BioEd Online

Meet the robots that can perform surgery from within your own body. Their creators hope that the remote-controlled surgeons are a step towards a time when traditional open surgery is a thing of the past.

Just 8 centimetres long, the devices are designed to be slipped inside a patient's abdomen through a tiny incision. Once inside the body, the robots can be controlled by surgeons either on-site or hundreds of kilometres away.

The miniature medics are equipped with lights and a camera to relay video images back to their operator, and an array of different tools that could help surgeons stop internal bleeding by clamping or cauterizing wounds.

The devices were invented by a team of engineers and doctors from the University of Nebraska Medical Centre, Omaha, and the University of Nebraska in Lincoln.

"This is just the start of things to come," says team member and surgeon Dmitry Oleynikov. "At some point the surgeon's hands won't need to be in the body at all."

Hands across the ocean

Robot-assisted surgery gives doctors greater precision than using their own hands, and it is easier to reach some parts inside the body using flexible mechanical joints.

In 2000, surgeons at the Washington University School of Medicine in St. Louis conducted the first pilot trial of robot-assisted heart surgery¹, and a wide range of procedures now use mechanized instruments. A year later, doctors in New York used a remote-controlled robot to remove a gall bladder from a woman in Strasbourg, France².

Robotic instruments that can be manipulated through a 'keyhole' cut in the patient avoid the trauma caused by larger incisions. But Oleynikov points out that small incisions can constrain the reach of the implements and obscure the surgeon's view of the operating site. Self-contained robots that go right inside are much more versatile, he argues.

"This has been on the cards for a while," says Michael Lamperth, who works on medical robotics at Imperial College London. "There's a lot going on with robots that work from inside the body."

Battery of tests

The devices might even help out on the battlefield, the Nebraska team argues. The robots could be inserted directly into wounds, giving surgeons away from the front line the chance to assess damage and determine how to keep a soldier alive. The team also plans to test a biopsy robot, which could bring back samples of tissue from deep within the body.

And in spring 2006, NASA astronauts will take the robots with them on a trip to the Aquarius underwater laboratory off the coast of Florida, to practice a simulated appendectomy guided by surgeons back on shore.

Lamperth says that miniature robots are best suited to working in the digestive tract, which they can enter through the anus without the need for an incision. "I wouldn't expect them to do heart surgery with these," he says. But Oleynikov points out that their devices should be equally at home within the abdominal or chest cavity.

The devices would have to be approved by the US Food and Drug Administration before seeing widespread use, but the team is hopeful that clinical trials could begin within a year. 'But Lamperth cautions that clinical trials are only the first of many regulatory hurdles the robots will have to clear before they see widespread use.

If trials do prove successful, the robots could become even smaller. "If we were to make 1,000 robots, we would be able to afford customized electrical components that would reduce the size of the robot by half," predicts biomedical engineer Mark Rentschler, part of the Nebraska team.