Prototyping a stable pulse oximeter

Abstract

Pulse oximeter has become an essential medical device in the modern practice of emergency department in a hospital for its ability to provide convenient, non-invasive and continuous monitoring of oxygen levels in a human body (1). By constructing the pulse oximeter from scratch, the author was able to build a highly customizable pulse oximeter in terms of functionality. Implementing LabVIEW in operating this pulse oximeter provides superior versatility in modification process.

The author tested different formulas from both Beer-Lambert law and clinical empirical formulas to determine the calibration standard for this pulse oximeter. It is found that clinical empirical formula offers more accurate calculation of oxygenation, as there are significant issues those are not taken into account in Beer’s law, which will be elaborated in the text. Readings show that the prototype pulse oximeter is able to measure SpO2 in the range of 85 to 100% within ± 4.76% accuracy and standard deviation of 4.12%. In vivo experiment also conducted to show that the prototype pulse oximeter can properly measure changes in human heart rate, which in this project was triggered by Valsalva maneuver.