I am trying to figure out why most hospital it still seems to predominantly use fingertip sensor (LED+photodiode) based oximeter for SpO2. I tried searching for example of FDA 510(k) cleared oximeter devices, and there were at least a few dozen (>50) oximeter with fingertip sensor. There are only a dozen or two (at most) wrist sensor based oximeter that are FDA 510(k) approved. There are even less ring sensor and chest patch based oximeter (probably one or two each) that are FDA 510(k) cleared.

Are there any US hospitals that rely on wrist sensor based oximeter? My question is specific to the sensor (LED and photodiode) placement, and not on the placement of electronics itself. For example, Masimo RadiusPPG, Nonin 3150, etc. all use sensor in the fingertip. Oximeter which has electronics in the wrist but sensor coming via. wire to the fingertip is not considered fully wrist oximeter. I am curious to know how commonly do US hospitals use completely wrist (sensor on the wrist), or ring (sensor on the ring) or chest (sensor on the chest) based oximeter devices? Why is this not a clinically acceptable and popular practice?

How does this practice differ in general ward, intensive or critical care unit, out-patient setting, etc.? Does anyone have any survey data or information on this?

  • Presumably the companies that make these devices would be happy to tell you the perceived advantages of fingertip sensors vs. those in other locations.
    – Armand
    Commented Jul 18, 2021 at 23:23

1 Answer 1


All USA hospitals & almost all clinics, use standard pulse oximeters that work by using certain frequencies of red and/or laser light the 1st detects the heart rate by measuring the changes in the difference in brightness/darkness as the beat of the heart pushes fresh blood into & then out of the finger; as that cycling of the blood causes slight variations/contrast that's able to be picked up by the sensor; 2nd, that same laser sensor combination makes use of photoplethysmography, which consists of a light source and a photodetector for measuring transmitted and reflected light signals, therefore determining the blood O² content. The sensors, which come in my shapes/sizes/models, can go on various locations on the body, like the fingers, toes, tongue(used mainly in animals), & other models with brighter lasers can be used on the brachial artery at the elbow region to the arm pit area, & pretty much any place with decent arterial/venous blood flow!

  • 3
    Welcome to Medical Sciences.SE. This seems to be a good overview of pulse ox devices, but it doesn't address the question actually asked.
    – Carey Gregory
    Commented Jul 18, 2021 at 19:46
  • Well, the question asked if we use these various types of pulse oximeters in the US..., and we use a large variety of pulse Oximeters, which come in all shapes & sizes.... But ALL commonly used Pulse Oximeters use the exact same technology..., Because it works, it's been proven, & they are now inexpensive enough that ANYONE, who has $20 - $30 dollars, can purchase a decent, accurate Pulse Oximeter for use anywhere. I don't think I missed anything about this question... But if I have, plz let me know, & I will try to answer it even better, if possible. Thanks Commented Jul 18, 2021 at 20:22
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    Recommend reading the last paragraph of the question. I think that needs to be addressed in an answer.
    – Carey Gregory
    Commented Jul 18, 2021 at 22:49

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