“…Conventional pulse oximeters, being configured as either a transmissive or a reflective type, are based on inorganic light-emitting diodes (LEDs) made of III–V compound semiconductors and Si photodiodes. , However, these systems often require a high power consumption values and emit in the visible region resulting in high tissue absorption. , As an alternative, new reflective type oximeter systems, based on organic LEDs (OLEDs) and organic photodiodes (OPDs) are now being proposed. ,,,,− OLED technology, which is widely used in modern devices, is now rapidly developing in new applications. − Due to its planar structure and the possibility of obtaining a flexible device covering a large area, OLEDs can be used as light sources for oximeters in the reflection mode. OLED’s main drawback is the stability issue, which is not relevant for disposable medical sensors, as in contrast to long-term applications oximetry requires significantly shorter device operating time. , …”