Modern automobiles include an increasing number of assistance systems to increase the drivers safety. This feasibility study investigated unobtrusive capacitive electrocardiogram (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 whilst driving show that travelling 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 4 consecutive QRS complexes. (Author/publisher)
Samenvatting