Feasibility of laparoscopic photoacoustic imaging system based on diffusing side-illumination fibers
26 January 2022 • 1:30 PM - 1:45 PM PST | Room 211 (Level 2 South)
Laparoscopic surgery is commonly used in the abdominal creating minimal trauma to the patient. With the current standard videoscope, visualizing vessels under the tissue is challenging. Photoacoustic (PA) imaging is laser-generated ultrasound imaging that offers vascular mapping. However, most in vivo PA imaging is limited by the lack of depth penetration due to the insufficient illumination in deep tissue caused by the light scattering and the risk of over-irradiation near laser contact tissue. Having a method to bring the signal sensing device closer to the target area is critical for the PA-guided intervention. A miniaturized PA laparoscopic should increase the maneuverability inside the abdominal for better visualization of the operational region. A PA imaging probe mainly consists of optical fibers and an ultrasound (US) transducer. While the US device miniaturization has been investigated, previous works used customized angled-tips fiber for side-illumination to miniaturize the light delivery, requiring multiple fibers or having limited illumination region. Diffusing fiber can illuminate a wider region with fewer fibers than angled-tip side-illumination fibers. This could further minimize the diameter of the entire PA laparoscopic by several millimeters. We propose a PA laparoscopic system imaging with only two diffusing side-illumination fibers while maintaining high image contrast. The phantom study shows the system can image 0.30 mm resolution with a 30 dB signal-to-noise ratio in an optical scattering environment. The result demonstrated the feasibility of delivering sufficient energy with diffusing fiber to miniaturize the dimensions of the PA laparoscopic device.
Worcester Polytechnic Institute (United States)
Shang Gao, born in Nagoya, Japan, is currently a Ph.D. student in Medical FUSION (Frontier Ultrasound Imaging and Robotic Instrumentation) Laboratory at Worcester Polytechnic Institute, USA. He earned his M.S. degree in Robotics Engineering from the same institution in 2020, dual B.Eng. degrees in 2018 in Robotics & Mechatronics System Engineering from Univ. of Detroit Mercy, USA, and Mechanical Engineering from Beijing Univ. of Chemical Technology, China, respectively. His current research interests include medical robotics, photoacoustic imaging, and robot teleoperation.