Physiological sensing in a seat environment

Type: Master thesis
Students: Marcel Bächler
Advisor: Johannes Schumm, Marc Bächlin
Project: SEAT

This master thesis deals with the design, the implementation and the testing of a multi-sensor system integrated in an airplane seat which is able to measure different physiological signals unobtrusively. Basic health parameters, such as electrocardiogram (ECG), galvanic skin response (GSR) and respiration provide robust and reliable indicators for the state of health of a flight passenger. The developed Physiological-board is able to record ECG and GSR with a minimum set of only three electrodes at the fingers and the respiration in the safety belt. As the ECG and GSR are measured at the fingers, motion artifacts can easily occur and decrease the signal quality. In order to deal with motion artifacts “smart finger-electrodes” were designed to be able to deal with these motion artifactswith a sophisticated post-process. The measured data can be sent permanently via Bluetooth to a Linux system. Appropriate software filters and algorithms allow the extraction of important features like heart and respiration rates. The captured signal curves can be displayed in Matlab for a convenient visualization, interpretation and for further digital processing. A couple of meaningful measurements were carried out to compare the Physiological-board with a reference device in order to evaluate the signal quality. The effects of different kinds of movements were analyzed to reveal the limits of the system. The proper functioning of the “smart seat” was tested and verified in several experiments with five subjects.