Jeroen Lem

ECG on the Road: Robust and Unobtrusive Estimation of Heart Rate

Modern automobiles include an increasing number of assistance systems to increase the drivers safety. This feasibility study investigated unobtrusive capacitive ECG measurements in an automotive environment. Electrodes integrated into the driving seat allowed to measure a reliable ECG in 86% of the drivers; when only (light) cotton clothing was worn by the drivers, this value increased to 95%. Results show that an array of sensors is needed that can adapt to the different drivers and sitting positions. Measurements while driving show that traveling on the highway does not distort the signal any more than with the car engine turned OFF, whereas driving in city traffic results in a lowered detection rate due to the drivers heavier movements. To enable robust and reliable estimation of heart rate, an algorithm is presented (based on principal component analysis) to detect and discard time intervals with artifacts. This, then, allows a reliable estimation of heart rate of up to 61% in city traffic and up to 86% on the highway: as a percentage of the total driving period with at least four consecutive QRS complexes.

Computer Simulations of the Active Motion System with musculo-skeletal Models

This study concerns the biomechanical computer simulation of the Active Motion system for car seats. This system can impose different kinds of small motions on the pelvis of the driver. Muscle activities were estimated for different parameters for the Active Motion using a musculo-skeletal model in the AnyBody Modeling System. The simulations suggest that a person using the Active Motion will not receive additional loads caused by the feature. Further, the Active Motion system might generate an average relative tension relief within a cycle up to 60 %. This avoids long-term static load, which might postpone or reduce discomfort. The average relative tension relief is most sensitive to pitch and roll amplitudes.