Device-related Issues Research Articles

The social implications of location-based services: an observational study of users

Location-based services (LBS) are applications capable of utilising the position of a device, and its user, in the provision of a value-added service. With such applications comes the ability for an individual's location to be monitored either willingly or covertly by others, thus introducing a set of challenges from a social perspective. This article reports on the results of an observational study that required participants to maintain a digital location chronicle – global positioning system data log, daily diary entry and personal reflection – over a 2-week period. The primary aim of this exercise was for participants to observe, reflect and record their experiences during and at the completion of the participant observation, in order to reveal the ensuing collective implications. This study is a further research based on previous work concerning LBS user attitudes (Abbas 2010), and as such concentrates on the Gen-Y or young adult consumer group. This investigation considers additionally the importance of LBS within a social context, whereby participants are prompted to reflect on their willingness to be monitored or tracked by a partner, parent, friend, employer and/or stranger. The results are presented in terms of the social implications. The dominant themes in the respective relationship categories are presented in each context. It was noted that participants’ readiness to grant access to their location information is heavily dependent on the amount of trust existing within a specific relationship, whether there is a perceived privacy threat, the amount of control a participant wishes to maintain, and if there is concern in relation to personal security and safety being compromised. Additional technological and device-related issues were also observed.

A Preclinical Study of the Safety and Efficacy of Occlusin™ 500 Artificial Embolization Device in Sheep

This study evaluated the safety, effectiveness, and biodegradation of a new embolic agent, Occlusin™ 503 Artificial Embolization Device (OCL 503). The agent consists of biodegradable poly-lactic-co-glycolic acid microspheres (150-212 μm) coated with type I bovine collagen and was compared with Embosphere® Microspheres (300-500 μm) in this controlled study of uterine artery embolization (UAE) in sheep. Unilateral UAE was performed in 32 adult ewes randomly assigned. Vessels were embolized to effective stasis. The cohort was divided into four groups, which were sacrificed at 1, 3, 6, and 12 months. Both agents were 100% effective in achieving stasis. At 6 months, all OCL 503-treated arteries were occluded, the microspheres degraded with time, and at 12 months all four animals examined demonstrated recanalization. OCL 503 was found in the untreated uterine artery in one animal with no other evidence of non target embolization. In the Embosphere-treated group, all vessels remained occluded and microspheres were detected in the contralateral uterine artery in 6 of 15 examined vessels and in 10 vaginal, 2 ovarian, and 1 vesical artery. No procedural-related complications were seen in either group. OCL 503 is as effective an embolic agent as Embosphere® Microspheres when embolizing ovine uterine arteries and resorbs with time, allowing recanalization of the treated arteries. No device-related issues or adverse events were observed.

Development of the Satisfaction Measure of the Injection of Growth Hormone (GH) Therapy (SMIGHTY TM) Questionnaire

Development of the Satisfaction Measure of the Injection of Growth Hormone (GH) Therapy (SMIGHTY TM) Questionnaire

Effects of cochlear implants: a qualitative study

This qualitative study aimed to gain a deeper insight into the effects of cochlear implants on recipients' lives, as perceived by the recipients themselves. To obtain this insight, we used four open-ended questions. We invited 107 adult patients from two Norwegian implant centres. Of these, 74 returned completed questionnaires (69%). Recipients perceived that they had got 'A new life' with the implant. Contributing to this global category of effects were four other categories. These concerned subjects' interactions with the world around them, experience of themselves, ability to hear the world around them and finally certain device-related issues. Overall, psychological well-being was improved. The questionnaire described might prove a useful tool in the follow-up of patients.

Effects of cochlear implants: a qualitative study

This qualitative study aimed to gain a deeper insight into the effects of cochlear implants on recipients' lives, as perceived by the recipients themselves. To obtain this insight, we used four open-ended questions. We invited 107 adult patients from two Norwegian implant centres. Of these, 74 returned completed questionnaires (69%). Recipients perceived that they had got ‘A new life’ with the implant. Contributing to this global category of effects were four other categories. These concerned subjects' interactions with the world around them, experience of themselves, ability to hear the world around them and finally certain device-related issues. Overall, psychological well-being was improved. The questionnaire described might prove a useful tool in the follow-up of patients. Copyright © 2009 John Wiley & Sons, Ltd.

