A device used to measure blood pressure, the sphygmomanometer has three significant features: an 'inflation bulb', 'inflatable cuff' and 'manometer'. The 'inflation bulb' is a hand pump that was used to pump air into the 'inflatable cuff'. This was placed around the patient's upper left arm, at roughly the same vertical height as the heart, while the subject was in an upright position. Once inflated, the cuff restricted blood flow. Listening with a stethoscope to the brachial artery at the elbow, the doctor then slowly released the pressure in the cuff. As the pressure fell, a pounding sound was heard when the bloodflow resumed in the artery. At this point, the 'manometer' (pressure meter) was used to record the systolic blood pressure. As the cuff pressure was further released the sound stopped and the doctor recorded the diastolic blood pressure. These figures were then analysed to see if the patient had high or low blood pressure.