Home About us Contact
|
Home About us Contact | ||
|
|
||
Device Failure (device + failure)
Selected AbstractsExchanging dual-lumen central venous catheters: How I do itJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 2 2007I Chaitowitz Summary The management of a blocked long-term central venous catheter has traditionally been removal and re-siting, even when device failure is not associated with venous thrombosis or sepsis. It is not possible to ,railroad' a split dual-lumen central venous catheter down a long tortuous s.c. tunnel. Our exchange technique was designed to salvage the tunnel and venous access site in a long-term catheter that has had uncomplicated primary device failure. In this technique we divide the dual-lumen catheter and secure the venous access site and the s.c. tunnel with separate peel-away sheaths. The new catheter is then introduced in the conventional manner through the two peel-away sheaths, which are then removed. The key advantage of the technique is that it preserves one of the few central venous access sites available. This article describes exchange of an internal jugular catheter, but the same technique is applicable to subclavian catheters. [source] Inability to Communicate with ICDs: An Underreported Failure ModePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2001MARK L. BLITZER BLITZER, M.L., et al.: Inability to Communicate with ICDs: An Underreported Failure Mode. The inability to perform telemetry on an ICD may have many potential causes. We report three recently identified cases where such a finding was indicative of unexpected device failure. Two of these cases involved identical failure mechanisms resulting from arcing of current within the high voltage hybrid. This placed the device into a high current state that caused rapid and complete battery depletion. There were no company alerts issued regarding this systematic problem. A multicenter arrhythmia device/lead database would be extremely useful in providing timely and unbiased information concerning device problems. [source] Random, systematic, and common cause failure: How do you manage them?,PROCESS SAFETY PROGRESS, Issue 4 2006Michela Gentile Abstract A safety instrumented system (SIS) may fail to operate as desired when one or more of its devices fail due to random, systematic, and common cause events. IEC 61511 (ANSI/ISA 84.00.01,2004) stresses the importance of minimizing the propagation of device failure into system failure through design, operating, inspection, and maintenance practices. To fully understand the lifecycle requirements, it is first necessary to understand the types of failures and their potential effects on the SIS. Although several technical standards and other specialized literature address the topic, it is still a "fuzzy" matter, subject to misunderstanding and discussion. IEC 61511 Clause 11.9 requires that the SIL be verified using quantitative analysis, such as reliability block diagrams, fault tree analysis, and Markov modeling. This analysis includes only those dangerous failures that are random in nature. Common cause failures may or may not be included in the verification calculation depending on whether they exhibit random or systematic behavior. Any personnel assigned responsibility for verifying the SIL should understand each failure type and the strategies that can be used against it. Consequently, this article provides an overview of random, systematic, and common cause failures and clarifies the differences in their management within IEC 61511. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source] Incidence and indications for revision cochlear implant surgery in adults and children,THE LARYNGOSCOPE, Issue 1 2009Kevin D. Brown MD Abstract Objectives/Hypothesis: To identify the incidence of and common causes for cochlear implant revision. Study Design: Retrospective case series. Methods: Operative records were reviewed for all cases of revision cochlear implantation from 1992 to 2006. The causes for reimplantation were classified as hard device failure, soft device failure, exposure/infection, receiver/stimulator migration, and electrode migration. Manufacturers' failure analysis of explanted devices was likewise determined. Results: Eight hundred and six cochlear implants were performed during the study period including 44 (5.5%) revision procedures. The revision rate was 7.3% for children and 3.8% for adults and reached statistical significant difference. The most common reasons for revision were device failure (78%; 55% hard failure, 23% soft failure) followed by electrode migration (9%) and receiver/stimulator migration (7%). Manufacturers' analysis of failed devices revealed loss of hermetic seal and cracked cases to be the most common causes of failure. Bench analysis of 5/10 explanted devices that were soft failures demonstrated identifiable device defects. Conclusions: Revision cochlear implant surgery is an infrequent occurrence. Its incidence appears to be higher in children than in adults, although in this series does not appear to be due to increased wound complications, infections, or trauma. Explanted implants that have soft failure as the etiology may have demonstrable defects on bench testing. Laryngoscope, 119:152,157, 2009 [source] Assessment of Intraoperative Safety in Transoral Robotic Surgery,THE LARYNGOSCOPE, Issue 2 2006Neil G. Hockstein MD Abstract Introduction: Robotic technology has been safely integrated into thoracic and abdominopelvic surgery, and the early experience has been very promising with very rare complications related to robotic device failure. Recently, several reports have documented the technical feasibility of transoral robotic surgery (TORS) with the daVinci Surgical System. Proposed pharyngeal and laryngeal applications include radical tonsillectomy, base-of-tongue resection, supraglottic laryngectomy, and phonomicrosurgery. The safety of transoral placement of the robotic endoscope and instruments has not been established. Potential risks specific to the transoral use of the surgical robot include facial skin laceration, tooth injury, mucosal laceration, mandible fracture, cervical spine fracture, and ocular injury. We hypothesize that these particular risks of transoral surgery are similar with robotic assistance compared with conventional transoral surgery. Methods: To test this hypothesis, we attempted to