Survivorship of coflex Interlaminar-Interspinous Implant

Background The purpose of this study was to determine the indications for implantation of the coflex device (Paradigm Spine, LLC, New York, New York), assess long-term complications, and evaluate the long-term clinical outcomes of patients. Methods A total of 127 patients underwent placement of a coflex implant for various indications by one orthopaedic spine surgeon. The mean follow-up was 6.3 years. The original indications for implantation were determined based upon the data provided in the case report forms. Preoperatively and postoperatively, patients were asked to grade their low-back and leg pain using the visual analog scale (VAS) and the pain severity scale: no pain (0), mild pain (1), moderate pain (2), or severe pain (3). Patients were queried about their satisfaction with the surgical procedure. Follow-up radiographs were taken to determine any device-related issues. Results The most prevalent diagnoses for implantation were spinal stenosis (19.7%) and spinal stenosis with lumbar disc herniation (35.4%). The mean severity of low-back pain was decreased by 33% (from moderate to mild) at the 2-year follow-up ( P < .001) and at the 5-year follow-up (from moderate to mild, P < .001). The mean severity of leg pain was decreased by 66% (from severe to mild) at the 2-year follow-up ( P < .001) and at the 5-year follow-up (from severe to mild, P < .001). At the mean follow-up period of 6.3 years, a patient satisfaction query demonstrated that 7% were unsatisfied, 46% were satisfied, and 46% were very satisfied with their clinical outcome. Based on the follow-up radiographs, 92 of patients had no device-related issues and 8% had device-related issues. Conclusion The data provided have demonstrated that the coflex implant provides pain relief for patients with low-back pain and leg pain. The most common indications for implantation were spinal stenosis and spinal stenosis with lumbar disc herniation. There were very few device-related complications. Clinical Significance Using coflex is a safe and viable option in the selection of instrumentation for spinal stabilization.

Survivorship of coflex Interlaminar-Interspinous Implant.

BackgroundThe purpose of this study was to determine the indications for implantation of the coflex device (Paradigm Spine, LLC, New York, New York), assess long-term complications, and evaluate the long-term clinical outcomes of patients.MethodsA total of 127 patients underwent placement of a coflex implant for various indications by one orthopaedic spine surgeon. The mean follow-up was 6.3 years. The original indications for implantation were determined based upon the data provided in the case report forms. Preoperatively and postoperatively, patients were asked to grade their low-back and leg pain using the visual analog scale (VAS) and the pain severity scale: no pain (0), mild pain (1), moderate pain (2), or severe pain (3). Patients were queried about their satisfaction with the surgical procedure. Follow-up radiographs were taken to determine any device-related issues.ResultsThe most prevalent diagnoses for implantation were spinal stenosis (19.7%) and spinal stenosis with lumbar disc herniation (35.4%). The mean severity of low-back pain was decreased by 33% (from moderate to mild) at the 2-year follow-up (P < .001) and at the 5-year follow-up (from moderate to mild, P < .001). The mean severity of leg pain was decreased by 66% (from severe to mild) at the 2-year follow-up (P < .001) and at the 5-year follow-up (from severe to mild, P < .001). At the mean follow-up period of 6.3 years, a patient satisfaction query demonstrated that 7% were unsatisfied, 46% were satisfied, and 46% were very satisfied with their clinical outcome. Based on the follow-up radiographs, 92 of patients had no devicerelated issues and 8% had device-related issues.ConclusionThe data provided have demonstrated that the coflex implant provides pain relief for patients with low-back pain and leg pain. The most common indications for implantation were spinal stenosis and spinal stenosis with lumbar disc herniation. There were very few device-related complications.Clinical SignificanceUsing coflex is a safe and viable option in the selection of instrumentation for spinal stabilization.

