Mindray VS 8A, Operator'S Manual

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11
Measuring Noninvasive Blood Pressure
(NIBP)
11.1 NIBP Introduction
The monitor uses the oscillometric method for measuring the non-invasive blood
pressure (NIBP). NIBP measurement is based on the principle that pulsatile blood flow
through an artery creates oscillations of the arterial wall. The oscillometric device uses a
blood pressure cuff to sense these oscillations that appear as tiny pulsations in cuff
pressure.
Two algorithms can be used on the monitor:
■
Inflation: at the inflation stage, the device effects a slow inflation of a cuff while
simultaneously detects oscillations. As soon as systolic pressure is determined, the
cuff is deflated. The oscillations appeared during inflation increase in amplitude to
a peak amplitude (which approximates to the mean pressure) with increasing cuff
pressure and then decrease in amplitude. If the measurement fails at the inflation
stage, the device will automatically continue the measurement at deflation stage.
■ Deflation: the device measures the amplitude of pressure changes in the
occluding cuff as the cuff deflates from above systolic pressure. The amplitude
suddenly increases as the pulse breaks through the occlusion in the artery. As the
cuff pressure decreases further, the pulsations increase in amplitude, reach a
maximum (which approximates to the mean pressure), and then diminish.
The oscillometric method measures the mean pressure and determines the systolic and
diastolic pressures.
NIBP measurement adopting inflation algorithm is intended for adult and pediatric
patients, and NIBP measurement adopting deflation algorithm is intended for adult,
pediatric, and neonatal patients.
NOTE
•
Blood pressure measurements determined with this device are equivalent to
those obtained by a trained observer using the cuff/stethoscope
auscultatory method or an intra-arterial blood pressure measurement
device, within the limits prescribed by the American National Standard:
manual, electronic, or automated sphygmomanometers.
•
NIBP measurement can be performed during electro-surgery and discharge
of defibrillator.