PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Device Approval”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2004

Combined multichannel intraluminal impedance and manometry clarifies esophageal function abnormalities: study in 350 patients.

BACKGROUND: Combined multichannel intraluminal impedance and esophageal manometry (MII-EM) is a technique that uses an FDA-approved device allowing simultaneous evaluation of bolus transit (MII) in relation to pressure changes (EM). METHODS: During a 9-month period, beginning from July 2002 through March 2003, we prospectively performed combined MII-EM on all patients referred for esophageal function testing. Each patient received 10 liquid and 10 viscous swallows. Manometric findings were reported based on criteria described by Spechler and Castell for liquid swallows. MII findings were reported as having normal bolus transit if >/=80% (8/10) of liquid and >/=70% (7/10) of viscous swallows had complete bolus transit. RESULTS: Three-hundred fifty studies were evaluated from patients with a variety of symptoms having the following manometric diagnoses: normal manometry (125), achalasia (24), scleroderma (4), ineffective esophageal motility (IEM) (71), distal esophageal spasm (DES) (33), nutcracker esophagus (30), hypertensive lower esophageal sphincter (LES) (25), hypotensive LES (5), and poorly relaxing LES (33). None of the patients with achalasia and scleroderma had normal bolus transit. Fifty-one percent of patients with IEM and 55% of patients with DES had normal bolus transit while almost all (more than 95%) patients with normal esophageal manometry, nutcracker esophagus, poorly relaxing LES, hypertensive LES, and hypotensive LES had normal bolus transit. Dysphagia occurred most often in patients with incomplete bolus transit on MII testing. CONCLUSION: Esophageal body pressures primarily determine bolus transit with isolated LES abnormalities appearing to have little effect on esophageal function. MII clarifies functional abnormalities in patients with abnormal manometric studies.

Adolescent↗
PubMed1999

Long-term treatment with vagus nerve stimulation in patients with refractory epilepsy. The Vagus Nerve Stimulation Study Group E01-E05.

OBJECTIVE: To perform an open-label, long-term efficacy and safety/tolerability study of vagus nerve stimulation (VNS) of 454 patients with refractory epilepsy. METHODS: Subjects were enrolled from five clinical trials of VNS between 1988 and 1995 after undergoing an implantation of a pulse generator in the chest and a left cervical vagus nerve-stimulating lead coil. Patients were assessed at 6-month intervals until device approval. Seizure frequencies, medication treatment, and adverse events (AEs) were recorded and entered into a database. RESULTS: A total of 454 patients were implanted, and 440 patients yielded assessable data. A > or =50% seizure reduction postimplantation occurred in 36.8% of patients at 1 year, in 43.2% at 2 years, and in 42.7% at 3 years. Median seizure reductions compared with baseline were 35% at 1 year, 44.3% at 2 years, and 44.1% at 3 years. Most common AEs postimplantation at 1 year were hoarseness (28%) and paraesthesias (12%), at 2 years were hoarseness (19.8%) and headache (4.5%), and at 3 years was shortness of breath (3.2%). Continuation rates were 96.7% at 1 year, 84.7% at 2 years, and 72.1% at 3 years. CONCLUSION: Long-term, open-label vagus nerve stimulation (VNS) provided seizure reduction similar to or greater than acute studies, for median reductions and for those reaching a > or =50% seizure reduction. VNS remained safe and well tolerated, with nearly three-quarters of the patients choosing to continue therapy.

Adult↗
PubMed1993

Performance characteristics of Ultratherm fluid warmer.

Ultratherm Infusion Fluid Warmer Model 3703-1 (Ultratherm) is a disposable device approved by the Food and Drug Administration to warm fluids including blood and nutritional fluids. It has no temperature monitor or audible alarm and uses air-activated chemical heating elements in direct contact with loops of intravenous (i.v.) tubing. We studied the warming of blood and saline by Ultratherm using intratubing thermocouple wire probes. Internal warmer chamber temperature reached 58 degrees C within 40 min of activation, and a plateau of approximately 65 degrees C reached in 1 h was sustained over the next 5 h. Free hemoglobin measurements on 47 degrees C and 53 degrees C blood samples obtained as blood exited the warmer at 30 mL/h demonstrated 0.6% and 7% hemolysis, respectively. Room temperature blood at 500 mL/h and refrigerated blood at 100 mL/h were warmed to approximately 36 degrees C. Refrigerated blood at 500 mL/h was not warmed above 19 degrees C. At flow rates of 500, 100, and 30 mL/h, room temperature saline reached 34 degrees C, 45 degrees C, and 52 degrees C, respectively. The unmonitored, high, internal warmer chamber temperatures preclude the use of Ultratherm with blood or any fluids potentially damaged by excessive heat, and its use should be limited strictly to clear fluids. The utility of the warmer, even with clear fluids, is further limited to room temperature fluids, to a time interval between 1 and 6 h following activation, and to flow rates between 100 and 500 mL/h.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood↗
PubMed2001