Influence of IUD perceptions on method discontinuation

Objective The study was conducted to assess how misbeliefs and fears about intrauterine contraceptive devices (IUDs) can influence the rate of early discontinuation of this method. Study Design This is a prospective survey conducted at the Family Planning Clinic at Al-Habibia Maternity Teaching Hospital (Baghdad, Iraq). Two hundred women presenting to the family planning clinic with requests for premature IUD removal were administered a structured questionnaire to ascertain demographic information and reasons for removal request. Careful and sympathetic questioning was essential in order to obtain correct information. The data were analyzed using descriptive and inferential statistics. Results Slightly over half of the women (52.8%) gave only one reason for requesting removal, while the remaining (47.5%) women had two or three complaints. Side effects were the principal reason for request for removal in both groups (45.7% and 42.6%). In the group that offered only one reason, IUD side effects, device-related issues, fears about the device and pregnancy or seeking pregnancy were the reported reasons. In the group that offered more than one reason, each had two or three complaints. IUD side effects and fears about the device were the most prevalent (42.6% and 41.8%, respectively); these fears and perceptions were reported more frequently among younger users and among those requesting early removal. Conclusion Fears and misbeliefs about IUD contributed to discontinuation of use in almost half of the women requesting IUD removal. These elements were more common among younger women and, noticeably, among those who requested early removal.

Chronic in-vivo experience with an endoscopically delivered and retrieved duodenal-jejunal bypass sleeve in a porcine model

The role of duodenal bypass as an underlying mechanism of action in gastric bypass surgery has received considerable attention. We report the initial feasibility study of a totally endoscopically delivered and retrieved duodenal-jejunal bypass sleeve in a chronic porcine model. The implant consists of a 60-cm fluoropolymer sleeve that is endoscopically deployed via a coaxial catheter system into the jejunum and fixed in the proximal duodenum with a Nitinol anchor. The system creates a proximal biliopancreatic diversion. Six female Yorkshire pigs were endoscopically implanted; all survived. Four animals (group 1) were slated to survive 90 days, two animals (group 2) for 120 days, and three animals (group 3) underwent sham endoscopy and were survived 120 days. Animals were fed standard dry pig chow 0.5 kg three times daily. Data points included daily general health, weekly weight, serum blood tests (complete blood count, amylase, lipase, liver function tests), and monthly evaluation of anchor/sleeve position/patency by fluoroscopy and endoscopy. Following the in-vivo period, the devices were endoscopically removed and the animals were sacrificed. Duodenal and jejunal tissue samples were assessed histologically. All six test animals were implanted and explanted without significant adverse events. In group 1, the first animal had no device-related issues. The second animal had a pivoted anchor requiring repositioning at day 63. That animal had no further difficulties. The third animal had an incidental partial rotation of the anchor noted at the 90 day explantation. The fourth animal was incidentally implanted with a crossover of the anchor struts, which was endoscopically corrected on day 14. However, on day 20 the animal had persistent vomiting, and the device was explanted. Both group 2 animals survived 120 days. One animal had a partially rotated anchor but was asymptomatic. The average weight gain between test and sham groups was 0.23 kg/day and 0.42 kg/day, respectively (p = 0.01). A totally endoscopic and reversible bypass of the duodenum and proximal jejunum has been achieved for 90-120 days. Initial experience suggests patency of the sleeve and acceptable tissue response. Reduced weight gain in the test animals suggests device efficacy. Further investigation is warranted.

Suture Anchors and Tacks for Shoulder Surgery, Part II

The use of suture anchors and tacks around the shoulder requires a thorough knowledge of the proper use of the devices and how to insert them. Although typically not technically demanding, suture anchors and tacks can present unique and frustrating challenges to the patient and the surgeon. These challenges can occur whether the procedure is performed via an open or arthroscopic approach, but knowledge of the potential challenges may optimize the surgical result and prevent complications. Complications can be categorized as technique-related or device-related issues (mechanical or biologic failure). Techniquerelated complications include problems with the delivery systems, anchor malpositioning, and suture management issues, such as knots not sliding. Device-related complications include implant fracture, migration secondary to poor fixation, synovitis from implant degradation, and osteolysis. This review describes the prevention of these and other complications, addresses the indications or need for intervention, and suggests potential solutions when intervention is indicated.

Magnetic resonance imaging-guided vascular interventions.

