use of novel crossing techniques (antegrade dissection/re-entry and retrograde), antegrade wire escalation is the preferred CTO crossing technique, if technically feasible. Using measures to minimise radiation exposure (including but not limited to use of 7.5 frames per second fluoroscopy and use of low magnification) and contrast administration is recommended. CTO PCI is best performed at centres with dedicated CTO PCI experience and expertise. Use of crossing difficulty prediction tools, such as the J-CTO score, can facilitate the selection of cases with a high likelihood of quick crossing that can be attempted at less experienced centres. PMID:29588803

Minimally Invasive Calcaneal Displacement Osteotomy Site Using a Reference Kirschner Wire: A Technique Tip.

PubMed

Lee, Moses; Guyton, Gregory P; Zahoor, Talal; Schon, Lew C

2016-01-01

As a standard open approach, the lateral oblique incision has been widely used for calcaneal displacement osteotomy. However, just as with other orthopedic procedures that use an open approach, complications, including wound healing problems and neurovascular injury in the heel, have been reported. To help avoid these limitations, a percutaneous technique using a Shannon burr for calcaneal displacement osteotomy was introduced. However, relying on a free-hand technique without direct visualization at the osteotomy site has been a major obstacle for this technique. To address this problem, we developed a technical tip using a reference Kirschner wire. A reference Kirschner wire technique provides a reliable and accurate guide for minimally invasive calcaneal displacement osteotomy. Also, the technique should be easy to learn for surgeons new to the procedure. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Strategies for prevention of iatrogenic inferior vena cava filter entrapment and dislodgement during central venous catheter placement.

PubMed

Wu, Alex; Helo, Naseem; Moon, Eunice; Tam, Matthew; Kapoor, Baljendra; Wang, Weiping

2014-01-01

Iatrogenic migration of inferior vena cava (IVC) filters is a potentially life-threatening complication that can arise during blind insertion of central venous catheters when the guide wire becomes entangled with the filter. In this study, we reviewed the occurrence of iatrogenic migration of IVC filters in the literature and assessed methods for preventing this complication. A literature search was conducted to identify reports of filter/wire entrapment and subsequent IVC filter migration. Clinical outcomes and complications were identified. A total of 38 cases of filter/wire entrapment were identified. All of these cases involved J-tip guide wires. Filters included 23 Greenfield filters, 14 VenaTech filters, and one TrapEase filter. In 18 cases of filter/wire entrapment, there was migration of the filter to the heart and other central venous structures. Retrieval of the migrated filter was successful in only four of the 18 cases, and all of these cases were complicated by strut fracture and distant embolization of fragments. One patient required resuscitation during retrieval. Successful disengagement was possible in 20 cases without filter migration. Iatrogenic migration of an IVC filter is an uncommon complication related to wire/filter entrapment. This complication can be prevented with knowledge of the patient's history, use of proper techniques when placing a central venous catheter, identification of wire entrapment at an early stage, and use of an appropriate technique to disengage an entrapped wire. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

21 CFR 870.1330 - Catheter guide wire.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Catheter guide wire. 870.1330 Section 870.1330...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1330 Catheter guide wire. (a) Identification. A catheter guide wire is a coiled wire that is designed to fit inside a...

21 CFR 870.1330 - Catheter guide wire.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Catheter guide wire. 870.1330 Section 870.1330...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1330 Catheter guide wire. (a) Identification. A catheter guide wire is a coiled wire that is designed to fit inside a...

Dual wire welding torch and method

DOEpatents

Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

2009-04-28

A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

Video-assisted thoracoscopic surgery for pulmonary nodules after computed tomography-guided marking with a spiral wire.

PubMed

Eichfeld, Uwe; Dietrich, Arne; Ott, Rudolph; Kloeppel, Rainer

2005-01-01

Peripheral pulmonary nodules are preferably removed by minimally invasive techniques, such as video-assisted thoracoscopic (VATS) surgery. These nodules should be marked preoperatively for better intraoperative detection and removal. Twenty-two cases with a single pulmonary nodule requiring surgical removal for histologic examination were included in a prospective study. Guided by computed tomography, nodules were marked preoperatively using a laser marker system and fixed with a spiral wire. The marked nodules were removed by VATS surgery immediately after the marking. The marking wire was placed in all 22 patients without any complications. The marked nodule was completely removed by VATS surgery in 19 patients. Conversion to thoracotomy was necessary in 3 patients, twice because of thoracoscopy-related problems and once because of a marking failure. The average times for the marking procedure and operation were 24 minutes and 32 minutes, respectively. This new method of computed tomography-guided nodule marking with a spiral wire and subsequent VATS surgery is very efficient in terms of localization and stable fixation of subpleural pulmonary nodules.

Internal wire guide for GTAW welding

NASA Technical Reports Server (NTRS)

Morgan, Gene E. (Inventor); Dyer, Gerald E. (Inventor)

1989-01-01

A welding torch for gas tungsten arc welding apparatus has a filler metal wire guide positioned within the torch, and within the shielding gas nozzle. The wire guide is adjacent to the tungsten electrode and has a ceramic liner through which the wire is fed. This reduces the size of the torch and eliminates the outside clearance problems that exit with external wire guides. Additionally, since the wire is always within the shielding gas, oxidizing of the wire is eliminated.

Multicenter comparative trial of the V-scope system for therapeutic ERCP.

PubMed

Joyce, A M; Ahmad, N A; Beilstein, M C; Kochman, M L; Long, W B; Baron, T; Sherman, S; Fogel, E; Lehman, G A; McHenry, L; Watkins, J; Ginsberg, G G

2006-07-01

A new duodenoscope (the V-scope), with a modified elevator used in combination with a dedicated short guide wire, constitutes the V-system. This system is intended to allow fixation of the guide wire at the elevator lever, thereby enhancing the speed and reliability of accessory exchange over a guide wire during ERCP. The aim of this study was to evaluate the extent to which the V-system provides improved efficiency in comparison with conventional duodenoscope and guide wire combinations. This was an industry-sponsored multicenter randomized trial. Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) procedures in which treatment was anticipated were randomly assigned to the V-system or to a conventional duodenoscope and accessories used routinely in each center. The parameters recorded included the total case time, fluoroscopy time, catheter/guide wire exchange time, guide wire repositioning, loss of guide wire access, and success or failure of guide wire fixation when using the V-system. Fifty patients were included, 22 in the conventional group and 28 in the V-system group. A total of 135 exchanges were carried out. The patients had up to six exchanges. The median exchange time was 19.4 s with the V-system and 31.7 s with the conventional systems ( P < 0.001). Guide wire repositioning was required less often in the V-system group ( P = 0.0005). The V-system effectively locked the guide wire in 63 of 71 exchanges (89 %). Loss of guide wire access occurred in two patients in the conventional group and four in the V-system group, attributable to failure to lock the guide wire early during the experience (no significant differences). The V-system can effectively secure the guide wire during accessory exchange in ERCP and reduces the time required to exchange accessories. This may enhance overall efficiency during ERCP.

Extra Luminal Entrapment of Guide Wire; A Rare Complication of Central Venous Catheter Placement in Right Internal Jugular Vein.

PubMed

Ansari, Md Abu Masud; Kumar, Naveen; Kumar, Shailesh; Kumari, Sarita

2016-10-01

Central venous Catheterization (CVC) is a commonly performed procedure for venous access. It is associated with several complications. We report a rare case of extra luminal entrapment of guide wire during CVC placement in right jugular vein. We report a case of 28 years old female patient presented in our emergency with history of entrapped guide wire in right side of neck during CVC. X-ray showed coiling of guide wire in neck. CT Angiography showed guide wire coursing in between common carotid artery and internal jugular vein (IJV), closely abutting the wall of both vessels. The guide wire was coiled with end coursing behind the esophageal wall. Guide wire was removed under fluoroscopic guide manipulation under local anesthesia. We want to emphasize that even though CVC placement is common and simple procedure, serious complication can occur in hands of untrained operator. The procedure should be performed under supervision, if done by trainee. Force should never be applied to advance the guide wire if resistance is encountered.

PPM-based System for Guided Waves Communication Through Corrosion Resistant Multi-wire Cables

NASA Astrophysics Data System (ADS)

Trane, G.; Mijarez, R.; Guevara, R.; Pascacio, D.

Novel wireless communication channels are a necessity in applications surrounded by harsh environments, for instance down-hole oil reservoirs. Traditional radio frequency (RF) communication schemes are not capable of transmitting signals through metal enclosures surrounded by corrosive gases and liquids. As an alternative to RF, a pulse position modulation (PPM) guided waves communication system has been developed and evaluated using a corrosion resistant 4H18 multi-wire cable, commonly used to descend electronic gauges in down-hole oil applications, as the communication medium. The system consists of a transmitter and a receiver that utilizes a PZT crystal, for electrical/mechanical coupling, attached to each extreme of the multi-wire cable. The modulator is based on a microcontroller, which transmits60 kHz guided wave pulses, and the demodulator is based on a commercial digital signal processor (DSP) module that performs real time DSP algorithms. Experimental results are presented, which were obtained using a 1m corrosion resistant 4H18multi-wire cable, commonly used with downhole electronic gauges in the oil sector. Although there was significant dispersion and multiple mode excitations of the transmitted guided wave energy pulses, the results show that data rates on the order of 500 bits per second are readily available employing PPM and simple communications techniques.

Qureshi-5 Catheter for Complex Supra- and Abdominal-Aortic Catheterization

PubMed Central

Qureshi, Adnan I.; Xiao, WeiGang; Liu, HongLiang

2015-01-01

Background The use of previously described catheter technique was expanded to complex supra- and abdominal- aortic catheterizations. Methods A new (Qureshi 5) catheter with curved shape at the distal end that has two lumens was used. One of lumens can accommodate a 0.035-inch guide wire and the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen. The manipulation and engagement of the curved distal end catheter was facilitated by rotation and movement of the J-shaped 0.018-inch guide wire extended coaxial and beyond the distal end of catheter. Subsequently, either contrast was injected or a 0.035-inch guide wire advanced into the target artery. Results The catheters were used in one patient to perform diagnostic cerebral and abdominal angiography through a 6F introducer sheath placed in the right common femoral artery. The catheterization was complex because of severe tortuosity of arch and descending aorta secondary to kyphosis. The left and right internal carotid arteries and left and right vertebral arteries, left renal artery, and superior mesenteric artery were catheterized in patient (fluoroscopy time 19:46 min). No complications were observed in the patient. Conclusions The Qureshi-5 catheter was successful in complex supra- and abdominal-aortic catheterizations. PMID:26600925

Qureshi-5 Catheter for Complex Supra- and Abdominal-Aortic Catheterization.

PubMed

Qureshi, Adnan I; Xiao, WeiGang; Liu, HongLiang

2015-10-01

The use of previously described catheter technique was expanded to complex supra- and abdominal- aortic catheterizations. A new (Qureshi 5) catheter with curved shape at the distal end that has two lumens was used. One of lumens can accommodate a 0.035-inch guide wire and the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen. The manipulation and engagement of the curved distal end catheter was facilitated by rotation and movement of the J-shaped 0.018-inch guide wire extended coaxial and beyond the distal end of catheter. Subsequently, either contrast was injected or a 0.035-inch guide wire advanced into the target artery. The catheters were used in one patient to perform diagnostic cerebral and abdominal angiography through a 6F introducer sheath placed in the right common femoral artery. The catheterization was complex because of severe tortuosity of arch and descending aorta secondary to kyphosis. The left and right internal carotid arteries and left and right vertebral arteries, left renal artery, and superior mesenteric artery were catheterized in patient (fluoroscopy time 19:46 min). No complications were observed in the patient. The Qureshi-5 catheter was successful in complex supra- and abdominal-aortic catheterizations.

Operation and force analysis of the guide wire in a minimally invasive vascular interventional surgery robot system

NASA Astrophysics Data System (ADS)

Yang, Xue; Wang, Hongbo; Sun, Li; Yu, Hongnian

2015-03-01

To develop a robot system for minimally invasive surgery is significant, however the existing minimally invasive surgery robots are not applicable in practical operations, due to their limited functioning and weaker perception. A novel wire feeder is proposed for minimally invasive vascular interventional surgery. It is used for assisting surgeons in delivering a guide wire, balloon and stenting into a specific lesion location. By contrasting those existing wire feeders, the motion methods for delivering and rotating the guide wire in blood vessel are described, and their mechanical realization is presented. A new resistant force detecting method is given in details. The change of the resistance force can help the operator feel the block or embolism existing in front of the guide wire. The driving torque for rotating the guide wire is developed at different positions. Using the CT reconstruction image and extracted vessel paths, the path equation of the blood vessel is obtained. Combining the shapes of the guide wire outside the blood vessel, the whole bending equation of the guide wire is obtained. That is a risk criterion in the delivering process. This process can make operations safer and man-machine interaction more reliable. A novel surgery robot for feeding guide wire is designed, and a risk criterion for the system is given.

MR-compatible polyetheretherketone-based guide wire assisting MR-guided stenting of iliac and supraaortic arteries in swine: feasibility study.

PubMed

Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M; Borm, Paul J A; Jacob, Augustinus L; Bilecen, Deniz

2009-01-01

The purpose of this study was to demonstrate first magnetic resonance (MR)-guided stenting of iliac and supraaortic arteries using a polyetheretherketone-based (PEEK) MR-compatible guide wire. In vitro and animal experiments were performed in a short magnet wide-bore scanner (1.5 Tesla, Espree, Siemens Healthcare, Erlangen, Germany). For all experiments, a 0.035'' MR-compatible guide wire prototoype was used. This wire had a compound core of PEEK with reinforcing fibres, a soft and atraumatic tip and a hydrophilic coating. For its passive visualization, paramagnetic markings were attached. All experiments were performed through a vascular introducer sheath under MR-guidance. In vitro repetitive selective over the wire catheterizations of either the right carotid artery and the left subclavian artery were performed. In vivo, selective catheterization and over-the-wire stenting of the brachiocephalic trunk and the left subclavian artery were performed. The common iliac arteries were catheterized retrogradely (left) and cross-over (right). Angioplasty and stenting were performed over-the-wire. All procedures were successful. Visibility of the PEEK-based guide-wire was rated good in vitro and acceptable in vivo. Guide wire pushability and endovascular device support were good. The PEEK-based MR-compatible guide wire is well visible and usable under MR-guidance. It supports over-the-wire treatment of iliac arteries and supraaortic arteries.

Use of Flexible Cystoscopy to Insert a Foley Catheter over a Guide Wire in Spinal Cord Injury Patients: Special Precautions to be Observed.

PubMed

Vaidyanathan, Subramanian; Soni, Bakul; Singh, Gurpreet; Hughes, Peter; Oo, Tun

2011-01-01

When urethral catheterisation is difficult or impossible in spinal cord injury patients, flexible cystoscopy and urethral catheterisation over a guide wire can be performed on the bedside, thus obviating the need for emergency suprapubic cystostomy. Spinal cord injury patients, who undergo flexible cystoscopy and urethral catheterisation over a guide wire, may develop potentially serious complications. (1) Persons with lesion above T-6 are susceptible to develop autonomic dysreflexia during cystoscopy and urethral catheterisation over a guide wire; nifedipine 5-10 milligrams may be administered sublingually just prior to the procedure to prevent autonomic dysreflexia. (2) Spinal cord injury patients are at increased risk for getting urine infections as compared to able-bodied individuals. Therefore, antibiotics should be given to patients who get haematuria or urethral bleeding following urethral catheterisation over a guide wire. (3) Some spinal cord injury patients may have a small capacity bladder; in these patients, the guide wire, which is introduced into the urinary bladder, may fold upon itself with the tip of guide wire entering the urethra. If this complication is not recognised and a catheter is inserted over the guide wire, the Foley catheter will then be misplaced in urethra despite using cystoscopy and guide wire.

Use of Flexible Cystoscopy to Insert a Foley Catheter over a Guide Wire in Spinal Cord Injury Patients: Special Precautions to be Observed

PubMed Central

Vaidyanathan, Subramanian; Soni, Bakul; Singh, Gurpreet; Hughes, Peter; Oo, Tun

2011-01-01

When urethral catheterisation is difficult or impossible in spinal cord injury patients, flexible cystoscopy and urethral catheterisation over a guide wire can be performed on the bedside, thus obviating the need for emergency suprapubic cystostomy. Spinal cord injury patients, who undergo flexible cystoscopy and urethral catheterisation over a guide wire, may develop potentially serious complications. (1) Persons with lesion above T-6 are susceptible to develop autonomic dysreflexia during cystoscopy and urethral catheterisation over a guide wire; nifedipine 5–10 milligrams may be administered sublingually just prior to the procedure to prevent autonomic dysreflexia. (2) Spinal cord injury patients are at increased risk for getting urine infections as compared to able-bodied individuals. Therefore, antibiotics should be given to patients who get haematuria or urethral bleeding following urethral catheterisation over a guide wire. (3) Some spinal cord injury patients may have a small capacity bladder; in these patients, the guide wire, which is introduced into the urinary bladder, may fold upon itself with the tip of guide wire entering the urethra. If this complication is not recognised and a catheter is inserted over the guide wire, the Foley catheter will then be misplaced in urethra despite using cystoscopy and guide wire. PMID:22110492

Ultrasonic Guided Waves for Aging Wire Insulation Assessment

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2001-01-01

Environmentally aged wire insulation can become brittle and crack and thus expose the underlying conductive wire to the potential for short circuits and fire. The feasibility of using ultrasonic guided waves to measure insulation condition was examined. First a simple model to study guided wave propagation in a bare and thin plastic coated wire was examined and then some aviation grade wire samples that had been heat-damaged. Initial measurements indicate that ultrasonic guided wave velocity can be used to monitor insulation stiffness.

The Wire-Grasping Method as a New Technique for Forceps Biopsy of Biliary Strictures: A Prospective Randomized Controlled Study of Effectiveness.

PubMed

Yamashita, Yasunobu; Ueda, Kazuki; Kawaji, Yuki; Tamura, Takashi; Itonaga, Masahiro; Yoshida, Takeichi; Maeda, Hiroki; Magari, Hirohito; Maekita, Takao; Iguchi, Mikitaka; Tamai, Hideyuki; Ichinose, Masao; Kato, Jun

2016-07-15

Transpapillary forceps biopsy is an effective diagnostic technique in patients with biliary stricture. This prospective study aimed to determine the usefulness of the wire-grasping method as a new technique for forceps biopsy. Consecutive patients with biliary stricture or irregularities of the bile duct wall were randomly allocated to either the direct or wire-grasping method group. In the wiregrasping method, forceps in the duodenum grasps a guidewire placed into the bile duct beforehand, and then, the forceps are pushed through the papilla without endoscopic sphincterotomy. In the direct method, forceps are directly pushed into the bile duct alongside a guide-wire. The primary endpoint was the success rate of obtaining specimens suitable for adequate pathological examination. In total, 32 patients were enrolled, and 28 (14 in each group) were eligible for analysis. The success rate was significantly higher using the wire-grasping method than the direct method (100% vs 50%, p=0.016). Sensitivity and accuracy for the diagnosis of cancer were comparable in patients with the successful procurement of biopsy specimens between the two methods (91% vs 83% and 93% vs 86%, respectively). The wire-grasping method is useful for diagnosing patients with biliary stricture or irregularities of the bile duct wall.

New Technique for the Preservation of the Left Common Carotid Artery in Zone 2a Endovascular Repair of Thoracic Aortic Aneurysm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Juszkat, Robert, E-mail: radiologiamim@wp.pl; Kulesza, Jerzy; Zarzecka, Anna

2011-02-15

To describe a technique for the preservation of the left common carotid artery (CCA) in zone 2 endovascular repair of thoracic aortic aneurysm. This technique involves the placement of a guide wire into the left CCA via the right brachial artery before stent graft deployment to enable precise visualization and protection of the left CCA during the whole procedure. Of the 107 patients with thoracic endovascular aortic repair in our study, 32 (30%) had the left subclavian artery intentionally covered (landing zone 2). Eight (25%) of those 32 had landing zone 2a-the segment distally the origin of the left CCA,more » halfway between the origin of the left CCA and the left subclavian artery. In all patients, a guide wire was positioned into the left CCA via the right brachial artery before stent graft deployment. It is a retrospective study in design. In seven patients, stent grafts were positioned precisely. In the remaining patient, the positioning was imprecise; the origin of the left CCA was partially covered by the graft. A stent was implanted into the left CCA to restore the flow into the vessel. All procedures were performed successfully. The technique of placing a guide wire into the left CCA via the right brachial artery before stent graft deployment is a safe and effective method that enables the precise visualization of the left CCA during the whole procedure. Moreover, in case of inadvertent complete or partial coverage of the origin of the left CCA, it supplies safe and quick access to the artery for stent implantation.« less

Advancement of wave generation and signal transmission in wire waveguides for structural health monitoring applications

NASA Astrophysics Data System (ADS)

Kropf, M.; Pedrick, M.; Wang, X.; Tittmann, B. R.

2005-05-01

As per the recent advances in remote in situ monitoring of industrial equipment using long wire waveguides (~10m), novel applications of existing wave generation techniques and new acoustic modeling software have been used to advance waveguide technology. The amount of attainable information from an acoustic signal in such a system is limited by transmission through the waveguide along with frequency content of the generated waves. Magnetostrictive, and Electromagnetic generation techniques were investigated in order to maximize acoustic transmission along the waveguide and broaden the range of usable frequencies. Commercial EMAT, Magnetostrictive and piezoelectric disc transducers (through the innovative use of an acoustic horn) were utilized to generate waves in the wire waveguide. Insertion loss, frequency bandwidth and frequency range were examined for each technique. Electromagnetic techniques are shown to allow for higher frequency wave generation. This increases accessibility of dispersion curves providing further versatility in the selection of guided wave modes, thus increasing the sensitivity to physical characteristics of the specimen. Both electromagnetic and magnetostrictive transducers require the use of a ferromagnetic waveguide, typically coupled to a steel wire when considering long transmission lines (>2m). The interface between these wires introduces an acoustic transmission loss. Coupling designs were examined with acoustic finite element software (Coupled-Acoustic Piezoelectric Analysis). Simulations along with experimental results aided in the design of a novel joint which minimizes transmission loss. These advances result in the increased capability of remote sensing using wire waveguides.

Transurethral Bougie-guided Placement of Suprapubic Catheter Over Guide Wire Monorail in Females: A Novel Technique.

PubMed

Dalela, Divakar; Gupta, Piyush; Dalela, Disha; Srinivas, A K; Bhaskar, Ved; Govil, Tuhina; Goel, Apul; Sankhwar, Satya Narayan

2016-08-01

To assess the safety and effectiveness of a novel transurethral bougie-guided monorail technique for suprapubic catheterization in females with vesicovaginal fistula. Patients undergoing transvaginal vesicovaginal fistula repair from February 2013 to December 2013 were selected. Suprapubic catheter was placed using this technique and assessment was done in terms of time taken, intraprocedural dislodgement or entanglement of catheter during the procedure, bleeding from the anterior abdominal wall or urethra, or any other intraoperative difficulty. All patients were catheterized smoothly without any intraoperative difficulty, with a mean time of 6 minutes. We describe a new technique of performing suprapubic cystostomy in patients, especially where the bladder cannot be distended. It is safe and easy to perform. Copyright © 2016 Elsevier Inc. All rights reserved.

A novel side branch protection technique in coronary stent implantation: Jailed Corsair technique.

PubMed

Numasawa, Yohei; Sakakura, Kenichi; Yamamoto, Kei; Yamamoto, Shingo; Taniguchi, Yousuke; Fujita, Hideo; Momomura, Shin-Ichi

2017-06-01

Side branch occlusion, which was one of the common complications in percutaneous coronary interventions, was closely associated with cardiac death and myocardial infarction. Clinical guidelines also support the importance of preservation of physiologic blood flow in SB during PCI to bifurcation lesions. In order to avoid side branch occlusion during stent implantation, we often performed the jailed wire technique, in which a conventional guide wire was inserted to the side branch before stent implantation to the main vessel. However, the jailed wire technique could not always prevent side branch occlusion. In this case report, we described a case of 72-year-old male suffering from angina pectoris. Coronary angiography revealed the diffuse calcified stenosis in the proximal and middle of left anterior descending coronary artery, and the large diagonal branch originated from the middle of the stenosis. To prevent side branch occlusion, we performed a novel side branch protection technique by using the Corsair microcatheter (Asahi Intecc, Nagoya, Japan). In this case report, we illustrated this "Jailed Corsair technique", and discussed the advantage compared to other side branch protection techniques such as the jailed balloon technique. Copyright © 2017 Elsevier Inc. All rights reserved.

Reoperation Rates in Ductal Carcinoma In Situ vs Invasive Breast Cancer After Wire-Guided Breast-Conserving Surgery.

PubMed

Langhans, Linnea; Jensen, Maj-Britt; Talman, Maj-Lis M; Vejborg, Ilse; Kroman, Niels; Tvedskov, Tove F

2017-04-01

New techniques for preoperative localization of nonpalpable breast lesions may decrease the reoperation rate in breast-conserving surgery (BCS) compared with rates after surgery with the standard wire-guided localization. However, a valid reoperation rate for this procedure needs to be established for comparison, as previous studies on this procedure include a variety of malignant and benign breast lesions. To determine the reoperation rate after wire-guided BCS in patients with histologically verified nonpalpable invasive breast cancer (IBC) or ductal carcinoma in situ (DCIS) and to examine whether the risk of reoperation is associated with DCIS or histologic type of the IBC. This nationwide study including women with histologically verified IBC or DCIS having wire-guided BCS performed between January 1, 2010, and December 31, 2013, used data from the Danish National Patient Registry that were cross-checked with the Danish Breast Cancer Group database and the Danish Pathology Register. Reoperation rate after wire-guided BCS in patients with IBC or DCIS. Wire-guided BCS was performed in 4118 women (mean [SD] age, 60.9 [8.7] years). A total of 725 patients (17.6%) underwent a reoperation: 593 were reexcisions (14.4%) and 132 were mastectomies (3.2%). Significantly more patients with DCIS (271 of 727 [37.3%]) than with IBC (454 of 3391 [13.4%]) underwent a reoperation (adjusted odds ratio, 3.82; 95% CI, 3.19-4.58; P < .001). After the first reexcision, positive margins were still present in 97 patients (16.4%). The risk of repeated positive margins was significantly higher in patients with DCIS vs those with IBC (unadjusted odds ratio, 2.21; 95% CI, 1.42-3.43; P < .001). The risk of reoperation was significantly increased in patients with lobular carcinoma vs those with ductal carcinoma (adjusted odds ratio, 1.44; 95% CI 1.06-1.95; P = .02). A total of 202 patients (4.9%) had a subsequent completion mastectomy, but no difference was found in the type of reoperation between patients with DCIS and those with IBC. A lower reoperation rate after wire-guided BCS was found in this study than those shown in previous studies. However, the risk of reoperation in patients with DCIS was 3 times higher than in those with IBC. The widespread use of mammographic screening will increase the number of patients diagnosed with DCIS, making a precise localization of nonpalpable DCIS lesions even more important.

Preliminary Experience with use of Qureshi-5 Catheters for Diagnostic Cerebral Angiography.

PubMed

Qureshi, Adnan I; Yan, Xiao; Liu, HongLiang

2015-05-01

A catheter technique was developed to overcome current challenges in the stabilization and manipulation of catheter in tortuous arteries such as right subclavian artery and left common carotid artery. The new catheter has the following two lumens: first lumen can accommodate a 0.035-inch guide wire (lumen A) and a curved shape at the distal end; the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen (lumen B). The catheter is withdrawn or advanced over the 0.018-inch guide wire and the curved free end of catheter manipulated until the end engages the origin of the target artery. Subsequently, either contrast can be injected or a 0.035-inch guide wire advanced into the target artery. The catheters were used in two patients to perform diagnostic cerebral angiography through a 6F introducer sheath placed in the right common femoral artery. The left and right common carotid arteries and left and right vertebral arteries were catheterized in first patient (contrast used 50 ml; fluoroscopy time 20:09 min). The left and right internal carotid arteries, left and right subclavian arteries, and left external carotid artery were catheterized in second patient (contrast used 40 ml; fluoroscopy time 13:56 min). No complications were observed in either of the two patients. The performance of the new catheter for catheterization of multiple arteries in two patients was considered adequate with high-quality angiographic image acquisitions.

Retrieval of a subintimal fractured guide wire from the brachial artery following saphenous vein graft stenting.

PubMed

Danson, Edward J; Ward, Michael

2015-06-01

We present a case of a 58-year-old woman with diabetes mellitus with a history of angina, coronary artery bypass 24 years previously and who underwent retrieval of a fractured coronary buddy wire from the right brachial artery following attempted coronary intervention to a saphenous vein graft via the right radial route. Attempted removal of the guide wire had caused guide catheter-induced dissection of the vein graft in addition to a distal stent edge dissection before fracture in the brachial artery. The fractured end of the buddy wire was found to be in the subintimal space and could only be retrieved by advancing the wire into the subclavian artery by means of wrapping its free portion around the guiding catheter. Its fractured end could then be snared into the guiding catheter but could only be withdrawn from behind the stented segment in the vein graft by means of a trap balloon in the guiding catheter. Successful stenting of a guide catheter-induced dissection and distal stent edge dissection within the vein graft was then performed. This case highlights the hazards of deploying stents over buddy wires and of fractured guide wires in coronary intervention. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Basic Wiring. Fourth Edition. Teacher Edition [and] Student Guide [and] Student Workbook 1 [and] Student Workbook 2.

ERIC Educational Resources Information Center

Kaltwasser, Stan; Flowers, Gary; Blasingame, Don

Basic Wiring, first in a series of three wiring publications, serves as the foundation for students enrolled in a wiring program. It is a prerequisite to Commercial and Industrial Wiring or Residential Wiring. Instructional materials include a teacher edition, student guide, and two student workbooks. The teacher edition begins with introductory…

Semi-rigid single hook localization the best method for localizing ground glass opacities during video-assisted thoracoscopic surgery: re-aerated swine lung experimental and primary clinical results

PubMed Central

Zhao, Guang; Sun, Long; Geng, Guojun; Liu, Hongming; Li, Ning; Liu, Suhuan; Hao, Bing

2017-01-01

Background The aim of this study was to compare the effects of currently available preoperative localization methods, including semi-rigid single hook-wire, double-thorn hook-wire, and microcoil, in localizing the pulmonary nodules, thus to select the best technology to assist video-assisted thoracoscopic surgery (VATS) for small ground glass opacities (GGO). Methods Preoperative CT-guided localizing techniques including semi-rigid single hook-wire, double-thorn hook-wire and microcoil were used in re-aerated fresh swine lung for location experiments. The advantages and drawbacks of the three positioning technologies were compared, and then the most optimal technique was used in patients with GGO. Technical success and post-operative complications were used as primary endpoints. Results All three localizing techniques were successfully performed in the re-aerated fresh swine lung. The median tractive force of semi-rigid single hook wire, double-thorn hook wire and microcoil were 6.5, 4.85 and 0.2 N, which measured by a spring dynamometer. The wound sizes in the superficial pleura, caused by unplugging the needles, were 2 mm in double-thorn hook wire, 1 mm in semi-rigid single hook and 1 mm in microcoil, respectively. In patients with GGOs, the semi-rigid hook wires localizations were successfully performed, without any complication that need to be intervened. Dislodgement was reported in one patient before VATS. No major complications related to the preoperative hook wire localization and VATS were observed. Conclusions We found from our localization experiments in the swine lung that, among the commonly used three localization methods, semi-rigid hook wire showed the best operability and practicability than double-thorn hook wire and microcoil. Preoperative localization of small pulmonary nodules with single semi-rigid hook wire system shows a high success rate, acceptable utility and especially low dislodgement in VATS. PMID:29312722

Management of Retained Intervention Guide-wire: A Literature Review

PubMed Central

Al-Moghairi, Abdulrahman M; Al-Amri, Hussein S

2013-01-01

Percutaneous coronary angioplasty is increasingly employed in the treatment of patients with complex coronary artery disease. Different steerable guide wires used to open occluded vessel and facilitate balloon and stent deployment. However, the guide-wire itself is not without hazard: it may perforate or dissect the vessel, but fracture or entrapment is uncommon. Its management depends on the clinical situation of the patient, as well as the position and length of the remnant. In this review we discuss the angioplasty guide-wire fracture and entrapment risk factors, potential risks and management. PMID:23116055

Electrode carrying wire for GTAW welding

NASA Technical Reports Server (NTRS)

Morgan, Gene E. (Inventor); Dyer, Gerald E. (Inventor)

1990-01-01

A welding torch for gas tungsten arc welding apparatus has a hollow tungsten electrode including a ceramic liner and forms the filler metal wire guide. The wire is fed through the tungsten electrode thereby reducing the size of the torch to eliminate clearance problems which exist with external wire guides. Since the wire is preheated from the tungsten more wire may be fed into the weld puddle, and the wire will not oxidize because it is always within the shielding gas.

Development of Active Catheter,Active Guide Wire and Micro Sensor Systems

PubMed Central

Haga, Y.; Mineta, T.; Totsu, K.; Makishi, W.; Esashi, M.

2001-01-01

Summary Active catheters and active guide wires which move like a snake have been developed for catheter-based minimally invasive diagnosis and therapy. Communication and control IC chips in the active catheter reduce the number of lead wires for control. The active catheter can be not only bent but also torsioned and extended. An ultra minature fiber-optic pressure sensor; a forward-looking ultrasonic probe and a magnetic position and orientation sensor have been developed for catheters and guide wires. These moving mechanisms and several sensors which are fitted near the tip of the catheter and the guide wire will provide detailed information near the tip and enable delicate and effective catheter intervention. PMID:20663389

Preliminary Experience with use of Qureshi-5 Catheters for Diagnostic Cerebral Angiography

PubMed Central

Qureshi, Adnan I.; Yan, Xiao; Liu, HongLiang

2015-01-01

BACKGROUND A catheter technique was developed to overcome current challenges in the stabilization and manipulation of catheter in tortuous arteries such as right subclavian artery and left common carotid artery. METHODS The new catheter has the following two lumens: first lumen can accommodate a 0.035-inch guide wire (lumen A) and a curved shape at the distal end; the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen (lumen B). The catheter is withdrawn or advanced over the 0.018-inch guide wire and the curved free end of catheter manipulated until the end engages the origin of the target artery. Subsequently, either contrast can be injected or a 0.035-inch guide wire advanced into the target artery. RESULTS The catheters were used in two patients to perform diagnostic cerebral angiography through a 6F introducer sheath placed in the right common femoral artery. The left and right common carotid arteries and left and right vertebral arteries were catheterized in first patient (contrast used 50 ml; fluoroscopy time 20:09 min). The left and right internal carotid arteries, left and right subclavian arteries, and left external carotid artery were catheterized in second patient (contrast used 40 ml; fluoroscopy time 13:56 min). No complications were observed in either of the two patients. CONCLUSIONS The performance of the new catheter for catheterization of multiple arteries in two patients was considered adequate with high-quality angiographic image acquisitions. PMID:26060529

Residential Wiring. Fourth Edition. Teacher Edition [and] Student Guide [and] Student Workbook.

ERIC Educational Resources Information Center

Taylor, Mark

Residential Wiring, the second publication in a series of three wiring publications, prepares students for entry-level employment in the residential wiring trade. Instructional materials include a teacher edition, student guide, and student workbook. The teacher edition begins with introductory pages, including a training and competency profile,…

Waveguide bends from nanometric silica wires

NASA Astrophysics Data System (ADS)

Tong, Limin; Lou, Jingyi; Mazur, Eric

2005-02-01

We propose to use bent silica wires with nanometric diameters to guide light as optical waveguide bend. We bend silica wires with scanning tunneling microscope probes under an optical microscope, and wire bends with bending radius smaller than 5 μm are obtained. Light from a He-Ne laser is launched into and guided through the wire bends, measured bending loss of a single bend is on the order of 1 dB. Brief introductions to the optical wave guiding and elastic bending properties of silica wires are also provided. Comparing with waveguide bends based on photonic bandgap structures, the waveguide bends from silica nanometric wires show advantages of simple structure, small overall size, easy fabrication and wide useful spectral range, which make them potentially useful in the miniaturization of photonic devices.

[Use of esophageal small balloon or papillary sphincter knife in the treatment of stent implantation 
for colorectal malignant obstruction].

PubMed

Xiao, Dinghua; Liu, Shaojun; Yan, Hanguang; Wang, Xiaoyan

2018-05-28

To explore the function of esophageal small balloon or papillary sphincter knife in the treatment of stent implantation for colorectal malignant obstruction, and to improve the success rate of colonic stent placement in such patients.
 Methods: A total of 49 patients with colorectal cancer complicated with almost complete obstruction or colorectal cancer were enrolled for this study. The esophageal small balloon or papillary sphincter knife was used in the guide wires. The guide wires gradually crossed the tumor gap and they were placed in the contralateral intestinal cavity with balloon progression. X-ray was then used to confirm whether the guide wire was inserted in the lesion intestinal cavity, and then the metal bare stent was inserted.
 Results: The guide wires was successfully inserted with conventional methods in these 49 cases, while they were also successfully placed the guide wire and the stent in the new way.
 Conclusion: For the patients with colorectal cancer complicated with complete obstruction or colorectal cancer located in obviously angled location, the use of esophageal small balloon or papillary sphincter knife can help the guide wire insert. They greatly improve the success rate of stent implantation.

Commercial and Industrial Wiring. Fourth Edition. Teacher Edition [and] Student Guide [and] Student Workbook 1 [and] Student Workbook 2.

ERIC Educational Resources Information Center

Kaltwasser, Stan; Flowers, Gary

Commercial and Industrial Wiring, third in a series of three wiring publications, includes the additional technical knowledge and applications required for job entry in the commercial and industrial wiring trade. Instructional materials include a teacher edition, student guide, and two student workbooks. The teacher edition begins with…

Radiofrequency Guide Wire Recanalization of Venous Occlusions in Patients with Malignant Superior Vena Cava Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Robert M.; David, Elizabeth; Pugash, Robyn A.

Fibrotic central venous occlusions in patients with thoracic malignancy and prior radiotherapy can be impassable with standard catheters and wires, including the trailing or stiff end of a hydrophilic wire. We report two patients with superior vena cava syndrome in whom we successfully utilized a radiofrequency guide wire (PowerWire, Baylis Medical, Montreal, Quebec, Canada) to perforate through the occlusion and recanalize the occluded segment to alleviate symptoms.

Tailor-made Surgical Guide Reduces Incidence of Outliers of Cup Placement.

PubMed

Hananouchi, Takehito; Saito, Masanobu; Koyama, Tsuyoshi; Sugano, Nobuhiko; Yoshikawa, Hideki

2010-04-01

Malalignment of the cup in total hip arthroplasty (THA) increases the risks of postoperative complications such as neck cup impingement, dislocation, and wear. We asked whether a tailor-made surgical guide based on CT images would reduce the incidence of outliers beyond 10 degrees from preoperatively planned alignment of the cup compared with those without the surgical guide. We prospectively followed 38 patients (38 hips, Group 1) having primary THA with the conventional technique and 31 patients (31 hips, Group 2) using the surgical guide. We designed the guide for Group 2 based on CT images and fixed it to the acetabular edge with a Kirschner wire to indicate the planned cup direction. Postoperative CT images showed the guide reduced the number of outliers compared with the conventional method (Group 1, 23.7%; Group 2, 0%). The surgical guide provided more reliable cup insertion compared with conventional techniques. Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Guide wire entrapment by inferior vena cava filters: an experimental study.

PubMed

Rosen, Michael J; Burns, Justin M; Cobb, William S; Jacobs, David G; Heniford, B Todd; Sing, Ronald F

2005-09-01

In situ vena cava filters are at risk for complications with the use of J-tipped guide wires. The purpose of this study was to evaluate the impact of two commonly used J-tipped guide wires on the stability of the four most recently released vena cava filters in an in vitro flow model. Four filters (OptEase [F1], Günther Tulip [F2], Vena Tech LP [F3], and Recovery [F4]) were inserted into an in vitro flow model. Two J-tipped guide wires (0.032-inch [GW-1], 0.035-inch [GW-2]) were passed through each filter (n = 50 passes per wire) for a distance of 10 cm. The inserter was blind as to the effects of the wire. The filters were monitored by an independent observer for adverse events occurring between the filters and the guide wires. These were defined as: migrations (>1 cm), change of position (tilt>10 degrees), and entrapment of the wire (unable to remove wire). Descriptive statistics, chi-square, and Fisher's exact test were used (p < 0.05 considered significant). GW-1 resulted in a lower incidence of entrapment, migration, and tilt for all filters compared with GW-2 (F1, p = 0.003; F2, p < 0.0001; F3, p < 0.0001; F4, p = 0.0004). GW-1 resulted in entrapment in 0%, migration in 7.5%, and tilt in 10.5% of insertions. GW-2 resulted in entrapment in 1%, migration in 26.5%, and tilt in 5.5% of insertions. The incidence of adverse events for GW-1 was significantly different compared with all filters (F1, 0%; F2, 46%; F3, 4%; and F4, 22%; p < 0.0001). Similarly, the incidence of adverse events for GW-2 was significantly different when evaluating all filters (F1, 12%; F2, 48%; F3, 22%; F4 60%; p < 0.0001). The smaller-diameter guide wire resulted in a decreased incidence of adverse events for all filters, but there is still risk for complications. Knowledge of potential complications associated with vena cava filters and the postinsertion use of guide wires are essential to avoid potential mishaps.

Percutaneous direct mitral annuloplasty using the Mitralign Bident system: description of the method and a case report.

PubMed

Siminiak, Tomasz; Dankowski, Rafał; Baszko, Artur; Lee, Christopher; Firek, Ludwik; Kałmucki, Piotr; Szyszka, Andrzej; Groothuis, Adam

2013-01-01

Functional mitral regurgitation (FMR) is known to contribute to a poor prognosis in patients with heart failure (HF). Current guidelines do not recommend cardiac surgery in patients with FMR and impaired ejection fraction due to the high procedural risk. Percutaneous techniques aimed at mitral valve repair may constitute an alternative to currently used routine medical treatment. To provide a description of a novel percutaneous suture-based technique of direct mitral annuloplasty using the Mitralign Bident system, as well as report our first case successfully treated with this method. A deflectable guiding catheter is advanced via the femoral route across the aortic valve to the posterior wall of the ventricle. A nested deflectable catheter is advanced through the guide toward the mitral annulus that allows the advancement of an insulated radiofrequency wire to cross the annulus. The wire is directed across the annulus in a target area that is 2-5 mm from the base of the leaflet into the annulus, as assessed by real-time 3D transoesophageal echocardiography. After placement of the first wire, another wire is positioned using a duel lumen bident delivery catheter, which provides a predetermined separation between wires (i.e. 14, 17 or 21 mm). Each wire provides a guide rail for implantation of sutured pledget implants within the annulus. Two pairs of pledgets are implanted, one pair in each of the P1 and P3 scallop regions of the posterior mitral annulus. A dedicated plication lock device is used to provide a means for plication of the annulus within each pair of the pledgets, and to retain the plication by delivering a suture locking implant. The plications result in improved leaflet coaptation and a reduction of the regurgitant orifice area. A 60-year-old female with diagnosed dilated cardiomyopathy, concomitant FMR class III and congestive HF was successfully treated with the Mitralign Bident system. Two pairs of pledgets were implanted resulting in an improvement of transoesophageal echocardiographic parameters, including proximal isovelocity surface area radius (0.7 cm to 0.4 cm), effective regurgitant orfice area (0.3 cm² to 0.1 cm²) and mitral regurgitant volume (49 mL to 10 mL). Percutaneous mitral annuloplasty with the Mitralign Bident system is feasible. Future clinical trials are needed to assess its safety and efficacy.

Evaluation of multilayer printed wiring boards by metallographic techniques: An illustrated guide to the preparation and inspection of plated-through hole test coupons based on the requirements of Mil-P-55110D

NASA Technical Reports Server (NTRS)

Jellison, J.

1986-01-01

This work is an illustrated handbook containing the rationale and procedure for the evaluation of multilayer printed wiring board construction integrity with respect to plated-through holes in accordance with the requirements of MIL-P-55110D, Printed Wiring Boards. It is intended as a practical aid for those concerned with determining the construction integrity of multilayer boards for high reliability applications. Photomicrographs of cross sectioned holes illustrate defect types, acceptable and unacceptable conditions, and methods of measurement. A procedure for specimen preparation is given, and appropriate paragraphs of the military specification are included and explained.

Simulation of minimally invasive vascular interventions for training purposes.

PubMed

Alderliesten, Tanja; Konings, Maurits K; Niessen, Wiro J

2004-01-01

To master the skills required to perform minimally invasive vascular interventions, proper training is essential. A computer simulation environment has been developed to provide such training. The simulation is based on an algorithm specifically developed to simulate the motion of a guide wire--the main instrument used during these interventions--in the human vasculature. In this paper, the design and model of the computer simulation environment is described and first results obtained with phantom and patient data are presented. To simulate minimally invasive vascular interventions, a discrete representation of a guide wire is used which allows modeling of guide wires with different physical properties. An algorithm for simulating the propagation of a guide wire within a vascular system, on the basis of the principle of minimization of energy, has been developed. Both longitudinal translation and rotation are incorporated as possibilities for manipulating the guide wire. The simulation is based on quasi-static mechanics. Two types of energy are introduced: internal energy related to the bending of the guide wire, and external energy resulting from the elastic deformation of the vessel wall. A series of experiments were performed on phantom and patient data. Simulation results are qualitatively compared with 3D rotational angiography data. The results indicate plausible behavior of the simulation.

Use of a very flexible guide wire to permit dilation of complex malignant strictures of the esophagus.

PubMed

Vargas-Tank, L; Ovalle, L; Fernández, C; Mella, B; Estay, R; del Solar, M P; Soto, J R

1995-01-01

Risk of perforation is a major impediment to the use of polyvinyl bougies in palliative dilation of cancerous strictures of the esophagus. We encountered 23 patients with complex malignant strictures in whom initial dilation with Savary-Gilliard bougies was thwarted because attempts to pass a conventional Eder-Puestow guide wire were unsuccessful. As a recourse, we probed these strictures with a very flexible guide wire of the type used to implant prostheses in the biliary tract. The purpose was to establish a passage through which a standard guide wire could then be inserted. The procedure was successful in all but 4 of the 23 patients. We conclude that in such cases the preliminary use of the very flexible guide, even though time-consuming, improves the chance of effective dilation with minimal added risk.

NASA Hybrid Reflectometer Project

NASA Technical Reports Server (NTRS)

Lynch, Dana; Mancini, Ron (Technical Monitor)

2002-01-01

Time-domain and frequency-domain reflectometry have been used for about forty years to locate opens and shorts in cables. Interpretation of reflectometry data is as much art as science. Is there information in the data that is being missed? Can the reflectometers be improved to allow us to detect and locate defects in cables that are not outright shorts or opens? The Hybrid Reflectometer Project was begun this year at NASA Ames Research Center, initially to model wire physics, simulating time-domain reflectometry (TDR) signals in those models and validating the models against actual TDR data taken on testbed cables. Theoretical models of reflectometry in wires will give us an understanding of the merits and limits of these techniques and will guide the application of a proposed hybrid reflectometer with the aim of enhancing reflectometer sensitivity to the point that wire defects can be detected. We will point out efforts by some other researchers to apply wire physics models to the problem of defect detection in wires and we will describe our own initial efforts to create wire physics models and report on testbed validation of the TDR simulations.

The BridgePoint devices to facilitate recanalization of chronic total coronary occlusions through controlled subintimal reentry.

PubMed

Werner, Gerald S

2011-01-01

In view of the improved long-term patency with drug-eluting stents, the challenge with chronic total coronary occlusion remains a low primary success rate. Modes of failure to open a chronic total coronary occlusion are mainly related to the inability to pass a wire through the proximal occlusion cap, and the most difficult part of the procedure is to guide the wire into the distal true lumen. A frequent situation is a subintimal wire position. The BridgePoint (BridgePoint Medical, MN, USA) family of devices is designed to cope with both of these problems. First, the CrossBoss™ catheter aims at passing through the proximal cap by manual rotation of a blunt proximal tip, and second, in case of a subintimal position, the Stingray™ balloon enables guided reentry from the subintimal space into the true lumen. Certain features of an occlusion might favor the CrossBoss device, while the reentry approach may also be used as a standalone bailout method. The aim is to provide a means to resolve otherwise failed attempts and to make it unnecessary to resort to the more complex and time-consuming retrograde wire techniques through collateral channels with the associated potential higher procedural risks.

Modern treatment of oesophageal strictures.

PubMed

Eastman, M C; Sali, A

1980-02-09

The results of 185 dilatations of oesophageal strictures with the rigid oesophagoscope are reported. The complication rate was 6%, which included five perforations (2.7%), and one death. The new technique of Eder-Puestow wire-guided dilatation was used in 20 cases without complication. These results, together with other reported experience of Eder-Puestow dilatation, suggest that this technique is superior to that of rigid dilatation on the grounds both of safety and of cost.

Plasma arc torch with coaxial wire feed

DOEpatents

Hooper, Frederick M

2002-01-01

A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

Pressure-assisted melt-filling and optical characterization of Au nano-wires in microstructured fibers.

PubMed

Lee, H W; Schmidt, M A; Russell, R F; Joly, N Y; Tyagi, H K; Uebel, P; Russell, P St J

2011-06-20

We report a novel splicing-based pressure-assisted melt-filling technique for creating metallic nanowires in hollow channels in microstructured silica fibers. Wires with diameters as small as 120 nm (typical aspect ration 50:1) could be realized at a filling pressure of 300 bar. As an example we investigate a conventional single-mode step-index fiber with a parallel gold nanowire (wire diameter 510 nm) running next to the core. Optical transmission spectra show dips at wavelengths where guided surface plasmon modes on the nanowire phase match to the glass core mode. By monitoring the side-scattered light at narrow breaks in the nanowire, the loss could be estimated. Values as low as 0.7 dB/mm were measured at resonance, corresponding to those of an ultra-long-range eigenmode of the glass-core/nanowire system. By thermal treatment the hollow channel could be collapsed controllably, permitting creation of a conical gold nanowire, the optical properties of which could be monitored by side-scattering. The reproducibility of the technique and the high optical quality of the wires suggest applications in fields such as nonlinear plasmonics, near-field scanning optical microscope tips, cylindrical polarizers, optical sensing and telecommunications.

Mountain Plains Learning Experience Guide: Electrical Wiring. Course: Electrical Wiring Trim-Out.

ERIC Educational Resources Information Center

Arneson, R.; And Others

One of two individualized courses included in an electrical wiring curriculum, this course covers electrical materials installation for the trim-out stage. The course is comprised of five units: (1) Outlets, (2) Fixtures, (3) Switches, (4) Appliances, and (5) Miscellaneous. Each unit begins with a Unit Learning Experience Guide that gives…

Ultrasonic thermometry using pulse techniques.

NASA Technical Reports Server (NTRS)

Lynnworth, L. C.; Carnevale, E. H.

1972-01-01

Ultrasonic pulse techniques have been developed which, when applied to inert gases, provide temperature measurements up to 8000 K. The response time can be less than 1 msec. This is a significant feature in studying shock-heated or combusting gases. Using a momentary contact coupling technique, temperature has been measured inside steel from 300 to 1500 K. Thin-wire sensors have been used above 2000 K in nuclear and industrial applications where conditions preclude the use of thermocouples, resistance devices, or optical pyrometers. At 2500 K, temperature sensitivity of 0.1% is obtained in Re wire sensors 5 cm long by timing five round trips with an electronic instrument that resolves the time interval between selected echoes to 0.1 microsec. Sensors have been operated at rotational speeds over 2000 rpm and in noisy environments. Temperature profiling of up to ten regions using only a single guided path or beam has also been accomplished.

Pre-operative localization of solitary pulmonary nodules with computed tomography-guided hook wire: report of 181 patients.

PubMed

Hanauer, Matthieu; Perentes, Jean Yannis; Krueger, Thorsten; Ris, Hans-Beat; Bize, Pierre; Schmidt, Sabine; Gonzalez, Michel

2016-01-16

Video-assisted thoracic surgery (VATS) is currently performed to diagnose and treat solitary pulmonary nodules (SPN). However, the intra-operative identification of deep nodules can be challenging with VATS as the lung is difficult to palpate. The aim of the study was to report the utility and the results of pre-operative computed tomography (CT)-guided hook wire localization of SPN. All records of the patients undergoing CT-guided hook wire localization prior to VATS resection for SPN between 2002 and 2013 were reviewed. The efficacy in localizing the nodule, hook wire complications, necessity to convert VATS to thoracotomy and the histology of SPN are reported. One hundred eighty-one patients (90 females, mean age 63 y, range 28-82 y) underwent 187 pulmonary resections after CT-guided hook wire localization. The mean SPN diameter was 10.3 mm (range: 4-29 mm). The mean distance of the lesion from the pleural surface was 11.6 mm (range: 0-45 mm). The mean time interval from hook wire insertion to VATS resection was 224 min (range 54-622 min). Hook wire complications included pneumothorax requiring chest tube drainage in 4 patients (2.1%) and mild parenchymal haemorrhage in 11 (5.9%) patients. Migration of the hook wire occurred in 7 patients (3.7%) although it did not affect the success of VATS resection (nodule location guided by the lung puncture site). Three patients underwent additional wedge resection by VATS during the same procedure because no lesion was identified in the surgical specimen. Conversion thoracotomy was required in 13 patients (7 %) for centrally localized lesions (6 patients) and pleural adhesions (7 patients). The mean operative time was 60 min (range 18-135 min). Pathological examination revealed a malignant lesion in 107 patients (59 %). The diagnostic yield was 98.3 %. VATS resection for SPN after CT-guided hook wire localization for SPN is safe and allows for proper diagnosis with a low thoracotomy conversion rate.

A simple customized surgical guide for orthodontic miniplates with tube.

PubMed

Paek, Janghyun; Su, Ming-Jeaun; Kwon, Soon-Yong; Kim, Seong-Hun; Chung, Kyu-Rhim; Nelson, Gerald

2012-09-01

This article reports the use of a customized surgical guide for simple and precise C-tube plate placement with minimized incision. Patients who were planning to have orthodontic miniplate treatment because of narrow interradicular space were recruited for this study. A combined silicone and stainless steel wire surgical guide for the C-tube was fabricated on the cast model. The taller wire of the positioning guide is used to accurately start the incision. The incision guide-wire position is verified by placing the miniplate on the coronal horizontal wire to confirm that the incision will coordinate with the screw holes. Because the miniplate is firmly held in place, there is no risk of the miniplate anchoring screws (diameter, 1.5 mm; length, 4 mm) sliding on the bone surface during placement with a manual hand driver. The surgical guide was placed on the clinical site, and it allowed precise placement of the miniplate with minimum incision and preventing from slippage or path-of-insertion angulation errors that might interfere with accurate placement. Customized surgical guide enables precise planning for miniplate positions in anatomically complex sites.

Development of a smart guide wire using an electrostrictive polymer: option for steerable orientation and force feedback

NASA Astrophysics Data System (ADS)

Ganet, F.; Le, M. Q.; Capsal, J. F.; Lermusiaux, P.; Petit, L.; Millon, A.; Cottinet, P. J.

2015-12-01

The development of steerable guide wire or catheter designs has been strongly limited by the lack of enabling actuator technologies. This paper presents the properties of an electrostrive actuator technology for steerable actuation. By carefully tailoring material properties and the actuator design, which can be integrated in devices, this technology should realistically make it possible to obtain a steerable guide wire design with considerable latitude. Electromechanical characteristics are described, and their impact on a steerable design is discussed.

Stents in Renal Artery Bifurcation Stenosis: A Case Report

PubMed Central

Leonardou, Polytimi; Pappas, Paris

2011-01-01

A 39-year-old patient presented with poorly controlled hypertension, and she was referred to renal angiogram and potential renal angioplasty. Renal angiogram showed a bifurcation lesion of the right renal artery. A guide wire was used to cross the upper branch, while the lower branch was protected by another same-type guide wire through the same introducer. Two thin monorail balloons were used to dilate the two branches; however, despite balloon dilatation, the stenosis of the vessels persisted. The “kissing balloon” technique was then attempted by simultaneously inflating both branches using the same balloons, but more than a 70% residual stenosis persisted in each branch. Two stents were finally placed in a “kissing” way through the main renal artery. The imaging and clinical results were good, without any procedure-related complications. Three years clinical followup was also good, without any reason for further interventional approach. PMID:21789043

Wire-Guide Manipulator For Automated Welding

NASA Technical Reports Server (NTRS)

Morris, Tim; White, Kevin; Gordon, Steve; Emerich, Dave; Richardson, Dave; Faulkner, Mike; Stafford, Dave; Mccutcheon, Kim; Neal, Ken; Milly, Pete

1994-01-01

Compact motor drive positions guide for welding filler wire. Drive part of automated wire feeder in partly or fully automated welding system. Drive unit contains three parallel subunits. Rotations of lead screws in three subunits coordinated to obtain desired motions in three degrees of freedom. Suitable for both variable-polarity plasma arc welding and gas/tungsten arc welding.

Percutaneous Sacroiliac Screw Placement: A Prospective Randomized Comparison of Robot-assisted Navigation Procedures with a Conventional Technique

PubMed Central

Wang, Jun-Qiang; Wang, Yu; Feng, Yun; Han, Wei; Su, Yong-Gang; Liu, Wen-Yong; Zhang, Wei-Jun; Wu, Xin-Bao; Wang, Man-Yi; Fan, Yu-Bo

2017-01-01

Background: Sacroiliac (SI) screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot™ is an orthopedic surgery robot which can be used for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique. Methods: Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher's exact probability test was used to analyze the screws’ positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed. Results: Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value (0.009) showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group (median [Q1, Q3]: 6.0 [6.0, 9.0] s vs. median [Q1, Q3]: 36.0 [21.5, 48.0] s; χ2 = 13.590, respectively, P < 0.001); no difference in operation time after reduction of the pelvis was noted (χ2 = 1.990, P = 0.158). Time for guide wire insertion was significantly shorter for the robot-assisted group than that for the freehand group (median [Q1, Q3]: 2.0 [2.0, 2.7] min vs. median [Q1, Q3]: 19.0 [15.5, 45.0] min; χ2 = 20.952, respectively, P < 0.001). The number of guide wire attempts in the robot-assisted group was significantly less than that in the freehand group (median [Q1, Q3]: 1.0 [1.0,1.0] time vs. median [Q1, Q3]: 7.0 [1.0, 9.0] times; χ2 = 15.771, respectively, P < 0.001). The instrumented SI levels did not differ between both groups (from S1 to S2, χ2 = 4.760, P = 0.093). Conclusions: Accuracy of the robot-assisted technique was superior to that of the freehand technique. Robot-assisted navigation is safe for unstable posterior pelvic ring stabilization, especially in S1, but also in S2. SI screw insertion with robot-assisted navigation is clinically feasible. PMID:29067950

Percutaneous Sacroiliac Screw Placement: A Prospective Randomized Comparison of Robot-assisted Navigation Procedures with a Conventional Technique.

PubMed

Wang, Jun-Qiang; Wang, Yu; Feng, Yun; Han, Wei; Su, Yong-Gang; Liu, Wen-Yong; Zhang, Wei-Jun; Wu, Xin-Bao; Wang, Man-Yi; Fan, Yu-Bo

2017-11-05

Sacroiliac (SI) screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot™ is an orthopedic surgery robot which can be used for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique. Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher's exact probability test was used to analyze the screws' positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed. Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value (0.009) showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group (median [Q1, Q3]: 6.0 [6.0, 9.0] s vs. median [Q1, Q3]: 36.0 [21.5, 48.0] s; χ2 = 13.590, respectively, P < 0.001); no difference in operation time after reduction of the pelvis was noted (χ2 = 1.990, P = 0.158). Time for guide wire insertion was significantly shorter for the robot-assisted group than that for the freehand group (median [Q1, Q3]: 2.0 [2.0, 2.7] min vs. median [Q1, Q3]: 19.0 [15.5, 45.0] min; χ2 = 20.952, respectively, P < 0.001). The number of guide wire attempts in the robot-assisted group was significantly less than that in the freehand group (median [Q1, Q3]: 1.0 [1.0,1.0] time vs. median [Q1, Q3]: 7.0 [1.0, 9.0] times; χ2 = 15.771, respectively, P < 0.001). The instrumented SI levels did not differ between both groups (from S1 to S2, χ2 = 4.760, P = 0.093). Accuracy of the robot-assisted technique was superior to that of the freehand technique. Robot-assisted navigation is safe for unstable posterior pelvic ring stabilization, especially in S1, but also in S2. SI screw insertion with robot-assisted navigation is clinically feasible.

Electricity: Residential Wiring. Secondary Schools. Curriculum Guide.

ERIC Educational Resources Information Center

Trust Territory of the Pacific Islands Dept. of Education, Saipan.

This curriculum guide on residential wiring for secondary students is one of six developed for inservice teachers at Marianas High School in Saipan. The guide provides the rationale, description, goals, and objectives of the program; the program of studies and performance objectives by levels; samples of lesson plans for effective delivery of…

Ureteric catheterization via an ileal conduit: technique and retrieval of a JJ stent.

PubMed

Wah, T M; Kellett, M J

2004-11-01

Retrograde ureteric catheterization of a patient with an ileal conduit is difficult, because guide wires and catheters coil in the conduit. A modified loopogram, using a Foley catheter as a fulcrum through which catheters can be advanced to the ureteric anastomosis, is described. This technique was used to remove a JJ stent, which had been inserted previously across a stricture in one ureter, the stent crossing from one kidney to the other.

Subarachnoid and basal cistern navigation through the sacral hiatus with guide wire assistance.

PubMed

Layer, Lauren; Riascos, Roy; Firouzbakht, Farhood; Amole, Adewumi; Von Ritschl, Rudiger; Dipatre, Pier; Cuellar, Hugo

2011-07-01

Intraspinal navigation with catheters and fiberscopes has shown feasible results for diagnosis and treatment of intraspinal and intracranial lesions. The most common approach, lumbar puncture, has allowed access to the spinal cord, however, coming with the difficulties of fiberscope damage and decreased torque for guidance. Our objective in this study is to allow an alternate access, the sacral hiatus, with guide wire assistance into the subarachnoid and intracranial structures, while easing the angle of entry and increasing torque. We advanced catheters with guide wire and fluoroscopy assistance into the sacral hiatus of three cadavers. After entry, the thecal sac was punctured and the catheter with guide wire was advanced rostrally until positioned in the basal cisterns of the brain. We confirmed catheter placement with contrast injection, autopsy, and dissection. In our study, the sacral hiatus was easily accessed, but resistance was found when attempting to puncture the thecal sac. The advancement of the catheter with guide wire assistance glided easily rostrally until some mild resistance was discovered at entry into the foramen magnum. With redirection, all catheters passed with ease into the basal cisterns. Positioning was confirmed with contrast injection with fluoroscopy evidence, autopsy, and dissection. There was no macroscopic or microscopic evidence of damage to the spinal roots, spinal cord, or cranial nerves. The sacral hiatus with guide wire assistance is an accessible conduit for uncomplicated entry into the subarachnoid and basal cistern space without damaging surrounding structures.