Validation study of an automated wrist monitor, omron model HEM-608, compared with the standard methods for blood pressure measurement.

OBJECTIVE - The aim of our study was to assess the profile of a wrist monitor, the Omron Model HEM-608, compared with the indirect method for blood pressure measurement. METHODS - Our study population consisted of 100 subjects, 29 being normotensive and 71 being hypertensive. Participants had their blood pressure checked 8 times with alternate techniques, 4 by the indirect method and 4 with the Omron wrist monitor. The validation criteria used to test this device were based on the internationally recognized protocols. RESULTS - Our data showed that the Omron HEM-608 reached a classification B for systolic and A for diastolic blood pressure, according to the one protocol. The mean differences between blood pressure values obtained with each of the methods were -2.3 +7.9mmHg for systolic and 0.97+5.5mmHg for diastolic blood pressure. Therefore, we considered this type of device approved according to the criteria selected. CONCLUSION - Our study leads us to conclude that this wrist monitor is not only easy to use, but also produces results very similar to those obtained by the standard indirect method.

Adolescent↗
PubMed2005

Radiofrequency ablation of thoracic lesions: part 1, experiments in the normal porcine thorax.

OBJECTIVE: Radiofrequency ablation has been used extensively in the liver for the localized thermal coagulation of tumors. It has been applied more recently percutaneously in the lung under CT imaging guidance. In advance of our own clinical application, we performed experimental percutaneous radiofrequency ablation in normal lung tissues in a large animal model using a U.S. Food and Drug Administration-approved device to assess its use. MATERIALS AND METHODS: Radiofrequency ablation of 22 thoracic sites was performed in vivo in three pigs with an array-style electrode. Tissue impedance and ablation duration were measured for each site. The intact lungs were excised for gross inspection and for imaging with CT and MRI. Representative lesions were evaluated histologically. RESULTS: The mean intraprocedural tissue impedance was 93 Ohms (range, 52-184 Ohms). Six of 22 ablations exhibited a marked increase in impedance after 5 min of treatment. On gross inspection, parenchymal lesions were generally round and targetlike in appearance. CT showed sites of ablation to be composed of a heterogeneous inner zone surrounded by a high-density outer zone. On MRI, the inner zone was typically hyperintense on T1-weighted fast spin-echo imaging, and the outer zone was hyperintense on T2-weighted fast spin-echo imaging. At histology, the inner zone was characterized by coagulation necrosis, and the outer zone by hyperemia and edema. No acute lung-specific complications were seen. There was one extensive skin burn and one cardiac-related death. CONCLUSION: These results support current seminal clinical evidence that percutaneous radiofrequency ablation in the lung is feasible and can be applied safely. Radiofrequency-induced lesions in the normal porcine lung can be visualized with both CT and MRI; image appearance is concordant with histologic tissue changes.

Animals↗
PubMed2004

Measurement of end points in heart failure trials: jousting at windmills?

Advances in the treatment of congestive heart failure, a condition of increasing incidence and prevalence, have been made possible by knowledge gained from randomized clinical trials. The selection of end points in these trials has become a pivotal step in the drug and device approval process. In part because of the success of earlier trials, the number of study subjects required in order to realize an important improvement in survival has increased. This has led to the development of alternative combined and composite end points, often including surrogates for mortality. The limitations of these end points, the specific challenges associated with studies of patients with decompensated and diastolic heart failure, and other issues encountered during and after completion of heart failure trials, are discussed.

Biomedical Research↗
PubMed2006

Intragastric balloons: a temporary treatment for obesity.