Magnetic resonance imaging (MRI), which provides superior soft-tissue imaging and no known harmful effects, has the potential as an alternative modality to guide various medical interventions. This review will focus on MR-guided endovascular interventions and present its current state and future outlook. In the first technical part, enabling technologies such as developments in fast imaging, catheter devices, and visualization techniques are examined. This is followed by a clinical survey that includes proof-of-concept procedures in animals and initial experience in human subjects. In preclinical experiments, MRI has already proven to be valuable. For example, MRI has been used to guide and track targeted cell delivery into or around myocardial infarctions, to guide atrial septal puncture, and to guide the connection of portal and systemic venous circulations. Several investigational MR-guided procedures have already been reported in patients, such as MR-guided cardiac catheterization, invasive imaging of peripheral artery atheromata, selective intraarterial MR angiography, and preliminary angioplasty and stent placement. In addition, MR-assisted transjugular intrahepatic portosystemic shunt procedures in patients have been shown in a novel hybrid double-doughnut x-ray/MRI system. Numerous additional investigational human MR-guided endovascular procedures are now underway in several medical centers around the world. There are also significant hurdles: availability of clinical-grade devices, device-related safety issues, challenges to patient monitoring, and acoustic noise during imaging. The potential of endovascular interventional MRI is great because as a single modality, it combines 3-dimensional anatomic imaging, device localization, hemodynamics, tissue composition, and function.

Lumbar spine arthroplasty using the ProDisc II

The ProDisc was developed by Thierry Marnay, a French orthopedic surgeon, in the late 1980s. Marnay and his associate implanted ProDiscs into 64 patients from 1990 to 1993. Demonstrating remarkable intellectual restraint, he let this cohort of patients “incubate” so he could see their progress before performing any additional implantations. In 1998, 61 of these patients were still alive, and 58 (95%) of them were available for a thorough follow-up evaluation. No device-related safety issues were identified during this review, and 93% of these patients were satisfied with their implants. This unique and strong data set led to an unusually rapid Food and Drug Administration (FDA) approval for an Investigational Device Exemption study in the United States, prospectively comparing implantation of a ProDisc with a 360-degree fusion, with both single- and double-level study arms. This article represents data on the first 78 patients with at least 6-month follow-up, with 54 of these patients also having 1-year follow-up, enrolled in a prospective randomized FDA study evaluating the safety and efficacy of ProDisc II versus control, a 360-degree lumbar spinal fusion. Data were collected preoperatively at 6 weeks, 3 months, 6 months and 1 year postoperatively. Visual analog scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ) and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, recreational status and ambulatory status. At 6-month follow-up, there were there were 55 ProDisc patients and 23 who underwent fusion. Twenty-five of these patients had two-level surgery. Estimated blood loss (ProDisc, 103 cc, vs fusion, 213 cc) and operative time (ProDisc, 90 minutes, vs fusion, 232 minutes) were significantly different (p<.01). Hospital stays were shorter (ProDisc, 2.24 days, vs fusion, 3.26 days [p<.01]) for ProDisc patients. There was a significant reduction in the ODQ scores from preoperative values in both ProDisc and fusion groups. Similarly, there was a significant reduction for both groups in VAS scores from before to after surgery. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (p=.08), which became more pronounced (although still not statistically significant) at 1 year. Flexion and lateral bend range of motion was significantly improved in ProDisc patients compared with the fusion group (p=.02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.

Left ventricular assist devices as destination therapy for end-stage heart failure

