ExoU

Graduation project 2018-2019
Abstract:
ExoU is the graduation project of Lex Biemans, realized in the academic year 2018–2019, under the supervision of Frank Goethijn (Product Development, UA), Stijn Verwulgen (Product Development, UA), and Steven Truijen (Revaki, UA). The ExoU is an exoskeleton (an electrically powered skeleton that is placed over the hand and forearm) that supports stroke patients throughout their entire rehabilitation. Through passive and assisted flexion (closing) and extension (opening) exercises of both the wrist and fingers, patients are given the opportunity to train extra on a daily basis. These additional training hours lead to much higher numbers of repetitions, which increases the chance of recovery of the distal area (wrist and fingers).
Current Situation
As a result of a CVA (also called a stroke), many patients are confronted with hemiplegia (one-sided paralysis of the body). As a consequence of this injury, many CVA patients rehabilitate in a rehabilitation hospital. During their stay/day rehabilitation, they train on average (only) two hours per day with a therapist, due to staffing costs/understaffing. This means that 158 of the 168 weekly hours remain unused. These unused hours are crucial because during the first six months after a CVA, the brain is much better able to take over the lost functions of the damaged hemisphere.
Interdisciplinary Master’s Thesis
In collaboration with students from the Rehabilitation Sciences and Physiotherapy program (Revaki, University of Antwerp), an interdisciplinary master’s thesis was initiated to investigate whether CVA patients gain better rehabilitation opportunities through EMG (electromyography). Myoelectric activity or muscle activity occurs in the muscles when they contract. This activity is measurable and can therefore be used as control for an exoskeleton. It can also provide more insight into a patient’s rehabilitation, for example in the form of an additional means to measure and visualize progress for a patient.
Use
Because the ExoU can be used both passively and in an assisted manner, CVA patients can use the ExoU throughout their entire rehabilitation trajectory. In the subacute phase, when CVA patients generally have little or even no muscle activity, this would occur passively. This means that the ExoU fully bends the wrist and fingers by itself (without patient input). When some muscle activity is present, this can be done in an assisted manner. Using the MYO armband, a product that measures a patient’s myoelectric activity, a self-initiated movement can be directly supported. This makes it possible to rehabilitate much more intensively and actively, because the communication between brain and muscle is stimulated to a much greater extent. In addition, with the support of the ExoU, ADL (activities of daily living) can be trained much faster. Exercises such as picking up objects become possible much sooner, increasing the chance of recovery. The ExoU is lightweight and portable, allowing patients to use it anywhere and without limitation. The availability of therapists is no longer a requirement to be able to perform repetitions, giving patients control over how much they train and thereby providing prospects for (full) recovery. Because the ExoU is largely printed using newly medically certified material, it is cheaper and easily customizable compared to its competitors. This also makes the ExoU interesting for private use.