Through the research on the target user - stroke patients, collaborator Dr Ijana Jevtic Vojinovic and I have decided to design a rehabilitation tool attached to the human body inspired by exoskeleton and body coordination. Therefore, in the first stage, I have done a 3D scan with my upper half of the body for design reference. As this is an accessible rehabilitation tool that aims to target many stroke patients, modular design and universal design are more suitable for this project basis.
This project also focus on lower the number of parts and simplify structures while achieving the same workability and functionality. Many experiments were done with print-in-place design concerning the qualities of design for additive manufacturing. Without a dual nozzle printer and changing flexible filaments (i.e. TPU/Ninjaflex), I tried to separate bodies to allocate different print setting (i.e. infill patterns and top/bottom thickness) to create more flexible parts in a single component for the potential use of hand strap.
Through compliant mechanism, the whole system of mechanical design, components and materials could possibly be simplified. Simplification can improve the intuitiveness of modular design as it creates less errors when it is adjustable and interchangeable. In order to achieve continuous rehabilitation for user’s motivation, the gear is interchangeable according to the flexibility of spring, which implies the level of difficulty in the joint rotation. Other than the gear system for the joint, gear pulley is also created for collecting different joints, different length of rubber band is used to accommodate the hand size and arm span for different gender and body size. For example, the cases studies mentioned previously shown a variety of body condition.
REHAP aims to complete the synchronoisation of movements on both sides of the body. The ease of use for stroke patient should be further explored as the patient needs to wear the component on both hands; the help from caregiver may be required in this stage. Wearing as a sleeve is the main direction to simplify the instructions and enhance the comfort for the user. I tried to separate bodies to allocate different print setting (i.e. infill patterns and top/bottom thickness) to create more flexible parts in a single component.