Fingertip Pulse Oximeter Sensor was developed for high accuracy and simple usage for both doctors and non-medical use. Equipped with heart rate pulse & SpO2 measurement, this product is useful for monitoring the oxygen concentration in blood and the health of patients during respiratory diseases. Patient Movement can cause inaccurate reading as the probe easily dislodges. With this,if the patient is shivering or fussy, you may hold the hand steady or wait until the shaking has dispersed before resuming the test.The finger should be placed properly, or else it may give inaccurate readings. Excessive ambient light may affect the measuring result. Although the device has a soft rubber that shields it from light, it may not be able to avoid bright light shining directly on the device.