intentionally injure a human cadaver with the daVinci Surgical System by impaling the facial skin and pharyngeal and laryngeal mucosa with the robotic instruments and endoscope. We also attempted to extract or fracture teeth and fracture the cadaver's mandible and cervical spine by applying maximal pressure and torque with the robotic arms. Experiments were documented with still and video photography. Results: Impaling the cadaver's skin and mucosa resulted in only superficial lacerations. Tooth, mandible, and cervical spine fracture could not be achieved. Conclusions: Initial experiments performing TORS on a human cadaver with the daVinci Surgical System demonstrate a safety profile similar to conventional transoral surgery. Additionally, we discuss several strategies to increase patient safety in TORS. [source] Feasibility and Initial Results of an Internet-Based Pacemaker and ICD Pulse Generator and Lead RegistryPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2001ROBERT HAUSER HAUSER, R., et al.: Feasibility and Initial Results of an Internet-Based Pacemaker and ICD Pulse Generator and Lead Registry. The medical community has no independent source of timely information regarding the performance of pacemaker and ICD pulse generators and leads. Accordingly, the authors established an Internet-based registry of pacemaker and ICD pulse generator and lead failures (www.pacerandicregistry.com). During the first year, they found three previously unreported device problems that were promptly communicated to the participants. Of the failures reported, 11% of ICD and 10% of pacemaker pulse generator failures were heralded by signs other than the expected elective replacement indicator (ERI). Average ICD battery longevity was 4.0 ± 0.7 years, and average dual chamber pacemaker battery longevity was 6.8 ± 2.6 years. Disrupted insulation accounted for 54% of pacemaker and 29% of ICD lead failures. Compared to pacemaker pulse generator and lead failure, ICD device failures were more likely to cause severe clinical consequences. In conclusion, an Internet-based registry is feasible and capable of providing timely data regarding the signs, causes, and clinical consequences of pacemaker and ICD failures. [source] Long-Term Performance of Clarion 1.0 Cochlear Implant Users,THE LARYNGOSCOPE, Issue 7 2007Chad V. Ruffin BS Abstract Objective/Hypothesis: To evaluate the long-term performance of adult Clarion 1.0 cochlear implant users. Study Design: This was a retrospective, longitudinal study evaluating word discrimination in quiet for 31 adult cochlear implant patients with preimplantation sentence scores of less than 10%. Methods: The length of the study was 135 months with a mean follow-up length of 93 (median, 96) months. For the duration of the study, all subjects used the Clarion 1.0 cochlear implant with speech processors programmed for the use of the continuous interleaved sampling strategy. Results: There was no significant growth or decline in speech perception after 24 months postimplantation unless adverse medical events were experienced. Age at implantation was significantly and substantially negatively correlated (,11% word score per decade, r = 0.68) with most recent score, maximum score, time to maximum score, range of performance, 24- to 130-month mean score, and for any longitudinal data point tested: 3 to 6 months, 6 months, 1 year, 2 years, 5 years, and 10 years. There were no age-related declines in performance. There were no observed correlations between duration of deafness and any of the variables listed above. Conclusions: The lack of correlation between duration of deafness and performance in a cohort without residual hearing suggests the presence of a strong correlation between age and speech performance with a cochlear implant. That the cochlear implant is a safe therapy for the treatment of profound deafness is supported by the stability of scores through the 10-year study period as well as a zero rate of device failures or explantation. [source] Randomized comparison of vasoseal and angioseal closure devices in patients undergoing coronary angiography and angioplastyCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2002Nicolas W. Shammas MD Abstract AngioSeal (AS) and VasoSeal (VS) are collagen-based arterial closure devices utilized to achieve earlier hemostasis and ambulation in diagnostic and interventional percutaneous procedures. To our knowledge, there has been no randomized studies comparing these two devices as approved for use in the United States. One hundred fifty-seven patients were randomized to receive either the 8 Fr AS (n = 79) or VS (n = 78) closure device. Data on 95 patients who had coronary angiography (49 AS, 46 VS) and 55 patients who underwent angioplasty (28 AS, 27 VS) were completed. Heparin was not administered during the coronary angiogram procedure. The activated clotting time was kept at approximately 300 sec during angioplasty. Patients on coumadin or GP IIb/IIIa platelet inhibitors were not included in this study. The time unit interval to achieve hemostasis in this study was based on the time the AS tension spring was left over the common femoral artery following collagen deployment as per the manufacturer's instructions (20 min). Time to hemostasis, time to ambulation, and major and minor complications were prospectively recorded. Two-tailed t -test and chi-square analysis were performed on continuous and dichotomous variables, respectively. For the angiogram-only subgroup, time (min) to hemostasis (20.51 ± 4.36 vs. 18.59 ± 11.77; P = 0.30) and ambulation (145.71 ± 124 vs. 109.89 ± 60.37; P = 0.075) were not statistically different for the AS and VS, respectively. Similarly, for the angioplasty subgroup, time (min) to hemostasis (24.23 ± 12.70 vs. 19.57 ± 2.27; P = 0.077) and ambulation (607.32 ± 344.22 vs. 486.48 ± 200.37; P = 0.12) were not statistically different for both AS and VS, respectively. Furthermore, there were no statistical differences in deployment failure, major, minor, or total complication rates between the two devices. In the absence of GP IIb/IIIa inhibitors, VS and the 8 Fr AS devices have statistically similar time to hemostasis and ambulation as well as device failures and complication rates following coronary angiography and angioplasty. Cathet Cardiovasc Intervent 2002;55:421,425. © 2002 Wiley-Liss, Inc. [source] | ||||||||||