Shear wave optical coherence elastography with modulation-division multiplexing of sensing probes

Abstract

Optical coherence elastography (OCE) is a powerful biomedical imaging technique that allows for the non-invasive estimation of Young's modulus in samples. In comparison to compressional OCE, shear wave (SW) OCE directly estimates Young's modulus through the measurement of shear wave propagation speed. This approach eliminates the need for absolute calibration between applied force and displacement, making SW OCE a valuable tool for biomedical research. In this study, we propose a method for spectral-domain OCE measurements using multiplexed probes. Our approach involves applying amplitude modulation at different frequencies to the radiation emitted by each multiplexed probe. By observing the variation in amplitude over time, we can identify the different interference components from each probe and estimate their frequencies. This allows for more accurate and precise measurements of Young's modulus. By exciting an acoustic shear wave in a sample and measuring the phase delay between two multiplexed optical coherence tomography (OCT) probes, the elasticity of the sample can be estimated. Compared to traditional SW OCE, the proposed approach with multiplexed sensing probes offers improved repeatability and accuracy, as well as high robustness against positioning errors, especially at high spatial resolutions. The feasibility of this approach is demonstrated by measuring the speed of shear waves in gelatin tissue phantoms with added inhomogeneities and different epidermal tissues.

Speaker

Nikolai A. Ushakov
Peter the Great St.Petersburg Polytechnic University
Russia

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