Implementation of a wireless pulse oximeter based on wrist band sensor

In order to develop a wrist band pulse oximeter, the detected light intensities and effective transmission depth of reflectance oximetry are investigated by analyzing the light propagation through tissue. A reflectance probe is fabricated based on the analytical results. An oxygen saturation measurement system is also implemented and some preliminary experiments are conducted. The experimental results have confirmed the feasibility of this wrist-band oximeter. Home healthcare can be ensured by transmitting the realtime measurements through wireless technology to the community monitoring system.

I. Introduction

Non-invasive pulse oximetry has been widely used in clinical care for critical ill patient, monitor of patient during the anesthesia in operations, research of breath state while sleeping, etc. It's a safe, reliable, real time and continuous measurement method. Nowadays transmittance oximetry has been fully developed and there're many mature products which are widely and frequently used in hospitals. However, a transmittance pulse oximeter is reliable and practical only in case the patient is hospitalized or lying steadily. Besides, transmittance measurements sometimes cause discomfort, pain or injury because its sensor lightly presses a finger or ear lobe and occasionally blocks the blood flow. A reflectance oximeter which increases the flexibility of installation can avoid such problems and meet the needs of modern home healthcare, whereas the research of reflectance oximeters is still in a shortage relative to the transmittance type and there are few complete solutions for reflectance oximetry[1][2].