Health issues for elderly people may lead to different injuries obtained during simple activities of daily living. Potentially the most dangerous are unintentional falls that may be critical or even lethal to some patients due to the heavy injury risk. In the project “Wireless Sensor Systems in Telecare Application for Elderly People”, we have developed a robust fall detection algorithm for a wearable wireless sensor. To optimise the algorithm for hardware performance and test it in field, we have designed an accelerometer based wireless fall detector. Our main considerations were: a) functionality – so that the algorithm can be applied to the chosen hardware, and b) power efficiency – so that it can run for a very long time. We have picked and tested the parts, built a prototype, optimised the firmware for lowest consumption, tested the performance and measured the consumption parameters. In this paper, we discuss our design choices and present the results of our work.
for Smartphone-based Activity Tracking”, Presented at Proceedings of the International Conference on Health Informatics , 2012.  Shin, J., Shin, D., Shin, D., Her, S., Kim, S., Lee, M., “Human Movement Detection Algorithm Using 3-AxisAccelerometer Sensor Based on Low-Power Management Scheme for Mobile Health Care System”, Presented at GPC'10 Proceedings of the 5th international conference on Advances in Grid and Pervasive Computing , May. 2010.  Kwapisz, J. R., Weiss, G. M., Moore, S. A., “Activity Recognition using Cell Phone Accelerometers”, ACM SIGKDD
. In addition to the electrophysiological readings, the acceleration was measured and recorded by two 3-axisaccelerometers with a range of 24 g and 2 g , respectively. The measurement units controlled the applied voltages, measured the corresponding current and effective applied voltage, switched the valves controlling the media flow and the top pressure, and recorded the temperature in the recording chambers. While still on the ground, the units could also switch on heat foils under the recording chambers in case the temperature of the recording chambers dropped