Robotics in the Operating Room

"Intuitive Surgical has developed a robot for performing surgery, and it offers a less-invasive approach with better clinical results and shorter recovery times.

Imagine peering through a viewfinder, locating a specific target, and then making movements with your fingertips to produce a change in that target. The latest in video games? Hardly! Meet one of the latest surgical assistants: a robot, in particular, the da Vinci robot developed by Intuitive Surgical.

While the idea of robotic systems in the operating room may seem new, they have actually been in use since 1992. Introduced in 1998, the da Vinci consists of a surgeon console, a separate operating table over which the three- or four-armed robot is suspended, and a 3-D vision system. The robot combines the latest in computer and robotic technology to revolutionize the performance of minimally-invasive surgeries (MIS).

The Food and Drug Administration has cleared its use in MIS, including abdominal, cardiac, and gynecological procedures. Currently, it ranks as the only laparoscopic robotic system approved in the U.S.

The brainchild of Dr. Frederic Moll and Robert Younge, an electrical engineer, Intuitive Surgical was formed in 1995 after a third individual, Dr. John Freund, brought the two together. The company’s founders initially used technologies from SRI International, formerly Stanford Research Institute.

Since then, Intuitive has joined with several other prominent organizations to advance robotic research and development. Among these are IBM, the Massachusetts Institute of Technology, Olympus Optical, Johnson & Johnson, and Ethicon Endo-Surgery. Intuitive employs some 250 people at its Sunnyvale, California site, including electrical, mechanical, and computer engineers.

Mike Ikeda is one of them. A mechanical engineer at Intuitive since its conception in 1996, he designs components on the da Vinci system, including the robotic arms and master manipulator (where the surgeon places his fingers to move the robotic arms). He is currently in procedure development, where he works with cardiac surgeons to make efficient use of the robot in coronary artery bypass, mitral valve, and other thoracic procedures. "It’s important to know what surgeons do, so we know what their challenges are," Ikeda says. That philosophy has translated into success for Intuitive.

The founders’ main goal was to develop a system to address the shortfalls of traditional laparoscopic surgery. A laparoscope is a slender, tubular endoscope inserted through an incision in the abdominal wall to examine or perform minor surgery within the abdominal or pelvic cavities. A laparoscope includes surgical instruments manipulated by the surgeon and an optical device using fiber optics to allow the surgeon to see what they’re doing. Laparoscopic surgery, also known as minimally invasive surgery, represented a major breakthrough in surgical techniques. However, the shortfalls include extended operating times, significant blood loss, longer hospitalizations, and protracted recoveries.

The first da Vinci robotic system was sold to a hospital in Germany. Ikeda was sent to instruct surgeons on how to use the system properly and eventually spent about eight months there. While it’s challenging at times to work with surgeons in trying to accommodate their needs in the operating room, "it gets easier," Ikeda says.

When used for urological surgeries such as prostate removal, several one-centimeter incisions called ports are used in the da Vinci surgical procedure; by contrast, traditional (also known as radical) prostatectomies require a sizable incision in the patient’s abdomen. Another drawback to the traditional prostatectomy is the possibility of nerve damage, which can cause incontinence and impotence. The da Vinci robot’s technical features ensure maximum surgeon precision, due to 3-D visualization as well as enhanced surgeon dexterity, precision, and control.

The da Vinci robot consists of four main parts. The first is a cluster of three articulated robotic arms, each with seven degrees of freedom. These arms can carry microinstruments commonly used in surgery such as scissors, clamps, and scalpels. Each arm can position its end effecter (the surgical instrument it carries) anywhere in three-dimensional space and rotate it into any orientation the surgeon requires. The seventh degree of freedom is the capability to move the entire arm anywhere up or down the operating table’s length.

A second important aspect of the robot is its vision system, which enables the surgeon to see precisely what they’re doing in the operation. This is especially important when operating close to vital organs or major blood vessels. The fourth robotic arm carries a stereo endoscope, an optical device with two side-by-side lenses separated by a small distance, affording stereo vision and depth perception.

The da Vinci’s vision system relies heavily on fiber optics. Used extensively in medical imaging, fiber-optic lines consist of strands of optically pure glass as thin as a human hair that carry digital information in the form of light signals over long distances. Fiber optic cables enable more information to be transmitted than traditional electrical wires, and they offer immunity to electromagnetic interference from nearby fluorescent lights, monitors, motors, and antennas.

