Design of a dynamic and adaptive head support

For people with severe muscle weakness or paresis in the trunk and neck muscles, adequate head support is required. Although several assistive devices exist that can support a person’s head position, there is an absence of devices that are capable to support head movements in a natural and safe way. The large individual variation between users requires an individual match between user and assistive device. From initial market research it can be concluded that there is a need for assistive devices that provide dynamic adjustability by combining changes in position of the trunk and head with continuous stabilization. Within the project, the main objectives were to characterize this need for support, and to develop a first proof-of-concept of a dynamic and adaptive head support.

Position control was implemented on an actuated head support system with four degrees of freedom (e.g. three translations and one rotation in flexion-extension), using a six degree-of-freedom force sensor as a joystick interface. For the current control method, manipulation of the joystick results in the head support following part of the natural flexion-extension motion of the head, coupling multiple degrees of freedom of the actuated system. Additionally, the system can autonomously adapt the head support position according to the back seat angle of the electric wheelchair, to compensate for changes in posture relative to the wheelchair seat caused by changing seat settings.

Initial functional testing shows that the current prototype matches the majority of the requirements set in the design phase. Compared to current solutions, the presented system can steer the head support position in 3D in a more efficient and natural way. Therefore, it can be concluded that the redesigned system is a promising first step in the development of a new generation of dynamic and adaptive head supports that are intelligent enough to autonomously personalize their behavior to the user.