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Biological Tissue as a Strain Gauge

ID: 2012-004 Using the inherent electrical characteristics of soft tissue.

Principal Investigator: Anton Bowden

Soft tissue exhibits inherent electrical characteristics that repeatedly vary in response to mechanical strain. The invention utilizes these characteristics in a manner that allows for tracking of soft tissue strain using electrode arrays.

The research that lead to this invention was exploring the possibility that the inherent electrical properties of a tendon might allow it to act as its own strain gauge. Tendon has been shown to exhibit piezoelectric effects as well as streaming potentials when subjected to a mechanical stress. To assess the feasibility of using these properties to repeatably measure in situ strain, bovine Achilles tendon test specimens were connected in series with a control resistor in a direct current circuit. Longitudinal (along the collagen fiber direction) and transverse test specimens were subjected to sinusoidal tension while electrical resistance data for the specimens was collected. Change in resistance per unit strain and gauge factors revealed a repeatable and significantly different correlation between resistance and strain for the longitudinal and transverse specimens (p <.001). Others have reported piezoelectric mechanisms and streaming potential mechanisms in hydrated collagen, however the present work is unique in presenting an accurate and repeatable model of an isotropic tendon behavior that could be used to develop an in situ strain sensor.

Advantages of the invention include:
- Cost effective
- Highly-repeatable
- Lack of systematic error induced by application of external devices or markers

About the Market:
The invention would be of interest to athletic apparel manufacturers, medical device manufacturers, athletic programs/exercise science programs, biomechanics equipment manufacturers, biomechanics research programs, and surgeons.
For more information, contact Mike Alder (801-422-3049)

Links and Resources

  1. Inventor Webpage - Anton Bowden
  2. Inventor Webpage - David Fullwood