Non-Invasive Pressure Measurement Principles - Omron HBP-1100 Manual De Instrucciones

Non-Invasive Pressure Measurement Principles
Oscillometric method
The beat in the pulsation generated by the contraction of the heart is captured
as the pressure inside the cuff to measure the blood pressure. If the cuff
wrapped around the upper arm is pressurized sufficiently, the blood flow
stops, but the beat of the pulsation is present and the pressure inside the cuff
receives this and oscillates. Next, as the pressure inside the cuff gradually
decreases, the oscillation of the pressure within the cuff gradually increases
and reaches a peak. As the pressure within the cuff decreases further, the
oscillation decreases from its peak.
The pressure within the cuff and the relationship with the increase and
decrease of the oscillation within the cuff in this series of processes are
stored into memory, calculations are carried out, and the blood pressure
value is determined.
The pressure within the cuff when the oscillation increases drastically is
the systolic pressure and the pressure within the cuff when the oscillation
decreases drastically is the diastolic pressure. Also, the pressure within the cuff
when the oscillation peaks is taken as the average pulsation pressure.
The oscillometric method does not determine the blood pressure value
instantly like a microphone type automatic blood pressure gauge with the
auscultation method, but rather determines it from the series of change
curves as explained above. Therefore, it is not easily affected by external
noise, an electric scalpel or other electro surgical instruments.
KOROTKOV SOUNDS
RADIAL PULSE
5 SEC
L.A. Geddes,
"The Direct and Indirect Measurement of Blood Pressure", Year Book Medical Publishers, Inc. 1970
22
CUFF
PRESSURE
OSCILLATIONS IN CUFF PRESSURE
Comparison between the auscultatory, oscillometric and
palpatory methods of measuring blood pressure.