Adaptive arm orthotics for children with Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is caused by mutations of the dystrophin gene located on the X chromosome. This leads to an absence of (or a defect in) the dystrophin protein, which normally provides connection of muscle fibres to the extracellular matrix. DMD affects approximately 1 in every 3500 live male births and it is characterized by progressive muscle degeneration. Most patients are diagnosed at an age of approximately 5 years, when their physical ability diverges markedly from that of their peers. They are often unable to run and jump due to proximal muscle weakness. Since muscle strength deteriorates, boys require use of a wheelchair before their teens. DMD has a predictable nature of complications. Muscles in the legs are first affected, leading to loss of independent ambulation by the age of 13, followed by muscles of the upper extremities. There is a strong decrease of arm function between the age of 10 and 16, although function of the hand remains relatively good. Eventually the heart and respiratory muscles will fail. Until several years ago, DMD resulted in life threatening situations around the age of 20. Corticosteroid, respiratory, cardiac, orthopaedic, and rehabilitative interventions have not only led to improvements in function, quality of life and health, but also an extended live expectancy. Children who are diagnosed today, have a life expectancy into the fourth decade. On account of the increased lifespan, maintaining a proper arm and hand function is very important to increase independency.
From user surveys, there is indicated that it is important that any device that acts as an orthosis should integrate well with the social aspects of activities, such as eating (Stanger, 1994). Preference was to have an body bound orthotic system rather than an external robotic assistive device (Rahman et al., 2000). The stigmatizing effect of assistive devices is indicated as an important reason for not using such devices. From clinical point of view, it is important to continue using the own muscles to move the arms, since disuse will invoke formation of contractures (Jansen, 2010). Goal of this project is to perform a research which will result in the development of an orthotic device which provides adaptive support during various stages of DMD.
To realize the stated objective, it is necessary to get further comprehension of the following principles:
- How can the arm function of a DMD patient be supported with a minimal construction, that is least stigmatizing and stimulates the use of remaining muscle functionality maximally? The support may contain both passive as active components. This will result in the design of an active arm orthosis which provides adaptive support. Innovative aspects are adaptive way of support and wearability.
- How can this device be controlled intuitively in a safe way? The control may be adaptive in that it learns which movements are performed on a regular basis and may require gradually increased support. This will result in design of an intuitive control interface for the orthosis. Innovative aspect are possibilities to explore intention detection and use of learning elements for the control system.
- How can we adequately quantify the functional needs and capacities of any individual DMD patient in each stage of the disease and what is the clinical performance of the newly developed supports? Innovative aspects are the identification of the effect of the new orthosis during the various stadia of DMD.
Other faculties at the University of Twente
- Prof.dr.ir. Peter Veltink (Biomedical signals and systems, EWI)
- Prof.dr. Ir. Just Herder (Mechanical Automation and Mechatronics, CTW / TUDelft)
- Prof. Dr. Ir. Ruud Verdaasdonk (Physics & Medical Technology, VUmc)
- Ing. Micha Paalman (Physics & Medical Technology, VUmc)
- Dr. Imelda de Groot (Rehabilitation Medicine, Radboud University Nijmegen)
- Dr.ir. Jaap Harlaar (Movement Sciences, VUmc)
- Focal Meditech
United Parent Project Muscular Dystrophy