Optical coherence elastography based on inverse compositional Gauss-Newton digital volume correlation with second-order shape function

Abstract

A digital volume correlation (DVC)-based optical coherence elastography (OCE) method with inverse compositional Gauss-Newton (IC-GN) algorithm and second-order shape function is presented in this study. The systematic measurement errors of displacement and strain from our OCE method were less than 0.2 voxel and 4 × 10−4, respectively. Second-order shape function could better match complex deformation and decrease speckle rigidity-induced error. Compared to conventional methods, our OCE method could track a larger strain range up to 0.095 and reduce relative error by 30-50%. This OCE method has the potential to become an effective tool in characterising mechanical properties of biological tissue.

Impact of Speckle Deformability on Digital Imaging Correlation

“…Therefore, a validating experiment using real imaging data was not able to be included in this study. In the future, the deformation fields will be mimicked using our developed optical coherence tomography (OCT)-based mechanical test experiment [29]. Then the ICGN-1 and ICGN-2 based DVC algorithms will be able to be analysed based on the real experimental data.…”

High‐accuracy optical coherence elastography digital volume correlation methods to measure depth regions with low correlation

“…Regardless of the theoretical error model or the DVC method, the first-order displacement shape function is selected to describe the deformation of the specimen in compression tests well. However, when the method is applied to a complex loading or complex deformation of the specimen, it is necessary to use the second-order shape function to describe the complex deformation of the object to reduce the systematic error caused by undermatching [22]. Second, this paper proposes an efficient parallel strategy and provides preliminary time data.…”

“…Meng et al [19] introduced the efficient and high-precision inverse Gaussian Newton DVC algorithm into the OCE method, which enabled the accuracy of displacement measurement and strain calculation to reach 2 μm and 0.003, respectively. Wu et al [22] used the second-order shape function to match the complex deformation and extended the tracking strain range to 0.095 with a relative error reduction of 30%-50%. Zhong et al used a pre-registration technique to eliminate large rigid body translation before DVC calculations and introduced a confidence parameter to guide the searching path in displacement calculation and a confidence-weighted strain calculation method.…”