Instrumented elbow orthosis

D Morgado, T Suzuki, P Smitham, Catherine Holloway, D Hill
in European Conference of the International Federation for Medical and Biological Engineering (MBEC 2014), Conference paper (text), Dubrovnik, Croatia

Abstract

Although work on exoskeleton technology started as early as in the 1960's, it is mostly recognized and used as devices to aid in the rehabilitation process and for military purposes. The use of wearable and portative exoskeleton technology for functional compensation is less well understood for the upper limbs in comparison with the lower limbs. A review of current upper limb exoskeleton technology suggests that there is limited attention to the interaction between the exoskeleton and the human. In order to control or compensate movement, exoskeletons transfer forces through a physical coupling between the device and the human limb (exoskeleton-human interface). This exoskeleton-human interface is a physical coupling that requires the consideration of optimal and safe force transfer (magnitude, direction and locations) as well as user comfort; considerations that have been overlooked by current exoskeleton technology. Before implementing a highly specialized electronic control system between the user and exoskeleton, it is necessary to design a truly wearable, safe and comfortable mechanical structure. The aims of this study are to modify a commercial elbow orthesis by instrumenting it with a control system and force sensors in order to measure the following parameters: dynamic stiffness and pressure between the orthosis and the human skin. This instrumented orthosis is further controlled by the user through a mouth switch. The instrumented orthosis is employed to monitor forces and stiffness during activities of daily life which involve self-care and domestic life for a fully abled person. Upper limb exoskeleton designers could use this data to fabricate technology that exerts forces that are safe and within what the end user considers comfortable. This modified orthosis will be used in a future study in individuals with spinal cord injury from C5 to C8 levels.