Cost-effective Design of Pulse Oximeter using a Recycled SPO2 Sensor and Arduino Microcontroller

In a quite large number of health care facilities, devices are put out of service after having a serious damage without taking into account making use of their accessories. This paper presents a design of an interfacing circuit that uses a pulse oximeter probe in order to obtain heart rate and oxygen saturation. The circuit was designed to obtain the probe current signal and convert it into voltage, then pass it through two stages of amplification and filtration in order to make it suitable for programming aims. Obtained signal was firstly conditioned, and then it was passed to Arduino microcontroller which was used to calculate and display values of the heart rate and oxygen saturation. The design was tested in terms of output signal, linearity and reproducibility and found to gives an acceptable response results. The circuit designed achieved an important role in making use of unused probes and making an affordable yet an effective device compared to commercial ones. The design's total cost compared to a commercial pulse oximeter device was found to be 1:2.8.