Snake robots for scar-free surgery

The Engineer
Nov 14, 2011

Snake arm robots were originally developed as remote manipulators for hazardous and constrained environments, such as the inside of nuclear reactors


Snakes and bladders: UK-developed robots are helping realise the scar-free potential of natural orifice surgery

Of all the areas where engineering and technology is affecting medicine, surgery is probably the one where it has the potential to make the biggest changes. New imaging techniques and improved instruments help surgeons to identify the regions where they must operate and assist their intricate work.

Robot surgeons, although poorly named, are at the forefront of one of the biggest technology-led changes. Rather than carrying out surgery without human intervention, as the name implies, they are remotely operated devices that allow surgeons to work through small incisions, rather than the large holes needed in conventional surgery for surgeons to see what they are doing. This reduces the size of wounds and therefore scarring, and reduces the time needed for recovery.

One particularly striking form of remote surgery promises the possibility of doing away with scars altogether. Known as NOTES (Natural Orifice Transluminal Endoscopic Surgery), the technique takes advantage of the holes that are already in the body as access points for surgery. Rather than making an incision in the outside of the body, the surgeon goes in via the mouth, rectum or vagina, makes an incision through the wall of the orifice (this is the ’transluminal’ part of the acronym) and then burrows through to reach the target organ. The result is no visible scar and no incision-related complications.

TIM FRANCOIS, OC ROBOTICS

But there’s no way this can be done without robotic assistance. While endoscopes are now commonly used to see inside the body via natural orifices, they don’t have the mobility necessary to navigate as precisely as NOTES requires, and their mechanical structure, although fine for mounting a passive camera on to, isn’t suitable as a mount for surgical instruments; these need to be mounted on a firm platform, which doesn’t move when the instruments press against or cut into tissues.

The first NOTES procedures were carried out in 2007 and the technique has been developed around the world, with appendixes, kidneys and gallbladders being removed. To date, NOTES operations have used conventional, although adapted, endoscopes, and have had some success: in the UK, the technique has been used for gallbladder surgery on female patients. However, to develop the technique further, dedicated instruments are needed; in particular, the robot that takes the instruments inside the body.

Two UK teams are currently working on robots for NOTES. At Imperial College London, a team from the departments of surgery, computing and biomedical engineering, funded by the Wellcome Trust, is working on iSnake, a combined surgical robot and imaging device. Meanwhile, Bristol-based OC Robotics is developing its snake-arm robots, which are used as remote manipulators in hazardous areas, to work within the human body, aided by a grant from the Technology Strategy Board.
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