Inflation rate control circuit for blood pressure cuffs
US4969466A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1988 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Sep 15, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/0225
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.