Minimally invasive surgeries require complicated maneuvers, delicate hand-eye coordination, and ideally would incorporate “x-ray vision” to see beyond tool tips and underneath tissue prior to making incisions. The Photoacoustic and Ultrasonic Systems Engineering (PULSE) Lab is pioneering this feature, but not with harmful ionizing x-rays. Instead, we use optical fibers for photoacoustic sensing of major structures – like blood vessels and nerves – that are otherwise hidden from a surgeon’s immediate view. Our goal is to eliminate surgical complications caused by accidental injury to these structures. Photoacoustic imaging utilizes light and sound to make images by transmitting laser pulses that illuminate regions of interest, causing thermal expansion and the generation of sound waves that are detectable with conventional ultrasound transducers.
In this talk, I will describe our novel light delivery systems that attach to surgical tools to deliver light to surgical sites. I will also introduce how we learn from the physics of sound propagation in tissue to develop acoustic beamforming algorithms that improve image quality, using both state-of-the-art deep learning methods and our newly developed spatial coherence theory. These light delivery and acoustic beamforming methods hold promise for robotic tracking tasks, visualization and visual servoing of surgical tool tips, and assessment of relative distances between the surgical tool and nearby critical structures (e.g., major blood vessels and nerves that if injured will cause severe complications, paralysis, or patient death). Impacted surgeries and procedures include neurosurgery, liver surgery, spinal fusion surgery, hysterectomies, and biopsies.