Prognostics and Health Management (PHM) is widely used to study the health state of the system. However, the application of PHM for micro medical devices is a big challenge since they are made up of multiple components which are complex. Prognostics approaches for complex microsystems should be oriented towards identifying critical components and monitoring them individually. This implies the importance of identifying as much as possible the components that can lead to system failures. This work proposes a methodology to select critical components of a micro medical device for PHM implementation. The micro device is a microgripper composed of four components and four steel wires of 0.08 mm in diameter. A risk analysis is performed according to the requirements of ISO standard 14971 for medical devices. This standard provides some techniques that allow to identify some failures modes which affect the behavior and performance of the final product. This work can be seen as a necessary preliminary step before data collection and PHM implementation for such tiny devices. For that purpose, the Failure mode and effect analysis (FMEA) technique is used in order to select critical components. The selection of the critical components is based on a criticality analysis (CA) mainly to prioritize and minimize the effects of critical failure modes that can lead to fault propagation.In addition, some practical guides are presented for PHM development in future works.

This review article provides an overview of some challenges that arise when developing new medical robotic microgrippers. The main challenges are due to miniaturization and are present in the manufacturing and assembly processes, the types of mechanisms, the biomaterials used, the actuation principles, and the compliance with some standards and regulations. The main medical fields where these microgrippers are used are in MIS and biomedical applications. Therefore, taking these two large groups into account, this review presents a microgrippers classification according to the type of mechanism used (traditional rigid-body mechanisms and complaint mechanisms). Moreover, parameters such as applications, functionalities, DOF, sizes, range of motion, biomaterial used, and proposed methods are highlighted. In total, the analysis of 21 microgrippers among commercial and developed by research institutes is presented.