Pulse oximeters are of critical importance in emergency medicine and for the diagnosis of patients with respiratory and/or cardiac problems. There are dearth of pulse-oximeters in the market, some get sold by mere brand name and other's devices, clinical practitioners cannot distinguish between other competitive products when some of these products have similar(even exact) performance as cheaper ones, few last longer and comparable with watches and applets, and this is because such devices implement exactly the same methodology. This paper is a good synopsis of clinical theory and presents the physiologic limitations of oxygen saturation monitoring even by clinical grade pulse oximeters. This paper bring into light the practical challenges and highlights what makes a device inaccurate or a reliable device and a clinical grade oximeter, essential performance in compliance with standards, and how can even an expensive device readings can be erroneously interpreted or show discrepancies and errors.
