PFI:BIC - Cyber-Physical Service System for 3D-Printing of Adaptive Custom Orthoses

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This Partnership for Innovation: Building Innovation Capacity (PFI:BIC) project aims to develop a service system for Internet-based design and rapid manufacturing of foot orthoses and ankle-foot orthoses with custom fit and motion sensors. Orthoses are externally applied assistive devices that meet the personal needs of people with disabilities. They are designed to achieve one or more of the following goals: control of biomechanical alignment, correction or accommodation of deformity, and/or protection and support of an injury. Custom-made orthoses provide a better fit for users. They are more comfortable and facilitate more effective treatment. However, the traditional plaster molding fabrication method for custom orthoses requires a long delivery time and multiple visits to the clinic, which are often physically, mentally, and/or financially difficult for users of orthoses and their caregivers. The service system is targeted for the One-Day Visit by facilitating the measurement, design, fabrication, and evaluation of foot orthoses and ankle-foot orthoses all within the same day of the patient's visit to the clinic. The current custom orthoses design also lacks both the adaptability to adjust the stiffness for individual needs and the sensors to measure and record the motion data for clinicians and users. This project plans on creating a cyber-physical service system aimed to fulfill these needs. The projected service system utilizes cloud-based design and 3D-printing, a rapid manufacturing technique for custom orthoses, to enable the One-Day Visit. For this system, the clinician scans the foot and leg of the patient and uploads the geometrical and clinical prescription data to a cloud-based Cyber Design Center, which has the biomechanical models, baseline inertia measurement unit (IMU) sensor data, and a user-in-the-loop framework developed in this project to design the user-adaptive, sensor-embedded custom orthoses. Advanced lightweight, energy-efficient motion sensors measure and record the orthosis motion in the living environment for a week. While recharging the battery of the IMU data logger, the subject's motion data are uploaded to a cloud database and analyzed for evaluation of the gait and orthosis functions for the user. This research connects three key aspects of the fused deposition modeling (FDM) for fabrication of custom orthoses: the measurement of defects using nano-computed tomography, prediction of plastic material properties based on the defect geometry, and FDM process optimization. The ruled-based biomechanical decision-support model that can automatically design the shape of custom foot and ankle-foot orthoses based on user information and clinician prescription is studied for orthosis design practice. The development of a user-based optimization framework with long-term motion data of a user as the input will advance the scientific knowledge of user-in-the-loop design and control of assistive devices. This cyber-physical service system for custom orthoses presents a vision wherein the cloud-based design and 3D-printing technologies can harmonize with healthcare by providing a better service for assistive device users and their caregivers. The efficacy of treatment and the quality-of-life of people with disabilities can be improved by having comfortable and adaptable orthoses delivered in a timely fashion. The lead institution, University of Michigan (Ann Arbor, Michigan), is partnering with Stratasys (Eden Prairie, Minnesota) and Altair (Troy, Michigan) in this project. The University of Michigan offers extensive research innovations in optimizing internal structures for 3D-printed porous structure, novel passive dynamic orthosis design, using motion sensors for gait analysis, and user-in-the-loop design and control. Stratasys, a pioneer and leader in FDM machines and materials, will partner to provide the state-of-the-art FDM technology. Altair has cloud-based product design center expertise, which includes all the associated software, hardware, and security infrastructure. Broader Context partners include Becker Orthopedic (Troy, Michigan); University of Michigan Orthotics and Prosthetics Center (Ann Arbor, Michigan); and VA Ann Arbor Health System (Ann Arbor, Michigan).