The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 13, 1990
Filed:
Sep. 15, 1988
James R Brooks, Portland, OR (US);
Spacelabs, Inc., Redmond, WA (US);
Abstract
A blood pressure monitor having a motor driven air pump for inflating an blood pressure cuff, and a control system for controlling the voltage applied to the motor to regulate the rate at which the cuff is inflated. The control system utilizes a microprocessor to calculate a desired inflation rate and then compare the desired inflation rate with the actual inflation rate to generate a control signal in the form of a pulse-width modulated square wave. The square wave is low-pass filtered to generate a voltage reference that is applied to one input of a comparator. The other input of the comparator receives a feedback signal indicative of the voltage applied to the motor. The comparator generates a sqaure wave having a duty cycle that is a determined by the polarity of the comparison at its inputs. The square wave modulates a semi-conductor switch which, in turn, controls the voltage applied to the motor.