Design of Continuously-Adjustable Light-Scanning Handheld Probe for Photoacoustic Imaging

To form various images at multiple locations for achieving bright- and dark-illumination fields transformation and registration-free image fusion, we proposed a continuously-adjustable light-scanning handheld probe with overall size of 60 × 45 × 80 mm ³ for photoacoustic imaging (PAI). It has a significant advantage for image acquisition under different illumination schemes using motor driving. Specifically, a light adjustment unit was designed to produce light spots, which is more compatible with ultrasonic transducer detection region. Afterwards, multiple PA images revealing diverse features with different optical illumination regions were acquired. Consequently, the fused image was obtained with higher SNR and fidelity than respective PA image. Furthermore, both phantom and ex-vivo experiments were conducted to evaluate imaging performance of the developed probe. Experimental results show that SNR of the fused PA image improves by 36.06% in agar-milk phantom and 44.69% in ex-vivo chicken breast, respectively. Therefore, the proposed PAI handheld probe can achieve our goals well; the registration-free image fusion achieved by adaptive scanning strategy can perform better and demonstrate comprehensive features of the same imaging target.