Blood pressure measuring device having adaptive cuff deflation rate

Abstract

A device is disclosed for making blood pressure measurements using an inflatable cuff (12), wherein the cuff deflation rate is established based upon prior blood pressure measurements. The cuff is adapted for applying pressure to a patient adjacent a blood vessel. the device includes means (14, 16) for inflating and deflating the cuff, a sensor system (60) for providing sensor signals during cuff deflation that correspond to the cuff pressure and to the blood flow surges in the blood vessel, and a process controller (100). The process controller causes inflation of the cuff to a first pressure and subsequent deflation of the cuff from the first pressure to a lower second pressure at a preestablished deflation rate, the inflation and subsequent deflation of the cuff comprising one measurement cycle. The process controller also processes the sensor signals provided during a given measurement cycle in order to determine at least one blood pressure value indicative of the patient's blood pressure for that measurement cycle. The process controller includes parameter setting means for establishing the cuff deflation rate for a given measurement cycle based upon the blood pressure value determined during at least one previous measurement cycle. The parameter setting means may establish the deflation rate based upon both blood pressure and pulse rate values determined during previous measurement cycles. The deflation rate may be established so as to provide a predetermined number of blood flow surges between systolic and diastolic pressures in the given measurement cycle.