AJP - Heart and Circulatory Physiology, Vol 244, Issue 3 413-H416, Copyright © 1983 by American Physiological Society
Automated limb blood flow plethysmograph
R. R. Marcus and S. M. Horvath
An automated limb blood flow plethysmograph has been developed and
interfaced to a PDP-11/60 computer. This system automatically inflates
blood pressure cuffs, calibrates strain gauges, provides real-time display
of limb circumference changes, and provides digital output of limb blood
flow and real-time graphic display of cuff pressure. The system has been
designed to require a minimum amount of user interaction by providing
automatic calibration in situ, which is initiated by depressing a switch,
and automatic venous cuff inflation, which initiates computer analysis of
blood flow data. Digital and graphic display of blood flow is provided on a
computer terminal 12 s after the start of venous occlusion. All raw data
are stored on a disk for optional postexperiment analysis, which enables
each blood flow curve to be graphically displayed and reanalyzed under user
control. Calculated data are stored on a disk for output to a line printer
at the conclusion of an experiment. A trend plot of all analyzed blood
flows can be displayed on a computer terminal anytime during an experiment.
