ISSN:0363-8855    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Power quality issues are becoming more important as more medical equipment utilizes microprocessor controls and switched DC power supplies. Externally and internally induced power surges and harmonics can have a dramatic effect on equipment performance. The effectiveness of a goodi “Equipment Management Program” can be greatly affected by poor power quality in today's hospitals. With many hospitals having been constructed in the 1970's, there is an increased likelihood that this issue will play a part in equipment downtime, and more importantly in “unable to duplicate” findings by the Clinical Engineering staff. Resolving power quality problems can have a dramatic impact on equipment performance, uptime, and cost of maintenance. This presentation will focus on identifying power quality problems, solutions, and an overall management scheme to minimize the impact on the performance of critical equipment that your facility and staff rely on to deliver cost effective patient care.

ISSN:0363-8855    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The Nellcor N-CAT N-500 is a non-invasive blood pressure monitor that has the potential to reduce the need for invasive arterial blood pressure measurements requiring an arterial cannula. Designed using the principles of tonometry, it is able to determine systolic, diastolic and mean arterial blood pressure continuously on a beat-to-beat basis. The purpose of this study was to compare systolic and diastolic pressures obtained by traditional means (onset and disappearance of Korotkoff sounds) with those obtained by the N-CAT monitor, so as to determine the accuracy and bias of the obtained measurements. Using 24 consecutive patients free of cardiovascular disease, left and right arm blood pressures were taken by both auscultation and the N-CAT monitor. The monitor was able to track systolic blood pressure fairly accurately as compared to the cuff pressure, with a bias of −0.71 mm Hg. However, the monitor tended to underestimate diastolic blood pressure by an average of −10.38 mm Hg, a fact of potential clinical concern.

ISSN:0363-8855    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The capability of Heat and Moisture Exchangers in “trapping”heat and moisture was experimentally evaluated by means of an original procedure. The proposed methodology is based on the current measurement of temperature and relative humidity in four unidirectional flow ways: botn sides of patient and servoventilator have two-way flow, two of which let the medical gases into the HME and two that let out the elaborated air. Starting from the relative humidity data measured by four miniaturized capacitance sensors, the uncertainty associated to the absolute humidity determination was also evaluated and compared to the off-balance recorded during measurements. Finally, the proposed methodology was verified by testing a couple of different HMEs and the effectiveness in assessing HME efficacy has clearly emerged.

ISSN:0363-8855    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

A glucose biosensor based on an amperometric oxygen electrode has been developed. Glucose biosensors with glucose diffusion membranes prepared from polycarbonate (PC) membranes with high temperature annealing and from polytetrafluoroethylene(PTFE) membranes with partial epoxy-patch covering combined with Q7–2213 Silastic* coating have been studied and compared with biosensors with standard PC membranes and PTFE membranes. The sensors utilizing high temperature annealing PC as glucose diffusion membrane demonstrate a linearity up to 360 mg/dl with sensitivity of 0. 48 nA/mg/dl and a response time of about two to three minutes at 37 $$C. The sensors using PTFE membrane with partially epoxy-patch cover and an additional Q7–2213 Silastic* coating as glucose diffusion membrane demonstrate a linearity up to 400 mg/dl glucose with sensitivity of 0.32 nA/mg/dl and a response time of about five to six minutes at 37 $$C. Studies of the sensors for continuous operational long-term stability, show practically constant sensitivity of the sensor over four months. During this period the sensor was refilled several times with fresh enzyme material.

ISSN:0363-8855    

出版商:OVID    

年代:1997

数据来源: OVID