Saskia Baltrusch

239 Chapter 9 was mentioned by healthcare professionals and patients was the wish to have a “case-specific” exoskeleton and “different modes for different movements”. Both of these requests imply a device that is versatile, thus can be used for different movements without hindering the user. To be able to switch between tasks in which support is needed and tasks in which maximal movement capacity is desired, without donning and doffing the device, it was chosen to implement a clutch. This clutch can be switched on and off, depending on the task and whether support is needed. Its implementation increased versatility of the exoskeleton, as demonstrated in Chapter 6. Another important design characteristic that healthcare professionals and patients asked for, was comfort. Discomfort is a challenging problem, that limits use in practice of most assistive devices [3]. This is why flexible beams were chosen when building the SPEXOR exoskeleton to preserve the natural range of motion of the user and as a result improve comfort. In addition, as described in Chapter 5, misalignment compensation was also used to align the exoskeleton to the user’s body and minimize the movement between the exoskeleton and the user. For instance, sliders along the leg and along the spinal module move with the user to accommodate for misalignment. This leads to low discomfort when performing tasks, as shown in Chapter 6. The misalignment compensation used in the design of the SPEXOR exoskeleton also allows for a fast donning and doffing, as the device does not need to be adjusted to the user. It therefore provides a “one size fits all”. The time to adjust an exoskeleton at work was a discussion point in the interview with the managers and the focus group with employees. As their job is mostly under time pressure, a fast adjustment of the design is important. Since the SPEXOR exoskeleton still needs to be adjusted at the chest and the hip straps, managers suggested to implement fixed numeric intervals. In that way the adjustment would always be the same and even more time could be saved when it comes to interchanging the device between employees (Chapter 8). Effect on study design The involvement of potential end-users also had an effect on my study design. As shown in Figure 1 and described in Chapter 1, I involved end-users from two potential fields of application: rehabilitation and industry. Chapter 2 revealed the rather negative view of healthcare professionals on using a passive trunk 9