Abstract: 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.