Microcontroller based pulse oximeter for undergraduate capstone design

Pulse oximeters are used worldwide as a non-intrusive way to monitor a patient´s pulse and blood-oxygen saturation instantaneously. The purpose of this design is to examine the possibility of using a simple microcontroller to measure pulse and blood-oxygen saturation in real time, as well as the level of difficulty and learning curve associated with assigning such a task as a senior capstone design project. The circuit consists of a PIC18F452 microcontroller, transistor network, photoplethys-mogram amplifier (PPG), pulse oximeter probe, digital-to-analog converter (DAC), and an LCD screen to display results. Software is written in C++ for the microprocessor, which supports a limited C syntax. The project requires various engineering proficiencies such as signal processing, programming, circuitry, and microprocessors. Overall, the project is a good introduction to medical instrumentation and capstone design for undergraduate biomedical and electrical engineers.