Abstract
In blood vessel imaging using photoacoustic effect, ultrasonic signals which are induced by a laser are commonly detected by conventional contacting transducers. Replacing contacting transducers with laser-ultarsonic measurement using laser interferometer, complete non-contact biological tissue imaging would be realized. Non-contact measurement technique would enhance the applicability of ultrasonic measurement. Authors have developed non-contacting photoacoustic imaging technique using Fabry-Perot interferometer. As a generation laser and a detection laser, Nd:YAG laser (2nd harmonic wavelength: 532 nm) and Nd:YAG laser (fundamental wavelength: 1064 nm) were adapted respectively. To improve the sensitivity of detection, 3 dimensional frequency-domain synthetic aperture focusing technique was developed. For the verification, chicken tender and small-bore tubes with an inner diameter 0.1 mm filling with red ink solution were used as a biological tissue and artificial blood vessels respectively. Using non-contact measurement technique, artificial blood vessels which installed under chicken tender with 6 mm thickness were clearly observed.
