Heartbeat detection is a simple oscillometric method used to determine systolic blood pressure (SBP) and diastolic blood pressure (DBP). The simplified measurement is based on the idea that the amplitude of the heartbeat signal changes as the cuff is inflated over the SBP. While the cuff is deflated, the amplitude of the heartbeat signal grows as the cuff pressure passes the systolic pressure of the patient. As the cuff pressure is further reduced, the pulsations increase in amplitude until the pulsations reach a maximum pulse known as the mean arterial pressure (MAP),and then reduce rapidly until the diastolic pressure is reached (Figure 1-2d).