Telerobotic System Treats Bladder Cancer Better

The prototype device, developed by researchers at Vanderbilt University (Nashville, TN, USA) and Columbia University (New York, NY, USA), is designed to be inserted through natural orifices, in this case the urethra. The device is the size and shape of a large Thermos bottle, but the operational head is only 5.5 millimeters in diameter, and consists of a segmented robotic arm which curve through 180 degrees, allowing it to point in every direction, including directly back at the entry point. At the tip is a light source, a fiberscope for observation, an optical fiber laser for cauterization, and forceps for gripping tissue.

Position of the snake-like arm can be controlled with submillimeter precision, and the fiberscope produces a 10,000-pixel image directed to a digital video camera system. Because it is steerable, the instrument is able to provide close-up views of the bladder walls at favorable viewing angles. In the future, the researchers intend to incorporate additional imaging methods for improving the ability to identify tumor boundaries. These will include fluorescence, ultrasound, and infrared (IR) optical coherence tomography (OCT) to augment the surgeon's natural vision.

In addition to these observational methods, the researchers have provided the robotic arm with force-feedback, which allows them to haptically measure the force acting on the tip when it comes into contact with tissue. New algorithms allow the robotics to accurately trace a tumor's edge, based on differential pressure readings derived from the cancerous tissue’s character. The study describing the prototype was published in the April 2013 issue of IEEE Transactions on Biomedical Engineering.

“Surgeons can typically identify the gross visual margin of a tumor within a millimeter, but a robot like this has the potential of doing so with submillimetric precision, and additional technologies may actually be able to distinguish margins at the cellular level,” said study coauthor S. Duke Herrell, PhD, associate professor of urologic surgery and biomedical engineering at Vanderbilt University Medical Center. “The system doesn't take the judgment out of surgeons' hands; it enhances their capabilities and hopefully gives them surgical superpowers.”

Bladder cancer, a significant cause of morbidity and mortality worldwide, presents a unique opportunity for aggressive treatment due to the ease of transurethral accessibility. However, while the location affords advantages, transurethral resection of bladder tumors can pose a difficult challenge for surgeons encumbered by current instrumentation or difficult anatomic tumor locations.

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