Researcher(s)
- Benjamin Bober, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Stephanie Cone, Biomedical Engineering, University of Delaware
Abstract
Shear wave tensiometry is a technique used to assess in vivo tendon loading. Setup of this device remains variable, making it difficult to achieve consistent measurements across operators. This project aimed to redesign the shear wave tensiometer to decrease device attachment time and improve device placement.
The original and new devices are constructed with 3D printed housings for two uniaxial accelerometers and a mechanical actuator held at a set distance by fishing wire. The old device is secured by self-adhesive tape onto the tendon. The new device is secured to the tendon using a compression sleeve with Velcro and uses 3D printed housings optimized for the new design.
The new device was validated based on efficiency, efficacy and measurement accuracy to the original design. Researchers randomly applied both devices to the Achilles tendon of one person. Time to place each device and ease of use (one (easy) – seven (difficult)) was recorded for each operator. Participant comfort was recorded for each device on a scale from one (comfortable) – seven (uncomfortable). Participants completed two gait trials at 3.0 MPH while shear wave speeds were confirmed. Data was analyzed using statistical parametric mapping, Bland-Altman tests, and paired tests.
Measurements from the new and original device were not different, indicating that devices perform similarly during dynamic testing. A Bland-Altman plot revealed potential systematic bias with a mean difference of -9.6386, suggesting more subjects should be tested to further validate the device. The new device (226 seconds) took significantly longer than the original device (156.8 seconds) to confirm placement (p = 0.006), but the new device (1.8) was easier to use than the original device (3.0) (p = 0.108). Lastly, participants found the new device (1.4), more comfortable than the original device (4.0) (p = 0.012).