Positioning and joining of organic single-crystalline wires

PubMed Central

Wu, Yuchen; Feng, Jiangang; Jiang, Xiangyu; Zhang, Zhen; Wang, Xuedong; Su, Bin; Jiang, Lei

2015-01-01

Organic single-crystal, one-dimensional materials can effectively carry charges and/or excitons due to their highly ordered molecule packing, minimized defects and eliminated grain boundaries. Controlling the alignment/position of organic single-crystal one-dimensional architectures would allow on-demand photon/electron transport, which is a prerequisite in waveguides and other optoelectronic applications. Here we report a guided physical vapour transport technique to control the growth, alignment and positioning of organic single-crystal wires with the guidance of pillar-structured substrates. Submicrometre-wide, hundreds of micrometres long, highly aligned, organic single-crystal wire arrays are generated. Furthermore, these organic single-crystal wires can be joined within controlled angles by varying the pillar geometries. Owing to the controllable growth of organic single-crystal one-dimensional architectures, we can present proof-of-principle demonstrations utilizing joined wires to allow optical waveguide through small radii of curvature (internal angles of ~90–120°). Our methodology may open a route to control the growth of organic single-crystal one-dimensional materials with potential applications in optoelectronics. PMID:25814032

Coronary angioscopy: a monorail angioscope with movable guide wire.

PubMed

Nanto, S; Ohara, T; Mishima, M; Hirayama, A; Komamura, K; Matsumura, Y; Kodama, K

1991-03-01

A new angioscope was devised for easier visualization of the coronary artery. In its tip, the angioscope (Olympus) with an outer diameter of 0.8 mm had a metal lumen, through which a 0.014-in steerable guide wire passed. Using a 8F guiding catheter and a guide wire, it was introduced into the distal coronary artery. With injection of warmed saline through the guiding catheter, the coronary segments were visualized. In the attempted 70 vessels (32 left anterior descending [LAD], 10 right coronary [RCA], 28 left circumflex [LCX]) from 48 patients, 60 vessels (86%) were successfully examined. Twenty-two patients who underwent attempted examination of both LAD and LCX; both coronary arteries were visualized in 19 patients (86%). In the proximal site of the lesion, 40 patients have the diagonal branch or the obtuse marginal branch. In 34 patients (85%) the angioscope was inserted beyond these branches. In 12 very tortuous vessels, eight vessels (67%) were examined. In conclusion, the new monorail coronary angioscope with movable guide wire is useful to examine the stenotic lesions of the coronary artery.

Evaluation of a novel, ultrathin, tip-bending endoscope in a synthetic force-sensing pancreas with comparison to medical guide wires

PubMed Central

Chandler, John E; Lee, Cameron M; Babchanik, Alexander P; Melville, C David; Saunders, Michael D; Seibel, Eric J

2012-01-01

Purpose Direct visualization of pancreatic ductal tissue is critical for early diagnosis of pancreatic diseases and for guiding therapeutic interventions. A novel, ultrathin (5 Fr) scanning fiber endoscope (SFE) with tip-bending capability has been developed specifically to achieve high resolution imaging as a pancreatoscope during endoscopic retrograde cholangiopancreatography (ERCP). This device has potential to dramatically improve both diagnostic and therapeutic capabilities during ERCP by providing direct video feedback and tool guidance to clinicians. Methods Invasiveness of the new tip-bending SFE was evaluated by a performance comparison to ERCP guide wires, which are routinely inserted into the pancreatic duct during ERCP. An in vitro test model with four force sensors embedded in a synthetic pancreas was designed to detect and compare the insertion forces for 0.89 mm and 0.53 mm diameter guide wires as well as the 1.7 mm diameter SFE. Insertions were performed through the working channel of a therapeutic duodenoscope for the two types of guide wires and using a statistically similar direct insertion method for comparison to the SFE. Results Analysis of the forces detected by the sensors showed the smaller diameter 0.53 mm wire produced significantly less average and maximum forces during insertion than the larger diameter 0.89 mm wire. With the use of tip-bending and optical visualization, the 1.7 mm diameter SFE produced significantly less average force during insertion than the 0.89 mm wire at every sensor, despite its larger size. It was further shown that the use of tip-bending with the SFE significantly reduced the forces at all sensors, compared to insertions when tip-bending was not used. Conclusion Combining high quality video imaging with two-axis tip-bending allows a larger diameter guide wire-style device to be inserted into the pancreatic duct during ERCP with improved capacity to perform diagnostics and therapy. PMID:23166452

Graph-based geometric-iconic guide-wire tracking.

PubMed

Honnorat, Nicolas; Vaillant, Régis; Paragios, Nikos

2011-01-01

In this paper we introduce a novel hybrid graph-based approach for Guide-wire tracking. The image support is captured by steerable filters and improved through tensor voting. Then, a graphical model is considered that represents guide-wire extraction/tracking through a B-spline control-point model. Points with strong geometric interest (landmarks) are automatically determined and anchored to such a representation. Tracking is then performed through discrete MRFs that optimize the spatio-temporal positions of the control points while establishing landmark temporal correspondences. Promising results demonstrate the potentials of our method.

Spring control of wire harness loops

NASA Technical Reports Server (NTRS)

Curcio, P. J.

1979-01-01

Negator spring control guides wire harness between movable and fixed structure. It prevents electrical wire harness loop from jamming or being severed as wire moves in response to changes in position of aircraft rudder. Spring-loaded coiled cable controls wire loop regardless of rudder movement.

Self-inflicted long complex urethro-vesical foreign body: is open surgery always needed?

PubMed Central

Garg, Manish; Kumar, Manoj; Sankhwar, Satyanarayan; Singh, Vishwajeet

2013-01-01

In this case report, we describe our experience of a self-inflicted long complex urethrovesical foreign body managed suprapubically through the minimally invasive technique. A 21-year-old man with antipsychotic treatment for the past 10 years presented with a long electric cable wire in his bladder with the distal end in the penile urethra. He presented with symptoms of voiding difficulty and gross haematuria. An attempt of gentle retrieval of wire through the cystoscopic forceps was not successful due to a very complex knot of cable in the bladder. To avoid open surgery such as suprapubic cystotomy, the percutaneous minimally invasive approach was planned. Access to the bladder was achieved by the suprapubic puncture of the bladder, placement of a guide-wire and serial dilation of supra-pubic tract. With the help of nephroscope, through suprapubic tract, the cable wire was retrieved antegradely without causing undue trauma to the bladder or urethra. PMID:23749820

Amplatzer Vascular Plug Anchoring Technique to Stabilize the Delivery System for Microcoil Embolization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onozawa, Shiro, E-mail: onozawa@nms.ac.jp; Murata, Satoru, E-mail: genji@nms.ac.jp; Mine, Takahiko, E-mail: takahikomine@gmail.com

PurposeTo evaluate the feasibility of a novel embolization technique, the Amplatzer vascular plug (AVP) anchoring technique, to stabilize the delivery system for microcoil embolization.Materials and methodsThree patients were enrolled in this study, including two cases of internal iliac artery aneurysms and one case of internal iliac arterial occlusion prior to endovascular aortic repair. An AVP was used in each case for embolization of one target artery, and the AVP was left in place. The AVP detachment wire was then used as an anchor to stabilize the delivery system for microcoil embolization to embolize the second target artery adjacent to themore » first target artery. The microcatheter for the microcoils was inserted parallel to the AVP detachment wire in the guiding sheath or catheter used for the AVP.ResultsThe AVP anchoring technique was achieved and the microcatheter was easily advanced to the second target artery in all three cases.ConclusionThe AVP anchoring technique was found to be feasible to advance the microcatheter into the neighboring artery of an AVP-embolized artery.« less

Iatrogenic submucosal tunnel in the ureter: a rare complication during advancement of the guide wire.

PubMed

El Darawany, Hamed; Barakat, Alaa; Madi, Maha Al; Aldamanhori, Reem; Al Otaibi, Khalid; Al-Zahrani, Ali A

2016-01-01

Inserting a guide wire is a common practice during endo-urological procedures. A rare complication in patients with ureteral stones where an iatrogenic submucosal tunnel (IST) is created during endoscopic guide wire placement. Summarize data on IST. Retrospective descriptive study of patients treated from from October 2009 until January 2015. King Fahd Hospital of the University, Al-Khobar, Saudi Arabia. Patients with ureteral stones were divided to 2 groups. In group I (335 patients), the ureteral stones were removed by ureteroscopy in one stage. Group II (97 patients) had a 2-staged procedure starting with a double J-stent placement for kidney drainage followed within 3 weeks with ureteroscopic stone removal. Endoscopic visualization of ureteric submucosal tunneling by guide wire. IST occurred in 9/432 patients with ureteral stones (2.1%). The diagnosis in group I was made during ureteroscopy by direct visualization of a vanishing guide wire at the level of the stone (6 patients). In group II, IST was suspected when renal pain was not relieved after placement of the double J-stent or if imaging by ultrasound or intravenous urography showed persistent back pressure to the obstructed kidney (3 patients). The condition was subsequently confirmed by ureteroscopy. Forceful advancement of the guide wire in an inflamed and edematous ureteral segment impacted by a stone is probably the triggering factor for development of IST. Definitive diagnosis is possible only by direct visualization during ureteroscopy. Awareness of this potential complication is important to guard against its occurrence. Relatively small numbers of subjects and the retrospective nature of the study.

Magnetic guide-wire navigation in pulmonary and systemic arterial catheterization: initial experience in pigs.

PubMed

Grosse-Wortmann, Lars; Grabitz, Ralf; Seghaye, Marie-Christine

2007-04-01

Cardiovascular catheterization can be challenging whenever a stenosis or an abnormal vascular course interferes with probing the target vessel. This study addresses the feasibility of navigating a guide wire with a magnetic tip by an external magnetic field through pulmonary and systemic arteries in an experimental porcine model. We investigated six piglets using magnetic guide-wire navigation. Two pulmonary arteriograms were taken from different angles in order to reconstruct the three-dimensional vessel anatomy. A computer interface then calculated three-dimensional coordinates for the vessel in space. Using these coordinates, two external magnets were positioned to create magnetic vectors along the expected vessel course. Magnetically enabled guide wires were then navigated into the vessels using the magnetic field to orient the guide-wire tips. Aortic and renal branches were addressed in a similar fashion. Difficulty in reaching the target vessel was reflected by the number of attempts that were necessary. After 10 failed attempts, the maneuver was recorded to have failed. Thirty-five of 37 (94.6%) arteries with branches at acute angles were reached successfully using magnetic navigation. In two pigs, the left upper lobe artery could not be probed. Peripheral arteries of small diameter were easier to reach than large central arteries, requiring less attempts. Magnetic guide-wire navigation is feasible in the arteries of the lungs, the head and neck, and the kidneys. It is particularly useful in entering small arterial branches at acute angles and may facilitate interventional therapy in a variety of vascular diseases in children and adults.

SU-E-T-255: Optimized Supine Craniospinal Irradiation with Image-Guided and Field Matched Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Z; Holupka, E; Naughton, J

2014-06-01

Purpose: Conventional craniospinal irradiation (CSI) challenges include dose inhomogeneity at field junctions and position uncertainty due to the field divergence, particular for the two spinal fields. Here we outline a new supine CSI technique to address these difficulties. Methods: Patient was simulated in supine position. The cranial fields had isocenter at C2/C3 vertebral and were matched with 1st spinal field. Their inferior border was chosen to avoid the shoulder, as well as chin from the 1st spine field. Their collimator angles were dependent on asymmetry jaw setting of the 1st spinal field. With couch rotation, the spinal field gantry anglesmore » were adjusted to ensure, the inferior border of 1st and superior border of 2nd spinal fields were perpendicular to the table top. The radio-opaque wire position for the spinal junction was located initially by the light field from an anterior setup beam, and was finalized by the portal imaging of the 1st spinal field. With reference to the spinal junction wire, the fields were matched by positioning the isocenter of the 2nd spinal field. A formula was derived to optimize supine CSI treatment planning, by utilizing the relationship among the Yjaw setting, the spinal field gantry angles, cranial field collimator angles, and the spinal field isocenters location. The plan was delivered with portal imaging alignment for the both cranial and spinal junctions. Results: Utilizing this technique with matching beams, and conventional technique such as feathering and forwarding planning, a homogenous dose distribution was achieved throughout the entire CSI treatment volume including the spinal junction. Placing the spinal junction wire visualized in both spinal portals, allows for precise determination and verification of the appropriate match line of the spine fields. Conclusion: This technique of optimization supine CSI achieved a homogenous dose distributions and patient localization accuracy with image-guided and matched beams.« less

Therapeutic peroral direct cholangioscopy using a single balloon enteroscope in patients with Roux-en-Y anastomosis (with videos).

PubMed

Yamauchi, Hiroshi; Kida, Mitsuhiro; Okuwaki, Kosuke; Miyazawa, Shiro; Matsumoto, Takaaki; Uehara, Kazuho; Miyata, Eiji; Hasegawa, Rikiya; Kaneko, Toru; Laopeamthong, Issaree; Lei, Yang; Iwai, Tomohisa; Imaizumi, Hiroshi; Koizumi, Wasaburo

2018-01-01

Peroral cholangioscopic lithotripsy is a useful procedure in patients with a normal gastrointestinal anatomy who have difficult-to-treat stones. We evaluated the usefulness of peroral direct cholangioscopy (PDCS) using single-balloon enteroscope (SBE) in patients with difficult-to-treat stones who had undergone Roux-en-Y reconstruction. Among 118 patients (169 sessions) who underwent SBE-assisted endoscopic retrograde cholangiopancreatography to treat biliary stones after Roux-en-Y reconstruction, patients in whom it was difficult to remove biliary stones via a transpapillary or transanastomotic approach and difficult to switch to ultra-slim endoscope, were retrospectively enrolled. The biliary insertion success rate, procedure success rate, procedure time, and procedural complications were assessed. The SBE was inserted into the bile-duct, first using a free-hand technique, second using a guide wire, and third using the large balloon anchoring and deflation (LBAD) technique. A total of 11 patients (14 sessions) were enrolled in this study. The biliary insertion success rate was 100%. Bile-duct insertion was performed using a free-hand technique in 4 sessions, a guide wire in 3 sessions (rendezvous technique, 2 sessions), and the LBAD technique in 7 sessions. The procedure success rate was 86% in first session, and 100% in second session. The median procedure time was 81 min (range 49-137). The median procedure time in the bile-duct was 21.5 min (range 6-60). Mild pancreatitis occurred as a complication in one patient. The median follow-up was 528 days (range 282-764). No patient had stone recurrence. PDCS using SBE is a useful procedure in patients with Roux-en-Y reconstruction. The LBAD technique is an useful technique of inserting SBE into the bile-duct.

Use of fluoroscopy-guided wire manipulation and/or laparoscopic surgery in the repair of malfunctioning peritoneal dialysis catheters.

PubMed

Kim, Hee Jin; Lee, Tae Won; Ihm, Chun Gyoo; Kim, Myung Jae

2002-01-01

Peritoneal catheter is the lifeline for the continuous ambulatory peritoneal dialysis (CAPD) patients. Over the years, obstruction or displacement of the CAPD catheter has been one of the common complications of CAPD. Fluoroscopy-guided wire manipulation or laparoscopic surgery has been developed to manage outflow obstruction. We analyzed the catheter outcome of fluoroscopy-guided wire manipulation or laparoscopic surgery to determine the ultimate benefit of these procedures. From June 1996 to August 2000, catheter complications were manipulated in 24 patients. Eleven (46%) of these patients were initially managed by guide wire under fluoroscopic control. The remaining 13 (54%) patients were manipulated by laparoscopic surgery. A successful outcome was defined as maintained normal peritoneal catheter function at 30 days after the manipulations. Among the catheters manipulated, 18 (75%) were inserted by nephrologist and 6 (25%) by surgeons at the initiation of CAPD. Tenckhoff double-cuff peritoneal catheters were inserted to all patients. The time elapsed between catheter insertion and manipulation varied from 1 to 60 days with a mean of 11 days. The primary causes of catheter malfunction were kinking in 1 case, omental wrapping with adhesions in 9 cases, and catheter displacements in the remaining 14 cases. Thirty-day catheter function was achieved in 50% (12/24) of initial catheter manipulations, with guide wire under fluoroscopic control (46%, 5/11) and laparoscopic surgery (54%, 7/13). Overall success rate of repeated manipulation was 71% (17 of 24). The successful outcome in repairing of the malfunctioning CAPD catheters could be increased by the combination of fluoroscopy-guided wire manipulation and laparoscopic surgery. Copyright 2002 S. Karger AG, Basel

REcanalisation and Balloon-Oriented Puncture for Re-Insertion of Dialysis Catheter in Nonpatent Central Veins (REBORN)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Too, Chow Wei, E-mail: toochowwei@gmail.com; Sayani, Raza; Lim, Elvin Yuan Ting

PurposeTo describe a technique involving REcanalisation and Balloon-Oriented puncture for Re-insertion of dialysis catheter in Nonpatent central veins (REBORN) and to report long-term results.Materials and MethodsThis is a retrospective study of ten subjects in whom dialysis catheters were inserted using the REBORN technique from March 2012 to October 2014 and followed up till April 2016. Data on the duration of catheter usage, complications and reasons for removal were obtained. Seven patients had partially occluded lower internal jugular veins (IJV) recanalised in an antegrade fashion via a more cranial puncture. The balloon was then inflated at usual puncture site with anmore » 18G needle. The collapsed balloon was cannulated with a guide wire, and both balloon and guide wire were advanced together into the superior vena cava. This was followed by tunnelled catheter placement using standard techniques. Two patients had catheters placed in the subclavian vein using a similar antegrade technique, and one patient had catheter placed via the left IJV following retrograde recanalisation from a right femoral puncture.ResultsMean duration of catheter use was 278 days (range 32–503). Three catheters were removed due to matured arteriovenous accesses. Four patients had successful catheter change over the same subcutaneous track due to catheter malfunction. One catheter was removed after 7 months because of sepsis. No complications were reported.ConclusionThe REBORN technique allows for the preservation of central veins for future haemodialysis access, which can be challenging in patients requiring long-term dialysis.« less

Prospective comparison of two management strategies of central venous catheters in burn patients.

PubMed

Kealey, G P; Chang, P; Heinle, J; Rosenquist, M D; Lewis, R W

1995-03-01

Central venous catheters (CVCs) are associated with sepsis in burn patients. This study was undertaken to compare two strategies of CVC management in patients with major burn injuries. Forty-two burn patients with major burn injuries were randomly assigned to undergo site change every 48 hours of the CVC or to undergo wire guide exchange of the CVC every 48 hours at the same site. Catheter insertion site, distance from the burn wound, cultures of catheter tips, and blood cultures were obtained from all patients in a prospective manner. There was no difference in the incidence of CVC sepsis between the two groups studied. CVCs inserted less than 5 cm from the burn wound developed bacterial contamination at an earlier time than CVCs inserted more than 5 cm from the burn wound. There was no advantage to changing the CVC insertion site every 48 hours. Changing the CVC using the wire guide technique did not prevent, nor predict, CVC bacterial contamination.

Radioguided localisation of impalpable breast lesions using 99m-Technetium macroaggregated albumin: Lessons learnt during introduction of a new technique to guide preoperative localisation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landman, Joanne; Kulawansa, Sagarika; McCarthy, Michael

2015-03-15

Preoperative wire-guided localisation (WGL) of impalpable breast lesions is widely used but can be technically difficult. Risks include wire migration, inaccurate placement, and inadequate surgical margins. Research shows that radioguided occult lesion localisation (ROLL) is quicker, easier, and can improve surgical and cosmetic outcomes. An audited introduction of ROLL was conducted to validate the technique as a feasible alternative to WGL. Fifty patients with single impalpable lesions and biopsy proven malignancy or indeterminate histology underwent WGL followed by intralesional radiopharmaceutical injection of 99m-Technetium macroaggregated albumin. Postprocedural mammography was performed to demonstrate wire position, and scintigraphy to evaluate radiopharmaceutical migration. Lymphoscintigraphymore » and intraoperative sentinel node biopsy were performed if indicated, followed by lesion localisation and excision using a gamma probe. Specimen imaging was performed, with immediate reexcision for visibly inadequate margins. Accurate localisation was achieved in 86% of patients with ROLL compared to 72% with WGL. All lesions were successfully removed, with clear margins in 71.8% of malignant lesions. Reexcision and intraoperative sentinel node localisation rates were equivalent to preaudit figures for WGL. ROLL was easy to perform and problems were infrequent. Inaccurate radiopharmaceutical placement necessitating WGL occurred in four patients. Minor radiopharmaceutical migration was common, but precluded using ROLL in only two cases. ROLL is effective, simple, inexpensive, and easily learnt; however, preoperative confirmation of correct radiopharmaceutical placement using mammography and the gamma probe is important to help ensure successful lesion removal. Insertion of a backup hookwire is recommended during the initial introduction of ROLL.« less

Vocational Preparation Curriculum: Electrical Wiring.

ERIC Educational Resources Information Center

Usoro, Hogan

This document is a curriculum guide for instructors teaching vocational preparation for electrical wiring to special needs students. The purpose of the curriculum guide is to provide minimum skills for disadvantaged and handicapped students entering the mainstream; to supplement vocational skills of those students already in a regular training…

Residential Wiring. Second Edition.

ERIC Educational Resources Information Center

Taylor, Mark; And Others

This guide is designed to assist teachers conducting a course to prepare students for entry-level employment in the residential wiring trade. Included in the guide are six instructional units and the following sections of information for teachers: guidelines in using the unit components; academic and workplace skills classifications and…

Early experience of placing image-guided minimally invasive pedicle screws without K-wires or bone-anchored trackers.

PubMed

Malham, Gregory M; Parker, Rhiannon M

2018-04-01

OBJECTIVE Image guidance for spine surgery has been reported to improve the accuracy of pedicle screw placement and reduce revision rates and radiation exposure. Current navigation and robot-assisted techniques for percutaneous screws rely on bone-anchored trackers and Kirchner wires (K-wires). There is a paucity of published data regarding the placement of image-guided percutaneous screws without K-wires. A new skin-adhesive stereotactic patient tracker (SpineMask) eliminates both an invasive bone-anchored tracker and K-wires for pedicle screw placement. This study reports the authors' early experience with the use of SpineMask for "K-wireless" placement of minimally invasive pedicle screws and makes recommendations for its potential applications in lumbar fusion. METHODS Forty-five consecutive patients (involving 204 screws inserted) underwent K-wireless lumbar pedicle screw fixation with SpineMask and intraoperative neuromonitoring. Screws were inserted by percutaneous stab or Wiltse incisions. If required, decompression with or without interbody fusion was performed using mini-open midline incisions. Multimodality intraoperative neuromonitoring assessing motor and sensory responses with triggered electromyography (tEMG) was performed. Computed tomography scans were obtained 2 days postoperatively to assess screw placement and any cortical breaches. A breach was defined as any violation of a pedicle screw involving the cortical bone of the pedicle. RESULTS Fourteen screws (7%) required intraoperative revision. Screws were removed and repositioned due to a tEMG response < 13 mA, tactile feedback, and 3D fluoroscopic assessment. All screws were revised using the SpineMask with the same screw placement technique. The highest proportion of revisions occurred with Wiltse incisions (4/12, 33%) as this caused the greatest degree of SpineMask deformation, followed by a mini midline incision (3/26, 12%). Percutaneous screws via a single stab incision resulted in the fewest revisions (7/166, 4%). Postoperative CT demonstrated 7 pedicle screw breaches (3%; 5 lateral, 1 medial, 1 superior), all with percutaneous stab incisions (7/166, 4%). The radiological accuracy of the SpineMask tracker was 97% (197/204 screws). No patients suffered neural injury or required postoperative screw revision. CONCLUSIONS The noninvasive cutaneous SpineMask tracker with 3D image guidance and tEMG monitoring provided high accuracy (97%) for percutaneous pedicle screw placement via stab incisions without K-wires.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

PubMed

Dai, Jian; Katoh, Osamu; Kyo, Eisho; Tsuji, Takafumi; Watanabe, Satoshi; Ohya, Hidefumi

2013-10-01

Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success. © 2013, Wiley Periodicals, Inc.

Commercial and Industrial Wiring. Second Edition.

ERIC Educational Resources Information Center

Kaltwasser, Stan; Flowers, Gary

This guide is designed to assist teachers conducting a course to prepare students for entry-level employment in the commercial and industrial wiring trade. Included in the guide are 15 instructional units and the following sections of information for teachers: guidelines in using the unit components; academic and workplace skills classifications…

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.

Bending stiffness of catheters and guide wires.

PubMed

Wünsche, P; Werner, C; Bloss, P

2002-01-01

An important property of catheters and guide wires to assess their pushability behavior is their bending stiffness. To measure bending stiffness, a new bending module with a new clamping device was developed. This module can easily be mounted in commercially available tensile testing equipment, where bending force and deflection due to the bending force can be measured. To achieve high accuracy for the bending stiffness, the bending distance has to be measured with even higher accuracy by using a laser-scan micrometer. Measurement results of angiographic catheters and guide wires were presented and discussed. The bending stiffness shows a significant dependence on the angle of the test specimen's rotation around its length axis.

Eder Puestow dilatation of benign rectal stricture following anterior resection.

PubMed

Woodward, A; Tydeman, G; Lewis, M H

1990-01-01

Benign anastomotic stricture following anterior resection can be difficult to manage when the stricture is proximal. The acceptable surgical options are either a redo low resection with its accompanying hazards or, alternatively, the formation of a permanent colostomy. Although dilatation of such strictures is possible by blind passage of metal bougies, the authors believe that this technique must be regarded as hazardous. A technique of dilatation is described that is usually reserved for esophageal stricture, namely, Eder Puestow dilatation over a guide wire inserted under direct vision. Although this technique may not be without risk, this readily available equipment may be valuable in making a further resection unnecessary.

Residential Wiring. Teacher Edition [and] Student Edition. Third Edition.

ERIC Educational Resources Information Center

Taylor, Mark; Batson, Larry; Carroll, Charles; Ipock, Dan; Leak, Lester; Onstott, Todd

This revised curriculum guide for teachers and students is designed to help prepare students for entry-level employment in the residential wiring trade. The curriculum guide contains six units that cover the following topics: (1) blueprint reading and load calculations; (2) service; (3) rough-in; (4) trim out and troubleshooting; (5) low voltage…

General Construction Trades. Volume 2. Teacher's Guide.

ERIC Educational Resources Information Center

East Texas State Univ., Commerce. Occupational Curriculum Lab.

Twenty-one general construction units are presented in this teacher's guide. The units are organized as follow: concrete finishing-two units (e.g., site preparation, pouring and finishing); plumbing-five units (e.g., pipe joints, angles, and flow; fixtures and valves); electrical wiring-five units (e.g., wiring procedures, planning a layout);…

Commercial and Industrial Wiring. Teacher Edition [and] Student Edition. Third Edition.

ERIC Educational Resources Information Center

Kaltwasser, Stan; Flowers, Gary; Aneke, Norbert O.

This revised curriculum guide for teachers and students includes the additional technical knowledge and applications required to help prepare students for job entry in the commercial and industrial wiring trade. The curriculum guide contains 16 units that cover the following topics: (1) blueprint reading and load calculations; (2) tools and…

Industrial Education. Electricity/Electronics Curriculum Guide, Phase II. Instructional Modules, Level I (9 Week).

ERIC Educational Resources Information Center

Lillo, Robert E.; Soffiotto, Nicholas S.

Designed for students in grades 7 and 8, this electricity/electronics curriculum guide contains instructional modules for ten units of instruction (nine-week class): (1) orientation; (2) understanding electricity; (3) safety; (4) methods to generate electricity; (5) wiring tools and wire; (6) soldering; (7) magnetism and electromagnetism; (8)…

Industrial Education. Electricity/Electronics Curriculum Guide, Phase II. Instructional Modules, Level I (18 Week).

ERIC Educational Resources Information Center

Lillo, Robert E.; Soffiotto, Nicholas S.

Designed for students in grades 7 and 8, this electricity/electronics curriculum guide contains instructional modules for twelve units of instruction: (1) orientation; (2) understanding electricity; (3) safety; (4) methods to generate electricity; (5) wiring tools and wire; (6) soldering; (7) magnetism and electromagnetism; (8) circuits, symbols,…

Fluoroscopically guided closed reduction and internal fixation of fractures of the lateral portion of the humeral condyle: prospective clinical study of the technique and results in ten dogs.

PubMed

Cook, J L; Tomlinson, J L; Reed, A L

1999-01-01

To report a technique for fluoroscopically guided closed reduction with internal fixation of fractures of the lateral portion of the humeral condyle (FLHC) and determine the long-term results in 10 clinical cases. Prospective clinical case study. Ten dogs with 11 fractures. Fractures of the lateral portion of the humeral condyle were stabilized with transcondylar screws and Kirschner wires. Closed reduction and implant placement were achieved using intraoperative fluoroscopic guidance. After fracture repair, postoperative radiographs were evaluated for articular alignment and implant placement. Dogs were evaluated after surgery by means of lameness scores, elbow range of motion (ROM), radiographic assessment, and owner evaluation of function. Postoperative reduction was considered anatomic in 6 fractures with all other fractures having <1.5 mm of malreduction. Follow-up was available for 9 patients from 9 to 21 months after surgery. All of the fractures had healed. One minor (wire migration) and one major (implant failure) complication occurred. Mean lameness scores were 0 (n = 6), 0.5 (n = 2), and 1 (n = 1) at the time of final follow-up. No significant differences were found in follow-up ROM values between affected and unaffected elbows. All of the dogs in this study regained 90-100% of full function, based on owner assessment. Fluoroscopic guidance for closed reduction and internal fixation of FLHC in dogs is an effective technique.

MRI-guided Wire Localization Surgical Biopsy in an Adolescent Patient with a Difficult to Diagnose Case of Lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Scott M., E-mail: Thompson.scott@mayo.edu; Gorny, Krzysztof R.; Jondal, Danielle E.

A 17-year-old previously healthy female presented with a progressive soft tissue infiltrative process involving the neck and thorax. Extensive diagnostic evaluation including multiple imaging, laboratory, and biopsy studies was nondiagnostic. Due to an urgent need to establish a diagnosis and several previous nondiagnostic biopsies, she was referred to interventional radiology for MRI-guided wire localization immediately prior to open surgical biopsy. Under general anesthesia, wires were placed in the areas of increased T2 signal within the bilateral splenius capitis muscles using intermittent MRI-guidance followed by immediate surgical biopsy down to the wires. Pathology confirmed the diagnosis of diffuse large B-cell lymphoma.

A Hybrid Reality Radiation-free Simulator for Teaching Wire Navigation Skills

PubMed Central

Kho, Jenniefer Y.; Johns, Brian D.; Thomas, Geb. W.; Karam, Matthew D.; Marsh, J. Lawrence; Anderson, Donald D.

2016-01-01

Objectives Surgical simulation is an increasingly important method to facilitate the acquiring of surgical skills. Simulation can be helpful in developing hip fracture fixation skills because it is a common procedure for which performance can be objectively assessed (i.e., the tip-apex distance). The procedure requires fluoroscopic guidance to drill a wire along an osseous trajectory to a precise position within bone. The objective of this study was to assess the construct validity for a novel radiation-free simulator designed to teach wire navigation skills in hip fracture fixation. Methods Novices (N=30) with limited to no surgical experience in hip fracture fixation and experienced surgeons (N=10) participated. Participants drilled a guide wire in the center-center position of a synthetic femoral head in a hip fracture simulator, using electromagnetic sensors to track the guide wire position. Sensor data were gathered to generate fluoroscopic-like images of the hip and guide wire. Simulator performance of novice and experienced participants was compared to measure construct validity. Results The simulator was able to discriminate the accuracy in guide wire position between novices and experienced surgeons. Experienced surgeons achieved a more accurate tip-apex distance than novices (13 vs 23 mm, respectively, p=0.009). The magnitude of improvement on successive simulator attempts was dependent on level of expertise; tip-apex distance improved significantly in the novice group, while it was unchanged in the experienced group. Conclusions This hybrid reality, radiation-free hip fracture simulator, which combines real-world objects with computer-generated imagery demonstrates construct validity by distinguishing the performance of novices and experienced surgeons. There is a differential effect depending on level of experience, and it could be used as an effective training tool in novice surgeons. PMID:26165262

Mountain Plains Learning Experience Guide: Electrical Wiring. Course: Electrical Wiring Rough-In.

ERIC Educational Resources Information Center

Arneson, R.; And Others

One of two individualized courses included in an electrical wiring curriculum, this course covers electrical installations that are generally hidden within the structure. The course is comprised of four units: (1) Outlet and Switch Boxes, (2) Wiring, (3) Service Entrance, and (4) Signal and Low Voltage Systems. Each unit begins with a Unit…

[Percutaneous tracheotomy].

PubMed

Paleczny, J; Maciejewski, D; Łoniewska-Paleczny, E; Sawczuk, M; Kaczur, A

2000-01-01

The purpose of this study was to compare on the basis of up to date papers currently applied methods of the percutaneous tracheostomy (PT). There are four main PT methods by: Ciaglia, Schachner, Griggs and Fantoni. In these methods a wire is introduced into the trachea serving as a guide for special forceps or series of dilatators of increasing diameter to dilate the wall and allow cannulation of the trachea. In the literature authors found a low incidence of complications after PT. Acute complications were documented in 6-18% and late complications in 1-3% of the patients. Follow-up showed no late obstructive complications at the level of stomia and very low (0.3-0.36%) mortality risk. Translaryngeal tracheostomy (TLT) by Fantoni ensures minimal risk of complications and tissue trauma. In the TLT method through a needle inserted in to the trachea a guide wire is retrogradely pushed out of the mouth and attached to special flexible tracheostomy tube by flexible plastic cone with pointed metal tip. This device is then pulled back through larynx and outwards across the trachea and neck wall by traction on the wire. TLT can also be used in infants and children and in difficult patients in whom other techniques are riskier Review of the literature suggests that the PT can be safe and also cost-effective for properly selected patients in intensive care and other hospital units.

A Kirschner wire as a transverse-axis guide to improve acetabular cup positioning.

PubMed

Ishidou, Y; Hirotsu, M; Setoguchi, T; Nagano, S; Kakoi, H; Yokouchi, M; Yamamoto, T; Komiya, S

2016-04-01

To compare cup-positioning accuracy in total hip arthroplasty (THA) with or without use of a Kirschner wire as a transverse-axis guide for pelvic alignment. Records of 18 men and 73 women (mean age, 60 years) who underwent primary THA with (n=49) or without (n=42) use of a Kirschner wire as a transverse-axis guide for pelvic alignment were reviewed. A 2.4-mm Kirschner wire as a transversea-xis guide was inserted to the anterior superior iliac spine and was parallel to a line linking the left and right anterior superior iliac spine. The safe zone for cup positioning was defined as 30º to 50° abduction and 10º to 30º anteversion. Of the 5 operative surgeons, 2 were classified as experienced (total surgical volume >300) and 3 as inexperienced (total surgical volume of <50). The proportion of patients with the cup in the safe zone was compared in patients with or without use of the transverse-axis guide and in experienced and inexperienced surgeons. For inexperienced surgeons, the use of the transverse-axis guide significantly improved the proportion of patients with the cup in the safe zone from 90% to 100% for abduction, from 50% to 82.4% for anteversion, and from 40% to 82.4% for both. Patients with the cup inside or outside the safe zone were comparable in terms of body height, weight, BMI, subcutaneous fat thickness, incision length, and acetabular cup size. The use of the transverse-axis guide improved the accuracy of cup positioning by inexperienced surgeons.

Performance of magnetic field‐guided navigation system for interventional neurosurgical and cardiac procedures

PubMed Central

Chu, James C.H.; Hsi, Wen Chien; Hubbard, Lincoln; Zhang, Yunkai; Bernard, Damian; Reeder, Pamela; Lopes, Demetrius

2005-01-01

A hospital‐based magnetic guidance system (MGS) was installed to assist a physician in navigating catheters and guide wires during interventional cardiac and neurosurgical procedures. The objective of this study is to examine the performance of this magnetic field‐guided navigation system. Our results show that the system's radiological imaging components produce images with quality similar to that produced by other modern fluoroscopic devices. The system's magnetic navigation components also deflect the wire and catheter tips toward the intended direction. The physician, however, will have to oversteer the wire or catheter when defining the steering angle during the procedure. The MGS could be clinically useful in device navigation deflection and vessel access. PACS numbers: 07.55.Db, 07.85.‐m PMID:16143799

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head

PubMed Central

Wang, Wei; Hu, Wei; Yang, Pei; Dang, Xiao Qian; Li, Xiao Hui; Wang, Kun Zheng

2017-01-01

Introduction Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests. Methods Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target). Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT). A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy. Results The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm. Conclusions Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis. PMID:28464029

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head.

PubMed

Wang, Wei; Hu, Wei; Yang, Pei; Dang, Xiao Qian; Li, Xiao Hui; Wang, Kun Zheng

2017-01-01

Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests. Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target). Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT). A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy. The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm. Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis.

Leading the Wired Organization: The Information Professional's Guide to Managing Technological Change.

ERIC Educational Resources Information Center

Stover, Mark

This book explains through descriptive narrative, illustrative examples, and practical suggestions how today's information specialists can navigate in the new "wired" organizations. The emphasis is on practical, useful, relevant advice. The following ten chapters are included: (1) "Communicating Online: The Heart of the Wired Organization"…

Basic Electricity. Part 4.

ERIC Educational Resources Information Center

Kilmer, Donald C.

Designed for the student interested in a vocation in electrical work, this guide, fourth in a set of four, includes three units: Unit X--Splicing Wires, covering thirteen lessons (removing insulation, pigtail splice, Western Union splice, tap splice, extension cord splice, connecting wires to a terminal screw, underwriter's knot, three-wire ground…

Magnetic navigation system assisted percutaneous coronary intervention: a comparison to the conventional approach in daily practice.

PubMed

Li, Chun-Jian; Wang, Hui; Yang, Zhi-Jian; Cao, Ke-Jiang

2011-01-01

The benefits of the magnetic navigation system (MNS) for percutaneous coronary intervention (PCI) remain unclear, and a comparison of the MNS assisted approach to the conventional approach for PCI, when used in daily practice, is little studied. This study aimed to investigate the benefits of an MNS assisted technique as compared to the conventional technique for PCI. Forty-eight consecutive patients scheduled for PCI were recruited between December 2009 and April 2010. MNS assisted PCIs were performed on 54 target vessels. Another 45 patients with 54 target vessels undergoing conventional PCIs were selected from a historical population of patients to match the MNS group according to the coronary lesion type (ACC/AHA classification). Emergency PCIs and chronic total occlusions were excluded from both groups. Analyses were performed using Stata 9.2 statistical software. There were no significant differences between the baseline characteristics of the MNS group and the control group. The success rates were 100.0% for the MNS assisted PCI and 98.1% for the conventional PCI, which did not reach a significant difference (P = 1.000); there were also no significant differences in terms of guide wire crossing time ((51.7 ± 30.5) seconds vs. (57.5 ± 49.4) seconds, P = 0.448), operation time ((28.4 ± 15.9) minutes vs. (28.0 ± 24.7) minutes, P = 0.935), X-ray exposure ((458.1 ± 350.1) µGym(2) vs. (558.7 ± 451.7) µGym(2), P = 0.197; and (94.2 ± 80.9) mGy vs. (96.2 ± 77.3) mGy, P = 0.895) or contrast usage ((7.3 ± 4.0) ml vs. (6.1 ± 3.7) ml, P = 0.121) between the two groups. However, a trend toward shorter guide wire crossing time and less X-ray exposure were observed for the magnetic group. In daily practice, MNS assisted PCI resulted in a similar procedural success rate, operation time, and contrast usage, with a trend toward shorter guide wire crossing time and less X-ray exposure when compared to the conventional PCI.

A low-cost, manufacturable method for fabricating capillary and optical fiber interconnects for microfluidic devices.

PubMed

Hartmann, Daniel M; Nevill, J Tanner; Pettigrew, Kenneth I; Votaw, Gregory; Kung, Pang-Jen; Crenshaw, Hugh C

2008-04-01

Microfluidic chips require connections to larger macroscopic components, such as light sources, light detectors, and reagent reservoirs. In this article, we present novel methods for integrating capillaries, optical fibers, and wires with the channels of microfluidic chips. The method consists of forming planar interconnect channels in microfluidic chips and inserting capillaries, optical fibers, or wires into these channels. UV light is manually directed onto the ends of the interconnects using a microscope. UV-curable glue is then allowed to wick to the end of the capillaries, fibers, or wires, where it is cured to form rigid, liquid-tight connections. In a variant of this technique, used with light-guiding capillaries and optical fibers, the UV light is directed into the capillaries or fibers, and the UV-glue is cured by the cone of light emerging from the end of each capillary or fiber. This technique is fully self-aligned, greatly improves both the quality and the manufacturability of the interconnects, and has the potential to enable the fabrication of interconnects in a fully automated fashion. Using these methods, including a semi-automated implementation of the second technique, over 10,000 interconnects have been formed in almost 2000 microfluidic chips made of a variety of rigid materials. The resulting interconnects withstand pressures up to at least 800psi, have unswept volumes estimated to be less than 10 femtoliters, and have dead volumes defined only by the length of the capillary.

Pressure-wire-guided percutaneous transluminal pulmonary angioplasty: a breakthrough in catheter-interventional therapy for chronic thromboembolic pulmonary hypertension.

PubMed

Inami, Takumi; Kataoka, Masaharu; Shimura, Nobuhiko; Ishiguro, Haruhisa; Yanagisawa, Ryoji; Fukuda, Keiichi; Yoshino, Hideaki; Satoh, Toru

2014-11-01

This study sought to prove the safety and effectiveness of pressure-wire-guided percutaneous transluminal pulmonary angioplasty (PTPA). PTPA has been demonstrated to be effective for treatment of chronic thromboembolic pulmonary hypertension. However, a major and occasionally fatal complication after PTPA is reperfusion pulmonary edema. To avoid this, we developed the PEPSI (Pulmonary Edema Predictive Scoring Index). The pressure wire has been used to detect insufficiency of flow in a vessel. We included 350 consecutive PTPA sessions in 103 patients with chronic thromboembolic pulmonary hypertension from January 1, 2009 to December 31, 2013. During these 5 years, 140 PTPA sessions were performed without guidance, 65 with guidance of PEPSI alone, and 145 with both PEPSI and pressure-wire guidance. Each PTPA session was finished after achieving PEPSI scores of <35.4 with PEPSI guidance and each target lesion achieving distal mean pulmonary arterial pressure <35 mm Hg with pressure-wire guidance. The occurrence of clinically critical reperfusion pulmonary edema and vessel injuries were lowest in the group using the guidance of both pressure wire and PEPSI (0% and 6.9%, respectively). Furthermore, the group guided by pressure wire and PEPSI accomplished the same hemodynamic improvements with fewer numbers of target lesions treated and sessions performed. The combined approach using pressure wire and PEPSI produced more efficient clinical results and greatly reduced reperfusion pulmonary edema and vessel complications. This is further evidence that PTPA is an alternative strategy for treating chronic thromboembolic pulmonary hypertension. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

CT fluoroscopy-guided preoperative short hook wire placement for small pulmonary lesions: evaluation of safety and identification of risk factors for pneumothorax.

PubMed

Iguchi, Toshihiro; Hiraki, Takao; Gobara, Hideo; Fujiwara, Hiroyasu; Matsui, Yusuke; Miyoshi, Shinichiro; Kanazawa, Susumu

2016-01-01

To retrospectively evaluate the safety of computed tomography (CT) fluoroscopy-guided short hook wire placement for video-assisted thoracoscopic surgery and the risk factors for pneumothorax associated with this procedure. We analyzed 267 short hook wire placements for 267 pulmonary lesions (mean diameter, 9.9 mm). Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for pneumothorax. Complications (219 grade 1 and 4 grade 2 adverse events) occurred in 196 procedures. No grade 3 or above adverse events were observed. Univariate analysis revealed increased vital capacity (odds ratio [OR], 1.518; P = 0.021), lower lobe lesion (OR, 2.343; P =0.001), solid lesion (OR, 1.845; P = 0.014), prone positioning (OR, 1.793; P = 0.021), transfissural approach (OR, 11.941; P = 0.017), and longer procedure time (OR, 1.036; P = 0.038) were significant predictors of pneumothorax. Multivariate analysis revealed only the transfissural approach (OR, 12.171; P = 0.018) and a longer procedure time (OR, 1.048; P = 0.012) as significant independent predictors. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occurred, but all complications were minor. A transfissural approach and longer procedure time were significant independent predictors of pneumothorax. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occur. Complications are usually minor and asymptomatic. A transfissural approach and longer procedure time are significant independent predictors of pneumothorax.

A haptic device for guide wire in interventional radiology procedures.

PubMed

Moix, Thomas; Ilic, Dejan; Bleuler, Hannes; Zoethout, Jurjen

2006-01-01

Interventional Radiology (IR) is a minimally invasive procedure where thin tubular instruments, guide wires and catheters, are steered through the patient's vascular system under X-ray imaging. In order to perform these procedures, a radiologist has to be trained to master hand-eye coordination, instrument manipulation and procedure protocols. The existing simulation systems all have major drawbacks: the use of modified instruments, unrealistic insertion lengths, high inertia of the haptic device that creates a noticeably degraded dynamic behavior or excessive friction that is not properly compensated for. In this paper we propose a quality training environment dedicated to IR. The system is composed of a virtual reality (VR) simulation of the patient's anatomy linked to a robotic interface providing haptic force feedback. This paper focuses on the requirements, design and prototyping of a specific haptic interface for guide wires.

The impact of wire caliber on ERCP outcomes: a multicenter randomized controlled trial of 0.025-inch and 0.035-inch guidewires.

PubMed

Bassan, Milan S; Sundaralingam, Praka; Fanning, Scott B; Lau, James; Menon, Jayaram; Ong, Evan; Rerknimitr, Rungsun; Seo, Dong-Wan; Teo, Eng Kiong; Wang, Hsiu-Po; Reddy, D Nageshwar; Goh, Khean Lee; Bourke, Michael J

2018-06-01

Wire-guided biliary cannulation has been demonstrated to improve cannulation rates and reduce post-ERCP pancreatitis (PEP), but the impact of wire caliber has not been studied. This study compares successful cannulation rates and ERCP adverse events by using a 0.025-inch and 0.035-inch guidewire. A randomized, single blinded, prospective, multicenter trial at 9 high-volume tertiary-care referral centers in the Asia-Pacific region was performed. Patients with an intact papilla and conventional anatomy who did not have malignancy in the head of the pancreas or ampulla and were undergoing ERCP were recruited. ERCP was performed by using a standardized cannulation algorithm, and patients were randomized to either a 0.025-inch or 0.035-inch guidewire. The primary outcomes of the study were successful wire-guided cannulation and the incidence of PEP. Overall successful cannulation and ERCP adverse events also were studied. A total of 710 patients were enrolled in the study. The primary wire-guided biliary cannulation rate was similar in 0.025-inch and 0.035-inch wire groups (80.7% vs 80.3%; P = .90). The rate of PEP between the 0.025-inch and the 0.035-inch wire groups did not differ significantly (7.8% vs 9.3%; P = .51). No differences were noted in secondary outcomes. Similar rates of successful cannulation and PEP were demonstrated in the use of 0.025-inch and 0.035-inch guidewires. (Clinical trial registration number: NCT01408264.). Copyright © 2018. Published by Elsevier Inc.

Investigation of the interwire energy transfer of elastic guided waves inside prestressed cables.

PubMed

Treyssède, Fabien

2016-07-01

Elastic guided waves are of interest for the non-destructive evaluation of cables. Cables are most often multi-wire structures, and understanding wave propagation requires numerical models accounting for the helical geometry of individual wires, the interwire contact mechanisms and the effects of prestress. In this paper, a modal approach based on a so-called semi-analytical finite element method and taking advantage of a biorthogonality relation is proposed in order to calculate the forced response under excitation of a cable, multi-wired, twisted, and prestressed. The main goal of this paper is to investigate how the energy transfers from a given wire, directly excited, to the other wires in order to identify some localization of energy inside the active wire as the waves propagate along the waveguide. The power flow of the excited field is theoretically derived and an energy transfer parameter is proposed to evaluate the level of energy localization inside a given wire. Numerical results obtained for different polarizations of excitation, central and peripheral, highlight how the energy may localize, spread, or strongly change in the cross-section as waves travel along the axis. In particular, a compressional mode localized inside the central wire is found, with little dispersion and significant excitability.

Procedures for precap visual inspection

NASA Technical Reports Server (NTRS)

1984-01-01

Screening procedures for the final precap visual inspection of microcircuits used in electronic system components are described as an aid in training personnel unfamiliar with microcircuits. Processing techniques used in industry for the manufacture of monolithic and hybrid components are presented and imperfections that may be encountered during this inspection are discussed. Problem areas such as scratches, voids, adhesions, and wire bonding are illustrated by photomicrographs. This guide can serve as an effective tool in training personnel to perform precap visual inspections efficiently and reliably.

Entrapment of guide-wire during oesophageal dilation.

PubMed

Misra, S P; Dwivedi, M

1997-01-01

We report a patient who developed oesophageal stricture after accidental ingestion of acid. During one of the oesophageal dilation sessions, a Savary-Gillard guide-wire got entrapped in the stomach and had to be removed surgically. A Foley catheter, placed for feeding purposes, migrated into the proximal small intestine causing acute intestinal obstruction. The balloon of the Foley catheter had to be punctured using a sclerotherapy needle and the catheter withdrawn.

Silicon sensors for catheters and guide wires

NASA Astrophysics Data System (ADS)

Goosen, Hans F.

2001-11-01

One area that can make use of the miniature size of present day micro electromechanical systems (MEMS) is that of the medical field of minimally invasive interventions. These procedures, used for both diagnosis and treatment, use catheters that are advanced through the blood vessels deep into the body, without the need for surgery. However, once inside the body, the doctor performing the procedure is completely reliant on the information the catheter(s) can provide in addition to the projection imaging of a fluoroscope. A good range of sensors for catheters is required for a proper diagnosis. To this end, miniature sensors are being developed to be fitted to catheters and guide wires. As the accurate positioning of these instruments is problematic, it is necessary to combine several sensors on the same guide wire or catheter to measure several parameters in the same location. This however, brings many special problems to the design of the sensors, such as small size, low power consumption, bio-compatibility of materials, robust design for patient safety, a limited number of connections, packaging, etc. This paper will go into both the advantages and design problems of micromachined sensors and actuators in catheters and guide wires. As an example, a multi parameter blood sensor, measuring flow velocity, pressure and oxygen saturation, will be discussed.

Orbital atherectomy as an adjunct to debulk difficult calcified lesions prior to mesenteric artery stenting.

PubMed

Manunga, Jesse M; Oderich, Gustavo S

2012-08-01

To describe a technique in which percutaneous orbital atherectomy is used to debulk heavily calcified superior mesenteric artery (SMA) occlusions as an adjunct in patients undergoing angioplasty and stenting. The technique is demonstrated in a 62-year-old woman with a replaced right hepatic artery originating from an SMA occluded by densely calcified lesions. Via a left transbrachial approach, a 7-F MPA guide catheter was used to engage the ostium of the SMA, which was crossed using a catheter and guidewire. The calcified lesion was debulked using the 2-mm Diamondback 360° orbital atherectomy system. The wire was exchanged for a 0.014-inch filter wire and 0.018-inch guidewire. Using a 2-guidewire technique, the SMA was stented with a self-expanding stent for the distal lesion that crossed side branches and a balloon-expandable stent at the ostium. A 0.014-inch guidewire was placed into the replaced hepatic artery through a cell of the self-expanding stent, followed by deployment of a small balloon-expandable stent to address the residual lesion. The use of orbital atherectomy to debulk occluded and heavily calcified SMA lesions may optimize the technical results with angioplasty and stenting.

Advanced high temperature static strain sensor development

NASA Technical Reports Server (NTRS)

Hulse, C. O.; Stetson, K. A.; Grant, H. P.; Jameikis, S. M.; Morey, W. W.; Raymondo, P.; Grudkowski, T. W.; Bailey, R. S.

1986-01-01

An examination was made into various techniques to be used to measure static strain in gas turbine liners at temperatures up to 1150 K (1600 F). The methods evaluated included thin film and wire resistive devices, optical fibers, surface acoustic waves, the laser speckle technique with a heterodyne readout, optical surface image and reflective approaches and capacitive devices. A preliminary experimental program to develop a thin film capacitive device was dropped because calculations showed that it would be too sensitive to thermal gradients. In a final evaluation program, the laser speckle technique appeared to work well up to 1150 K when it was used through a relatively stagnant air path. The surface guided acoustic wave approach appeared to be interesting but to require too much development effort for the funds available. Efforts to develop a FeCrAl resistive strain gage system were only partially successful and this part of the effort was finally reduced to a characterization study of the properties of the 25 micron diameter FeCrAl (Kanthal A-1) wire. It was concluded that this particular alloy was not suitable for use as the resistive element in a strain gage above about 1000 K.

Advanced high temperature static strain sensor development

NASA Astrophysics Data System (ADS)

Hulse, C. O.; Stetson, K. A.; Grant, H. P.; Jameikis, S. M.; Morey, W. W.; Raymondo, P.; Grudkowski, T. W.; Bailey, R. S.

1986-08-01

An examination was made into various techniques to be used to measure static strain in gas turbine liners at temperatures up to 1150 K (1600 F). The methods evaluated included thin film and wire resistive devices, optical fibers, surface acoustic waves, the laser speckle technique with a heterodyne readout, optical surface image and reflective approaches and capacitive devices. A preliminary experimental program to develop a thin film capacitive device was dropped because calculations showed that it would be too sensitive to thermal gradients. In a final evaluation program, the laser speckle technique appeared to work well up to 1150 K when it was used through a relatively stagnant air path. The surface guided acoustic wave approach appeared to be interesting but to require too much development effort for the funds available. Efforts to develop a FeCrAl resistive strain gage system were only partially successful and this part of the effort was finally reduced to a characterization study of the properties of the 25 micron diameter FeCrAl (Kanthal A-1) wire. It was concluded that this particular alloy was not suitable for use as the resistive element in a strain gage above about 1000 K.

Monorail snare technique for the recovery of stretched platinum coils: technical case report.

PubMed

Fiorella, David; Albuquerque, Felipe C; Deshmukh, Vivek R; McDougall, Cameron G

2005-07-01

Coil stretching represents a potentially hazardous technical complication not infrequently encountered during the embolization of cerebral aneurysms. Often, the stretched coil cannot be advanced into the aneurysm or withdrawn intact. The operator is then forced to attempt to retract the damaged coil, which may result in coil breakage, leaving behind a significant length of potentially thrombogenic stretched coil material within the parent vessel. To overcome this problem, we devised a technique to snare the distal, unstretched, intact portion of the platinum coil by use of the indwelling microcatheter and stretched portion of the coil as a monorail guide. We have used this technique successfully in four patients to snare coils stretched during cerebral aneurysm embolization. Three of these patients were undergoing Neuroform (Boston Scientific/Target, Fremont, CA) stent-supported coil embolization of unruptured aneurysms. In all cases, the snare was advanced easily to the targeted site for coil engagement by use of the microcatheter as a monorail guide. Once the intact distal segment of the coil was ensnared, coil removal was uneventful, with no disturbance of the remainder of the indwelling coil pack or Neuroform stent. A 2-mm Amplatz Goose Neck microsnare (Microvena Corp., White Bear Lake, MN) was placed through a Prowler-14 microcatheter (Cordis Corp., Miami, FL). The hub of the indwelling SL-10 microcatheter (Boston Scientific, Natick, MA) was then cut away with a scalpel, leaving the coil pusher wire intact, and removed. The open 2-mm snare was then advanced over the outside of the coil pusher wire and microcatheter. The snare and Prowler-14 microcatheter were then advanced into the guiding catheter (6- or 7-French) as a unit over the indwelling SL-10 microcatheter. By use of the SL-10 microcatheter and coil as a "monorail" guide, the snare was advanced over and beyond the microcatheter and the stretched portion of the coil until the snare was in position to engage the distal unstretched coil. At this point, the snare was then closed around the intact portion of the coil, and the microcatheters, snare, and coil were removed as a unit. The monorail snare technique represents a fast, safe, and easy method by which a stretched coil can be removed.

Advances in Procedural Techniques - Antegrade

PubMed Central

Wilson, William; Spratt, James C.

2014-01-01

There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the “hybrid’ approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited “interventional” collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

Initial experience with a dedicated coronary re-entry device for revascularization of chronic total occlusions.

PubMed

Whitlow, Patrick L; Lombardi, William L; Araya, Mario; Michael Wyman, R; Torres, Humberto; Dauvergne, Christian; Tsuchikane, Etsuo; Lansky, Alexandra; Thompson, Craig A

2012-11-01

The aim of this registry was to evaluate a new device designed to facilitate antegrade guidewire re-entry into the true lumen of a chronic total coronary occlusion (CTO) from the adjacent subintimal space. Successful recanalization of CTOs results in clinical improvement in appropriately selected patients. CTO intervention is time- and resource-consuming, and a simplified approach enabling antegrade guidewire re-entry into the distal true lumen might improve success. Patients with CTO and ischemia were entered into a prospective registry regardless of lesion characteristics. If wire manipulation resulted in subintimal wire entrapment, a new re-entry tool (a 2.5-mm flat subintimal balloon with two exit ports offset by 180°) was used as a platform to attempt guidewire penetration into the distal true lumen. The primary endpoint assessed was successful device-guided re-entry. Standard techniques were then utilized to open the CTO. In 40 consecutive CTO lesions attempted, 19 resulted in subintimal wire entrapment (mean occlusion length 44 mm). Sixteen of these 19 were successfully crossed with an antegrade guidewire into the distal true lumen using the new device (84%). One patient with unsuccessful re-entry was subsequently recanalized with a retrograde technique. All crossed lesions were stented (17/17), resulting in TIMI 3 flow without major complications. Two cases were unsuccessful. One patient had a grade I coronary perforation requiring no treatment. A new device to recanalize CTOs complicated by subintimal wire entrapment can be used successfully by experienced operators. Further study of this coronary re-entry device is ongoing. Copyright © 2011 Wiley Periodicals, Inc.

Implementing Cleaner Printed Wiring Board Technologies: Surface Finishes

EPA Pesticide Factsheets

This document describes the problems, solutions, and time and effort involved in implementing alternative surface finish technologies, and this guide is produced as part of the DfE Printed Wiring Board Project

Intraoperative fluoroscopic evaluation of screw placement during pelvic and acetabular surgery.

PubMed

Yi, Chengla; Burns, Sean; Hak, David J

2014-01-01

The surgical treatment of pelvic and acetabular fractures can be technically challenging. Various techniques are available for the reconstruction of pelvic and acetabular fractures. Less invasive percutaneous fracture stabilization techniques, with closed reduction or limited open reduction, have been developed and are gaining popularity in the management of pelvic and acetabular fractures. These techniques require knowledge and interpretation of various fluoroscopic images to ensure appropriate and safe screw placement. Given the anatomic complexity of the intrapelvic structures and the 2-dimensional nature of standard fluoroscopy, multiple images oriented in different planes are needed to assess the accuracy of guide wire and screw placement. This article reviews the fluoroscopic imaging of common screw orientations during pelvic and acetabular surgery.

Wire inhomogeneity detector having a core with opposing pole pieces and guide pieces adjacent the opposing pole pieces

DOEpatents

Gibson, George H.; Smits, Robert G.; Eberhard, Philippe H.

1989-01-01

A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Separate vertical wiring for the fixation of comminuted fractures of the inferior pole of the patella.

PubMed

Song, Hyung Keun; Yoo, Je Hyun; Byun, Young Soo; Yang, Kyu Hyun

2014-05-01

Among patients over 50 years of age, separate vertical wiring alone may be insufficient for fixation of fractures of the inferior pole of the patella. Therefore, mechanical and clinical studies were performed in patients over the age of 50 to test the strength of augmentation of separate vertical wiring with cerclage wire (i.e., combined technique). Multiple osteotomies were performed to create four-part fractures in the inferior poles of eight pairs of cadaveric patellae. One patella from each pair was fixed with the separate wiring technique, while the other patella was fixed with a combined technique. The ultimate load to failure and stiffness of the fixation were subsequently measured. In a clinical study of 21 patients (average age of 64 years), comminuted fractures of the inferior pole of the patellae were treated using the combined technique. Operative parameters were recorded from which post-operative outcomes were evaluated. For cadaveric patellae, whose mean age was 69 years, the mean ultimate loads to failure for the separate vertical wiring technique and the combined technique were 216.4±72.4 N and 324.9±50.6 N, respectively (p=0.012). The mean stiffness for the separate vertical wiring technique and the combined technique was 241.1±68.5 N/mm and 340.8±45.3 N/mm, respectively (p=0.012). In the clinical study, the mean clinical score at final follow-up was 28.1 points. Augmentation of separate vertical wiring with cerclage wire provides enough strength for protected early exercise of the knee joint and uneventful healing.

Numerical and Experimental Study of Wake Redirection Techniques in a Boundary Layer Wind Tunnel

NASA Astrophysics Data System (ADS)

Wang, J.; Foley, S.; Nanos, E. M.; Yu, T.; Campagnolo, F.; Bottasso, C. L.; Zanotti, A.; Croce, A.

2017-05-01

The aim of the present paper is to validate a wind farm LES framework in the context of two distinct wake redirection techniques: yaw misalignment and individual cyclic pitch control. A test campaign was conducted using scaled wind turbine models in a boundary layer wind tunnel, where both particle image velocimetry and hot-wire thermo anemometers were used to obtain high quality measurements of the downstream flow. A LiDAR system was also employed to determine the non-uniformity of the inflow velocity field. A high-fidelity large-eddy simulation lifting-line model was used to simulate the aerodynamic behavior of the system, including the geometry of the wind turbine nacelle and tower. A tuning-free Lagrangian scale-dependent dynamic approach was adopted to improve the sub-grid scale modeling. Comparisons with experimental measurements are used to systematically validate the simulations. The LES results are in good agreement with the PIV and hot-wire data in terms of time-averaged wake profiles, turbulence intensity and Reynolds shear stresses. Discrepancies are also highlighted, to guide future improvements.

Minimally invasive tension band wiring technique for olecranon fractures.

PubMed

Takada, Naoya; Kato, Kenji; Fukuta, Makoto; Wada, Ikuo; Otsuka, Takanobu

2013-12-01

Some types of implants, such as plates, screws, wires, and nails, have been used for open reduction and internal fixation of olecranon fractures. A ≥ 10 cm longitudinal incision is used for open reduction and internal fixation of olecranon fractures. According to previous studies, tension band wiring is a popular method that gives good results. However, back out of the wires after the surgery is one of the main postoperative complications. Moreover, if the Kirschner wires are inserted through the anterior ulnar cortex, they may impinge on the radial neck, supinator muscle, or biceps tendon. Herein, we describe the minimally invasive tension band wiring technique using Ring-Pin. This technique can be performed through a 2 cm incision. Small skin incisions are advantageous from an esthetic viewpoint. Ring-Pin was fixed by using a dedicated cable wire that does not back out unless the cable wire breaks or slips out of the dedicated metallic clamp. As the pins are placed in intramedullary canal, this technique does not lead to postoperative complications that may occur after transcortical fixation by conventional tension band wiring. Minimally invasive tension band wiring is one of the useful options for the treatment of olecranon fractures with some advantages.

Intravascular US-Guided Portal Vein Access: Improved Procedural Metrics during TIPS Creation.

