Use of Digital Image Correlation Method to Measure Bio-Tissue Deformation

Abstract

Traditionally, strain gauge, extensometer, and reflection tracking markers have been used to measure the deformation of materials under loading. However, the anisotropy and inhomogeneity of most biological materials restricted the accessibility of the real strain field. Compared to the video extensometer, digital image correlation has the advantage of providing full-field displacement as well as strain information. In this study, a digital image correlation method (DIC) measurement system was employed for chicken breast bio-tissue deformation measurement. To increase the contrast for better correlation, a mixture of ground black pepper and white sesame was sprayed on the surface of samples. The first step was to correct the distorted image caused by the lens using the inverse distorted calibration method and then the influence of subset size and correlation criteria, sum of squared differences (SSD), and zero-normalized sum of squared differences (ZNSSD) were investigated experimentally for accurate measurement. Test results of the sample was translated along the horizontal direction from 0 mm to 3 mm, with an increment of 0.1 mm and the measurement result was compared, and the displacement set on the translation stage. The result shows that the error is less than 3%, and accurate measurement can be achieved with proper surface preparation, subset size, correlation criterion, and image correction. Detailed examination of the strain values show that the strain εx is proportional to the displacement of crosshead, but the strain εy indicates the viscoelastic behavior of tested bio-tissue. In addition, the tested bio-tissue’s linear birefringence extracted by a Mueller matrix polarimetry is for comparison and is in good agreement. As noted above, the integration of the optical parameter measurement system and the digital image correlation method is proposed in this paper to analyze the relationship between the strain changes and optical parameters of biological tissue, and thus the relative optic-stress coefficient can be significantly characterized if Young's modulus of biological tissue is known.

Mechanical Properties and Residual Stress Measurement of TiN/Ti Duplex Coating Using HiPIMS TiN on Cold Spray Ti

“…In this study, β, ϕ, and ∅ were assumed 0 • , 45 • , and 90 • . The strain ε y , γ xy , and ε y are taken by DIC analysis [15,28,29]. The stress can be calculated for a thin film by Equations ( 4) and ( 5):…”

“…In this study, the area was selected in the center of core Figure 7 of 81 × 81 pixels in size. In this case, the second-order fitting method was applied to the full-field displacement by using Matlab (2009, Natick, MA, USA) according to the research [15,28,29]. The SEM image drift, spatial distortion, and magnification variations throughout the calibration protocol refer to our previous study [28].…”

“…The resulting depth-strain release of the 2p and 8p samples also had the same line profile as Figure 12. The ε x , γ xy , and ε y were depth-strain distribution values obtained at different milling depths after measuring surface strain by DIC analysis [15,28,29]. The depth-strain distribution data were calculated with a 50 nm depth step.…”

An Acoustic Device for Ultra High-Speed Quantification of Cell Strain During Cell–Microbubble Interaction

“…The experimental approach adopted in the present study was informed by the imaging methodology used by Seghir and Pierron . This method supported the use of digital image correlation (DIC), an experimental mechanics technique used to resolve high strain rate deformations in materials, which has also been applied in some biological studies although at lower imaging frequencies. , Overall, the design criteria for the developed apparatus included the need to support cell culture within a fluid chamber that could allow for the microbubble interaction with cells. In addition, the device had to support a reliable and tunable acoustic field that replicated interaction dynamics similar to those in therapeutic and clinical studies.…”

Mechanical Property Test of Grass Carp Skin Material Based on the Digital Image Correlation Method

“…Alice [ 8 ] used DIC to measure the elastic modulus of skeletal tissue and verified the related results of DIC by four-extensometer technique. Chen Y F [ 17 ] combined an optical parameter measurement system with DIC to analyze the relationship between biological tissue strain changes and optical parameters. Thus, when the Young’s modulus of biological tissue is known, the relative optical parameters such as stress factor can be characterized.…”