Stiffness and alignment of ankle-foot orthoses (AFOs) are essential factors for its optimal function and fit. Improper stiffness and alignment of an AFO may induce joint pain, reduced ambulatory function, and increased medical complications for patients with stroke. As a consequence, the relative quality of AFOs fit determined by its stiffness and alignment is of paramount concern in the daily lives of patients ambulating with an AFO. The objective of the proposed work is to create and demonstrate a novel system for AFOs called the Computerized Orthotic Prescription System (COPS), which assists orthotists to optimize the dynamic function of AFOs for patients with stroke. COPS assists orthotists in tuning the AFO stiffness dynamically and aligning the AFO statically. The concept of the COPS is as follows. It consists of an instrumented insole, a tunable AFO with a magnetro-rheologic fluid brake joint and software. The inclinometer incorporated within the AFO is used to tune alignment to a defined angle statically. The instrumented insole is designed to calculate the external moments acting on the ankle joint while wearing the AFO. The software subsequently analyzes the data sent wirelessly from the insole and gives recommendations to orthotists on its stiffness change dynamically. In this study, we will refine the prototype instrumented insole and incorporate it into the tunable AFO, develop a stiffness prediction algorithm for the software, and clinically test the proof of concept of COPS. Development of the stiffness prediction algorithm will be based on our experience on the previous project: the Computerized Prosthesis Alignment System (Compas). The fuzzy logic algorithm for prediction of improper stiffness will be developed through input of data collected for known stiffness deviations. Finally, proof of concept will involve the investigation of the effectiveness of COPS to detect sub-optimal stiffness conditions and the ability of COPS to indicate appropriate remediation to the orthotist. If successful, COPS will give confidence to both orthotists and patients and significantly reduce time for the iterative process of stiffness and alignment tuning an AFO.
This project will assist and improve the prescription of ankle-foot orthoses (AFOs) for patients with stroke. The technology will objectively guide the orthotists to determine the optimal stiffness and alignment of AFOs to maximize their dynamic function for each individual patient.
|Howell, Adam M; Kobayashi, Toshiki; Chou, Teri Rosenbaum et al. (2012) A laboratory insole for analysis of sensor placement to determine ground reaction force and ankle moment in patients with stroke. Conf Proc IEEE Eng Med Biol Soc 2012:6394-7|