Portable SpO2 Monitor: A Fast Response Approach

Long-term monitoring of human vital signs is becoming one of the most important fields of applied research in biomedical engineering. In order to achieve weeks to months of monitoring, new strategies for sensing, conditioning, processing and communicating have to be developed. While it is relatively easy to monitor some medical parameters at rest, getting reliable measurements and diagnosis during periods of physical activity is very difficult. This is especially true in the case of non-invasive methods, where monitoring techniques are very sensitive to various artefacts appearing when the person is active. Successful results were obtained at the Swiss Center for Electronics and Microtechnology (CSEM) fusing data from different sensors. The key technology resides in sophisticated signal processing approaches for such multi-parameter systems, including advanced signal processing algorithms and low-power implementation on real-time platforms. CSEM has designed and developed a so-called opto-inertial sensing platform to continuously measure physiological signals, such as heart rate (HR), blood oxygenation levels by pulse oximetry (SpO2) and presently blood pressure (BP). This paper presents the essential issues in applying CSEM's opto-inertial sensing platform for the development of portable hemodynamic sensors.