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Pulse Oximeter – General user (Non-technical) buying guide for pulse oximeter in view of current pandemic.

Pulse Oximeter

About Pulse Oximeter:

Pulse oximeter is a non-invasive small medical device used to measure oxygen saturation level [SpO2 (Peripheral haemoglobin oxygen saturation)] in blood with pulse rate, generally by using the fingertip or earlobe of the patient.

Pulse oximeter is generally used to get a quick reading of oxygen blood saturation level and pulse rate in emergency rooms or hospitals. People might use it during exercise, hiking, trekking, mountaineering etc to measure their blood oxygen level. Other users are with medical conditions, where doctors might suggest using pulse oximeters to keep a quick track of their blood oxygen level.

Working of Pulse Oximeter:

Pulse oximeter consists of a sensor to measure the oxygen saturation and a display for reading the values from this device. Sensors consist of two parts i.e. one work as transmitter of light (Light emitting diodes) and other works as receiver (Light Detector) on the other end (Fingertip/earlobe is placed in between these two parts). This device reads oxygen saturation level (SpO2) from the arterial blood (simultaneously reading pulse rate). Generally, it uses two lights for measuring SpO2 level i.e. red light and infra-red light, where absorbance for oxygenated haemoglobin and Deoxygenated haemoglobin varies for these two lights. Also, it cannot differentiate between Carboxyhaemoglobin from the normal haemoglobin.

Reference reading:

SpO2 in arterial blood greater than or equal to 95% is considered a Normal Condition whereas, if SpO2 in arterial blood is less than 90-95%, you may need to consult your doctor immediately and follow the instructions provided by him/her.


For this device to take reading correctly, a person should keep their hand stable without any movement. Due to movement you may get false reading. High pigmentation may also lead to false reading (pigmentation factor is stable during a reasonable period of time, so it may be correlated for correction in reading).

Various parameter to be considered for selection of Pulse Oximeter for home use:

SpO2 Accuracy, Resolution; Perfusion Index (PI) accuracy, Resolution. In case of a doubt, you must directly contact the manufacturer of products to provide its clinical performance/evaluation report or other scientific data to support their products accuracy.

A general checklist to select a reasonable quality pulse oximeter.

·         It should have at least reading for SpO2 (accuracy should be greater than +/- 98% or error should be less than +/-2%), PI% (Perfusion Index) and Pulse Rate with a good accuracy. (It should have compulsory PI% reading).

·         It should be from a well-known company or a well-established company. Never purchase those pulse oximeters, where you cannot verify/validate the manufacturer of those products. You might find various cheap products promoted as pulse oximeter on Amazon, Flipkart etc. where no manufacturer details are available.

·         You can prefer those Medical products which have FDA and CE approval.

·         In case of confusion or you are not able to find reasonable/valid/authentic data related to the device, you can contact the manufacturer of that product.

Following is a list of a few Pulse Oximeter, which I found of a reasonable quality based on their product specification etc.

·         Dr Trust USA Professional Series Fingertip Pulse Oximeter Sp02 check (Blue) 202 or Dr Trust USA Fingertip Pulse Oximeter SpO2 check 209

·         BPL SmartOxy or BPL Smartoxy Lite or BPL Smart oxy 03

I will update this list as and when I come across other good quality pulse oximeters.


I would recommend you to always look for certified Medical Devices. Rather than purchasing a cheap low accuracy Pulse Oximeter, it is always recommended to go with quality as these products are measuring something which requires quality output.  In case of low accuracy pulse oximeter, reading taken is equal to a garbage value i.e. of no use. It will work as a toy for you to play with rather than helping you understand the trend of your blood oxygen saturation level.  You may consider any of these two pulse oximeters, either from Dr. Trust or BPL. If you have any questions or want me to further explain any of the points, let me know in the comment section.


Sr. No.Pulse Oximeter NameSpO2 AccuracySpO2 ErrorPerfusion Index AccuracyPerfusion Index ErrorRed Light (nm)IR (nm)
1Medtech Oxygard Pulse Oximeter Oxygard OG0170%~100%±2%; 0%~69% no definition±2%0.2%~1.0%, ±0.2digits; 1.1%~20.0%, ±20%±20%660±3nm905±10nm
2Sansui Fingertip Pulse Oximeter±1% in the range of 90%-99%, ±2% in the range of 70%-89%±2%≤0.6%.   
3Dr Trust USA Fingetip Pulse Oximeter SpO2 check 20970%~100%±2%;±2%Low perfusion down to 0.2% 660nm880nm
4Dr Trust USA Professional Series Finger Tip Pulse Oximeter Sp02 check (Blue) 20270%~100%±3%;±3%    
 Medtech Oxygard Pulse Oximeter Oxygard OG-032%{70%-100%) Unspecified (≦70%)±2%    
5BPL Smart Oxy03±2% (90-100%), ±3% (70-90%), Unspecified: ≤70%±3%  657 – 663nm, 7.0mW900 – 910nm, 55mW














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