ECG on the road: robust and unobtrusive estimation of heart rate.

Modern automobiles include an increasing number of assistance systems to increase the driver's 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 driver's 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.

Influence of heating car seats on scrotal temperature.

OBJECTIVE: To evaluate the influence of a heated versus an unheated car seat on scrotal temperature under standardized experimental conditions. DESIGN: Controlled clinical study. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Thirty volunteers without a history of infertility and with a normal andrological examination. INTERVENTION(S): Scrotal temperatures were measured every minute with a portable data recorder connected to two thermistor temperature sensors, which were attached on either side of the scrotum. All volunteers started the experiment at the same time of day wearing standardized cotton wool trousers and shirts fitting to body size. Each volunteer performed two periods of 90 minutes in a randomized manner on either the heated or unheated car seat. RESULT(S): At the end of the sitting periods scrotal temperatures were significantly higher using the heated car seat versus the unheated seat (left scrotal side: 0.5 degrees C; right scrotal side: 0.6 degrees C). Maximum values recorded during sitting alone were exceeded on the heated seat already after one-third of the exposure time. CONCLUSION(S): The present study suggests that the frequent use of a heated car seat represents an additional scrotal, and consequently, testicular heat stress factor to that which is present by merely sitting for long periods.