Researcher(s)
- Pratima Oulkar, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Stephanie Cone, BMEG, University of Delaware
Abstract
The measurement of muscle and tendon forces is essential for better understanding human movement. Conventional techniques are limited by their invasiveness or inherent assumptions, which can affect reliability and clinical applicability. Shear wave tensiometry is a non-invasive technique for estimating tendon force in vivo through a device that applies controlled taps above the tendon while an array of accelerometers measures the speed of resulting shear wave. As tendon tension increases, shear waves travel faster, enabling an estimation of internal tendon force during both static and dynamic activities. This summer, tensiometer devices were built using 3D-printed parts, electronic components, and flexible materials that allow them to conform to the tendon area. Devices were placed on the patellar tendons of three participants. Participants first performed squats to confirm placement and walked on a treadmill. Tendon loading during walking was compared across participants for each device to verify consistent function and confirm device reliability.
To extend this principle, a wearable mechanical stimulator was developed for use in tendon rehabilitation. Tendinopathy is a chronic and painful condition that often does not respond well to exercise-based or other standard therapies that can be uncomfortable and difficult to access. The stimulator delivers localized, mechanical pulses to the tendon with the goal of providing prolonged, low-burden treatment. To build the device, a voice coil actuator was used to generate mechanical stimulation, powered by a battery-operated system. An adjustable pulse generator module was used to control the stimulation frequency, and an amplifier was added to ensure a strong signal output towards the actuator. The components were assembled into a compact layout and secured within a lightweight, adjustable enclosure designed using CAD software and 3D printed to be comfortable during movement. It provides a practical way to apply mechanical stimuli that supports tendon healing and improves function during recovery.