BT17i
Blood Pressure User’s Guide
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5
6.
Lay down the arm of the test person on the table with an open hand.
Important:
The test person must remain still during data collection—no movement of
the arm or hand during measurements.
7.
Start your measurement.
8.
Quickly and repeatedly squeeze the bulb to inflate the cuff on the test person’s arm.
Continue inflating the cuff to a pressure between 150 and 170 mm Hg. When this
pressure is reached, set the bulb pump down onto the table. The built-in pressure
release valve will slowly deflate the cuff.
9.
After the measurement is finished, release the remaining air in the cuff by turning
the valve. You should be able to hear air coming out of the cuff.
Extra tips
Blood pressure readings will differ from person to person and even between
measurements on the same individual. Do not expect to receive the same
measurements each trial since there are many factors that cause a person’s blood
pressure to increase or decrease. Use the following tips to take accurate measurements:
•
The test person’s arm and hand must remain still during measurements; hand open
– no fist!
•
The arm should be at heart level and is best supported.
•
Proper placement of the pressure cuff will increase the accuracy of your blood
pressure measurements.
•
Remove any clothing that may cover or constrict the portion of the arm being
measured.
•
The blood pressure increases with the age. The rule of thumb for the normal systolic
pressure is the formula 100 + age.
•
Blood pressure values are rounded to 5 mmHg.
Determining the heart rate
The heart rate (beats per minute) can be calculated using the following formula:
ℎ
𝑒𝑎𝑟𝑡
𝑟𝑎𝑡𝑒
=
𝑛𝑢𝑚𝑏𝑒𝑟
𝑜𝑓
𝑚𝑎𝑥𝑖𝑚𝑎
−
1
𝑡𝑖𝑚𝑒
𝑜𝑓
𝑡
ℎ
𝑒
𝑙𝑎𝑠𝑡
𝑚𝑎𝑥𝑖𝑚𝑢𝑚
−
[
𝑡𝑖𝑚𝑒
𝑜𝑓
𝑡
ℎ
𝑒
𝑙𝑎𝑠𝑡
𝑚𝑎𝑥𝑖𝑚𝑢𝑚
]
∗
60
•
Count the number of local maxima in the descending part of the graph.
•
In addition, use the scan option to read out the time of the first and the last maxima.
•
Calculate the heart rate.
Determining the blood pressure
The result of the measurement with the Blood Pressure sensor is a pressure versus time
graph, in which the pressure pulses of the blood are superposed on the decaying trend
pressure of the cuff.
1. Determining the blood pressure manually from the graph
The simple method of determining the blood pressure is manually, directly from the
pressure graph. The point at which the largest pressure pulses are occurring
corresponds to the Mean Arterial Pressure (MAP). The point above the mean pressure
at which the pressure difference grows rapidly correlates to the systolic pressure. The
