Piezoelectrical Micro-Tapper based Three-Dimensional Optical Coherence Elastography for In Vivo Dermatology Applications

In dermatology, alterations in tissue mechanical properties can indicate pathological status, aiding in early diagnosis, localization, and monitoring of skin conditions. Techniques such as elastography are crucial for evaluating these changes. Optical Coherence Elastography (OCE) is an extended function of Optical Coherence Tomography (OCT), offering high-resolution, and non-invasive measurements of tissue mechanical properties. High-resolution three-dimensional (3D) OCE can provide several benefits, including volumetric biomechanical distributions, enhancing comprehensive analysis and quantification. This study was conducted to develop a 3D OCE technology utilizing a piezoelectrical micro-tapper. A miniature co-fired piezoelectrical actuator was employed to provide precise, rapid vibrations at the micrometer scale. A 3D-printed micro-tapper tip, attached to the actuator's work plane, made minimal contact with the tissue surface. The actuator induced mechanical waves, functioning as a linear wave source. These waves propagated within the superficial layers of the tissue and were captured by the OCT system. A benign skin lesion was scanned to demonstrate the functionality of the 3D OCE system. Tissue elasticity was calculated based on the relationship with the group velocity of mechanical waves. Volumetric data on tissue elasticity were processed using the averaging projection method to generate the en face projection of elasticity. A region of high elasticity, with an average value of 261.43 kPa, was identified, contrasting with the full field of view average of 124.82 kPa. This study highlights the potential of 3D OCE for advanced tissue characterization, which could significantly enhance diagnostic accuracy in dermatology and related medical fields. The integration of these technologies provides a comprehensive tool for assessing tissue stiffness and delineating lesions. Future research should aim to validate these results through further studies on repeatability and accuracy to confirm the clinical applicability of this approach. This research lays the foundation for the potential widespread clinical use of 3D OCE across various medical applications.