MSR145 data logger in a research study at the University of Roehampton, UK

A fall can cause great suffering, especially in older people. The consequences are often broken bones and immobility. Single people in particular are at risk of being left lying down for a long time after a fall if they are unable to call for help.

To counteract this problem, Professor Raymond Y. W. Lee and his colleagues in the Musculoskeletal Research Group at the University of Roehampton have developed and tested a novel smartphone application to address this problem.

Figure 1:

Block diagram illustrating the fall detection algorithm
fall detection algorithm developed for smartphones

Source: A. Carlisle

The British researchers used MSR145 data loggers with 3-axis acceleration sensors to measure and record the signals when a human body falls. The acceleration signals from the data logger are picked up by a smartphone and immediately compared with predefined limit values. The smartphone app sends an emergency signal as soon as a fall is detected. By entering individual acceleration limit values, the "Fall Detection Application" is adapted to the user's personal profile. As soon as a fall occurs, a loud beep sounds automatically and an alarm text is sent to call for help. The diagram below (Figure 1) describes the concept.

External accelerometer vs. integrated accelerometer

In principle, it is also possible to detect falls using an accelerometer already integrated in the smartphone. However, this would require the user to have the smartphone permanently attached to their waist. The problem with this variant is that the user forgets to consistently wear the smartphone on their waist. In addition, false alarms can occur if the smartphone is dropped, affecting accuracy and sensitivity. The use of an external accelerometer (e.g. MSR145 data logger) is therefore considered by the research team to be a better solution. In addition, the acceleration signals of the MSR145 data logger have a higher accuracy than the signals of the accelerometer built into the smartphone.

All details of the research study can be found as a scientific publication in the journal "Age and ageing".