Meet the $1.5 million robot that is transforming the ancient art of surgery. Above the patient, the four arms of a half-ton robot move to the beat of remote-controlled instructions. At the end of each arm, surgical instruments probe beneath small incisions between the patient's ribs. This is the face of a new kind of medicine: the doctor's craft wed to the abilities of a relentlessly precise machine called the da Vinci surgical system.

A surgical robot's "hands" have a dexterity and range of motion that is impossible for a human's to match. They can cut, dissect, pull, grip, and stitch while, at the end of another arm, a miniature high-resolution camera tracks them inside the patient's body. Robot hands never tire and never shake.

Under THE ROBOT'S KNIFE.
Across the operating theater from the patient, and with no direct line of sight to the chest or any of the organs within, the surgeon guides the robot. He sits at what looks like a video game console, his hands gripping two joysticks, eyes fastened on a 3-D high-definition screen. The movement of his hands on the joysticks moves the robotic hands, each of which is just a few millimeters in diameter. Each has 7 degrees of freedom and 90 degrees of articulation, effectively making the surgeon ambidextrous.

Originally derived from a U.S. military project for remote surgery on the battlefield, these robotic tools owe much of their civilian development to Intuitive Surgical, a medical technology firm in Sunnyvale, California, that introduced the da Vinci surgical system in 1999. A year later the FDA approved the device for use in general laparoscopic surgery. Many types of procedures are now routinely handled by robotic systems, including prostate removals, heart valve and artery repairs, tumor resections, and hysterectomies.

At right, the da Vinci system is used in cardiac surgery at the St. Pierre Hospital in Brussels. In less than 10 years robotic surgery has grown from a technical curiosity to a common sight. More than 1,000 da Vinci systems costing roughly $1.5 million each have been installed worldwide.

The ROBOT
Robotic surgery promises the patient less trauma and a faster healing process. It stands to reason that a patient undergoing a cardiac procedure (above) should recover more easily from this less-invasive technique, especially compared with standard heart surgery, in which the sternum is cut open and the ribs are literally spread apart. However, these potential benefits have not yet been proved by the medical gold standard of randomized, controlled clinical trials. "Virtually no valid clinical research has been done into whether robotic-assisted surgery is able to offer greater benefits to the patient than traditional surgery," says Diane Robertson, director of Health Technology Assessment at the ECRI Institute, a nonprofit health sciences research group.

For surgeons, the virtues of a robotic assistant include enhanced precision and the ability to work in smaller body cavities. The rise of robot operators is also fueled by the effort to avoid medical complications. Surgeon-guided robotic hands allow repairs to be less invasive, permitting faster post-op recovery. Collaboration is also possible: The most recent da Vinci system can accommodate two surgeons, each sitting at a separate console.

Coming next: even more automation. In the future, miniature robots may be designed to be inserted into the body and operated in much the same way one would pilot a remote-controlled vehicle. Researchers at the University of Nebraska are testing a three-inch-long bot that can be placed in the abdomen, streaming live footage of injuries as it goes. The machine might even carry out treatment, such as cauterizing injuries to stop internal bleeding or cutting away damaged tissue using a pair of remote-controlled scalpels.

The DRIVER
As chief of cardiac surgery at Children's Hospital in Boston, Pedro del Nido (right) uses the da Vinci system to manipulate the major blood vessels outside his patients' hearts. "Being physically separated from the patient is a huge conceptual obstacle," he says. "But it offers some tremendous advances." In conjunction with Pierre DuPont, a professor of mechanical and biomedi-cal engineering at Boston University, del Nido is developing a robotic "needle" that carries out procedures inside the heart while it is still beating. The technique would improve complicated surgeries such as those correcting congenital heart defects (the most common birth defect) in tiny fetal and pediatric hearts and those repairing the effects of heart disease in older patients.

Del Nido and DuPont's system, called the steer-able needle, can turn corners in the body. It is inserted through a small incision into a blood vessel and then snaked through the vessel to the target area of the heart. "You operate the robot as if you were holding a pen," del Nido says. "You move the pen and the robot moves." The National Institutes of Health granted the team $10 million to develop the steerable needle.

If the system works as planned, it might allow surgeons to work on the inside of the heart without having to stop it first. "Then we won't have to put patients on bypass machines," del Nido says. "We can operate in a far less invasive way, which will hopefully reduce risks associated with this kind of surgery."

From Discover magazine (Summer 2009).