reduce naturally occurring blood pressure variability during the test. For proper
comparisons, the subject should be seated comfortably with feet flat on the floor,
and have rested for 5 minutes before the first reading to allow blood pressure
levels to stabilize. The patients back, elbow and forearm should be supported,
and the middle of the cuff should be at the level of the right atrium. There
should be no talking or moving during the measurement and if comparing to an
aneroid gauge or mercury column, observers should avoid parallax and be careful
not to round measurements.
The most accurate way to compare devices is to take two readings at the same
time. However most people and doctor’s offices do not have the equipment
necessary to measure blood pressure from two devices simultaneously. To
take sequential measurements properly requires a pair of initial measurements
to determine the subjects blood pressure level: first with the reference
equipment, followed by 60 seconds, then with the monitor-under-test. The
actual accuracy test requires three pairs of measurements with 60 seconds
between measurements. These measurements are averaged and a comparison
can be made. Since most people tend to relax and their blood pressure falls
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