Application of TRIZ Methodological Tools for Wearable Device Design Using Low-Cost Off-the-Shelf Sensors

Currently, there is a widespread use of inertial motion units (IMUs) based on micromechanical systems (MEMS) with applications ranging from consumer electronics to medical devices. One of the main uses of this technology is in human body motion capture systems, which require attaching various IMUs to the body. It is customary to start the design of IMU-based motion capture solutions by using generic off-the-shelf (OTS) solutions or custom integrations. However, it is common that generic OTS solutions or custom IMUs integrations are not necessarily intended or designed to be directly attached to the human body. To address this issue, a widely adopted solution is to perform quick workarounds to enable the IMUs to be “worn” by prospective users. However, this can have the drawbacks of increased probability of detachment, improper fit, user discomfort, adding noise to the IMU measurements, etc. Therefore, the development of OTS IMU-based motion capture solutions would greatly benefit from having a methodological approach for the design of device housings and/or adaptations for OTS solutions or custom IMU integrations, such that they can be effectively used as wearable devices. In this work, we introduce a design methodology for wearable devices based on the Theory of Inventive Problem Solving (TRIZ). By designing a “wearable device housing” for an OTS IMU solution, we show that the proposed TRIZ-based methodology provides a straightforward and structured approach for the design of wearable devices. Furthermore, we illustrate how various challenges encountered in the early stages of prototype development can be effectively addressed using this methodology. The results obtained with the study case confirm that the proposed TRIZ-based methodology effectively overcomes the challenges associated with the design of wearable devices based on generic OTS solutions or custom IMU integrations.