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ENGLISH
room etc.), oxygen bar, the community medical center, alpine area and it also can
be used before or after sports, and the like.
This device is not appropriate to be used for continuous monitoring.
2.3
Principle of Measurement
The measurement of pulse oximeter is that it uses a multi-functional
oxyhemoglobinometer to transmit some narrow spectrum light bands through
blood samples and to measure attenuation of spectrum with different wavelengths
according wo the characteristic that RHb, O
2
HB, Met Hb and COHb absorb the
light of different wavelength, thereby determining O
2
Hb saturation of different
fractions. O
2
Hb saturation is called “fractional” O
2
Hb saturation.
Fractional O
2
Hb saturation = [O
2
Hb / (RHb + O
2
Hb + Met Hb + COHb)] × 100
Oppositely, pulse oxygen oximeter measures functional O
2
Hb saturation:
Functional O
2
Hb saturation = [O
2
Hb / (RHb + O
2
Hb)] × 100
Present SpO
2
oximeter transmits light of two wavelengths only, red light
(wavelength 660 nm) and infrared (wavelength 940 nm), to differentiate HbO
2
from
HbR. One side of the sensor contains two LEDs, and the other side contains a
photoelectric detector. SpO
2
oximeter measures HbO
2
saturation in the blood by
the light plethysmograph when the pulse beats. The result is quite precise when
HbO
2
saturation is over 70% ~ 95%.
2.4 Caution
A. The finger should be placed properly (see the attached illustration of this
manual), or else it may cause inaccurate measurement.
B. The SpO
2
sensor and photoelectric receiving tube should be arranged in a way
with the subject’s arteriole in a position there between.
C. The SpO
2
sensor should not be used at a location or limb tied with arterial canal
or blood pressure cuff or receiving intravenous injection.
D. Do not fix the SpO
2
sensor with adhesive or else it may result in venous pulsation
and inaccurate measure of SpO
2
.
E. Make sure the optical path is free from any optical obstacles like rubberized
fabric.
F. Excessive ambient light may affect the measuring result. It includes fluorescent
lamp, dual ruby light, infrared heater, direct sunlight and etc.
G. Strenuous action of the subject or extreme electrosurgical interference may
also affect the accuracy.
H. Testee can not use enamel or other makeup on the finger.
