Force Distribution Measurement System Research Articles

SONIGait: a wireless instrumented insole device for real-time sonification of gait

The treatment of gait disorders and impairments are major challenges in physical therapy. The broad and fast development in low-cost, miniaturized, and wireless sensing technologies supports the development of embedded and unobtrusive systems for robust gait-related data acquisition and analysis. Next to their applications as portable and low-cost diagnostic tools, such systems are also capable of use as feedback devices for retraining gait. The approach described within this article applies movement-based sonification of gait to foster motor learning. This article aims at presenting and evaluating a prototype of a pair of instrumented insoles for real-time sonification of gait (SONIGait) and to assess its immediate effects on spatio-temporal gait parameters. For this purpose, a convenience sample of six healthy males (age $$35\pm 5~\hbox {years}$$ , height $$178\pm 4~\hbox {cm}$$ , mass $$78\pm 12~\hbox {kg}$$ ) and six healthy females (age 38 ± 7 years, height $$166\pm 5~\hbox {cm}$$ , mass: $$63\pm 8~\hbox {kg}$$ ) was recruited. They walked at a self-selected walking speed across a force distribution measurement system (FDM) to quantify spatio-temporal gait parameters during walking without and with five different types of sonification. The primary results from this pilot study revealed that participants exhibited decreased cadence (p < 0.01) and differences in gait velocity (p < 0.05) when walking with sonification. Results suggest that sonification has an effect on gait parameters, however further investigation and development is needed to understand its role as a tool for gait rehabilitation.

A Development of Force Distribution Measurement System with High Resolution for Total Knee Arthroplasty

Soft tissue or ligament balancing in total knee arthroplasty is important for ensuring knee joint stability. Correct balancing and appropriate alignment of ligaments extend prosthesis life by preventing unnecessary force fromacting on the prosthesis during routine activities. The current implementation of total knee arthroplasty relies heavily on the subjective “feel” of the surgeon for correct prosthesis implantation onto tibiofemoral components. We developed a force distribution sensing systemto provide quantitative information to surgeons during ligament balancing. The measurement system consists of two main components: two force sensors embedded in trial insert for each condyle and signal acquisition for data processing and force visualization. Sensors were designed and developed using pressure-sensitive conductive rubber that measures changes in resistance in the event of deformation caused by external force. Corresponding voltage measured by circuits is transmitted via an RF transceiver to a computer and visualized as color gradient. Current sensors could measure maximum force of 196.13 N (20 kgf). Results from calibration and experiments on a plastic trial prosthesis indicated that the device has good potential for providing appropriate force distribution information on the knee during total knee arthroplasty procedure.