Tiny robots for less invasive surgery

Surgical procedures have improved rapidly in recent years aided by technology that is gradually making the surgeon's scalpel a thing of the past -- increasingly replaced by robotics, miniature devices and innovative procedures that have fewer health risks, speed patient recovery and leave less scarring. But there is always room for further improvement.

'There are issues with abdominal surgery at present, both with the technology and the procedure,' says Professor Arianna Menciassi of the BioRobotics Institute at Scuola Superiore Sant'Anna in Italy.

At present, abdominal surgery is either performed by a surgeon manually, using a key-hole technique also known as laparoscopy, or with the aid of a teleoperated robotic device. The most widely used surgical robot for the procedure is highly precise -- more so than manual surgery -- but it is also bulky, expensive and still requires several incisions to be made in the abdomen.

This current system makes the surgery easier for the surgeon, 'but it is just as invasive as the traditional laparoscopic procedure for the patient, requiring a minimum of four incisions in the abdomen: two for the robotic tools, one for further manoeuvres and one for a camera,' Prof Menciassi explains. 'We set out to develop an alternative system using state-of-the-art micro-robotics and micro-system technologies that would be less expensive and less invasive.'

Working in the 'Array of robots augmenting the kinematics of endoluminal surgery' (Araknes) project, Prof Menciassi and a team of researchers from across Europe focused on an approach to abdominal surgery that integrates the advantages of traditional open surgery, 'Minimally invasive surgery' (MIS) -- also known as laparoscopic or key-hole surgery -- and robotic surgery. Supported by EUR 8.1 million in funding from the European Commission, the Araknes team developed highly innovative devices and technologies that greatly reduce the invasiveness of surgical procedures, minimise scarring, decrease the risk of infection and speed patient recovery time at potentially much lower cost than existing commercial systems.

One of the results of Araknes is a teleoperated robotic system called the 'Single-port laparoscopy bimanual robot' (Sprint) that, like the DaVinci system, replicates with high precision the hand movements of a surgeon sitting at a console interface. However, the system is specifically designed for 'Single-port laparoscopy' (SPL) -- a relatively new type of key-hole surgery in which the surgeon operates through a single incision, usually in the patient's navel.

'Instead of four incisions, this technique uses only one incision -- the access port -- of around three centimetres in diameter. And because the incision is made through the navel -- a natural scar -- there is no visible scarring,' Prof Menciassi, the Araknes scientific manager, explains.

Sprint is composed of two arms with six degrees of freedom of movement with rotating grippers at the end, providing a very high degree of dexterity for performing a wide variety of surgical tasks inside the patient's body.

'The arms function much like our own and, through the teleoperated interface, replicate precisely the movements of the surgeon who views the procedure via a 3D high-definition camera,' Prof Menciassi says.

Crucially, thanks to state-of-the-art micro-robotics technology, the motors that control the grippers and the 'elbows' of each arm are located on the device, while the motors for the 'shoulders' are external.

'This is a key difference with existing commercial systems, as it means the entire system is much less bulky. It fits much more easily into the operating room and allows better access to the patient,' the project manager explains.

The reduced size of the system was one of several highly regarded features by surgeons who conducted in-vivo tests on a pig at a lab run by project partner Novineon in Germany in January.

'Surgeons accustomed to using DaVinci welcomed the small size and increased visibility of the patient as well as the reduced invasiveness, while surgeons who normally perform the single-port procedure manually saw an immediate advantage in terms of precision,' Prof Menciassi says.

Another device developed by the Araknes team is designed to eliminate the need for incisions entirely. Developed for 'Natural orifice translumenal endoscopic surgery' (Notes), the device consists of a magnetic platform coupled with miniature robotic arms that can be inserted into the patient through a natural orifice such as the mouth or anus with no other incision necessary.

Notes itself is still considered an experimental surgical technique, but one that potentially has many advantages for the patient over invasive methods.

'The Notes platform is experimental, and unlikely to be used in surgery for some time for both technical and clinical reasons. Nonetheless, it consists of many innovative enabling technologies that could find more immediate applications,' the project manager says.

On the other hand, the Sprint robotic system is much closer to market in light of the success of the in-vivo trials carried out by the project partners. The Sprint technology is currently being patented and the partners are looking to use it as the basis for a commercial system.

'We are currently seeking funding from both public and private sources for further development,' Prof. Menciassi explains. 'It's still a prototype, but we are confident that if produced commercially it would be less expensive than existing systems. Plus the faster recovery time using the SPL technique should reduce hospitalisation time for the patient, lowering healthcare costs.'

The Araknes team initially focused their work on developing systems for weight-loss surgery, a procedure to reduce the size of the stomach, or bypass it entirely, that is undergone by tens of thousands of Europeans each year. However, Prof Menciassi emphasizes that the devices could be used for any type of abdominal surgery, for example, to remove cancerous tumours or treat problems with the heart, liver or kidneys.