Clinical scenario You admit a 67-year-old man with a history of ischemic cardiomyopathy, 3-vessel coronary artery bypass graft surgery, and a left ventricular ejection fraction of 25% with New York Heart Association (NYHA) Class IV heart failure symptoms. The patient states that over the past few months he has had a gradual decline in his functional status despite maximal medical therapy. He already has a biventricular implantable cardioverter/defibrillator (ICD) in place, and is transferred to your service with a blood pressure of 88/60, on dopamine and dobutamine drips, with a sodium of 120 and a creatinine of 0.9. His coronary anatomy is not suitable for revascularization. Because of progressive diabetes with end organ damage (retinopathy) and his advanced age, he is not considered an ideal transplant candidate. You wonder how he might fare with destination left ventricular assist device (LVAD) therapy. Literature search Combining the keywords heart failure (heart failure, congestive), heart assist devices, and survival analysis, Medline provides 27 references. You choose the following article: Rose EA, Gelijns AC, Moskowitz AJ, et al. Long-term use of a left ventricular assist device for end-stage heart failure. For the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) Study Group. N Engl J Med 2001;345:1435 43. Question What is the overall survival and quality of life for patients receiving destination LVAD therapy? Design The study was a randomized, unblinded trial of patients with Class IV heart failure who were not transplant candidates and who continued with maximal medical therapy or received destination LVAD therapy with a HeartMate device (Thoratec, Pleasanton, Calif). Patients A total of 129 patients with NYHA Class IV heart failure who were not candidates for cardiac transplantation were enrolled in the study. Patients had been treated with angiotensin-converting enzyme inhibitors, diuretics, and digoxin, had a left ventricular ejection fraction ≤25%, and a maximal oxygen uptake ≤12 mL/kg/min or the need for continuous inotropic support. Patients were allowed to remain on β-blockers if they had received them for at least 60 of the 90 days before randomization. The patients had an average age of 68 years in the medical therapy group and 66 years in the LVAD group. Intervention Patients were randomized to continue with maximal medical therapy or receive the HeartMate left ventricular assist device. Main outcome measures The primary end point was death from any cause. Secondary end points included serious adverse events, the number of days spent in the hospital, quality of life, depression, and functional status. Main results At 1 year, 25% of patients in the medical therapy group were still alive, compared with 52% of patients in the LVAD group (P =.002). Median survival was 150 days in the medically-treated group compared with 408 days in the LVAD group. At 2 years, 8% of the medically-treated group was still alive compared with 23% of the LVAD group (P =.09). Whereas the medically-treated group died primarily of progressive pump failure, patients in the LVAD group died from sepsis (41% of deaths) or device failure (17%). Quality of life was significantly better in the LVAD group, with higher scores on the SF-36 physical scale (46 vs 21, P =.01), the SF-36 emotional scale (64 vs 17, P =.03), the Beck Depression Inventory (8 vs 13, P =.04), and lower NYHA class (II vs IV, P <.001). Commentary Destination LVAD therapy provides improved survival and quality of life for patients with Class IV heart failure compared with maximal medical therapy. 1 Although survival was longer at 1 year with the LVAD, by 2 years most patients in both arms of the study had died. The patients in the LVAD arm of this trial died primarily from device-related issues such as mechanical failure, sepsis, and stroke, all of which are potentially modifiable with technical improvements. In fact

Proceedings of the 6th International Workshop on Expert Evaluation and Control of Compound Semiconductor Materials and Technology (EXMATEC'02)

The scientific scope of EXMATEC encompasses a broad range of compound semiconductor device-related issues as well as materials related problems, in both cases emphasizing fabrication, processing and characterization. The conference presentations were grouped into eight sections: – Growth: Process monitoring, improving of individual steps – Gallium nitride and related compounds: materials and devices – Characterization, identification and reduction of defects in epitaxial layers – High frequency and high power devices: material related issues – Optoelectronic materials and devices, reliability issues – Quantum dots, nanostructures, low-dimensional systems – Characterization techniques – New frontiers: materials, technologies, structures, devices

Ultrathin high-K metal oxides on silicon: processing, characterization and integration issues

An overview of our recent work on ultrathin (<100 Å) films of metal oxides deposited on silicon for advanced gate dielectrics applications will be presented. Data on ultrathin Al 2O 3, ZrO 2, HfO 2, and Y 2O 3 will be shown to illustrate the complex processing, integration and device-related issues for high dielectric constant (‘high-K’) materials. Both physical and electrical properties, as well as the effects of pre- and post-deposition treatments will be discussed.

Characterization of semiconductor laser diodes by beam injection techniques

This paper illustrates the application of microscopy techniques to address material, processing, and device-related issues encountered in the development of laser diodes. General comments are made concerning local characterization of laser diodes, and issues related to laser reliability are addressed. An extensive investigation is presented, showing how microscopy techniques can facilitate the building of modern devices. The examples cited include recent data published by various authors as well as the author's own work on quantum well ridge-type InGaP/AlGalnP/AlGaAs red emitting lasers, GaAs/AlGaAs lasers, strained InGaAs/AlGaAs 980 nm lasers, and GaAs/AlGaAs lasers with dry-etched mirrors.

Materials issues underlying compound semiconductor devices

In this paper we review the special properties of compound semiconductors which make them attractive for device applications and discuss current research issues concerning the propessing of III–V compounds and heterojunction multilayers. The novel electronic properties available in III–V alloys are discussed, including special new phenomena observed in heterostructure multilayers and strained-layer superlattices. Device-related processing issues are outlined, including novel growth technique, insulator interfaces, Schottky barrier and ohmic contact formation, sample preparation, and implantation and annealing.