ABSTARCT
In today’s society individuals suffer from an array of health problems, such as cardiovascular diseases, hypertension, diabetes and congestive heart failure. These conditions are primary drivers for the development of wearable and mobile health monitoring technologies that offer the potential to (a) increase the quality of life for individuals that already suffer from these health conditions and (b) prevent or mitigate the onset of diseases in those that are at risk to acquire these health issues. The most promising wearable health monitoring device is the pulse oximeter, since it gives both the oxygen saturation level and the heart rate measurements.

INTRODUCTION
A pulse oximeter is a very important medical instrument that is used to measure the amount of oxygen in blood. It is used in operating rooms, recovery rooms, intensive care units(ICU), neonatal care units(NICU), …show more content…
Since invasive method of oxygen saturation measurement could not yield fast and timely results, the pulse oximeter, which is a non-invasive way of measuring blood oxygen level, was invented by Karl Matthes in 1935. Since its invention, the pulse oximeter has undergone constant changes and modifications.

LITERATURE REVIEW
Beer- Lambert law:
This law relates the attenuation of light to the properties of the material through which it is travelling.
The law states that there is a logarithmic dependence between the transmission T, of light through a substance and the product of the attenuation coefficient of the substance, Σ, and the distance the light travels through the material (i.e., the path length), ℓ. The attenuation coefficient can, in turn, be written as a product of an absorptivity of the attenuator, ε, and the concentration c of attenuating species in the material. It is given as: It=I0*10εcd

Oxygen saturation,