Activity sensor
An activity sensor or movement meter is a small electronic device used to measure and record physical movement over a long period of time. The measurement is based on an integrated acceleration sensor, which measures the acceleration on the body where the sensor is attached.
History and Development
The first activity sensors came onto the market in the USA in the 1980s and were able to measure acceleration on the body in one and two dimensions . Newer devices measure three-dimensionally in all spatial axes. Since the middle of this decade, the technology has also started to spread in Europe . So far it has mainly been used in research and medicine for studies, but mass distribution as a daily energy consumption meter and movement meter is to be expected as soon as the prices of the devices, which often cost several hundred euros, fall.
Working method
The devices derive different activity classes or zones from the acceleration measurement. Many US devices differentiate between light, moderate, and strong movement. European devices, on the other hand, distinguish, for example, active movement (without steps) and different running speeds as classes (slow, fast, sporty) or lower and higher activity zones according to the intensity of the movement. For example, are displayed in the reports
- Daily profiles of physical activity
- power consumption
- Number of steps
- distances covered
- Height measurement
User-related values such as height , body weight , age and step sizes must be set in the device beforehand. The number and level of detail of the evaluations differ for different devices. There are different concepts in product design. Some devices are worn on the upper arm or wrist , others on a belt. According to scientific studies, wearing on a belt brings the most accurate measurement results, as the measurement point is closest to the body's center of gravity . Activity sensors can record a very wide range of measured values. In addition to activity and step counting, some devices are also able to calculate distances traveled and the nutritional energy consumed by physical activity . If step counting is integrated, it is much more accurate than with conventional step counters , as it also enables very slow and small steps to be recorded. Activity sensors record the activity in the internal memory over several days. Some have a small display , with other devices the recorded data must be transferred to a PC in order to be evaluated. Some of the devices designed for medicine have an integrated telemetric transmission option - for example via Bluetooth - so that recorded values can be transmitted directly to the doctor, supervisor, telemedical center or hospital.
