BT-720 Operation manual
P/N:720-ENG-OPM-ENG-R03
Bistos Co., Ltd.
2020.10
21
6.3 Measurement limits
According to the patient's condition, the oscillometric method has some limitations. This
measurement is to look for the regular pulse waves generated by arterial pressure. If the patient's
condition makes this detection method difficult, the measured value becomes unreliable, and pressure
measurement time increases. The user should be aware that the following conditions may interfere
with measurement method, making the pressure measurement unreliable or extend the time. In this
case, the patient's condition does not allow measurement.
Patient movement
If the patient is talking, moving, shaking or cramping, the measurement will be unreliable or
even impossible, as these may interfere with the detection of arterial pressure pulse, and
extend the pressure measurement time.
Arrhythmia
If the patient shows arrhythmia which results in irregular heartbeat, the measurement will be
unreliable and even cannot be done, and the pressure measurement time will be extended.
Use of an artificial heart-lung machine
If a patient is connected to an artificial heart-lung machine, the measurement will be impossible.
Pressure changes
If the arterial pressure pulse is being analyzed to obtain a measured value at a certain time and
the blood pressure of the patient changes rapidly, the measurement will be unreliable or
impossible.
Severe shock
If the patient is in severe shock or hypothermia, the pressure measurement will not be reliable,
because the decrease of blood flow to the periphery would cause decrease in arterial pulsation.
Limit heart rate
If the heart rate is below 40bpm (beats / min) or above 240bpm (beats / min), the blood
pressure measurement is impossible.
Obese patients
A thick layer of fat around a limb blocks the arterial oscillation so that it cannot reach the cuff.
The accuracy is lower than normal.
Environmental Requirements
Measuring blood pressure should meet the environment range as follow:
ambient humidity 30%
～
85%, no condensing,
ambient temperature 5
～
40
℃
,
Atmospheric pressure: 700hPa
～
1060hPa.
NIBP performance and measurement accuracy will be affected beyond the range.
6.4 Measurement procedure
6.4.1 Prepare the measurement
1.
Turn on the monitor, and check if it works properly.
2.
Verify the patient category, and make changes if improper. Depending on the current patient
type, the patient type is selected in the patient information interface.
3.
Connect the blood pressure cuff extension tube to the monitor.
4.
Select the cuff in accordance with the following method, make sure that the cuff is completely
deflated, and then tie it to the upper arm or thigh of the patient.
Determine the limb circumference of the patient.
Select the appropriate cuff (marked with appropriate limb circumference). Cuff width
should be 40% of the limb circumference (50% for neonate) or 2/3 of the upper arm
length. The length of the inflated part of the cuff should be sufficient for 50%~80%
around the limb.
Place the cuff on the upper arm or thigh of the patient, and ensure that the marking
“ARTERIA” is located just above the appropriate artery. Make sure that the cuff does not
