ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

This paper constitutes an overview of FDA's functions and activities, offering a brief introduction to the Medical Device Amendments, and performance standard requirements from FDA's point of view. It discuss the agency's voluntary standards policy and the required conditions for deferral of mandatory standards. This paper also describes the Medical Device Standards Survey, and the role of the clinical engineer in standards development. It lists new Problem Definition Studies of the Bureau of Medical Devices which represent the first step in the new standards-development process.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Skin temperature-rise studies were conducted on both dry and gelled copper and aluminum-foil disposable dispersive electrodes applied to the anterior surface of the thighs of six female human subjects. Current levels and durations typical of maximum values used in surgical procedures were employed. It was found that the dry electrodes produced a higher skin temperature rise than electrolyte-coated electrodes. Dry electrodes were also found to be less predictable than the same electrode type coated with low-resistivity electrode paste. A coefficient of performance has been developed for comparing the thermal performance of the electrodes. (However, the results herein should not be extrapolated to the newer dry insulated (capacitive) electrodes which have not yet been thermally evaluated.)

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Accidental burns or burn-like injuries continue to occur during lengthy surgical procedures. Many remain unexplained as to the cause. The threat of litigation suppresses discussion of the incidence of injuries of this type — which are not uncommon. The same threat appears to have suppressed wider discussion of potential solutions. Many of these burn-like injuries are not burns but pressure sores, and as such are preventable. Strategies for reducing the numbers of injuries of this type are discussed.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The evoked potential has been referenced in various forms for several thousand years. This paper includes a brief review of the early accounts of bioelectricity, beginning with the electric fish, continuing through the first energy sources and various neurophysiologic studies. Early accounts of evoked potential instrumentation, the evolution of special-purpose evoked potential equipment, and recent laboratory systems are all discussed.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The clinical utility of evoked potential measurement and analysis has come to the fore-front of neurological investigations with the recent advances in instrumentation technology. Evoked potential measurements have shown changes secondary to traumatic head injury, cerebral vascular disorders, neuromuscular dysfunctions, nerve conduction anomalies, and a variety of other pathologies. With this widespread acceptance across the nation, the clinical engineering community is more frequently being asked to participate in the establishment of instrumentation laboratories for these investigations. The present article gives a brief historical and theoretical introduction to these techniques, as well as a discussion of the instrumentation, recording electrodes, electrode placement, stimulation parameters and diagnostic considerations. It is hoped that this article will generate interest among the readership and promote the level of expertise in electrodiagnostic evaluations within the clinical engineering community.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

An image-processing scheme which produces an environmentally familiar basis for enhancing two-dimensional displays of diagnostic information has been developed. The transformation yields true projections of apseudo-solid, formed by coding gray levels as displacements in the third dimension. The projections conform to rules consistent with monocular cues to depth perception. These rules apply when an opaque object is viewed from one direction and illuminated from another. The pseudo-solid transformation has been applied to dental radiographs, nuclear-medicine scans, and data produced by computerized axial tomography in order to survey its potential utility in a variety of clinical applications. Preliminary findings suggest that applying the method to biomedical images extends the perceptual capabilities of the diagnostician.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

A Tektronix 4956 graphics tablet with a Tektronix 4051 graphics computer was used to digitize hard copy recordings obtained in a study of the effects of antihypertensive drugs on blood velocity. Hard Copy spectral displays (sonagraphs) of Doppler audio blood velocity signals were digitized, givingpeak height (peak velocity), mean height (mean velocity), slope (acceleration) and area (stroke volume index). Coefficients of variation, even for inexperienced operators were 1–5%, except for slope (11%). For systolic time intervals, data was entered by touching a magnetic pencil to time landmarks on a recording of ECG, carotid pulse and phonocardiogram. Mean and standard deviation of PEP/LVET and 1/PEP2 were printed out after entering 10 successive cardiac cycles. Co-efficients of variation for inexperienced operators were 2–3%, much less than for fully manual methods, time involved was 1/10 that required for manual measurement and calculation of Systolic Time Intervais (STIs). The methods presented permit inexpensive, convenient access to computer processing of cardiovascular signals.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

This paper describes an ECG/Respiration monitor calibrator used by the Biomedical Staff to check such units quickly, inexpensively and accurately. The calibrator can be constructed by the Biomedical Engineering Staff in one day for a parts cost of less than fifty dollars. Once the calibrator is connected to the patient cable of an ECG/ Respiration monitor, the calibrator will generate concurrently a calibrated rate and amplitude ECG-pulse and respiration waveform.

ISSN:0363-8855    

出版商:OVID    

年代:1980

数据来源: OVID