To speed the recovery of brain injured children using the method of patterning; it must be made efficient. Efficiency can be achieved by automating the manual method, which will provide the patients with the necessary stimuli needed to help them enhance/restore their natural mobility.
This thesis describes research into a novel moderate-cost single-axis Mechatronics device for the remedial treatment of brain injured patients. The device will enhance and/or improve their natural mobility by stimulating the undamaged brain cells responsible for mobility in the central nervous system through physical activity.
A detailed review of rehabilitation robotics was undertaken, covering more than seventy projects relating to disabled people. This review helped to identify the main areas of this research regarding the most suitable structure of the machine and setting up the design specifications for the device. A critical investigation of past and present patterning machines and workstations helped avoid the mistakes made by previous designers in not including brain-injured patients in the initial stages of the design. Use of high technology video equipment has made practicable the development of mathematical expressions based on experimental data for the movements of human arms, feet and head.
Measurements taken and ergonomic data used made it possible to implement a realistic practical novel kinematic arrangement for the patterning machine. A thorough review of direct drive electrical actuators, and surveys and measurements of the human body with respect to the kinematic arrangements, resulted in the selection of the most appropriate actuator for each axis. The selection of the motor and gearbox was based on the mass of each part of the human body in the prone position, the criteria of high peak torque to motor ratio, low cost, minimum maintenance, safety and compatibility.
A computer model of the kinematic arrangement designed was created including the necessary motion constrains, using ADAMS and 3D Working Model simulation packages to test, verify and analyse the static and dynamic stability of the kinematic arrangements and the force interaction between the system and the patient. The simulation results led to some modification in the design regarding the kinematics and dynamic stability of the system by varying different design variables. A walking model of a human was created to simulate the real patient. The model was placed on two units where the feet were the only contact points with the moving belts; the model torso was supported by a harness to hold it in the upright standing position. The results obtained showed the movements of both feet (knees. hips and ankles) in addition to the right and left elbows.
The system hardware was designed and implemented using custom-made safety critical software to control the device to carry out the desired tasks. Safety is considered to be one of the main issues that this research program has developed and implemented. An optimal control strategy was developed to drive the prototype. Smooth movements of the system were achieved through a PD control system enhanced with velocity feed forward gain with position accuracy of ± 0.168 mm. The desired positional accuracy of the Patterner Machine was ± 0.632 mm
