Design an Upper Body Exoskeleton to Facilitate the Child’s Arm Movements and to Mitigate against Scoliosis (Curved Spine)

"If I have seen further than others, it is by standing upon the shoulders of giants" ~ Isaac Newton. 

Recognizing the significance of this statement, I wish to express my gratitude to God for providing me with the strength to undertake this challenging but fulfilling task, to my supervisor, Dr. Jacqueline Bridge, the esteemed Head of the Mechanical and Manufacturing Engineering and the technical/teaching staff at the Faculty of Engineering including: Mr. Bandoo, Mr. Lionel, Mr. Prime, Mr. Cadet and Mr. Ramnarace. I am indebted to my family, friends (Jonathan, Sylvan, Zakiya & Kayla), mentors, former neighbours and well-wishers for their religious support. To the client, Dr. Nathai Balkisoon thank you for your hospitality. 

The objectives of the report were to provide a comprehensive review of the theory, application, and recent developments in exoskeleton design and to design, fabricate, code and test a proof-of-concept model (shown in Figure 1) of an upper body exoskeleton taking into consideration factors such as cost reduction, ergonomics, and safety. The rationale for the project were to mitigate the barriers to accessibility of assistive devices to the differently abled community in Trinidad and Tobago due to in part to prohibitively high procurement costs, and the need for a robust design process which can be adapted to develop other assistive devices. The subject of the report was Emma, a now 9-year-old child who suffered a traumatic brain injury during infancy and as a result presents with multiple disabilities including limited motor skills, hyperextension of the arms, scissoring of the legs, low muscle tone in the neck and torso, scoliosis and low bone density.

To develop the model, her anthropometric measurements were recorded, with bony prominences being used as body markers to ensure the repeatability of results. Thereafter, strength calculations and simulations were performed to optimize the model. Due to factors including time and the availability of materials, the model was fabricated using a combination of 3D printing, machine shop operations and carpentry. Additional modifications were made to the proposed design based on practical considerations. 

Although the minimum requirements of client were achieved including cost reduction (total cost $631.74 TTD), compactness, flexibility for growth and aesthetics, the design was not ergonomic/safe enough to be tested with a human subject due to problems with the structural integrity of the rigid parts.  Additionally, acceptance testing of the model demonstrated that it functioned better with increased load as the effects of gravity allowed the exoskeleton arm to be more quickly restored to its rest position. However, the positional accuracy test yielded inconclusive results as the system response did not follow an observable trend. The model's functionality can be improved through the selection of more durable material such as carbon fibre to fabricate the rigid components and the addition of a PID controller for more accurate position control.