PubMed

Gipson, Matthew G; Smith, Mitchell T; Durham, Janette D; Brown, Anthony; Johnson, Thor; Ray, Charles E; Gupta, Rajan K; Kondo, Kimi L; Rochon, Paul J; Ryu, Robert K

2016-08-01

To evaluate transjugular intrahepatic portosystemic shunt (TIPS) outcomes and procedure metrics with the use of three different image guidance techniques for portal vein (PV) access during TIPS creation. A retrospective review of consecutive patients who underwent TIPS procedures for a range of indications during a 28-month study period identified a population of 68 patients. This was stratified by PV access techniques: fluoroscopic guidance with or without portography (n = 26), PV marker wire guidance (n = 18), or intravascular ultrasound (US) guidance (n = 24). Procedural outcomes and procedural metrics, including radiation exposure, contrast agent volume used, procedure duration, and PV access time, were analyzed. No differences in demographic or procedural characteristics were found among the three groups. Technical success, technical success of the primary planned approach, hemodynamic success, portosystemic gradient, and procedure-related complications were not significantly different among groups. Fluoroscopy time (P = .003), air kerma (P = .01), contrast agent volume (P = .003), and total procedural time (P = .02) were reduced with intravascular US guidance compared with fluoroscopic guidance. Fluoroscopy time (P = .01) and contrast agent volume (P = .02) were reduced with intravascular US guidance compared with marker wire guidance. Intravascular US guidance of PV access during TIPS creation not only facilitates successful TIPS creation in patients with challenging anatomy, as suggested by previous investigations, but also reduces important procedure metrics including radiation exposure, contrast agent volume, and overall procedure duration compared with fluoroscopically guided TIPS creation. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Wire blade development for Fixed Abrasive Slicing Technique (FAST) slicing

NASA Technical Reports Server (NTRS)

Khattak, C. P.; Schmid, F.; Smith, M. B.

1982-01-01

A low cost, effective slicing method is essential to make ingot technology viable for photovoltaics in terrestrial applications. The fixed abrasive slicing technique (FAST) combines the advantages of the three commercially developed techniques. In its development stage FAST demonstrated cutting effectiveness of 10 cm and 15 cm diameter workpieces. Wire blade development is still the critical element for commercialization of FAST technology. Both impregnated and electroplated wire blades have been developed; techniques have been developed to fix diamonds only in the cutting edge of the wire. Electroplated wires show the most near term promise and this approach is emphasized. With plated wires it has been possible to control the size and shape of the electroplating, it is expected that this feature reduces kerf and prolongs the life of the wirepack.

An intravascular loopless monopole antenna for vessel wall MR imaging at 3.0 T.

PubMed

Yuan, Hongyang; Lv, Xing; Ma, Xiaohai; Zhang, Rui; Fu, Youyi; Yang, Xuedong; Wang, Xiaoying; Zhang, Zhaoqi; Zhang, Jue; Fang, Jing

2013-01-01

The purpose of this study was to develop a novel intravascular loopless monopole antenna (ILMA) design specifically for imaging of small vessel walls. The ILMA consisted of an unshielded, low-friction guide wire and a tuning/matching box. The material of the guide wire was nitinol and it was coated with polyurethane. Because the guide wire was unshielded, it could be made thinner than the coaxial cable-based loopless intravascular antenna design. The material of the box was aluminum. In this study, the diameter of the guide wire was 0.5 mm and the length was 58.7 mm. The ILMA was used as a receiving antenna and body coil for transmission. To verify the feasibility of the ILMA, in vitro and in vivo experiments were performed on a 3.0-T magnetic resonance (MR) scanner. In vitro tests using the ILMA indicated that the proposed design could be used to image target vessel walls with a spatial resolution of 313 μm at the frequency coding direction and more than 100 mm of longitudinal coverage. In vivo tests demonstrated that the images showed the vessel walls clearly by using the ILMA and also indicated that the ILMA could be used for small vessels. The proposed antenna may therefore be utilized to promote MR-based diagnoses and therapeutic solutions for cardiovascular atherosclerotic diseases. Copyright © 2013 Elsevier Inc. All rights reserved.

Transthoracic ultrasound guided balloon dilation of cor triatriatum dexter in 2 Rottweiler puppies.

PubMed

Birettoni, F; Caivano, D; Bufalari, A; Giorgi, M E; Miglio, A; Paradies, P; Porciello, F

2016-12-01

Balloon dilation was performed in two Rottweiler puppies with cor triatriatum dexter and clinical signs of ascites using transthoracic echocardiographic guidance. The dogs were positioned on a standard echocardiography table in right lateral recumbency, and guide wires and balloon catheters were imaged by echocardiographic views optimized to allow visualization of the defect. The procedures were performed successfully without complications and clinical signs were resolved completely in both cases. Guide wires and balloon catheters appeared hyperechoic on transthoracic echocardiography image and could be clearly monitored and guided in real-time. These two cases demonstrate that it is possible to perform balloon catheter dilation of cor triatriatum dexter under transthoracic guidance alone. Copyright © 2016 Elsevier B.V. All rights reserved.

Accidental entrapment of an endo-bronchial blocker tip by a surgical stapler during selective ventilation for lung lobectomy in a dog.

PubMed

Levionnois, Olivier L; Bergadano, Alessandra; Schatzmann, Urs

2006-01-01

To describe the use of an endobronchial blocker (EBB) and to perform selective ventilation during pulmonary lobe resection via thoracotomy in a dog and report its accidental stapling in the resection site. Clinical case report. One female dog with a suspected abscess or neoplasia of the right caudal pulmonary lobe. One-lung ventilation was performed using a wire-guided EBB to seal the contaminated parenchyma and facilitate surgical access. The affected lung parenchyma was resected and the resection site was closed with staples. Lobar resection was performed successfully, but the loop of the EBB guide wire was inadvertently entrapped in the staple line of the lobectomy. Staples were removed to release the wire loop, and the resulting air leak caused loss of ventilation control until the parenchyma was re-sealed. We recommend removing the wire guide associate with the EBB after successful lung separation to avoid accidents that could have life-threatening consequences if not recognized. One-lung ventilation is useful to isolate healthy parenchyma from diseased parenchyma during lobectomy. Anesthesiologists and surgeons need to be aware of the potential complications associated with use of EBB.

Separate Vertical Wiring for the Fixation of Comminuted Fractures of the Inferior Pole of the Patella

PubMed Central

Song, Hyung Keun; Yoo, Je Hyun; Byun, Young Soo

2014-01-01

Purpose Among patients over 50 years of age, separate vertical wiring alone may be insufficient for fixation of fractures of the inferior pole of the patella. Therefore, mechanical and clinical studies were performed in patients over the age of 50 to test the strength of augmentation of separate vertical wiring with cerclage wire (i.e., combined technique). Materials and Methods Multiple osteotomies were performed to create four-part fractures in the inferior poles of eight pairs of cadaveric patellae. One patella from each pair was fixed with the separate wiring technique, while the other patella was fixed with a combined technique. The ultimate load to failure and stiffness of the fixation were subsequently measured. In a clinical study of 21 patients (average age of 64 years), comminuted fractures of the inferior pole of the patellae were treated using the combined technique. Operative parameters were recorded from which post-operative outcomes were evaluated. Results For cadaveric patellae, whose mean age was 69 years, the mean ultimate loads to failure for the separate vertical wiring technique and the combined technique were 216.4±72.4 N and 324.9±50.6 N, respectively (p=0.012). The mean stiffness for the separate vertical wiring technique and the combined technique was 241.1±68.5 N/mm and 340.8±45.3 N/mm, respectively (p=0.012). In the clinical study, the mean clinical score at final follow-up was 28.1 points. Conclusion Augmentation of separate vertical wiring with cerclage wire provides enough strength for protected early exercise of the knee joint and uneventful healing. PMID:24719149

A novel technique of concurrent esophagoscopy and transgastrostomy gastroscopy to dilate a completely obstructed distal esophageal stricture in a child following fundoplication.

PubMed

Isaiah, J H; Jones, A B; Lalor, E; Evans, M; Dhunno, I; Huynh, H Q

2005-08-01

We report a successful dilation of a completely obstructed distal esophageal stricture in a 4-year-old boy with combined immune deficiency syndrome, at 2 and half years after fundoplication and gastrostomy tube insertion. Barium studies and esophagoscopy had revealed complete obstruction of the lower esophagus. Transgastrostomy gastroscopy demonstrated a pinhole lumen through the fundoplication wrap; a guide wire was passed into the esophagus; and the stricture was dilated with Savary dilators. We presumed that the stricture was secondary to chronic esophagitis. The stricture was identified and successfully dilated using a novel technique of concurrent esophagoscopy and transgastrostomy gastroscopy.

Techniques to measure tension in wires or straw tubes

NASA Astrophysics Data System (ADS)

Oh, S. H.; Lin, S.; Wang, C.

2018-01-01

We discuss two different ways of measuring the tension in light wires and straws. The first technique uses an operational amplifier to subtract out the oscillating driving voltage mixed in the output voltage, which also has the signal. The isolated signal is amplified and displayed in an oscilloscope. In the second technique, an analog switch routes the oscillating voltage to a wire for a fraction of seconds, and then switches off the voltage. As the voltage is turned off, the induced signal from the wire is routed to an amplifier-rectifier circuit for a fraction of a second to measure the signal size as a function of the driving frequency. The first technique fits well to measure a single wire, while the second one fits well to measure many wires, 16 in our case, at a time.

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs).

PubMed

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-04-30

BACKGROUND Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. CASE REPORT We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. CONCLUSIONS The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations.

Endotherapy for severe and complete pharyngo-esophageal post-radiation stenosis using wires, balloons and pharyngo-esophageal puncture (PEP) (with videos).

PubMed

Tang, Shou-jiang; Singh, Shailender; Truelson, John M

2010-01-01

Pharyngo-esophageal stenosis (PES) and upper esophageal stricture are common in patients who receive radiation therapy for laryngeal and hypopharyngeal cancers. In severe or complete stenosis, the patients generally have complete dysphagia with inability to swallow their saliva. Diagnostic and therapeutic esophagogastroduodenoscopy (EGD) plays an important role in investigating the dysphagia and in managing the underlying stenosis. We translate endoscopic retrograde cholangiopancreatography (ERCP) techniques and skills in approaching pancreaticobiliary obstruction in the management of severe and complete PES. We select and report three cases of severe or complete PES in which flexible endoscopic therapy was successfully provided by using fluoroscopy, ERCP wire guides, endoscopic balloons, and by performing pharyngo-esophageal puncture (PEP). We propose the term PEP in managing complete PES. We believe this approach can offer safety and efficiency with very high success rate.

Wire Crimp Connectors Verification using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

[Osteosynthesis by tension band wiring of displaced fractures of the olecranon].

PubMed

Doursounian, L; Prevot, O; Touzard, R C

1994-01-01

Fifty-two displaced olecranon fractures in adults were treated over a 5-year period. Minimum follow-up was 6 months. Forty-eight fractures were operated and 38 were treated by tension band wiring technique. This technique, applied for all types of fractures, gave good functional results in 33 cases (87%) and fair functional results in 5 cases. Complications include 1 pseudarthrosis, 2 loss of reduction, 2 transient tourniquet palsy and 13 skin problems due to wire protrusion. Tension band wiring is a simple safe and effective technique for displaced olecranon fractures but often requires K-wire removal.

Percutaneous Management of Accidentally Retained Foreign Bodies During Image-Guided Non-vascular Procedures: Novel Technique Using a Large-Bore Biopsy System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Garnon, Julien, E-mail: juleiengarnon@gmail.com; Ramamurthy, Nitin, E-mail: nitin-ramamurthy@hotmail.com

ObjectiveTo describe a novel percutaneous image-guided technique using a large-bore biopsy system to retrieve foreign bodies (FBs) accidentally retained during non-vascular interventional procedures.Materials and MethodsBetween May 2013 and October 2015, five patients underwent percutaneous retrieval of five iatrogenic FBs, including a biopsy needle tip in the femoral head following osteoblastoma biopsy and radiofrequency ablation (RFA); a co-axial needle shaft within a giant desmoid tumour following cryoablation; and three post-vertebroplasty cement tails within paraspinal muscles. All FBs were retrieved immediately following original procedures under local or general anaesthesia, using combined computed tomography (CT) and fluoroscopic guidance. The basic technique involved positioningmore » a 6G trocar sleeve around the FB long axis and co-axially advancing an 8G biopsy needle to retrieve the FB within the biopsy core. Retrospective chart review facilitated analysis of procedures, FBs, technical success, and complications.ResultsMean FB size was 23 mm (range 8–74 mm). Four FBs were located within 10 mm of non-vascular significant anatomic structures. The basic technique was successful in 3 cases; 2 cases required technical modifications including using a stiff guide-wire to facilitate retrieval in the case of the post-cryoablation FB; and using the central mandrin of the 6G trocar to push a cement tract back into an augmented vertebra when initial retrieval failed. Overall technical success (FB retrieval or removal to non-hazardous location) was 100 %, with no complications.ConclusionPercutaneous image-guided retrieval of iatrogenic FBs using a large-bore biopsy system is a feasible, safe, effective, and versatile technique, with potential advantages over existing methods.« less

Hot-wire anemometry in hypersonic helium flow

NASA Technical Reports Server (NTRS)

Wagner, R. D.; Weinstein, L. M.

1974-01-01

Hot-wire anemometry techniques are described that have been developed and used for hypersonic-helium-flow studies. The short run time available dictated certain innovations in applying conventional hot-wire techniques. Some examples are given to show the application of the techniques used. Modifications to conventional equipment are described, including probe modifications and probe heating controls.

The virtual isocentric aiming device: a new mechanical targeting concept.

PubMed

Mendel, Thomas; Hänni, Markus; Gueorguiev, Boyko; Wohlrab, David; Hofmann, Gunther Olaf

2011-12-01

Minimally invasive fracture fixation can be technically demanding, especially in body regions characterised by complex bone anatomy and the presence of a significant amount of soft tissue. Hence, this procedure is associated with a high risk of implant malposition. As a consequence, radiation exposure to the patient and the surgeon increases within surgery. The purpose of this study was to evaluate the practicability and accuracy of a newly designed virtual isocentric aiming device (VIAD) as compared to the more traditional approach of the freehand insertion of K-wires. Forty polyurethane foam blocks were prepared with a reference wire (W ( R )) and covered by sponge material to simulate soft tissue. For the sake of comparison, both an untrained and an experienced surgeon were selected for the study and were advised to insert a K-wire into the foam block so as to have the same axis as the W ( R ) using both of the aforementioned methods. The clinical parameters of both techniques were analysed. In addition, 3-D precision data computed using CT-scans of each sample were evaluated. Device adjustment prolonged the time required for the experienced surgeon to complete the VIAD procedure when compared to the freehand method. However, using the VIAD, the number of plane changes made to the image intensifier in addition to the number of drill trials was significantly reduced by each surgeon. Furthermore, mechanical K-wire navigation leads to a decrease in the radiation exposure time for the untrained surgeon. VIAD-guided K-wires revealed a significant lower angle of deviation in relation to W ( R ). Tip-to-tip and tip-to-axis distances displayed a trend indicating reduced displacement values as well. The VIAD allows for simple wire insertion with increased precision as well as a reduction in radiation exposure, plane changes of the image intensifier and the number of drill trials compared to the freehand method. The VIAD also satisfies the demand for a less invasive technique. Prospectively, the VIAD represents a useful and cost-effective alternative to the freehand method.

Neoinfundibulotomy for the management of symptomatic caliceal diverticula.

PubMed

Auge, Brian K; Munver, Ravi; Kourambas, John; Newman, Glenn E; Wu, Ning Z; Preminger, Glenn M

2002-04-01

Direct percutaneous access provides effective treatment for complex caliceal diverticula. Yet, access into the diverticulum alone is usually tenuous and passage of a guide wire across a stenotic infundibulum is often impossible. An alternative technique is described which creates a "neoinfundibulum" to assist in the management of symptomatic caliceal diverticula. During a 6-year period 22 patients with symptomatic caliceal diverticula were treated via a percutaneous approach, of whom 21 had calculi within the diverticula. After accessing the diverticulum directly, it was impossible to pass a guide wire through the stenotic infundibulum in 18 (82%) patients, prompting advancement of the access needle through the diverticular wall into the renal pelvis. Once secure access was established, balloon dilation was performed to 30Fr to create the "neoinfundibulum." Percutaneous ultrasonic lithotripsy was performed in the usual fashion. A 22Fr Councill catheter was placed to keep the infundibular tract open for 5 to 7 days to allow complete epithelialization and drainage. Stone-free, symptom-free and complication rates were assessed. Pain, recurrent urinary tract infections and hematuria were the presenting complaints in the subgroup of patients undergoing "neoinfundibulotomy." Average stone burden was 11.7 x 12 mm. and average hospital stay was 2.8 days. Of the patients 94% were symptom-free at 6-week followup, and 80% were stone-free on followup excretory urography. The remaining patients had residual stone fragments less than 3 mm. in diameter. Complications related to access were identified in 2 patients who sustained a pneumothorax after a supra-11th rib access, which was successfully managed with tube thoracostomy. Percutaneous management of complex caliceal diverticula provides a safe and effective option for symptomatic patients. When the stenotic infundibulum cannot be traversed with a guide wire, creation of a new infundibulum offers a secure alternative for accessing the collecting system, while providing equally effective results.

Magnetic resonance imaging-radioguided occult lesion localization (ROLL) in breast cancer using Tc-99m macro-aggregated albumin and distilled water control.

PubMed

Philadelpho Arantes Pereira, Fernanda; Martins, Gabriela; Gregorio Calas, Maria Julia; Fonseca Torres de Oliveira, Maria Veronica; Gasparetto, Emerson Leandro; Barbosa da Fonseca, Lea Mirian

2013-09-18

Magnetic resonance imaging (MRI) guided wire localization presents several challenges apart from the technical difficulties. An alternative to this conventional localization method using a wire is the radio-guided occult lesion localization (ROLL), more related to safe surgical margins and reductions in excision volume. The purpose of this study was to establish a safe and reliable magnetic resonance imaging-radioguided occult lesion localization (MRI-ROLL) technique and to report our initial experience with the localization of nonpalpable breast lesions only observed on MRI. Sixteen women (mean age 53.2 years) with 17 occult breast lesions underwent radio-guided localization in a 1.5-T MR system using a grid-localizing system. All patients had a diagnostic MRI performed prior to the procedure. An intralesional injection of Technetium-99m macro-aggregated albumin followed by distilled water was performed. After the procedure, scintigraphy was obtained. Surgical resection was performed with the help of a gamma detector probe. The lesion histopathology and imaging concordance; the procedure's positive predictive value (PPV), duration time, complications, and accuracy; and the rate of exactly excised lesions evaluated with MRI six months after the surgery were assessed. One lesion in one patient had to be excluded because the radioactive substance came back after the injection, requiring a wire placement. Of the remaining cases, there were four malignant lesions, nine benign lesions, and three high-risk lesions. Surgical histopathology and imaging findings were considered concordant in all benign and high-risk cases. The PPV of MRI-ROLL was greater if the indication for the initial MR examination was active breast cancer. The median procedure duration time was 26 minutes, and all included procedures were defined as accurate. The exact and complete lesion removal was confirmed in all (100%) patients who underwent six-month postoperative MRI (50%). MRI-ROLL offers a precise, technically feasible, safe, and rapid means for performing preoperative MRI localizations in the breast.

High accuracy electronic material level sensor

DOEpatents

McEwan, T.E.

1997-03-11

The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: (1) a high accuracy time base that is referenced to a quartz crystal, (2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, (3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or ``ghost`` reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%. 4 figs.

High accuracy electronic material level sensor

DOEpatents

McEwan, Thomas E.

1997-01-01

The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: 1) a high accuracy time base that is referenced to a quartz crystal, 2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, 3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or "ghost" reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%.

Health monitoring of prestressing tendons in post-tensioned concrete structures

NASA Astrophysics Data System (ADS)

Salamone, Salvatore; Bartoli, Ivan; Nucera, Claudio; Phillips, Robert; Lanza di Scalea, Francesco

2011-04-01

Currently 90% of bridges built in California are post-tensioned box-girder. In such structures the steel tendons are the main load-carrying components. The loss of prestress, as well as the presence of defects or the tendon breakage, can be catastrophic for the entire structure. Unfortunately, today there is no well-established method for the monitoring of prestressing (PS) tendons that can provide simultaneous information related to the presence of defects and the level of prestress in a continuous, real time manner. If such a monitoring system were available, considerable savings would be achieved in bridge maintenance since repairs would be implemented in a timely manner without traffic disruptions. This paper presents a health monitoring system for PS tendons in post-tensioned structures of interest to Caltrans. Such a system uses ultrasonic guided waves and embedded sensors to provide simultaneously and in real time, (a) measurements of the level of applied prestress, and (b) defect detection at early grow stages. The proposed PS measurement technique exploits the sensitivity of ultrasonic waves to the inter-wire contact developing in a multi-wire strand as a function of prestress level. In particular the nonlinear ultrasonic behavior of the tendon under changing levels of prestress is monitored by tracking higher-order harmonics at (nω) arising under a fundamental guided-wave excitation at (ω). Moreover this paper also present real-time damage detection and location in post-tensioned bridge joints using Acoustic Emission techniques. Experimental tests on large-scale single-tendon PT joint specimens, subjected to multiple load cycles, will be presented to validate the monitoring of PS loads (through nonlinear ultrasonic probing) and the monitoring of damage progression and location (through acoustic emission techniques). Issues and potential for the use of such techniques to monitor post-tensioned bridges in the field will be discussed.

Fluoroscopic guide wire manipulation of malfunctioning peritoneal dialysis catheters initially placed by interventional radiologists.

PubMed

Kwon, Young Ho; Kwon, Se Hwan; Oh, Joo Hyeong; Jeong, Kyung Hwan; Lee, Tae Won

2014-06-01

To assess the efficacy of fluoroscopic guide wire manipulation in patients with malfunctioning peritoneal dialysis (PD) catheters that were initially placed by interventional radiologists under fluoroscopic guidance. From January 2002 to April 2012, 52 patients (mean age, 52.8 y ± 2.10s; range, 12-79 y) with malfunctioning PD catheters in whom fluoroscopic guide wire manipulation was performed were retrospectively reviewed. Technical success, clinical success, and complications were evaluated. Technical success was defined as fluoroscopically verified, successful catheter repositioning and adequate dialysate drainage after the procedure. Clinical success was defined as maintenance of PD catheter function for at least 30 days after the manipulation. During the study period, 72 manipulations (68 initial manipulations and 4 remanipulations) for malfunctioning PD catheters were done. The technical success rate was 74% (50 of 68) for initial manipulations and 75% (3 of 4) for remanipulations. The overall clinical success rate was 47% (32 of 68) for initial manipulations and 0% (0 of 4) for remanipulations. The primary causes of catheter malfunction were extraluminal obstruction by omental wrapping or adhesions in 43 of 68 cases (63.2%) and catheter malposition in 25 of 68 (36.8%) cases. There were no procedure-related major complications. Fluoroscopic guide wire manipulation in patients with malfunctioning PD catheters initially placed by interventional radiologists is a simple procedure, an effective way of prolonging PD catheter life, and a recommended procedure before invasive surgical procedures. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

Minimally invasive guidewireless, navigated pedicle screw placement: a technical report and case series.

PubMed

Smith, Brandon W; Joseph, Jacob R; Kirsch, Michael; Strasser, Mary Oakley; Smith, Jacob; Park, Paul

2017-08-01

OBJECTIVE Percutaneous pedicle screw insertion (PPSI) is a mainstay of minimally invasive spinal surgery. Traditionally, PPSI is a fluoroscopy-guided, multistep process involving traversing the pedicle with a Jamshidi needle, placement of a Kirschner wire (K-wire), placement of a soft-tissue dilator, pedicle tract tapping, and screw insertion over the K-wire. This study evaluates the accuracy and safety of PPSI with a simplified 2-step process using a navigated awl-tap followed by navigated screw insertion without use of a K-wire or fluoroscopy. METHODS Patients undergoing PPSI utilizing the K-wire-less technique were identified. Data were extracted from the electronic medical record. Complications associated with screw placement were recorded. Postoperative radiographs as well as CT were evaluated for accuracy of pedicle screw placement. RESULTS Thirty-six patients (18 male and 18 female) were included. The patients' mean age was 60.4 years (range 23.8-78.4 years), and their mean body mass index was 28.5 kg/m 2 (range 20.8-40.1 kg/m 2 ). A total of 238 pedicle screws were placed. A mean of 6.6 pedicle screws (range 4-14) were placed over a mean of 2.61 levels (range 1-7). No pedicle breaches were identified on review of postoperative radiographs. In a subgroup analysis of the 25 cases (69%) in which CT scans were performed, 173 screws were assessed; 170 (98.3%) were found to be completely within the pedicle, and 3 (1.7%) demonstrated medial breaches of less than 2 mm (Grade B). There were no complications related to PPSI in this cohort. CONCLUSIONS This streamlined 2-step K-wire-less, navigated PPSI appears safe and accurate and avoids the need for radiation exposure to surgeon and staff.

Towards a Reduced-Wire Interface for CMUT-Based Intravascular Ultrasound Imaging Systems

PubMed Central

Lim, Jaemyung; Tekes, Coskun; Degertekin, F. Levent; Ghovanloo, Maysam

2016-01-01

Having intravascular ultrasound (IVUS) imaging capability on guide wires used in cardiovascular interventions may eliminate the need for separate IVUS catheters and expand the use of IVUS in a larger portion of the vasculature. High frequency capacitive micro machined ultrasonic transducer (CMUT) arrays should be integrated with interface electronics and placed on the guide wire for this purpose. Besides small size, this system-on-a-chip (SoC) front-end should connect to the back-end imaging system with a minimum number of wires to preserve the critical mechanical properties of the guide wire. We present a 40 MHz CMUT array interface SoC, which will eventually use only two wires for power delivery and transmits image data using a combination of analog-to-time conversion (ATC) and an impulse radio ultra-wideband (IR-UWB) wireless link. The proof-of-concept prototype ASIC consumes only 52.8 mW and occupies 4.07 mm2 in a 0.35-μm standard CMOS process. A rectifier and regulator power the rest of the SoC at 3.3 V from a 10 MHz power carrier that is supplied through a 2.4 m micro-coax cable with an overall efficiency of 49.1%. Echo signals from an 8-element CMUT array are amplified by a transimpedance amplifier (TIA) array and down-converted to baseband by quadrature sampling using a 40 MHz clock, derived from the power carrier. The ATC generates pulse-width-modulated (PWM) samples at 2 × 10 MS/s with 6 bit resolution, while the entire system achieved 5.1 ENOB. Preliminary images from the prototype system are presented, and alternative data transmission and possible future directions towards practical implementation are discussed. PMID:27662686

Towards a Reduced-Wire Interface for CMUT-Based Intravascular Ultrasound Imaging Systems.

PubMed

Lim, Jaemyung; Tekes, Coskun; Degertekin, F Levent; Ghovanloo, Maysam

2017-04-01

Having intravascular ultrasound (IVUS) imaging capability on guide wires used in cardiovascular interventions may eliminate the need for separate IVUS catheters and expand the use of IVUS in a larger portion of the vasculature. High frequency capacitive micro machined ultrasonic transducer (CMUT) arrays should be integrated with interface electronics and placed on the guide wire for this purpose. Besides small size, this system-on-a-chip (SoC) front-end should connect to the back-end imaging system with a minimum number of wires to preserve the critical mechanical properties of the guide wire. We present a 40 MHz CMUT array interface SoC, which will eventually use only two wires for power delivery and transmits image data using a combination of analog-to-time conversion (ATC) and an impulse radio ultra-wideband (IR-UWB) wireless link. The proof-of-concept prototype ASIC consumes only 52.8 mW and occupies 4.07 [Formula: see text] in a 0.35- [Formula: see text] standard CMOS process. A rectifier and regulator power the rest of the SoC at 3.3 V from a 10 MHz power carrier that is supplied through a 2.4 m micro-coax cable with an overall efficiency of 49.1%. Echo signals from an 8-element CMUT array are amplified by a transimpedance amplifier (TIA) array and down-converted to baseband by quadrature sampling using a 40 MHz clock, derived from the power carrier. The ATC generates pulse-width-modulated (PWM) samples at 2 × 10 MS/s with 6 bit resolution, while the entire system achieved 5.1 ENOB. Preliminary images from the prototype system are presented, and alternative data transmission and possible future directions towards practical implementation are discussed.

The chopstick-noodle twist: an easy technique of percutaneous patellar fixation in minimally displaced patellar fractures.

PubMed

Muzaffar, Nasir; Ahmad, Nawaz; Ahmad, Aejaz; Ahmad, Nissar

2012-01-01

We report six cases of minimally displaced two-part patellar fractures with skin injury over the patella that were treated with percutaneous K wire fixation and compression applied using stainless steel (SS) wire. This technique makes it possible to perform early operative treatment in cases where unhealthy skin is not amenable to conventional tension band wiring. The technique employs two K wires inserted through the two fracture fragments under local or regional anaesthesia. They are then compressed using simple SS wire knots at the two ends - making it look like noodles at the end of two chopsticks. The fixation is subsequently augmented with a cylindrical plaster-of-Paris cast. The technique is simple, cheap and does not cause soft tissue injury.

Bose Condensation and Lasing in Optical Microstructures - Part 1

NASA Astrophysics Data System (ADS)

Szymanska, M. H.

2002-04-01

In the first part of this thesis I study the intermediate regime between ordinary lasing and a BEC of exciton polaritons. I take into account the fermionic structure of polaritons, treating the excitons as two-level systems coupled to a single mode in a microcavity. I introduce decoherence and dissipation processes to this system. Employing many-body Green function techniques, similar to those used by Abrikosov and Gor'kov in their theory of gapless superconductivity, I provide a mathematical structure that unifies models of lasers with models of condensates. This allows me to study the stability of the polariton condensate with respect to decoherence processes and the crossover between the polariton condensate and the laser. I give detailed indications of a regime in which the condensate should be observed to guide experimental work and show how to distinguish the Bose condensate from a laser. The second part of this thesis is concerned with properties of excitons and modelling of excitonic lasing in quasi-one-dimensional quantum wires. I develop a very general numerical method of calculating the properties of wires with different shapes and materials. Using this method I study the properties of very wide range of T-shaped quantum wires.

Custom-Made Finger Guard to Prevent Wire-Stick Injury to the Operator's Finger while Performing Intermaxillary Fixation.

PubMed

Kumaresan, Ramesh; Ponnusami, Karthikeyan; Karthikeyan, Priyadarshini

2014-12-01

The treatment of maxillofacial fractures involves different methods from bandages and splinting to methods of open reduction and internal fixation and usually requires control of the dental occlusion with the help of intermaxillary fixation (IMF). Different wiring techniques have been used to aid in IMF including placement of custom-made arch bars, eyelet etc. However, these wiring techniques are with a constant danger of trauma to the surgeon's fingers by their sharp ends. Though there exist a variety of commercially available barrier products and customized techniques to prevent wire-stick injury, cost factor, touch sensitivity, and comfort aspect restrain their acquirement and exploit. This technical note describes the construction of a simple and economical finger guard made of soft thermoplastic material that provides an added protection to fingers from wire-stick type injuries, and its flexible nature permits a comfortable finger flexion movement and acceptable touch sensitivity. This is a simple, economical, reusable puncture, and cut-resistance figure guard by which we can avoid wire-stick type injury to the operator's fingers during wiring technique.

Side-Branch and Coaxial Intravascular Ultrasound Guided Wire Re-Entry after Failed Retrograde Approach of Chronic Total Occlusion Intervention.

PubMed

Chou, Ruey-Hsing; Lai, Chih-Hung; Lu, Tse-Min

2016-05-01

Intravascular ultrasound (IVUS) can provide valuable information during the intervention of difficult chronic total occlusion (CTO) lesion. Stumpless CTO lesions with an adjacent side branch are associated with a significantly lower success rate because the proper entry point is not always clearly identified and the guidewires easily slip into the side branch. Herein we presented a case of a stumpless middle left circumflex (LCX) artery CTO lesion with auto-collateral from obtuse marginal branch. Initially, we positioned the IVUS into the side-branch to find the entry point of LCX-CTO lesion. However, the punctured wire went into the false lumen. A retrograde approach was tried but later failed. Therefore, we used IVUS to find the entry point where the true lumen transited to the false lumen, and used a stiff guidewire to puncture the entry point. After we confirmed with IVUS that the whole guidewire was in the true lumen, we deployed 3 drug-eluting stents. The final angiogram showed TIMI 3 flow with preservation of all side branches. The patient was angina-free during the 6-month follow-up. By presenting this case, we have demonstrated the application of both side-branch and coaxial IVUS-guided recanalization technique in the stumpless CTO lesion.

Method and apparatus for diamond wire cutting of metal structures

DOEpatents

Parsells, Robert; Gettelfinger, Geoff; Perry, Erik; Rule, Keith

2005-04-19

A method and apparatus for diamond wire cutting of metal structures, such as nuclear reactor vessels, is provided. A diamond wire saw having a plurality of diamond beads with beveled or chamfered edges is provided for sawing into the walls of the metal structure. The diamond wire is guided by a plurality of support structures allowing for a multitude of different cuts. The diamond wire is cleaned and cooled by CO.sub.2 during the cutting process to prevent breakage of the wire and provide efficient cutting. Concrete can be provided within the metal structure to enhance cutting efficiency and reduce airborne contaminants. The invention can be remotely controlled to reduce exposure of workers to radioactivity and other hazards.

Medial malleolar fractures: a biomechanical study of fixation techniques.

PubMed

Fowler, T Ty; Pugh, Kevin J; Litsky, Alan S; Taylor, Benjamin C; French, Bruce G

2011-08-08

Fracture fixation of the medial malleolus in rotationally unstable ankle fractures typically results in healing with current fixation methods. However, when failure occurs, pullout of the screws from tension, compression, and rotational forces is predictable. We sought to biomechanically test a relatively new technique of bicortical screw fixation for medial malleoli fractures. Also, the AO group recommends tension-band fixation of small avulsion type fractures of the medial malleolus that are unacceptable for screw fixation. A well-documented complication of this technique is prominent symptomatic implants and secondary surgery for implant removal. Replacing stainless steel 18-gauge wire with FiberWire suture could theoretically decrease symptomatic implants. Therefore, a second goal was to biomechanically compare these 2 tension-band constructs. Using a tibial Sawbones model, 2 bicortical screws were compared with 2 unicortical cancellous screws on a servohydraulic test frame in offset axial, transverse, and tension loading. Second, tension-band fixation using stainless steel wire was compared with FiberWire under tensile loads. Bicortical screw fixation was statistically the stiffest construct under tension loading conditions compared to unicortical screw fixation and tension-band techniques with FiberWire or stainless steel wire. In fact, unicortical screw fixation had only 10% of the stiffness as demonstrated in the bicortical technique. In a direct comparison, tension-band fixation using stainless steel wire was statistically stiffer than the FiberWire construct. Copyright 2011, SLACK Incorporated.

Advanced wiring technique and hardware application: Airplane and space vehicle

NASA Technical Reports Server (NTRS)

Ernst, H. L.; Eichman, C. D.

1972-01-01

An advanced wiring system is described which achieves the safety/reliability required for present and future airplane and space vehicle applications. Also, present wiring installation techniques and hardware are analyzed to establish existing problem areas. An advanced wiring system employing matrix interconnecting unit, plug to plug trunk bundles (FCC or ribbon cable) is outlined, and an installation study presented. A planned program to develop, lab test and flight test key features of these techniques and hardware as a part of the SST technology follow-on activities is discussed.

Aircraft Crash Survival Design Guide. Volume 4. Aircraft Seats, Restraints, Litters, and Cockpit/Cabin Delethalization

DTIC Science & Technology

1989-12-01

ILLUSTRATIONS (CONTD) 44 Tubular strut wire - bending energy absorber ...... ........... 91 45 Inversion tube concepL with typical force-deformation...expected from a rod-bending sled decelerator and a wire - bending seat load limiter (Refer- ences 35 and 36). Therefore, correcting the calculated...attaching the seat bucket to the rollers, compressive as well as tensile loads can be sustained. Two variations of the wire - bending device have been

Aircraft Crash Survival Design Guide. Volume 4. Aircraft Seats, Restraints. Litters, and Padding

DTIC Science & Technology

1980-06-01

11i 34 Tubular strut wire - bending energy absorber with force-deflection curves ..... . . . . . . . . . . 113 35 Inversion tube concept with...decelera- tor and a wire - bending seat load limiter (References 31 and 32). Therefore, correcting the calculated distance yields 16.25/0.8 - 20.31 in. It...Naval Air Development Center, Warminster, Pennsylvania, October 1969. )- 109 I-. - - ’. Two variations of the wire - bending device have been developed and

Antipilferage Seal User’s Guide

DTIC Science & Technology

1997-10-01

seal is properly installed, ensure that there is no free play between the seal body and the wire. Verify and record the serial number. During post...and Record - Once the seal is properly installed, ensure that there is no free play between the seal body and the wire. During post-mortem...seal is properly installed, ensure that there is no free play between the seal body and the wire. Verify and record the serial number. During post

Building Trades. Carpentry, Electrical Wiring, Plumbing.

ERIC Educational Resources Information Center

Missouri Univ., Columbia. Instructional Materials Lab.

This curriculum guide contains 21 units of self-paced, self-contained instructional materials in the complete building trades curriculum. It is divided into vocational areas of carpentry, electrical wiring, and plumbing. The purpose of the curriculum is to provide minimum skills for disadvantaged and handicapped students entering mainstream…

Strength of surgical wire fixation. A laboratory study.

PubMed

Guadagni, J R; Drummond, D S

1986-08-01

Because of the frequent use of stainless steel wire in spinal surgery and to augment fracture fixation, several methods of securing wire fixation were tested in the laboratory to determine the relative strength of fixation. Any method of fixation stronger than the yield strength of the wire is sufficient. Square knots, knot twists, symmetric twists, and the AO loop-tuck techniques afforded acceptable resistance against tension loads, but the wire wrap and AO loop technique were unacceptable. The double symmetric twist, which is frequently used for tension banding, was barely acceptable. The symmetric twist technique was the most practical because it is strong enough, efficient in maintaining tension applied during fixation, and least likely to cause damage to the wire. To optimize the fixation strength of the symmetrical twist, at least two twists are required at a reasonably tight pitch.

0.025-inch vs 0.035-inch guide wires for wire-guided cannulation during endoscopic retrograde cholangiopancreatography: A randomized study

PubMed Central

Kitamura, Katsuya; Yamamiya, Akira; Ishii, Yu; Sato, Yoshiki; Iwata, Tomoyuki; Nomoto, Tomohiro; Ikegami, Akitoshi; Yoshida, Hitoshi

2015-01-01

AIM: To compare the clinical outcomes between 0.025-inch and 0.035-inch guide wires (GWs) when used in wire-guided cannulation (WGC). METHODS: A single center, randomized study was conducted between April 2011 and March 2013. This study was approved by the Medical Ethics Committee at our hospital. Informed, written consent was obtained from each patient prior to study enrollment. Three hundred and twenty-two patients with a naïve papilla of Vater who underwent endoscopic retrograde cholangiopancreatography (ERCP) for the purpose of selective bile duct cannulation with WGC were enrolled in this study. Fifty-three patients were excluded based on the exclusion criteria, and 269 patients were randomly allocated to two groups by a computer and analyzed: the 0.025-inch GW group (n = 109) and the 0.035-inch GW group (n = 160). The primary endpoint was the success rate of selective bile duct cannulation with WGC. Secondary endpoints were the success rates of the pancreatic GW technique and precutting, selective bile duct cannulation time, ERCP procedure time, the rate of pancreatic duct stent placement, the final success rate of selective bile duct cannulation, and the incidence of post-ERCP pancreatitis (PEP). RESULTS: The primary success rates of selective bile duct cannulation with WGC were 80.7% (88/109) and 86.3% (138/160) for the 0.025-inch and the 0.035-inch groups, respectively (P = 0.226). There were no statistically significant differences in the success rates of selective bile duct cannulation using the pancreatic duct GW technique (46.7% vs 52.4% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.884) or in the success rates of selective bile duct cannulation using precutting (66.7% vs 63.6% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.893). The final success rates for selective bile duct cannulation using these procedures were 92.7% (101/109) and 97.5% (156/160) for the 0.025-inch and 0.035-inch groups, respectively (P = 0.113). There were no significant differences in selective bile duct cannulation time (median ± interquartile range: 3.7 ± 13.9 min vs 4.0 ± 11.2 min for the 0.025-inch and 0.035-inch groups, respectively; P = 0.851), ERCP procedure time (median ± interquartile range: 32 ± 29 min vs 30 ± 25 min for the 0.025-inch and 0.035-inch groups, respectively; P = 0.184) or in the rate of pancreatic duct stent placement (14.7% vs 15.6% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.832). The incidence of PEP was 2.8% (3/109) and 2.5% (4/160) for the 0.025-inch and 0.035-inch groups, respectively (P = 0.793). CONCLUSION: The thickness of the GW for WGC does not appear to affect either the success rate of selective bile duct cannulation or the incidence of PEP. PMID:26290646

ACIST-FFR Study (Assessment of Catheter-Based Interrogation and Standard Techniques for Fractional Flow Reserve Measurement)

PubMed Central

Chambers, Jeffrey W.; Seto, Arnold H.; Sarembock, Ian J.; Raveendran, Ganesh; Sakarovitch, Charlotte; Yang, Lingyao; Desai, Manisha; Jeremias, Allen; Price, Matthew J.

2017-01-01

Background— Measurement of fractional flow reserve (FFR) to guide coronary revascularization lags despite robust supportive data, partly because of the handling characteristics of traditional coronary pressure wires. An optical pressure-monitoring microcatheter, which can be advanced over a traditional coronary guidewire, facilitates FFR assessment but may underestimate pressure wire–derived FFR. Methods and Results— In this prospective, multicenter trial, 169 patients underwent FFR assessment with a pressure wire alone and with a pressure microcatheter over the pressure wire. An independent core laboratory performed quantitative coronary angiography and evaluated all pressure tracings. The primary end point was the bias or difference between the microcatheter FFR and the pressure wire FFR, as assessed by Bland–Altman analysis. The mean difference between the microcatheter and the pressure wire–derived FFR values was −0.022 (95% confidence interval, −0.029 to −0.015). On multivariable analysis, reference vessel diameter (P=0.027) and lesion length (P=0.044) were independent predictors of bias between the 2 FFR measurements. When the microcatheter FFR was added to this model, it was the only independent predictor of bias (P<0.001). The mean FFR value from the microcatheter was significantly lower than from the pressure wire (0.81 versus 0.83; P<0.001). In 3% of cases (95% confidence interval, 1.3%–6.7%), there was clinically meaningful diagnostic discordance, with the FFR from the pressure wire >0.80 and that from the microcatheter <0.75. These findings were similar when including all 210 patients with site-reported paired FFR data. Conclusions— An optical, pressure-monitoring microcatheter measures lower FFR compared with a pressure wire, but the diagnostic impact appears to be minimal in most cases. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifier: NCT02577484. PMID:29246917

The feasibility and safety of applying the Magnetic Navigation System to manage chronically occluded vessels: a single centre experience.

PubMed

Ramcharitar, Steve; van der Giessen, Willem J; van der Ent, Martin; de Feyter, Pim; Serruys, Patrick W; van Geuns, Robert-Jan

2011-01-01

Applying the Magnetic Navigation System (MNS) to manage chronic total occlusions (CTOs). The MNS precisely directs a magnetised guidewire in vivo through two permanent external magnets. The first 43 consecutive MNS treated CTOs were retrospectively evaluated. Computed tomography coronary angiography (CTCA) co-integration with the MNS provided a virtual road map through the occlusion. Unsuccessful MNS cases were managed with bailout conventional guidewire techniques. Experienced CTO and MNS operators had unrestricted access to CTO devices and equipments. The MNS crossing success increased from 40% to 56% over 52 months and averaged 44.2% (19/43 patients). In 58.3% (14/24) of failed MNS cases the conventional wire approach was successful, giving an overall procedural success rate of 76.6%. Of those conventionally treated, two patients required pericardiocentesis. On average, 1.8 ± 0.9 stents (lengths 44.7 ± 21.4 mm and diameter 2.8 ± 0.4 mm) were implanted. Procedural times were lengthy (125.0 ± 35.3 min) requiring high fluoroscopy dosage (11980.2 ± 6457.9 Gy/cm2) and contrast media usage (388.8 ± 170.2 ml). Operators persevered less with magnetic wires (20.9 ± 12.4 min vs. 27.7 ± 24.4 min), and preferentially used the least stiff wire as first choice (53.5%). CTCA co-integration did not influence procedural outcome. As with conventional wires, higher magnetic wire successes occurred in low calcified lesions, those with a central stump and without bridging collaterals. In unselected CTOs, the magnetic wires are safe and feasible. Current modest success rates with a high procedural bailout rate implicate the need for improved magnetic guidewire technology comparable to available sophisticated conventional CTO wires. Randomised studies are needed to clarify the value of magnetic guided recanalisation.

Augmented reality fluoroscopy simulation of the guide-wire insertion in DHS surgery: A proof of concept study.

PubMed

van Duren, B H; Sugand, K; Wescott, R; Carrington, R; Hart, A

2018-05-01

Hip fractures contribute to a significant clinical burden globally with over 1.6 million cases per annum and up to 30% mortality rate within the first year. Insertion of a dynamic hip screw (DHS) is a frequently performed procedure to treat extracapsular neck of femur fractures. Poorly performed DHS fixation of extracapsular neck of femur fractures can result in poor mobilisation, chronic pain, and increased cut-out rate requiring revision surgery. A realistic, affordable, and portable fluoroscopic simulation system can improve performance metrics in trainees, including the tip-apex distance (the only clinically validated outcome), and improve outcomes. We developed a digital fluoroscopic imaging simulator using orthogonal cameras to track coloured markers attached to the guide-wire which created a virtual overlay on fluoroscopic images of the hip. To test the accuracy with which the augmented reality system could track a guide-wire, a standard workshop femur was used to calibrate the system with a positional marker fixed to indicate the apex; this allowed for comparison between guide-wire tip-apex distance (TAD) calculated by the system to be compared to that physically measured. Tests were undertaken to determine: (1) how well the apex could be targeted; (2) the accuracy of the calculated TAD. (3) The number of iterations through the algorithm giving the optimal accuracy-time relationship. The calculated TAD was found to have an average root mean square error of 4.2 mm. The accuracy of the algorithm was shown to increase with the number of iterations up to 20 beyond which the error asymptotically converged to an error of 2 mm. This work demonstrates a novel augmented reality simulation of guide-wire insertion in DHS surgery. To our knowledge this has not been previously achieved. In contrast to virtual reality, augmented reality is able to simulate fluoroscopy while allowing the trainee to interact with real instrumentation and performing the procedure on workshop bone models. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Trade Electricity. Signal Wiring--Level 1. Standardized Curriculum.

ERIC Educational Resources Information Center

New York City Board of Education, Brooklyn, NY. Office of Occupational and Career Education.

This curriculum guide consists of nine modules on signal wiring, one of the three divisions of the standardized trade electricity curriculum in high schools in New York City. The modules cover the following subjects: bells, double contact pushbuttons, annunciator circuits, open circuit burglar alarms, closed circuit burglar alarms, fire alarms,…

Wire Crimp Termination Verification Using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Perey, Daniel F.; Cramer, K. Elliott; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp termination and wire is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. Various crimp junction pathologies such as undercrimping, missing wire strands, incomplete wire insertion, partial insulation removal, and incorrect wire gauge are ultrasonically tested, and their results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently (as evidenced with destructive testing) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. Finally, an approach for application to multipin indenter type crimps will be discussed.

Contemporary treatment of patients with chronic total occlusion: critical appraisal of different state-of-the-art techniques and devices.

PubMed

García-García, Héctor M; Kukreja, Neville; Daemen, Joost; Tanimoto, Shuzou; van Mieghem, Carlos; Gonzalo, Nieves; van Weenen, Sander; van der Ent, Martin; Sianos, Georgios; de Feyter, Pim; Serruys, Patrick W

2007-08-01

To describe the contemporary approach of chronic total occlusion (CTO) treatment of patients at the Thoraxcenter, Rotterdam, The Netherlands. Additionally, to make a critical appraisal of the performance of state-of-the-art CTO dedicated guidewires and devices in a prospective registry of patients. During 20 months, a total of 160 consecutive patients (165 CTOs) were enrolled. The mean age was 61.5+/-11.1 years and 83.6% were male. In 91.5% of the patients this was the first attempt to open the CTO and 93.8% were de novo. The overall success rate was 60.6%. A median of 1 guiding catheter was used per case (Range: 1 to 9) and a median of 4 guidewires (Range: 1 to 11; 13 different types). 74.5% patients required more than one guidewire/device for the treatment of the CTO. The guidewires that most frequently crossed the CTO were the following: PT Graphix intermediate 33.0%, Miracle 3 g 27.4% and Crosswire NT 25.5%. The only device tested as a first option for the treatment of the CTOs was the CROSSER. Overall, the CROSSER system was used in 23 (13.9%) patients with a success rate of 60.9%. The Point 9(R) X-80 Laser catheter was used in 10 (6.1%) patients with a success rate of 60%. Another 3 patients were treated with the Point 7(R) laser catheter. Both were used either to facilitate the crossing of the balloon, or to treat primarily in-stent restenosis occlusions. The SafeCross(R) System was used in 15 (9.1%) patients and the success rate in these patients was 46.7%. The most common strategy used in this registry was the use of an over-the-wire balloon in 81.5% of the cases. The parallel wire technique was used in 27.3% of the cases and in 12.7% was converted into a "see-saw" technique. When a large false lumen was created, re-entry into the true lumen was attempted in 21.2% of the cases, by means of IVUS guided approach and/or the use of stiffer guidewires, such as a Confianza guidewire. Retrograde recanalisation was attempted in 10 cases (6.1%), in three cases a graft was used; the remaining cases were treated either via collaterals or the septal branches. The treatment of CTOs requires the use of a high number of guiding catheters and guidewires, as well as the use of sophisticated devices. The procedure must be carefully planned in advance as far as possible, as well as considering a prompt change in approach during the performance of the procedure to prevent complications derived from long procedures by using specific techniques such as parallel wire, see-saw, anchoring balloon, etc.

Coil tubing fishing operations utilize a first time technique to strip over and recover 9500 feet of stuck slickline wire

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forgenie, V.H.; Heiberger, E.M.; Kelso, L.K.

1995-12-31

Coil tubing was utilized to perform a modified strip over operation and recover 9500 ft. of stuck slickline (0.108 in.) wire. The technique, thought to be an industry first, eliminated the risky option of recovering the wire piecemeal via conventional wireline fishing operations. This paper documents the background that lead to the development of the technique. An operational summary details its implementation and illustrations are included of the special tools and techniques employed.

Magnetic Resonance Imaging of the Codman Microsensor Transducer Used for Intraspinal Pressure Monitoring: Findings From the Injured Spinal Cord Pressure Evaluation Study.

PubMed

Phang, Isaac; Mada, Marius; Kolias, Angelos G; Newcombe, Virginia F J; Trivedi, Rikin A; Carpenter, Adrian; Hawkes, Rob C; Papadopoulos, Marios C

2016-05-01

Laboratory and human study. To test the Codman Microsensor Transducer (CMT) in a cervical gel phantom. To test the CMT inserted to monitor intraspinal pressure in a patient with spinal cord injury. We recently introduced the technique of intraspinal pressure monitoring using the CMT to guide management of traumatic spinal cord injury [Werndle et al. Crit Care Med 2014;42:646]. This is analogous to intracranial pressure monitoring to guide management of patients with traumatic brain injury. It is unclear whether magnetic resonance imaging (MRI) of patients with spinal cord injury is safe with the intraspinal pressure CMT in situ. We measured the heating produced by the CMT placed in a gel phantom in various configurations. A 3-T MRI system was used with the body transmit coil and the spine array receive coil. A CMT was then inserted subdurally at the injury site in a patient who had traumatic spinal cord injury and MRI was performed at 1.5 T. In the gel phantom, heating of up to 5°C occurred with the transducer wire placed straight through the magnet bore. The heating was abolished when the CMT wire was coiled and passed away from the bore. We then tested the CMT in a patient with an American Spinal Injuries Association grade C cervical cord injury. The CMT wire was placed in the configuration that abolished heating in the gel phantom. Good-quality T1 and T2 images of the cord were obtained without neurological deterioration. The transducer remained functional after the MRI. Our data suggest that the CMT is MR conditional when used in the spinal configuration in humans. Data from a large patient group are required to confirm these findings. N/A.

Balloon dilatation of benign and malignant esophageal strictures. Blind retrograde balloon dilatation.

PubMed

Graham, D Y; Smith, J L

1985-06-01

Balloon esophageal dilatation offers many theoretical advantages (safety, speed, and patient comfort) over dilatation with mercury-filled bougies or with the Eder-Puestow system. The authors used balloon dilators in 22 patients with dysphagia secondary to benign or malignant strictures. Dilatation was performed with fluoroscopic guidance, blindly, or by a combination of these techniques. For "blind" stricture dilatation, an Eder-Puestow spring-tipped guide wire is placed into the stomach using a fiberoptic endoscope. The distance from the incisor teeth to the stricture is measured, and the balloon shaft is marked to indicate when the middle of the balloon is within the stricture. Dilatation is then performed using the antegrade or, the preferred, retrograde technique. Finally, the dilated stricture is calibrated by pulling an inflated balloon through the previously strictured area without difficulty. An attempt was made to achieve an esophageal diameter of 15 mm at the initial dilatation episode, and patient discomfort was used as a guide as to the final diameter. The balloon dilatation technique was highly successful, and a stricture diameter of 15 mm (45-47 French) was achieved at the initial dilatation in most instances. Malignant strictures were easily dilated. Balloon dilatation is convenient, effective, quick, and potentially safer than the previous Eder-Puestow or mercury-filled bougie techniques.

Online C-arm calibration using a marked guide wire for 3D reconstruction of pulmonary arteries

NASA Astrophysics Data System (ADS)

Vachon, Étienne; Miró, Joaquim; Duong, Luc

2017-03-01

3D reconstruction of vessels from 2D X-ray angiography is highly relevant to improve the visualization and the assessment of vascular structures such as pulmonary arteries by interventional cardiologists. However, to ensure a robust and accurate reconstruction, C-arm gantry parameters must be properly calibrated to provide clinically acceptable results. Calibration procedures often rely on calibration objects and complex protocol which is not adapted to an intervention context. In this study, a novel calibration algorithm for C-arm gantry is presented using the instrumentation such as catheters and guide wire. This ensures the availability of a minimum set of correspondences and implies minimal changes to the clinical workflow. The method was evaluated on simulated data and on retrospective patient datasets. Experimental results on simulated datasets demonstrate a calibration that allows a 3D reconstruction of the guide wire up to a geometric transformation. Experiments with patients datasets show a significant decrease of the retro projection error to 0.17 mm 2D RMS. Consequently, such procedure might contribute to identify any calibration drift during the intervention.

[Clinical study on the coronary artery interventions guided by the magnetic navigation system].

PubMed

Li, Chun-jian; Wang, Hui; Wang, Lian-sheng; Zhu, Tie-bing; Yang, Zhi-jian; Cao, Ke-jiang

2010-03-01

To investigate the efficacy and safety of the magnetic navigation system used in the real world percutaneous coronary artery intervention. All lesions detected by the coronary artery angiography in the magnetic-navigation catheter lab indicated for percutaneous coronary artery intervention (PCI) were included and treated under the guidance of the magnetic navigation system. The characteristics of the target lesion, process of the procedure, time and dosage of the X-ray exposure, and procedure-related complication were recorded and analyzed. One hundred and twenty one patients with 138 lesions were recruited and intervened by PCI during the period from April 2006 to June 2008. Thirty lesions were classified as type A, 50 as type B1, 36 as type B2, 22 as type C (including seven total occlusions). The average stenosis of the target lesions was (85.3 +/- 10.0)%, mean length was (21.1 +/- 10.0) mm. Under the guidance of the magnetic navigation system, 134 target lesions were passed by the magnetic guide-wires, the lesion passing ratio was 97.1%. The X-ray exposure time, X-ray dosage and the contrast volume used during the period of the wire placement were (55.9 +/- 35.4) seconds, (98.0 +/- 86.1) mGy/(490.0 +/- 422.2) microGym(2) and (8.0 +/- 5.4) ml, respectively. A total of 164 stents were implanted in the vessels where the target lesions were passed by the magnetic wires. There was no magnetic navigation system associated complication. Magnetic guide-wires failed to pass four target lesions, two of which were chronic total occlusions (CTOs), and the other two were calcified subtotal occlusions. It is feasible and safe to adopt the magnetic navigation system for the real-world coronary artery intervention. The magnetic guide-wire possesses a high lesion-passing ratio. The CTOs and calcified subtotal occlusions are not ideal lesions for use of the magnetic navigation system.

Intraoperative Localisation of Impalpable Breast Lesions Utilising the ROLLIS Technique Following Peritumoral ^99mTc-colloid Sentinel Node Lymphoscintigraphy.

PubMed

Hung, Te-Jui; Burrage, John; Bourke, Anita; Taylor, Donna

2017-08-24

Ultrasound or stereotactic guided hook-wire localisation has been the standard-of-care for the pre-surgical localisation of impalpable breast lesions, which account for approximately a third of all breast cancer. Radioguided occult lesion localisation using I-125 seeds (ROLLIS) is a relatively new technique for guiding surgical excision of impalpable breast lesions, and is a promising alternative to the traditional hook-wire method. When combined with Tc-99m labelled colloid for sentinel node mapping in clinically indicated cases, there has been uncertainty regarding whether the downscatter of Tc-99m into the I-125 energy spectrum could adversely affect the intra-operative detection of the I-125 seed, especially pertaining to a peritumoral injection. To evaluate the percentage contribution of downscattered activity from Tc-99m into the I-125 energy spectrum in simulated intra-operative resections of an I-125 seed following different sentinel node injection techniques. Two scenarios were simulated using breast phantoms with lean chicken breast. The first scenario, with a 2cm distance between the Tc-99m injection site and the I-125 seed, simulated a periareolar ipsiquadrant injection with the subdermal or intradermal technique. The second scenario simulated a peritumoral injection technique with the Tc-99m bolus and an I-125 seed at the same site. Count rates were acquired with a hand-held gamma probe, and the percentage contribution of downscattered Tc-99m gamma photons to the I-125 energy window was calculated. In scenarios one and two, downscattered Tc-99m activity contributed 0.5% and 33% respectively to the detected count rate in the I-125 energy window. In both scenarios, the I-125 seed was successfully localised and removed using the gamma probe. There is no significant contribution of downscattered activity associated with a peritumoral injection of Tc-99m to adversely affect the accurate intra-operative localisation of an I- 125 seed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A Novel 'Cheese Wire' Technique for Stent Positioning Following Difficult Iliac Artery Subintimal Dissection and Aortic Re-Entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkinson, A. F., E-mail: anthony.watkinson@rdeft.nhs.u

2009-07-15

Subintimal wire dissection is a well-established method for traversing difficult vascular occlusions. This technique relies on re-entry of the true lumen distal to the occlusion, which may be difficult in diseased vessels with significant calcification. This case report describes a novel 'cheese wire' technique to allow stent positioning without the use of proprietary re-entry devices.

Tips of the dual-lumen microcatheter-facilitated reverse wire technique in percutaneous coronary interventions for markedly angulated bifurcated lesions.

PubMed

Nomura, Tetsuya; Kikai, Masakazu; Hori, Yusuke; Yoshioka, Kenichi; Kubota, Hiroshi; Miyawaki, Daisuke; Urata, Ryota; Sugimoto, Takeshi; Keira, Natsuya; Tatsumi, Tetsuya

2018-04-01

In practical settings of percutaneous coronary intervention (PCI), we sometimes encounter difficulty in introducing a guidewire (GW) to the markedly angulated side branch (SB), and the reverse wire technique is considered as a last resort to overcome such a situation. We analyzed 12 cases that underwent PCI with dual-lumen microcatheter-facilitated reverse wire technique between January 2013 and July 2016. We retrospectively investigated the lesion's characteristics and the details of the PCI procedures, and discussed tips about the use of this technique. The SB that exhibits both a smaller take-off angle and a larger carina angle is considered to be the most suitable candidate for this technique. The first step of this technique involves the delivery of the reverse wire system to the target bifurcation. However, most cases exhibit significant stenosis proximal to the bifurcation, which often hampers the delivery of the reverse wire system. Because the sharply curved reverse wire system is easier to pass the stenosis as compared to the roundly curved system, we recommend a sharp curve should be adopted for this technique. On the other hand, it is sure that device delivery is much easier on the GW with a round curve as compared to that with a sharp curve. Therefore, it is important to modify the details of this procedure on a case-by-case basis according to the lesion's characteristics.

Advanced signal processing methods applied to guided waves for wire rope defect detection

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Rostami, Javad

2016-02-01

Steel wire ropes, which are usually composed of a polymer core and enclosed by twisted wires, are used to hoist heavy loads. These loads are different structures that can be clamshells, draglines, elevators, etc. Since the loading of these structures is dynamic, the ropes are working under fluctuating forces in a corrosive environment. This consequently leads to progressive loss of the metallic cross-section due to abrasion and corrosion. These defects can be seen in the forms of roughened and pitted surface of the ropes, reduction in diameter, and broken wires. Therefore, their deterioration must be monitored so that any unexpected damage or corrosion can be detected before it causes fatal accident. This is of vital importance in the case of passenger transportation, particularly in elevators in which any failure may cause a catastrophic disaster. At present, the widely used methods for thorough inspection of wire ropes include visual inspection and magnetic flux leakage (MFL). Reliability of the first method is questionable since it only depends on the operators' eyes that fails to determine the integrity of internal wires. The later method has the drawback of being a point by point and time-consuming inspection method. Ultrasonic guided wave (UGW) based inspection, which has proved its capability in inspecting plate like structures such as tubes and pipes, can monitor the cross-section of wire ropes in their entire length from a single point. However, UGW have drawn less attention for defect detection in wire ropes. This paper reports the condition monitoring of a steel wire rope from a hoisting elevator with broken wires as a result of corrosive environment and fatigue. Experiments were conducted to investigate the efficiency of using magnetostrictive based UGW for rope defect detection. The obtained signals were analyzed by two time-frequency representation (TFR) methods, namely the Short Time Fourier Transform (STFT) and the Wavelet analysis. The location of the defect and its severity were successfully identified and characterized.

Measurements of the free stream fluctuations above a turbulent boundary layer

NASA Technical Reports Server (NTRS)

Wood, David H.; Westphal, Russell V.

1987-01-01

This paper investigates the velocity fluctuations in the free stream above an incompressible turbulent boundary layer developing at constant pressure. It is assumed that the fluctuations receive contributions from three statistically independent sources: (1) one-dimensional unsteadiness, (2) free stream turbulence, and (3) the potential motion induced by the turbulent boundary layer. Measurements were made in a wind tunnel with a root-mean-square level of the axial velocity fluctuations of about 0.2 percent. All three velocity components were measured using an X-wire probe. The unsteadiness was determined from the spanwise covariance of the axial velocity, measured using two single wire probes. The results show that it is possible to separate the contributions to the r.m.s. level of the velocity fluctuations, without resorting to the dubious technique of high-pass filtering. The separation could be extended to the spectral densities of the contributions, if measurements of sufficient accuracy were available. The Appendix provides a general guide for the measurement of small free stream fluctuation levels.

Use of Multiple Operatories in Dental Care Delivery.

DTIC Science & Technology

1982-02-01

07212 Repair Traumatic Wounds, Complex Under 5cm 2.6 07213 Repair Traumatic Wounds, Complex Over 5cm 5.3 07260 Cleft Palate Repair 10.6 07265 Cleft Lip ...Facial Prosthesis 18.5 05940 Implants 16.8 05950 Maxillary Inclined Plane or Occlusal Table 19.4 05955 Mandibular Guide Flange 16.8 05960 Palatal Lift...Passive Lingual or Palatal Wire 1.2 08446 Face Bow, J Hooks, Clinical Cup 1.2 08447 Active Lingual or Palatal Wire 1.2 08448 Multi-Stranded Wire 0.6 08510

Effects of line fiducial parameters and beamforming on ultrasound calibration

PubMed Central

Ameri, Golafsoun; Baxter, John S. H.; McLeod, A. Jonathan; Peters, Terry M.; Chen, Elvis C. S.

