Approaching the Analysis of the Mechanical Properties of Human Achilles Tendon

Abstract

Abstract The literature shows there is no validated procedure to measure the tensile properties in different regions along the length of human tendons. The slippery surfaces and non-homogeneous properties of tendons reduce the probability of success when using traditional methods. So, there is a need to implement an experimental technique that ensures accurate measurement of the mechanical properties of human tissue. The development of new technologies allows us to face problems with new approaches. Computer vision is a trending topic in the development of new technology, one of its branches is digital image correlation (DIC). DIC is a non-contact technique used for tracking pixels along a group of sequential images and, when combined with tensile testing, can be used to track sample deformation and strain at discrete points in space. This work develops a technique that analyzes bovine tendons using digital image correlation and custom-designed 3D printed clamps. The advantage of DIC is that it analyzes the deformation of the tendon throughout the complete sample, allowing us to quantify the mechanical properties in different regions within the tendon. First, a 3D printed clamp is designed considering the challenges of gripping soft tissue. The clamp prevents damage to the tissue during testing. A random speckle pattern is created on the surface of a roller using open CAD software named OpenSCAD. The bovine tendons are painted with the roller and tested in a uniaxial load frame. These results can be used in the future to repeat this technique with human Achilles tendons to quantify the tensile properties of the tendon and aid in the design and material selection of prosthetic tendons for people suffering from injury or disease.