A mechanism for elbow exoskeleton for customised training.

It is well proven that repetitive extensive training consisting of active and passive therapy is effective for patients suffering from neuromuscular deficits. The level of difficulty in rehabilitation should be increased with time to improve the neurological muscle functions. A portable elbow exoskeleton has been designed that will meet these requirements and potentially offers superior outcomes than human-assisted training. The proposed exoskeleton can provide both active and passive rehabilitation in a single structure without changing its configuration. The idea is to offer three levels of rehabilitation; namely active, passive and stiffness control in a single device using a single actuator. The mechanism also provides higher torque to weight ratio making it an energy efficient mechanism

Automatic splint to prevent self-harm in autistic and brain injured people

This dissertation is aimed at providing a less restrictive alternative to applying restrictive splints to people who display self-injurious behaviour often seen in people with severe autism or brain injuries. An electronic method of controlling an elbow jointed splint is explored, designed, built and tested. The final product, the Dynamic Splint Device (DSD) is a self-contained electronic joint that utilises an electromagnetic brake controlled by an Arduino microcontroller electronics board. Sensors measuring elbow joint rotational velocity, total fist acceleration and bending moments are used to predict potential impact forces. The device will reduce injury by applying a braking force to the joint when the predicted impact is greater than an adjustable set-point. The electronic ratchet developed as part of the braking system has allowed a sense of not being restrained, as the arm is not restricted from moving to a more open position. The ratchet has also increased the battery life of the DSD. Legally, restraints are required to be the least restrictive available. The DSD has the potential to revolutionise the care of people displaying Self Injurious Behaviour (SIB) by reducing the need for full restraint. It allows movement in a safe manner, restores civil liberties, and allows better therapy when compared to full restraint devices currently available on the market. Allowing health professionals and carers to build this device is integral to the design. Open source coding, 3D printable parts and off the shelf components allows anyone with a computer and a 3D printer to make the DSD, with the only limitation being that profit is not made

A Study on Active/Passive Pneumatic Actuators for Assistive Systems

The need for intelligent assistive devices is growing. Due to advances in medicine, people are living longer and able to recover from severe neurological incidents, resulting in an increased population with neuromuscular weakness. In workplaces such as assembly lines, there is a high possibility of work-related fatigue or injury, such as when workers squat down or lift their arms during their work tasks. Assistive devices could help remedy loss of strength on their extremities as well as keep the work environment safe and productive, allowing these growing segments of the population in need of the devices to live more self-sufficient, productive, and higher-quality lives.In the design of assistive systems, an important design goal is prolonged operational time, which requires the minimum usage of energy. Energy consumption can be reduced by modifying the mechanical characteristics of assistive systems according to the dynamic characteristics of the human body, which vary considerably between tasks. This dissertation investigates 1) the design of actuators with adjustable mechanical impedance, 2) control strategies to search for, and adjust to, a suitable mechanical impedance for assistance and 3) sensing technologies for classifying the tasks in which the human engages.The first part of this dissertation characterizes a pneumatic variable stiffness actuator named an Active/Passive Pneumatic Actuator (AP2A). The actuator consists of an air cylinder and an array of solenoid valves. These valves and the corresponding switching algorithms tune the chamber pressures and make the AP2A function as a mechanical spring with desired stiffness. The actuator has a low mechanical impedance compared to geared motors, which enables it to achieve efficient interaction. Control strategies of an assistive system with the AP2A are discussed in the second part. This control framework utilizes the characteristics of the AP2A to provide assistance when necessary and to operate transparently (i.e., neither to assist nor to disturb the users) otherwise. Energy consumed by the AP2A and the assisted system is minimized by solving an optimal control problem. Finally, an estimator is introduced to detect assistive timing for the assistive system with the AP2A. This estimator utilizes physiological signals such as surface electromyogram and prior knowledge of a muscular model, classifying if the user is under the specified condition to be assisted by the AP2A. It demonstrates that the user's effort can be saved, also reducing the number of procedures to collect training data for the estimator before using assistive systems. The performance of the actuator, the controller, and the estimator proposed in this dissertation are verified through experiments.From the above, this dissertation contributes to developing the AP2A that provides assistance and saves energy usage of assistive systems by working as a mechanical spring with stiffness optimized for achieving effective interaction under specific conditions. This actuator supports assistive devices that can be deployed in the real world, properly assisting the users when needed

Stretchable Surface Electromyography Electrode Array Based on Liquid Metal and Conductive Polymer

Electromyography (EMG), the science of detecting and interpreting muscle electrical activity, plays a crucial role in clinical diagnostics and research. It enables assessment of muscle function, detection of abnormalities, and monitoring of rehabilitation progress. However, the current use of EMG devices is primarily limited to clinical settings, preventing its potential to revolutionize personal health management. If surface electromyography (sEMG) electrodes are stretchable, arrayed, reusable and able to continuously record, their applications for personal health management are broadened. Existing electrodes lack these essential features, hampering their widespread adoption. This thesis addresses these limitations by designing an adhesive dry electrode using tannic acid, polyvinyl alcohol, and PEDOT:PSS (TPP). Through meticulous optimization, TPP electrodes offer superior stretchability and adhesiveness compared to conventional Ag/AgCl electrodes. This ensures stable and long-term skin contact for recording. Furthermore, a metal-polymer electrode array patch (MEAP) is introduced, featuring liquid metal (LM) circuits and TPP electrodes. MEAPs exhibit better conformability than current commercial arrays, resulting in higher signal quality and stable recordings, even during significant skin deformations caused by muscle movements. Manufactured using scalable screen-printing, MEAPs combine stretchable materials and array architecture for real-time monitoring of muscle stress, fatigue, and tendon displacement. They hold great promise in reducing muscle and tendon injuries and enhancing performance in both daily exercise and professional sports. In addition, a pilot study compares MEAP performance in clinical electrodiagnostics with needle electrodes, demonstrating the non-invasive advantage of MEAP by successfully recording the signals from the same motor unit as the needle. These advancements position MEAP at the forefront of the EMG field, poised to drive breakthroughs in electrodiagnostics, personalized medicine, sports science, and rehabilitation