The third main component is a group of hand and foot controls that enable the robot to be teleoperated. The surgeon moves the controls to shift the robotic arms, manipulate the microinstruments, and position the endoscope to perform the operation. While operating the controls, the surgeon monitors his or her movements by looking into a console with a precision graphics display showing the view seen by the endoscope.

A fourth important part of da Vinci is a set of sophisticated control and image processing algorithms to enhance the surgeon’s accuracy in performing the operation. One of these involves a controller to enable the surgeon to place the instruments precisely where they command.

An adaptive disturbance rejection scheme cancels the surgeon’s natural hand tremors and enables greater accuracy in the placement of the microinstruments, with less danger to neighboring tissue and less blood loss. Disturbance rejection and its close relative, noise cancellation, have found many applications, from canceling noise in telephone lines to rejecting unwanted sounds in audio headphones. This same technology is used by da Vinci via computer algorithm and is invisible to the surgeon in that it needs no input or attention from them.

A major application of the da Vinci robot has turned out to be removing prostates to cure prostate cancer in men. At Norton Hospital in Louisville, Kentucky, surgical nurse Becky Campbell says urologists have been performing prostate removals with the da Vinci at a rate of about two per week in recent months. She and colleague Diana Wetterer take approximately 45 minutes to set up the robot for surgery; they wheel the system into an adjacent, larger operating room, retrieve and sterilize the microinstruments, and place them into the robotic arms. Depending on the nature of the operation, two or three of the robot’s arms are actually used; the fourth arm is the endoscope inserted into the patient’s body for visualization purposes.

"Because of the learning curve involved, we are getting faster in setting up the robot for use, as are the surgeons during prostatectomies," Wetterer says. Typically, there are two surgeons in the operating room, one at the console and one beside the patient. Two nurses and an anesthesiologist complete the surgical team.

Surgery using the da Vinci typically takes longer than surgery without robotic assistance because the microinstruments and endoscope need to be carefully placed by the surgeon, who must position the robot’s arms accurately in a very small space. The robot cannot move, think, or make decisions on its own. Although the actual operating time for traditional laparoscopic surgery is about an hour shorter than the da Vinci method, the benefits of robotic surgery clearly make it superior.

While the da Vinci surgical system is currently used primarily for prostate and mitral valve repair cases, in late April of this year, it was approved for gynecological procedures, including hysterectomies and the removal of uterine fibroids. (The FDA must approve each surgical procedure separately.)

As with any new technology, however, the da Vinci System has its drawbacks. Its $1.5 million price tag makes it prohibitively expensive for some hospitals. In addition, training for surgeons who wish to learn to use the robot is both expensive and extensive, costing about $10,000 per surgeon. Because of government regulations, hospitals are not permitted to pay that cost, leaving surgeons to decide whether or not to make the investment themselves.

Still, given the benefits the da Vinci provides to patients, it seems likely the use of this technology will increase. The da Vinci provides patients with direct health benefits, according to Dr. Thomas Ahlering, Associate Professor of Urology and Director of the Urological Oncology Department at the University of California Irvine Medical Center. "da Vinci has allowed me to offer my patients a better cancer operation with improved clinical outcomes."

What does the future hold for robotic surgical systems? Quite possibly, a boom in telesurgery, where a surgeon in one location performs surgery on a patient in another. The first telesurgery occurred in 2001, when a New York surgeon operated on a patient in France, removing his gall bladder. Medical teams in both locations were used, linked by fiber optic lines. This lays the foundations for the globalization of surgical procedures, and it allows surgeons to work under a mentor teacher in another location as they learn how to perform operations themselves. The latter can prove especially important in rural areas, where isolation and depressed income can combine to restrict patient care.

Intuitive Surgical has manufactured such a telesurgery system that was recently profiled on the PBS show Innovation Life Inspired. However, the company has chosen not to focus its energies on that area yet. Instead, Intuitive prefers to work closely with surgeons to develop and implement new surgical procedures that improve patients’ lives and redefine medical care. With nearly 300 systems in operation worldwide, the company is prepared to offer just what the doctor ordered, as robotic surgeries continue to grow in popularity."

Source: article by Jonna Lilly

Progressive Engineer
Editor: Tom Gibson
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©2005 Progressive Engineer

As an English major and writer in New Albany, Indiana, Jonna Lilly has taught at several colleges and universities and written for numerous national publications and websites

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