Alternative method to demonstrate the structural integrity of lower limb rehabilitation exoskeleton

One of the primary challenges in exoskeleton design is the testing of physical human-exoskeleton interactions (pHEI), an area that has received limited attention in the existing literature. pHEI measurements are defined as any extraction of information related to forces exchanged between a human and an exoskeleton during the execution of a task. Unfortunately, there is currently a lack of standardized methods for measuring these loads, highlighting a clear gap in the definition of protocols and assessment procedures. Compliance with the EN 60601-1 standard, which outlines general requirements for basic safety and essential performance of medical electrical equipment, is often required for the commercialization of such devices in many markets. As stated in EN 60601-1:2005 Section 9.8.2: "The tensile safety factors must not be lower than those specified in Table 21, unless an alternative method can demonstrate the structural integrity throughout the expected service life of the equipment or if the support is at foot rest." The aim of this thesis is to present the alternative method that has been studied and evaluated by the candidate to demonstrate the integrity of the ABLE Human Motion lower limb rehabilitation exoskeleton and ensure compliance with the existing standard. To determine the loads that the exoskeleton should withstand, various tests were conducted, and the results were then used to verify the structural safety through structural simulations. This work will outline the experimental process of determining the loads, starting from the candidate's initial study. It will show the conceptual and practical development of the project, beginning with the analysis of motion during the normal use of the exoskeleton. The load cases will be elaborated and used to construct the structural simulations. These, along with mechanical verifications and calculations on the entire structure, form the alternative method used to verify the structural integrity of the ABLE Exoskeleton, ensuring compliance with the EN 60601-1 standard for Medical Electrical Equipment.