The challenges of utilising inertial sensors for public health measurement. A useful future commodity?

Introduction: The cost of poor health has in recent years caused an extensive economic burden to the state as expensive laboratory measurement methods are heavily relied upon. As we make effort to lower this cost researchers attempt to identify ecological real world techniques, which can monitor health indices on a day to day basis, whilst still having a cost benefit. One such technique which has been identified has been the use of low cost inertial sensors such as accelerometers, gyroscopes and combined units. These units have been successfully utilised in home rehabilitation methods, in silver age technologies to detect falls and extensively in the measurement of physical activity levels across all age groups. Due to their success, nowadays a large market of inertial sensors are available to the researcher or diagnostician with various types on offer in terms of size, site of attachment, data collection type and data output. However, this enhanced choice therefore leads to an increased need to investigate on a sensor-to-sensor basis how feasible specific inertial sensors are when applied to longitudinal data collection. Recently, as part of a larger study, ShimmerTM 2r accelerometer (with combined gyroscope daughterboards) units were utilised in longitudinal data collection with varying results. These units are cased within a lightweight, plastic casing allowing for a robust outer unit, however inner processing board tact switches failed and needed replacement on numerous occasions. These switches provide the on/off switch for the overall sensor therefore leading to loss of data collection periods, vital in longitudinal studies. Along with this the units are decreasingly “user friendly” in terms of data collection procedures compared to other available units and also require an extensive amount of programming knowledge in terms of sensor data extraction and parameter identification. However, the output of raw data, as done with the Shimmer 2r units, can also be a major advantage within data collection as this allows for an extensive amount of versatility in terms of the parameters identified. This also increases the sensors available uses across a range of activities. Conclusions: Whilst inertial sensors will have an increasing role in public health measurement careful consideration must be undertaken when choosing the correct unit. Of vital consideration in the “user friendly” properties of the unit to increase application and validity of results.