Mindray DPM 1, Operator'S Manual

Page: 21 / 54

4-1
4
Measurement
4.1 Measuring Principle
SpO
2
monitoring is a non-invasive technique used to measure the amount of oxygenated
haemoglobin and pulse rate by measuring the absorption of selected wavelengths of light.
The light generated in the probe passes through the tissue and is converted into electrical
signals by the photodetector in the probe. The DPM1 processes the electrical signal and
displays on the screen digital values for SpO
2
and pulse rate. The displayed SpO
2
value is of
functional saturation.
The sensor measurement wavelengths are nominally 660nm for the red LED and 940nm for
infrared LED. The maximum optical power output for LED is 4mW.
4.2 Precautions
NOTE
z
Do not perform SpO
2
monitoring and NIBP measurements on the same arm
simultaneously. Obstruction of blood flow during NIBP measurements may
adversely affect the reading of the SpO
2
value.
z
A measurement shall last longer than 15 seconds. Otherwise, new data of next
measurement can’t be added to the same patient.
z
DPM1 is not recommended for prolonged monitoring.
WARNING
z
Check if the sensor cable is in normal condition before monitoring. Do not use the
SpO
2
sensor once the package or the sensor is found damaged.
z
Don’t use DPM1 to measure patients whose pulse rate is lower than 25bpm, which
may cause incorrect results.
z
Remove the SpO
2
sensor from the patient after measurement.
z
As with any medical equipment, carefully route patient cabling to reduce the
possibility of patient entanglement or strangulation. Cables of electrical surgical
equipment should not be winded around that of the SpO
2
sensor.
z
Do not put the sensor on extremities with arterial catheter or venous syringe.