a noninvasive blood pressure measuring and recording system includes an inflatable cuff for encircling a portion of the human body , a pump for inflating and deflating the cuff for selectively occluding an arterial vessel , a detector for detecting flow variation through the arterial vessel as cuff pressure is decreased , and a recorder for recording cuff pressure values corresponding to the detected flow variation . the pump is a reversible single stroke sleeve diaphragm pump pneumatically coupled to the cuff and provides a selected , repeatable linear rate of pressure change for accurate , repeatable measurements through an automatically controllable motor operating at a selected constant speed to actuate the pump . a speed control changes the linear rate of pressure change in response to detected flow variations to enhance accuracy of measurement of selected variations , such as those identified with the systolic and diastolic pressures . a variable volume ballast tank may be pneumatically coupled to the cuff and pump to accommodate different cuff sizes . pressure and flow variation signals may be utilized to simply and easily provide one or more different representations or measurements of detected flow variations , including additional aural representation concurrent with the measurement process for aural diagnosis .