A 30cm (1ft) snake slowly moves through the body of a man on a spotless table, advancing its way around the liver.
It stops, sniffs to the left, then turns to the right and slithers behind the ribcage. This is a medical robot, guided by a skilled surgeon and designed to get to places doctors are unable to reach without opening a patient up.It is still only a prototype and has not yet been used on real patients - only in the lab. But its designers, from OC Robotics in Bristol, are convinced that once ready and approved, it could help find and remove tumours. The mechanical snake is one of several groundbreaking cancer technologies showcased at this week's International Conference on Oncological Engineering at the University of Leeds. Most of the devices are in very early trial stages, but Safia Danovi from Cancer Research UK says that innovation and research are extremely important in tackling the disease.
"Surgery is a cornerstone treatment for cancer so new technologies making it even more precise and effective are crucial,"she says.
"Thanks to research, innovations such as keyhole surgery and robotics are transforming the treatment landscape for cancer patients and this trend needs to continue."
Cancer accounts for about 13% of worldwide deaths every year, according to the World Health Organization.
Although some cancer treatments involve non-invasive methods, surgeons often need to get inside the body - a procedure that is often risky.
Snake robots could be as minimally invasive as possible with today's technology - they would use body orifices or local incisions as points of entry, says Rob Buckingham, managing director at OC Robotics.
They would allow a surgeon to look and "feel" inside the body - by using cameras and extremely sensitive equipment to provide feedback.
Snake robots could complement a robotic surgical system that has been used for the past decade - the Da Vinci machine, developed by US company Intuitive Surgical.
This mechanism looks like a human-size robot with four "arms" equipped with pincers.
Although it cannot perform surgery autonomously, it has allowed doctors to make complex operations less invasive and more precise.
Image caption Robotic arms designed by DLR could be an alternative to the Da Vinci robot
The Da Vinci is controlled by a surgeon sitting in a nearby chair and looking at a screen displaying the area of the body where the surgery is taking place. The surgeon manipulates the robot by pressing pedals and moving levers.
Many hospitals around the world have opted for the Da Vinci, despite the cost of about £1.4m ($2.2m).
It is about tracking surgical instruments, so that a surgeon sees on a computer screen as a medical tool moves through the body.
Stefan Weber , University of Bern.
Another option is a thin, long mechanical "arm" called Mirosurge, developed by German aerospace centre DLR.
It is also only a prototype, but a DLR engineer who described the technology at the conference says that in the long run, the robot is more versatile than the Da Vinci machine.
"You can attach different tools to it and it can be used either as a one-arm application or as four arms on a surgical table to assist a surgeon controlling them from a workstation," says Sophie Lantermann.
"Also, it has sensors in all the joints, allowing it to detect collisions. For instance, when there's a patient between two arms of the Da Vinci, one arm can hit the other, but our robotic arm detects another arm working next to it.
"It can be a lot cheaper for a hospital because you can use it all day long for different applications."