S500 Handheld Pulse Oximeter
SINNOR Instruments, Inc.
Make sure to insert the finger to a suitable depth into the sensor so that the fingernail is just
opposite to the light emitted from the sensor.
To acquire accurate results, please read data until the sensor is steadily placed.
Readings may not be accurate when either the sensor or the patient is moving.
5.3 Measurement Limitations
If the accuracy of any measurement does not seem reasonable, first check the patient’s vital signs
by an alternate method. Then check the instrument for proper function.
Inaccurate measurements may be caused by:
Incorrect sensor application or use;
High-frequency electrical noise, such as noise from electrosurgical apparatus connected to the
system;
Significant levels of dysfunctional hemoglobins (e.g.,carboxyhemoglobin or methemoglobin);
Significant concentrations of dysfunctional hemoglobin, such as carboxyhemoglobin and
methemoglobin;
Intravascular dyes such as indocyanine green or methylene blue;
Exposure to excessive illumination, such as surgical lamps (especially ones with a xenon light
source), bilirubin lamps, fluorescent lights, infrared heating lamps, or direct sunlight (exposure to
excessive illumination can be corrected by covering the sensor with a dark material);
Excessive patient motion;
Venous pulsations;
SpO2 is too low;
Improper sensor installation or incorrect contact position of the patient;
Placement of a sensor on the same extremity with a blood pressure cuff, arterial catheter, or
intravascular line.
Polluted fingernail or fingernail polish or artificial fingernail.
Loss of pulse signal can occur in the following situation:
The sensor is too tight;
There is excessive illumination from light sources such as a surgical lamp, a bilirubin lamp, or
sunlight;
A blood pressure cuff is inflated on the same extremity as the one with a SpO2 sensor attached;
The patient has hypotension, severe vasoconstriction, severe anemia, or hypothermia;
There is arterial occlusion proximal to the sensor;
The patient is in cardiac arrest or in shock.
5.4 Precautions
NOTE
Do not perform SpO2 monitoring and NIBP measurements on the same arm simultaneously.
Obstruction of blood flow during NIBP measurements may adversely affect the reading of the
SpO2 value.
WARNING
Check if the sensor cable is in normal condition before monitoring. Do not use the SpO2 sensor
once the package or the sensor is found damaged.
Remove the SpO2 sensor from the patient after measurement.