Orthosis Design System for Malformed Ears Based on Spline Approximation

Abstract

Malformed ears of neonates can be effectively treated by employing an orthosis of suitable shape. Currently, we use orthoses made of nitinol shape memory alloy wire and have developed a computer-assisted design system to manufacture the orthosis. Using this method, extracted contours of the helix and auriculotemporal sulcus are approximated to spline, and orthosis shape can be designed by moving the control points of spline with reference to control points of the target auricular shape. The system also functions to evaluate the contact force between the orthosis and auricle. Using this system, orthoses were designed and manufactured for 16 patients with malformed ears. Treatment was more effective in cases where it was necessary to extend the helix.

Shape Memory Actuators for Medical Rehabilitation and Neuroscience

“…Static orthoses are often used to impart these treatments and may be as rigid as castings or partially compliant. Many authors imagined the use of SMA in orthotics as passive components that apply static corrective forces [20][21][22][23][24][25][26][27][28][29][30]. In these applications SMA are mostly employed for their pseudoelastic properties, even though some designs are also based on SME.…”

“…They also showed possible advantages of this type of devices for correcting equinus gait [25]. In [26], pseudoelastic NiTi was utilised to remodel deformed auricles. Though not strictly correlated to the main subject of Neuromuscular Rehabilitation, this paper presents an approach in which the anatomic and biomechanical constraints are integrated in the design procedure.…”