Table 5

Reported problems with accelerometer hardware and software in health research

Hardware problemsSoftware problems
Derived categoriesFindingsDerived categoriesFindings
Battery problemsBattery problems were quite frequently reported. Battery life shortens over time and during cold weather periods, resulting in problems of data collection and data loss.Lack of user-friendlinessSome users felt that often too many steps were necessary to process the data.
Packages running in the R software environment (GGIR, accelerometry) were repeatedly reported as being too complicated to use.
Compliance issuesAnother frequent problem. Compliance is reported to differ by placement, and consequently by device with best compliance in wrist-worn devices.
Also, skin irritation has been reported. Children are especially prone to non-wearing uncomfortable devices, and to loss of devices. Moreover, children in a classroom setting will swap devices if not labelled.
Limited possibilities of softwareOnly a limited number of settings is available with shelf software.
Data lossData loss due to technical failure was reported frequently, without giving specific causes. In some cases, the manufacturer was able to rescue the data.Software bugsSoftware bugs were reported in varying detail. No general finding.
Mechanical problemsThe accelerometer casings, the wrist straps, and other mechanical components were frequently reported to break.High computational burdenHigh time complexity was repeatedly reported to be a problem with the Actilife software.
Electronic problemsThere were some reports on faulty internal clocks, memory and Bluetooth issues.Black box character of softwareData processing of software is not well documented, as a result the software appears non reliable to the user. This also poses a problem for scientific reporting as exact procedures are not known.
Sensor problemsFaulty signals, filtering or calibration issues were reported infrequently.
Lacking waterproofnessLack of waterproofness is a problem, especially when active swimmers are in the sample. Some reported that they would manually add the activities to the derived parameters, which is cumbersome.
OtherLack of comparability between devices, bankruptcy of one device manufacturer. General doubts on validity of the devices.