Kai Zhang, an associate professor at Worcester Polytechnic Institute, recently presented his work on integrating photoacoustic (PA) imaging into robot-assisted surgeries at the 190th Meeting of the Acoustical Society of America.
The innovation addresses the challenges surgeons face when relying on visual cues and experience to avoid hidden hazards, such as nerves or blood vessels often concealed beneath tissue and detectable only with advanced imaging techniques.
Robot-assisted laparoscopic surgeries traditionally involve a laparoscope inserted through a small incision.
Smaller incisions mean reduced pain and shorter recovery times for patients, and robotic assistance provides greater control and precision for surgeons.
Unfortunately, the risk of damaging anatomical structures beneath the surface remains.
Zhang said: ‘Accidentally severing a hidden blood vessel during robot-assisted laparoscopy occurred in 1-2% of cases, depending on the procedure. Furthermore, such incidents can result in a range of complications, including haemorrhage, paralysis, and, in the worst cases, fatal outcomes.’
One emerging solution is PA imaging. This technique directs lasers deep into the tissue, where they are absorbed and produce sound waves. These sound waves can be detected by ultrasensitive microphones and used to pinpoint subsurface structures such as blood vessels and nerve bundles.
Zhang added: ‘This capability enables visualisation of embedded anatomical structures and their depth locations, which is highly valuable for surgical planning and intraoperative monitoring.’
Zhang incorporated PA imaging into a laparoscopic surgery workflow to guide surgeons during operations.
He analysed data from the PA probe and used it to create 3D representations of neurovascular bundles, clusters of nerves and blood vessels that surgeons desperately want to avoid.
These representations were then overlaid onto video from the laparoscopic camera, providing a real-time augmented-reality video feed.
Zhang tested this technique during radical prostatectomies, but PA imaging has applications beyond this one surgery.
Zhang said: ‘We anticipate that this imaging instrumentation will be readily translatable to not only other laparoscopic procedures but also other image-guided procedures.’
