Pulse oximeter uses which has internal LED photodetectors, optical elements and low-noise electronics with ambient light rejection. Because of its compact nature, it can also be set to work in wearable, mobile devices. The IC operates on a single 1.8 V power supply and a separate 5 V power supply for the internal LEDs. The communication is through a standard I2C interface. The module can be shut down through software with 0 stand-by current, allowing the power rails to remain powered at all times. The oximeters can be used in measuring blood oxygen levels of the wearer. And with the circuit, the readings can be sent directly sent to the user’s phone, or the doctor’s too.