3D Strain and Elasticity Measurement of Layered Biomaterials by Optical Coherence Elastography based on Digital Volume Correlation and Virtual Fields Method

Fanchao Meng,Jingbo Wang,Cuiru Sun,Chuanwei Li,Jinlong Chen,Xinya Zhang

doi:10.3390/app9071349

Abstract

The three-dimensional (3D) mechanical property characterization of biological tissues is essential for physiological and pathological studies. A digital volume correlation (DVC) and virtual fields method (VFM) based 3D optical coherence elastography (OCE) method is developed to quantitatively measure the 3D full-field displacements, strains and elastic parameters of layered biomaterials assuming the isotropy and homogeneity of each layer. The integrated noise-insensitive DVC method can obtain the 3D strain tensor with an accuracy of 10%. Automatic segmentation of the layered materials is realized based on the full field strain and strain gradient. With the strain tensor as input, and in combination with the segmented geometry, the Young’s modulus and Poison’s ratio of each layer of a double-layered material and a pork specimen are obtained by the VFM. This study provides a powerful experimental method for the differentiation of various components of heterogeneous biomaterials, and for the measurement of biomechanics.

Highlights

Optical coherence elastography (OCE) uses optical coherence tomography (OCT) as an imaging modality to measure the mechanical properties of biological tissue [1,2]
This study is to develop a digital volume correlation (DVC) and virtual fields method (VFM) based OCE method for the quantitative characterization of mechanical properties of layered biological tissue
The 3D OCE method based on DVC and VFM has been developed in this study

Summary

Introduction

Optical coherence elastography (OCE) uses optical coherence tomography (OCT) as an imaging modality to measure the mechanical properties of biological tissue [1,2]. To extract mechanical information such as strain and elastic modulus from OCT interference signals, phase-based [3,4] and speckle tracking based [5] methods can be used. In 1998 Schmitt first proposed the concept of OCE or OCT elastography [5]. He used a normalized cross-correlation (NCC) speckle tracking method to measure the displacements and strains of gelatin phantoms and tissue specimens including pork meat, and intact skin in two dimesnions (2D). This work demonstrated the feasibility of applying speckle correlation to extract mechanical properties from

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Discussion

Conclusion