EXPLORE - THE TRAVAILS OF A PERSON WHO CANT USE HIS HANDS

WHY CAN'T WE DO BETTER THAN WHAT WE HAVE IN THE MARKET NOW?

WHO IS WILLING TO SHARE HIS KNOWLEDGE? LETS CREATE A KNOWLEDGE CENTRE

This is my work so far over the past 6 months. References available on request.

INTRODUCTION & BACKGROUND


Over the past 30 years, statistics has shown the rapid increase in the cases for stroke and spinal cord injury patients in Singapore and in ASEAN. Increasing the demand of Rehabilitation professionals alone is not a ready solution as the duty and responsibilities assigned to the therapists have greatly increased. There is a strong need to develop an efficient and effective automated Upper Extremity (UE) functional training orthosis that would greatly benefit stroke patients to provide customized and accelerated rehabilitation. An important potential benefit of using robotics and information technology for neurological rehabilitation evaluation is that it permits new measurements that will provide deeper insight into the severity of impairments or degenerations and the sensory motor consequences in patients with neurological impairments (Roher, 2002; Finley, 2006). Many researchers of developing UE robotic trainer have shown promising results, eg. MIT-Manus, MIME and ARM Guide. The first robotic therapy study was conducted with MIT-Manus, confirmed that robots could be used as effective tools to aid in rehabilitation of movement deficits by increasing the amount of therapy delivered to acute stroke patients (Leonard, 2003). When compared to conventional treatments, robot-assisted therapy resulted in larger gains in strength and larger increase in reach extent (Leonard, 2003). However none of existing systems are portable or easy to wear. It is for these reasons, that this project aims to develop a unified UE rehabilitation orthosis platform to address the current short comings.

Research proposal

Our hypothesis is to help acute stroke patients to acquire a better and more functional recovery through the use of robotic technology with the proper design of a customised orthosis.
Results from many research & patients feedback is that patients desire for recovery of their upper limbs functions (in terms of grasping, wrist and forearm control) are the most important function for them so that patients can perform their Basic Activities in Daily Living (BADL).
The aim of this project is to develop a Unified platform to achieve Accelerated Functional Return of Grasping, Wrist and Forearm Control in Stroke Patients with EMG Actuated UE Orthosis.
When we combine the use of the robotic technology with the proper design and use of the orthosis, we can help acute stroke patients to acquire a better and more functional recovery. The final efficacy of such a proposed system can be measured by using FIM and Fugl-Meyer assessments for functional outcomes.
The research will be working closely with the senior therapist and Rehabilitation Physicians at TTSH rehabilitation centre as well as to gain access to their ready source of stroke patients. An international expert Professor of Rehabilitation Engineering from SMI have been brought on board as a co-investigator to allow the team to leverage on his expertise in this area. It is the aim of this project to allow Singapore to establish and gain expertise in the area of robotic assisted active rehabilitation which is currently not available in Singapore. As the population of Singapore and that of the region steadily ages, this is an area of concerned which should be addressed with urgency.

Clinical Significance

Current literature shows that a lot of work has been done on lower limb orthosis but comparatively less on upper extremity, especially orthosis for grasping and pronation / supination. Data from TTSH, speaking to stroke patients and information published from various research papers indicates that the most important function that the patient wishes to recover urgently after a stroke episode is that of grasping, wrist and forearm control, so that they can be self sufficient in feeding, bathing, and clothing themselves as well as being able to resume handling visits to the toilet alone.

We find that after extensive literature review that a lot of work has been done on FES-based systems, patient activated virtual reality systems, different types of rehabilitation protocols ( eg. Restraining unaffected arm ) and so on. All the above have had their positive results in their own ways and have contributed greatly to the understanding of motor and neuromuscular rehabilitation.

However, there has been very little work done in trying to bring together on a single platform all the critical elements of the studies conducted, so that the orthosis is versatile, simple, affordable, and effective.

