Non Invasive Blood Pressure Monitor
Automatic Blood Pressure Monitor
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.