ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The Veterans Administration has developed a program to evaluate the level of competency of its medical equipment repairmen and to recognize those who surpass an established level of competency. This evaluation is carried out by means of testing. A passing score of 70% on all sections of the exam results in certification while failure results in enrollment in correspondence or short courses. Periodic evaluations of the exam are carried out to determine questions to be added or deleted and those which should be reworded. Since time limits are set for completing the exam, those time limits are also evaluated.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Digital ECG systems are inherently non-linear, and usually cannot be properly tested using linear frequency or time domain testing. It is shown that the use of sinusoidal or triangular input signals to test plotted outputs may provide misleading results. Principal factors are the characteristics of pre-sampling and interpolation filters. In addition to validating sampling rate and bit precision, it is best to test system performance with real electrocardiographic input signals and verification of output waveform integrity. integrity.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

This paper describes the steps and key factors involved in preparing an Electrical Safety Program tailored to meet the needs and resources of a patient care facility. The effectiveness of the program depends upon how well the Safety Committee completes the tasks involved. The Electrical Safety Program in use at Boston University Medical Center is described.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

A computer-based automated system forcontinuous unattended monitoring of evoked potentials, EEG, transcranial impedance, and transthoracic impedanceas well as conventional parameters, was developed for use in the neurosurgical intensive care unit. A total of 50 patients has been studied. In the initial phases of the program, only evoked potentials were monitored. As the program evolved, additional variables were added. Transcranial impedance measurements have potential for detection of asymmetries and space-occupying lesions. Transthoracic impedance measurements provide a convenient means for monitoring respiration rate and tidal volume, and have value for detecting intrathoracic fluid accumulation. The technical feasibility of unattended monitoring of EEG and evoked potentials has been demonstrated. In patients who were disoriented, but conscious, evoked potentials were stable. In patients with unstable neurologic status, evoked potentials showed considerable variability with time. A peak-detection algorithm was developed for on-line EEG monitoring, and a statistical-tracking procedure was implemented for detecting significant changes in EEG parameters. In general, lower-percentage delta-activity and higher mean-frequency correlated with increased responsiveness. In some patients, changes in evoked potentials and EEG were observed prior to observable neurologic changes. The study suggests that the non-invasive techniques under study have potential for detection of adverse trends, and as such may provide adjuncts for neurosurgical intensive care monitoring.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

This paper describes the design, construction, and use of a device that provides a quick functional test of respiration rate meters that operate on the principle of impedance pneumography. The device is simple in construction and operation.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The objective of this study was to evaluate the clinical application of electrical-admittance plethysmography with venous occlusion to monitor the human-limb blood flow. An instrument using the electrical admittance tecnique for computing limb blood volume change was designed. The blood-flow rate at the onset of venous occlusion can be calculated from the initial slope of the volume change. Venous occlusion, acquisition of the admittance signal caused by the arterial inflow to the limb, its processing and display of blood volume change are carried out automatically. Less than 30 seconds are required for each cycle of this sequential procedure. This paper describes the principles and operation of this system, and five examples of its application in a healthy subject and patients.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

A microprocessor for pulmonary function testing is described. The system employs a KIM-1 microprocessor, with 2K read-only memory and 1K random-access memory, a Datel 12 bit A/D converter and power supply. The system is programmed on a linear basis, and displays standard pulmonary function values and ratios of ATPS BTPS.

ISSN:0363-8855    

出版商:OVID    

年代:1979

数据来源: OVID