Title: Mechanical Muscle Activity with Real-time Kinematics (M-MARK): A novel combination of existing technologies to improve arm recovery following stroke
Funder: Department of Health and Social Care

Abstract: About 150,000 people in the UK suffer a stroke each year and ~60% with moderate to severe stroke fail to recover arm or hand use. Stroke rehabilitation is increasingly home-based following early discharge from hospital to facilitate self-management and avoid problems associated with prolonged hospital stays. There is strong evidence that intensive practice and re-education of normal movement is essential for functional motor recovery, hence the NHS guideline of 45 minutes therapy 5 days/week, but NHS Trusts have difficulty meeting this target due to cost and access to specialist therapists. Our aim is to develop a low-cost wearable wireless device that patients can use independently at home while practicing standardized everyday activities to regain upper limb function. M-MARK will incorporate feedback, presented on a computer/tablet, as motivating visualizations of movement showing them if they have moved in the correct way &ndash; such as reaching by extending their arm rather than leaning forward, and using their arm muscles efficiently. The same device, but with different software and interfaces, will satisfy the needs of therapists for a simple system to diagnose specific movement problems (e.g. reduced range of movement or uncoordinated activity between muscles), to inform clinical decision-making, monitor progress and thus increase efficiency and effectiveness of therapy. This is particularly important now in prescribing new therapies, such as botulinum toxin for spasticity and constraint therapy for learnt disuse that demand differential diagnoses. Accurate assessment is critical for effective rehabilitation and understanding recovery. M-MARK will provide information at all 3 levels of the International Classification of Functioning, Disability and Health6: body function (muscle activation), activities (kinematic limitations) and participation (overall activity during everyday life). This is currently not achieved by laboratory tools or clinical assessments. Achieving our aim: Commercially available inertial measurement units (IMU) can accurately record movement yet are rarely used clinically; one reason may be that although they provide data on amount of arm use, they currently do not provide information about quality of movement. Electromyogram (EMG) to record muscle activity has been available for many years but is rarely used by therapists. Mechanomyography (MMG) is an alternative to EMG that measures muscle activity using a sensor to detect vibration. MMG is easier to use than EMG because it does not require electrical skin contact or precise positioning. MMG does however demand advanced signal processing techniques to deal with artifacts. By integrating IMU and MMG data we will generate measures of quality and quantity of movement and present them on a computer/tablet in forms suitable for patients and therapists. The potential benefits of the device are that patients will be motivated to practise and encouraged to relearn normal movement patterns, and therapists will have the ability to quantify and classify movement and muscle activity impairments that interfere with functional tasks, which will enable them to target therapy and measure recovery. We have designed (patent filed), and built a laboratory tested device that combines an IMU with an MMG sensor and demonstrated novel signal processing techniques that reduce problems of vibration artifacts and generates qualitative and quantitative information on mechanical muscle activity and movement. This will be used as the Mk1 device. Patients and therapists have told us that this is what is needed and we will work closely with two NHS Trusts, our patient representatives, therapists and commercial partners to develop, CE mark, validate and evaluate in terms of feasibility and potential cost-saving to the NHS a wireless Mk2 M-MARK for clinical use. We will design software packages for therapists and patients with real-time and off-line analysis; and display sets of user-specific feedback on a computer/tablet device.

Lay abstract: M-MARK will help stroke patients regain arm function by supporting independent home-exercise. It will reduce time spent with therapists and allow patients to have the recommended 45 minutes daily therapy more flexibly. It will diagnose patients problems accurately and more cheaply and practically than using laboratory-based technologies. M-MARK will provide feedback on an iPAD, using either an avatar (a human-like figure that mimics patients movements) or through success playing games. Patients practise movement tasks, such as reaching to pick up a cup. Feedback during and after movements shows whether they have moved and used their muscles correctly, such as reaching by extending their arm rather than leaning forward. The therapists version, with different software and interfaces, will provide important information for clinical decision-making, treatment and progress, making therapy more efficient and effective. Patients and therapists told us that this is what is needed. Stroke survivors leave hospital as soon as possible to receive rehabilitation at home, but about 60% fail to regain useful arm function. Intensive practice leads to better recovery, but re-learning to move more normally is also important and is traditionally guided by therapists, which is expensive. This low-cost wearable device will provide guidance and feedback automatically. It will measure arm movements using movement sensors like those in a mobile phone and muscle activity using a device like a microphone that detects vibration when muscles are active. Together they will describe amount and quality of movement. We have built a prototype and demonstrated that it can generate the information needed. Working with patients and therapists we will develop, validate and feasibility-test a commercial (Mark2) device incorporating user interfaces, wireless connectivity and an easy-to-don garment. We will CE mark it, examine potential cost savings to the NHS and produce a business plan for commercialization and implementation throughout the NHS.

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS
Health categories: STROKE