ZEUS robot at once involved in lawsuit and in clinical surgery primeur

Pittsburgh 09 April 2001The University of Pittsburgh is the first centre in the United States to use Computer Motion's ZEUS Robotic Surgical System during a beating heart cardiac bypass operation. Surgeons manipulated the three-armed robot during the most important part of the operation, when the artery being applied as the bypass graft is connected to the heart's main coronary artery. At the same time, Computer Motion Inc. was jointly sued by its competitor, Intuitive Surgical Inc., an expert in precision surgical robotics, and IBM in the U.S. District Court for the District of Delaware.


The Intuitive and IBM complaint alleges that by continuing to make, use, sell, and offer for sale its AESOP and ZEUS voice-controlled products, Computer Motion wilfully infringes U.S. Patent No. 6,201,984. Meanwhile, a 63-year-old male patient underwent multi-vessel off-pump coronary artery bypass surgery at the University of Pittsburgh Medical Center (UPMC) Presbyterian Hospital on April 5 as part of a national, multi-centre trial seeking to evaluate whether the ZEUS robotic system can be helpful to surgeons and be safely used for the surgical connection of the left internal mammary artery graft to the left anterior descending artery.

The University of Pittsburgh is one of 12 centres in the research study and the first U.S. centre to apply the ZEUS in a beating heart bypass operation. The robot had been used in 32 patients at three centres as part of a phase one trial, but in all of these cases, the operation involved the support of a heart-lung machine while surgeons operated on a stopped heart.

Marco A. Zenati, M.D., an assistant professor of surgery and the principal investigator at the Pittsburgh site, operated the robot while seated at a console about 10 feet from the patient. One arm of the robot, responding to his voice commands, positioned the endoscope, an instrument with a tiny camera that magnifies the operative site up to 10 to 15 times. While viewing the magnified image of the heart and vessels on a high-resolution monitor, Dr. Zenati controlled the action of surgical instruments attached to the two other robotic arms by operating handles that resemble conventional surgical instruments, in much the way joysticks are used to control the action of a video game.

"ZEUS is designed to give a surgeon greater precision while performing micro-surgical tasks and to be able to use it during a beating heart operation is extremely significant. Essentially, it may allow surgeons to perform superhuman tasks, because the robot overcomes our dexterity and precision limitations", commented Dr. Zenati. The surgeon's hand movements are scaled. For instance, one inch of movement by the surgeon results in a one fourth inch movement by the robotic surgical instruments. Hand tremor is filtered by the computer and translated via the robotic arms into precise micro-movements at the operative site.

According to Computer Motion Inc., the Santa Barbara-based company that developed ZEUS, the possible benefits of using ZEUS in a closed-chest heart bypass surgery include less patient pain and trauma, quicker recovery times and reduced health care costs. The reason is that robotics and computers provide enhanced dexterity, steady visualisation, and improved ergonomics for the surgeon. The reduced trauma to the patient, from a minimal incision and the avoidance of the heart-lung machine, can translate into reduced costs.

"The use of robotics for cardiac surgery is a very exciting development for the field. Medical experts anticipate that the future will soon see all cardiac procedures employing such technology, and surgery will become less and less invasive for the patient", commented Bartley P. Griffith, M.D., Henry T. Bahnson professor of surgery and chief, division of cardio-thoracic surgery at the University of Pittsburgh School of Medicine. Dr. Griffith is a co-investigator of the study and assisted Dr. Zenati during the operation. Dr. Zenati also was assisted by Larry Shears, M.D.

On March 13, 2001, U.S. Patent No. 6,201,984 was issued to IBM and is exclusively licensed to Intuitive under the terms of Intuitive's 1997 License Agreement with IBM. This patent concerns various aspects of controlling movement of surgical instruments with voice commands, and predates by several years Computer Motion's development of voice-controlled surgical robots. Because this company's voice-controlled HERMES product interfaces with the AESOP and ZEUS products, HERMES is also implicated in the patent infringement complaint. More news on the ongoing conflict between Computer Motion and Intuitive is available in the VMW July 2000 article Computer Motion to start patent infringement war on medical robotics against Intuitive Surgical.

Leslie Versweyveld

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