Kenneth S Stack

US Patent:

40033708, Jan 18, 1977

Filed:

Oct 14, 1975

Appl. No.:

5/622209

Inventors:

Tuncay Emil - Fountain Valley CA
Kenneth Elmer Stack - Laguna Hills CA

Assignee:

American Hospital Supply Corporation - Evanston IL

International Classification:

A61B 502

US Classification:

128 205D

Abstract:

A compact, portable, self-contained unit includes a resistive strain gauge transducer for sensing blood pressure from an indwelling catheter to generate a signal representative of instantaneous pressure. This pressure signal is coupled to the signal inputs of a bank of comparator circuits having their outputs connected to associated ones of a string of light-emitting diodes (LEDs) connected in series across a source. The other inputs of the comparators are connected to associated nodes of a progressive reference voltage divider network. At any given time, all comparators having their signal inputs at a higher potential than their associated reference voltages will have their outputs "LOW," and those comparators having their signal inputs at a lower potential than their associated reference voltages will have their outputs "HIGH. " Hence, a single LED is energized at any given time, and it represents the instantaneous pressure value. The value is easily read from a scale alongside the LEDs which are arranged in a line.