According to several works on rehabilitation by various researchers, the key elements of recovery in rehabilitation should include :

1. Ability to generate an isometric preactivation of sufficient strength voluntarily
2. Ability to perform complete functional ROM for each joint
3. Ability to generate sufficient force in grasping action and other movements
4. Recovery of functional capabilities rather than isolated movements eg. Feeding oneself while holding a spoon, tracing a pattern with fingertip, combing hair, picking up and placing objects, etc.

Preliminary Data

Currently in the market, there are the NeuroHand and NeuroMove available for UE FES and EMG based UE training. The NeuroHand incorporates FES and a forearm based (covers up to the wrist joint) hand orthosis. There is a controller box which can adjust the frequency and amplitude of the FES. It provides stimulation to the wrist and finger extensor and flexor muscles once the FES has been turned on with a specific frequency alternating between flexion and extension of the wrist and fingers. It is mainly used for training but no voluntary control of activating of the device by patients themselves. E.g. They cannot hold the flexion of the wrist and fingers as long as they want once the FES starts to stimulate the extension muscles and the hand orthosis only covers up to the wrist. As a result, stroke patients tends to develop a lot of flexor tone over the affected side of the body only. Once the FES activates the forearm extensor muscles, the fingers tend to hyperextend at the MCP joints due to the strong pulling from the flexor muscles. Hence it does not really prevent fingers flexors from further contracting. For NeuroMove, it is a machine that functions based on EMG and FES. The EMG electrodes will be placed on the forearm to detect muscles contraction. From there, the machine will pick up the signal and activate the FES electrodes which is also placed on the forearm to stimulate extensor or flexor muscles. However, there are no hand orthosis to compliment for proper hand positioning during the training.

Methodology

The proposed orthosis will be ergonomically designed. The orthosis will also have the dynamic feature to accommodate the movements of the joints. It will consist of as few parts as possible. For example, if a patient is able to control his proximal UE movement, he then can start with wearing the next distal part of the orthosis for support. The converse can also be true. If the distal movements are recovered first, the orthosis modules for distal function can be discarded and the subsequent proximal module can be worn. As the rehabilitation progresses and the patient improves further, additional parts can be either incorporated or discarded. In this way, the patient will just need to put on the additional pieces for the next stage of training. The proposed orthosis is based on the principle of detecting SEMG of corresponding muscles and then triggering actuators or FES stimulation to facilitate muscle activation of the affected site.
From the above, it was decided to design the robotic arm UE orthosis along the following lines :
1. It should read and record an isometric contraction through SEMG electrodes. If no isometric contraction can be generated by patient, the patient should trigger a FES signal to stimulate the muscle isometrically.
2. It should allow the voluntary movement through complete functional ROM. In case the patient is unable to generate movement, it will be generated by FES or mechanical actuator or both in parallel. The FES and actuator will be triggered by the SEMG or some such trigger which can be controlled by patient. The quality and frequency of the trigger will dictate whether the ROM achieved is partial or complete.
3. The force generation may be supplemented by the FES or actuator.
4. Visual Feedback on a computer screen may indicate which muscles are contracted and how much force is generated. This will be a Boolean display read from SEMG amplitude and frequency of the contracted muscle and will only be indicative for the patient to direct attention to required muscle groups. There may be a benchmark provided based on readings from the unaffected arm.
5. For functional movements contributions from other joints may be assisted manually during testing or automated by add-on plug-n-play attachments for elbow and shoulder ( as part of future work ).
6.The design and construction of the robotic brace will be ergonomically and anthropometrically aligned to reduce unwanted compensation and fatigue.
7. The design and construction of the robotic brace will be light, simple and easy to use at home independently by patient after initial training.
8. The triggers are to be independently adjustable for each channel so that they are applicable to a large cross-section of patients. The patient should be able to independently switch on / switch off the FES and / or actuator, based on progress.
9. The design will be modular, so that after rehabilitation is complete, any or several modules can work as an assistive device depending on which movements are recovered by patient and which are not. Also the patient can move into long term rehabilitation of these movements at home.
10. The combination of FES / mechanical actuator will enable the therapist and patient to balance the continuous loading of muscles with fatigue relief when required. This will enable many more hours of rehabilitation and many more repetitive movements thus enhancing neuromuscular retraining and also preventing muscular disuse atrophy.