Abstract
In recent years, regenerative medicine has been being developed due to the improvement of tissue engineering, e.g. autologous regenerative tissue by three-dimensional culture. In this study, Ultrasound-assisted Doppler Velocigraphy (UA-OCDV) is constructed to measure the mechanical properties of regenerated tissues, tomographically, non-contactly and non-invasively at the micrometer resolution. This is based on Doppler OCT, which can visualize Doppler velocity inside tissue by applying phase analysis to low coherence interference signals. Furthermore, an ultrasonic transducer is introduced into Doppler OCT as a non-contact loading device of periodical acoustic radiation pressure. UA-OCDV was experimentally applied to agar-embedded non-woven fabrics as a sample. As a result, UA-OCDV was able to provide the tomographic visualization of Doppler velocity and vibration phase, caused by the acoustic radiation pressure. The propagation of shear wave was visualized according to the spatio-temporal fluctuation of Doppler velocity. The propagation phase, associated with tissue elasticity, was observed to delay from the focal point of radiation pressure to the fixed sample edge. In conclusions, it was suggested that UA-OCDV had a potential of diagnosing the mechanical properties of regenerative tissue non-contactly and non-invasively.
