Journal article
Automatic quantitation of venous hemodynamics with an electrically calibrated strain gauge plethysmograph
Medical instrumentation, Vol.11(4), pp.240-243
07/1977
PMID: 895598
Abstract
Strain gauge plethysmography has permitted noninvasive quantitation of altered venous hemodynamics in the legs of patients with venous disease. A new plethysmograph has been developed which avoids previous problems of mechanical calibration of gauges and the necessity for a recorder for calculating blood flows. This instrument permits accurate electrical calibration of mercury-in-Silastic gauges which are effectively at the corners of the Wheatstone bridge and are supplied by constant current for linear output. A timer and follow-and-hold circuit allow automatic calculation of rates of change in limb circumference and, thus, blood flow, from a panel meter. The accuracy of the automatic versus the graphic methods of quantitating venous outflow and reflux flow was determined in 20 normal subjects. Venous outflows were 15.1 +/- 0.5 (mean +/- 1 S.E.M.) and 15.9 +/- 0.4 cc/min/100 cc by automatic and graphic methods, respectively (r = 0.96, p less than 0.01). Reflux flows were 2.1 +/- 0.2 and 2.3 +/- 0.2 cc/min/100 cc by the automatic and graphic methods, respectively (r = 0.93, p less than 0.01). This plethysmograph may prove to be a simple, rapid, and accurate device for evaluating altered hemodynamics in venous disease.
Details
- Title: Subtitle
- Automatic quantitation of venous hemodynamics with an electrically calibrated strain gauge plethysmograph
- Creators
- T A ThomsenE HokansonR W Barnes
- Resource Type
- Journal article
- Publication Details
- Medical instrumentation, Vol.11(4), pp.240-243
- Publisher
- United States
- PMID
- 895598
- ISSN
- 0090-6689
- Language
- English
- Date published
- 07/1977
- Academic Unit
- Orthopedics and Rehabilitation; General Internal Medicine; Internal Medicine
- Record Identifier
- 9984024544002771
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