2017-01-01

Abstract. Ultrasound (US)-guided interventions are often enhanced via integration with an augmented reality environment, a necessary component of which is US calibration. Calibration requires the segmentation of fiducials, i.e., a phantom, in US images. Fiducial localization error (FLE) can decrease US calibration accuracy, which fundamentally affects the total accuracy of the interventional guidance system. Here, we investigate the effects of US image reconstruction techniques as well as phantom material and geometry on US calibration. It was shown that the FLE was reduced by 29% with synthetic transmit aperture imaging compared with conventional B-mode imaging in a Z-bar calibration, resulting in a 10% reduction of calibration error. In addition, an evaluation of a variety of calibration phantoms with different geometrical and material properties was performed. The phantoms included braided wire, plastic straws, and polyvinyl alcohol cryogel tubes with different diameters. It was shown that these properties have a significant effect on calibration error, which is a variable based on US beamforming techniques. These results would have important implications for calibration procedures and their feasibility in the context of image-guided procedures. PMID:28331886

Effects of line fiducial parameters and beamforming on ultrasound calibration.

PubMed

Ameri, Golafsoun; Baxter, John S H; McLeod, A Jonathan; Peters, Terry M; Chen, Elvis C S

2017-01-01

Ultrasound (US)-guided interventions are often enhanced via integration with an augmented reality environment, a necessary component of which is US calibration. Calibration requires the segmentation of fiducials, i.e., a phantom, in US images. Fiducial localization error (FLE) can decrease US calibration accuracy, which fundamentally affects the total accuracy of the interventional guidance system. Here, we investigate the effects of US image reconstruction techniques as well as phantom material and geometry on US calibration. It was shown that the FLE was reduced by 29% with synthetic transmit aperture imaging compared with conventional B-mode imaging in a Z-bar calibration, resulting in a 10% reduction of calibration error. In addition, an evaluation of a variety of calibration phantoms with different geometrical and material properties was performed. The phantoms included braided wire, plastic straws, and polyvinyl alcohol cryogel tubes with different diameters. It was shown that these properties have a significant effect on calibration error, which is a variable based on US beamforming techniques. These results would have important implications for calibration procedures and their feasibility in the context of image-guided procedures.

Wiring harnesses documented by punched-card technique

NASA Technical Reports Server (NTRS)

Hicks, W. W.; Kloezeman, W. G.

1970-01-01

Cards representing a connector are punched, sorted, and then used to printout wiring documentation for that connector. When wiring changes are made, new cards are punched and the wiring documentation is reprinted to reflect the latest configuration.

Fabrication of a smart air intake structure using shape memory alloy wire embedded composite

NASA Astrophysics Data System (ADS)

Jung, Beom-Seok; Kim, Min-Saeng; Kim, Ji-Soo; Kim, Yun-Mi; Lee, Woo-Yong; Ahn, Sung-Hoon

2010-05-01

Shape memory alloys (SMAs) have been actively studied in many fields utilizing their high energy density. Applying SMA wire-embedded composite to aerospace structures, such as air intake of jet engines and guided missiles, is attracting significant attention because it could generate a comparatively large actuating force. In this research, a scaled structure of SMA wire-embedded composite was fabricated for the air intake of aircraft. The structure was composed of several prestrained Nitinol (Ni-Ti) SMA wires embedded in ∩-shape glass fabric reinforced plastic (GFRP), and it was cured at room temperature for 72 h. The SMA wire-embedded GFRP could be actuated by applying electric current through the embedded SMA wires. The activation angle generated from the composite structure was large enough to make a smart air intake structure.

Wire-bonder-assisted integration of non-bondable SMA wires into MEMS substrates

NASA Astrophysics Data System (ADS)

Fischer, A. C.; Gradin, H.; Schröder, S.; Braun, S.; Stemme, G.; van der Wijngaart, W.; Niklaus, F.

2012-05-01

This paper reports on a novel technique for the integration of NiTi shape memory alloy wires and other non-bondable wire materials into silicon-based microelectromechanical system structures using a standard wire-bonding tool. The efficient placement and alignment functions of the wire-bonding tool are used to mechanically attach the wire to deep-etched silicon anchoring and clamping structures. This approach enables a reliable and accurate integration of wire materials that cannot be wire bonded by traditional means.

A survey of Canadian anesthesiologists' preferences in difficult intubation and "cannot intubate, cannot ventilate" situations.

PubMed

Wong, David T; Mehta, Arpan; Tam, Amanda D; Yau, Brian; Wong, Jean

2014-08-01

The purpose of this survey was to determine the equipment that anesthesiologists prefer in difficult tracheal intubation and "cannot intubate, cannot ventilate" (CICV) situations. A questionnaire was e-mailed to members of the Canadian Anesthesiologists' Society to ascertain their preferences, experience, and comfort level with regard to their use of airway equipment in difficult intubation and CICV situations in adult patients. A Chi square test was used to analyse the data. All reported P values are two-sided. Nine hundred ninety-seven of 2,532 questionnaires (39%) were returned. In an unanticipated difficult direct laryngoscopic intubation situation, 893 of 997 (90%) respondents chose a video laryngoscope as the first-choice rescue technique, while 41 (4%) and 21 (2%) of respondents chose a flexible bronchoscope and an intubating laryngeal mask airway device, respectively. The majority of anesthesiologists had experience and were comfortable with using a flexible bronchoscope or a video laryngoscope. Regarding CICV, 294 of 955 (31%) respondents stated that they had never encountered it. Wire-guided cricothyroidotomy was chosen as the first-choice surgical airway by 375 of 955 (39%) respondents, while intravenous catheter cricothyroidotomy and "defer to tracheostomy by surgeon" were selected by 266 (28%) and 215 (23%) respondents, respectively. Seven hundred eighty-five of 997 (78%) respondents were familiar with the exact steps of the American Society of Anesthesiologists' difficult airway algorithm, while 448 (47%) had attended an airway workshop within the past five years. In a difficult intubation situation, the most frequently selected first-choice airway device was a video laryngoscope, followed by a flexible bronchoscope. In a CICV situation, the most frequently selected first-choice surgical airway technique was a wire-guided cricothyroidotomy, followed by an intravenous catheter cricothyroidotomy.

Square-lashing technique in segmental spinal instrumentation: a biomechanical study.

PubMed

Arlet, Vincent; Draxinger, Kevin; Beckman, Lorne; Steffen, Thomas

2006-07-01

Sublaminar wires have been used for many years for segmental spinal instrumentation in scoliosis surgery. More recently, stainless steel wires have been replaced by titanium cables. However, in rigid scoliotic curves, sublaminar wires or simple cables can either brake or pull out. The square-lashing technique was devised to avoid complications such as cable breakage or lamina cutout. The purpose of the study was therefore to test biomechanically the pull out and failure mode of simple sublaminar constructs versus the square-lashing technique. Individual vertebrae were subjected to pullout testing having one of two different constructs (single loop and square lashing) using either monofilament wire or multifilament cables. Four different methods of fixation were therefore tested: single wire construct, square-lashing wiring construct, single cable construct, and square-lashing cable construct. Ultimate failure load and failure mechanism were recorded. For the single wire the construct failed 12/16 times by wire breakage with an average ultimate failure load of 793 N. For the square-lashing wire the construct failed with pedicle fracture in 14/16, one bilateral lamina fracture, and one wire breakage. Ultimate failure load average was 1,239 N For the single cable the construct failed 12/16 times due to cable breakage (average force 1,162 N). 10/12 of these breakages were where the cable looped over the rod. For the square-lashing cable all of these constructs (16/16) failed by fracture of the pedicle with an average ultimate failure load of 1,388 N. The square-lashing construct had a higher pullout strength than the single loop and almost no cutting out from the lamina. The square-lashing technique with cables may therefore represent a new advance in segmental spinal instrumentation.

Radiographic comparison of apical root resorption after orthodontic treatment between bidimensional and Roth straight-wire techniques

PubMed Central

Zawawi, Khalid H; Malki, Ghadah A

2014-01-01

Objective: The aim of this study was to compare the amount of root resorption after orthodontic treatment between the bidimensional and the Roth straight-wire techniques. Another objective was to compare the amount of root resorption in the whole sample studied and record the prevalence of root resorption. Materials and Methods: The sample consisted of 40 patients (age ranged between 11 and 18 years) with Angle Class II division 1 malocclusions, treated nonextraction. Twenty patients were treated with bidimensional technique and 20 with a 0.018-inch Roth straight-wire technique. Root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs. Results: The results demonstrated that the bidimensional and Roth straight-wire groups showed significant root resorption after treatment, 1.11 (0.17) and 0.86 (0.05), respectively, P < 0.001. When comparing the amount of root shortening between the bidimensional and Roth straight-wire groups, there was no significant difference between the mean change from pre- to post-treatment between bidimensional group (mean = 1.00 ± 1.34) and Roth straight-wire group (mean = 0.88 ± 0.86), P = 0.63. Considering the whole sample, there was no root resoprtion in 32.5% of the analysed teeth. There was only mild resorption in 56.2%, moderate in 8.8% and severe in only 2.5% of the teeth. Conclusions: Treatment with the bidimensional technique did not produce an increase in the amount of root resorption. The prevalence and amount of root resorption was similar between bidimensional and Roth straight-wire techniques. PMID:25426453

Radiographic comparison of apical root resorption after orthodontic treatment between bidimensional and Roth straight-wire techniques.

PubMed

Zawawi, Khalid H; Malki, Ghadah A

2014-10-01

The aim of this study was to compare the amount of root resorption after orthodontic treatment between the bidimensional and the Roth straight-wire techniques. Another objective was to compare the amount of root resorption in the whole sample studied and record the prevalence of root resorption. The sample consisted of 40 patients (age ranged between 11 and 18 years) with Angle Class II division 1 malocclusions, treated nonextraction. Twenty patients were treated with bidimensional technique and 20 with a 0.018-inch Roth straight-wire technique. Root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs. The results demonstrated that the bidimensional and Roth straight-wire groups showed significant root resorption after treatment, 1.11 (0.17) and 0.86 (0.05), respectively, P < 0.001. When comparing the amount of root shortening between the bidimensional and Roth straight-wire groups, there was no significant difference between the mean change from pre- to post-treatment between bidimensional group (mean = 1.00 ± 1.34) and Roth straight-wire group (mean = 0.88 ± 0.86), P = 0.63. Considering the whole sample, there was no root resoprtion in 32.5% of the analysed teeth. There was only mild resorption in 56.2%, moderate in 8.8% and severe in only 2.5% of the teeth. Treatment with the bidimensional technique did not produce an increase in the amount of root resorption. The prevalence and amount of root resorption was similar between bidimensional and Roth straight-wire techniques.

Fenestration of a Papyrus PK covered stent to recover the occluded left main bifurcation after sealing a left main perforation during a CTO procedure.

PubMed

Werner, Gerald S; Ahmed, Waqar H

2017-09-01

Covered stents are indicated for coronary perforations, but they may seal off major side branches in that process. We report the successful sealing of an ostial left main perforation, induced by a guide catheter in the course of a retrograde approach to treat a chronic total occlusion (CTO) of the right coronary artery (RCA) in a 76year old woman with prior CABG. The implanted Papyrus covered stent, however, overlapped the left main bifurcation and occluded the non-grafted circumflex artery (CX) resulting in acute ischemia. Through a double lumen catheter advanced over the wire located in the left anterior descending coronary artery (LAD) territory, a stiff recanalization wire could be advanced from the side-port to penetrate the stent membrane towards the CX. This was successfully achieved, and after subsequent dilatation, a drug-eluting stent was implanted in Culotte-fashion from the CX to the left main with subsequent kissing-balloon dilatation. The clinical symptoms subsided immediately, and the RCA was finally recanalized in antegrade parallel wire technique. No periprocedural infarct was observed during 48h of follow-up before discharge. At clinical follow-up of 6months the patient is symptom-free. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel data reduction technique for single slanted hot-wire measurements used to study incompressible compressor tip leakage flows

NASA Astrophysics Data System (ADS)

Berdanier, Reid A.; Key, Nicole L.

2016-03-01

The single slanted hot-wire technique has been used extensively as a method for measuring three velocity components in turbomachinery applications. The cross-flow orientation of probes with respect to the mean flow in rotating machinery results in detrimental prong interference effects when using multi-wire probes. As a result, the single slanted hot-wire technique is often preferred. Typical data reduction techniques solve a set of nonlinear equations determined by curve fits to calibration data. A new method is proposed which utilizes a look-up table method applied to a simulated triple-wire sensor with application to turbomachinery environments having subsonic, incompressible flows. Specific discussion regarding corrections for temperature and density changes present in a multistage compressor application is included, and additional consideration is given to the experimental error which accompanies each data reduction process. Hot-wire data collected from a three-stage research compressor with two rotor tip clearances are used to compare the look-up table technique with the traditional nonlinear equation method. The look-up table approach yields velocity errors of less than 5 % for test conditions deviating by more than 20 °C from calibration conditions (on par with the nonlinear solver method), while requiring less than 10 % of the computational processing time.

Causes of failure with Szabo technique - an analysis of nine cases.

PubMed

Jain, Rajendra Kumar; Padmanabhan, T N C; Chitnis, Nishad

2013-01-01

The objective of this case series is to identify and define causes of failure of Szabo technique in rapid-exchange monorail system for ostial lesions. From March 2009 to March 2011, 42 patients with an ostial lesion were treated percutaneously at our institution using Szabo technique in a monorail stent system. All patients received unfractionated heparin during intervention. Loading dose of clopidogrel, followed by clopidogrel and aspirin was administered. In 57% of patients, drug-eluting stents were used and in 42.8% patients bare metal stents. The stent was advanced over both wires, the target wire and the anchor wire. The anchor wire, which was passed through the proximal trailing strut of the stent helps to achieve precise stenting. The procedure was considered to be successful if stent was placed precisely covering the lesion and without stent loss or anchor wire prolapsing. Of the total 42 patients, the procedure was successful in 33, while failed in 9. Majority of failures were due to wire entanglement, which was fixed successfully in 3 cases by removing and reinserting the anchor wire. Out of other three failures, in one stent dislodgment occurred, stent could not cross the lesion in one and in another anchor wire got looped and prolapsed into target vessel. This case series shows that the Szabo technique, in spite of some difficulties like wire entanglement, stent dislodgement and resistance during stent advancement, is a simple and feasible method for treating variety of ostial lesions precisely compared to conventional angioplasty. Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Causes of failure with Szabo technique – An analysis of nine cases

PubMed Central

Jain, Rajendra Kumar; Padmanabhan, T.N.C.; Chitnis, Nishad

2013-01-01

Objective The objective of this case series is to identify and define causes of failure of Szabo technique in rapid-exchange monorail system for ostial lesions. Methods and results From March 2009 to March 2011, 42 patients with an ostial lesion were treated percutaneously at our institution using Szabo technique in a monorail stent system. All patients received unfractionated heparin during intervention. Loading dose of clopidogrel, followed by clopidogrel and aspirin was administered. In 57% of patients, drug-eluting stents were used and in 42.8% patients bare metal stents. The stent was advanced over both wires, the target wire and the anchor wire. The anchor wire, which was passed through the proximal trailing strut of the stent helps to achieve precise stenting. The procedure was considered to be successful if stent was placed precisely covering the lesion and without stent loss or anchor wire prolapsing. Of the total 42 patients, the procedure was successful in 33, while failed in 9. Majority of failures were due to wire entanglement, which was fixed successfully in 3 cases by removing and reinserting the anchor wire. Out of other three failures, in one stent dislodgment occurred, stent could not cross the lesion in one and in another anchor wire got looped and prolapsed into target vessel. Conclusion This case series shows that the Szabo technique, in spite of some difficulties like wire entanglement, stent dislodgement and resistance during stent advancement, is a simple and feasible method for treating variety of ostial lesions precisely compared to conventional angioplasty. PMID:23809379

Detection of structural damage in multiwire cables by monitoring the entropy evolution of wavelet coefficients

NASA Astrophysics Data System (ADS)

Ibáñez, Flor; Baltazar, Arturo; Mijarez, Rito; Aranda, Jorge

2015-03-01

Multiwire cables are widely used in important civil structures. Since they are exposed to several dynamic and static loads, their structural health can be compromised. The cables can also be submitted to mechanical contact, tension and energy propagation in addition to changes in size and material within their wires. Due to the critical role played by multiwire cables, it is necessary to develop a non-destructive health monitoring method to maintain their structure and proper performance. Ultrasonic inspection using guided waves is a promising non-destructive damage monitoring technique for rods, single wires and multiwire cables. The propagated guided waves are composed by an infinite number of vibrational modes making their analysis difficult. In this work, an entropy-based method to identify small changes in non-stationary signals is proposed. A system to capture and post-process acoustic signals is implemented. The Discrete Wavelet Transform (DWT) is computed in order to obtain the reconstructed wavelet coefficients of the signals and to analyze the energy at different scales. The feasibility of using the concept of entropy evolution of non-stationary signals to detect damage in multiwire cables is evaluated. The results show that there is a high correlation between the entropy value and damage level of the cable. The proposed method has low sensitivity to noise and reduces the computational complexity found in a typical time-frequency analysis.

A “Train-Track” Technique in Anatomic Reconstruction of SVC Bifurcation Complicated by Cardiac Tamponade: An Introspection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karuppasamy, Karunakaravel, E-mail: karuppk@ccf.org; Al-Natour, Mohammed, E-mail: mnatour85@msn.com; Gurajala, Ram Kishore, E-mail: gurajar@ccf.org

This report describes a stenting technique used to anatomically reconstruct superior vena cava (SVC) bifurcation in a patient with benign SVC syndrome. After recanalizing the SVC bifurcation, we exchanged two 0.035-in. wires for two 0.018-in. wires, deployed the SVC stent over these two wires (“train-track” technique), and stented each innominate vein over one wire. However, our decisions to recanalize both innominate veins, use the “buddy-wire” technique for SVC dilation, and dilate the SVC to 16 mm before stent deployment likely contributed to SVC tear, which was managed by resuscitation, SVC stent placement, and pericardial drainage. Here, we describe the steps ofmore » the train-track technique, which can be adopted to reconstruct other bifurcations; we also discuss the controversial aspects of this case.« less

A Vibrating Wire System For Quadrupole Fiducialization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, Zachary

2010-12-13

A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization stepmore » of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method of choice. We then give an overview of the measurement system showing how the vibrating wire is positioned onto the quadrupole axis, how the wire position detectors locate the wire relative to tooling balls without touching the wire, and how the tooling ball positions are all measured. The novel feature of this system is the vibrating wire which we discuss in depth. We analyze the wire dynamics and calculate the expected sensitivity of the system. The note should be an aid in debugging the system by providing calculations to compare measurements to.« less

V/sub 3/Ga wire fabricated by the modified jelly roll technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gubser, D.U.; Francavilla, T.L.; Pande, C.S.

V/sub 3/Ga wire has been fabricated by the modified jelly roll technique for the first time. Critical current densities in magnetic fields to 22 T, critical magnetic fields, and superconducting transition temperatures are reported for this wire as a function of reaction temperature for forming the interfacial V/sub 3/Ga layer. Superconducting properties of the reacted wire are optimized for reaction temperatures between 550--580 /sup 0/C. With a reaction temperature of 580 /sup 0/C, the overall (noncopper) current density of the wire is over 10/sup 4/ amp/cm/sup 2/ at 19 T.

Ultrasonography-guided central venous catheterisation in haematological patients with severe thrombocytopenia

PubMed Central

Napolitano, Mariasanta; Malato, Alessandra; Raffaele, Francesco; Palazzolo, Manuela; Iacono, Giorgio Lo; Pinna, Roberto; Geraci, Girolamo; Modica, Giuseppe; Saccullo, Giorgia; Siragusa, Sergio; Cajozzo, Massimo

2013-01-01

Background Cannulation of the internal jugular vein (CVC) is a blind surface landmark-guided technique that could be potentially dangerous in patients with very low platelet counts. In such patients, ultrasonography (US)-guided CVC may be a valid approach. There is a lack of published data on the efficacy and safety of urgent US-guided CVC performed in haematological patients with severe thrombocytopenia. Materials and methods We retrospectively studied the safety of urgent CVC procedures in haematological patients including those with severe thrombocytopenia (platelet count <30×109/L). From January 1999 to June 2009, 431 CVC insertional procedures in 431 consecutive patients were evaluated. Patients were included in the study if they had a haematological disorder and required urgent CVC insertion. Patients were placed in Trendelenburg's position, an 18-gauge needle and guide-wire were advanced under real-time US guidance into the last part of the internal jugular vein; central venous cannulation of the internal jugular vein was performed using the Seldinger technique in all the procedures. Major and minor procedure-related complications were recorded. Results All 431 patients studied had haematological disorders: 39 had severe thrombocytopenia, refractory to platelet transfusion (group 1), while 392 did not have severe thrombocytopenia (group 2). The general characteristics of the patients in the two groups differed only for platelet count. The average time taken to perform the procedure was 4 minutes. Success rates were 97.4% and 97.9% in group 1 and group 2, respectively. No major complications occurred in either group. Discussion US-guided CVC is a safe and effective approach in haematological patients with severe thrombocytopenia requiring urgent cannulation for life support, plasma-exchange, chemotherapy and transfusion. PMID:23399356

Magnetic resonance imaging-radioguided occult lesion localization (ROLL) in breast cancer using Tc-99m macro-aggregated albumin and distilled water control

PubMed Central

2013-01-01

Background Magnetic resonance imaging (MRI) guided wire localization presents several challenges apart from the technical difficulties. An alternative to this conventional localization method using a wire is the radio-guided occult lesion localization (ROLL), more related to safe surgical margins and reductions in excision volume. The purpose of this study was to establish a safe and reliable magnetic resonance imaging-radioguided occult lesion localization (MRI-ROLL) technique and to report our initial experience with the localization of nonpalpable breast lesions only observed on MRI. Methods Sixteen women (mean age 53.2 years) with 17 occult breast lesions underwent radio-guided localization in a 1.5-T MR system using a grid-localizing system. All patients had a diagnostic MRI performed prior to the procedure. An intralesional injection of Technetium-99m macro-aggregated albumin followed by distilled water was performed. After the procedure, scintigraphy was obtained. Surgical resection was performed with the help of a gamma detector probe. The lesion histopathology and imaging concordance; the procedure’s positive predictive value (PPV), duration time, complications, and accuracy; and the rate of exactly excised lesions evaluated with MRI six months after the surgery were assessed. Results One lesion in one patient had to be excluded because the radioactive substance came back after the injection, requiring a wire placement. Of the remaining cases, there were four malignant lesions, nine benign lesions, and three high-risk lesions. Surgical histopathology and imaging findings were considered concordant in all benign and high-risk cases. The PPV of MRI-ROLL was greater if the indication for the initial MR examination was active breast cancer. The median procedure duration time was 26 minutes, and all included procedures were defined as accurate. The exact and complete lesion removal was confirmed in all (100%) patients who underwent six-month postoperative MRI (50%). Conclusions MRI-ROLL offers a precise, technically feasible, safe, and rapid means for performing preoperative MRI localizations in the breast. PMID:24044428

How to read and write mechanical information in DNA molecules

NASA Astrophysics Data System (ADS)

Schiessel, Helmut

In this talk I will show that DNA molecules contain another layer of information on top of the classical genetic information. This different type of information is of mechanical nature and guides the folding of DNA molecules inside cells. With the help of a new Monte Carlo technique, the Mutation Monte Carlo method, we demonstrate that the two layers of information can be multiplexed (as one can have two phone conversations on the same wire). For instance, we can guide on top of genes with single base-pair precision the packaging of DNA into nucleosomes. Finally, we study the mechanical properties of DNA molecules belonging to organisms all across the tree of life. From this we learn that in multicellular organisms the stiffness of DNA around transcription start sites differs dramatically from that of unicellular life. The reason for this difference is surprising.

Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding.

PubMed

Goffin, N J; Higginson, R L; Tyrer, J R

2016-12-01

In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure.

Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding

PubMed Central

Higginson, R. L.; Tyrer, J. R.

2016-01-01

In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure. PMID:28119550

Improvement of modulation bandwidth in electroabsorption-modulated laser by utilizing the resonance property in bonding wire.

PubMed

Kwon, Oh Kee; Han, Young Tak; Baek, Yong Soon; Chung, Yun C

2012-05-21

We present and demonstrate a simple and cost-effective technique for improving the modulation bandwidth of electroabsorption-modulated laser (EML). This technique utilizes the RF resonance caused by the EML chip (i.e., junction capacitance) and bonding wire (i.e, wire inductance). We analyze the effects of the lengths of the bonding wires on the frequency responses of EML by using an equivalent circuit model. To verify this analysis, we package a lumped EML chip on the sub-mount and measure its frequency responses. The results show that, by using the proposed technique, we can increase the modulation bandwidth of EML from ~16 GHz to ~28 GHz.

Comparison of two tension-band fixation materials and techniques in transverse patella fractures: a biomechanical study.

PubMed

Rabalais, R David; Burger, Evalina; Lu, Yun; Mansour, Alfred; Baratta, Richard V

2008-02-01

This study compared the biomechanical properties of 2 tension-band techniques with stainless steel wire and ultra high molecular weight polyethylene (UHMWPE) cable in a patella fracture model. Transverse patella fractures were simulated in 8 cadaver knees and fixated with figure-of-8 and parallel wire configurations in combination with Kirschner wires. Identical configurations were tested with UHMWPE cable. Specimens were mounted to a testing apparatus and the quadriceps was used to extend the knees from 90 degrees to 0 degrees; 4 knees were tested under monotonic loading, and 4 knees were tested under cyclic loading. Under monotonic loading, average fracture gap was 0.50 and 0.57 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.16 and 0.04 mm, respectively, in the parallel wire construct. Under cyclic loading, average fracture gap was 1.45 and 1.66 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.45 and 0.60 mm, respectively, in the parallel wire construct. A statistically significant effect of technique was found, with the parallel wire construct performing better than the figure-of-8 construct in both loading models. There was no effect of material or interaction. In this biomechanical model, parallel wires performed better than the figure-of-8 configuration in both loading regimens, and UHMWPE cable performed similarly to 18-gauge steel wire.

Soft J-tipped guide wire-induced cardiac perforation in a patient with right ventricular lipomatosis and wall thinning.

PubMed

Hiroshima, Yuki; Tajima, Katsushi; Shiono, Yousuke; Suzuki, Ikuko; Kohno, Kei; Kato, Yuichi; Shunji, Kawamura; Kato, Takeo

2012-01-01

Cardiac tamponade caused by perforation is a rare but potentially lethal complication of central venous catheter (CVC) insertion. We herein report a case of cardiac perforation associated with the use of a soft J-tipped guide wire. Twenty minutes after the insertion of a CVC, the patient developed unexpected cardiac arrest. An autopsy revealed 400 mL of pericardial blood. The right ventricular wall was 1 mm thick with about 10 myocyte layers, which is one-third that of the normal heart. A histological analysis revealed widespread fatty infiltration of the right ventricular wall (right ventricular lipomatosis).

Micromachined actuators/sensors for intratubular positioning/steering

DOEpatents

Lee, Abraham P.; Krulevitch, Peter A.; Northrup, M. Allen; Trevino, Jimmy C.

1998-01-01

Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems.

Microvalve

DOEpatents

Lee, A.P.; Krulevitch, P.A.; Northrup, M.A.; Trevino, J.C.

1998-10-13

Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems. 14 figs.

Microvalve

DOEpatents

Lee, Abraham P.; Krulevitch, Peter A.; Northrup, M. Allen; Trevino, Jimmy C.

1998-01-01

Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems.

One-step endosonography-guided drainage of a pancreatic pseudocyst: a new technique of stent delivery through the echo endoscope.

PubMed

Vilmann, P; Hancke, S; Pless, T; Schell-Hincke, J D; Henriksen, F W

1998-10-01

We report here the first case of a one-step endosonography(EUS)-guided pseudocyst drainage. A prototype large channel curved array echo endoscope (Pentax FG-38 UX) and a prototype delivery system for placement of an endoprosthesis was used for the procedure. The delivery system (GIP MedicinTechnik GmbH/Medi-Globe Corporation) consists of a handle part with a piston, a metal ring sheath, a plastic catheter with a diathermy needle and a double pigtail endoprosthesis (8.5 Fr). When mounted on the endoscope the endoprosthesis can be advanced out of the distal end of the endoscope. The introduction of the stent as well as the stent release can be monitored entirely by ultrasound. The procedure was tested in a 76-year-old woman with a pseudocyst measuring 60 mm in diameter located in the tail of the pancreas. The procedure was well tolerated by the patient, and there were no procedural complications. The advantage of a large channel echo endoscope and our new prototype delivery system is that the endoprosthesis can be inserted in to a pancreatic cyst guided exclusively by EUS without exchange of endoscopes, catheters or guide wires. Further studies are warranted.

Apollo experience report: Electrical wiring subsystem

NASA Technical Reports Server (NTRS)

White, L. D.

1975-01-01

The general requirements of the electrical wiring subsystems and the problem areas and solutions that occurred during the major part of the Apollo Program are detailed in this report. The concepts and definitions of specific requirements for electrical wiring; wire-connecting devices; and wire-harness fabrication, checkout, and installation techniques are discussed. The design and development of electrical wiring and wire-connecting devices are described. Mission performance is discussed, and conclusions and recommendations for future programs are presented.

The Monorail Technique to Overcome Difficult Anatomical Course During Implantation of Central Venous Port via the Left Internal Jugular Vein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Eu Hyun, E-mail: doorihyun6@gmail.com; Oh, Jung Suk; Chun, Ho Jong

PurposeThe study aimed to introduce a monorail technique to overcome difficult anatomical course via left internal jugular vein in implantable port insertion.MethodsFrom 2007 to 2016, a total of 9346 patients were referred for implantable port insertion in our interventional unit, among which 79 cases were requested to insert on the left side. Our monorail technique was applied only when the technical challenge of the catheter tip entering the azygos vein instead of the superior vena cava occurred (n = 7). The technique consists of puncturing at the distal tip of the port catheter with a 21-gauge micropuncture needle and advancing a 0.018-in.more » hair-wire to guide and provide support for pre-assembled port.ResultsThe monorail technique was performed in seven patients and all but one case were technically successful, showing a technical success rate of 85.7%. There were no immediate or delayed complications.ConclusionsThe monorail technique is helpful to overcome the difficult anatomical course via left internal jugular vein in implantable port insertion.« less

The Monorail Technique to Overcome Difficult Anatomical Course During Implantation of Central Venous Port via the Left Internal Jugular Vein.

PubMed

Kim, Eu Hyun; Oh, Jung Suk; Chun, Ho Jong; Lee, Hae Giu; Choi, Byung Gil

2017-03-01

The study aimed to introduce a monorail technique to overcome difficult anatomical course via left internal jugular vein in implantable port insertion. From 2007 to 2016, a total of 9346 patients were referred for implantable port insertion in our interventional unit, among which 79 cases were requested to insert on the left side. Our monorail technique was applied only when the technical challenge of the catheter tip entering the azygos vein instead of the superior vena cava occurred (n = 7). The technique consists of puncturing at the distal tip of the port catheter with a 21-gauge micropuncture needle and advancing a 0.018-in. hair-wire to guide and provide support for pre-assembled port. The monorail technique was performed in seven patients and all but one case were technically successful, showing a technical success rate of 85.7%. There were no immediate or delayed complications. The monorail technique is helpful to overcome the difficult anatomical course via left internal jugular vein in implantable port insertion.

Outcomes of multiple wire localization for larger breast cancers: when can mastectomy be avoided?

PubMed

Kirstein, Laurie J; Rafferty, Elizabeth; Specht, Michelle C; Moore, Richard H; Taghian, Alphonse G; Hughes, Kevin S; Gadd, Michele A; Smith, Barbara L

2008-09-01

Mastectomy is often recommended when mammography shows a breast cancer with extensive calcifications. We wished to determine whether the use of multiple localizing wires to guide lumpectomy in this setting was associated with increased rates of breast conservation. We also wanted to identify factors that predicted a poor chance of successful lumpectomy, to avoid multiple lumpectomy attempts in a patient who would ultimately require mastectomy. Records of 153 women with breast cancer who underwent lumpectomy for larger lesions that required multiple wire localization and 196 controls who required only single wire localization were reviewed retrospectively. The number of localizing wires, specimen volume, largest specimen dimension, number of surgical procedures, and rates of breast conservation were scored. Seventy-seven percent of patients requiring multiple wire localization had successful breast conservation, compared with 90% of those needing only single wire localization. Only 28% of multiple wire patients required more than 1 excision to achieve clear margins, compared with 36% of single wire patients (p < 0.01). Breast conservation is possible in the great majority of breast cancer patients whose mammographic lesions require multiple localizing wires for excision. The use of multiple wires can decrease the number of procedures required to obtain clear lumpectomy margins.

Wire harness twisting aid

NASA Technical Reports Server (NTRS)

Casey, E. J.; Commadore, C. C.; Ingles, M. E.

1980-01-01

Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

Mini-STAR as bail-out strategy for percutaneous coronary intervention of chronic total occlusion.

PubMed

Galassi, Alfredo Ruggero; Tomasello, Salvatore Davide; Costanzo, Luca; Campisano, Maria Barbara; Barrano, Giombattista; Ueno, Masafumi; Tello-Montoliu, Antonio; Tamburino, Corrado

2012-01-01

Although the advancement of the equipment and the presence of innovative techniques, percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) continues to be affected by lower procedural success in comparison with non occluded vessel PCI. We describe a new technique for the treatment of coronary CTO which utilizes a new generation of polymeric wires. From March 2009 to June 2010 different strategies were adopted as "bail out" after an initial attempt failed in 117 consecutive CTO lesions. Among these, conventional strategies (CS) such as parallel wire, sub-intimal tracking and re-entry (STAR), microchannel technique, intracoronary ultrasound guided revascularization and anchor balloon, were used in 75 cases (64.1%), while in the remaining a new technique, the "mini-STAR," was used (39.9%). Although no substantial differences were observed regarding the distribution of clinical features and angiographic lesions characteristics between the populations, mini-STAR was able to achieve a higher rate of procedural success in comparison with other CS (97.6% vs. 52%, P < 0.001) with lower contrast agent use (442 ± 259 cm(3) vs. 561 ± 243 cm(3), P = 0.01) and shorter procedural and fluoroscopy times (122 ± 61 vs. 157 ± 74 min, P = 0.009 and 60 ± 31 min vs. 75 ± 38 min, P = 0.03, respectively). No differences were observed in term of peri-procedural complications such as procedural myocardial infarction, coronary perforations, and contrast-induced nephropathy between mini-STAR and CS. The mini-STAR technique is a promising strategy for the treatment of CTO lesions, achieving a high procedural success rate and low occurrence of procedural adverse events. Copyright © 2011 Wiley Periodicals, Inc.

[Kirschner wire osteosynthesis for fractures in childhood: bury wires or not? : Results of a survey on care reality in Germany].

PubMed

Schneidmueller, D; Kertai, M; Bühren, V; von Rüden, C

2018-02-20

Kirschner wire osteosynthesis is considered to be the standard technique for surgical fixation of displaced supracondylar humeral and distal radial fractures in children. The Kirschner wires can be left exposed or buried under the skin. Advantages of the epicutaneous technique are, e. g. the efficiency (cost, effort) and the possibility for wire removal without the necessity of a second anesthesia. On the other hand, there is a concern about higher infection rates as well as traumatization of the children due to externally visible wires. A web-based survey of members of the DGU, DGOU, DGOOC, and the pediatric traumatology section of the DGU (SKT) was performed to evaluate current treatment concepts in Germany. The pros and cons for each technique were recorded and the need for a clinical study was examined. In addition, a cost analysis was performed for both methods. The results from the literature are summarized and discussed. A total of 710 questionnaires were evaluated. The majority of the respondents were trauma surgeons working in a hospital (80%). The buried technique was superior in both fracture groups (supracondylar humeral fractures 73% and distal radius fractures 69%), whereas a relevant difference could be found depending on the profession. The main reason for the subcutaneous technique was anxiety or observed higher infections using the epicutaneous technique. In Germany, the majority of wires are buried under the skin due to a fear of higher infection rates. In addition, other influencing factors such as pain and traditional approaches play a significant role. With respect to the results in the literature as well as a possible improvement of efficiency and avoidance of a second anesthesia, a multicentric clinical study seems necessary in the future to compare both techniques.

Investigation of ball bond integrity for 0.8 mil (20 microns) diameter gold bonding wire on low k die in wire bonding technology

NASA Astrophysics Data System (ADS)

Kudtarkar, Santosh Anil

Microelectronics technology has been undergoing continuous scaling to accommodate customer driven demand for smaller, faster and cheaper products. This demand has been satisfied by using novel materials, design techniques and processes. This results in challenges for the chip connection technology and also the package technology. The focus of this research endeavor was restricted to wire bond interconnect technology using gold bonding wires. Wire bond technology is often regarded as a simple first level interconnection technique. In reality, however, this is a complex process that requires a thorough understanding of the interactions between the design, material and process variables, and their impact on the reliability of the bond formed during this process. This research endeavor primarily focused on low diameter, 0.8 mil thick (20 mum) diameter gold bonding wire. Within the scope of this research, the integrity of the ball bond formed by 1.0 mil (25 mum) and 0.8 mil (20 mum) diameter wires was compared. This was followed by the evaluation of bonds formed on bond pads having doped SiO2 (low k) as underlying structures. In addition, the effect of varying the percentage of the wire dopant, palladium and bonding process parameters (bonding force, bond time, ultrasonic energy) for 0.8 mil (20 mum) bonding wire was also evaluated. Finally, a degradation empirical model was developed to understand the decrease in the wire strength. This research effort helped to develop a fundamental understanding of the various factors affecting the reliability of a ball bond from a design (low diameter bonding wire), material (low k and bonding wire dopants), and process (wire bonding process parameters) perspective for a first level interconnection technique, namely wire bonding. The significance of this research endeavor was the systematic investigation of the ball bonds formed using 0.8 mil (20 microm) gold bonding wire within the wire bonding arena. This research addressed low k structures on 90 nm silicon technology, bonding wires with different percentage of doping element (palladium), and different levels of bonding process parameters. An empirical model to understand the high temperature effects for bonds formed using the low diameter wire was also developed.

Strength of cerclage fixation systems: a biomechanical study.

PubMed

Incavo, S J; Difazio, F; Wilder, D

1990-11-01

This study examined the load to failure ratio and stiffness of eight different cerclage techniques commonly used in the clinical management of fractures. For a single-loop cerclage, titanium cable was the strongest, while stainless steel wire secured with a commercial tightener was the weakest (P < 0.05). When a single-loop configuration is necessary (i.e. trochanteric attachment) a cable system is superior to cerclage wiring. A double-wrap of either cable or wire was considerably stronger than any single-wrap cerclage technique and stronger than two cerclage wires (P < 0.05). Copyright © 1990. Published by Elsevier Ltd.

Modified tension band wiring of medial malleolar ankle fractures.

PubMed

Georgiadis, G M; White, D B

1995-02-01

Twenty-two displaced medial malleolar ankle fractures that were treated surgically using the modified tension band method of Cleak and Dawson were retrospectively reviewed at an average follow-up of 25 months. The technique involves the use of a screw to anchor a figure-of-eight wire. There were no malreductions and all fractures healed. Problems with the technique included technical errors with hardware placement, medial ankle pain, and asymptomatic wire migration. Despite this, modified tension band wiring remains an acceptable method for fixation of selected displaced medial malleolar fractures. It is especially suited for small fracture fragments and osteoporotic bone.

Stabilization of Olecranon Fractures by Tension Band Wiring or Plate Osteosynthesis: A Retrospective Study of 41 Cases.

PubMed

Fournet, Alexandre; Boursier, Jean-François; Corbeau, Solène; Decambron, Adeline; Viateau, Véronique; Fayolle, Pascal; Bedu, Anne-Sophie; Leperlier, Dimitri; Manassero, Mathieu

2018-01-01

 This article aimed to describe olecranon fracture in dogs and cats and their stabilization with tension band wiring or plate osteosynthesis, and to evaluate complications associated with each technique.  Medical records of cats and dogs that had been surgically treated for olecranon fractures with either tension band wiring or plate osteosynthesis were retrospectively reviewed. The surgical technique, complications and long-term outcomes were assessed.  Forty-one olecranon fractures were included. Fractures were articular, comminuted and open in 90, 31 and 27% of cases, respectively. Tension band wiring and plate osteosynthesis were performed in 22 and 19 fractures, respectively. Complications occurred more commonly after tension band wiring (74%) compared with plate osteosynthesis (27%) ( p  = 0.002) and these were probably related to it being used in comminuted fractures ( p  = 0.01) or to errors in technique. Minor complications included Kirschner wires migration ( n  = 5), pain ( n  = 3), osteomyelitis ( n  = 3), skin breakdown ( n  = 3) and seroma ( n  = 1). Implant failure requiring further fixation ( n  = 4) was observed only in the tension band wiring group. Other major complications included skin wound debridement and closure ( n  = 1) and chronic lameness requiring implant removal ( n  = 7). Long-term functional outcomes were excellent regardless of the technique used.  Plate osteosynthesis should be performed for olecranon fracture repair if technically feasible. Schattauer GmbH Stuttgart.

Micromachined actuators/sensors for intratubular positioning/steering

DOEpatents

Lee, A.P.; Krulevitch, P.A.; Northrup, M.A.; Trevino, J.C.

1998-06-30

Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems. 14 figs.

Uprighting Bilateral Impacted Mandibular Permanent Second Molars with the Brass Wire Technique: A Case Report.

PubMed

Perdigão, João Paulo Veloso; Lustosa, Romulo Maciel; Tolentino, Elen de Souza; Iwaki Filho, Liogi; Iwaki, Lilian Cristina Vessoni

2016-01-01

Revalence of impaction of mandibular permanent second molars is between 0.06 and 2.3 percent. In order to reduce treatment time and complications associated with tooth impaction, intervention should take place once the problem is detected. The usual treatment options consists of surgical exposure, luxation of the impacted tooth, extraction of adjacent third molar, orthodontic treatment, and uprighting with brass wires or mini-screws. The present paper reports a case of bilateral impaction of mandibular permanent second molars ' (MM2s) treated with extraction of the mandibular third molars (MM3s) and surgical-orthodontic uprighting with the brass wire technique. The MM3s were removed, and the impacted MM2s were surgically exposed. Brass wire was placed apicaly to the mesial of the MM2 from the lingual tissue out toward the buccal. The lingual end of the wire was bent over the area of contact and twisted with the buccal end Monthly wire tightening gradually moved the MM2s distally and towards the occlusal plane. Uprighting was achieved in 4-5 months, with discrete pain caused by activation of the wire. This technique proved to be a simple, low-cost, and quick treatment option for uprighting impacted mandibular permanent second molars.

Ultrasonics Equipped Crimp Tool: A New Technology for Aircraft Wiring Safety

NASA Technical Reports Server (NTRS)

Yost, William T.; Perey, Daniel F.; Cramer, Elliott

2006-01-01

We report on the development of a new measurement technique to quantitatively assess the condition of wire crimp connections. This ultrasonic (UT) method transmits high frequency sound waves through the joint under inspection. The wire-crimp region filters and scatters the ultrasonic energy as it passes through the crimp and wire. The resulting output (both time and frequency domains) provides a quantitative measure of the joint quality that is independent and unaffected by current. Crimps of poor mechanical and electrical quality will result in low temporal output and will distort the spectrum into unique and predictable patterns, depending on crimp "quality". This inexpensive, real-time measurement system can provide certification of crimps as they are made and recertification of existing wire crimps currently in service. The measurements for re-certification do not require that the wire be disconnected from its circuit. No other technology exists to measure in-situ the condition of wire joints (no electrical currents through the crimp are used in this analytical technique). We discuss the signals obtained from this instrument, and correlate these signals with destructive wire pull tests.

A Potential Pitfall in the Use of the Monorail System for Carotid Stenting

PubMed Central

Pereira, E.; Birnbaum, L.

2006-01-01

Summary The use of EPDs seems to be necessary for safe CAS. Though the monorail system may offer advantages for a single operator, we caution its use with certain aortic arch anatomies. In such anatomies, using an OTW system or at least a 300 cm filter wire or devices that support wire extension will remedy some complications, such as the loss of the guiding sheath. As in our case, the added advantage of a 300 cm filter wire enabled us to avoid a poor outcome or an emergency vascular surgery. PMID:20569594

A potential pitfall in the use of the monorail system for carotid stenting. A technical case report.

PubMed

Pereira, E; Birnbaum, L

2006-12-15

The use of EPDs seems to be necessary for safe CAS. Though the monorail system may offer advantages for a single operator, we caution its use with certain aortic arch anatomies. In such anatomies, using an OTW system or at least a 300 cm filter wire or devices that support wire extension will remedy some complications, such as the loss of the guiding sheath. As in our case, the added advantage of a 300 cm filter wire enabled us to avoid a poor outcome or an emergency vascular surgery.

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs)

PubMed Central

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-01-01

Case series Patient: Male, 81 • Female, 72 • Male, 58 Final Diagnosis: CTO Symptoms: Angina pectoris Medication: — Clinical Procedure: PCI Specialty: Cardiology Objective: Unusual setting of medical care Background: Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. Case Report: We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. Conclusions: The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations. PMID:28456814

Repair of olecranon fractures using fiberWire without metallic implants: report of two cases.

PubMed

Nimura, Akimoto; Nakagawa, Teruhiko; Wakabayashi, Yoshiaki; Sekiya, Ichiro; Okawa, Atsushi; Muneta, Takeshi

2010-10-12

Olecranon fractures are a common injury in fractures. The tension band technique for olecranon fractures yields good clinical outcomes; however, it is associated with significant complications. In many patients, implants irritate overlying soft tissues and cause pain. This is mostly due to protrusion of the proximal ends of the K-wires or by the twisted knots of the metal wire tension band. Below we described 2 cases of olecranon fractures treated with a unique technique using FiberWire without any metallic implants. Technically, the fragment was reduced, and two K-wires were inserted from the dorsal cortex of the distal segment to the tip of the olecranon. K-wire was exchanged for a suture retriever, and 2 strands of FiberWire were retrieved twice. Each of the two FiberWires was manually tensioned and knotted on the posterior surface of the olecranon. Bony unions could be achieved, and patients had no complaint of pain and skin irritation. There was only a small loss of flexion and extension in comparison with that of the contralateral side, and the patient did not feel inconvenienced in his daily life. Using the method described, difficulty due to K-wire or other metallic implants was avoided.

Attachment of Free Filament Thermocouples for Temperature Measurements on CMC

NASA Technical Reports Server (NTRS)

Lei, Jih-Fen; Cuy, Michael D.; Wnuk, Stephen P.

1997-01-01

Ceramic Matrix Composites (CMC) are being developed for use as enabling materials for advanced aeropropulsion engine and high speed civil transport applications. The characterization and testing of these advanced materials in hostile, high-temperature environments require accurate measurement of the material temperatures. Commonly used wire Thermo-Couples (TC) can not be attached to this ceramic based material via conventional spot-welding techniques. Attachment of wire TC's with commercially available ceramic cements fail to provide sufficient adhesion at high temperatures. While advanced thin film TC technology provides minimally intrusive surface temperature measurement and has good adhesion on the CMC, its fabrication requires sophisticated and expensive facilities and is very time consuming. In addition, the durability of lead wire attachments to both thin film TC's and the substrate materials requires further improvement. This paper presents a newly developed attachment technique for installation of free filament wire TC's with a unique convoluted design on ceramic based materials such as CMC's. Three CMC's (SiC/SiC CMC and alumina/alumina CMC) instrumented with type IC, R or S wire TC's were tested in a Mach 0.3 burner rig. The CMC temperatures measured from these wire TC's were compared to that from the facility pyrometer and thin film TC's. There was no sign of TC delamination even after several hours exposure to 1200 C. The test results proved that this new technique can successfully attach wire TC's on CMC's and provide temperature data in hostile environments. The sensor fabrication process is less expensive and requires very little time compared to that of the thin film TC's. The same installation technique/process can also be applied to attach lead wires for thin film sensor systems.

Recent developments in multi-wire fixed abrasive slicing technique (FAST). [for low cost silicon wafer production from ingots

NASA Technical Reports Server (NTRS)

Schmid, F.; Khattak, C. P.; Smith, M. B.; Lynch, L. D.

1982-01-01

Slicing is an important processing step for all technologies based on the use of ingots. A comparison of the economics of three slicing techniques shows that the fixed abrasive slicing technique (FAST) is superior to the internal diameter (ID) and the multiblade slurry (MBS) techniques. Factors affecting contact length are discussed, taking into account kerf width, rocking angle, ingot size, and surface speed. Aspects of blade development are also considered. A high concentration of diamonds on wire has been obtained in wire packs usd for FAST slicing. The material removal rate was found to be directly proportional to the pressure at the diamond tips.

Connecting to Thermocouples with Fewer Lead Wires

NASA Technical Reports Server (NTRS)

Goldsby, Jon C.

2003-01-01

A simple technique has been devised to reduce the number of lead wires needed to connect an array of thermocouples to the instruments (e.g., voltmeters) used to read their output voltages. Because thermocouple wires are usually made of expensive metal alloys, reducing the number of lead wires can effect a considerable reduction in the cost of such an array. Reducing the number of wires also reduces the number of terminals and the amount of space needed to accommodate the wires.

Wire EDM for Refractory Materials

NASA Technical Reports Server (NTRS)

Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

1982-01-01

In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

Small-bore wire-guided chest drains: safety, tolerability, and effectiveness in pneumothorax, malignant effusions, and pleural empyema.

PubMed

Cafarotti, Stefano; Dall'Armi, Valentina; Cusumano, Giacomo; Margaritora, Stefano; Meacci, Elisa; Lococo, F; Vita, M L; Porziella, V; Bonassi, S; Cesario, Alfredo; Granone, Pierluigi

2011-03-01

The use of small-bore wire-guided chest drains for pleural effusions and pneumothorax has become popular; however, limited data are available on its efficacy and morbidity. The aim of this retrospective study is to measure, via the analysis of the so far largest reported cohort, the efficacy, safety, and tolerability of this approach in different clinical conditions. In the period from January 2002 to December 2008, 1092 patients have undergone the positioning of a small-bore wire-guided chest drain (12F) for the evidence of pneumothorax or pleural effusion and have been monitored over time for morbidity, pain at the time of insertion (measured via the visual analogue scale), and drain failure for misplacement or blockage. Patients with trauma were excluded from this study. Male/female ratio and mean age were respectively 418:674 and 55.85 ± 18.6. Three-hundred ninety-nine (36.5%) drains were inserted for pneumothorax, 324 (29.7%) for malignant effusion, 97 (8.9%) for empyema, and 272 (24.9%) for nonmalignant effusion. The pain experience was on average "very mild" (mean visual analogue scale = 4.6 mm). The overall drain failure rate was 12.9%. The percentage of successful cases was 93.8% in malignant effusion, 93% in pneumothorax, and 92.3% in nonmalignant effusion; in the cases of pathologically diagnosed empyema, drains were more likely to get blocked (74.2%). We recorded 1 serious complication within the malignant effusion group. Wire-guided 12F Seldinger-type drains are a well-tolerated and effective method of treating pneumothorax and uncomplicated pleural effusions (malignant and nonmalignant) with acceptable morbidity. The use of 12F small-bore chest drain is not indicated for the treatment of empyema. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Navigation with Electromagnetic Tracking for Interventional Radiology Procedures

PubMed Central

Wood, Bradford J.; Zhang, Hui; Durrani, Amir; Glossop, Neil; Ranjan, Sohan; Lindisch, David; Levy, Eliott; Banovac, Filip; Borgert, Joern; Krueger, Sascha; Kruecker, Jochen; Viswanathan, Anand; Cleary, Kevin

2008-01-01

PURPOSE To assess the feasibility of the use of preprocedural imaging for guide wire, catheter, and needle navigation with electromagnetic tracking in phantom and animal models. MATERIALS AND METHODS An image-guided intervention software system was developed based on open-source software components. Catheters, needles, and guide wires were constructed with small position and orientation sensors in the tips. A tetrahedral-shaped weak electromagnetic field generator was placed in proximity to an abdominal vascular phantom or three pigs on the angiography table. Preprocedural computed tomographic (CT) images of the phantom or pig were loaded into custom-developed tracking, registration, navigation, and rendering software. Devices were manipulated within the phantom or pig with guidance from the previously acquired CT scan and simultaneous real-time angiography. Navigation within positron emission tomography (PET) and magnetic resonance (MR) volumetric datasets was also performed. External and endovascular fiducials were used for registration in the phantom, and registration error and tracking error were estimated. RESULTS The CT scan position of the devices within phantoms and pigs was accurately determined during angiography and biopsy procedures, with manageable error for some applications. Preprocedural CT depicted the anatomy in the region of the devices with real-time position updating and minimal registration error and tracking error (<5 mm). PET can also be used with this system to guide percutaneous biopsies to the most metabolically active region of a tumor. CONCLUSIONS Previously acquired CT, MR, or PET data can be accurately codisplayed during procedures with reconstructed imaging based on the position and orientation of catheters, guide wires, or needles. Multimodality interventions are feasible by allowing the real-time updated display of previously acquired functional or morphologic imaging during angiography, biopsy, and ablation. PMID:15802449

Comparison of conditional sampling and averaging techniques in a turbulent boundary layer

NASA Astrophysics Data System (ADS)

Subramanian, C. S.; Rajagopalan, S.; Antonia, R. A.; Chambers, A. J.

1982-10-01

A rake of cold wires was used in a slightly heated boundary layer to identify coherent temperature fronts. An X-wire/cold-wire arrangement was used simultaneously with the rake to provide measurements of the longitudinal and normal velocity fluctuations and temperature fluctuations. Conditional averages of these parameters and their products were obtained by application of conditional techniques (VITA, HOLE, BT, RA1, and RA3) based on the detection of temperature fronts using information obtained at only one point in space. It is found that none of the one-point detection techniques is in good quantitative agreement with the rake detection technique, the largest correspondence being 51%. Despite the relatively poor correspondence between the conditional techniques, these techniques, with the exception of HOLE, produce conditional averages that are in reasonable qualitative agreement with those deduced using the rake.

Safe intramedullary fixation of displaced midshaft clavicle fractures with 2.5mm Kirschner wires - technique description and a two-part versus multifragmentary fracture fixation outcome comparison.

PubMed

Bakota, Bore; Chan, Gareth; Staresinic, Mario; Rajput, Vishal; Phadnis, Joideep; Korac, Zelimir

2017-11-01

The aim of this study was to present a modified Murray and Schwarz 2.5-mm Kirschner wire (K-wire) intramedullary (IM) technique for fixation of displaced midshaft clavicle fractures (DMCF), and to compare the differences in treatment outcome of two-part (Robinson 2B.1) and multifragmentary (Robinson 2B.2) DMCF. A retrospective analysis of 91 patients who underwent IM fixation with a 2.5-mm K-wire for DMCF and had a 1-year post-operative follow-up between 2000 and 2012 was performed. The patients were allocated into two groups: Robinson 2B.1 (n = 64) and Robinson 2B.2 (n = 27). Assessed outcomes were non-union, reoperation rate, wire migration and infection. There was no statistically significant difference in the rate of non-union (2B.1,2B.2; 3.13%, 7.41%; p = 0.365), reoperation (2B.1, 2B.2; 3.13%, 7.41%; p = 0.365), K-wire migration (2B.1, 2B.2; 0.00%, 0.00%; p = 1.00) and clavicle shortening at 12-months (2B.1, 2B.2; 3.13%, 7.41%; p = 0.365). Intramedullary clavicle fixation with a 2.5-mm K-wire is a safe surgical technique. 2B.1 injuries treated with 2.5-mm IM K-wire fixation have relatively improved outcome compared with displaced 2B.2 fractures for both non-union and reoperation rates. There were no occurrences of implant migration with either 2B.1 or 2B.2 injuries, and a non-significant difference in implant irritation was documented with IM K-fixation. The non-union rate with K-wire IM fixation of 2B.1 injuries concords with the published results of other IM devices and thus this technique should be added to the surgeon's armamentarium when considering surgical treatment of such injuries. © 2017 Elsevier Ltd. All rights reserved.

Kirschner wire bending.

PubMed

Firoozabadi, Reza; Kramer, Patricia A; Benirschke, Stephen K

2013-11-01

Although Kirschner wires are useful implants in many situations, migration of the wire and irritation of the surrounding soft tissues are common complications. Seven steps are described herein, which result in a Kirschner wire that is bent 180° angle, providing a smooth anchor into bone. Use of this technique produces implants that provide stable fixation with few soft tissue complications.

Reliability Criteria for Thick Bonding Wire.

PubMed

Dagdelen, Turker; Abdel-Rahman, Eihab; Yavuz, Mustafa

2018-04-17

Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

Reliability Criteria for Thick Bonding Wire

PubMed Central

Yavuz, Mustafa

2018-01-01

Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire. PMID:29673194

Evaluating Thermally Damaged Polyimide Insulated Wiring (MIL-W-81381) with Ultrasound

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Anastasi, Robert F.

2002-01-01

A series of experiments to investigate the use of ultrasound for measuring wire insulation have been conducted. Initial laboratory tests were performed on MIL-W-81381/7,/12, and /21 aviation wire, a wire that has polyimide (Kapton Registered Trademark) layers for insulation. Samples of this wiring were exposed to 370C temperatures for different periods of time to induce a range of thermal damage. For each exposure, 12 samples of each gauge (12, 16, and 20 gauges) were processed. The velocity of the lowest order axisymmetric ultrasonic guided mode, a mode that is sensitive to the geometry and stiffness of the wire conductor and insulation, was measured. The phase velocity for the 20-gauge MIL-W-81381/7 wire had a baseline value of 3023 +/- 78 m/s. After exposure to the high temperatures, the wire's phase velocity rapidly increased, and reached an asymptotic value of 3598 +/- 20 m/s after 100 hours exposure. Similar behavior was measured for the 16 gauge MIL-W-81381/21 wire and 12 gauge MIL-W-81381/12 wire which had baseline values of 3225 +/- 22 m/s and 3403 +/- 33 m/s respectively, and reached asymptotic values of 3668 +/- 19 m/s, and 3679 +/- 42 m/s respectively. These measured velocity changes represent changes of 19, 14, and 8 percent respectively for the 20, 16, and 12 gauge wires. Finally, some results for a wire with an ethylene tetrafluoroethylene insulation are reported. Qualitatively similar behaviors are noted ultrasonically.

[Individual indirect bonding technique (IIBT) using set-up model].

PubMed

Kyung, H M

1989-01-01

There has been much progress in Edgewise Appliance since E.H. Angle. One of the most important procedures in edgewise appliance is correct bracket position. Not only conventional edgewise appliance but also straight wire appliance & lingual appliance cannot be used more effectively unless the bracket position is accurate. Improper bracket positioning may reveal much problems during treatment, especially in finishing state. It may require either rebonding after the removal of the malpositioned bracket or the greater number of arch wire and the more complex wire bending, causing much difficulty in performing effective treatments. This made me invent Individual Indirect Bonding Technique with the use of multi-purpose set-up model in order to determine a correct and objective bracket position according to individual patients. This technique is more accurate than former indirect bonding techniques in bracket positioning, because it decides the bracket position on a set-up model which has produced to have the occlusal relationship the clinician desired. This technique is especially effective in straight wire appliance and lingual appliance in which the correct bracket positioning is indispensible.

On the electromagnetic scattering from infinite rectangular conducting grids

NASA Technical Reports Server (NTRS)

Christodoulou, C.

1985-01-01

The study and development of two numerical techniques for the analysis of electromagnetic scattering from a rectangular wire mesh are described. Both techniques follow from one basic formulation and they are both solved in the spectral domain. These techniques were developed as a result of an investigation towards more efficient numerical computation for mesh scattering. These techniques are efficient for the following reasons: (a1) make use of the Fast Fourier Transform; (b2) they avoid any convolution problems by converting integrodifferential equations into algebraic equations; and (c3) they do not require inversions of any matrices. The first method, the SIT or Spectral Iteration Technique, is applied for regions where the spacing between wires is not less than two wavelengths. The second method, the SDCG or Spectral Domain Conjugate Gradient approach, can be used for any spacing between adjacent wires. A study of electromagnetic wave properties, such as reflection coefficient, induced currents and aperture fields, as functions of frequency, angle of incidence, polarization and thickness of wires is presented. Examples and comparisons or results with other methods are also included to support the validity of the new algorithms.

Development of a new technique for pedicle screw and Magerl screw insertion using a 3-dimensional image guide.

PubMed

Kawaguchi, Yoshiharu; Nakano, Masato; Yasuda, Taketoshi; Seki, Shoji; Hori, Takeshi; Kimura, Tomoatsu

2012-11-01

We developed a new technique for cervical pedicle screw and Magerl screw insertion using a 3-dimensional image guide. In posterior cervical spinal fusion surgery, instrumentation with screws is virtually routine. However, malpositioning of screws is not rare. To avoid complications during cervical pedicle screw and Magerl screw insertion, the authors developed a new technique which is a mold shaped to fit the lamina. Cervical pedicle screw fixation and Magerl screw fixation provide good correction of cervical alignment, rigid fixation, and a high fusion rate. However, malpositioning of screws is not a rare occurrence, and thus the insertion of screws has a potential risk of neurovascular injury. It is necessary to determine a safe insertion procedure for these screws. Preoperative computed tomographic (CT) scans of 1-mm slice thickness were obtained of the whole surgical area. The CT data were imported into a computer navigation system. We developed a 3-dimensional full-scale model of the patient's spine using a rapid prototyping technique from the CT data. Molds of the left and right sides at each vertebra were also constructed. One hole (2.0 mm in diameter and 2.0 cm in length) was made in each mold for the insertion of a screw guide. We performed a simulated surgery using the bone model and the mold before operation in all patients. The mold was firmly attached to the surface of the lamina and the guide wire was inserted using the intraoperative image of lateral vertebra. The proper insertion point, direction, and length of the guide were also confirmed both with the model bone and the image intensifier in the operative field. Then, drilling using a cannulated drill and tapping using a cannulated tapping device were carried out. Eleven consecutive patients who underwent posterior spinal fusion surgery using this technique since 2009 are included. The screw positions in the sagittal and axial planes were evaluated by postoperative CT scan to check for malpositioning. The screw insertion was done in the same manner as the simulated surgery. With the aid of this guide the pedicle screws and Magerl screws could be easily inserted even at the level where the pedicle seemed to be very thin and sclerotic on the CT scan. Postoperative CT scan showed that there were no critical breaches of the screws. This method employing the device using a 3-dimensional image guide seems to be easy and safe to use. The technique may improve the safety of pedicle screw and Magerl screw insertion even in difficult cases with narrow sclerotic pedicles.

New technique of skin embedded wire double-sided laser beam welding

NASA Astrophysics Data System (ADS)

Han, Bing; Tao, Wang; Chen, Yanbin

2017-06-01

In the aircraft industry, double-sided laser beam welding is an approved method for producing skin-stringer T-joints on aircraft fuselage panels. As for the welding of new generation aluminum-lithium alloys, however, this technique is limited because of high hot cracking susceptibility and strengthening elements' uneven distributions within weld. In the present study, a new technique of skin embedded wire double-sided laser beam welding (LBW) has been developed to fabricate T-joints consisting of 2.0 mm thick 2060-T8/2099-T83 aluminum-lithium alloys using eutectic alloy AA4047 filler wire. Necessary dimension parameters of the novel groove were reasonably designed for achieving crack-free welds. Comparisons were made between the new technique welded T-joint and conventional T-joint mainly on microstructure, hot crack, elements distribution features and mechanical properties within weld. Excellent crack-free microstructure, uniform distribution of silicon and superior tensile properties within weld were found in the new skin embedded wire double-sided LBW T-joints.

