BIOS Diagnostics BD240 - B Common Sources of Error; C Fitting the Wide Range Cuff

3.3B Common Sources of Error
All efforts by the patient to support the arm can increase the blood pressure. Make sure you are in a comfortable,
relaxed position and do not activate any of the muscles in the measurement arm during the measurement. Use a
cushion for support if necessary.
ATTENTION!
Comparable blood pressure measurements always require the same conditions with a peaceful and
calm environment. Ensure that you take measurements under the same conditions to obtain an accurate
estimate of blood pressure variation patterns.
• If the arm artery lies considerably lower or higher than the heart, an erroneous value of blood pressure is
measured. Each 15 cm difference in height results in a measurement error of 10 mmHg.
• A loose cuff causes false measurement values.
• With repeated measurements, blood accumulates in the arm, which can lead to false results. Consecutive blood
pressure measurements should be repeated after at least a 15 second pause or after the arm has been held up in
order to allow the accumulated blood to flow away.
3.3C Fitting the Wide Range Cuff
a) Put the end of the cuff (with fastener) through the metal ring, making
the cuff a cylinder. (Ignore this step if your cuff is already set up.) Proper
assembly allows the Velcro
®
to match up properly.
b) Place the cuff around your bare arm. Make sure the bottom edge of the
cuff is about 1” (2-3 cm) above the elbow joint. Adjust the cuff so that
the rubber tubing under the cuff lies over the brachial artery, which runs
on the inside of the arm (see Fig. b). The red material should be over the
brachial artery.
c) Pull the cuff and tighten it by attaching the Velcro
®
fastener. Measure on
your non-dominant arm, unless there is a >10 mmHg difference with the
other arm, in which case use the arm with the higher pressure.
d) The cuff should fit snugly around the arm, but not too tight. You should
be able to fit two fingers under the cuff. If the cuff is the wrong size,
the deivce will not measure your blood pressure accurately. Contact the
store, or BIOS Medical for other sized cuffs.
a)
d)
b)
c)