Abstract
Cervical collars are medical devices commonly used to restrict motion of the cervical spine after trauma or surgical intervention. Improvements to the kinematic adjustability of collars and the rigidity of the contact surface between the patient’s body and the collar would result in better restriction of motion while maintaining comfort and fit. This paper reports on the initial design and prototyping of a new design concept for cervical collars consisting of pouches of granular material along the inside of two rings which are of similar geometry to the neck. The rings are connected by six adjustable length struts, analogous to the classical Stewart-Gough platform. Granular jamming is a reversible process in which a bladder containing a granular material, such as coffee grounds, becomes stiff when a vacuum is drawn on it. Thus, the pouches allow for a moldable interface with the neck with adjustable rigidity. The 3D printed rings are designed to accommodate the geometry of individual wearers by flexure hinges approximating a continuously deformable structure. The geometry of the rings was selected by surface modeling of the body geometry followed by extraction of coordinate curves and flattening. The struts provide patient specific adjustments for neck height and variance in head shape.