Percutaneous coronary angioplasty of a left anterior descending artery implanted on a Dacron coronary prosthesis on an aortic conduit.

PubMed

Drobinski, G; Thomas, D; Funck, F; Metzger, J P; Canny, M; Grosgogeat, Y

1986-08-01

Certain surgical techniques may make it difficult to catheterize the coronary ostia and perform percutaneous coronary angioplasty. We report the case of a 48 year old patient who developed unstable angina four years after a Bentall's procedure with reimplantation of the coronary arteries on a Dacron coronary prosthesis. The anginal pain was related to very severe stenosis of the proximal segment of the left anterior descending artery. The difficulties encountered during the dilatation procedure were due to: (a) the ectopic position of the ostium of the prosthesis on the anterior aortic wall; (b) the forces exerted on the aortic prosthesis wall and on the valvular prosthesis during positioning of the guiding catheter which were poorly tolerated and induced a vagal reaction; (c) the direction taken by the distal tip of the guiding catheter, perpendicular to the wall of the aortic prosthesis; (d) the sinuosity of the arterial trajectory: the left coronary segment of the coronary prosthesis was directed towards the left circumflex artery rather than towards the left anterior descending artery. Coronary angioplasty succeeded after relatively complex technical procedures: special guiding catheter, unusual intra-aortic manoeuvres for positioning the guiding catheter, dilatation catheter change on a 3-metre long guide wire in order to cross the stenotic segment; this was performed with a super low-profiled dilatation catheter. There were no complications and anginal pain disappeared.

Stiffness and frictional resistance of a superelastic nickel-titanium orthodontic wire with low-stress hysteresis.

PubMed

Liaw, Yu-Cheng; Su, Yu-Yu M; Lai, Yu-Lin; Lee, Shyh-Yuan

2007-05-01

Stress-induced martensite formation with stress hysteresis that changes the elasticity and stiffness of nickel-titanium (Ni-Ti) wire influences the sliding mechanics of archwire-guided tooth movement. This in-vitro study investigated the frictional behavior of an improved superelastic Ni-Ti wire with low-stress hysteresis. Improved superelastic Ni-Ti alloy wires (L & H Titan, Tomy International, Tokyo, Japan) with low-stress hysteresis were examined by using 3-point bending and frictional resistance tests with a universal test machine at a constant temperature of 35 degrees C, and compared with the former conventional austenitic-active superelastic Ni-Ti wires (Sentalloy, Tomy International). Wire stiffness levels were derived from differentiation of the polynomial regression of the unloading curves, and values for kinetic friction were measured at constant bending deflection distances of 0, 2, 3, and 4 mm, respectively. Compared with conventional Sentalloy wires, the L & H Titan wire had a narrower stress hysteresis including a lower loading plateau and a higher unloading plateau. In addition, L & H Titan wires were less stiff than the Sentalloy wires during most unloading stages. Values of friction measured at deflections of 0, 2, and 3 mm were significantly (P <.05) increased in both types of wire. However, they showed a significant decrease in friction from 3 to 4 mm of deflection. L & H Titan wires had less friction than Sentalloy wires at all bending deflections (P <.05). Stress-induced martensite formation significantly reduced the stiffness and thus could be beneficial to decrease the binding friction of superelastic Ni-Ti wires during sliding with large bending deflections. Austenitic-active alloy wires with low-stress hysteresis and lower stiffness and friction offer significant potential for further investigation.

Nickel-Titanium Wire as Suture Material: A New Technique for the Fixation of Skin.

PubMed

Li, Haidong; Song, Tao

2018-01-29

To introduce nickel-titanium wire as suture material for closure of incisions in cleft lip procedures. Closure of skin incisions using nickel-titanium wire as suture material, with postoperative follow-up wound evaluation. There was excellent patient satisfaction and good cosmetic outcome. Nickel-titanium wire is an excellent alternative for suture closure of cleft lip surgical incisions.

Method for making a hot wire anemometer and product thereof

NASA Technical Reports Server (NTRS)

Milkulla, V. (Inventor)

1977-01-01

A hot wire anemometer probe is described that includes a ceramic body supporting two conductive rods parallel to each other. The body has a narrow edge surface from which the rods protrude. A probe wire is welded to the rods and extends along the edge surface. A ceramic adhesive is used to secure the probe wire to the surface so that the probe wire is rigid. A method for fabricating the probe is also described in which the body is molded and precisely shaped by machining techniques before the probe wires are installed.

Add-On Shielding for Unshielded Wire

NASA Technical Reports Server (NTRS)

Koenig, J. C.; Billitti, J. W.; Tallon, J. M.

1983-01-01

Fabrication sequence used to produce compact shields slipped into place from free ends of wires already soldered into connectors at other ends. Single shields are formed into harnesses by connecting grounding jumpers. Technique is especially useful for small diameter wire attached to microminiature connectors.

Surface characteristics and damage distributions of diamond wire sawn wafers for silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sopori, Bhushan; Devayajanam, Srinivas; Basnyat, Prakash

2016-01-01

This paper describes surface characteristics, in terms of its morphology, roughness and near-surface damage of Si wafers cut by diamond wire sawing (DWS) of Si ingots under different cutting conditions. Diamond wire sawn Si wafers exhibit nearly-periodic surface features of different spatial wavelengths, which correspond to kinematics of various movements during wafering, such as ingot feed, wire reciprocation, and wire snap. The surface damage occurs in the form of frozen-in dislocations, phase changes, and microcracks. The in-depth damage was determined by conventional methods such as TEM, SEM and angle-polishing/defect-etching. However, because these methods only provide local information, we have alsomore » applied a new technique that determines average damage depth over a large area. This technique uses sequential measurement of the minority carrier lifetime after etching thin layers from the surfaces. The lateral spatial damage variations, which seem to be mainly related to wire reciprocation process, were observed by photoluminescence and minority carrier lifetime mapping. Our results show a strong correlation of damage depth on the diamond grit size and wire usage.« less

Guided Growth of Horizontal ZnSe Nanowires and their Integration into High-Performance Blue-UV Photodetectors.

PubMed

Oksenberg, Eitan; Popovitz-Biro, Ronit; Rechav, Katya; Joselevich, Ernesto

2015-07-15

Perfectly aligned horizontal ZnSe nano-wires are obtained by guided growth, and easily integrated into high-performance blue-UV photodetectors. Their crystal phase and crystallographic orientation are controlled by the epitaxial relations with six different sapphire planes. Guided growth paves the way for the large-scale integration of nanowires into optoelectronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with wire osteosynthesis: a comparative laser fluorescence and Raman spectral study on rabbits.

PubMed

Pinheiro, Antônio Luiz Barbosa; Santos, Nicole Ribeiro Silva; Oliveira, Priscila Chagas; Aciole, Gilberth Tadeu Santos; Ramos, Thais Andrade; Gonzalez, Tayná Assunção; da Silva, Laís Nogueira; Barbosa, Artur Felipe Santos; Silveira, Landulfo

2013-05-01

The aim of the present study was to assess, by Raman spectroscopy and laser fluorescence, the repair of surgical fractures fixed with wire osteosynthesis treated or not with infrared laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) =16 J/cm(2), ϕ=0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libitum. The fractures in groups II, III, IV, and V were fixed with wires. Animals in groups III and V were grafted with hydroxyapatite (HA) and guided bone regeneration (GBR) technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) =112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. The Raman results showed basal readings of 1,234.38 ± 220. Groups WO+B+L showed higher readings (1,680.22 ± 822) and group WO+B the lowest (501.425 ± 328). Fluorescence data showed basal readings of 5.83333 ± 0.7. Groups WO showed higher readings (6.91667 ± 0.9) and group WO+B+L the lowest (1.66667 ± 0.5). There were significant differences between groups on both cases (p<0.05). Pearson correlation was negative and significant (R (2)   = -0.60; p<0.001), and it was indicative that, when the Raman peaks of calcium hydroxyapatite (CHA) are increased, the level of fluorescence is reduced. It is concluded that the use of near-infrared lasertherapy associated to HA graft and GBR was effective in improving bone healing on fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy and decrease of the organic components as shown by the fluorescence readings.

Assembly techniques for ultra-low mass drift chambers

NASA Astrophysics Data System (ADS)

Assiro, R.; Cascella, M.; Grancagnolo, F.; L'Erario, A.; Miccoli, A.; Rella, S.; Spedicato, M.; Tassielli, G.

2014-03-01

We presents a novel technique for the fast assembly of next generation ultra low mass drift chambers offering space point resolution of the order of 100 μm and high tolerance to pile-up. The chamber design has been developed keeping in mind the requirements for the search of rare processes: high resolutions (order of 100-200 KeV/c) for particles momenta in a range (50-100 MeV/c) totally dominated by the multiple scattering contribution (e.g., muon and kaon decay experiment such as MEG at PSI and Mu2e and ORKA at Fermilab). We describe a novel wiring strategy enabling the semiautomatic wiring of a complete layer with a high degree of control over wire tension and position. We also present feed-through-less wire anchoring system. These techniques have been already implemented at INFN-Lecce in the construction of a prototype drift chamber to be soon tested with cosmic rays and particle beams.

The Fine Wire Technique for Flexor Tenolysis.

PubMed

Rosenblum, Matthew K; Baltodano, Pablo A; Weinberg, Maxene H; Whipple, Lauren A; Gemmiti, Amanda L; Whipple, Richard E

2017-11-01

Flexor tenolysis surgery for flexor digitorum profundus and superficialis adhesions is a common procedure performed by hand surgeons. Releasing these adhered tendons can greatly improve hand function and improve quality of life. Recent evidence, however, has shown that the outcomes of tenolysis surgeries are often suboptimal and can result in relapsing adhesions or even tendon ruptures. This article describes a new technique with potential for reduced complication rates: The Fine Wire Technique for Flexor Tenolysis (FWT). Following FWT, the patient detailed in this article had an excellent recovery of function and no complications: including tendon rupture, infection, hematomas, or any other complications. She reported a major improvement from her preoperative functionality and continues to have this level of success. The wire's thinness allows for a swift tenolysis. The FWT is a new option available to the hand surgeon associated with good functional results. The wire is readily available to the clinician and is also inexpensive.

Production of small diameter high-temperature-strength refractory metal wires

NASA Technical Reports Server (NTRS)

Petrasek, D. W.; Signorelli, R. A.; King, G. W.

1973-01-01

Special thermomechanical techniques (schedules) have been developed to produce small diameter wire from three refractory metal alloys: colombian base alloy, tantalum base alloy, and tungsten base alloy. High strengths of these wires indicate their potential for contributing increased strength to metallic composites.

Intrasystem Analysis Program (IAP) Structural Design Study.

DTIC Science & Technology

1981-06-01

accuracy constraints, and user competence . This report is designed to serve as a guide in con- structing procedures and identifying those aspects of the...parameters. 3.3.3 Userability The term "Userability" refers here to the level of competence assumed for an IAP analyst in need of a procedure. There...media the wires pass through is homogeneous along the length of the wires. Under these assumptions the wave propagation is predominantly tranverse

Defense Science Board Summer Study on Autonomy

DTIC Science & Technology

2016-06-01

hours, at a maximum velocity of 40 mph, with a maximum payload of 9 kg (20 lbs); a maximum range of 160 km (100 miles); and can operate in wind /gust...existing mine disposal platform, such as Seafox, with contact reacquisition and neutralization capability. Seafox is a wire -guided mine neutralizer...functions, will retain operator control of neutralization and will remove the need for personnel to enter the minefield to execute fly- by- wire

[Gastro-entero anastomosis with flexible endoscope with the help of rare-earth magnets on biosynthetic model made of the gastrointestinal tract of slaughtered pigs].

PubMed

Lukovich, Péter; Jónás, Attila; Bata, Pál; Tari, Krisztina; Váradi, Gábor; Kádár, Balázs; Mehdi, Sadat Akhavi; Kupcsulik, Péter

2007-04-01

Gastro-entero anastomosis with flexible endoscope with the help of rare-earth magnets on biosynthetic model made of the gastrointestinal tract of slaughtered pigs Numerous malignant diseases may cause gastric outlet obstruction. The surgical gastrointestinal bypass, besides the fact that it requires narcosis, is also associated with high risks for patients with poor general condition. Endoscopic insertion of self-expandable metal stent is less invasive, but often causes complications. In the last years some studies examined a new minimal invasive technique, in which magnets are used to create gastroenteric anastomosis. A biosynthetic model was developed from combined synthetic materials with biogenic specimens taken from slaughtered domestic pigs. The procedure was performed with endoscopic and fluoroscopic guidance. To increase X-ray contrast differences the model was put into physiological saline solution. Two rare-earth magnets (Br: 2500 Gauss, D: 10 mm) with central hole were inserted with the help of a guiding wire and duodenal probe. The first magnet was placed in the first jejunal loop; the second one was placed in the stomach. The gastric magnet was maneuvered using the endoscope. When the magnets reached the right position, the guiding wires were removed to let the magnets stick together. The pressure between the magnets will result in a sterile inflammation on the living tissue which develops adhesion between the bowels, and 7-10 days later anastomosis will develop as a result of the necrosis. The biosynthetic model could be used for training endoscopy without sacrificing animals. In the end of the procedure the magnets stuck together across gastric and jejunal walls in all ten cases successfully. By practice the period necessary for the procedure could be decreased from 40 to 20 minutes. The technique could be made with standard upper endoscope and instruments, and after practice on living animals it could potentially be a useful solution for complaints of gastric outlet obstruction.

Hot-wire Laser Welding of Deep and Wide Gaps

NASA Astrophysics Data System (ADS)

Näsström, J.; Frostevarg, J.; Silver, T.

Heavy section Gas Metal Arc Welding (GMAW) usually requires special edge preparation and several passes. One alternative for increased performance is Laser Arc Hybrid Welding (LAHW). For very thick sheets however, imperfections like root drops or solidification cracks can occur. In this study, other techniques are also studied, including multi-pass filling of deep gaps with wire deposition. A laser is then used to melt the filler and base material. The hot- and cold wire laser welding processes are highly sensitive to wire-laser positioning, where controlled melting of the wire is essential. Apart from a comprehensive literature survey, preliminary experiments were also performed in order to find a novel method variant that can successfully fill deep and wide gaps. The method applied uses a defocused laser that generates the melt pool. A resistance heated wire is fed into the melt pool front in a leading position. This is similar to additive manufacturing techniques such as laser direct metal deposition with wire. A layer height of several millimeters can be achieved and rather low laser power can be chosen. The preliminary experiments were observed using high speed imaging and briefly evaluated by visual examination of the resulting beads. Using a defocused laser beam turned out to have two major advantages; 1. It adds heat to the melt pool in a manner that properly fuses the bottom and walls of the base material. 2. It counteracts difficulties due to an irregularly oscillating filler wire. These early results show that this can be a promising technique for joining thick steels with wide gaps.

How should I treat a patient to remove a fractured jailed side branch wire?

PubMed

Owens, Colum G; Spence, Mark S

2011-08-01

A 53-year-old female was sent for diagnostic angiography after successful reperfusion therapy for an anterior ST-elevation myocardial infarct. The culprit lesion was a LAD/D1 bifurcation stenosis. Coronary angiography, intravascular ultrasound. Left anterior descending artery/first diagonal artery bifurcation stenosis, fractured jailed side branch wire. Provisional stenting strategy for bifurcation stenosis. Consideration of surgical and percutaneous options to retrieve fractured, jailed, side branch wire. Wire and balloon catheter wrap technique for retrieval of fractured wire.

A Method For The Verification Of Wire Crimp Compression Using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. E.; Perey, Daniel F.; Yost, William t.

2010-01-01

The development of a new ultrasonic measurement technique to assess quantitatively wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. To demonstrate the technique, the case of incomplete compression of crimped connections is ultrasonically tested, and the results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently predicts good crimps when the ultrasonic transmission is above a certain threshold amplitude level. A quantitative measure of the quality of the crimped connection based on the ultrasonic energy transmitted is shown to respond accurately to crimp quality. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. A comparison of the results of two different instruments is presented and shows reproducibility between instruments within a 95% confidence bound.

UHMWPE Sublaminar Wires in Posterior Spinal Instrumentation: Stability and Biocompatibility Assessment in an Ovine Pilot Study.

PubMed

Bogie, Rob; Voss, Laura; Arts, Jacobus J; Lataster, Arno; Willems, Paul C; Brans, Boudewijn; van Rhijn, Lodewijk W; Welting, Tim J M

2016-12-01

An animal study. To explore ultra-high molecular weight polyethylene (UHMWPE) sublaminar wires in spinal surgery and to assess stability and biocompatibility of the UHMWPE instrumentation in an ovine model. Sublaminar wiring is a well-established technique in segmental scoliosis surgery. However, during introduction and/or removal of the metal sublaminar wires, neurological problems can occur. Abrasion after cutting metal wires for removal can lead to damage to the dural sac. Sublaminar wires have to withhold large forces and breakage of the wires can occur. Different types of sublaminar wires have been developed to address these problems. UHMWPE sublaminar wires can potentially substitute currently used metal sublaminar metal wires. In vivo testing and biocompatibility analysis of UHMWPE wires are recommended before clinical use in spinal surgery. In 6 immature sheep, pedicle screws were instrumented at lumbar level L4 and attached with titanium rods to 4 thoracolumbar vertebrae using 3- and 5-mm-wide UHMWPE sublaminar wiring constructions in 5 animals. Titanium sublaminar wires were applied in 1 animal to function as a control subject. After a follow-up period of 16 weeks, the animals were sacrificed and the spines were isolated. Radiographs and computed tomography (CT) scans were made to assess stability of the instrumentation. The vertebrae were dissected for macroscopic and histologic evaluation. None of the wires had loosened and the instrumentation remained stable. CT scans and radiographs showed no signs of failure of the instrumentation and no neurological complications occurred. Although several bony bridges were seen on CT, growth was observed at the operated levels. Biocompatibility was assessed by macroscopical and histologic analysis, showing no signs of dural or epidural inflammation. This pilot animal study shows that UHMWPE sublaminar wiring is a safe technique. The UHMWPE wires are biocompatible and provide sufficient stability in spinal instrumentation. Heterotopic ossification because of periost reactions in the ovine spine led to some restrictions in this study.

The construction technique of the high granularity and high transparency drift chamber of MEG II

NASA Astrophysics Data System (ADS)

Chiarello, G.; Chiri, C.; Corvaglia, A.; Grancagnolo, F.; Miccoli, A.; Panareo, M.; Pinto, C.; Spedicato, M.; Tassielli, G. F.

2017-07-01

The MEG experiment searches for the charged lepton flavor violating decay, μ +→ e+γ. MEG has already determined the world best upper limit on the branching ratio BR<4.2× 10-13 at 90% CL. An upgrade of the whole detector has been approved to obtain a substantial increase in sensitivity. Currently MEG is in upgrade phases, this phase involves all the detectors. The new positron tracker is a single volume, full stereo, small cells drift chamber (DCH) co-axial to the beam line. It is composed of 10 concentric layers and each single drift cell is approximately square 7 mm side, with a 20 μ m gold plated W sense wire surrounded by 40 μ m and 50 μ m silver plated Al field wires in a ratio of 5:1, about 12,000 wires. Due to the high wire density (12 wires/cm2), the use of the classical feed-through technique as wire anchoring system could hardly be implemented and therefore it was necessary to develop new wiring strategies. The number of wires and the stringent requirements on the precision of their position and on the uniformity of the wire mechanical tension impose the use of an automatic system to operate the wiring procedures. This wiring robot, designed and built at the INFN Lecce and University of Salento laboratories, consists of: ṡ a semiautomatic wiring machine with a high precision on wire mechanical tensioning (better than 0.5 g) and on wire positioning (20 μ m) for simultaneous wiring of multiwire layers; ṡ a contact-less infrared laser soldering tool; ṡ an automatic handling system for storing and transporting the multi-wire layers. The drift chamber is currently under construction at INFN and should be completed by the end of summer 2017 to be then delivered to PSI for commissioning.

Transverse vorticity measurements using an array of four hot-wire probes

NASA Technical Reports Server (NTRS)

Foss, J. F.; Klewickc, C. L.; Disimile, P. J.

1986-01-01

A comprehensive description of the technique used to obtain a time series of the quasi-instantaneous transverse vorticity from a four wire array of probes is presented. The algorithmic structure which supports the technique is described in detail and demonstration data, from a large plane shear layer, are presented to provide a specific utilization of the technique. Sensitivity calculations are provided which allow one contribution to the inherent uncertainty of the technique to be evaluated.

Anatomic Assessment of K-Wire Trajectory for Transverse Percutaneous Fixation of Small Finger Metacarpal Fractures: A Cadaveric Study.

PubMed

Grandizio, Louis C; Speeckaert, Amy; Kozick, Zach; Klena, Joel C

2018-01-01

The purpose of this cadaveric study is to evaluate the trajectory of percutaneous transverse Kirschner wire (K-wire) placement for fifth metacarpal fractures relative to the sagittal profile of the fifth metacarpal in order to develop a targeting strategy for the treatment of fifth metacarpal fractures. Using 12 unmatched fresh human upper limbs, we evaluated the trajectory of percutaneous transverse K-wire placement relative to the sagittal profile of the fifth metacarpal in order to develop a targeting strategy for treatment of fifth metacarpal fractures. The midpoint of the small and ring finger metacarpals in the sagittal plane was identified at 3 points. At each point, a K-wire was inserted from the small finger metacarpal into the midpoint of the ring finger metacarpal ("center-center" position). The angle of the transverse K-wire relative to the table needed to achieve a center-center position averaged 20.8°, 18.9°, and 16.7° for the proximal diaphysis, middiaphysis, and the collateral recess, respectively. Approximately 80% of transversely placed K-wires obtained purchase in the long finger metacarpal. These results can serve as a guide to help surgeons in the accurate placement of percutaneous K-wires for small finger metacarpal fractures and may aid in surgeon training.

Importance of Adjunct Delivery Techniques to Optimize Deployment Success of Distal Protection Filters During Vein Graft Intervention.

PubMed

Kaliyadan, Antony G; Chawla, Harnish; Fischman, David L; Ruggiero, Nicholas; Gannon, Michael; Walinsky, Paul; Savage, Michael P

2017-02-01

This study assessed the impact of adjunct delivery techniques on the deployment success of distal protection filters in saphenous vein grafts (SVGs). Despite their proven clinical benefit, distal protection devices are underutilized in SVG interventions. Deployment of distal protection filters can be technically challenging in the presence of complex anatomy. Techniques that facilitate the delivery success of these devices could potentially improve clinical outcomes and promote greater use of distal protection. Outcomes of 105 consecutive SVG interventions with attempted use of a FilterWire distal protection device (Boston Scientific) were reviewed. In patients in whom filter delivery initially failed, the success of attempted redeployment using adjunct delivery techniques was assessed. Two strategies were utilized sequentially: (1) a 0.014" moderate-stiffness hydrophilic guidewire was placed first to function as a parallel buddy wire to support subsequent FilterWire crossing; and (2) if the buddy-wire approach failed, predilation with a 2.0 mm balloon at low pressure was performed followed by reattempted filter delivery. The study population consisted of 80 men and 25 women aged 73 ± 10 years. Mean SVG age was 14 ± 6 years. Complex disease (American College of Cardiology/American Heart Association class B2 or C) was present in 92%. Initial delivery of the FilterWire was successful in 82/105 patients (78.1%). Of the 23 patients with initial failed delivery, 8 (35%) had successful deployment with a buddy wire alone, 7 (30%) had successful deployment with balloon predilation plus buddy wire, 4 (17%) had failed reattempt at deployment despite adjunct maneuvers, and in 4 (17%) no additional attempts at deployment were made at the operator's discretion. Deployment failure was reduced from 21.9% initially to 7.6% after use of adjunct delivery techniques (P<.01). No adverse events were observed with these measures. Deployment of distal protection devices can be technically difficult with complex SVG disease. Adjunct delivery techniques are important to optimize deployment success of distal protection filters during SVG intervention.

Terahertz generation from laser-driven ultrafast current propagation along a wire target

NASA Astrophysics Data System (ADS)

Zhuo, H. B.; Zhang, S. J.; Li, X. H.; Zhou, H. Y.; Li, X. Z.; Zou, D. B.; Yu, M. Y.; Wu, H. C.; Sheng, Z. M.; Zhou, C. T.

2017-01-01

Generation of intense coherent THz radiation by obliquely incidenting an intense laser pulse on a wire target is studied using particle-in-cell simulation. The laser-accelerated fast electrons are confined and guided along the surface of the wire, which then acts like a current-carrying line antenna and under appropriate conditions can emit electromagnetic radiation in the THz regime. For a driving laser intensity ˜3 ×1018W /cm2 and pulse duration ˜10 fs, a transient current above 10 KA is produced on the wire surface. The emission-cone angle of the resulting ˜0.15 mJ (˜58 GV/m peak electric field) THz radiation is ˜30∘ . The conversion efficiency of laser-to-THz energy is ˜0.75 % . A simple analytical model that well reproduces the simulated result is presented.

Measurement and Modeling of Dispersive Pulse Propagation in Drawn Wire Waveguides

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Kohl, Thomas W.; Rogers, Wayne P.

1995-01-01

An analytical model of dispersive pulse propagation in semi-infinite cylinders due to transient axially symmetric end conditions has been experimentally investigated. Specifically, the dispersive propagation of the first axially symmetric longitudinal mode in thin wire waveguides, which have ends in butt contact with longitudinal piezoelectric ultrasonic transducers, is examined. The method allows for prediction of a propagated waveform given a measured source waveform, together with the material properties of the cylinder. Alternatively, the source waveform can be extracted from measurement of the propagated waveform. The material properties required for implementation of the pulse propagation model are determined using guided wave phase velocity measurements. Hard tempered aluminum 1100 and 304 stainless steel wires, with 127, 305, and 406 micron diam., were examined. In general, the drawn wires were found to behave as transversely isotropic media.

Measurement and modeling of dispersive pulse propagation in draw wire waveguides

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Kohl, Thomas W.; Rogers, Wayne P.

1995-01-01

An analytical model of dispersive pulse propagation in semi-infinite cylinders due to transient axially symmetric end conditions has been experimentally investigated. Specifically, the dispersive propagation of the first axially symmetric longitudinal mode in thin wire waveguides, which have ends in butt contact with longitudinal piezoelectric ultrasonic transducers, is examined. The method allows for prediction of a propagated waveform given a measured source waveform, together with the material properties of the cylinder. Alternatively, the source waveform can be extracted from measurement of the propagated waveform. The material properties required for implementation of the pulse propagation model are determined using guided wave phase velocity measurements. Hard tempered aluminum 1100 and 304 stainless steel wires, with 127, 305, and 406 micron diam., were examined. In general, the drawn wires were found to behave as transversely isotropic media.

Computed Tomography-Guided Methylene Blue Labeling Prior to Thoracoscopic Resection of Small Deeply Placed Pulmonary Nodules. Do We Really Need Palpation?

PubMed

Findik, Gokturk; Demiröz, S Mustafa; Apaydın, Selma Mine Kara; Ertürk, Hakan; Biri, Suzan; Incekara, Funda; Aydogdu, Koray; Kaya, Sadi

2017-08-01

Background  Video-assisted thoracic surgery (VATS) is widely used for thoracic surgery operations, and day by day it becomes routine for the excision of undetermined pulmonary nodules. However, it is sometimes hard to reach millimetric nodules through a VATS incision. Therefore, some additional techniques were developed to reach such nodules little in size and which are settled on a challenging localization. In the literature, coils, hook wires, methylene blue, lipidol, and barium staining, and also ultrasound guidance were described for this aim. Herein we discuss our experience with CT-guided methylene blue labeling of small, deeply located pulmonary nodules just before VATS excision. Method  From April 2013 to October 2016, 11 patients with millimetric pulmonary nodules (average 8, 7 mm) were evaluated in our clinic. For all these patients who had strong predisposing factors for malignancy, an 18F-FDG PET-CT scan was also performed. The patients whose nodules were decided to be excised were consulted the radiology clinic. The favorable patients were taken to CT room 2 hours prior to the operation, and CT-guided methylene blue staining were performed under sterile conditions. Results  Mean nodule size of 11 patients was 8.7 mm (6, 2-12). Mean distance from the visceral pleural surface was 12.7 mm (4-29.3). Four of the nodules were located on the left (2 upper lobes, 2 lower lobes), and seven of them were on the right (four lower lobes, two upper lobes, one middle lobe). The maximum standardized uptake values (SUV max) on 18F-FDG PET/CT scan ranged between 0 and 2, 79. Conclusion  CT-guided methylene blue staining of millimetric deeply located pulmonary nodules is a safe and feasible technique that helps surgeon find these undetermined nodules by VATS technique without any need of digital palpation. Georg Thieme Verlag KG Stuttgart · New York.

Reducing Magnetic Fields Around Power Cables

NASA Technical Reports Server (NTRS)

Sargent, Noel B.; Gitelman, Florida; Pongracz-Bartha, Edward; Spalding, John

1993-01-01

Four power conductors arranged symmetrically about fifth grounded conductor. Four current-carrying wires arranged symmetrically around central grounded wire that nominally carries no current. In comparison with other cable configurations, this one results in smaller magnetic fields around cable. Technique for use when size of wires in cable makes twisting impractical.

Wrapped Wire Detects Rupture Of Pressure Vessel

NASA Technical Reports Server (NTRS)

Hunt, James B.

1990-01-01

Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

Distal left circumflex coronary artery flow reserve recorded by transthoracic Doppler echocardiography: a comparison with Doppler-wire

PubMed Central

Auriti, Antonio; Pristipino, Christian; Cianfrocca, Cinzia; Granatelli, Antonino; Guido, Vincenzo; Pelliccia, Francesco; Greco, Salvatore; Richichi, Giuseppe; Santini, Massimo

2007-01-01

Background Coronary flow reserve (CFR) recording by means of transthoracic echocardiography (TTDE) in all the main distal coronary arteries is a challenge for advanced echocardiography. Validation studies of TTDE versus Doppler-wire (DW) recordings are available for Left Anterior Descending artery (LAD) and the Posterior Descending coronary artery (PD), but lacking for the more technically challenging Left Circumflex coronary artery (LCx). Aim To evaluate the reliability of TTDE in assessing CFR in LCx when compared to the intracoronary Doppler flow-wire gold standard. Methods we evaluated 5 patients (age = 60 ± 9 years, 5 males) on LCx by TTDE and invasive CFR assessment. TTDE recording was performed using a low-frequency probe, with a four-chamber as a guiding 2D view. The 2 tests were performed on different days and in random order within 48 hours in a blind fashion. Vasodilator stimulus was adenosine, intravenously (140 γ/kg/min × 3–6 min) for TTDE and intracoronary (40 γ bolus) for DW recordings. Results CFR values on LCx ranged from 1.9 to 2.8 for DW, and from 2.0 to 3.0 for TTDE, with an overall correlation of R = 0,85 (p = 0,06); normal (CFR > 2.5) or abnormal (CFR < 2.5) value was concordantly identified by the 2 techniques in 4 out 5 cases (80%). Conclusion CFR of LCx artery can be obtained noninvasively with TTDE. PMID:17572907

Successful rotational atherectomy over RG3 guidewire after failure of various techniques to deliver RotaWire.

PubMed

Kaneko, Umihiko; Kashima, Yoshifumi; Kanno, Daitaro; Sugie, Takuro; Kobayashi, Ken; Fujita, Tsutomu

2017-10-01

Although performing rotational atherectomy (RA) requires guidewire exchange for the dedicated guidewire, RotaWire guidewire (Boston Scientific) exhibits much lower performance than conventional guidewire. Consequently, there are times when RotaWire cannot be advanced past the lesion independently or using a microcatheter exchange technique, rendering RA impossible. We present a case of a heavily calcified, device-uncrossable, and non-expansible chronic total occlusion lesion successfully revascularized with RA over RG3 guidewire (Asahi Intecc), which has a length of 330 cm, hydrophilic coating, and a 0.010-inch-long shaft. RG3 provided excellent cross-ability and RA could also be performed over RG3 without guidewire exchange for the RotaWire.

The influence of bracket design on frictional losses in the bracket/arch wire system.

PubMed

Schumacher, H A; Bourauel, C; Drescher, D

1999-01-01

In arch guided tooth movement, the essential role played by bracket configuration with respect to sliding friction has been recognized by the manufacturers, a fact which has had an increasing impact on the design and marketing of new bracket models in recent years. The aim of the present in-vitro study was to investigate the influence of different bracket designs on sliding mechanics. Five differently shaped stainless steel brackets (Discovery: Dentaurum, Damon SL: A-Company, Synergy: Rocky Mountain Orthodontics, Viazis bracket and Omni Arch appliance: GAC) were compared in the 0.022"-slot system. The Orthodontic Measurement and Simulation System (OMSS) was used to quantify the difference between applied force (NiTi coil spring, 1.0 N) and orthodontically effective force and to determine leveling losses occurring during the sliding process in arch guided tooth movement. Simulated canine retraction was performed using continuous arch wires with the dimensions 0.019" x 0.025" (Standard Steel, Unitek) and 0.020" x 0.020" (Ideal Gold, GAC). Comparison of the brackets revealed friction-induced losses ranging from 20 to 70%, with clear-cut advantages resulting from the newly developed bracket types. However, an increased tendency towards leveling losses in terms of distal rotation (maximum 15 degrees) or buccal root torque (maximum 20 degrees) was recorded, especially with those brackets giving the arch wire increased mobility due to their shaping or lack of ligature wire.

Progressive migration of broken Kirschner wire into the proximal tibia following tension-band wiring technique of a patellar fracture--case report.

PubMed

Konda, Sanjit R; Dayan, Alan; Egol, Kenneth A

2012-01-01

Wire breakage and migration is a known complication of using a wire tension band construct to treat displaced patella fractures. We report a case of a broken K-wire that migrated from the patella completely into the proximal tibia without complication 9 years after the index surgery. This report highlights the fact that wire migration can occur long after fracture healing and be relatively asymptomatic. But because the complications of wire migration can be deadly, it requires diligence on the part of the physician to educate the patient that new knee pain after operative fixation requires formal evaluation by the treating surgeon.

A novel fenestration technique for abdominal aortic dissection membranes using a combination of a needle re-entry catheter and the "cheese-wire" technique.

PubMed

Kos, Sebastian; Gürke, Lorenz; Jacob, Augustinus L

2011-12-01

This study was designed to demonstrate the applicability of a combined needle-based re-entry catheter and "cheese-wire" technique for fenestration of abdominal aortic dissection membranes. Four male patients (mean age: 65 years) with acute complicated aortic type B dissections were treated at our institution by fenestrating the abdominal aortic dissection membrane using a hybrid technique. This technique combined an initial membrane puncture with a needle-based re-entry catheter using a transfemoral approach. A guidewire was passed through the re-entry catheter and across the membrane. Using a contralateral transfemoral access, this guidewire was then snared, creating a through-and-through wire access. The membrane was then fenestrated using the cheese-wire maneuver. We successfully performed: (a) membrane puncture; (b) guidewire passage; (c) guidewire snaring; and (d) cheese-wire maneuver in all four cases. After this maneuver, decompression of the false lumen and acceptable arterial inflow into the true lumen was observed in all cases. The dependent visceral arteries were reperfused. In one case, portions of the fenestrated membrane occluded the common iliac artery, which was immediately and successfully stented. In another case, long-standing intestinal hypoperfusion before the fenestration resulted in reperfusion-related shock and intraoperative death of the patient. The described hybrid approach for fenestration of dissection membranes is technically feasible and may be established as a therapeutic method in cases with a complicated type B dissection.

Silane and Germane Molecular Electronics.

PubMed

Su, Timothy A; Li, Haixing; Klausen, Rebekka S; Kim, Nathaniel T; Neupane, Madhav; Leighton, James L; Steigerwald, Michael L; Venkataraman, Latha; Nuckolls, Colin

2017-04-18

This Account provides an overview of our recent efforts to uncover the fundamental charge transport properties of Si-Si and Ge-Ge single bonds and introduce useful functions into group 14 molecular wires. We utilize the tools of chemical synthesis and a scanning tunneling microscopy-based break-junction technique to study the mechanism of charge transport in these molecular systems. We evaluated the fundamental ability of silicon, germanium, and carbon molecular wires to transport charge by comparing conductances within families of well-defined structures, the members of which differ only in the number of Si (or Ge or C) atoms in the wire. For each family, this procedure yielded a length-dependent conductance decay parameter, β. Comparison of the different β values demonstrates that Si-Si and Ge-Ge σ bonds are more conductive than the analogous C-C σ bonds. These molecular trends mirror what is seen in the bulk. The conductance decay of Si and Ge-based wires is similar in magnitude to those from π-based molecular wires such as paraphenylenes However, the chemistry of the linkers that attach the molecular wires to the electrodes has a large influence on the resulting β value. For example, Si- and Ge-based wires of many different lengths connected with a methyl-thiomethyl linker give β values of 0.36-0.39 Å -1 , whereas Si- and Ge-based wires connected with aryl-thiomethyl groups give drastically different β values for short and long wires. This observation inspired us to study molecular wires that are composed of both π- and σ-orbitals. The sequence and composition of group 14 atoms in the σ chain modulates the electronic coupling between the π end-groups and dictates the molecular conductance. The conductance behavior originates from the coupling between the subunits, which can be understood by considering periodic trends such as bond length, polarizability, and bond polarity. We found that the same periodic trends determine the electric field-induced breakdown properties of individual Si-Si, Ge-Ge, Si-O, Si-C, and C-C bonds. Building from these studies, we have prepared a system that has two different, alternative conductance pathways. In this wire, we can intentionally break a labile, strained silicon-silicon bond and thereby shunt the current through the secondary conduction pathway. This type of in situ bond-rupture provides a new tool to study single molecule reactions that are induced by electric fields. Moreover, these studies provide guidance for designing dielectric materials as well as molecular devices that require stability under high voltage bias. The fundamental studies on the structure/function relationships of the molecular wires have guided the design of new functional systems based on the Si- and Ge-based wires. For example, we exploited the principle of strain-induced Lewis acidity from reaction chemistry to design a single molecule switch that can be controllably switched between two conductive states by varying the distance between the tip and substrate electrodes. We found that the strain intrinsic to the disilaacenaphthene scaffold also creates two state conductance switching. Finally, we demonstrate the first example of a stereoelectronic conductance switch, and we demonstrate that the switching relies crucially on the electronic delocalization in Si-Si and Ge-Ge wire backbones. These studies illustrate the untapped potential in using Si- and Ge-based wires to design and control charge transport at the nanoscale and to allow quantum mechanics to be used as a tool to design ultraminiaturized switches.

Electromagnetic Navigational Bronchoscopy Reduces the Time Required for Localization and Resection of Lung Nodules.

PubMed

Bolton, William David; Cochran, Thomas; Ben-Or, Sharon; Stephenson, James E; Ellis, William; Hale, Allyson L; Binks, Andrew P

The aims of the study were to evaluate electromagnetic navigational bronchoscopy (ENB) and computed tomography-guided placement as localization techniques for minimally invasive resection of small pulmonary nodules and determine whether electromagnetic navigational bronchoscopy is a safer and more effective method than computed tomography-guided localization. We performed a retrospective review of our thoracic surgery database to identify patients who underwent minimally invasive resection for a pulmonary mass and used either electromagnetic navigational bronchoscopy or computed tomography-guided localization techniques between July 2011 and May 2015. Three hundred eighty-three patients had a minimally invasive resection during our study period, 117 of whom underwent electromagnetic navigational bronchoscopy or computed tomography localization (electromagnetic navigational bronchoscopy = 81; computed tomography = 36). There was no significant difference between computed tomography and electromagnetic navigational bronchoscopy patient groups with regard to age, sex, race, pathology, nodule size, or location. Both computed tomography and electromagnetic navigational bronchoscopy were 100% successful at localizing the mass, and there was no difference in the type of definitive surgical resection (wedge, segmentectomy, or lobectomy) (P = 0.320). Postoperative complications occurred in 36% of all patients, but there were no complications related to the localization procedures. In terms of localization time and surgical time, there was no difference between groups. However, the down/wait time between localization and resection was significant (computed tomography = 189 minutes; electromagnetic navigational bronchoscopy = 27 minutes); this explains why the difference in total time (sum of localization, down, and surgery) was significant (P < 0.001). We found electromagnetic navigational bronchoscopy to be as safe and effective as computed tomography-guided wire placement and to provide a significantly decreased down time between localization and surgical resection.

Fiber-Drawn Metamaterial for THz Waveguiding and Imaging

NASA Astrophysics Data System (ADS)

Atakaramians, Shaghik; Stefani, Alessio; Li, Haisu; Habib, Md. Samiul; Hayashi, Juliano Grigoleto; Tuniz, Alessandro; Tang, Xiaoli; Anthony, Jessienta; Lwin, Richard; Argyros, Alexander; Fleming, Simon C.; Kuhlmey, Boris T.

2017-09-01

In this paper, we review the work of our group in fabricating metamaterials for terahertz (THz) applications by fiber drawing. We discuss the fabrication technique and the structures that can be obtained before focusing on two particular applications of terahertz metamaterials, i.e., waveguiding and sub-diffraction imaging. We show the experimental demonstration of THz radiation guidance through hollow core waveguides with metamaterial cladding, where substantial improvements were realized compared to conventional hollow core waveguides, such as reduction of size, greater flexibility, increased single-mode operating regime, and guiding due to magnetic and electric resonances. We also report recent and new experimental work on near- and far-field THz imaging using wire array metamaterials that are capable of resolving features as small as λ/28.

Factors affecting the outcomes of modified tension band wiring techniques in transverse patellar fractures.

PubMed

Hsu, Kai-Lan; Chang, Wei-Lun; Yang, Chyun-Yu; Yeh, Ming-Long; Chang, Chih-Wei

2017-12-01

Modified tension band wiring has been widely used to treat transverse patellar fractures. However, few studies have evaluated the clinical outcomes using different methods of Kirschner wire bending, location of the tension band, and depths of Kirschner wires. Thus, we tried to clarify these factors according to our clinical outcomes. This retrospective cohort study recruited consecutive patients underwent surgical fixation for patellar fractures using modified tension band technique between January 2010 and December 2015. Different factors in this procedure, including the bending manner of the Kirschner wires, their depth, and location of the tension band with respect to the superior and inferior border of the patella were recorded and analysed. The primary outcome was early loss of fixation. The secondary outcomes were minor loss of reduction, implant breakage, deep infection, and the need for implant removal. This study included 170 patients with patellar fractures. Regarding the bending method, similar results were obtained with bilaterally or proximally bent Kirschner wires. Regarding length, the tension band was placed closely (within 25% of the patella length) in 124 patients and distantly in 46 patients. The rates of loss of reduction and implant breakage were significantly higher in the distantly placed tension bands. Regarding depth, 37 patellar fractures were fixed with the Kirschner wires at the superficial one third of the patellae while the K- wires at the middle layer of patella were used in the remaining 133 patellar fractures. A significantly higher rate of minor loss of reduction was obtained using the superficial Kirschner wires. The modified tension band technique for transverse patella fractures provides favourable clinical outcomes, with low failure (5%) and infection (2%) rates. Implant irritation is the major complication, and almost half of cases require implant removal. The location of the tension band with respect to the superior and inferior border of the patella plays an important role in clinical outcomes. Placing the wire close to the patella may prevent major loss of reduction and implant breakage. Superficially placed Kirschner wires also affect clinical outcomes by increasing the rate of minor loss of reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrostatic wire for stabilizing a charged particle beam

DOEpatents

Prono, Daniel S.; Caporaso, George J.; Briggs, Richard J.

1985-01-01

In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

Electrostatic wire stabilizing a charged particle beam

DOEpatents

Prono, D.S.; Caporaso, G.J.; Briggs, R.J.

1983-03-21

In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

CT-Guided Superior Vena Cava Puncture: A Solution to Re-Establishing Access in Haemodialysis-Related Central Venous Occlusion Refractory to Conventional Endovascular Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalifa, Mohamed, E-mail: mkhalifa@nhs.net; Patel, Neeral R., E-mail: neeral.patel06@gmail.com; Moser, Steven, E-mail: steven.moser@imperial.nhs.uk

PurposeThe purpose of this technical note is to demonstrate the novel use of CT-guided superior vena cava (SVC) puncture and subsequent tunnelled haemodialysis (HD) line placement in end-stage renal failure (ESRF) patients with central venous obstruction refractory to conventional percutaneous venoplasty (PTV) and wire transgression, thereby allowing resumption of HD.MethodsThree successive ESRF patients underwent CT-guided SVC puncture with subsequent tract recanalisation. Ultrasound-guided puncture of the right internal jugular vein was performed, the needle advanced to the patent SVC under CT guidance, with subsequent insertion of a stabilisation guidewire. Following appropriate tract angioplasty, twin-tunnelled HD catheters were inserted and HD resumed.ResultsNomore » immediate complications were identified. There was resumption of HD in all three patients with a 100 % success rate. One patient’s HD catheter remained in use for 2 years post-procedure, and another remains functional 1 year to the present day. One patient died 2 weeks after the procedure due to pancreatitis-related abdominal sepsis unrelated to the Tesio lines.ConclusionCT-guided SVC puncture and tunnelled HD line insertion in HD-related central venous occlusion (CVO) refractory to conventional recanalisation options can be performed safely, requires no extra equipment and lies within the skill set and resources of most interventional radiology departments involved in the management of HD patients.« less

Random vibration (stress screening) of printed wiring assemblies

NASA Technical Reports Server (NTRS)

Bastien, Gilbert J.

1988-01-01

The results of a random vibration test screening (RVSS) study of the determination of the upper and lower vibration limits on printed wiring assemblies (PWA) are summarized. The study results are intended to serve as a guide for engineers and designers who make decisions on PWA features that need to withstand the stresses of dynamic testing and screening. The maximum allowable PWA deflection, G levels, and PSD levels are compared to the expected or actual levels to determine if deleterious effects will occur.

Integrating the Gradient of the Thin Wire Kernel

NASA Technical Reports Server (NTRS)

Champagne, Nathan J.; Wilton, Donald R.

2008-01-01

A formulation for integrating the gradient of the thin wire kernel is presented. This approach employs a new expression for the gradient of the thin wire kernel derived from a recent technique for numerically evaluating the exact thin wire kernel. This approach should provide essentially arbitrary accuracy and may be used with higher-order elements and basis functions using the procedure described in [4].When the source and observation points are close, the potential integrals over wire segments involving the wire kernel are split into parts to handle the singular behavior of the integrand [1]. The singularity characteristics of the gradient of the wire kernel are different than those of the wire kernel, and the axial and radial components have different singularities. The characteristics of the gradient of the wire kernel are discussed in [2]. To evaluate the near electric and magnetic fields of a wire, the integration of the gradient of the wire kernel needs to be calculated over the source wire. Since the vector bases for current have constant direction on linear wire segments, these integrals reduce to integrals of the form

Terahertz generation from laser-driven ultrafast current propagation along a wire target.

PubMed

Zhuo, H B; Zhang, S J; Li, X H; Zhou, H Y; Li, X Z; Zou, D B; Yu, M Y; Wu, H C; Sheng, Z M; Zhou, C T

2017-01-01

Generation of intense coherent THz radiation by obliquely incidenting an intense laser pulse on a wire target is studied using particle-in-cell simulation. The laser-accelerated fast electrons are confined and guided along the surface of the wire, which then acts like a current-carrying line antenna and under appropriate conditions can emit electromagnetic radiation in the THz regime. For a driving laser intensity ∼3×10^{18}W/cm^{2} and pulse duration ∼10 fs, a transient current above 10 KA is produced on the wire surface. The emission-cone angle of the resulting ∼0.15 mJ (∼58 GV/m peak electric field) THz radiation is ∼30^{∘}. The conversion efficiency of laser-to-THz energy is ∼0.75%. A simple analytical model that well reproduces the simulated result is presented.

Reliable Acquisition of RAM Dumps from Intel-Based Apple Mac Computers over FireWire

NASA Astrophysics Data System (ADS)

Gladyshev, Pavel; Almansoori, Afrah

RAM content acquisition is an important step in live forensic analysis of computer systems. FireWire offers an attractive way to acquire RAM content of Apple Mac computers equipped with a FireWire connection. However, the existing techniques for doing so require substantial knowledge of the target computer configuration and cannot be used reliably on a previously unknown computer in a crime scene. This paper proposes a novel method for acquiring RAM content of Apple Mac computers over FireWire, which automatically discovers necessary information about the target computer and can be used in the crime scene setting. As an application of the developed method, the techniques for recovery of AOL Instant Messenger (AIM) conversation fragments from RAM dumps are also discussed in this paper.

Failure analysis of the fractured wires in sternal perichronal loops.

PubMed

Chao, Jesús; Voces, Roberto; Peña, Carmen

2011-10-01

We report failure analysis of sternal wires in two cases in which a perichronal fixation technique was used to close the sternotomy. Various characteristics of the retrieved wires were compared to those of unused wires of the same grade and same manufacturer and with surgical wire specifications. In both cases, wire fracture was un-branched and transgranular and proceeded by a high cycle fatigue process, apparently in the absence of corrosion. However, stress anlysis indicates that the effective stress produced during strong coughing is lower than the yield strength. Our findings suggest that in order to reduce the risk for sternal dehiscence, the diameter of the wire used should be increased. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multicentre experience with the BridgePoint devices to facilitate recanalisation of chronic total coronary occlusions through controlled subintimal re-entry.

PubMed

Werner, Gerald S; Schofer, Joachim; Sievert, Horst; Kugler, Chad; Reifart, Nicolaus J

2011-06-01

The major challenge for the interventional treatment of chronic total coronary occlusion (CTO) is a low primary success rate. A common problem is the passage of the recanalisation wire into a subintimal position. New devices, which were evaluated in the first multicentre study in CTOs resistant to a conventional wire approach, may help to facilitate a controlled re-entry into the true lumen. The aim of this study was to assess the safety and efficacy of this approach, with successful true lumen distal wire passage as the primary endpoint. Forty-two patients were enrolled in four centres with high expertise in PCI for CTOs. All CTOs were of at least three months duration, and were initially attempted with dedicated recanalisation wires. After failure to pass or creation of a subintimal dissection, the BridgePoint devices were applied, consisting of a ball-tipped catheter (CrossBoss) to pass the proximal occlusion cap, and a flat-shaped balloon catheter (Stingray catheter) to be inflated within the subintimal space to guide the re-entry into the true vessel lumen with a special wire (Stingray guidewire). The primary endpoint was met in 67% of all patients. A higher success rate seemed to be possible when all devices were used in sequenced beginning with the CrossBoss, and in the case of a subintimal passage, followed by the Stingray. True lumen re-entry failed because of the loss of distally contrast filling and thus loss of a target for re-entry, and by a failure to advance the Stingray balloon far enough distal and parallel to the distal lumen. There were no severe device related complications. In patients with complex CTOs referred to dedicated centres with high experience in CTOs, these results demonstrate the potential of a guided re-entry from a subintimal wire position by use of the BridgePoint devices.

Explosion symmetry improvement of polyimide-coated tungsten wire in vacuum on negative discharge facility

NASA Astrophysics Data System (ADS)

Li, Mo; Wu, Jian; Lu, Yihan; Li, Xingwen; Li, Yang; Qiu, Mengtong

2018-01-01

Tungsten wire explosion is very asymmetric when fast current rate and insulated coatings are both applied on negative discharge facility using a 24-mm-diameter cathode geometry, which is commonly used on mega-ampere facilities. It is inferred, based on an analytical treatment of the guiding center drift and COMSOL simulations, that the large negative radial electric field causes early voltage breakdown and terminates energy deposition into the wire core on the anode side of the wire. After the anode side is short circuited, the radial electric field along the wire surface on the cathode side will change its polarity and thus leading to additional energy deposition into the wire core. This change causes ˜10 times larger energy deposition and ˜14 times faster explosion velocity in the cathode side than the anode side. In order to reduce this asymmetry, a hollow cylindrical cathode geometry was used to reverse the polarity of radial electric field and was optimized to use on multi-MA facilities. In this case, fully vaporized polyimide-coated tungsten wire with great symmetry improvement was achieved with energy deposition of ˜8.8 eV/atom. The atomic and electronic density distributions for the two different load geometries were obtained by the double-wavelength measurement.

Plasmonic mode converter for controlling optical impedance and nanoscale light-matter interaction.

PubMed

Hung, Yun-Ting; Huang, Chen-Bin; Huang, Jer-Shing

2012-08-27

To enable multiple functions of plasmonic nanocircuits, it is of key importance to control the propagation properties and the modal distribution of the guided optical modes such that their impedance matches to that of nearby quantum systems and desired light-matter interaction can be achieved. Here, we present efficient mode converters for manipulating guided modes on a plasmonic two-wire transmission line. The mode conversion is achieved through varying the path length, wire cross section and the surrounding index of refraction. Instead of pure optical interference, strong near-field coupling of surface plasmons results in great momentum splitting and modal profile variation. We theoretically demonstrate control over nanoantenna radiation and discuss the possibility to enhance nanoscale light-matter interaction. The proposed converter may find applications in surface plasmon amplification, index sensing and enhanced nanoscale spectroscopy.

Impact of different welding techniques on biological effect markers in exhaled breath condensate of 58 mild steel welders.

PubMed

Hoffmeyer, Frank; Raulf-Heimsoth, Monika; Lehnert, Martin; Kendzia, Benjamin; Bernard, Sabine; Berresheim, Hans; Düser, Maria; Henry, Jana; Weiss, Tobias; Koch, Holger M; Pesch, Beate; Brüning, Thomas

2012-01-01

Total mass and composition of welding fumes are predominantly dependent on the welding technique and welding wire applied. The objective of this study was to investigate the impact of welding techniques on biological effect markers in exhaled breath condensate (EBC) of 58 healthy welders. The welding techniques applied were gas metal arc welding with solid wire (GMAW) (n=29) or flux cored wire (FCAW) (n=29). Welding fume particles were collected with personal samplers in the breathing zone inside the helmets. Levels of leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), and 8-isoprostane (8-iso-PGF(2α)) were measured with immunoassay kits and the EBC pH was measured after deaeration. Significantly higher 8-iso-PGF(2α) concentrations and a less acid pH were detected in EBC of welders using the FCAW than in EBC of welders using the GMAW technique. The lowest LTB(4) concentrations were measured in nonsmoking welders applying a solid wire. No significant influences were found in EBC concentrations of PGE(2) based upon smoking status or type of welding technique. This study suggests an enhanced irritative effect in the lower airways of mild steel welders due to the application of FCAW compared to GMAW, most likely associated with a higher emission of welding fumes.

Direct peroral cholangioscopy using an ultrathin endoscope: making technique easier.

PubMed

Sola-Vera, Javier; Uceda, Francisco; Cuesta, Rubén; Vázquez, Narcís

2014-01-01

Cholangioscopy is a useful tool for the study and treatment of biliary pathology. Ultrathin upper endoscopes allow direct peroral cholangioscopy (DPC) but have some drawbacks. The aim of the study was to evaluate the success rate of DPC with an ultrathin endoscope using a balloon catheter to reach the biliary confluence. Prospective observational study. An ultrathin endoscope (Olympus XP180N, outer diameter 5.5 mm, working channel 2 mm) was used. To access the biliary tree, free-hand technique was used. To reach the biliary confluence an intraductal balloon catheter (Olympus B5-2Q diameter 1.9 mm) and a 0.025 inch guide wire was used. In all cases sphincterotomy and/or sphincteroplasty was performed. The success rate was defined as the percentage of cases in which the biliary confluence could be reached with the ultrathin endoscope. Fifteen patients (8 men/7 women) were included. Mean age was 77.7 + or - 10.8 years (range 45-91). The indications for cholangioscopy were suspected bile duct stones (n = 9), electrohydraulic lithotripsy for the treatment of difficult choledocholithiasis (n = 5) and evaluation of biliary stricture (n = 1). Access to the bile duct was achieved in 14/15 cases (93.3%). Biliary confluence was reached in 13/15 cases (86.7%). One complication was observed in one patient (oxigen desaturation). DPC with an ultrathin endoscope can be done with the free-hand technique. Intraductal balloon-guided DPC allows full examination of the common bile duct in most cases.

Metabolomics in chemical ecology.

PubMed

Kuhlisch, Constanze; Pohnert, Georg

2015-07-01

Chemical ecology elucidates the nature and role of natural products as mediators of organismal interactions. The emerging techniques that can be summarized under the concept of metabolomics provide new opportunities to study such environmentally relevant signaling molecules. Especially comparative tools in metabolomics enable the identification of compounds that are regulated during interaction situations and that might play a role as e.g. pheromones, allelochemicals or in induced and activated defenses. This approach helps overcoming limitations of traditional bioassay-guided structure elucidation approaches. But the power of metabolomics is not limited to the comparison of metabolic profiles of interacting partners. Especially the link to other -omics techniques helps to unravel not only the compounds in question but the entire biosynthetic and genetic re-wiring, required for an ecological response. This review comprehensively highlights successful applications of metabolomics in chemical ecology and discusses existing limitations of these novel techniques. It focuses on recent developments in comparative metabolomics and discusses the use of metabolomics in the systems biology of organismal interactions. It also outlines the potential of large metabolomics initiatives for model organisms in the field of chemical ecology.

A two-thermocouple probe technique for estimating thermocouple time constants in flows with combustion: In situ parameter identification of a first-order lag system

NASA Astrophysics Data System (ADS)

Tagawa, M.; Shimoji, T.; Ohta, Y.

1998-09-01

A two-thermocouple probe, composed of two fine-wire thermocouples of unequal diameters, is a novel technique for estimating thermocouple time constants without any dynamic calibration of the thermocouple response. This technique is most suitable for measuring fluctuating temperatures in turbulent combustion. In the present study, the reliability and applicability of this technique are appraised in a turbulent wake of a heated cylinder (without combustion). A fine-wire resistance thermometer (cold wire) of fast response is simultaneously used to provide a reference temperature. A quantitative and detailed comparison between the cold-wire measurement and the compensated thermocouple ones shows that a previous estimation scheme gives thermocouple time constants smaller than appropriate values, unless the noise in the thermocouple signals is negligible and/or the spatial resolution of the two-thermocouple probe is sufficiently high. The scheme has been improved so as to maximize the correlation coefficient between the two compensated-thermocouple outputs. The improved scheme offers better compensation of the thermocouple response. The present approach is generally applicable to in situ parameter identification of a first-order lag system.

Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler

NASA Technical Reports Server (NTRS)

Rodriguez-Ruiz, Juan; Rowles, Russell; Greer, Greg

2011-01-01

A procedure was developed to inject thermal filler material (a paste-like substance) inside the power wire bundle coming from solar arrays. This substance fills in voids between wires, which enhances the heat path and reduces wire temperature. This leads to a reduced amount of heat generated. This technique is especially helpful for current and future generation high-power spacecraft (1 kW or more), because the heat generated by the power wires is significant enough to cause unacceptable overheating to critical components that are in close contact with the bundle.

[Contrast of Z-Pinch X-Ray Yield Measure Technique].

PubMed

Li, Mo; Wang, Liang-ping; Sheng, Liang; Lu, Yi

2015-03-01

Resistive bolometer and scintillant detection system are two mainly Z-pinch X-ray yield measure techniques which are based on different diagnostic principles. Contrasting the results from two methods can help with increasing precision of X-ray yield measurement. Experiments with different load material and shape were carried out on the "QiangGuang-I" facility. For Al wire arrays, X-ray yields measured by the two techniques were largely consistent. However, for insulating coating W wire arrays, X-ray yields taken from bolometer changed with load parameters while data from scintillant detection system hardly changed. Simulation and analysis draw conclusions as follows: (1) Scintillant detection system is much more sensitive to X-ray photons with low energy and its spectral response is wider than the resistive bolometer. Thus, results from the former method are always larger than the latter. (2) The responses of the two systems are both flat to Al plasma radiation. Thus, their results are consistent for Al wire array loads. (3) Radiation form planar W wire arrays is mainly composed of sub-keV soft X-ray. X-ray yields measured by the bolometer is supposed to be accurate because of the nickel foil can absorb almost all the soft X-ray. (4) By contrast, using planar W wire arrays, data from scintillant detection system hardly change with load parameters. A possible explanation is that while the distance between wires increases, plasma temperature at stagnation reduces and spectra moves toward the soft X-ray region. Scintillator is much more sensitive to the soft X-ray below 200 eV. Thus, although the total X-ray yield reduces with large diameter load, signal from the scintillant detection system is almost the same. (5) Both Techniques affected by electron beams produced by the loads.

Making Superconducting Welds between Superconducting Wires

NASA Technical Reports Server (NTRS)

Penanen, Konstantin I.; Eom, Byeong Ho

2008-01-01

A technique for making superconducting joints between wires made of dissimilar superconducting metals has been devised. The technique is especially suitable for fabrication of superconducting circuits needed to support persistent electric currents in electromagnets in diverse cryogenic applications. Examples of such electromagnets include those in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) systems and in superconducting quantum interference devices (SQUIDs). Sometimes, it is desirable to fabricate different parts of a persistent-current-supporting superconducting loop from different metals. For example, a sensory coil in a SQUID might be made of Pb, a Pb/Sn alloy, or a Cu wire plated with Pb/Sn, while the connections to the sensory coil might be made via Nb or Nb/Ti wires. Conventional wire-bonding techniques, including resistance spot welding and pressed contact, are not workable because of large differences between the hardnesses and melting temperatures of the different metals. The present technique is not subject to this limitation. The present technique involves the use (1) of a cheap, miniature, easy-to-operate, capacitor-discharging welding apparatus that has an Nb or Nb/Ti tip and operates with a continuous local flow of gaseous helium and (2) preparation of a joint in a special spark-discharge welding geometry. In a typical application, a piece of Nb foil about 25 m thick is rolled to form a tube, into which is inserted a wire that one seeks to weld to the tube (see figure). The tube can be slightly crimped for mechanical stability. Then a spark weld is made by use of the aforementioned apparatus with energy and time settings chosen to melt a small section of the niobium foil. The energy setting corresponds to the setting of a voltage to which the capacitor is charged. In an experiment, the technique was used to weld an Nb foil to a copper wire coated with a Pb/Sn soft solder, which is superconducting. The joint was evaluated as part of a persistent-current circuit having an inductance of 1 mH. A current was induced in a loop, and no attenuation of the current after a time interval 1,000 s was discernible in a measurement having a fractional accuracy of 10(exp -4): This observation supports the conclusion that the weld had an electrical resistance <10(exp -10) omega.

Metallurgical investigation of wire breakage of tyre bead grade.

PubMed

Palit, Piyas; Das, Souvik; Mathur, Jitendra

2015-10-01

Tyre bead grade wire is used for tyre making application. The wire is used as reinforcement inside the polymer of tyre. The wire is available in different size/section such as 1.6-0.80 mm thin Cu coated wire. During tyre making operation at tyre manufacturer company, wire failed frequently. In this present study, different broken/defective wire samples were collected from wire mill for detailed investigation of the defect. The natures of the defects were localized and similar in nature. The fracture surface was of finger nail type. Crow feet like defects including button like surface abnormalities were also observed on the broken wire samples. The defect was studied at different directions under microscope. Different advanced metallographic techniques have been used for detail investigation. The analysis revealed that, white layer of surface martensite was formed and it caused the final breakage of wire. In this present study we have also discussed about the possible reason for the formation of such kind of surface martensite (hard-phase).

