Robotic Prosthesis Alignment System: RoboPAL

Period of Performance: 08/01/2007 - 09/29/2007


Phase 1 SBIR

Recipient Firm

Cyma Corporation
Mountlake Terrace, WA 98043
Principal Investigator


DESCRIPTION (provided by applicant): Positioning of the socket relative to the foot of a lower limb prosthesis is critical to comfort, function, and health of the residual limb and intact musculoskeletal system. Achieving proper alignment is currently a time- consuming and imprecise art that requires considerable skill and effort on the part of the prosthetist, and permits no direct control by the patient. The proposed project will significantly advance the alignment process. The objective of the proposed work is to create a Robotic Prosthetic Alignment system (RoboPAL) that enables the alignment of lower limb prostheses to be rapidly adjusted by robotic control. The system will allow both the prosthetist and the patient to specify alignment changes via a hand-held control unit communicating wirelessly with an actuator unit integrated with standard modular components. The technology will permit the prosthetist to concentrate on "the big picture" (i.e. eliminate time on the floor with wrenches in hand), and will enable the patient to participate more fully by directly controlling adjustments. In addition, the system will be capable of accepting input from the Computerized Prosthetic Alignment System (ComPAS), a separate technology that measures loads transmitted through the prosthesis, calculates magnitude and direction of misalignment, and outputs direction and magnitude of advised alignment modifications. When RoboPAL and ComPAS are used together, the result will be an auto-aligning limb. The system also opens the door for telemedicine applications - adjustments directly controlled by experienced practitioners observing patients via web-streamed video in areas without adequate prosthetic care. In the proposed work, we will design and build the prototype system, evaluate performance and feasibility with human subjects, and review the results with the subjects and colleagues in clinical prosthetics. This project will advance the important process of aligning the components of lower limb prostheses. The technology will allow the prosthetist to adjust the alignment quickly, easily, and in a more well-controlled manner than is currently possible. It will also allow the patient to directly participate in aligning the limb, and will make it possible for alignment to be accomplished remotely through a telemedicine paradigm.