(1) Intragastric balloons are a temporary non-surgical obesity treatment that induces short-term weight loss by partially filling the stomach to achieve satiety and reduce food intake. (2) Moderate weight loss may be achieved if patients adhere to a weight-reduction program. Weight gain often recurs when the balloon is removed after six months. (3) Abdominal pain, nausea, and vomiting are common, particularly in the first week after balloon implantation. (4) More data on benefits, harm, and cost effectiveness are required before the intragastric balloon can be compared with other short-term weight loss interventions, including low-calorie diets.

Bariatrics↗
PubMed2006

Advances in pediatric gastroenterology: introducing video camera capsule endoscopy.

The video camera capsule endoscope is a gastrointestinal endoscope approved by the U.S. Food and Drug Administration in 2001 for use in diagnosing gastrointestinal disorders in adults. In 2003, the agency approved the device for use in children ages 10 and older, and the endoscope is currently in use at Arkansas Children's Hospital. A capsule camera, lens, battery, transmitter and antenna together record images of the small intestine as the endoscope makes its way through the bowel. The instrument is used with minimal risk to the patient while offering a high degree of accuracy in diagnosing small intestine disorders.

Capsules↗
PubMed1994

Sample size requirements for evaluating heart valves with constant risk events.

A method is described for computing sample size requirements for a clinical study of a new heart valve, according to the guidance document recently revised by the FDA. The FDA requirements specify a one-sample hypothesis test in which the complication rates for the study valve are compared to fixed values determined from previous experience with approved devices. These values, which can differ for different complications and for mechanical or tissue valve types, are called OPC's (Objective Performance Criteria). The method described, using the Poisson distribution, provides a simple formula for computing the valve-years required corresponding to any OPC. At the OPC level required by the FDA guidelines (1.2%/year), the minimum follow-up necessary is about 800 valve-years.

Guidelines as Topic↗
PubMed1983

[Elaboration of a course in training galleries for use in testing of self rescue devices].

The approval of self rescuer devices for use in the underground needs, among other things, human testing in training galleries. As the training galleries are not the same in the different central rescue stations, the C.C.R. was entrusted with the task of developing a standard test for Belgium. After comparing data with two other countries of the E.E.C. and having devised two experimental courses, the C.C.R. launched a project for "Community Ergonomics Action" with the financial support of the Commission of the European Communities. This financial support enabled the C.C.R. to purchase equipment for the continuous measurement of various physiological parameters. This equipment was used to determine as accurately as possible the effort involved in passing through a specific type of roadway at a given speed. The resulting information helped device a third test course which entails an average oxygen uptake of approximately 1,2 l/min; the paper gives a detailed description of this test.

Belgium↗
PubMed2003

Stent grafts for the treatment of abdominal aortic aneurysms.

Stent grafting for treatment of abdominal aortic aneurysms (AAAs) has been a major advance in endovascular surgery. Initial success with the original endoluminal stent graft encouraged worldwide study of the technology. In the United States, the Food and Drug Administration (FDA) insisted on considerable experience with the devices before approval because of early problems with device rupture, stent fracture, fabric perforation, graft migration, and modular separation. Complications associated with the endovascular graft technology led many to recommend its use only in patients who were considered at "high risk" for the standard, open procedure. Further study and device improvements have led to results that indicate the procedure has the potential to reduce operating time and blood loss and shorten intensive care unit and hospital stays compared with open surgical intervention. At present, there are three FDA-approved devices available for use, and a fourth is expected in 2003. The ultimate decision by the individual practitioner or the institutional team regarding which patients should be treated with endovascular technology is still not entirely straightforward. Patient selection should be based on vascular anatomy, the availability of a suitable device, the patient's desire for a minimally invasive procedure, and a commitment to what is likely to be a lifetime of device surveillance.

Age Factors↗
PubMed1992

Medical devices; procedures for premarket notification, premarket approval, classification, performance standards establishment, banning devices, and availability of regulatory hearings--FDA. Final rule.

The Food and Drug Administration (FDA) is amending the medical device regulations governing procedures for premarket notification, premarket approval, classification, performance standards development, banning devices, and availability of regulatory hearings to conform these procedures to applicable provisions of the Safe Medical Devices Act of 1990 (the SMDA). Its publication promotes clarity and certainty to regulated industry and thus fosters economic growth by correcting the provisions in FDA's existing regulations to conform them to the now-governing statutory provisions.

Consumer Product Safety↗