Learning high-quality soldering

NASA Technical Reports Server (NTRS)

Read, W. S.

1981-01-01

Soldering techniques for high-reliability electronic equipment are taught in 5 day course at NASA's Jet Propulsion Laboratory. Topic covered include new circuit assembly, printed-wiring board reworking, circuit changes, wire routing, and component installation.

Electromagnetic Real Time Navigation in the Region of the Posterior Pelvic Ring: An Experimental In-Vitro Feasibility Study and Comparison of Image Guided Techniques.

PubMed

Pishnamaz, Miguel; Wilkmann, Christoph; Na, Hong-Sik; Pfeffer, Jochen; Hänisch, Christoph; Janssen, Max; Bruners, Philipp; Kobbe, Philipp; Hildebrand, Frank; Schmitz-Rode, Thomas; Pape, Hans-Christoph

2016-01-01

Electromagnetic tracking is a relatively new technique that allows real time navigation in the absence of radiation. The aim of this study was to prove the feasibility of this technique for the treatment of posterior pelvic ring fractures and to compare the results with established image guided procedures. Tests were performed in pelvic specimens (Sawbones®) with standardized sacral fractures (Type Denis I or II). A gel matrix simulated the operative approach and a cover was used to disable visual control. The electromagnetic setup was performed by using a custom made carbon reference plate and a prototype stainless steel K-wire with an integrated sensor coil. Four different test series were performed: Group OCT: Optical navigation using preoperative CT-scans; group O3D: Optical navigation using intraoperative 3-D-fluoroscopy; group Fluoro: Conventional 2-D-fluoroscopy; group EMT: Electromagnetic navigation combined with a preoperative Dyna-CT. Accuracy of screw placement was analyzed by standardized postoperative CT-scan for each specimen. Operation time and intraoperative radiation exposure for the surgeon was documented. All data was analyzed using SPSS (Version 20, 76 Chicago, IL, USA). Statistical significance was defined as p< 0.05. 160 iliosacral screws were placed (40 per group). EMT resulted in a significantly higher incidence of optimal screw placement (EMT: 36/40) compared to the groups Fluoro (30/40; p< 0.05) and OCT (31/40; p< 0.05). Results between EMT and O3D were comparable (O3D: 37/40; n.s.). Also, the operation time was comparable between groups EMT and O3D (EMT 7.62 min vs. O3D 7.98 min; n.s.), while the surgical time was significantly shorter compared to the Fluoro group (10.69 min; p< 0.001) and the OCT group (13.3 min; p< 0.001). Electromagnetic guided iliosacral screw placement is a feasible procedure. In our experimental setup, this method was associated with improved accuracy of screw placement and shorter operation time when compared with the conventional fluoroscopy guided technique and compared to the optical navigation using preoperative CT-scans. Further studies are necessary to rule out drawbacks of this technique regarding ferromagnetic objects.

Self-Catalyzed CdTe Wires.

PubMed

Baines, Tom; Papageorgiou, Giorgos; Hutter, Oliver S; Bowen, Leon; Durose, Ken; Major, Jonathan D

2018-04-25

CdTe wires have been fabricated via a catalyst free method using the industrially scalable physical vapor deposition technique close space sublimation. Wire growth was shown to be highly dependent on surface roughness and deposition pressure, with only low roughness surfaces being capable of producing wires. Growth of wires is highly (111) oriented and is inferred to occur via a vapor-solid-solid growth mechanism, wherein a CdTe seed particle acts to template the growth. Such seed particles are visible as wire caps and have been characterized via energy dispersive X-ray analysis to establish they are single phase CdTe, hence validating the self-catalysation route. Cathodoluminescence analysis demonstrates that CdTe wires exhibited a much lower level of recombination when compared to a planar CdTe film, which is highly beneficial for semiconductor applications.

Reliability improvement of 1 mil aluminum wire bonds for semiconductors, technical performance summary

NASA Technical Reports Server (NTRS)

1971-01-01

The reliability of semiconductor devices as influenced by the reliability of wire bonds used in the assembly of the devices is investigated. The specific type of failure dealt with involves fracture of wire bonds as a result of repeated flexure of the wire at the heel of the bond when the devices are operated in an on-off mode. The mechanism of failure is one of induced fracture of the wire. To improve the reliability of a chosen transistor, one-mil diameter wires of aluminum with various alloy additions were studied using an accelerated fatigue testing machine. In addition, the electroprobe was used to study the metallurgy of the wires as to microstructure and kinetics of the growth of insoluble phases. Thermocompression and ultrasonic bonding techniques were also investigated.

Synchronized Re-Entrant Flux Reversal of Multiple FeSiB Amorphous Wires Having the Larger Output

NASA Astrophysics Data System (ADS)

Takajo, Minoru; Yamasaki, Jiro

Technique to synchronize the re-entrant flux reversal of the multiple magnetostrictive Fe77.5Si7.5B15 amorphous wires was developed using a flux keeper of amorphous ribbons contacted to the wire ends. It is comprehended that the characteristics of the re-entrant flux takes place respectively at almost the same time in the three Fe-Si-B amorphous wires with a diameter of 65, 95μm. This phenomenon can be explained by considering the strong magnetic coupling of wires and amorphous ribbon by stray field from the each wire ends. As a result, the magnitude of the induced voltage in the sense coil is increased in proportion to the multiplication of the number of the wires.

Mechanical properties of nickel-titanium archwire used in the final treatment phase of Tip-Edge Plus technique: an in vitro study.

PubMed

Shen, Xiao; Sun, Xin-hua; Tian, Hua; Zhang, Chun-bo; Yan, Kuo; Guo, Yong-liang

2013-01-01

As the only active component in final treatment phase of Tip-Edge Plus technique, the activation of nickel-titanium orthodontic archwires is one of the factors that affect the torque expression. It is necessary to evaluate the mechanical properties of the nickel-titanium wire used in the final treatment phase in simulated oral environments to forecast the treatment outcomes. The mechanical properties of 171 thermal nickel-titanium wires of 0.35 mm (0.014-in) in diameters with different deflection of 40 mm in length were investigated with three-point bending test. The samples were divided into 2 groups: as-received and bended groups. In the bended group, samples were divided into 7 subgroups according to the amounts of deflection and named by the canine angulations (-25°, -19°, -13°, -7°, -1°, +5°, +11°). The deflection of wires was made by inserting the wires into the deep tunnel of Tip-Edge Plus brackets positioned in plaster casts with different canine angulations to mimic the use of nickel-titanium wires in the final treatment phase. Immersed the bended group in artificial saliva (pH 6.8) and preserved at 37.0°C. Eight durations of incubation were tested: 1 to 8 weeks. Three analogous samples of each group and subgroups were tested per week. Stiffness (YS:E) and the load-deflection characteristics of unloading plateau section were obtained. Significant changes in specific mechanical properties were observed in long-term immersed and large deflected wires compared with as-received groups. Both immersion time and deflection affected the mechanical properties of wires in the simulated oral environment, and the two factors had synergistic effect. In groups -25°, -19° and -13°, stiffness (YS:E) increased then decreased and average plateau force and ratio of variance decreased then increased correspondingly at specific time. In the final treatment phase of Tip-Edge Plus technique, the mechanical properties of nickel-titanium wire are associated with the using time and amounts of deflection and it may affect treatment outcomes. As the main reason for wire deflection, canine crown angulation plays an important role in the wire performance. It may be wise to focus on the canine crown angulations and using time in clinic with Tip-Edge Plus technique and make proper adjustment to help to make sure the treatment outcomes.

Welding skate with computerized controls

NASA Technical Reports Server (NTRS)

Wall, W. A., Jr.

1968-01-01

New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.

Blast Coating of Superelastic NiTi Wire with PTFE to Enhance Wear Properties

NASA Astrophysics Data System (ADS)

Dunne, Conor F.; Roche, Kevin; Twomey, Barry; Hodgson, Darel; Stanton, Kenneth T.

2015-03-01

This work investigates the deposition of polytetrafluoroethylene (PTFE) onto a superelastic NiTi wire using an ambient temperature-coating technique known as CoBlast. The process utilises a stream of abrasive (Al2O3) and a coating medium (PTFE) sprayed simultaneously at the surface of the substrate. Superelastic NiTi wire is used in guidewire applications, and PTFE coatings are commonly applied to reduce damage to vessel walls during insertion and removal, and to aid in accurate positioning by minimising the force required to advance, retract or rotate the wire. The CoBlast coated wires were compared to wire treated with PTFE only. The coated samples were examined using variety of techniques: X-ray diffraction (XRD), microscopy, surface roughness, wear testing and flexural tests. The CoBlast coated samples had an adherent coating with a significant resistance to wear compared to the samples coated with PTFE only. The XRD revealed that the process gave rise to a stress-induced martensite phase in the NiTi which may enhance mechanical properties. The study indicates that the CoBlast process can be used to deposit thin adherent coatings of PTFE onto the surface of superelastic NiTi.

Synergistic responses of superficial chemistry and micro topography of titanium created by wire-type electric discharge machining.

PubMed

Kataoka, Yu; Tamaki, Yukimichi; Miyazaki, Takashi

2011-01-01

Wire-type electric discharge machining has been applied to the manufacture of endosseous titanium implants as this computer associated technique allows extremely accurate complex sample shaping with an optimal micro textured surface during the processing. Since the titanium oxide layer is sensitively altered by each processing, the authors hypothesized that this technique also up-regulates biological responses through the synergistic effects of the superficial chemistry and micro topography. To evaluate the respective in vitro cellular responses on the superficial chemistry and micro topography of titanium surface processed by wire-type electric discharge, we used titanium-coated epoxy resin replica of the surface. An oxide layer on the titanium surface processed by wire-type electric discharge activated the initial responses of osteoblastic cells through an integrin-mediated mechanism. Since the mRNA expression of ALP on those replicas was up-regulated compared to smooth titanium samples, the micro topography of a titanium surface processed by wire-type electric discharge promotes the osteogenic potential of cells. The synergistic response of the superficial chemistry and micro topography of titanium processed by wire-type electric discharge was demonstrated in this study.

Simultaneous measurement of temperature and strain using four connecting wires

NASA Technical Reports Server (NTRS)

Parker, Allen R., Jr.

1993-01-01

This paper describes a new signal-conditioning technique for measuring strain and temperature which uses fewer connecting wires than conventional techniques. Simultaneous measurement of temperature and strain has been achieved by using thermocouple wire to connect strain gages to signal conditioning. This signal conditioning uses a new method for demultiplexing sampled analog signals and the Anderson current loop circuit. Theory is presented along with data to confirm that strain gage resistance change is sensed without appreciable error because of thermoelectric effects. Furthermore, temperature is sensed without appreciable error because of voltage drops caused by strain gage excitation current flowing through the gage resistance.

External wire-frame fixation of digital skin grafts: a non-invasive alternative to the K-wire insertion method.

PubMed

Huang, Chenyu; Ogawa, Rei; Hyakusoku, Hiko

2014-08-01

The current skin graft fixation methods for digits, including the Kirschner wire insertion technique, can be limited by inadequate or excessive fixation and complications such as infection or secondary injuries. Therefore, the external wire-frame fixation method was invented and used for skin grafting of digits. This study aimed to investigate external wire-frame fixation of digital skin grafts as a non-invasive alternative to the K-wire insertion method. In 2005-2012, 15 patients with burn scar contractures on the hand digits received a skin graft that was then fixed with an external wire frame. The intra-operative time needed to make the wire frame, the postoperative time to frame and suture removal, the graft survival rate, the effect of contracture release and the complications were recorded. In all cases, the contracture release was 100%. The complete graft survival rate was 98.6%. Four patients had epithelial necrosis in <5% of the total area. There were no other complications such as pressure ulcer or hypoxia of fingers. External wire-frame fixation is simple, minimally invasive and a custom-made technique for skin grafting of the fingers. It was designed for its potential benefits and the decreased risk it poses to patients with scar contractures on their fingers. It can be implemented in three phases of grafting, does not affect the epiphyseal line or subsequent finger growth and is suitable for children with multi-digit involvement. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

In Situ Electrochemical Deposition of Microscopic Wires

NASA Technical Reports Server (NTRS)

Yun, Minhee; Myung, Nosang; Vasquez, Richard

2005-01-01

A method of fabrication of wires having micron and submicron dimensions is built around electrochemical deposition of the wires in their final positions between electrodes in integrated circuits or other devices in which the wires are to be used. Heretofore, nanowires have been fabricated by a variety of techniques characterized by low degrees of controllability and low throughput rates, and it has been necessary to align and electrically connect the wires in their final positions by use of sophisticated equipment in expensive and tedious post-growth assembly processes. The present method is more economical, offers higher yields, enables control of wire widths, and eliminates the need for post-growth assembly. The wires fabricated by this method could be used as simple electrical conductors or as transducers in sensors. Depending upon electrodeposition conditions and the compositions of the electroplating solutions in specific applications, the wires could be made of metals, alloys, metal oxides, semiconductors, or electrically conductive polymers. In this method, one uses fabrication processes that are standard in the semiconductor industry. These include cleaning, dry etching, low-pressure chemical vapor deposition, lithography, dielectric deposition, electron-beam lithography, and metallization processes as well as the electrochemical deposition process used to form the wires. In a typical case of fabrication of a circuit that includes electrodes between which microscopic wires are to be formed on a silicon substrate, the fabrication processes follow a standard sequence until just before the fabrication of the microscopic wires. Then, by use of a thermal SiO-deposition technique, the electrodes and the substrate surface areas in the gaps between them are covered with SiO. Next, the SiO is electron-beam patterned, then reactive-ion etched to form channels having specified widths (typically about 1 m or less) that define the widths of the wires to be formed. Drops of an electroplating solution are placed on the substrate in the regions containing the channels thus formed, then the wires are electrodeposited from the solution onto the exposed portions of the electrodes and into the channels. The electrodeposition is a room-temperature, atmospheric-pressure process. The figure shows an example of palladium wires that were electrodeposited into 1-mm-wide channels between gold electrodes.

New perspectives on neuronal development via microfluidic environments

PubMed Central

Millet, Larry J.; Gillette, Martha U.

2012-01-01

Understanding the signals that guide neuronal development and direct formation of axons, dendrites, and synapses during wiring of the brain is a fundamental challenge of developmental neuroscience. Discovering how local signals shape developing neurons has been impeded by the inability of conventional culture methods to interrogate micro-environments of complex neuronal cytoarchitectures, where different sub-domains encounter distinct chemical, physical, and fluidic features. Micro-fabrication techniques are enabling the creation of micro-environments tailored to neuronal structures and sub-domains, with unprecedented access and control. The design, fabrication, and properties of microfluidic devices offer significant advantages for addressing unresolved issues of neuronal development. These high-resolution approaches are poised to contribute new insights into mechanisms for restoring neuronal function and connectivity compromised by injury, stress, and neurodegeneration. PMID:23031246

Horizontal Advanced Tensiometer

DOEpatents

Hubbell, Joel M.; Sisson, James B.

2004-06-22

An horizontal advanced tensiometer is described that allows the monitoring of the water pressure of soil positions, particularly beneath objects or materials that inhibit the use of previous monitoring wells. The tensiometer includes a porous cup, a pressure transducer (with an attached gasket device), an adaptive chamber, at least one outer guide tube which allows access to the desired horizontal position, a transducer wire, a data logger and preferably an inner guide tube and a specialized joint which provides pressure on the inner guide tube to maintain the seal between the gasket of the transducer and the adaptive chamber.

K-wire and tension band wire fixation in treating sternoclavicular joint dislocation.

PubMed

Chen, Qing-yu; Cheng, Shao-wen; Wang, Wei; Lin, Zhong-qin; Zhang, Wei; Kou, Dong-quan; Shen, Yue; Ying, Xiao-zhou; Cheng, Xiao-jie; Lv, Chuan-zhu; Peng, Lei

2011-02-01

To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique. This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years (range, 9-62 years). The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4 right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations. All patients were followed up for 6 to 24 months, 10 months on average. According to Rockwood's rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88, and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation, etc. Patients were all satisfied with the anatomical reduction and functional recovery. The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages.

Posterior spinal osteosynthesis for cervical fracture/dislocation using a flexible multistrand cable system: technical note.

PubMed

Huhn, S L; Wolf, A L; Ecklund, J

1991-12-01

Cervical instability secondary to fracture/dislocation or traumatic subluxation involving the posterior elements may be treated by a variety of fusion techniques. The rigidity of the stainless steel wires used in posterior cervical fusions often leads to difficulty with insertion, adequate tension, and conformation of the graft construct. This report describes a technique of posterior cervical fusion employing a wire system using flexible stainless steel cables. The wire consists of a flexible, 49-strand, stainless steel cable connected on one end to a short, malleable, blunt leader with the opposite end connected to a small islet. The cable may be used in occipitocervical, atlantoaxial, facet-to-spinous process, and interspinous fusion techniques. The cable loop is secured by using a tension/crimper device that sets the desired tension in the cable. In addition to superior biomechanical strength, the flexibility of the cable allows greater ease of insertion and tension adjustment. In terms of direct operative instrumentation in posterior cervical arthrodesis, involving both the upper and lower cervical spine, the cable system appears to be a safe and efficient alternative to monofilament wires.

Measuring Surface Tension of a Flowing Soap Film

NASA Astrophysics Data System (ADS)

Sane, Aakash; Kim, Ildoo; Mandre, Shreyas

2016-11-01

It is well known that surface tension is sensitive to the presence of surfactants and many conventional methods exist to measure it. These techniques measure surface tension either by intruding into the system or by changing its geometry. Use of conventional methods in the case of a flowing soap film is not feasible because intruding the soap film changes surface tension due to Marangoni effect. We present a technique in which we measure the surface tension in situ of a flowing soap film without intruding into the film. A flowing soap film is created by letting soap solution drip between two wires. The interaction of the soap film with the wires causes the wires to deflect which can be measured. Surface tension is calculated using a relation between curvature of the wires and the surface tension. Our measurements indicate that the surface tension of the flowing soap film for our setup is around 0.05 N/m. The nature of this technique makes it favorable for measuring surface tension of flowing soap films whose properties change on intrusion.

Two-step tunneling technique of deep brain stimulation extension wires-a description.

PubMed

Fontaine, Denys; Vandersteen, Clair; Saleh, Christian; von Langsdorff, Daniel; Poissonnet, Gilles

2013-12-01

While a significant body of literature exists on the intracranial part of deep brain stimulation surgery, the equally important second part of the intervention related to the subcutaneous tunneling of deep brain stimulation extension wires is rarely described. The tunneling strategy can consist of a single passage of the extension wires from the frontal incision site to the subclavicular area, or of a two-step approach that adds a retro-auricular counter-incision. Each technique harbors the risk of intraoperative and postoperative complications. At our center, we perform a two-step tunneling procedure that we developed based on a cadaveric study. In 125 consecutive patients operated since 2002, we did not encounter any complication related to our tunneling method. Insufficient data exist to fully evaluate the advantages and disadvantages of each tunneling technique. It is of critical importance that authors detail their tunneling modus operandi and report the presence or absence of complications. This gathered data pool may help to formulate a definitive conclusions on the safest method for subcutaneous tunneling of extension wires in deep brain stimulation.

A biomechanical comparison of three sternotomy closure techniques.

PubMed

Cohen, David J; Griffin, Lanny V

2002-02-01

A biomechanical study of three sternotomy closure techniques (figure-of-eight stainless-steel wires, Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates, and figure-of-eight stainless-steel cables) was conducted to compare strength and stiffness variables in three clinically relevant loading modes (anterior-posterior shear, longitudinal shear, and lateral distraction). All tests were conducted on polyurethane foam sternal models that simulate the properties of cancellous bone. Each model was divided longitudinally and reconstructed using one of the sternotomy closure repair techniques. Tests were performed using a materials testing system that applies a continuously increasing amount of force in one direction to the model until it catastrophically breaks. A total of six trials of each fixation type in each of three test groups were prepared and tested, for a total of 54 tests. Strength and stiffness variables as well as a post-yield analysis of failure were evaluated. Sternums repaired using the DSF plate system are a more rigid construct than sternums repaired using the stainless-steel wires or cables in the distraction and transverse shear modes and they are not significantly different from sternums repaired with wires or cables in the longitudinal shear mode. The DSF plate system offers a 25% improvement in resistance to failure (yield) compared to wires when a transverse shear force is applied to the model. The cable system had a higher resistance to failure than the wires in all modes although the differences were not statistically significant. Additionally, the DSF plate system provides substantial reduction of the implant's cutting into the sternal model under loading as evidenced by the post-yield displacement when compared with either cables or wires for the distraction and longitudinal shear modes. For the transverse shear mode, the cables or wires would completely fail at the load for which cutting begins for the DSF. Both the DSF plate system and the stainless-steel cable system offer important advantages over figure-of-eight wire for sternal closure.

[Methods of resolution for haptic assistance during catheterization].

PubMed

Kern, T A; Herrmann, J; Klages, S; Meiss, T; Werthschützky, R

2005-01-01

During catheterization navigation within the patient is mainly dependent on a live x-ray image on the screen. Although methods for 3D visualisation and remote navigation of the catheter are discussed and tested still precise positioning is merely the result of intense training and a high skill and level of training of the performing surgeon. This article refers to a system which can be considered as an add-on for existing procedures of catheterization. It compromises of a miniaturised force sensor located at the tip of guide-wires whose prototype is shown here. The measured forces will be presented to the surgeon amplified by an external actuator described in this article. As a result a haptic perception of the forces between the tip of the guide-wire and the vessels walls will be available and enable the surgeon to gain an impression which is comparable to palpation of living vessels from the inside

Diminishing detonator effectiveness through electromagnetic effects

DOEpatents

Schill, Jr, Robert A.

2016-09-20

An inductively coupled transmission line with distributed electromotive force source and an alternative coupling model based on empirical data and theory were developed to initiate bridge wire melt for a detonator with an open and a short circuit detonator load. In the latter technique, the model was developed to exploit incomplete knowledge of the open circuited detonator using tendencies common to all of the open circuit loads examined. Military, commercial, and improvised detonators were examined and modeled. Nichrome, copper, platinum, and tungsten are the detonator specific bridge wire materials studied. The improvised detonators were made typically made with tungsten wire and copper (.about.40 AWG wire strands) wire.

A review of wiring system safety in space power systems

NASA Technical Reports Server (NTRS)

Stavnes, Mark W.; Hammoud, Ahmad N.

1993-01-01

Wiring system failures have resulted from arc propagation in the wiring harnesses of current aerospace vehicles. These failures occur when the insulation becomes conductive upon the initiation of an arc. In some cases, the conductive path of the carbon arc track displays a high enough resistance such that the current is limited, and therefore may be difficult to detect using conventional circuit protection. Often, such wiring failures are not simply the result of insulation failure, but are due to a combination of wiring system factors. Inadequate circuit protection, unforgiving system designs, and careless maintenance procedures can contribute to a wiring system failure. This paper approaches the problem with respect to the overall wiring system, in order to determine what steps can be taken to improve the reliability, maintainability, and safety of space power systems. Power system technologies, system designs, and maintenance procedures which have led to past wiring system failures will be discussed. New technologies, design processes, and management techniques which may lead to improved wiring system safety will be introduced.

Ultrasound-Guided Vascular Access Simulator for Medical Training: Proposal of a Simple, Economic and Effective Model.

PubMed

Fürst, Rafael Vilhena de Carvalho; Polimanti, Afonso César; Galego, Sidnei José; Bicudo, Maria Claudia; Montagna, Erik; Corrêa, João Antônio

2017-03-01

To present a simple and affordable model able to properly simulate an ultrasound-guided venous access. The simulation was made using a latex balloon tube filled with water and dye solution implanted in a thawed chicken breast with bones. The presented model allows the simulation of all implant stages of a central catheter. The obtained echogenicity is similar to that observed in human tissue, and the ultrasound identification of the tissues, balloon, needle, wire guide and catheter is feasible and reproducible. The proposed model is simple, economical, easy to manufacture and capable of realistically and effectively simulating an ultrasound-guided venous access.

Nail-like targets for laser plasma interaction experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasley, J; Wei, M; Shipton, E

2007-12-18

The interaction of ultra-high power picosecond laser pulses with solid targets is of interest both for benchmarking the results of hybrid particle in cell (PIC) codes and also for applications to re-entrant cone guided fast ignition. We describe the construction of novel targets in which copper/titanium wires are formed into 'nail-like' objects by a process of melting and micromachining, so that energy can be reliably coupled to a 24 {micro}m diameter wire. An extreme-ultraviolet image of the interaction of the Titan laser with such a target is shown.

A fast response, low heat generating activation method for LHe level sensors

NASA Astrophysics Data System (ADS)

Choudhury, Anup; Sahu, Santosh; Kanjilal, Dinakar

2018-06-01

A superconducting liquid helium (LHe) level sensor of length 300 mm has been fabricated based on the principle of differential heat transfer characteristic in helium gas compared to that in liquid. The sensor wire used has a diameter of 38 μm, and the wire was obtained from a pack of multifilament wires. A full thermo-electrical characterisation of the sensor was carried out in a dedicated setup. Its dynamic thermal response was also studied to understand its timing characteristics at different liquid levels and excitation currents. Based on the sensor characterisation, a new level measurement technique is evaluated which can reduce the heat load going to LHe during sensor activation without compromising on its sensitivity or accuracy. The timing response with this technique will make the level detection faster compared to the conventional techniques.

New devices for flow measurements: Hot film and burial wire sensors, infrared imagery, liquid crystal, and piezo-electric model

NASA Technical Reports Server (NTRS)

Mcree, Griffith J., Jr.; Roberts, A. Sidney, Jr.

1991-01-01

An experimental program aimed at identifying areas in low speed aerodynamic research where infrared imaging systems can make significant contributions is discussed. Implementing a new technique, a long electrically heated wire was placed across a laminar flow. By measuring the temperature distribution along the wire with the IR imaging camera, the flow behavior was identified.

Optimizing pediatric interdental fixation by use of a paramedian palatal fixation site.

PubMed

McNichols, Colton H; Hatef, Daniel A; Cole, Patrick D; Hollier, Larry H

2012-03-01

Condylar fractures are the most common injury seen in pediatric mandibular trauma. These injuries often cannot be adequately stabilized by conservative techniques such as splinting. The pediatric condyle fracture often requires a period of intermaxillary fixation. Because of the characteristics of the developing dentition, circumdental wiring is often not possible. Surgeons commonly achieve interdental stabilization by the connection of a circum-mandibular wire and a second wire placed through a drill hole in the piriform aperture. This method can be problematic in the young patient whose palatal suture is still patent. In this brief technical note, the use of a paramedian drill hole through the palate posterior to the maxillary incisors is described. It is believed that this method is superior to other techniques because it avoids injury to the deciduous tooth buds and allows for the maxillary wire to be seated in more structurally sound tissues.

Antenna coupled photonic wire lasers

DOE PAGES

Kao, Tsung-Kao; Cai, Xiaowei; Lee, Alan W. M.; ...

2015-06-22

Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to extract power from wire lasers using monolithically integrated antennas. These integrated antennas significantly increase the effective radiation area, and consequently enhance the power extraction efficiency. When applied to wire lasers at THz frequency, we achieved the highest single-side slope efficiency (~450more » mW/A) in pulsed mode for DFB lasers at 4 THz and a ~4x increase in output power at 3 THz compared with a similar structure without antennas. This work demonstrates the versatility of incorporating microwave engineering techniques into laser designs, enabling significant performance enhancements.« less

Feasibility Study for Casting of High Temperature Refractory Superalloy Composites

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.

1998-01-01

Abstract This study investigated the feasibility of using conventional casting technique to fabricate refractory wires reinforced superalloy composites. These composites were being developed for advanced rocket engine turbine blades and other high temperature applications operating up to 2000 F. Several types of refractory metal wires such as W- Th, W-Re, Mo-Hf-C and W-HF-C reinforced waspaloy were experimentally cast and heat treated at 2000 F up to 48 hrs. Scanning electron microscope analysis was conducted in regions adjacent to the wire-matrix interface to determine the reaction zone and chemical compatibility resulting from material interdiffusion. It was concluded that fabrication using conventional casting may be feasible because the wire-matrix reaction zone thickness was comparable to similar composites produced by arc-sprayed monotape with hot isostatic pressing technique, Moreover, it was also found that the chemical compatibility could be improved significantly through a slight modification of the superalloy matrix compositions.

Oxidation of High-temperature Alloy Wires in Dry Oxygen and Water Vapor

NASA Technical Reports Server (NTRS)

Opila, Elizabeth J.; Lorincz, Jonathan A.; DeMange, Jeffrey J.

2004-01-01

Small diameter wires (150 to 250 microns) of the high temperature alloys Haynes 188, Haynes 230, Haynes 230, Haynes 214, Kanthal Al and PM2000 were oxidized at 1204 C in dry oxygen or 50% H2O /50% O2 for 70 Hours. The oxidation kinetics were monitored using a thermogravimetric technique. Oxide phase composition and morphology of the oxidized wires were determined by X-ray diffraction,field emission scanning electron microscopy, and energy dispersive spectroscopy. The alumina-forming alloys, Kanthal Al and PM2000, out-performed the chromia-forming alloys under this conditions. PM2000 was recommended as the most promising candidate for advanced hybrid seal applications for space reentry control surface seals or hypersonic propulsion system seals. This study also demonstrated that thermogravimetric analysis of small diameter wires is a powerful technique for the study of oxide volatility, oxide adherence, and breakaway oxidation.

LENR BEC Clusters on and below Wires through Cavitation and Related Techniques

NASA Astrophysics Data System (ADS)

Stringham, Roger; Stringham, Julie

2011-03-01

During the last two years I have been working on BEC cluster densities deposited just under the surface of wires, using cavitation, and other techniques. If I get the concentration high enough before the clusters dissipate, in addition to cold fusion related excess heat (and other effects, including helium-4 formation) I anticipate that it may be possible to initiate transient forms of superconductivity at room temperature.

Effect of Bypass Capacitor in Common-mode Noise Reduction Technique for Automobile PCB

NASA Astrophysics Data System (ADS)

Uno, Takanori; Ichikawa, Kouji; Mabuchi, Yuichi; Nakamura, Atushi

In this letter, we studied the use of common mode noise reduction technique for in-vehicle electronic equipment, each comprising large-scale integrated circuit (LSI), printed circuit board (PCB), wiring harnesses, and ground plane. We have improved the model circuit of the common mode noise that flows to the wire harness to add the effect of by-pass capacitors located near an LSI.

Effect of bending on the performance of spool-packaged shape memory alloy actuators

NASA Astrophysics Data System (ADS)

Redmond, John A.; Brei, Diann; Luntz, Jonathan; Browne, Alan L.; Johnson, Nancy L.

2009-03-01

Shape memory alloy (SMA) actuation is becoming an increasingly viable technology for industrial applications as many of the technical issues that have limited its use are being addressed (speed of actuation, mechanical connections, performance degradation, quality control, etc.) while increasing production capacities drive costs to practical levels. Shape memory alloys are often selected because of their high energy density which can lead to compact actuators; however, wire forms with small cross-sectional diameters tend to be long (10 to 50 times the length of required stroke). Spooling the wire can be used for compact packaging, but as the spool diameter decreases performance losses and fatigue increase due to bending strains and stresses. This paper presents a simple, design-level model for spooled SMA wire actuators with linear motion outputs that includes the effects of friction and wire bending and accounts for the actuator geometry, applied load, and material friction and constitutive properties. The model was validated experimentally with respect to the ratio of mandrel to SMA wire diameter and agrees well in both form and magnitude with experiments. The resulting model provides the framework for the analysis and synthesis of spooled SMA wire actuators to guide the selection of design parameters with respect to the tradeoffs between performance and packaging.

Application of Ampere’s law to a non-infinite wire and to a moving charge

NASA Astrophysics Data System (ADS)

Aledealat, K.; Duston, C. L.

2018-07-01

In this work we demonstrate how to apply Ampere’s law to a non-infinite wire that is a part of a complete circuit with a steady current. We show that this can be done by considering the magnetic field from the whole circuit, without having to directly introduce the displacement current. This example can be used to isolate and clarify students’ confusion about the application of Ampere’s law to a short wire. The second part of this work focuses on the application of Ampere’s law to a non-relativistic moving charge. It exposes the students to the Dirac delta function in a physical example and guides them to finding the magnetic field of a moving charge in a reasonable way.

The Application of Ultrasonic Inspection to Crimped Electrical Connections

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2010-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The development of a prototype instrument, based on a modified, commercially available, crimp tool, is demonstrated for applying this technique when wire crimps are installed. The crimp tool has three separate crimping locations that accommodate the three different ferrule diameters. The crimp tool in this study is capable of crimping wire diameters ranging from 12 to 26 American Wire Gauge (AWG). A transducer design is presented that allows for interrogation of each of the three crimp locations on the crimp tool without reconfiguring the device. An analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse is shown to correlate to both crimp location in the tool and the AWG of the crimp/ferrule combination. The detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, is discussed. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process.

Guiding of High Laser Intensities in Long Plasma Channels

NASA Astrophysics Data System (ADS)

Levin, M.; Eisenmann, S.; Palchan, T.; Zigler, A.; Sugiyama, K.; Nakajima, K.; Kaganovich, D.; Hubbard, R. F.; Ting, A.; Gordon, D. F.; Sprangle, P.; Fraenkel, M.; Maman, S.; Henis, Z.

Plasma channels have been widely used to guide intense laser pulses over many Rayleigh lengths. Using optimized segmented capillary discharges, we demonstrated guided propagation of ultra short (100 fs) high intensity (1016 W/cm-2, limited by the laser system) pulses over distances up to 12.6 cm and intensities above 1018W/cm2 for 1.5cm boron nitride capillary. Both radial and longitudinal density profiles of plasma channels were studied under various discharge conditions. A new diagnostic technique is presented in which the transport of a guided laser pulse at different delay times from the initiation of the discharge is sampled on a single discharge shot. Using external, 10 nsec Nd YAG laser of several tenths of milijoules to ignite polyethylene capillaries we have demonstrated channels of various length in density range of 1017 - 1019 cm-3 and up to 25% deep. The longitudinal profiles were found to be remarkably uniform in both short and long capillaries. The Boron Nitride capillary has provided a guiding medium that can withstand more than 1000 shots. Using these capillaries we have guided laser intensities above 1018W/cm2. The laser ignition of capillary discharge provided reliable almost jitter free approach. The concerns related to influence of relatively high current density flow through capillary on the injected electrons were studied extensively by us both theoretically and experimentally using a simple injection method. The method is based on the interaction of a high intensity laser pulse with a thin wire placed near capillary entrance. The influence of magnetic fields was found to be insignificant. Using this method we have studied transport of electrons though capillary discharge.

Comparative study between the results of effective index based matrix method and characterization of fabricated SU-8 waveguide

NASA Astrophysics Data System (ADS)

Samanta, Swagata; Dey, Pradip Kumar; Banerji, Pallab; Ganguly, Pranabendu

2017-01-01

A study regarding the validity of effective-index based matrix method (EIMM) for the fabricated SU-8 channel waveguides is reported. The design method is extremely fast compared to other existing numerical techniques, such as, BPM and FDTD. In EIMM, the effective index method was applied in depth direction of the waveguide and the resulted lateral index profile was analyzed by a transfer matrix method. By EIMM one can compute the guided mode propagation constants and mode profiles for each mode for any dimensions of the waveguides. The technique may also be used to design single mode waveguide. SU-8 waveguide fabrication was carried out by continuous-wave direct laser writing process at 375 nm wavelength. The measured propagation losses of these wire waveguides having air and PDMS as superstrates were 0.51 dB/mm and 0.3 dB/mm respectively. The number of guided modes, obtained theoretically as well as experimentally, for air-cladded waveguide was much more than that of PDMS-cladded waveguide. We were able to excite the isolated fundamental mode for the later by precise fiber positioning, and mode image was recorded. The mode profiles, mode indices, and refractive index profiles were extracted from this mode image of the fundamental mode which matched remarkably well with the theoretical predictions.

Investigation of Axial Electric Field Measurements with Grounded-Wire TEM Surveys

NASA Astrophysics Data System (ADS)

Zhou, Nan-nan; Xue, Guo-qiang; Li, Hai; Hou, Dong-yang

2018-01-01

The grounded-wire transient electromagnetic (TEM) surveying is often performed along the equatorial direction with its observation lines paralleling to the transmitting wire with a certain transmitter-receiver distance. However, such method takes into account only the equatorial component of the electromagnetic field, and a little effort has been made on incorporating the other major component along the transmitting wire, here denoted as axial field. To obtain a comprehensive understanding of its fundamental characteristics and guide the designing of the corresponding observation system for reliable anomaly detection, this study for the first time investigates the axial electric field from three crucial aspects, including its decay curve, plane distribution, and anomaly sensitivity, through both synthetic modeling and real application to one major coal field in China. The results demonstrate a higher sensitivity to both high- and low-resistivity anomalies by the electric field in axial direction and confirm its great potentials for robust anomaly detection in the subsurface.

Gold nanoparticles prepared by electro-exploding wire technique in aqueous solutions

NASA Astrophysics Data System (ADS)

Kumar, Lalit; Kapoor, Akanksha; Meghwal, Mayank; Annapoorni, S.

2016-05-01

This article presents an effective approach for the synthesis of Au nanoparticles via an environmentally benevolent electro-exploding wire (EEW) technique. In this process, Au nanoparticles evolve through the plasma generated from the parent Au metal. Compared to other typical chemical methods, electro-exploding wire technique is a simple and economical technique which normally operates in water or organic liquids under ambient conditions. Efficient size control was achieved using different aqueous medium like (1mM) NaCl, deionized water and aqueous solution of sodium hydroxide (NaOH, pH 9.5) using identical electro-exploding conditions. The gold nanoparticles exhibited the UV-vis absorption spectrum with a maximum absorption band at 530 nm, similar to that of gold nanoparticles chemically prepared in a solution. The mechanism of size variation of Au nanoparticles is also proposed. The results obtained help to develop methodologies for the control of EEW based nanoparticle growth and the functionalization of nanoparticle surfaces by specific interactions.

Form measurement of a 0.1 mm diameter wire with a chromatic confocal sensor, with associated uncertainty evaluation

NASA Astrophysics Data System (ADS)

Sanz, Claude; Giusca, Claudiu; Morantz, Paul; Marin, Antonio; Chérif, Ahmed; Schneider, Jürgen; Mainaud-Durand, Hélène; Shore, Paul; Steffens, Norbert

2018-07-01

The accurate characterisation of a copper–beryllium wire with a diameter of 0.1 mm is one of the steps to increase the precision of future accelerators’ pre-alignment. Novelties in measuring the wire properties were found in order to overcome the difficulties brought by its small size. This paper focuses on an implementation of a chromatic-confocal sensor leading to a sub-micrometric uncertainty on the form measurements. Hence, this text reveals a high-accuracy metrology technique applicable to objects with small diameters: it details the methodology, describes a validation by comparison with a reference and specifies the uncertainty budget of this technique.

Straight-wire appliances: standard versus individual prescription.

PubMed

Farronato, Giampietro; Periti, Giulia; Giannini, Lucia; Farronato, Davide; Maspero, Cinzia

2009-01-01

In this article the individual patient (IP) appliance is described. It consists of 250 options of bracket and band variations as the straight wire appliances. Increasing the bracket capabilities means using an increasing number of brackets, each with a specific design created for a treatment situation. The objective of IP appliance is to eliminate wire bending from orthodontic treatment and improve the treatment results. To manage this technique, a computer software is needed. Internet offers significant possibilities in managing each patient by patient basis. The clinician is required to make the diagnosis and treatment plan before ordering the appliance. Two clinical cases are described with the aim to present the advantages of this technique.

Arthroscopic Talar Dome Access Using a Standard Versus Wire-Based Traction Method for Ankle Joint Distraction.

PubMed

Barg, Alexej; Saltzman, Charles L; Beals, Timothy C; Bachus, Kent N; Blankenhorn, Brad D; Nickisch, Florian

2016-07-01

To evaluate the accessibility of the talar dome through anterior and posterior portals for ankle arthroscopy with the standard noninvasive distraction versus wire-based longitudinal distraction using a tensioned wire placed transversely through the calcaneal tuberosity. Seven matched pairs of thigh-to-foot specimens underwent ankle arthroscopy with 1 of 2 methods of distraction: a standard noninvasive strapping technique or a calcaneal tuberosity wire-based technique. The order of the arthroscopic approach and use of a distraction method was randomly determined. The areas accessed from both 2-portal anterior and 2-portal posterior approaches were determined by using a molded translucent grid. The mean talar surface accessible by anterior ankle arthroscopy was comparable with noninvasive versus calcaneal wire distraction with 57.8% ± 17.2% (range, 32.9% to 75.7%) versus 61.5% ± 15.2% (range, 38.5% to 79.1%) of the talar dome, respectively (P = .590). The use of calcaneal wire distraction significantly improved posterior talar dome accessibility compared with noninvasive distraction, with 56.4% ± 20.0% (range, 14.4% to 78.0%) versus 39.8% ± 14.9% (range, 20.0% to 57.6%) of the talar dome, respectively (P = .031). Under the conditions studied, our cadaveric model showed equivalent talar dome access with 2-portal anterior arthroscopy of calcaneal wire-based distraction versus noninvasive strap distraction, but improved access for 2-portal posterior arthroscopy with calcaneal wire-based distraction versus noninvasive strap distraction. The posterior 40% of the talar dome is difficult to access via anterior ankle arthroscopy. Posterior calcaneal tuberosity wire-based longitudinal distraction improved arthroscopic access to the centro-posterior talar dome with a posterior arthroscopic approach. Published by Elsevier Inc.

Charge transport in molecular junctions: From tunneling to hopping with the probe technique

NASA Astrophysics Data System (ADS)

Kilgour, Michael; Segal, Dvira

2015-07-01

We demonstrate that a simple phenomenological approach can be used to simulate electronic conduction in molecular wires under thermal effects induced by the surrounding environment. This "Landauer-Büttiker's probe technique" can properly replicate different transport mechanisms, phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction. Specifically, our simulations with the probe method recover the following central characteristics of charge transfer in molecular wires: (i) the electrical conductance of short wires falls off exponentially with molecular length, a manifestation of the tunneling (superexchange) mechanism. Hopping dynamics overtakes superexchange in long wires demonstrating an ohmic-like behavior. (ii) In off-resonance situations, weak dephasing effects facilitate charge transfer, but under large dephasing, the electrical conductance is suppressed. (iii) At high enough temperatures, kBT/ɛB > 1/25, with ɛB as the molecular-barrier height, the current is enhanced by a thermal activation (Arrhenius) factor. However, this enhancement takes place for both coherent and incoherent electrons and it does not readily indicate on the underlying mechanism. (iv) At finite-bias, dephasing effects may impede conduction in resonant situations. We further show that memory (non-Markovian) effects can be implemented within the Landauer-Büttiker's probe technique to model the interaction of electrons with a structured environment. Finally, we examine experimental results of electron transfer in conjugated molecular wires and show that our computational approach can reasonably reproduce reported values to provide mechanistic information.

[Three-dimensional finite element analysis of maxillary anterior teeth retraction force system in light wire technique].

PubMed

Zhang, Xiangfeng; Wang, Chao; Xia, Xi; Deng, Feng; Zhang, Yi

2015-06-01

This study aims to construct a three-dimensional finite element model of a maxillary anterior teeth retraction force system in light wire technique and to investigate the difference of hydrostatic pressure and initial displacement of upper anterior teeth under different torque values of tip back bend. A geometric three-dimensional model of the maxillary bone, including all the upper teeth, was achieved via CT scan. To construct the force model system, lingual brackets and wire were constructed by using the Solidworks. Brackets software, and wire were assembled to the teeth. ANASYS was used to calculate the hydrostatic pressure and the initial displacement of maxillary anterior teeth under different tip-back bend moments of 15, 30, 45, 60, and 75 Nmm when the class II elastic force was 0.556 N. Hydrostatic pressure was concentrated in the root apices and cervical margin of upper anterior teeth. Distal tipping and relative intrusive displacement were observed. The hydrostatic pressure and initial displacement of upper canine were greater than in the central and lateral incisors. This hydrostatic pressure and initial intrusive displacement increased with an increase in tip-back bend moment. Lingual retraction force system of maxillary anterior teeth in light wire technique can be applied safely and controllably. The type and quantity of teeth movement can be controlled by the alteration of tip-back bend moment.

[Application of rafting K-wire technique for tibial plateau fractures].

PubMed

Zhang, Xing-zhou; Yu, Wei-zhong; Li, Yun-feng; Liu, Yan-hui

2015-12-01

To summarize application of rafting K-wires technique for tibial plateau fractures. From January 2013 to January 2015,45 patients with tibial plateau fractures were treated by locking plate with rafting K-wires, including 33 males and 12 females with an average of 44.2 years old ranging from 22 to 56 years old. According to Schatzker classification, 6 cases were type II, 8 were type Ill, 4 were type IV, 4 were type V, and 5 were type VI. Allogeneic bone graft were performed for bone defects. All patients were fixed with two to five K-wires. Part of weight loading were encouraged at 3 months after operation,and full weight-loading were done at 5 months after operation. Postoperative complications were observed,and Rasmussen clinical and radiological assessment were used to evaluate clinical results. All Patients were followed up from 10 to 23 months with average of 14 months. According to Rasmussen clinical and radiological assessment, clinical scores 23.58 ± 6.33, radiological scores were 14.00 ± 6.33; and excellent and good rates were 82.2% and 77.8% respectively. Four patients occurred severe osteoporosis and collapse of articular surface; 5 patients occurred traumatic arthritis. Rafting K-wires technique with anatomized armor plate could effective fix and support platform collapse and joint bone fragments, increase support surface area and reduce postoperative reduction loss rate.

Novel experience of laser-assisted 'inside-out' central venous access in a patient with bilateral subclavian vein occlusion requiring pacemaker implantation.

PubMed

Aye, Thandar; Phan, Thanh Trung; Muir, Douglas Findlay; Linker, Nicholas John; Hartley, Richard; Turley, Andrew John

2017-10-01

This new laser facilitated 'inside-out' technique was used for transvenous pacemaker insertion in a pacemaker-dependent patient with bilateral subclavian occlusion and a failed epicardial system who is not suitable for a transfemoral approach. Procedure was undertaken under general anaesthesia with venous access obtained from right femoral vein and left axillary vein. 7F multipurpose catheter was used to enter proximal edge of the occluded segment of subclavian vein via femoral approach, which then supported stiff angioplasty wires and microcatheters to tunnel into the body of occlusion. When encountered with impenetrable resistance, 1.4 mm Excimer laser helped delivery of a Pilot 200 wire, which then progressed towards the distal edge of occlusion. Serial balloon dilatations allowed wire tracked into subintimal plane, advanced towards left clavicle using knuckle wire technique, which was then externalized with blunt dissection from infraclavicular pocket area. It was later changed to Amplatz superstiff wire exiting from both ends to form a rail, which ultimately allowed passage of pacing leads after serial balloon dilatation from clavicular end. Our hybrid 'inside-out' technique permitted transvenous pacemaker insertion without complication and this is, to our knowledge, the first case using laser in this context. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Easy route to superhydrophobic copper-based wire-guided droplet microfluidic systems.

PubMed

Mumm, Florian; van Helvoort, Antonius T J; Sikorski, Pawel

2009-09-22

Droplet-based microfluidic systems are an expansion of the lab on a chip concept toward flexible, reconfigurable setups based on the modification and analysis of individual droplets. Superhydrophobic surfaces are one suitable candidate for the realization of droplet-based microfluidic systems as the high mobility of aqueous liquids on such surfaces offers possibilities to use novel or more efficient approaches to droplet movement. Here, copper-based superhydrophobic surfaces were produced either by the etching of polycrystalline copper samples along the grain boundaries using etchants common in the microelectronics industry, by electrodeposition of copper films with subsequent nanowire decoration based on thermal oxidization, or by a combination of both. The surfaces could be easily hydrophobized with thiol-modified fluorocarbons, after which the produced surfaces showed a water contact angle as high as 171 degrees +/- 2 degrees . As copper was chosen as the base material, established patterning techniques adopted from printed circuit board fabrication could be used to fabricate macrostructures on the surfaces with the intention to confine the droplets and, thus, to reduce the system's sensitivity to tilting and vibrations. A simple droplet-based microfluidic chip with inlets, outlets, sample storage, and mixing areas was produced. Wire guidance, a relatively new actuation method applicable to aqueous liquids on superhydrophobic surfaces, was applied to move the droplets.

Review of Slow-Wave Structures

NASA Technical Reports Server (NTRS)

Wallett, Thomas M.; Qureshi, A. Haq

1994-01-01

The majority of recent theoretical and experimental reports published in the literature dealing with helical slow-wave structures focus on the dispersion characteristics and their effects due to the finite helix wire thickness and attenuation, dielectric loading, metal loading, and the introduction of plasma. In many papers, an effective dielectric constant is used to take into account helix wire dimensions and conductivity losses, while the propagation constant of the signal and the interaction impedance of the structure are found to depend on the surface resistivity of the helix. Also, various dielectric supporting rods are simulated by one or several uniform cylinders having an effective dielectric constant, while metal vane loading and plasma effects are incorporated in the effective dielectric constant. The papers dealing with coupled cavities and folded or loaded wave guides describe equivalent circuit models, efficiency enhancement, and the prediction of instabilities for these structures. Equivalent circuit models of various structures are found using computer software programs SUPERFISH and TOUCHSTONE. Efficiency enhancement in tubes is achieved through dynamic velocity and phase adjusted tapers using computer techniques. The stability threshold of unwanted antisymmetric and higher order modes is predicted using SOS and MAGIC codes and the dependence of higher order modes on beam conductance, section length, and effective Q of a cavity is shown.

Development of termination and utilization concepts for flat conductor cables. Volume 3: Cost study comparison, flat versus round conductor cable

NASA Technical Reports Server (NTRS)

1972-01-01

A cost study comparing flat conductor cable (FCC) with small-gage wire (SGW) and conventional round conductor cable (RCC) is presented. This study was based on a vehicle wiring system consisting of 110,000 ft of conventional RCC equally divided between AWG sizes 20,22, and 24 using MIL-W-81044-type wire and MIL-C-26500 circular connectors. Basic cost data were developed on a similar-sized commercial jet airplane wiring system on a previous company R&D program in which advanced wiring techniques were carried through equivalent installations on an airplane mockup; and on data developed on typical average bundles during this program. Various cost elements included were engineering labor, operations (manufacturing) labor, material costs, and cost impact on payload. Engineering labor includes design, wiring system integration, wiring diagrams and cable assembly drawings, wire installations, and other related supporting functions such as the electronic data processing for the wiring. Operations labor includes mockup, tooling and production planning, fabrication, assembly, installation, and quality control cost impact on payload is the conversion of wiring system weight variations through use of different wiring concepts to program payload benefits in terms of dollars.

Investigation of factors affecting the heater wire method of calibrating fine wire thermocouples

NASA Technical Reports Server (NTRS)

Keshock, E. G.

1972-01-01

An analytical investigation was made of a transient method of calibrating fine wire thermocouples. The system consisted of a 10 mil diameter standard thermocouple (Pt, Pt-13% Rh) and an 0.8 mil diameter chromel-alumel thermocouple attached to a 20 mil diameter electrically heated platinum wire. The calibration procedure consisted of electrically heating the wire to approximately 2500 F within about a seven-second period in an environment approximating atmospheric conditions at 120,000 feet. Rapid periodic readout of the standard and fine wire thermocouple signals permitted a comparison of the two temperature indications. An analysis was performed which indicated that the temperature distortion at the heater wire produced by the thermocouple junctions appears to be of negligible magnitude. Consequently, the calibration technique appears to be basically sound, although several practical changes which appear desirable are presented and discussed. Additional investigation is warranted to evaluate radiation effects and transient response characteristics.

Present status of PIT round wires of 122-type iron-based superconductors

NASA Astrophysics Data System (ADS)

Tamegai, T.; Suwa, T.; Pyon, S.; Kajitani, H.; Takano, K.; Koizumi, N.; Awaji, S.; Watanabe, K.

2017-12-01

Outstanding characteristics with high T c and H c2 and small anisotropy in iron-based superconductors (IBSs) have triggered the development of superconducting wires and tapes using these novel superconductors. In this short article, developments and present status of round wires of 122-type IBSs are reviewed. By introducing hot-isostatic pressing (HIP) technique, J c in round wires of 122-type IBSs has been improved significantly. Further improvements have been realized by refining the fabrication process of the core material and introducing partial texturing of the wire core. The largest transport J c for round wires at 4.2 K at self-field and 100 kOe are 2.0x105 A/cm2 and 3.8x104 A/cm2, respectively. We also compare the J c characteristics of wires and tapes processed by HIP.

A comparison of calibration techniques for hot-wires operated in subsonic compressible slip flows

NASA Technical Reports Server (NTRS)

Jones, Gregory S.; Stainback, P. C.; Nagabushana, K. A.

1992-01-01

This paper focuses on the correlation of constant temperature anemometer voltages to velocity, density, and total temperature in the transonic slip flow regime. Three different calibration schemes were evaluated. The ultimate use of these hot-wire calibrations is to obtain fluctuations in the flow variables. Without the appropriate mean flow sensitivities of the heated wire, the measurements of these fluctuations cannot be accurately determined.

Evolution of treatment mechanics and contemporary appliance design in orthodontics: A 40-year perspective.

PubMed

McLaughlin, Richard P; Bennett, John C

2015-06-01

Until the early 1970s, successful treatment with the Begg technique and the Tweed edgewise technique required tedious wire bending. The introduction of Andrews' straight wire appliance changed that, and it was one of the most significant contributions in the history of orthodontics. The straight wire appliance significantly reduced the amount of wire bending and also brought along other options in treatment mechanics. Retraction of the canines with elastic chains and ligature wires became more common. Sliding mechanics in place of closing loops became the method of space closure for a significant number of clinicians. Edgewise force levels were initially used to close spaces; however, it was soon observed that lighter forces were more effective with sliding mechanics. Along with these changes, it became apparent that compensation in the appliance was needed, depending on the type of malocclusion and particularly with varying extraction sequences. Various appliance designs were developed to accommodate changes in mechanics and force levels. These modifications improved tooth positions at the end of treatment as long as the brackets were properly placed. These major changes in appliances, force levels, and treatment mechanics can be traced back to the work of Dr Lawrence Andrews and the straight wire appliances. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Cold-Drawn Bioabsorbable Ferrous and Ferrous Composite Wires: An Evaluation of Mechanical Strength and Fatigue Durability

NASA Astrophysics Data System (ADS)

Schaffer, Jeremy E.; Nauman, Eric A.; Stanciu, Lia A.

2012-08-01

Yield strengths exceeding 1 GPa with elastic strains exceeding 1 pct were measured in novel bioabsorbable wire materials comprising high-purity iron (Fe), manganese (Mn), magnesium (Mn), and zinc (Zn), which may enable the development of self-expandable, bioabsorbable, wire-based endovascular stents. The high strength of these materials is attributed to the fine microstructure and fiber textures achieved through cold drawing techniques. Bioabsorbable vascular stents comprising nutrient metal compositions may provide a means to overcome the limitations of polymer-based bioabsorbable stents such as excessive strut thickness and poor degradation rate control. Thin, 125- μm wires comprising combinations of ferrous alloys surrounding a relatively anodic nonferrous core were manufactured and tested using monotonic and cyclic techniques. The strength and durability properties are tested in air and in body temperature phosphate-buffered saline, and then they were compared with cold-drawn 316L stainless steel wire. The antiferromagnetic Fe35Mn-Mg composite wire exhibited more than 7 pct greater elasticity (1.12 pct vs 1.04 pct engineering strain), similar fatigue strength in air, an ultimate strength of more than 1.4 GPa, and a toughness exceeding 35 mJ/mm3 compared with 30 mJ/mm3 for 316L.

Localized states in an arbitrarily bent quantum wire (bend-imitating approach)

NASA Astrophysics Data System (ADS)

Vakhnenko, Oleksity O.

1996-02-01

The bend-imitating matching technique is proposed to simplify the quantum mechanical treatment of singly and multiply bent 2D quantum wires of constant width, arbitrary bending angles, arbitrary bending radii and arbitrary distances between the bends. The spectrum of one-electron localized states and its dependence on the bending angle and the bending radius in a singly bent wire is explicitly calculated. Doubly bent wires are shown to possess doubly split localized states. The splitting energies as a function of the distance between the bends and the bending angles and bending radii have also been obtained. A similar description of bent 3D quantum wires and bent optical fibers is expected to be possible.

Automatic circuit interrupter

NASA Technical Reports Server (NTRS)

Dwinell, W. S.

1979-01-01

In technique, voice circuits connecting crew's cabin to launch station through umbilical connector disconnect automatically unused, or deadened portion of circuits immediately after vehicle is launched, eliminating possibility that unused wiring interferes with voice communications inside vehicle or need for manual cutoff switch and its associated wiring. Technique is applied to other types of electrical actuation circuits, also launch of mapped vehicles, such as balloons, submarines, test sleds, and test chambers-all requiring assistance of ground crew.

Monorail system for percutaneous repositioning of the Greenfield vena caval filter.

PubMed

Guthaner, D F; Wyatt, J O; Mehigan, J T; Wright, A M; Breen, J F; Wexler, L

1990-09-01

The authors describe a technique for removing or repositioning a malpositioned Greenfield inferior vena caval filter. A "monorail" system was used, in which a wire was passed from the femoral vein through the apical hole in the filter and out the internal jugular vein; the wire was held taut from above and below and thus facilitated repositioning or removal of the filter. The technique was used successfully in two cases.

Evaluation Of Risk And Possible Mitigation Schemes For Previously Unidentified Hazards

NASA Technical Reports Server (NTRS)

Linzey, William; McCutchan, Micah; Traskos, Michael; Gilbrech, Richard; Cherney, Robert; Slenski, George; Thomas, Walter, III

2006-01-01

This report presents the results of arc track testing conducted to determine if such a transfer of power to un-energized wires is possible and/or likely during an arcing event, and to evaluate an array of protection schemes that may significantly reduce the possibility of such a transfer. The results of these experiments may be useful for determining the level of protection necessary to guard against spurious voltage and current being applied to safety critical circuits. It was not the purpose of these experiments to determine the probability of the initiation of an arc track event only if an initiation did occur could it cause the undesired event: an inadvertent thruster firing. The primary wire insulation used in the Orbiter is aromatic polyimide, or Kapton , a construction known to arc track under certain conditions [3]. Previous Boeing testing has shown that arc tracks can initiate in aromatic polyimide insulated 28 volts direct current (VDC) power circuits using more realistic techniques such as chafing with an aluminum blade (simulating the corner of an avionics box or lip of a wire tray), or vibration of an aluminum plate against a wire bundle [4]. Therefore, an arc initiation technique was chosen that provided a reliable and consistent technique of starting the arc and not a realistic simulation of a scenario on the vehicle. Once an arc is initiated, the current, power and propagation characteristics of the arc depend on the power source, wire gauge and insulation type, circuit protection and series resistance rather than type of initiation. The initiation method employed for these tests was applying an oil and graphite mixture to the ends of a powered twisted pair wire. The flight configuration of the heater circuits, the fuel/oxider (or ox) wire, and the RCS jet solenoid were modeled in the test configuration so that the behavior of these components during an arcing event could be studied. To determine if coil activation would occur with various protection wire schemes, 145 tests were conducted using various fuel/ox wire alternatives (shielded and unshielded) and/or different combinations of polytetrafuloroethylene (PTFE), Mystik tape and convoluted wraps to prevent unwanted coil activation. Test results were evaluated along with other pertinent data and information to develop a mitigation strategy for an inadvertent RCS firing. The SSP evaluated civilian aircraft wiring failures to search for aging trends in assessing the wire-short hazard. Appendix 2 applies Weibull statistical methods to the same data with a similar purpose.

Embolization of a spinal dural arteriovenous fistula with ethylene-vinyl alcohol copolymer (Onyx) using a dual-lumen microballoon catheter and buddy wire technique.

PubMed

Nakae, Ryuta; Nagaishi, Masaya; Hyodo, Akio; Suzuki, Kensuke

2017-01-01

N -butyl 2-cyanoacrylate (NBCA) remains the standard embolic agent for spinal dural arteriovenous fistula (SDAVF) treatment. Treatment of SDAVF with ethylene-vinyl alcohol copolymer (Onyx, ev3-Covidien, Irvine CA, USA) is currently not well established. Although several cases have reported the use of Onyx to embolize an intracranial dural arteriovenous fistula using a dual-lumen microballoon catheter, Onyx embolization of an SDAVF using a dual-lumen microballoon catheter has not been reported. We treated a 57-year-old man with an SDAVF using a dual-lumen microballoon catheter and buddy wire technique to perform transarterial Onyx embolization via the left sixth intercostal artery. Onyx embolization using a dual-lumen microballoon catheter was effective. Furthermore, the buddy wire technique was useful for providing rigid support of the microcatheter in a narrow and tortuous intercostal artery.

Embolization of a spinal dural arteriovenous fistula with ethylene-vinyl alcohol copolymer (Onyx) using a dual-lumen microballoon catheter and buddy wire technique

PubMed Central

Nakae, Ryuta; Nagaishi, Masaya; Hyodo, Akio; Suzuki, Kensuke

2017-01-01

Background: N-butyl 2-cyanoacrylate (NBCA) remains the standard embolic agent for spinal dural arteriovenous fistula (SDAVF) treatment. Treatment of SDAVF with ethylene-vinyl alcohol copolymer (Onyx, ev3-Covidien, Irvine CA, USA) is currently not well established. Although several cases have reported the use of Onyx to embolize an intracranial dural arteriovenous fistula using a dual-lumen microballoon catheter, Onyx embolization of an SDAVF using a dual-lumen microballoon catheter has not been reported. Case Description: We treated a 57-year-old man with an SDAVF using a dual-lumen microballoon catheter and buddy wire technique to perform transarterial Onyx embolization via the left sixth intercostal artery. Conclusions: Onyx embolization using a dual-lumen microballoon catheter was effective. Furthermore, the buddy wire technique was useful for providing rigid support of the microcatheter in a narrow and tortuous intercostal artery. PMID:28840070

Sleeve Push Technique: A Novel Method of Space Gaining.

PubMed

Verma, Sanjeev; Bhupali, Nameksh Raj; Gupta, Deepak Kumar; Singh, Sombir; Singh, Satinder Pal

2018-01-01

Space gaining is frequently required in orthodontics. Multiple loops were initially used for space gaining and alignment. The most common used mechanics for space gaining is the use of nickel-titanium open coil springs. The disadvantage of nickel-titanium coil spring is that they cannot be used until the arches are well aligned to receive the stiffer stainless steel wires. Therefore, a new method of gaining space during initial alignment and leveling has been developed and named as sleeve push technique (SPT). The nickel-titanium wires, i.e. 0.012 inches and 0.014 inches along with archwire sleeve (protective tubing) can be used in a modified way to gain space along with alignment. This method helps in gaining space right from day 1 of treatment. The archwire sleeve and nickel-titanium wire in this new SPT act as a mutually synergistic combination and provide the orthodontist with a completely new technique for space opening.

IEEE 1988 International Symposium on Electromagnetic Compatibility, Seattle, WA, Aug. 2-4, 1988, Record

NASA Astrophysics Data System (ADS)

Various papers on electromagnetic compatibility are presented. Some of the optics considered include: field-to-wire coupling 1 to 18 GHz, SHF/EHF field-to-wire coupling model, numerical method for the analysis of coupling to thin wire structures, spread-spectrum system with an adaptive array for combating interference, technique to select the optimum modulation indices for suppression of undesired signals for simultaneous range and data operations, development of a MHz RF leak detector technique for aircraft harness surveillance, and performance of standard aperture shielding techniques at microwave frequncies. Also discussed are: spectrum efficiency of spread-spectrum systems, control of power supply ripple produced sidebands in microwave transistor amplifiers, an intership SATCOM versus radar electromagnetic interference prediction model, considerations in the design of a broadband E-field sensing system, unique bonding methods for spacecraft, and review of EMC practice for launch vehicle systems.

