With better surgical outcomes, quicker recovery times, decreased postoperative pain, and reduced scarring at the surgical site, the application of minimally invasive surgery (MIS) has gained a lot of prominence in the last 30 years. This change in surgical practice has taken away the ability of a surgeon to palpate for the presence of a blood vessel as would occur in an open procedure. They instead must rely on a laparoscopic video camera feed that unfortunately cannot detect the presence of a blood vessel hidden beneath tissue. In certain scenarios, a surgeon can accidentally cut a blood vessel, which can lead to severe, even fatal, complications. Here, we show that by adding a near-infrared LED and a photodiode onto the opposing jaws of laparoscopic graspers, blood vessels buried under tissue can be detected. We show the results of Monte Carlo simulations to support our theory that the blood vessels ranging from 3 to 6 mm buried under up to 1 cm of tissue can be detected and quantified. This technology could be added to already existing laparoscopic tools that have limited surface areas on the jaws to assist surgeons during MIS procedures.
Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.