Automatic digital blood pressure is a portable monitoring device for accurate measurements of human blood pressure. This latest state of the art device uses the oscillometric method of blood pressure measurement. This means the monitor detects your blood’s movement through your brachial artery and converts the movements into a digital reading. An oscillometric monitor does not need a stethoscope so the monitor is simple to use.
Oscillometric method uses a sphygmomanometer cuff with an electronic pressure sensor (transducer) to observe cuff pressure oscillations, electronics to automatically interpret them, and automatic inflation and deflation of the cuff. The pressure sensor is accurately calibrated to measure exact pressure readings. Oscillometric measurement requires less skill than the auscultatory technique and may be suitable for use by untrained staff and for automated patient home monitoring. The cuff is inflated to a pressure initially in excess of the systolic arterial pressure and then reduced to below diastolic pressure over a period of about 30 seconds. When blood flow is nil (cuff pressure exceeding systolic pressure) or unimpeded (cuff pressure below diastolic pressure), cuff pressure will be essentially constant. When blood flow is present, but restricted, the cuff pressure, which is monitored by the pressure sensor, will vary periodically in synchrony with the cyclic expansion and contraction of the brachial artery, i.e., it will oscillate.
Over the deflation period, the recorded pressure waveform forms a signal known as the cuff deflation curve. Special adaptive filters extract the oscillometric pulses from the cuff deflation curve. Over the deflation period, the extracted oscillometric pulses form a signal known as the oscillometric waveform (OMW). The amplitude of the oscillometric pulses increases to a maximum and then decreases with further deflation. Analysis algorithms are employed to estimate the systolic, diastolic arterial pressure and pulse rate.