2D projection-based software application for mobile C-arms optimises wire placement in the proximal femur - An experimental study.

PubMed

Swartman, B; Frere, D; Wei, W; Schnetzke, M; Beisemann, N; Keil, H; Franke, J; Grützner, P A; Vetter, S Y

2017-10-01

A new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised. The software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded. Compared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method. The study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine. Copyright © 2017 Elsevier Ltd. All rights reserved.

VATS intraoperative tattooing to facilitate solitary pulmonary nodule resection.

PubMed

Willekes, Lourens; Boutros, Cherif; Goldfarb, Michael A

2008-03-19

Video-assisted thoracic surgery (VATS) has become routine and widely accepted for the removal of solitary pulmonary nodules of unknown etiology. Thoracosopic techniques continue to evolve with better instruments, robotic applications, and increased patient acceptance and awareness. Several techniques have been described to localize peripheral pulmonary nodules, including pre-operative CT-guided tattooing with methylene blue, CT scan guided spiral/hook wire placement, and transthoracic ultrasound. As pulmonary surgeons well know, the lung and visceral pleura may appear featureless on top of a pulmonary nodule. This paper presents a rapid, direct and inexpensive approach to peripheral lung lesion resection by marking the lung parenchyma on top of the nodule using direct methylene blue injection. In two patients with peripherally located lung nodules (n = 3) scheduled for VATS, we used direct methylene blue injection for intraoperative localization of the pulmonary nodule. Our technique was the following: After finger palpation of the lung, a spinal 25 gauge needle was inserted through an existing port and 0.1 ml of methylene blue was used to tattoo the pleura perpendicular to the localized nodule. The methylene blue tattoo immediately marks the lung surface over the nodule. The surgeon avoids repeated finger palpation, while lining up stapler, graspers and camera, because of the visible tattoo. Our technique eliminates regrasping and repalpating the lung once again to identify a non marked lesion. Three lung nodules were resected in two patients. Once each lesion was palpated it was marked, and the area was resected with security of accurate localization. All lung nodules were resected in totality with normal lung parenchymal margins. Our technique added about one minute to the operative time. The two patients were discharged home on the second postoperative day, with no morbidity. VATS with intraoperative tattooing is a safe, easy, and accurate technique to streamline and efficiently resect solitary pulmonary nodules.

Deformable 3D-2D registration for guiding K-wire placement in pelvic trauma surgery

NASA Astrophysics Data System (ADS)

Goerres, J.; Jacobson, M.; Uneri, A.; de Silva, T.; Ketcha, M.; Reaungamornrat, S.; Vogt, S.; Kleinszig, G.; Wolinsky, J.-P.; Osgood, G.; Siewerdsen, J. H.

2017-03-01

Pelvic Kirschner wire (K-wire) insertion is a challenging surgical task requiring interpretation of complex 3D anatomical shape from 2D projections (fluoroscopy) and delivery of device trajectories within fairly narrow bone corridors in proximity to adjacent nerves and vessels. Over long trajectories ( 10-25 cm), K-wires tend to curve (deform), making conventional rigid navigation inaccurate at the tip location. A system is presented that provides accurate 3D localization and guidance of rigid or deformable surgical devices ("components" - e.g., K-wires) based on 3D-2D registration. The patient is registered to a preoperative CT image by virtually projecting digitally reconstructed radiographs (DRRs) and matching to two or more intraoperative x-ray projections. The K-wire is localized using an analogous procedure matching DRRs of a deformably parametrized model for the device component (deformable known-component registration, or dKC-Reg). A cadaver study was performed in which a K-wire trajectory was delivered in the pelvis. The system demonstrated target registration error (TRE) of 2.1 ± 0.3 mm in location of the K-wire tip (median ± interquartile range, IQR) and 0.8 ± 1.4º in orientation at the tip (median ± IQR), providing functionality analogous to surgical tracking / navigation using imaging systems already in the surgical arsenal without reliance on a surgical tracker. The method offers quantitative 3D guidance using images (e.g., inlet / outlet views) already acquired in the standard of care, potentially extending the advantages of navigation to broader utilization in trauma surgery to improve surgical precision and safety.

Recanalization strategy for chronic total occlusions with tapered and stiff-tip guidewire. The results of CTO new techniQUE for STandard procedure (CONQUEST) trial.

PubMed

Mitsudo, Kazuaki; Yamashita, Takehiro; Asakura, Yasushi; Muramatsu, Toshiya; Doi, Osamu; Shibata, Yoshisato; Morino, Yoshihiro

2008-11-01

The success rate of percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO) lesions varies depending on the guidewire manipulation skills of the operator. The standardization of guidewire technique is very important. A new technique with a new tapered wire (Conquest, Confianza Pro) was tested to verify effectiveness for higher initial success rates and standardization of PCI for CTO. A prospective, multicenter registry was conducted at 6 investigational sites. In the CONQUEST trial, The CTO lesions were treated by using an intermediate guidewire to cross the lesion. If it did not cross, the guidewire was changed to the Conquest guidewire. If it did not cross, "seesaw-wiring" or the "parallel-wire technique" was performed. The primary endpoint was the initial procedural success rate. A total of 110 patients representing 116 CTO lesions were treated from July 2003 through March 2004. The procedural success rate was 86.2% on the first try, and 88.8% on the second try, respectively. The guidewire success rate on the second try was 90.5% during the hospital stay; no deaths, or acute myocardial infarctions were confirmed. Two patients deteriorated into tamponade, and surgical or percutaneous drainage was performed in each patient without any sequelae. A guidewire technique in PCI for CTOs that starts with the intermediate guidewire and moves to the Confianza Pro tapered guidewire, either alone or by performing a see-saw or parallel-wire technique, can achieve a high initial success rate with an acceptably low major complication rate.

Breast surgery techniques: preoperative bracketing wire localization by surgeons.

PubMed

Burkholder, Hans C; Witherspoon, Laura E; Burns, R Phillip; Horn, Jeffrey S; Biderman, Michael D

2007-06-01

With the development of expertise in image guidance for breast surgery, many surgeons now perform preoperative wire localization themselves. Use of a single wire versus multiple wires to bracket a radiographic breast abnormality has previously been described, although benefits of this technique based on clinical outcomes such as margin status, tissue volume removed, and re-excision rates have not been established. This study is a retrospective analysis of wire-localized breast biopsies performed by 14 surgeons over 29 months; stereotactic and ultrasound guidance were used. During this time, 489 wire localizations were done, of which 159 used multiple wires. Two hundred eleven of these biopsies were done for malignant disease, 86 using multiple wires. After controlling for tumor node metastases stage, single and multiple wire placements were compared using endpoints of margin status, need for re-excision, and total volume of tissue removed. Neither margin status nor re-excision was related to the number of wires placed. However, the number of wires placed was significantly related to the total volume of tissue removed. Use of more than one localizing wire was associated with greater volume of tissue removal (measured in centimeters cubed) in benign disease (46 vs 25, P < 0.001), equivalent volumes in stage 0 disease (73 vs 67), less volume in stage 1 disease (113 vs 164), and less volume in stages 2 through 4 (158 vs 207, P = 0.03). Outcomes based on surgeon case volume during the study period demonstrated that low- (1-40), medium- (41-80), and high-volume (>80) surgeons did not differ in the type or stage of breast pathology treated. Surgeons with high case volumes were more likely to place multiple localizing wires (P < 0.001) and were more likely to do a breast-conserving procedure if re-excision was performed (P < 0.018). Surgeons with low case volumes were more likely to perform a re-excision (P < 0.025). Surgeon experience has a positive impact on quality outcome measures such as performance of a definitive procedure at the time of initial surgery and use of breast-conserving procedures at the time of re-excision. Multiple wire localization can be used to significantly reduce the volume of breast tissue removed in malignant disease without sacrificing margin status or increasing the need for future re-excision.

Intraoperative Ultrasound for Peripheral Nerve Applications.

PubMed

Willsey, Matthew; Wilson, Thomas J; Henning, Phillip Troy; Yang, Lynda J-S

2017-10-01

Offering real-time, high-resolution images via intraoperative ultrasound is advantageous for a variety of peripheral nerve applications. To highlight the advantages of ultrasound, its extraoperative uses are reviewed. The current intraoperative uses, including nerve localization, real-time evaluation of peripheral nerve tumors, and implantation of leads for peripheral nerve stimulation, are reviewed. Although intraoperative peripheral nerve localization has been performed previously using guide wires and surgical dyes, the authors' approach using ultrasound-guided instrument clamps helps guide surgical dissection to the target nerve, which could lead to more timely operations and shorter incisions. Copyright © 2017 Elsevier Inc. All rights reserved.

Cuff inflation-supplemented laryngoscope-guided nasal intubation: a comparison of three endotracheal tubes.

PubMed

Kumar, Rakesh; Gupta, Ekta; Kumar, Sunil; Rani Sharma, Kavita; Rani Gupta, Neera

2013-03-01

Softer endotracheal (ET) tubes are more difficult to navigate in the oropharynx than the stiffer polyvinyl chloride (PVC) tubes during nasotracheal intubation (NTI). Cuff inflation has been used to guide PVC tubes into the laryngeal inlet during blind NTI, but it has not been tested when performing NTI under direct laryngoscopic guidance. We assessed the role of cuff inflation in improving oropharyngeal navigation of 3 ET tubes of varying stiffness during direct laryngoscope-guided NTI. Simultaneously, we also assessed and compared the nasotracheal navigability and incidence of nasal injury with these ET tubes during cuff inflation-supplemented, laryngoscope-guided NTI. One hundred sixty-two adults were randomized to undergo NTI with either a conventional PVC (n = 54), wire reinforced (WR; n = 54) or a silicone-tipped WR (SWR; n = 54) ET tube. Ease of insertion of these tubes was assessed during passage from nose into oropharynx, from oropharynx into laryngeal inlet aided by cuff inflation if needed, and from laryngeal inlet into trachea. Nasal morbidity was assessed by a blinded observer. All ET tubes could be inserted into the trachea. Seventy-one of 162 ET tubes could be inserted from the oropharynx into the laryngeal inlet without cuff inflation. Eighty-six of the remaining 91 tubes that did not enter the laryngeal inlet without cuff inflation could be inserted when using the cuff inflation technique. Thus, a total of 157 ET tubes could be inserted into the laryngeal inlet with cuff inflation (95% confidence interval of difference of proportions between total number of tubes passed [157] and those without cuff inflation [71]: 53% [45%-61%]). The remaining 5 tubes had to be inserted with the help of Magill forceps. The incidence of epistaxis was lowest with the SWR tube (difference of proportions [95% confidence interval] SWR versus PVC 27% [8%-45%]; SWR versus WR 20% [1%-38%]; WR versus PVC 7% [-12% to 26%]). The cuff inflation technique consistently improved the oropharyngeal insertion of the 3 ET tubes of varying stiffness during direct laryngoscope-guided NTI. Supplemented with the cuff inflation technique, the SWR ET tube seems to be better than the PVC and WR ET tubes in terms of complete nasotracheal navigability and less perioperative nasal injury.

Simple and fast orotracheal intubation procedure in rats.

PubMed

Tomasello, Giovanni; Damiani, Francesco; Cassata, Giovanni; Palumbo, Vincenzo Davide; Sinagra, Emanuele; Damiani, Provvidenza; Bruno, Antonino; Cicero, Luca; Cupido, Francesco; Carini, Francesco; Lo Monte, Attilio Ignazio

2016-05-06

Endotracheal intubation in the rat is difficult because of the extremely small size of anatomical structures (oral cavity, epiglottis and vocal cords), small inlet for an endotracheal tube and the lack of proper technical instruments. In this study we used seventy rats weighting 400-500 g. The equipment needed for the intubation was an operating table, a longish of cotton, a cotton tip, orotracheal tube, neonatal laryngoscope blades, KTR4 small animal ventilator and isoflurane for inhalation anaesthesia. Premedication was carried out by medetomidine hydrochloride 1 mg/mL; then, thanks to a closed glass chamber, a mixture of oxygen and isoflurane was administered. By means of a neonatal laryngoscope the orotracheal tube was advanced into the oral cavity until the wire guide was visualized trough the vocal cords; then it was passed through them. The tube was introduced directly into the larynx over the wire guide; successively, the guide was removed and the tube placed into the trachea. Breathing was confirmed using a glove, cut at the end of a finger, simulating a small balloon. We achieved a fast and simple orotracheal intubation in all animals employed. We believe that our procedure is easier and faster than those previously reported in scientific literature.

Modified tension band wiring fixation for avulsion fractures of the calcaneus in osteoporotic bone: a review of three patients.

PubMed

Nagura, Issei; Fujioka, Hiroyuki; Kurosaka, Masahiro; Mori, Hiroyuki; Mitani, Makoto; Ozaki, Akihiro; Fujii, Hideo; Nabeshima, Yuji

2012-01-01

Calcaneal avulsion fractures are not uncommon, and they are probably more likely in patients with osteoporosis. Closed manipulation for this type of fracture often fails to achieve acceptable reduction, and open reduction and internal fixation are usually required. However, open reduction and internal fixation with either a lag screw or Steinmann pins do not provide satisfactory fixation in patients with diabetes and elderly patients because of the presence of porotic bone. Levi described a tension band fixation system used to treat a calcaneal avulsion fracture using a simple technique performed with a transverse Kirschner wire through the os calcaneus, securing a figure-of-8 metal tension band wiring to the fragment. We report the successful treatment of 3 patients with calcaneal avulsion fractures using a modified tension band wiring technique, resulting in satisfactory recovery. Re-displacement of the fragment during the initial follow-up period was not reported, and bony union was achieved in all patients. We believe this technique is a useful surgical option for the treatment of calcaneal avulsion fractures. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Far infrared polarizing grids for use at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Novak, Giles; Sundwall, Jeffrey L.; Pernic, Robert J.

1989-01-01

A technique is proposed for the construction of free-standing wire grids for use as far-IR polarizers. The method involves wrapping a strand of wire around a single cylinder rather than around a pair of parallel rods, thus simplifying the problem of maintaining constant wire tension. The cylinder is composed of three separate pieces which are disassembled at a later stage in the grid-making process. Grids have been constructed using 8-micron-diameter stainless steel wire and a grid spacing of 25 microns. The grids are shown to be reliable under repeated cycling between room temperature and 1.5 K.

Two dimensional exciton polaritons in microcavities with embedded quantum wires

NASA Astrophysics Data System (ADS)

Kavokin, A. V.; Ivchenko, E. L.; Vladimirova, M. R.; Kaliteevski, M. A.; Goupalov, S. V.

1998-02-01

Optical anisotropy of the periodical array of quantum wires embedded in a semiconductor microcavity is shown to result in polarization-dependent vacuum-field Rabi-splitting and a triple-anticrossing shape of the exciton-polariton dispersion curves. Both effects originate from the resonant diffraction of light at the grating of quantum wires. The calculation has been done within the nonlocal dielectric response theory and using the 4 × 4 transfer matrix technique.

Manufacturing and quality control of interconnecting wire harnesses, Volume 2

NASA Technical Reports Server (NTRS)

1972-01-01

Interconnecting wire harnesses defined in the design standard are considered, including type 4, open bundle (not enclosed). Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into the document.

Proposal for a new trajectory for subaxial cervical lateral mass screws.

PubMed

Amhaz-Escanlar, Samer; Jorge-Mora, Alberto; Jorge-Mora, Teresa; Febrero-Bande, Manuel; Diez-Ulloa, Maximo-Alberto

2018-06-20

Lateral mass screws combined with rods are the standard method for posterior cervical spine subaxial fixation. Several techniques have been described, among which the most used are Roy Camille, Magerl, Anderson and An. All of them are based on tridimensional angles. Reliability of freehand angle estimation remains poorly investigated. We propose a new technique based on on-site spatial references and compare it with previously described ones assessing screw length and neurovascular potential complications. Four different lateral mass screw insertion techniques (Magerl, Anderson, An and the new described technique) were performed bilaterally, from C3 to C6, in ten human spine specimens. A drill tip guide wire was inserted as originally described for each trajectory, and screw length was measured. Exit point was examined, and potential vertebral artery or nerve root injury was assessed. Mean screw length was 14.05 mm using Magerl's technique, 13.47 mm using Anderson's, 12.8 mm using An's and 17.03 mm using the new technique. Data analysis showed significantly longer lateral mass screw length using the new technique (p value < 0.00001). Nerve potential injury occurred 37 times using Magerl's technique, 28 using Anderson's, 13 using An's and twice using the new technique. Vertebral artery potential injury occurred once using Magerl's technique, 8 times using Anderson's and none using either An's or the new proposed technique. The risk of neurovascular complication was significantly lower using the new technique (p value < 0.01). The new proposed technique allows for longer screws, maximizing purchase and stability, while lowering the complication rate.

Analysis of pilot control strategy

NASA Technical Reports Server (NTRS)

Heffley, R. K.; Hanson, G. D.; Jewell, W. F.; Clement, W. F.

1983-01-01

Methods for nonintrusive identification of pilot control strategy and task execution dynamics are presented along with examples based on flight data. The specific analysis technique is Nonintrusive Parameter Identification Procedure (NIPIP), which is described in a companion user's guide (NASA CR-170398). Quantification of pilot control strategy and task execution dynamics is discussed in general terms followed by a more detailed description of how NIPIP can be applied. The examples are based on flight data obtained from the NASA F-8 digital fly by wire airplane. These examples involve various piloting tasks and control axes as well as a demonstration of how the dynamics of the aircraft itself are identified using NIPIP. Application of NIPIP to the AFTI/F-16 flight test program is discussed. Recommendations are made for flight test applications in general and refinement of NIPIP to include interactive computer graphics.

Distributed temperature sensing using a SPIRAL configuration ultrasonic waveguide

NASA Astrophysics Data System (ADS)

Periyannan, Suresh; Balasubramaniam, Krishnan

2017-02-01

Distributed temperature sensing has important applications in the long term monitoring of critical enclosures such as containment vessels, flue gas stacks, furnaces, underground storage tanks and buildings for fire risk. This paper presents novel techniques for such measurements, using wire in a spiral configuration and having special embodiments such a notch for obtaining wave reflections from desired locations. Transduction is performed using commercially available Piezo-electric crystal that is bonded to one end of the waveguide. Lower order axisymmetric guided ultrasonic modes were employed. Time of fight (TOF) differences between predefined reflectors located on the waveguides are used to infer temperature profile in a chamber with different temperatures. The L(0,1) wave mode (pulse echo approach) was generated/received in a spiral waveguide at different temperatures for this work. The ultrasonic measurements were compared with commercially available thermocouples.

In vitro biomechanical comparison of multistrand cables with conventional cervical stabilization.

PubMed

Weis, J C; Cunningham, B W; Kanayama, M; Parker, L; McAfee, P C

1996-09-15

The biomechanical stability of six different methods of cervical spine stabilization, three using multistrand cables, were evaluated in a bovine model. To quantify and compare the in vitro biomechanical properties of multistrand cables used for posterior cervical wiring to standard cervical fixation techniques. Fixation of the posterior cervical spine with monofilament stainless steel wire is a proven technique for stabilization of the cervical spine. Recently, multistrand braided cables have been used as a substitute for monofilament stainless steel wires. These cables, made of stainless steel, titanium, or polyethylene, are reported to be stronger, more flexible, and fatigue resistant than are monofilament wire based on mechanical testing. However, no in vitro biomechanical studies have been performed testing a standard posterior cervical wiring technique using multistrand cables. Thirty-six fresh frozen cervical calf spines consistent in size and age were mounted and fixed rigidly to isolate the C4-C5 motion segment. Six different reconstruction techniques were evaluated for Rogers' posterior cervical wiring technique using: 1) 20-gauge stainless steel monofilament wire, 2) stainless steel cable, 3) titanium cable, 4) polyethylene cables, 5) anterior locking plate construct with interbody graft, and 6) posterior plate construct. Six cervical spines were included in each group (n = 6), with each specimen statically evaluated under three stability conditions: 1) intact, 2) reconstructed, and 3) postfatigue. The instability model created before the reconstruction consisted of a distractive flexion Stage 3 injury at C4-C5. Nondestructive static biomechanical testing, performed on an material testing machine (MTS 858 Bionix test system, Minneapolis, MN), included axial compression, axial rotation, flexion-extension, and lateral bending. After reconstruction and static analysis, the specimens were fatigued for 1500 cycles and then statically retested. Data analysis included normalization of the reconstructed and postfatigue data to the intact condition. The calculated static parameters included operative functional unit stiffness and range of motion. Posterior cervical reconstruction with stainless steel monofilament wire proved inadequate under fatigue testing. Two of the six specimens failed with fatigue, and this construct permitted the greatest degree of flexion-extension motion after fatigue in comparison with all other constructs (P < 0.05). There were no significant differences in flexural stiffness or range of motion between stainless steel, titanium, or polyethylene cable constructs before or after fatigue testing. The posterior cervical plate constructs were the stiffest constructs under flexion, extension, and lateral bending modes, before and after fatigue testing (P < 0.05). Multistrand cables were superior to monofilament wire with fatigue testing using an in vitro calf cervical spine model. There were no failures or detectable differences in elongation after fatigue testing between the stainless steel, titanium, and polyethylene cables, as shown by the flexion-extension range of motion. The posterior cervical plate construct offered the greatest stability compared with all other constructs.

Practical aspects of instrumentation system installation, volume 13

NASA Technical Reports Server (NTRS)

Borek, R. W.; Pool, A. (Editor); Sanderson, K. C. (Editor)

1981-01-01

A review of factors influencing installation of aircraft flight test instrumentation is presented. Requirements, including such factors as environment, reliability, maintainability, and system safety are discussed. The assessment of the mission profile is followed by an overview of electrical and mechanical installation factors with emphasis on shock/vibration isolation systems and standardization of the electric wiring installation, two factors often overlooked by instrumentation engineers. A discussion of installation hardware reviews the performance capabilities of wiring, connectors, fuses and circuit breakers, and a guide to proper selections is provided. The discussion of the installation is primarily concerned with the electrical wire routing, shield terminations and grounding. Also inclued are some examples of installation mistakes that could affect system accuracy. System verification procedures and special considerations such as sneak circuits, pyrotechnics, aircraft antenna patterns, and lightning strikes are discussed.

Transurethral ultrasonic ureterolithotripsy using a solid-wire probe.

PubMed

Chaussy, C; Fuchs, G; Kahn, R; Hunter, P; Goodfriend, R

1987-05-01

A multicenter study evaluates a new technique for transurethral ultrasonic ureterolithotripsy utilizing a solid-wire probe. The transverse vibrations of the probe cause greater stone disintegration. A small ureteroscope is used and a basket is not required. There was a 96.6 per cent success rate in 118 cases. This technique has significantly improved ultrasonic lithotripsy. It has proved to be useful for upper ureteral stones not amenable to extracorporeal shock-wave lithotripsy and lower ureteral stones including "steinstrasse."

Pull-Through Technique for Recanalization of Occluded Portosystemic Shunts (TIPS): Technical Note and Review of the Literature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Toshihiro, E-mail: toshihir@bf6.so-net.ne.jp; Guenther, Rolf W., E-mail: guenther@rad.rwth-aachen.de; Isfort, Peter, E-mail: isfort@hia.rwth-aachen.de

Transjugular intrahepatic portosystemic shunt (TIPS) dysfunction is an important problem after creation of shunts. Most commonly, TIPS recanalization is performed via the jugular vein approach. Occasionally it is difficult to cross the occlusion. We describe a hybrid technique for TIPS revision via a direct transhepatic access combined with a transjugular approach. In two cases, bare metal stents or polytetrafluoroethylene (PTFE)-covered stent grafts had been placed in TIPS tract previously, and they were completely obstructed. The tracts were inaccessible via the jugular vein route alone. In each case, after fluoroscopy or computed tomography-guided transhepatic puncture of the stented segment of themore » TIPS, a wire was threaded through the shunt and snared into the right jugular vein. The TIPS was revised by balloon angioplasty and additional in-stent placement of PTFE-covered stent grafts. The patients were discharged without any complications. Doppler sonography 6 weeks after TIPS revision confirmed patency in the TIPS tract and the disappearance of ascites. We conclude that this technique is feasible and useful, even in patients with previous PTFE-covered stent graft placement.« less

Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI).

PubMed

Kim, Y G; Song, J B; Kim, J C; Kim, J M; Yoo, B H; Yun, S B; Hwang, D Y; Lee, H G

2017-08-01

This note presents a superconducting joint technique for the development of MgB 2 magnetic resonance imaging (MRI) magnets. The MgB 2 superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was <10 -14 Ω, demonstrating that the proposed joint technique could be employed for developing "next-generation" MgB 2 MRI magnets operating in the persistent current mode.

The flying hot wire and related instrumentation

NASA Technical Reports Server (NTRS)

Coles, D.; Cantnell, B.; Wadcock, A.

1978-01-01

A flying hot-wire technique is proposed for studies of separated turbulent flow in wind tunnels. The technique avoids the problem of signal rectification in regions of high turbulence level by moving the probe rapidly through the flow on the end of a rotating arm. New problems which arise include control of effects of torque variation on rotor speed, avoidance of interference from the wake of the moving arms, and synchronization of data acquisition with rotation. Solutions for these problems are described. The self-calibrating feature of the technique is illustrated by a sample X-array calibration.

Low-Cost Intra-Articular Distraction Technique Using Kirschner Wires and a Toothed Lamina Spreader.

PubMed

Shymon, Stephen Joseph; Harris, Thomas Gregory

We describe a low-cost (instrument cost) technique for joint distraction using 2 Kirschner wires and a toothed lamina spreader in lieu of a Hintermann distractor. The described technique allows for temporary intra-articular distraction and visualization and preservation of the articular surface with extra-articular instrumentation. The technique can also allow for closed reduction and percutaneous treatment in cases of soft tissue compromise. Additionally, the technique uses common orthopedic surgical instruments, leading to a minimal learning curve for novice surgeons. We have found this distraction technique to be most effective for intra-articular preparation of hindfoot and midfoot arthrodeses and for navicular fracture reduction. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Prevention of longitudinal crack propagation around a femoral prosthesis: a study of cerclage wire fixation.

PubMed

Difazio, F A; Incavo, S J; Howe, J D

1993-09-01

This study examined the effect of single versus triple-wrap cerclage fixation techniques in preventing propagation of a longitudinal fracture around a cementless femoral prosthesis. A proximal filling femoral component was implanted in 14 matched pairs of fresh-frozen bovine femora, following placement of a 45-mm longitudinal crack in the anteromedial cortical wall of the proximal femur. In one group of seven pairs, a single cerclage wire was applied to one specimen of each pair. A triple-wrap of a single cerclage wire was similarly placed in one specimen of each of the other seven pairs. All specimens were axially loaded on a materials testing system machine and the force required to propagate the fracture of the proximal femur was recorded. A triple-wrap cerclage technique required a significant increase in the force to propagate a proximal femur fracture around a non-cemented prosthesis when compared to a single cerclage wire. Copyright © 1993. Published by Elsevier Ltd.

Offline impedance measurements for detection and mitigation of dangerous implant interactions: an RF safety prescreen.

PubMed

Ellenor, Christopher W; Stang, Pascal P; Etezadi-Amoli, Maryam; Pauly, John M; Scott, Greig C

2015-03-01

The concept of a "radiofrequency safety prescreen" is investigated, wherein dangerous interactions between radiofrequency fields used in MRI, and conductive implants in patients are detected through impedance changes in the radiofrequency coil. The behavior of coupled oscillators is reviewed, and the resulting, observable impedance changes are discussed. A birdcage coil is loaded with a static head phantom and a wire phantom with a wire close to its resonant length, the shape, position, and orientation of which can be changed. Interactions are probed with a current sensor and network analyzer. Impedance spectra show dramatic, unmistakable splitting in cases of strong coupling, and strong correlation is observed between induced current and scattering parameters. The feasibility of a new, low-power prescreening technique has been demonstrated in a simple phantom experiment, which can unambiguously detect resonant interactions between an implanted wire and an imaging coil. A new technique has also been presented which can detect parallel transmit null modes for the wire. © 2014 Wiley Periodicals, Inc.

Cast aluminium single crystals cross the threshold from bulk to size-dependent stochastic plasticity

NASA Astrophysics Data System (ADS)

Krebs, J.; Rao, S. I.; Verheyden, S.; Miko, C.; Goodall, R.; Curtin, W. A.; Mortensen, A.

2017-07-01

Metals are known to exhibit mechanical behaviour at the nanoscale different to bulk samples. This transition typically initiates at the micrometre scale, yet existing techniques to produce micrometre-sized samples often introduce artefacts that can influence deformation mechanisms. Here, we demonstrate the casting of micrometre-scale aluminium single-crystal wires by infiltration of a salt mould. Samples have millimetre lengths, smooth surfaces, a range of crystallographic orientations, and a diameter D as small as 6 μm. The wires deform in bursts, at a stress that increases with decreasing D. Bursts greater than 200 nm account for roughly 50% of wire deformation and have exponentially distributed intensities. Dislocation dynamics simulations show that single-arm sources that produce large displacement bursts halted by stochastic cross-slip and lock formation explain microcast wire behaviour. This microcasting technique may be extended to several other metals or alloys and offers the possibility of exploring mechanical behaviour spanning the micrometre scale.

Characterization and application of Shape Memory Alloy wires for micro and meso positioning systems

NASA Astrophysics Data System (ADS)

Khan, Afzal

The properties of Shape Memory Alloy (SMA) wires are determined by experimentation, and previously used experimental equipment contributes to measurement errors in data. In this study, various characterization experiments are designed and carried out using a precision characterization instrument for shape memory alloy wires to determine the properties and parameters of the alloy. These experiments demonstrate the behavior of SMA wires under different thermal and loading conditions as they occur in actuation applications. As SMA wires go through phase transformation, a significant amount of contraction force is produced. This actuation force has been used in bias spring actuators and differential actuators. In this dissertation, the force generated during the twinning of martensite is used to actuate positioning systems with small displacements at the micrometer level. A micropositioning system is designed and tested that has a positioning accuracy of about +/-0.15 mum. A relation between the current input and the displacement output is determined for the specific preload. The transformation force generated during the phase change from martensite to austenite is used as an actuation force for a second positioning system that uses linear bearing with a displacement range of about a millimeter. This positioning system actuated with a single nitinol wire and guided by symmetric parallel diaphragm flexures, was designed and tested. The actuation is repeatable to about +/-15 mum with variation of about +/-5 mum in postion at steady temperature.

The effect of ZnO nanoparticle coating on the frictional resistance between orthodontic wires and ceramic brackets

PubMed Central

Behroozian, Ahmad; Kachoei, Mojgan; Khatamian, Masumeh; Divband, Baharak

2016-01-01

Background. Any decrease in friction between orthodontic wire and bracket can accelerate tooth movement in the sliding technique and result in better control of anchorage. This study was carried out to evaluate frictional forces by coating orthodontic wires and porcelain brackets with zinc oxide nanoparticles (ZnO). Methods. In this in vitro study, we evaluated a combination of 120 samples of 0.019×0.025 stainless steel (SS) orthodonticwires and 22 mil system edgewise porcelain brackets with and without spherical zinc oxide nanoparticles. Spherical ZnOnanoparticles were deposited on wires and brackets by immersing them in ethanol solution and SEM (scanning electronmicroscope) evaluation confirmed the presence of the ZnO coating. The frictional forces were calculated between the wiresand brackets in four groups: group ZZ (coated wire and bracket), group OO (uncoated wire and bracket), group ZO (coatedwire and uncoated bracket) and group OZ (uncoated wire and coated bracket). Kolmogorov-Smirnov, Mann-Whitney andKruskal-Wallis tests were used for data analysis. Results. The frictional force in ZZ (3.07±0.4 N) was the highest (P <0.05), and OZ (2.18±0.5 N) had the lowest amount of friction (P <0.05) among the groups. There was no significant difference in frictional forces between the ZO and OO groups (2.65±0.2 and 2.70±0.2 N, respectively). Conclusion. Coating of porcelain bracket surfaces with ZnO nanoparticles can decrease friction in the sliding technique,and wire coating combined with bracket coating is not recommended due to its effect on friction. PMID:27429727

Novel devices and systems for terahertz spectroscopy and imaging

NASA Astrophysics Data System (ADS)

Wang, Kanglin

This doctoral thesis documents my research on novel devices and systems for terahertz (THz) spectroscopy and imaging. The research is particularly focused on the manipulation of THz radiation, including subwavelength concentration and low-loss wave guiding. One of the major obstacles for THz imaging is the poor spatial resolution due to the diffraction of the long-wavelength light source. To break this restriction, we build a THz near-field microscopy system by combining apertureless near-field scanning optical microscopy (ANSOM) with terahertz time-domain spectroscopy (THz-TDS). The experimental result indicates a sub-wavelength spatial resolution of about 10 micron. Abnormal frequency response of the ANSOM probe tip is observed, and a dipole antenna model is developed to explain the bandwidth reduction of the detected THz pulses. We also observe and characterize the THz wave propagation on the near-field probe in ANSOM. These studies not only demonstrate the feasibility of ANSOM in the THz frequency range, but also provide fundamental insights into the near-field microscopy in general, such as the broadband compatibility, the propagation effects and the antenna effects. Motivated by our study of the propagation effects in THz ANSOM, we characterize the guided mode of THz pulses on a bare metal wire by directly measuring the spatial profile of electric field of the mode, and find that the wire structure can be used to guide THz waves with outstanding performance. This new broadband THz waveguide exhibits very small dispersion, extremely low attenuation and remarkable structural simplicity. These features make it especially suitable for use in THz sensing and imaging systems. The first THz endoscope is demonstrated based on metal wire waveguides. To improve the input coupling efficiency of such waveguides, we develop a photoconductive antenna with radial symmetry which can generate radially polarized THz radiation matching the waveguide mode. Through THz-TDS measurements and theoretical calculations, we study the dispersion relation of the surface waves on metal wires, which indicates the increasing importance of skin effects for surface waves in the THz frequency range.

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.

A Survey of Measurements and Measuring Techniques in Rapidly Distorted Compressible Turbulent Boundary Layers

DTIC Science & Technology

1989-05-01

between the two vertically separated wires closer to the wall. This indicates that the structure becomes less coherent closer to the wall sgain explaining...bibliography prepared by Freymuth (1978), and the application of hot- wire anemometry to subsonic flows has been systematicallv researched since that time...the wire and through the prongs modifies the frequency response of the sensor . Steps in the amplitude Bode diagram can occur, similar to those arising

Development of a Miniaturized Hadamard Transform Time-of-Flight Mass Spectrometer

DTIC Science & Technology

2007-02-01

technique’s name. These pulses are generated using a Bradbury- Nielson gate (BNG), which is a set of two interleaved, electrically isolated and...interleaved sets of wire electrodes that are electrically isolated from one another and that lie in a plane perpendicular to the trajectory of the ion beam...electrical isolation of the two wire sets that are interleaved. In .the• im-ethod develioped in -th-is ab,-both- challengesar-e- overcome by-weaving wires

A Large, Free-Standing Wire Grid for Microwave Variable-delay Polarization Modulation

NASA Technical Reports Server (NTRS)

Voellmer, George

2008-01-01

One technique for mapping the polarization signature of the cosmic microwave background uses large, polarizing grids in reflection. We present the system requirements, the fabrication, assembly, and alignment procedures, and the test results for the polarizing grid component of a 50 cm clear aperture, Variable-delay Polarization Modulator (VPM). This grid is being built and tested at the Goddard Space Flight Center as part of the Polarimeter for Observing Inflationary Cosmology at the Reionization Epoch (POINCARE). VPMs modulate the polarized component of a radiation source by splitting the incoming beam into two orthogonal polarization components using a free-standing wire grid. The path length difference between these components is varied with a translating mirror, and then they are recombined. This precision instrumentation technique can be used to encode and demodulate the cosmic microwave background's polarization signature. For the demonstration instrument, 64 micrometer diameter tungsten wires are being assembled into a 200 pm pitch, free-standing wire grid with a 50 cm clear aperture, and an expected overall flatness better than 30 micrometers. A rectangular, aluminum stretching frame holds the wires with sufficient tension to achieve a minimum resonant frequency of 185 Hz, allowing VPM mirror translation frequencies of several Hz. A lightly loaded, flattening ring with a 50 cm inside diameter rests against the wires and brings them into accurate planarity.

Effect of electrical spot welding on load deflection rate of orthodontic wires.

PubMed

Alavi, Shiva; Abrishami, Arezoo

2015-01-01

One of the methods used for joining metals together is welding, which can be carried out using different techniques such as electric spot welding. This study evaluated the effect of electric spot welding on the load deflection rate of stainless steel and chromium-cobalt orthodontic wires. In this experimental-laboratory study, load deflection rate of 0.016 × 0.022 inch stainless steel and chromium cobalt wires were evaluated in five groups (n =18): group one: Stainless steel wires, group two: chromium-cobalt wires, group three: stainless steel wires welded to stainless steel wires, group four: Stainless steel wires welded to chromium-cobalt wires, group five: chromium-cobalt wire welded to chromium-cobalt wires. Afterward, the forces induced by the samples in 0.5 mm, 1 mm, 1.5 mm deflection were measured using a universal testing machine. Then mean force measured for each group was compared with other groups. The data were analyzed using repeated measure analysis of variance (ANOVA), one-way ANOVA, and paired t-test by the SPSS software. The significance level was set as 0.05. The Tukey test showed that there were significant differences between the load deflection rates of welded groups compared to control ones (P < 0.001). Considering the limitation of this study, the electric spot welding process performed on stainless steel and chromium-cobalt wires increased their load deflection rates.

Lightning induced currents in aircraft wiring using low level injection techniques

NASA Technical Reports Server (NTRS)

Stevens, E. G.; Jordan, D. T.

1991-01-01

Various techniques were studied to predict the transient current induced into aircraft wiring bundles as a result of an aircraft lightning strike. A series of aircraft measurements were carried out together with a theoretical analysis using computer modeling. These tests were applied to various aircraft and also to specially constructed cylinders installed within coaxial return conductor systems. Low level swept frequency CW (carrier waves), low level transient and high level transient injection tests were applied to the aircraft and cylinders. Measurements were made to determine the transfer function between the aircraft drive current and the resulting skin currents and currents induced on the internal wiring. The full threat lightning induced transient currents were extrapolated from the low level data using Fourier transform techniques. The aircraft and cylinders used were constructed from both metallic and CFC (carbon fiber composite) materials. The results show the pulse stretching phenomenon which occurs for CFC materials due to the diffusion of the lightning current through carbon fiber materials. Transmission Line Matrix modeling techniques were used to compare theoretical and measured currents.

Corrosion behavior and surface structure of orthodontic Ni-Ti alloy wires.

PubMed

Iijima, M; Endo, K; Ohno, H; Yonekura, Y; Mizoguchi, I

2001-03-01

The corrosion behaviors of a commercial Ni-Ti alloy orthodontic wire and a polished plate with same composition in 0.9% NaCl and 1% lactic acid solutions were examined using an electrochemical technique, an analysis of released ions, and a surface analysis by X-ray photoelectron spectroscopy (XPS). The effect of polishing the wire on the corrosion was also examined. The XPS analysis demonstrated the presence of a thick oxide film mainly composed of TiO2 with trace amounts of Ni hydroxide, which had formed on the wire surface during the heat treatment and subsequent pickling processes. This oxide layer contributed to the higher resistance of the as-received wire to both general and localized corrosion in 0.9% NaCl solution, compared with that of the polished plate and the polished wire. The thick oxide layer, however, was not stable and did not protect the orthodontic wire from corrosion in 0.1% lactic acid solution.

Improvements to Wire Bundle Thermal Modeling for Ampacity Determination

NASA Technical Reports Server (NTRS)

Rickman, Steve L.; Iannello, Christopher J.; Shariff, Khadijah

2017-01-01

Determining current carrying capacity (ampacity) of wire bundles in aerospace vehicles is critical not only to safety but also to efficient design. Published standards provide guidance on determining wire bundle ampacity but offer little flexibility for configurations where wire bundles of mixed gauges and currents are employed with varying external insulation jacket surface properties. Thermal modeling has been employed in an attempt to develop techniques to assist in ampacity determination for these complex configurations. Previous developments allowed analysis of wire bundle configurations but was constrained to configurations comprised of less than 50 elements. Additionally, for vacuum analyses, configurations with very low emittance external jackets suffered from numerical instability in the solution. A new thermal modeler is presented allowing for larger configurations and is not constrained for low bundle infrared emissivity calculations. Formulation of key internal radiation and interface conductance parameters is discussed including the effects of temperature and air pressure on wire to wire thermal conductance. Test cases comparing model-predicted ampacity and that calculated from standards documents are presented.

Safety in the Chemical Laboratory

ERIC Educational Resources Information Center

Steere, Norman V.

1969-01-01

Presents the Safety Guide used in the Research Center at Monsanto Chemical Company (St. Louis). Topics include: general safety practices, safety glasses and shoes, respiratory protection, electrical wiring, solvent handling and waste disposal. Procedures are given for evacuating, "tagging out, and "locking out. Special mention is given to…

Electronics Book III.

ERIC Educational Resources Information Center

Johnson, Dennis; And Others

This manual, the third of three curriculum guides for an electronics course, is intended for use in a program combining vocational English as a second language (VESL) with bilingual vocational education. Ten units cover AC fundamentals, circuit protection devices, low voltage circuits, communication systems, graphic illustrations, house wiring,…

A 3D virtual reality simulator for training of minimally invasive surgery.

PubMed

Mi, Shao-Hua; Hou, Zeng-Gunag; Yang, Fan; Xie, Xiao-Liang; Bian, Gui-Bin

2014-01-01

For the last decade, remarkable progress has been made in the field of cardiovascular disease treatment. However, these complex medical procedures require a combination of rich experience and technical skills. In this paper, a 3D virtual reality simulator for core skills training in minimally invasive surgery is presented. The system can generate realistic 3D vascular models segmented from patient datasets, including a beating heart, and provide a real-time computation of force and force feedback module for surgical simulation. Instruments, such as a catheter or guide wire, are represented by a multi-body mass-spring model. In addition, a realistic user interface with multiple windows and real-time 3D views are developed. Moreover, the simulator is also provided with a human-machine interaction module that gives doctors the sense of touch during the surgery training, enables them to control the motion of a virtual catheter/guide wire inside a complex vascular model. Experimental results show that the simulator is suitable for minimally invasive surgery training.

Dual-Wavelength Interferometry and Light Emission Study for Experimental Support of Dual-Wire Ablation Experiments

NASA Astrophysics Data System (ADS)

Hamilton, Andrew; Caplinger, James; Sotnikov, Vladimir; Sarkisov, Gennady; Leland, John

2017-10-01

In the Plasma Physics and Sensors Laboratory, located at Wright Patterson Air Force Base, we utilize a pulsed power source to create plasma through a wire ablation process of metallic wires. With a parallel arrangement of wires the azimuthal magnetic fields generated around each wire, along with the Ohmic current dissipation and heating occurring upon wire evaporation, launch strong radial outflows of magnetized plasmas towards the centralized stagnation region. It is in this region that we investigate two phases of the wire ablation process. Observations in the first phase are collsionless and mostly comprised of light ions ejected from the initial corona. The second phase is observed when the wire core is ablated and heavy ions dominate collisions in the stagnation region. In this presentation we will show how dual-wavelength interferometric techniques can provide information about electron and atomic densities from experiments. Additionally, we expect white-light emission to provide a qualitative confirmation of the instabilities observed from our experiments. The material is based upon work supported by the Air Force Office of Scientific Research under Award Number 16RYCOR289.

Study of the structure of turbulent shear flows at supersonic speeds and high Reynolds number

NASA Technical Reports Server (NTRS)

Smits, A. J.; Bogdonoff, S. M.

1984-01-01

A major effort to improve the accuracies of turbulence measurement techniques is described including the development and testing of constant temperature hot-wire anemometers which automatically compensate for frequency responses. Calibration and data acquisition techniques for normal and inclined wires operated in the constant temperature mode, flow geometries, and physical models to explain the observed behavior of flows are discussed, as well as cooperation with computational groups in the calculation of compression corner flows.

Nanowire and microwire fabrication technique and product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumant, Anirudha V.; Zach, Michael; Marten, Alan David

A continuous or semi-continuous process for fabricating nanowires or microwires makes use of the substantially planar template that may be moved through electrochemical solution to grow nanowires or microwires on exposed conductive edges on the surface of that template. The planar template allows fabrication of the template using standard equipment and techniques. Adhesive transfer may be used to remove the wires from the template and in one embodiment to draw a continuous wire from the template to be wound around the drum.

Temperature and field dependence of critical currents in V/sub 3/Ga wire produced by the MJR technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francavilla, T.L.; Gubser, D.U.; Pande, C.S.

1985-03-01

The temperature dependence of V/sub 3/Ga multifilamentary wire produced by the modified jelly roll technique is reported as a function of applied magnetic field in the range 10K - 14K and 0-13T. Parameters which relate J /SUB c/ to H at 4.2K were found to apply at these temperatures and fields. The form of the temperature dependence of the critical current density is compared with theory.

Nickel-titanium wire as a flexor tendon suture material: an ex vivo study.

PubMed

Karjalainen, T; Göransson, H; Viinikainen, A; Jämsä, T; Ryhänen, J

2010-07-01

Nickel-titanium shape memory alloy (NiTi) is a new suture material that is easy to handle, is strong, and biocompatible. The purpose of this study was to evaluate the material properties and biomechanical behaviour of 150 microm and 200 microm NiTi wires in flexor tendon repair. Braided polyester (4-0 Ethibond) was used as control. Fifty fresh-frozen porcine flexor tendons were repaired using the Pennington modification of the Kessler repair or a double Kessler technique. NiTi wires were stiffer and reached higher tensile strength compared to braided polyester suture. Repairs with 200 microm NiTi wire had a higher yield force, ultimate force and better resistance to gapping than 4-0 braided polyester repairs. Repairs made with 200 microm NiTi wire achieved higher stiffness and ultimate force than repairs made with 150 microm NiTi wire.

Sternal closure reinforced with rib heads: a novel technique for prevention and treatment of sternal dehiscence.

PubMed

Vural, A Hakan; Yalçinkaya, Serhat; Türk, Tamer; Oztürk, Alpaslan; Sezen, Mustafa; Yavuz, Senol; Ozyazicioglu, Ahmet

2007-01-01

When a sternotomy cannot be performed at the midline and/or there is infection at the operation site, sternotomy revision can cause problems that increase the mortality and morbidity of the patients. There is no agreement on the best treatment method. In this paper we present a modified wiring technique. This technique consisted of wrapping wires twice around each rib head and placing standard circumferential wire sutures, thus providing full stability by decreasing the load on the sternum using only steel wires. The study group included 23 patients with sternal dehiscence because of inappropriate sternotomy (n = 10) and/or mediastinitis (n = 13). Two mediastinal tubes were placed for irrigation in 13 patients with mediastinitis and/or wound infection, and mobilization and interposition of omentum as an axial graft was performed in 2 patients. Irrigation and antibiotherapy were continued for 4 to 6 weeks. Complete wound healing was obtained in all patients. Twenty-two patients treated with this technique survived. One patient died on postoperative 42nd day because of renal insufficiency and multi-organ failure. Early and aggressive debridement of infected and necrotic tissue, irrigation, and antibiotics are necessary for successful treatment, but we believe that the most important factor is full stabilization of the sternal tissue with minimal use of foreign stabilization material. Despite the limited number of cases, we suggest that our stabilization technique seems to be successful in achieving full stabilization even in infected and fragile sternal bony tissue in patients with sternal dehiscence and/or inappropriate sternotomy.

Electron beams scanning: A novel method

NASA Astrophysics Data System (ADS)

Askarbioki, M.; Zarandi, M. B.; Khakshournia, S.; Shirmardi, S. P.; Sharifian, M.

2018-06-01

In this research, a spatial electron beam scanning is reported. There are various methods for ion and electron beam scanning. The best known of these methods is the wire scanning wherein the parameters of beam are measured by one or more conductive wires. This article suggests a novel method for e-beam scanning without the previous errors of old wire scanning. In this method, the techniques of atomic physics are applied so that a knife edge has a scanner role and the wires have detector roles. It will determine the 2D e-beam profile readily when the positions of the scanner and detectors are specified.

Adaptive composites with embedded NiTiCu wires

NASA Astrophysics Data System (ADS)

Balta-Neumann, J. Antonio; Michaud, Veronique J.; Parlinska, Magdelena; Gotthardt, Rolf; Manson, Jan-Anders E.

2001-07-01

Adaptive composites have been produced by embedding prestrained shape memory alloy (SMA) wires into an epoxy matrix, reinforced with aramid fibers. These materials demonstrate attractive effects such as shape change or a shift in the vibration frequency upon activation. When heated above their transformation temperature, the wires' strain recovery is confined, and recovery stresses are generated. As a result, if the wires are placed along the neutral axis of a composite beam, a shift in resonance vibration frequency can be observed. To optimize the design of such composites, the matrix - SMA wire interfacial shear strength has been analyzed with the pull out testing technique. It is shown that the nature of the wire surface influences the interfacial shear strength, and that satisfactory results are obtained for SMA wires with a thin oxide layer. Composite samples consisting of two different types of pre- strained NiTiCu wires embedded in either pure epoxy matrix or Kevlar-epoxy matrix were produced. The recovery force and vibration response of composites were measured in a clamped-clamped configuration, to assess the effect of wire type and volume fraction. The results are highly reproducible in all cases with a narrow hysteresis loop, which makes NiTiCu wires good candidates for adaptive composites. The recovery forces increase with the volume fraction of the embedded wires, are higher when the wires are embedded in a low CTE matrix and, at a given temperature, are higher when the wire transformation temperature is lower.

Necessary Conditions for Accurate, Transient Hot-Wire Measurements of the Apparent Thermal Conductivity of Nanofluids are Seldom Satisfied

NASA Astrophysics Data System (ADS)

Antoniadis, Konstantinos D.; Tertsinidou, Georgia J.; Assael, Marc J.; Wakeham, William A.

2016-08-01

The paper considers the conditions that are necessary to secure accurate measurement of the apparent thermal conductivity of two-phase systems comprising nanoscale particles of one material suspended in a fluid phase of a different material. It is shown that instruments operating according to the transient hot-wire technique can, indeed, produce excellent measurements when a finite element method (FEM) is employed to describe the instrument for the exact geometry of the hot wire. Furthermore, it is shown that an approximate analytic solution can be employed with equal success, over the time range of 0.1 s to 1 s, provided that (a) two wires are employed, so that end effects are canceled, (b) each wire is very thin, less than 30 \\upmu m diameter, so that the line source model and the corresponding corrections are valid, (c) low values of the temperature rise, less than 4 K, are employed in order to minimize the effect of convection on the heat transfer in the time of measurement of 1 s, and (d) insulated wires are employed for measurements in electrically conducting or polar liquids to avoid current leakage or other electrical distortions. According to these criteria, a transient hot-wire instrument has been designed, constructed, and employed for the measurement of the enhancement of the thermal conductivity of water when TiO2 or multi-wall carbon nanotubes (MWCNT) are added. These new results, together with a critical evaluation of other measurements, demonstrate the importance of proper implementation of the technique.

Apparatus and method for pulsed laser deposition of materials on wires and pipes

DOEpatents

Fernandez, Felix E.

2003-01-01

Methods and apparatuses are disclosed which allow uniform coatings to be applied by pulsed laser deposition (PLD) on inner and outer surfaces of cylindrical objects, such as rods, pipes, tubes, and wires. The use of PLD makes this technique particularly suitable for complex multicomponent materials, such as superconducting ceramics. Rigid objects of any length, i.e., pipes up to a few meters, and with diameters from less than 1 centimeter to over 10 centimeters can be coated using this technique. Further, deposition is effected simultaneously onto an annular region of the pipe wall. This particular arrangement simplifies the apparatus, reduces film uniformity control difficulties, and can result in faster operation cycles. In addition, flexible wires of any length can be continuously coated using the disclosed invention.

Shelf arthroplasty by minimal invasive surgery: technique and results of 76 cases.

PubMed

Chiron, P; Laffosse, J M; Bonnevialle, N

2007-01-01

Shelf arthroplasty is an old technique which by a classical approach, proposed by Lance in 1925, had a low morbidity rate and long term known results. A minimal invasive approach reduces the magnitude of the operation, its consequences and might allow one to broaden its indications. The approach is 4 cm long at the anterolateral part of the hip, through the space between tensor fascia latae and gluteus muscles. A 3x3 cm cortical-cancellous autograft is applied using a guide wire positioned by fluoroscopy and the osteosynthesis is based on a cannulated screw. 76 cases were reviewed over two years (4.6 years average, 2-8 years). The average hospitalization period lasted for three days; patients have to respect partial weight bearing for two months and no one has been placed in a re-education center. 75% patients had a completely painless hip without limiting their activity. 93% shelves are consolidated with a callus in three months; 6% nonunion was due, in part, to a technical mistake. No infection, no phlebitis, no palsy of the cutaneo lateral nerve has been evidenced.

Strategies for the Management of SVC Stent Migration into the Right Atrium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, J. D., E-mail: drjeremytaylor@yahoo.co.uk; Lehmann, E. D.; Belli, A.-M.

Purpose. Stent migration into the right atrium is a potentially fatal complication of stenting in the venous system and is most likely to occur during the treatment of superior vena cava obstruction. Endovascular approaches that can salvage this hazardous situation are described and the keys to successful treatment are highlighted. Materials and Methods. Four different strategies are reviewed: (1) snaring the stent directly, (2) angioplasty balloon-assisted snaring of the stent, (3) guide wire-assisted snaring of the stent, and (4) superior vena cava-to-inferior vena cava bridging stent. Results. These techniques have been employed in the successful management of four cases. Nomore » short- or long-term complications as a result of these maneuvers have been identified. Additional treatment of the underlying disease was possible at the same time in each case. Conclusion. We conclude that prompt management of right atrial stent migration is essential and can be successfully achieved by a variety of 'bale-out' techniques which are within the technical range of most interventional radiologists.« less

Manufacture and quality control of interconnecting wire harnesses, Volume 3

NASA Technical Reports Server (NTRS)

1972-01-01

The document covers interconnecting wire harnesses defined in the design standard, including type 6, enclosed in TFE heat shrink tubing; and type 7, flexible armored. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

-X Mixing in T- and V-Shaped Quantum Wires

NASA Astrophysics Data System (ADS)

di Carlo, A.; Pescetelli, S.; Kavokin, A.; Vladimirova, M.; Lugli, P.

1997-11-01

We have applied both tight-binding (TB) and multivalley envelope function (MEF) techniques to calculate the electronic states in T- and V-shaped realistic quantum wires taking into account -X mixing in the conduction band. Strong reduction of the electron quantization energy due to the off-resonant -X mixing has been found in all types of quantum wires. This effect appears to be tied to the localization of the electron wave function and to its overlap with atomic layers next to interfaces.

Transfissural Route Used for Preoperative Localization of Small Pulmonary Lesions with a Short Hook Wire and Suture System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iguchi, Toshihiro, E-mail: iguchi@ba2.so-net.ne.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp

2015-02-15

PurposeWe retrospectively evaluated the results of the transfissural route for preoperative localization with a short hook wire and suture system for video-assisted thoracoscopic surgery (VATS).MethodsEleven patients with 11 tumors underwent CT-guided transfissural placement of a hook wire before VATS. This route was selected for all patients, because the distance between the tumor and interlobar fissure was much shorter than the required distance traversed using the conventional approach. Complications were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.0.ResultsThe hook wire was successfully placed using the transfissural route in all but one case. Of these tenmore » successful placements, two tumors needed a second puncture for optimal placement, because the CT scan showed that the first hook wire was not properly placed in the lung. In one patient, we did not attempt replacement after the first placement was incorrect. In ten successful procedures, the mean distance traversed in the parenchyma of the unaffected lung lobe was 27.9 mm. The distance between the pleura and placed hook wire was significantly shorter than the estimated distance between the pleura and hook wire using the conventional route (mean 16.3 vs. 40.9 mm; P = 0.0002). Grade 1 adverse events occurred (11 pneumothoraxes and 4 pulmonary hemorrhages). No grade 2 or higher adverse event was observed.ConclusionsThe transfissural route used for preoperative localization before VATS is useful for selected patients because this route may allow for more limited lung parenchyma resection.« less

The Fine Wire Technique for Flexor Tenolysis

PubMed Central

Baltodano, Pablo A.; Weinberg, Maxene H.; Whipple, Lauren A.; Gemmiti, Amanda L.; Whipple, Richard E.

2017-01-01

Background: Flexor tenolysis surgery for flexor digitorum profundus and superficialis adhesions is a common procedure performed by hand surgeons. Releasing these adhered tendons can greatly improve hand function and improve quality of life. Recent evidence, however, has shown that the outcomes of tenolysis surgeries are often suboptimal and can result in relapsing adhesions or even tendon ruptures. Methods: This article describes a new technique with potential for reduced complication rates: The Fine Wire Technique for Flexor Tenolysis (FWT). Results: Following FWT, the patient detailed in this article had an excellent recovery of function and no complications: including tendon rupture, infection, hematomas, or any other complications. She reported a major improvement from her preoperative functionality and continues to have this level of success. The wire’s thinness allows for a swift tenolysis. Conclusions: The FWT is a new option available to the hand surgeon associated with good functional results. The wire is readily available to the clinician and is also inexpensive. PMID:29263961

Use of Cryoablation and Osteoplasty Reinforced with Kirschner Wires in the Treatment of Femoral Metastasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdel-Aal, Ahmed Kamel, E-mail: akamel@uabmc.edu; Underwood, Edgar S.; Saddekni, Souheil

2012-10-15

Purpose: We report the case of a 43-year-old man with metastatic breast carcinoma to the proximal right femur resulting in severe painful pathological fracture. The patient experienced severe pain despite large doses of analgesia, resulting in impaired functionality and quality of life. The patient had significant comorbidities, making him a high surgical risk. Materials and Methods: The patient was treated with cryoablation and osteoplasty, followed by a novel technique consisting of osteoplasty reinforced with bone marrow Kirschner wires (K-wires) which will be described in details in this report. Results: The patient reported significant pain relief after the procedure, and gainedmore » right lower extremity functionality, as compared to total immobility before the procedure. Conclusion: Our technique offers an alternative feasible treatment for patients at high surgical risk with pathological fractures in weight-bearing bones, in which osteoplasty alone has a high risk of cement leakage, inadequate fracture reduction, and early refracture. To our knowledge, our technique has not been previously described.« less

Posterior cervical fixation for fracture and degenerative disc disease.

PubMed

An, H S; Coppes, M A

1997-02-01

There are numerous newer techniques that have been developed for the internal fixation of the cervical spine in recent years. Wiring techniques are still appropriate for posterior stabilization of the cervical spine. The halo vest is still widely used for the conservative management of cervical fractures and for postoperative external immobilization. The authors stress that the surgical indications for more modern rigid implants should be adhered to strictly. These implants also should be selected by weighing their advantages versus potential risks. In the upper cervical spine, the surgeon may choose traditional wiring methods and newer C1-C2 screw fixation, occipitocervical plate fixation. For the lower cervical spine, triple wiring technique or lateral mass plating may be used. The surgeon must choose an appropriate device based on the mechanism of injury, pathoanatomy of the lesion, and familiarity with the device, keeping in mind that the goals of internal fixation are stabilization, reduction and maintenance of alignment, early rehabilitation and perhaps enhancement of fusion rates, and avoidance of use of an external halo vest.

The biomechanical analysis of sublaminar wires and cables using luque segmental spinal instrumentation.

PubMed

Parsons, J R; Chokshi, B V; Lee, C K; Gundlapalli, R V; Stamer, D

1997-02-01

Data was gathered from biomechanical testing of 10 thoracic human cadaveric spines. Spines were tested intact and with a Luque rectangle fixed with wire or cable. To compare the rigidity of fixation and intraspinal penetration of sublaminar monofilament wire and multistrand cable under identical conditions using human cadaveric spines. Reports of neurologic and mechanical complications associated with sublaminar wiring techniques have led to the recent development of more flexible multistrand cable systems. The relative performance of flexible cable versus monofilament wire has not been explored fully in a controlled mechanical environment. A servohydraulic mechanical testing machine was used to measure the static mechanical stiffness of sublaminar wire or cable fixation in conjunction with a Luque rectangle for thoracic human cadaveric spine segments in flexion-extension and torsion modes. Cyclic testing was performed in the flexion-extension mode. Intraspinal penetration of wires and cables was measured. Spine fixation with sublaminar wire and cable resulted in constructs of equal stiffness in flexion-extension and torsion modes. Cyclic testing also indicated similar fatigue profiles for wire- and cable-instrumented spines. Wire and cable fixed spines displayed greater stiffness than the intact spines. Cable encroachment of the spinal canal was less than that seen with wire. Sublaminar multistrand cable may be a rational alternative to monofilament wire in segmental spinal instrumentation because it provides less encroachment into the spinal canal. Further, cadaveric spines instrumented with wire and cable display equivalent mechanical behavior, statically and under cyclic loading. The potential advantages of cable, however, must be balanced against a substantial increase in cost relative to wire.

Radiation- and reference base-free navigation procedure for placement of instruments and implants: application to retrograde drilling of osteochondral lesions of the knee joint.

PubMed

Müller, Matthias; Gras, Florian; Marintschev, Ivan; Mückley, Thomas; Hofmann, Gunter O

2009-01-01

A novel, radiation- and reference base-free procedure for placement of navigated instruments and implants was developed and its practicability and precision in retrograde drillings evaluated in an experimental setting. Two different guidance techniques were used: One experimental group was operated on using the radiation- and reference base-free navigation technique (Fluoro Free), and the control group was operated on using standard fluoroscopy for guidance. For each group, 12 core decompressions were simulated by retrograde drillings in different artificial femurs following arthroscopic determination of the osteochondral lesions. The final guide-wire position was evaluated by postoperative CT analysis using vector calculation. High precision was achieved in both groups, but operating time was significantly reduced in the navigated group as compared to the control group. This was due to a 100% first-pass accuracy of drilling in the navigated group; in the control group a mean of 2.5 correction maneuvers per drilling were necessary. Additionally, the procedure was free of radiation in the navigated group, whereas 17.2 seconds of radiation exposure time were measured in the fluoroscopy-guided group. The developed Fluoro Free procedure is a promising and simplified approach to navigating different instruments as well as implants in relation to visually or tactilely placed pointers or objects without the need for radiation exposure or invasive fixation of a dynamic reference base in the bone.

Complex angular and torsional deformities (distal femoral malunions). Preoperative planning using stereolithography and surgical correction with locking plate fixation in four dogs.

