In Vivo Robots for Remote surgery
A team of researchers from the University of Nebraska-Lincoln and University of Nebraska Medical Center had recently came up with small robots that could have the potential to revolutionize the way minimally invasive surgery (MIS) is performed. Some of the early prototypes used for testing are shown in the figure below. These medical responders of the future will be at most the size of a lipstick and can be driven remotely around inside the human body to perform tasks like stopping internal bleeding by clamping, clotting or cauterizing wounds. These will be the first robots that actually work from inside the body.
Conventionally, to perform similar operations, one of the surgical techniques used is laparoscopic. In this technique, a small incision is made and a camera is inserted through this incision to provide visual feedback of the operative field. To manipulate the tissues, another long instruments with surgical tools attached to the tip are then inserted through the opening. The benefits of such operations are that there will be minimum operative blood loss and post operative pain. Due to the small incision made for the operation, the recovery time is also shorter.
However, the benefits of laparoscopy are limited to less complex procedures. This is because of the reduced access of such a surgery. Reduced access reduces dexterity, limits perception, increases strain and the likelihood of error, and lengthens procedure times. The operative field is visualized through an electronic interface, and tissue manipulation is performed with long instruments that impose severe ergonomic limitations. The long, rigid instruments and cameras typically used in laparoscopic surgery are constrained to only four degrees of freedom (three rotations and in-out translation) through the entry incision. This prevents the ability to orient the tool tips arbitrarily. Dexterity is significantly reduced because of the lost degrees of freedom and because of motion reversal due to the fulcrum effect at the entry point. Therefore there are limitations on the amount of dexterity and visualization a surgeon has for more complex operations.
To overcome the limitations of dexterity and visualization of laparoscopy, the robots invented by the researchers are small, about 3 inches tall, and are wheeled. They can be inserted totally through standard laparoscopic ports into the body and controlled by surgeons in different locations through computer. Each of the robots will be fitted with a certain tool for carrying out a certain function. For example one such robot maybe fitted with cameras and lights to provide pictures of the operative field to the surgeons while others may be equipped with surgical tools for making incisions or to deliver medicine depending on the tasks. “These remotely controlled in vivo robots provide the surgeon with an enhanced field of view from arbitrary angles, as well as provide dexterous manipulators not constrained by small incisions in the abdominal wall,” Dr. Oleynikov, M.D., director of education and training for the minimally invasive and computer-assisted surgery initiative.
Tests conducted on animals have shown very positive results and performances. Although still in the testing stage, the implication of such an application is far reaching. NASA already has plan to use such a system for its future space mission to attend to astronaut that needs medical attention in space. These robots also have potential use in the battle field where surgeon could remotely help to treat soldiers at the front line.