PubMed

DeTora, Michael D; Boudrieau, Randy J

2016-09-20

To describe the surgical technique of complex distal femoral deformity correction with the aid of stereolithography apparatus (SLA) biomodels, stabilized with locking plate fixation. Full-size replica epoxy bone biomodels of the affected femurs (4 dogs/ 5 limbs) were used as templates for surgical planning. A rehearsal procedure was performed on the biomodels aided by a guide wire technique and stabilized with locking plate fixation. Surgery performed in all dogs was guided by the rehearsal procedure. All pre-contoured implants were subsequently used in the definitive surgical procedure with minimal modification. All dogs had markedly improved, with near normal functional outcomes; all but one had a mild persistent lameness at the final in-hospital follow-up examination (mean: 54.4 weeks; range: 24-113 weeks after surgery). All femurs healed without complications (mean: 34 weeks, median: 12 weeks; range: 8-12 weeks for closing osteotomies, and 26-113 weeks for opening wedge osteotomies). Long-term follow-up examination (mean: 28.6 months; range: 5-42 months) revealed all but one owner to be highly satisfied with the outcome. Complications were observed in two dogs: prolonged tibiotarsal joint decreased flexion that resolved with physical therapy. In one of these dogs, iatrogenic transection of the long digital extensor tendon was repaired, and the other had a peroneal nerve neurapraxia. Stereolithography apparatus biomodels and rehearsal surgery simplified the definitive surgical corrections of complex femoral malunions and resulted in good functional outcomes.

An Administrator's Guide to Installing a Telephone System.

ERIC Educational Resources Information Center

Forbes, Phyllis Rossiter

1986-01-01

Guidelines for administrators concerning installation of a new campus telephone system address these issues: where to start; location and emergency power; the project team; paperwork; communication among those involved in installation; working with the local operating company; existing wiring; the external cable plant; special needs; and training…

A Principal's Guide to ILS Facilities Installation.

ERIC Educational Resources Information Center

Ross, Tweed W.

1992-01-01

Outlines five facilities considerations that school principals need to address prior to the installation of an integrated learning system (ILS): (1) placement, i.e., labs or classrooms; (2) wiring; (3) environment, including furniture and noise; (4) security, including fire, theft, vandalism, and misuse; and (5) usability, including afterschool…

Numerical Modeling of Nonlinear Thermodynamics in SMA Wires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, D R; Kloucek, P

We present a mathematical model describing the thermodynamic behavior of shape memory alloy wires, as well as a computational technique to solve the resulting system of partial differential equations. The model consists of conservation equations based on a new Helmholtz free energy potential. The computational technique introduces a viscosity-based continuation method, which allows the model to handle dynamic applications where the temporally local behavior of solutions is desired. Computational experiments document that this combination of modeling and solution techniques appropriately predicts the thermally- and stress-induced martensitic phase transitions, as well as the hysteretic behavior and production of latent heat associatedmore » with such materials.« less

Examination of rapid phase change in copper wires to improve material models and understanding of burst

NASA Astrophysics Data System (ADS)

Olles, Joseph; Garasi, Christopher; Ball, J. Patrick

2017-11-01

Electrically-pulsed wires undergo multiple phase changes including a postulated metastable phase resulting in explosive wire growth. Simulations using the MHD approximation attempt to account for the governing physics, but lack the material properties (equations-of-state and electrical conductivity) to accurately predict the phase evolution of the exploding (bursting) wire. To explore the dynamics of an exploding copper wire (in water), we employ a digital micro-Schlieren streak photography technique. This imaging quantifies wire expansion and shock waves emitted from the wire during phase changes. Using differential voltage probes, a Rogowski coil, and timing fiducials, the phase change of the wire is aligned with electrical power and energy deposition. Time-correlated electrical diagnostics and imaging allow for detailed validation of MHD simulations, comparing observed phases with phase change details found in the material property descriptions. In addition to streak imaging, a long exposure image is taken to capture axial striations along the length of the wire. These images are used to compare with results from 3D MHD simulations which propose that these perturbations impact the rate of wire expansion and temporal change in phases. If successful, the experimental data will identify areas for improvement in the material property models, and modeling results will provide insight into the details of phase change in the wire with correlation to variations in the electrical signals.

Occipitocervical fusions in children. Retrospective analysis and technical considerations.

PubMed

Rodgers, W B; Coran, D L; Emans, J B; Hresko, M T; Hall, J E

1999-07-01

This report presents a retrospective analysis of the authors' experience with occipitocervical fusions in children and adolescents during the last 2 decades. A description of an operative technique devised by the senior author (JEH), and a comparison of the results using this and other methods of fusion are given. Twenty-three patients underwent occipitocervical fusion. Fifteen of the patients were operated on using the authors' technique. To achieve stable fixation of the distal cervical vertebra a threaded Kirschner wire was passed transversely through the spinous process; occipital fixation was achieved by the traditional method of wiring corticocancellous bone graft to the skull through burr holes. The occipital wires then were wrapped around the Kirschner wire and the graft was cradled in the resulting nest. Halo immobilization was used in 10 patients for an average of 12.5 weeks (range, 6-24 weeks). Twenty-two patients achieved successful fusion at an average followup of 5.8 years (range, 1-14.33 years). Several complications, including transient quadriplegia in one patient, pseudarthrosis in two (one of which persists), hardware fixation failure in one, unintended distal extension of the fusion, pneumonia, wound infection, halo pin infection, skin breakdown under the halo vest, hydrocephalus, cerebrospinal fluid leak, and traumatic fusion fracture were encountered. Results using the technique described herein are comparable with or better than the results reported in the previous literature, and the results of the patients in this series in whom the technique was not used.

Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Rickman, S. L.; Iamello, C. J.

2016-01-01

Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

Snare-assisted anterograde balloon mitral and aortic valvotomy using Inoue balloon catheter.

PubMed

Krishnan, Mangalath N; Syamkumar, M D; Sajeev, C G; Venugopal, K; Johnson, Francis; Vinaykumar, D; Velayudhan, C C; Jayakumar, T G

2007-01-02

We performed concurrent antegrade mitral and aortic valvotomy using Inoue dilatation catheter in 3 cases of combined rheumatic mitral and aortic stenosis. Following mitral valvotomy by standard procedure, aortic valve was crossed with the help of a floatation catheter. Stiff long length guide wire was fixed in descending aorta using a snare. Inoue catheter was threaded over the wire across the aortic valve and aortic valvotomy completed. Mitral valve area increased from mean 1 cm2 to 2 cm2; aortic gradient dropped from mean of 97 mm to 36 mm. Concurrent anterograde balloon mitral and aortic valvotomy may be effective and safe.

Clinical acceptance and accuracy assessment of spinal implants guided with SpineAssist surgical robot: retrospective study.

PubMed

Devito, Dennis P; Kaplan, Leon; Dietl, Rupert; Pfeiffer, Michael; Horne, Dale; Silberstein, Boris; Hardenbrook, Mitchell; Kiriyanthan, George; Barzilay, Yair; Bruskin, Alexander; Sackerer, Dieter; Alexandrovsky, Vitali; Stüer, Carsten; Burger, Ralf; Maeurer, Johannes; Donald, Gordon D; Gordon, Donald G; Schoenmayr, Robert; Friedlander, Alon; Knoller, Nachshon; Schmieder, Kirsten; Pechlivanis, Ioannis; Kim, In-Se; Meyer, Bernhard; Shoham, Moshe

2010-11-15

Retrospective, multicenter study of robotically-guided spinal implant insertions. Clinical acceptance of the implants was assessed by intraoperative radiograph, and when available, postoperative computed tomography (CT) scans were used to determine placement accuracy. To verify the clinical acceptance and accuracy of robotically-guided spinal implants and compare to those of unguided free-hand procedures. SpineAssist surgical robot has been used to guide implants and guide-wires to predefined locations in the spine. SpineAssist which, to the best of the authors' knowledge, is currently the sole robot providing surgical assistance in positioning tools in the spine, guided over 840 cases in 14 hospitals, between June 2005 and June 2009. Clinical acceptance of 3271 pedicle screws and guide-wires inserted in 635 reported cases was assessed by intraoperative fluoroscopy, where placement accuracy of 646 pedicle screws inserted in 139 patients was measured using postoperative CT scans. Screw placements were found to be clinically acceptable in 98% of the cases when intraoperatively assessed by fluoroscopic images. Measurements derived from postoperative CT scans demonstrated that 98.3% of the screws fell within the safe zone, where 89.3% were completely within the pedicle and 9% breached the pedicle by up to 2 mm. The remaining 1.4% of the screws breached between 2 and 4 mm, while only 2 screws (0.3%) deviated by more than 4 mm from the pedicle wall. Neurologic deficits were observed in 4 cases yet, following revisions, no permanent nerve damage was encountered, in contrast to the 0.6% to 5% of neurologic damage reported in the literature. SpineAssist offers enhanced performance in spinal surgery when compared to free-hand surgeries, by increasing placement accuracy and reducing neurologic risks. In addition, 49% of the cases reported herein used a percutaneous approach, highlighting the contribution of SpineAssist in procedures without anatomic landmarks.

A Comparison of pical Root Resorption in Incisors after Fixed Orthodontic Treatment with Standard Edgewise and Straight Wire (MBT) Method

PubMed Central

Zahed Zahedani, SM; Oshagh, M; Momeni Danaei, Sh; Roeinpeikar, SMM

2013-01-01

Statement of Problem: One of the major outcomes of orthodontic treatment is the apical root resorption of teeth moved during the treatment. Identifying the possible risk factors, are necessary for every orthodontist. Purpose: The aim of this study was to compare the rate of apical root resorption after fixed orthodontic treatment with standard edgewise and straight wire (MBT) method, and also to evaluate other factors effecting the rate of root resorption in orthodontic treatments. Materials and Method: In this study, parallel periapical radiographs of 127 patients imaging a total of 737 individual teeth, were collected. A total of 76 patients were treated by standard edgewise and 51 patients by straight wire method. The periapical radiographs were scanned and then the percentage of root resorption was calculated by Photoshop software. The data were analyzed by Paired-Samples t-test and the Generalized Linear Model adopting the SPSS 15.0. Results: In patients treated with straight wire method (MBT), mean root resorption was 18.26% compared to 14.82% in patients treated with standard edgewise technique (p< .05). Male patients had higher rate of root resorption,statistically significant (p< .05). Age at onset of treatment, duration of treatment, type of dental occlusion, premolar extractions and the use of intermaxillary elastics had no significant effect on the root resorption in this study. Conclusion: Having more root resorption in the straight wire method and less in the standard edgewise technique can be attributed to more root movement in pre-adjusted MBT technique due to the brackets employed in this method. PMID:24724131

A Comparison of pical Root Resorption in Incisors after Fixed Orthodontic Treatment with Standard Edgewise and Straight Wire (MBT) Method.

PubMed

Zahed Zahedani, Sm; Oshagh, M; Momeni Danaei, Sh; Roeinpeikar, Smm

2013-09-01

One of the major outcomes of orthodontic treatment is the apical root resorption of teeth moved during the treatment. Identifying the possible risk factors, are necessary for every orthodontist. The aim of this study was to compare the rate of apical root resorption after fixed orthodontic treatment with standard edgewise and straight wire (MBT) method, and also to evaluate other factors effecting the rate of root resorption in orthodontic treatments. In this study, parallel periapical radiographs of 127 patients imaging a total of 737 individual teeth, were collected. A total of 76 patients were treated by standard edgewise and 51 patients by straight wire method. The periapical radiographs were scanned and then the percentage of root resorption was calculated by Photoshop software. The data were analyzed by Paired-Samples t-test and the Generalized Linear Model adopting the SPSS 15.0. In patients treated with straight wire method (MBT), mean root resorption was 18.26% compared to 14.82% in patients treated with standard edgewise technique (p< .05). Male patients had higher rate of root resorption,statistically significant (p< .05). Age at onset of treatment, duration of treatment, type of dental occlusion, premolar extractions and the use of intermaxillary elastics had no significant effect on the root resorption in this study. Having more root resorption in the straight wire method and less in the standard edgewise technique can be attributed to more root movement in pre-adjusted MBT technique due to the brackets employed in this method.

Intra-operative localisation of thoracic spine level: a simple "'K'-wire in pedicle" technique.

PubMed

Thambiraj, Sathya; Quraishi, Nasir A

2012-05-01

To describe a simple and reliable method of intra-operative localisation of thoracic spine in a single surgical setting. Intra-operative localisation of thoracic spine levels can be difficult due to anatomical constraints, such as scapular shadow, patient's size and poor bone quality. This is particularly true in cases of thoracic discectomies in which the vertebral bodies appear normal. There are several methods described in recent literature to address this. Many of them require a separate procedure which was performed often the previous day. We report a technique which addresses the issue of localising thoracic level intra-operatively. After induction of general anaesthesia, the patient was placed prone and the pedicle of interest was identified using fluoroscopy. A K-wire was then inserted percutaneously into this pedicle under image guidance [confirmed in the antero-posterior (AP) and lateral views]. The wire was then cut close to the skin after bending it. The patient was now positioned laterally and the intended procedure performed through an anterior trans-thoracic approach. The 'K' wire was removed at the end of the procedure. We routinely used this technique in all our thoracic discectomies (four cases in 2 years). There were no intra-operative complications. This method is simple, avoids the patient undergoing two procedures and requires no more ability than placing an implant in the pedicle under fluoroscopy. Placing the 'K' wire into a fixed point like the pedicle facilitates rapid intra-operative viewing of the level of interest and is removed easily at the conclusion of surgery.

Shuttleless toroid winder

DOEpatents

Lindenmeyer, Carl W.

1981-01-01

A lower support receives a toroid at a winding station with the axis of the toroid aligned with a slot in the support. An upper guide member applies an axial force to hold the toroid against the lower support. A pair of movable jaws carried by an indexing mechanism engage the outer surface of the toroid to apply a radial holding force. While the toroid is thus held, a wire is placed axially through the toroid, assisted by a funnel-shaped surface in the upper guide member, and is drawn tight about the toroid by a pair of cooperating draw rollers. When operated in the "full cycle" mode, the operator then actuates a switch which energizes a power drive to release the axial clamp and to drive the indexing mechanism and the jaws to rotate the toroid about its axis. At the same time, the wire is ejected from the draw rollers beneath the toroid so that the operator may grasp it to form another loop. When the toroid is fully indexed, the jaws release it, and the upper guide member is returned to clamp the toroid axially while the indexing mechanism is returned to its starting position. The apparatus may also be operated in a "momentary contact" mode in which the mechanism is driven only for the time a switch is actuated.

Esophageal stenosis in epidermolysis bullosum: a challenge for the endoscopist.

PubMed

De Angelis, Paola; Caldaro, Tamara; Torroni, Filippo; Romeo, Erminia; Foschia, Francesca; di Abriola, Giovanni Federici; Rea, Francesca; El Hachem, May; Genovese, Elisabetta; D'Alessandro, Sandra; Dall'Oglio, Luigi

2011-05-01

Esophageal stenosis is a severe complication in dystrophic epidermolysis bullosa (EB). Endoscopic dilations may cause mucosal injury with stricture recurrence. Our aim was to describe our referral EB-center experience on safety and long-term efficacy of fluoroscopically guided balloon dilation without endoscopy. Over 14 years, 34 patients with EB, previously evaluated with barium esophagogram for dysphagia, underwent balloon esophageal dilation. Under fluoroscopy, a guide wire was introduced via a nostril into the stomach. A 12-mm pneumatic balloon, which passed over the wire, was filled using radio-opaque contrast, dilating the stricture. Orotracheal intubation was avoided. Antibiotics, dexamethasone, and proton-pump inhibitors were administered. Study approval was obtained from our ethical board. Ninety-three dilations were performed. Seventeen patients had a single stenosis. The mean age of onset was 18 years (range, 3-47 years). Thirteen patients underwent one dilation. In 6 cases, endoscopy was necessary to visualize the esophageal lumen. Complications included cervical esophageal perforation (2) and transitory dysphagia (10). Thirty patients were feeding within 24 hours. During the follow-up, 2 patients required a gastrostomy, and 2 patients underwent fundoplication for gastroesophageal reflux disease. Fluoroscopically guided balloon dilation in EB is a safe and well-tolerated procedure. An experienced endoscopy team is necessary in certain cases. Copyright © 2011 Elsevier Inc. All rights reserved.

Successful retrieval of an entrapped Rotablator burr using 5 Fr guiding catheter.

PubMed

Kimura, Masayoshi; Shiraishi, Jun; Kohno, Yoshio

2011-10-01

Although burr entrapment is a rare complication of the Rotablator, it is extremely difficult to retrieve a fixedly entrapped burr without surgical procedure. An 84-year-old male with effort angina had heavily calcified coronary trees as well as severe stenosis in the mid LCx, and moderate stenosis in the proximal LCx, and in the LMT. We planned to perform rotational atherectomy in the LCx lesions. Using 7 Fr Q-curve guiding catheter and Rotawire floppy, we began to ablate using 1.5-mm burr at 200,000 rpm. Because the burr could not pass the proximal stenosis, we exchanged the wire for Rotawire extrasupport and the burr for 1.25-mm burr, and restarted the ablation at 220,000 rpm. Although the burr could manage to pass the proximal stenosis, it had become trapped in the mid LCx lesion. Simple pull on the Rotablator, rotation of the burr, and crossing the Conquest (Confianza) wire could not retrieve it. Thus, we cut off the drive shaft and sheath of the Rotablator, inserted 5 Fr 120-cm straight guiding catheter (Heartrail ST01; Terumo) through the remaining Rotablator system, pushed the catheter tip to the lesion around the burr as well as simultaneously pulled the Rotablator, and finally could retrieve it. Then we implanted stents in the LCx and in the LMT without difficulty. The 5 Fr straight guiding catheter might be useful for retrieving an entrapped burr (1.25-mm burr). Copyright © 2011 Wiley-Liss, Inc.

Assessment of bone healing on tibial fractures treated with wire osteosynthesis associated or not with infrared laser light and biphasic ceramic bone graft (HATCP) and guided bone regeneration (GBR): Raman spectroscopy study

NASA Astrophysics Data System (ADS)

Bastos de Carvalho, Fabíola; Aciole, Gilberth Tadeu S.; Aciole, Jouber Mateus S.; Silveira, Landulfo, Jr.; Nunes dos Santos, Jean; Pinheiro, Antônio L. B.

2011-03-01

The aim of this study was to evaluate, through Raman spectroscopy, the repair of complete tibial fracture in rabbits fixed with wire osteosynthesis - WO, treated or not with infrared laser light (λ 780nm, 50mW, CW) associated or not to the use of HATCP and GBR. Surgical fractures were created under general anesthesia (Ketamine 0.4ml/Kg IP and Xilazine 0.2ml/Kg IP), on the tibia of 15 rabbits that were divided into 5 groups and maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet and had water ad libidum. On groups II, III, IV and V the fracture was fixed with WO. Animals of groups III and V were grafted with hydroxyapatite + GBR technique. Animals of groups IV and V were irradiated at every other day during two weeks (16J/cm2, 4 x 4J/cm2). Observation time was that of 30 days. After animal death the specimens were kept in liquid nitrogen for further analysis by Raman spectroscopy. Raman spectroscopy showed significant differences between groups (p<0.001). It is concluded that IR laser light was able to accelerate fracture healing and the association with HATCP and GBR resulted on increased deposition of calcium hydroxyapatite.

Internal fixation of displaced inferior pole of the patella fractures using vertical wiring augmented with Krachow suturing.

PubMed

Oh, Hyoung-Keun; Choo, Suk-Kyu; Kim, Ji-Wan; Lee, Mark

2015-12-01

We present the surgical technique of separate vertical wiring for displaced inferior pole fractures of the patella combined with Krachow suture and report the surgical outcomes. Between September 2007 to May 2012, 11 consecutive patients (mean age, 54.6 years) with inferior pole fractures of the patella (AO/OTA 34-A1) were retrospectively enrolled in this study. Through longitudinal incision, all patients underwent open reduction and internal fixation by separate vertical wiring combined with Krackow suture. The range of motion, loss of fixation, and Bostman score were primary outcome measures. The union time was 10 weeks after surgery on average (range: 8-12). No patient had nonunion, loss of reduction and wire breakage. There was no case of wound problem and irritation from the implant. At final follow-up, the average range of motion arc was 129.4° (range: 120-140). The mean Bostman score at last follow-up was 29.6 points (range: 28-30) and graded excellent in all cases. Separate vertical wiring combined with Krackow suture for inferior pole fractures of the patella is a useful technique that is easy to perform and can provide stable fixation with excellent results in knee function. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development and Status of Cu Ball/Wedge Bonding in 2012

NASA Astrophysics Data System (ADS)

Schneider-Ramelow, Martin; Geißler, Ute; Schmitz, Stefan; Grübl, Wolfgang; Schuch, Bernhard

2013-03-01

Starting in the 1980s and continuing right into the last decade, a great deal of research has been published on Cu ball/wedge (Cu B/W) wire bonding. Despite this, the technology has not been established in industrial manufacturing to any meaningful extent. Only spikes in the price of Au, improvements in equipment and techniques, and better understanding of the Cu wire-bonding process have seen Cu B/W bonding become more widespread—initially primarily for consumer goods manufacturing. Cu wire bonding is now expected to soon be used for at least 20% of all ball/wedge-bonded components, and its utilization in more sophisticated applications is around the corner. In light of this progress, the present paper comprehensively reviews the existing literature on this topic and discusses wire-bonding materials, equipment, and tools in the ongoing development of Cu B/W bonding technology. Key bonding techniques, such as flame-off, how to prevent damage to the chip (cratering), and bond formation on various common chip and substrate finishes are also described. Furthermore, apart from discussing quality assessment of Cu wire bonds in the initial state, the paper also provides an overview of Cu bonding reliability, in particular regarding Cu balls on Al metalization at high temperatures and in humidity (including under the influence of halide ions).

Hy-wire measurements of atmospheric potential

NASA Astrophysics Data System (ADS)

Holzworth, Robert H.

1984-02-01

A method of directly measuring the electric potential drop across the lowest portion of the atmosphere by using an apparatus called Hy-wire is described. This tethered balloon-borne system has been operated extensively at altitudes near 0.62 km at which voltages over 150 k V were measured with a high impedance device. Also described are measurements of system parameters such as system capacitance (5.6 pf/m), impedance (1010Ω), and response time (tens of seconds). Hy-wire measurements from an around the-clock experiment at Wallops Island, Va., having a characteristic repetitive diurnal pattern of variability exceeding 40% of the mean, are presented. This diurnal pattern is discussed in terms of both local and global current sources. A demonstration using Hy-wire as a lightning channel model is also presented. These experiments have so far been conducted at mid-latitudes but can also be flown from other locations in an effort to determine whether the lowest atmospheric electric circuit is affected by high altitude and possibly global current systems, and if so how much. The data presented in this paper are not definitive about the source of potential variations. The data are, however, representative of the new Hy-wire technique and demonstrative of the potential usefulness of this technique.

It all unraveled from there: case report of a central venous catheter guidewire unraveling.

PubMed

Zerkle, Samuel; Emdadi, Vanessa; Mancinelli, Marc

2014-12-01

Inferior vena cava (IVC) filters can present challenges to emergency physicians in the process of central venous catheter (CVC) placement. A 68-year-old woman presented to the emergency department with severe shortness of breath and was intubated. A central line was placed after the intubation to facilitate peripheral access. A CVC guidewire unraveled during placement after getting caught on an IVC filter. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be aware of the complications that IVC filters can cause in the placement of CVCs. Imaging and identification of IVC filters beforehand will allow for proper planning of how to manage the case in which a filter catches on the guidewire. Simple anecdotal techniques, such as advancing the guidewire and spinning the guidewire between the fingers, can facilitate the removal of the guide wire from the IVC filter. Copyright © 2014 Elsevier Inc. All rights reserved.

Anomalous Coronary Artery From the Opposite Sinus (ACAOS): Technical Challenges During Percutaneous Coronary Intervention.

PubMed

Sinha, Santosh Kumar; Razi, Mahmodula; Mahrotra, Anupam; Aggarwal, Puneet; Singh, Anupam; Rekwal, Lokendra; Tripathi, Sunil; Abhishekh, Nishant Kumar; Krishna, Vinay

2018-04-01

Anomalies of the coronary arteries are reported in 1-2% of patients among diagnostic angiogram. Ectopic origin of right coronary artery (RCA) from opposite sinus is one of the most common and they are mainly benign, but at times may be malignant. We report a case of a 69-year-old male who underwent early invasive percutaneous coronary intervention for non-ST-segment elevation myocardial infarction (NSTEMI) where RCA arising from left sinus at the root of left main artery was culprit and various technical challenges were encountered while intervening in form of cannulation to tracking of hardwares. RCA was cannulated with floating wire technique using hockey stick guide catheter and revascularized by deployment of 3.5 × 38 mm Promus Premier Everolimus eluting stent (Boston Scientific, USA). To the best of our knowledge, this is the first ever report of ectopic RCA being revascularized by using hockey stick catheter.

Visualization and imaging methods for flames in microgravity

NASA Technical Reports Server (NTRS)

Weiland, Karen J.

1993-01-01

The visualization and imaging of flames has long been acknowledged as the starting point for learning about and understanding combustion phenomena. It provides an essential overall picture of the time and length scales of processes and guides the application of other diagnostics. It is perhaps even more important in microgravity combustion studies, where it is often the only non-intrusive diagnostic measurement easily implemented. Imaging also aids in the interpretation of single-point measurements, such as temperature, provided by thermocouples, and velocity, by hot-wire anemometers. This paper outlines the efforts of the Microgravity Combustion Diagnostics staff at NASA Lewis Research Center in the area of visualization and imaging of flames, concentrating on methods applicable for reduced-gravity experimentation. Several techniques are under development: intensified array camera imaging, and two-dimensional temperature and species concentrations measurements. A brief summary of results in these areas is presented and future plans mentioned.

Improvement of sternal closure stability with reinforced steel wires.

PubMed

McGregor, Walter E; Payne, Maryann; Trumble, Dennis R; Farkas, Kathleen M; Magovern, James A

2003-11-01

Sternal dehiscence occurs when steel wires pull through sternal bone. This study tests the hypothesis that closure stability can be improved by jacketing sternal wires with stainless steel coils, which distribute the force exerted on the bone over a larger area. Midline sternotomies were performed in 6 human cadavers (4 male). Two sternal closure techniques were tested: (1) approximation with six interrupted wires, and (2) the same closure technique reinforced with 3.0-mm-diameter stainless steel coils that jacket wires at the lateral and posterior aspects of the sternum. Intrathoracic pressure was increased with an inflatable rubber bladder placed beneath the anterior chest wall, and sternal separation was measured by means of sonomicrometry crystals. In each trial, intrathoracic pressure was increased until 2.0 mm of motion was detected. Differences in displacement pressures between groups were examined at 0.25-mm intervals using the paired Student's t test. The use of coil-reinforced closures produced significant improvement in sternal stability at all eight displacement levels examined (p < 0.03). Mean pressure required to cause displacement increased 140% (15.5 to 37.3 mm Hg) at 0.25 mm of separation, 103% (34.3 to 69.8 mm Hg) at 1.0 mm of separation, and 122% (46.8 to 103.8 mm Hg) at 2.0 mm of separation. Reinforcement of sternal wires with stainless steel coils substantially improves stability of sternotomy closure in a human cadaver model.

[Biomechanical testing of the new torque-segmented arch (TSA)].

PubMed

Wichelhaus, A; Sander, F G

1995-07-01

New torque-segmented arch wires are presented which consist of a superelastic anterior component with 30 degrees or 45 degrees torque and which are connected to 2 steel lateral components by means of a crimped connector. When using such torque-segmented arch wires, the crimped connector rests mesially to the canine bracket and the lateral components exhibit a torque of 0 degree. The use of the torque-segmented arch wires requires the practitioner to adjust the anterior tooth segment, to bend in first order bends in the steel lateral portion as well as to bend in a sweep to avoid an anterior tooth extrusion, and, if desired, to bend in third order bends to influence premolars and molars. In some cases the simultaneous application of palatal arches can become necessary, because each torque transfer results in a transversal enlargement in the molar area. Compared to conventional steel wires with dimensions of 0.016 x 0.022 in which an anterior tooth torque is bent, the torque segmented arch wires exhibit considerably fewer side effects, but there is a larger distally rotating moment for the molars. 1. When applying torque-segmented arch wires, the extrusive force transferred to the anterior teeth is considerably smaller. 2. The protrusive force acting on the anterior teeth is also considerably smaller, which results in a reduced demand being placed on the anchorage of the molars. 3. The torque transfer to the incisors rests in a quite moderate range, even in the case of a 50 degrees torque. For this reason, the practitioner can expect diminished or no resorptions at all compared to the aforementioned steel wires. 4. The Martensite plateau of the torque-segmented arch wires exhibit constant moments in large areas so that such arch wires can be used in almost every anterior tooth position. 5. The segmented wires presented here can be applied not only in the case of the standard edgewise technique but also in each case of the straight-wire technique. 6. These new arch wires require no readjustment of torque values. 7. To control the transferred torque values it is recommended that the already transferred torque values be monitored during each check-up with the help of the described torque key. 8. When the torque values of the brackets are known, the torque key renders frequent patient X-rays superfluous. 9. When the desired torque values are attained, treatment can proceed using conventional arch wires.

Improvement in the transport critical current density and microstructure of isotopic Mg11B2 monofilament wires by optimizing the sintering temperature

PubMed Central

Qiu, Wenbin; Jie, Hyunseock; Patel, Dipak; Lu, Yao; Luzin, Vladimir; Devred, Arnaud; Somer, Mehmet; Shahabuddin, Mohammed; Kim, Jung Ho; Ma, Zongqing; Dou, Shi Xue; Hossain, Md. Shahriar Al

2016-01-01

Superconducting wires are widely used in fabricating magnetic coils in fusion reactors. In consideration of the stability of 11B against neutron irradiation and lower induced radio-activation properties, MgB2 superconductor with 11B serving as boron source is an alternative candidate to be used in fusion reactor with severe irradiation environment. In present work, a batch of monofilament isotopic Mg11B2 wires with amorphous 11B powder as precursor were fabricated using powder-in-tube (PIT) process at different sintering temperature, and the evolution of their microstructure and corresponding superconducting properties was systemically investigated. Accordingly, the best transport critical current density (Jc) = 2 × 104 A/cm2 was obtained at 4.2 K and 5 T, which is even comparable to multi-filament Mg11B2 isotope wires reported in other work. Surprisingly, transport Jc vanished in our wire which was heat-treated at excessively high temperature (800 °C). Combined with microstructure observation, it was found that lots of big interconnected microcracks and voids that can isolate the MgB2 grains formed in this whole sample, resulting in significant deterioration in inter-grain connectivity. The results can be a constructive guide in fabricating Mg11B2 wires to be used as magnet coils in fusion reactor systems such as ITER-type tokamak magnet. PMID:27824144

Planning for Technology: An Administrator's Guide to the Next Century.

ERIC Educational Resources Information Center

Day, William C.

1998-01-01

Discusses ways for preparing schools for integrating technology, including designing the wiring infrastructure, equipment purchases, furniture needs, and ergonomic considerations. Describes four levels of Internet connectivity access and provides a list of contact names, phone numbers, and Web sites for technology fund information from each state.…

Rocket center Peenemuende - Personal memories

NASA Technical Reports Server (NTRS)

Dannenberg, Konrad; Stuhlinger, Ernst

1993-01-01

A brief history of Peenemuende, the rocket center where Von Braun and his team developed the A-4 (V-2) rocket under German Army auspices, and the Air Force developed the V-1 (buzz bomb), wire-guided bombs, and rocket planes, is presented. Emphasis is placed on the expansion of operations beginning in 1942.

Avionics electromagnetic interference immunity and environment

NASA Technical Reports Server (NTRS)

Clarke, C. A.

1986-01-01

Aircraft electromagnetic spectrum and radio frequency (RF) field strengths are charted, profiling the higher levels of electromagnetic voltages encountered by the commercial aircraft wiring. Selected military, urban, and rural electromagnetic field levels are plotted and provide a comparison of radiation amplitudes. Low frequency magnetic fields and electric fields from 400 H(Z) power systems are charted versus frequency and wire separation to indicate induced voltages on adjacent or neighboring circuits. Induced EMI levels and attenuation characteristics of electric, magnetic, RF fields, and transients are plotted and graphed for common types of wire circuits. The significance of wire circuit returns and shielding is emphasized to highlight the techniques that help block the paths of electromagnetic interference and maintain avionic interface signal quality.

Offline Impedance Measurements for Detection and Mitigation of Dangerous Implant Interactions: An RF Safety Prescreen

PubMed Central

Ellenor, Christopher W; Stang, Pascal P; Etezadi-Amoli, Maryam; Pauly, John M; Scott, Greig C

2015-01-01

Purpose The concept of a “radiofrequency safety prescreen” is investigated, wherein dangerous interactions between radiofrequency fields used in MRI, and conductive implants in patients are detected through impedance changes in the radiofrequency coil. Theory The behavior of coupled oscillators is reviewed, and the resulting, observable impedance changes are discussed. Methods A birdcage coil is loaded with a static head phantom and a wire phantom with a wire close to its resonant length, the shape, position, and orientation of which can be changed. Interactions are probed with a current sensor and network analyzer. Results Impedance spectra show dramatic, unmistakable splitting in cases of strong coupling, and strong correlation is observed between induced current and scattering parameters. Conclusions The feasibility of a new, low-power prescreening technique has been demonstrated in a simple phantom experiment, which can unambiguously detect resonant interactions between an implanted wire and an imaging coil. A new technique has also been presented which can detect parallel transmit null modes for the wire. Magn Reson Med 73:1328–1339, 2015. © 2014 Wiley Periodicals, Inc. PMID:24623586

Turbulence measurements in a complex plowfield using a crossed hot-wire. M.S. Thesis

NASA Technical Reports Server (NTRS)

Mckillop, B. E.

1983-01-01

Turbulence was quantified in complex axisymmetric, nonreacting, nonswirling flowfields using a crossed hot-wire anemometer. Mean velocity, turbulence intensities, turbulent viscosity, and Reynolds tree were measured in round free jet and confined jet flowfields. The confined jet, a model of an axisymmetric can combustor, had an expansion ratio D/d=2, an expansion angle of 90 deg, and an axial location increments of 0.5 diameters. The confined jet was studied with and without a contraction nozzle. Free jet measurements validated the experimental technique and data reduction. Results show good agreement with those of previous research. Measurements in the confined jet indicate that the cross hot-wire used cannot handle axial flow reversal and the experimental technique is inadequate for measuring time-mean radial velocity. Other quantities show a high level of comparability.

Development of improved electroforming technique. [for fabricating regeneratively cooled thrust chambers

NASA Technical Reports Server (NTRS)

Mccandles, L. C.; Davies, L. G.

1973-01-01

Techniques were studied to reinforce or strengthen electroformed nickel to allow a fuller utilization of electroforming as a reliable and low cost fabrication technique for regenerately cooled thrust chambers. Techniques for wire wrapping while electrodepositing were developed that can result in a structurally strong wall with less weight than a conventional electroformed wall. Also a technique of codepositing submicron sized THO2 particles with the nickel to form a dispersion strengthened structure was evaluated. The standard nickel cylinders exhibited an average hoop strength of 80,000 psi with a yield strength of 65,000 psi and a modulus of 25.6 x 10 to the 6th power psi. The as produced dispersion strengthened nickel showed a hoop strength of 97,000 psi with a yield strength of 67,000 psi. This is an increase of 17,000 psi or 21% over the standard nickel hoop strength. The wire wrapping cylinders showed an increased strength over the standard nickel test samples of 26,000 to 66,800 psi which is in the range of 26 to 104% increase in strength over the base standard nickel. These latter test results are indicative of a volume percent wire reinforcement from 15 to 31. The measured hoop strengths agree with calculated composite strengths based upon rule of mixtures.

Polydimethylsiloxane pressure sensors for force analysis in tension band wiring of the olecranon.

PubMed

Zens, Martin; Goldschmidtboeing, Frank; Wagner, Ferdinand; Reising, Kilian; Südkamp, Norbert P; Woias, Peter

2016-11-14

Several different surgical techniques are used in the treatment of olecranon fractures. Tension band wiring is one of the most preferred options by surgeons worldwide. The concept of this technique is to transform a tensile force into a compression force that adjoins two surfaces of a fractured bone. Currently, little is known about the resulting compression force within a fracture. Sensor devices are needed that directly transduce the compression force into a measurement quality. This allows the comparison of different surgical techniques. Ideally the sensor devices ought to be placed in the gap between the fractured segments. The design, development and characterization of miniaturized pressure sensors fabricated entirely from polydimethylsiloxane (PDMS) for a placement within a fracture is presented. The pressure sensors presented in this work are tested, calibrated and used in an experimental in vitro study. The pressure sensors are highly sensitive with an accuracy of approximately 3 kPa. A flexible fabrication process for various possible applications is described. The first in vitro study shows that using a single-twist or double-twist technique in tension band wiring of the olecranon has no significant effect on the resulting compression forces. The in vitro study shows the feasibility of the proposed measurement technique and the results of a first exemplary study.

Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhai, Yuhu; Calzolaio, Ciro; Senatore, Carmine

2014-08-01

Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanicalmore » loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.« less

A novel monolithic piezoelectric actuated flexure-mechanism based wire clamp for microelectronic device packaging.

PubMed

Liang, Cunman; Wang, Fujun; Tian, Yanling; Zhao, Xingyu; Zhang, Hongjie; Cui, Liangyu; Zhang, Dawei; Ferreira, Placid

2015-04-01

A novel monolithic piezoelectric actuated wire clamp is presented in this paper to achieve fast, accurate, and robust microelectronic device packaging. The wire clamp has compact, flexure-based mechanical structure and light weight. To obtain large and robust jaw displacements and ensure parallel jaw grasping, a two-stage amplification composed of a homothetic bridge type mechanism and a parallelogram leverage mechanism was designed. Pseudo-rigid-body model and Lagrange approaches were employed to conduct the kinematic, static, and dynamic modeling of the wire clamp and optimization design was carried out. The displacement amplification ratio, maximum allowable stress, and natural frequency were calculated. Finite element analysis (FEA) was conducted to evaluate the characteristics of the wire clamp and wire electro discharge machining technique was utilized to fabricate the monolithic structure. Experimental tests were carried out to investigate the performance and the experimental results match well with the theoretical calculation and FEA. The amplification ratio of the clamp is 20.96 and the working mode frequency is 895 Hz. Step response test shows that the wire clamp has fast response and high accuracy and the motion resolution is 0.2 μm. High speed precision grasping operations of gold and copper wires were realized using the wire clamper.

Biomechanical analysis comparing three C1-C2 transarticular screw salvaging fixation techniques.

PubMed

Elgafy, Hossein; Potluri, Tejaswy; Goel, Vijay K; Foster, Scott; Faizan, Ahmad; Kulkarni, Nikhil

2010-02-15

This is an in vitro biomechanical study. To compare the biomechanical stability of the 3 C1-C2 transarticular screw salvaging fixation techniques. Stabilization of the atlantoaxial complex is a challenging procedure because of its complicated anatomy. Many posterior stabilization techniques of the atlantoaxial complex have been developed with C1-C2 transarticular screw fixation been the current gold standard. The drawback of using the transarticular screws is that it has a potential risk of vertebral artery injury due to a high riding transverse foramen of C2 vertebra, and screw malposition. In such cases, it is not recommended to proceed with inserting the contralateral transarticular screw and the surgeon should find an alternative to fix the contralateral side. Many studies are available comparing different atlantoaxial stabilization techniques, but none of them compared the techniques to fix the contralateral side while using the transarticular screw on one side. The current options are C1 lateral mass screw and short C2 pedicle screw or C1 lateral mass screw and C2 intralaminar screw, or C1-C2 sublaminar wire. Nine fresh human cervical spines with intact ligaments (C0-C4) were subjected to pure moments in the 6 loading directions. The resulting spatial orientations of the vertebrae were recorded using an Optotrak 3-dimensional Motion Measurement System. Measurements were made sequentially for the intact spine after creating type II odontoid fracture and after stabilization with unilateral transarticular screw placement across C1-C2 (TS) supplemented with 1 of the 3 transarticular salvaging techniques on the contralateral side; C1 lateral mass screw and C2 pedicle screw (TS+C1LMS+C2PS), C1 lateral mass and C2 intralaminar screw (TS+C1LMS+C2ILS), or sublaminar wire (TS + wire). The data indicated that all the 3 stabilization techniques significantly decreased motion when compared to intact in all the loading cases (left/right lateral bending, left/right axial rotation, flexion) except extension. All the 3 instrumented specimens were equally stable in extension/flexion and lateral bending modes. TS+C1LMS+C2PS was equivalent to TS+C1LMS+C2ILS (P > 0.05) and superior to TS + wire in axial rotation (P < 0.05). Also, TS+C1LMS+C2ILS was superior to TS + wire in axial rotation (P < 0.05). Fixation of atlantoaxial complex using unilateral transarticular screw supplemented with contralateral C1 lateral mass and C2 intralaminar screws is biomechanically equivalent to C1 lateral mass and C2 pedicle screws and both are biomechanically superior to C1-C2 sublaminar wire in axial rotation.

Simple and Efficient Technique for Correction of Unilateral Scissor Bite Using Straight Wire.

PubMed

Dolas, Siddhesh Gajanan; Chitko, Shrikant Shrinivas; Kerudi, Veerendra Virupaxappa; Patil, Harshal Ashok; Bonde, Prasad Vasudeo

2016-03-01

Unilateral scissor bite is a relatively rare malocclusion. However, its correction is often difficult and a challenge for the clinician. This article presents simple and efficient technique for the correction of severe unilateral scissor bite in a 14 year old boy, using 0.020 S.S. A. J. Wilcock wire (premium plus) out of the spool, with minimal adjustments and placed in mandibular arch. After about six weeks time, good amount of correction was seen in the lower arch and the lower molar had been relieved of scissor bite.

Practical microstructured and plasmonic terahertz waveguides

NASA Astrophysics Data System (ADS)

Markov, Andrey

The terahertz frequency range, with frequencies lying between 100 GHz and 10 THz, has strong potential for various technological and scientific applications such as sensing, imaging, communications, and spectroscopy. Most terahertz (THz) sources are immobile and THz systems use free-space propagation in dry air where losses are minimal. Designing efficient THz waveguides for flexible delivery of broadband THz radiation is an important step towards practical applications of terahertz techniques. THz waveguides can be very useful on the system integration level when used for connection of the diverse THz point devices, such as sources, filters, sensor cells, detectors, etc. The most straightforward application of waveguides is to deliver electromagnetic waves from the source to the point of detection. Cumbersome free-space optics can be replaced by waveguides operating in the THz range, which could lead to the development of compact THz time domain spectroscopy systems. Other promising applications of THz waveguides are in sensing and imaging. THz waveguides have also been shown to operate in subwavelength regimes, offering mode confinement in waveguide structures with a size smaller than the diffraction limit, and thus, surpassing the resolution of free-space THz imaging systems. In order to design efficient terahertz waveguides, the frequency dependent loss and dispersion of the waveguide must be minimized. A possible solution would be to increase the fraction of mode power propagating through air. In this thesis, the usage of planar porous air/dielectric waveguides and metal wire/dielectric hybrid terahertz fibers will be discussed. First, I present a novel design of a planar porous low-loss waveguide, describe its fabrication, and characterize it in view of its potential applications as a low-loss waveguide and sensor in the THz spectral range. The waveguide structure features a periodic sequence of layers of thin (25-50 mum) polyethylene film that are separated by low-loss air layers of comparable thickness. A large fraction of the modal fields in these waveguides is guided in the low-loss air region, thus effectively reducing the waveguide transmission losses. I consider that such waveguides can be useful not only for low-loss THz wave delivery, but also for sensing of biological and chemical specimens in the terahertz region, by placing the recognition elements directly into the waveguide microstructure. The main advantage of the proposed planar porous waveguide is the convenient access to its optical mode, since the major portion of THz power launched into such a waveguide is confined within the air layers. Moreover, small spacing between the layers promotes rapid loading of the analyte into the waveguide due to strong capillary effect (< 1 s filling of a 10 cm long waveguide with an analyte). The transmission and absorption properties of such waveguides have been investigated both experimentally using THz-TDS spectroscopy and theoretically using finite element software. The modal refractive index of porous waveguides is smaller compared to pure polymer and it is easy to adjust by changing the air spacing between the layers, as well as the number of layers in the core. The porous waveguide exhibits considerably smaller transmission losses than bulk material. In the following chapters I review another promising approach towards designing of low-loss, low-dispersion THz waveguides. The hybrid metal/dielectric waveguides use a plasmonic mode guided in the gap between two parallel wires that are, in turn, encapsulated inside a low-loss, low-refractive index, micro-structured cladding that provides mechanical stability and isolation from the environment. I describe several promising techniques that can be used to encapsulate the two-wire waveguides, while minimizing the negative impact of dielectric cladding on the waveguide optical properties. In particular, I detail the use of low-density foams and microstructured plastic claddings as two enabling materials for the two-wire waveguide encapsulation. The hybrid fiber design is more convenient for practical applications than a classic two metal wire THz waveguide as it allows direct manipulations of the fiber without the risk of perturbing its core-guided mode. I present a detailed analysis of the modal properties of the hybrid metal/dielectric waveguides, compare them with the properties of a classic two-wire waveguide, and then present strategies for the improvement of hybrid waveguide performance by using higher cladding porosity or utilizing inherently porous cladding material. I study coupling efficiency into hybrid waveguides and conclude that it can be relatively high (>50%) in the broad frequency range ˜0.5 THz. Not surprisingly, optical properties of such fibers are inferior to those of a classic two-wire waveguide due to the presence of lossy dielectric near an inter-wire gap. At the same time, composite fibers outperform porous fibers of the same geometry both in bandwidth of operation and in lower dispersion. I demonstrate that hybrid metal/dielectric porous waveguides can have a very large operational bandwidth, while supporting tightly confined, air-bound modes both at high and low frequencies. This is possible as, at higher frequencies, hybrid fibers can support ARROW-like low-loss air-bound modes, while changing their guidance mechanism to plasmonic confinement in the inter-wire air gap at lower frequencies. Finally, I describe an intriguing resonant property of some hybrid plasmonic modes of metal / dielectric waveguides that manifests itself in the strong frequency dependent change in the modal confinement from dielectric-bound to air-bound. I discuss how this property can be used to construct THz refractometers. Introduction of even lossless analytes into the fiber core leads to significant changes in the modal losses, which is used as a transduction mechanism. The resolution of the refractometer has been investigated numerically as a function of the operation frequency and the geometric parameters of the fiber. With a refractive index resolution on the order of ˜10-3 RIU, the composite fiber-based sensor is capable of identifying various gaseous analytes and aerosols or measuring the concentration of dust particles in the air.

Effect of dry heat and steam sterilization on load-deflection characteristics of β-titanium wires: An in vitro study

PubMed Central

Alavi, Shiva; Sinaee, Neda

2012-01-01

Background: Sterilization techniques could affect the characteristics of orthodontic wires. The aim of the present study was to evaluate the effect of steam and dry heat sterilization techniques on load-deflection behavior of five types of β-titanium alloy wires. Materials and Methods: The samples consisted of 30 straight lengths of five types of β-titanium alloy wires: Titanium Molybdenum Alloy (TMA) Low Friction (TMAL), TMA Low Friction Colored (HONE), Resolve (RES), BetaForce (BETA), and BETA CNA (CNA). Thirty wire segments were divided into three groups of 10. Group 1 was the control group and the group 2 samples were sterilized by dry heat in an oven (60 minutes at 160°C) and group 3 by steam in an autoclave (15 minutes at 121°C). Then all the wire samples underwent a three-point bending test in a testing machine to evaluate load-deflection properties. Data was analyzed by repeated measures ANOVA and Scheffé's test (α = 0.05). Results: The results showed that dry heat sterilization significantly increased force levels during both loading and unloading of CNA, BETA and RES and during loading of HONE (P < 0.05). Steam sterilization significantly increased force levels during both loading and unloading of BETA and during unloading of HONE (P < 0.05), with no effects on the load-deflection characteristics of TMAL, CNA and RES (P > 0.05). Conclusion: It appears dry heat sterilization increases stiffness of RES, BETA, CNA and HONE but autoclave sterilization did not have any effect on load-deflection characteristics of most of the β-titanium wires tested, indicating that clinicians who want to provide maximum safety for their patients can autoclave TMAL, RES and CNA before applying them. PMID:23559917

Dendritic and Axonal Wiring Optimization of Cortical GABAergic Interneurons.

PubMed

Anton-Sanchez, Laura; Bielza, Concha; Benavides-Piccione, Ruth; DeFelipe, Javier; Larrañaga, Pedro

2016-10-01

The way in which a neuronal tree expands plays an important role in its functional and computational characteristics. We aimed to study the existence of an optimal neuronal design for different types of cortical GABAergic neurons. To do this, we hypothesized that both the axonal and dendritic trees of individual neurons optimize brain connectivity in terms of wiring length. We took the branching points of real three-dimensional neuronal reconstructions of the axonal and dendritic trees of different types of cortical interneurons and searched for the minimal wiring arborization structure that respects the branching points. We compared the minimal wiring arborization with real axonal and dendritic trees. We tested this optimization problem using a new approach based on graph theory and evolutionary computation techniques. We concluded that neuronal wiring is near-optimal in most of the tested neurons, although the wiring length of dendritic trees is generally nearer to the optimum. Therefore, wiring economy is related to the way in which neuronal arborizations grow irrespective of the marked differences in the morphology of the examined interneurons.

Ultra-high efficiency moving wire combustion interface for on-line coupling of HPLC

PubMed Central

Thomas, Avi T.; Ognibene, Ted; Daley, Paul; Turteltaub, Ken; Radousky, Harry; Bench, Graham

2011-01-01

We describe a 100% efficient moving-wire interface for on-line coupling of high performance liquid chromatography which transmits 100% of carbon in non-volatile analytes to a CO2 gas accepting ion source. This interface accepts a flow of analyte in solvent, evaporates the solvent, combusts the remaining analyte, and directs the combustion products to the instrument of choice. Effluent is transferred to a periodically indented wire by a coherent jet to increase efficiency and maintain peak resolution. The combustion oven is plumbed such that gaseous combustion products are completely directed to an exit capillary, avoiding the loss of combustion products to the atmosphere. This system achieves the near complete transfer of analyte at HPLC flow rates up to 125 μL/min at a wire speed of 6 cm/s. This represents a 30x efficiency increase and 8x maximum wire loading compared to the spray transfer technique used in earlier moving wire interfaces. PMID:22004428

Computers Take Flight: A History of NASA's Pioneering Digital Fly-By-Wire Project

NASA Technical Reports Server (NTRS)

Tomayko, James E.

2000-01-01

An overview of the NASA F-8 Fly-by Wire project is presented. The project made two significant contributions to the new technology: (1) a solid design base of techniques that work and those that do not, and (2) credible evidence of good flying qualities and the ability of such a system to tolerate real faults and to continue operation without degradation. In 1972 the F-8C aircraft used in the program became he first digital fly-by-wire aircraft to operate without a mechanical backup system.

The relationship of lateral anatomic structures to exiting guide pins during femoral tunnel preparation utilizing an accessory medial portal.

PubMed

Farrow, Lutul D; Parker, Richard D

2010-06-01

Anatomic reconstruction of the anterior cruciate ligament through an accessory medial portal has become increasingly popular. The purpose of this study is to describe the relationship of guide pin exit points to the lateral anatomic structures when preparing the anterior cruciate ligament femoral tunnel through an accessory medial portal. We utilized seven fresh frozen cadaveric knees. Utilizing an anteromedial approach, a guide wire was placed into the center of each bundle's footprint. Each guide wire was advanced through the lateral femoral cortex. The guide pins were passed at 90, 110, and 130 degrees of knee flexion. The distances from each guide pin to the closest relevant structures on the lateral side of the knee were measured. At 90 degrees the posterolateral bundle guide pin was closest to the lateral condyle articular cartilage (mean 5.4 +/- 2.2 mm) and gastrocnemius tendon (mean 5.7 +/- 2.1 mm). At 110 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 4.5 +/- 3.4 mm). At 130 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 7.2 +/- 5.5 mm) and lateral collateral ligament (mean 6.8 +/- 2.1 mm). At 90 degrees the anteromedial bundle guide pin was closest to the articular cartilage (mean 2.0 +/- 2.0 mm). At 110 degrees the anteromedial bundle pin was closest to the articular cartilage (mean 7.4 +/- 3.5 mm) and gastrocnemius tendon (mean 12.3 +/- 3.1 mm). At 130 degrees the AM bundle pin was closest to the gastrocnemius tendon (mean 8.2 +/- 3.2 mm) and LCL (mean 15.1 +/- 2.9 mm). Neither guide pin (anteromedial or posterolateral bundle) put the peroneal nerve at risk at any knee flexion angle. At low knee flexion angles the anteromedial and posterolateral bundle guide pins closely approximated multiple lateral structures when using an accessory medial arthroscopic portal. Utilizing higher flexion angles increases the margin of error when preparing both femoral tunnels. During preparation of the anterior cruciate ligament femoral tunnel through an accessory anteromedial portal the tunnels should be drilled in at least 110 degrees of knee flexion in order to move guide pin exit points away from important lateral knee structures.

Electrolyzer assembly method and system

DOEpatents

Swala, Dana Ray; Bourgeois, Richard Scott; Paraszczak, Steven; Buckley, Donald Joseph

2017-05-23

The present techniques provide a novel electrolyzer and methods for welding components of such electrolyzers. The techniques may use conductors, such as resistance wires, placed in paths around the internal structural features and edges of the components. The conductors may be incorporated into the components during manufacture by injection molding, or other molding techniques, or may be tacked or otherwise applied to the surface of the components after manufacture. When current, a field or other excitation is applied to the conductors, the plastic surrounding the wire is melted. If this plastic is in direct contact with an adjoining component, a strong, hermetic seal may be formed between the two components, including the internal structural features.

Hot-wire calibration in subsonic/transonic flow regimes

NASA Technical Reports Server (NTRS)

Nagabushana, K. A.; Ash, Robert L.

1995-01-01

A different approach for calibrating hot-wires, which simplifies the calibration procedure and reduces the tunnel run-time by an order of magnitude was sought. In general, it is accepted that the directly measurable quantities in any flow are velocity, density, and total temperature. Very few facilities have the capability of varying the total temperature over an adequate range. However, if the overheat temperature parameter, a(sub w), is used to calibrate the hot-wire then the directly measurable quantity, voltage, will be a function of the flow variables and the overheat parameter i.e., E = f(u,p,a(sub w), T(sub w)) where a(sub w) will contain the needed total temperature information. In this report, various methods of evaluating sensitivities with different dependent and independent variables to calibrate a 3-Wire hot-wire probe using a constant temperature anemometer (CTA) in subsonic/transonic flow regimes is presented. The advantage of using a(sub w) as the independent variable instead of total temperature, t(sub o), or overheat temperature parameter, tau, is that while running a calibration test it is not necessary to know the recovery factor, the coefficients in a wire resistance to temperature relationship for a given probe. It was deduced that the method employing the relationship E = f (u,p,a(sub w)) should result in the most accurate calibration of hot wire probes. Any other method would require additional measurements. Also this method will allow calibration and determination of accurate temperature fluctuation information even in atmospheric wind tunnels where there is no ability to obtain any temperature sensitivity information at present. This technique greatly simplifies the calibration process for hot-wires, provides the required calibration information needed in obtaining temperature fluctuations, and reduces both the tunnel run-time and the test matrix required to calibrate hotwires. Some of the results using the above techniques are presented in an appendix.

Wiring Economy of Pyramidal Cells in the Juvenile Rat Somatosensory Cortex

PubMed Central

Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier

2016-01-01

Ever since Cajal hypothesized that the structure of neurons is designed in such a way as to save space, time and matter, numerous researchers have analyzed wiring properties at different scales of brain organization. Here we test the hypothesis that individual pyramidal cells, the most abundant type of neuron in the cerebral cortex, optimize brain connectivity in terms of wiring length. In this study, we analyze the neuronal wiring of complete basal arborizations of pyramidal neurons in layer II, III, IV, Va, Vb and VI of the hindlimb somatosensory cortical region of postnatal day 14 rats. For each cell, we search for the optimal basal arborization and compare its length with the length of the real dendritic structure. Here the optimal arborization is defined as the arborization that has the shortest total wiring length provided that all neuron bifurcations are respected and the extent of the dendritic arborizations remain unchanged. We use graph theory and evolutionary computation techniques to search for the minimal wiring arborizations. Despite morphological differences between pyramidal neurons located in different cortical layers, we found that the neuronal wiring is near-optimal in all cases (the biggest difference between the shortest synthetic wiring found for a dendritic arborization and the length of its real wiring was less than 5%). We found, however, that the real neuronal wiring was significantly closer to the best solution found in layers II, III and IV. Our studies show that the wiring economy of cortical neurons is related not to the type of neurons or their morphological complexities but to general wiring economy principles. PMID:27832100

Wiring Economy of Pyramidal Cells in the Juvenile Rat Somatosensory Cortex.

PubMed

Anton-Sanchez, Laura; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier

2016-01-01

Ever since Cajal hypothesized that the structure of neurons is designed in such a way as to save space, time and matter, numerous researchers have analyzed wiring properties at different scales of brain organization. Here we test the hypothesis that individual pyramidal cells, the most abundant type of neuron in the cerebral cortex, optimize brain connectivity in terms of wiring length. In this study, we analyze the neuronal wiring of complete basal arborizations of pyramidal neurons in layer II, III, IV, Va, Vb and VI of the hindlimb somatosensory cortical region of postnatal day 14 rats. For each cell, we search for the optimal basal arborization and compare its length with the length of the real dendritic structure. Here the optimal arborization is defined as the arborization that has the shortest total wiring length provided that all neuron bifurcations are respected and the extent of the dendritic arborizations remain unchanged. We use graph theory and evolutionary computation techniques to search for the minimal wiring arborizations. Despite morphological differences between pyramidal neurons located in different cortical layers, we found that the neuronal wiring is near-optimal in all cases (the biggest difference between the shortest synthetic wiring found for a dendritic arborization and the length of its real wiring was less than 5%). We found, however, that the real neuronal wiring was significantly closer to the best solution found in layers II, III and IV. Our studies show that the wiring economy of cortical neurons is related not to the type of neurons or their morphological complexities but to general wiring economy principles.

Development of automatic pre-tracking system for fillet weld based on laser trigonometry

NASA Astrophysics Data System (ADS)

Shen, Xiaoqin; Yu, Fusheng

2005-01-01

In this paper, an automatic fillet weld pre-tracking system for welding the work piece of lorry back boards with several bend in haul automobile is developed basing on laser trigonometry. The optical measuring head based on laser-PSD trigonometry is used as position sensor. It is placed in front of the traveling direction of welding wire to get the distances from welding wire to the two side boards of the welding lines, upper board and bottom board of the fillet weld respectively. A chip of AT89S52 is used as the micro controller in this system. The AC servomotors, ball-screws and straight guide rails constitute the sliding table to take welding wire move. The laser-PSD sensors pass through the vertical board, upper board and bottom board of the fillet weld when welding wire moves and then get the distance. The laser-PSD sensors output the analog signals. After A/D conversion, the digital signal is input into AT89S52 and calculated. Then the information of the position and lateral deviation of the welding wire when welding a certain position are gotten to control welding wires. So the weld pre-tracking for welding the work piece with long distance and large bend in haul automobile is realized. The position information is input into EEPROM to be saved for short time after handled by AT89S52. The information is as the welding position information as well as the speed adjusting data of the welding wire when it welds the several bend of the work piece. The practice indicates that this system has high pre-tracking precision, good anti-disturb ability, excellent reliability, easy operating ability and good adaptability to the field of production.

Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deadrick, F.J.; Griffith, L.V.

1990-08-17

Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that acceleratormore » is magnetically aligned to within {approximately}{plus minus}200 microns. 3 refs., 8 figs.« less

Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

NASA Astrophysics Data System (ADS)

Mitchard, D.; Clark, D.; Carr, D.; Haddad, A.

2016-08-01

A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kos, Sebastian, E-mail: skos@gmx.de; Guerke, Lorenz; Jacob, Augustinus L.

Purpose: This study was designed to demonstrate the applicability of a combined needle-based re-entry catheter and 'cheese-wire' technique for fenestration of abdominal aortic dissection membranes. Methods: Four male patients (mean age: 65 years) with acute complicated aortic type B dissections were treated at our institution by fenestrating the abdominal aortic dissection membrane using a hybrid technique. This technique combined an initial membrane puncture with a needle-based re-entry catheter using a transfemoral approach. A guidewire was passed through the re-entry catheter and across the membrane. Using a contralateral transfemoral access, this guidewire was then snared, creating a through-and-through wire access. Themore » membrane was then fenestrated using the cheese-wire maneuver. Results: We successfully performed: (a) membrane puncture; (b) guidewire passage; (c) guidewire snaring; and (d) cheese-wire maneuver in all four cases. After this maneuver, decompression of the false lumen and acceptable arterial inflow into the true lumen was observed in all cases. The dependent visceral arteries were reperfused. In one case, portions of the fenestrated membrane occluded the common iliac artery, which was immediately and successfully stented. In another case, long-standing intestinal hypoperfusion before the fenestration resulted in reperfusion-related shock and intraoperative death of the patient. Conclusions: The described hybrid approach for fenestration of dissection membranes is technically feasible and may be established as a therapeutic method in cases with a complicated type B dissection.« less

Imaging-Assisted Large-Format Breast Pathology: Program Rationale and Development in a Nonprofit Health System in the United States

PubMed Central

Tucker, F. Lee

2012-01-01

Modern breast imaging, including magnetic resonance imaging, provides an increasingly clear depiction of breast cancer extent, often with suboptimal pathologic confirmation. Pathologic findings guide management decisions, and small increments in reported tumor characteristics may rationalize significant changes in therapy and staging. Pathologic techniques to grossly examine resected breast tissue have changed little during this era of improved breast imaging and still rely primarily on the techniques of gross inspection and specimen palpation. Only limited imaging information is typically conveyed to pathologists, typically in the form of wire-localization images from breast-conserving procedures. Conventional techniques of specimen dissection and section submission destroy the three-dimensional integrity of the breast anatomy and tumor distribution. These traditional methods of breast specimen examination impose unnecessary limitations on correlation with imaging studies, measurement of cancer extent, multifocality, and margin distance. Improvements in pathologic diagnosis, reporting, and correlation of breast cancer characteristics can be achieved by integrating breast imagers into the specimen examination process and the use of large-format sections which preserve local anatomy. This paper describes the successful creation of a large-format pathology program to routinely serve all patients in a busy interdisciplinary breast center associated with a community-based nonprofit health system in the United States. PMID:23316372

Direct peroral cholangioscopy using an ultraslim upper endoscope for biliary lesions.

PubMed

Omuta, Shigefumi; Maetani, Iruru; Ukita, Takeo; Nambu, Tomoko; Gon, Katsushige; Shigoka, Hiroaki; Saigusa, Yoshinori; Saito, Michihiro

2014-02-01

The development of direct peroral cholangioscopy (DPOC) using an ultraslim endoscope simplifies biliary cannulation. The conventional techniques are cumbersome to perform and require advanced skills. The recent introduction of the guidewires and balloons has improved the therapeutic outcomes. Here we describe an effective and easier method for performing DPOC using an ultraslim upper endoscope. Indications for DPOC were the presence of stones on follow-up of patients who had previously undergone complete sphincteroplasty, including endoscopic sphincterotomy or endoscopic papillary large balloon dilatation. Fifteen patients underwent DPOC. An ultraslim endoscope was inserted perorally and was advanced into the major papilla. The ampulla of Vater was visualized by retroflexing the endoscope in the distal second portion of the duodenum, and then DPOC was performed using a wire-guided cannulation technique with an anchored intraductal balloon catheter. One patient failed in the treatment due to looping of the endoscope in the fornix of the stomach. Fourteen (93.3%) were successfully treated with our modified DPOC technique. Only one patient (6.7%) experienced an adverse event (pancreatitis) who responded well to conservative management. Residual stones of the common bile duct were completely removed in 3 patients. The modified method of DPOC is simple, safe and easy to access the bile duct.