Cambridge Medical Robotics has developed a device that could make keyhole surgery universally accessible and affordable.

The company expects Versius to be the world's smallest surgical robot, and one-third the size of the current market leader, the da Vinci Surgical System, which measures 36 inches in width and 68.5 to 97 inches in height. It integrates technology from mobile phones and the space industry in a robotic design that mimics a human surgeon.

The Versius surgical robot. Image credit: Cambridge Medical Robotics (CMR)
The Versius surgical robot. Image credit: Cambridge Medical Robotics (CMR)

Keyhole surgery has enormous benefits but technical barriers block access to millions of patients, who instead have to undergo more invasive procedures. The Cambridge Medical Robotics (CMR) offering is designed to overcome these hurdles.

Problems with keyhole surgery

Keyhole surgery is a minimally invasive procedure also known as laparoscopy that involves doctors stabbing tiny incisions into the body through which they can then insert thin, long instruments to conduct the operation. The result is that wounds can heal much faster and leave less scarring, but the cost and complexity of the procedure have kept it out of reach for most patients.

Surgeons have to handle long tools mounted on scissor handles while looking at the image of the operation on a monitor. The instruments are tricky to control and the two-dimensional image reduces their depth perception.

"Because it's extraordinarily difficult, there aren't enough surgeons who have mastered all the techniques, and because of that a great many people - about six million a year - still have open procedures rather than keyhole procedures," CMR's technology director Luke Hares told Techworld.

"The solution is to give a surgeon a better tool. They can understand the procedure, it's just that physically doing it is so difficult."

Sophisticated robots are a possible solution. An American company called Intuitive Surgical has dominated the field of laparoscopic surgical robotics since it created the da Vinci System in 2000, but its cost remains prohibitive and its form limits its functions. There are approximately 4,000 of the devices in operation, but they only perform around 750,000 procedures a year between them.

"One of the weaknesses of the existing solution is that it works pretty well for pelvic-type procedures, but as you move away from those you end up having to modify the procedures more and more to live with the mechanical restrictions of the system," says Hares.

How Versius works

CMR's Versius replicates the techniques of the human surgeons who control it and fits existing operating room workflows, but most importantly it is capable of conducting the vast majority of laparoscopic procedures.

Doctors and their patients come in all shapes and sizes, and every surgeon has their personal performances in the operating rooms. CMR turned to nature to find inspiration for its machine.

"What we ended up doing is copying the only system out there that currently does all laparoscopic procedures, and that is a human being," says Hares.

"Our robot arms are about as strong, about as fast, but about as slim and about as flexible as human arms, and that means that they've got the reach necessary to be able to get everywhere that human arms can get to.

"Critically, they can hold the instrument in the same way," Hares explains. "A human being holds a laparoscopic instrument straight out from his arm like a gun, so the instrument shaft is pointed out like your index finger would be if you were pointing at something."

Versius replicates this range of motion through a sophisticated wrist joint comprised of four axes, rather than a typical three-axis robot wrist. This gives it the flexibility to point an operating instrument straight on at a sharp angle to the forearm of the robot. The size of Versius and the flexibility of its robotic arms mean that three or four can fit around a single patient.

"It's much more human in scale. It fits into existing ORs, you can move it about easily, it's a modular system so if you're doing a simple procedure and you just need three arms, you can just have three arms, and the other ones can be away in the cupboard.

"And if you're doing something more complicated, you can bring out more arms and just plug them in and you're ready to go. It's a much more lightweight console. The surgeon sits at a console in order to control it, but he's sitting in front of a 3D monitor and he's able to see the patient.

"He's able to see the people by the [operating room] bed, they're able to see him and so you've still got all the non-verbal cues and communication going on. They can see a much more human scale system, and one that they can see themselves using, and being able to use very broadly."

The tech behind Versius

The unique needs of Versius meant the robot would require a complicated combination of motors, gearboxes, bearings and electronics.

CMR sought solutions that had been developed in other applications and could be integrated in their own product. They found some of the tech they need in the mobile phones and space travel sectors.

Unlike the majority of robots that are installed in a production line for years, Versius needs to be moved around after every procedure. In order to do that it needs to be lightweight and slim, and contain electronics of minimal size.

In Versius, all the electronics are embedded in the arm, using the type of Printed Circuit Board (PCB) fabrication technology that was originally designed for mobile phones. This form of miniaturisation supports big processing capabilities that can function at low power and within a compact form. Versius can use it to integrate eight microprocessors that run up its arm, all controlled by a small PC. 

The gearboxes on the system use harmonic drives that were developed for the space industry. They allow it to retain a perfectly steady position through the whole spectrum of its movements. The wrist design uses another sophisticated gear set called spiroid that is known for its compactness and strength. Hare believes it has never before been used in robotic applications.

"The system is checking its position, rerunning all its kinematics calculations and adjusting the torques that each motor is putting out at a rate of five kilohertz, so 5,000 times a second," he explains.

The future of Versius

Versius is designed to perform the vast majority of laparoscopic procedures. These include pelvic procedures such as hysterectomies; prostate surgery for cancer removal; colorectal procedures to remove sections of the bowel; renal and kidney procedures; and various forms of surgery around the stomach. The more procedures it can do, the more affordable it becomes.

"Essentially, unless it's major transplant surgery, most procedures that take place in the torso you can do laparoscopically and you can, therefore, do with a Versius," says Hare

"Just as we want to be disruptive on technology, we also want to be disruptive about how we bring it to market. We're keen to move away from the existing model, which is that hospitals pay a phenomenal amount of capital for the system, then pay an awful lot for the semi-disposable instruments, and then they pay a lot for the service charge. We feel we can do better than that."

They want to make it more capital-efficient and envision Versius becoming a price-per-procedure payment model, a good fit with how hospitals are currently reimbursed.

Hare says the reaction from surgeons has been "overwhelmingly positive."

CMR anticipate Versius coming to operating rooms at the end of 2018, after tests that prove the safe and effective performance necessary to allow clinical trials.

It will enter a big-money market. Robot-assisted minimal access surgery currently generates global annual revenues of approximately $4 billion, and are expected to reach $20 billion by 2025, according to forecasts by Accuray Research.

CMR faces competition from giants of the industry. Google and pharmaceutical giant Johnson & Johnson are producing their own competitor Verb, and the medical devices company Medtronics has its own plans to enter the market. Hare believes there's space in the market for all of them, and that the size and setup of CMR gives it strengths missing in its bigger rivals.

"It's not a showstopper, in the sense that it's a massive unmet need. The market here isn't the 750,000 procedures that Intuitive do at the moment, the market here is the millions more procedures that should be done laparoscopically, and there's certainly every reason to believe that we can succeed in the market.

"The other thing that we have is a huge amount of agility and nimbleness. We are unconstrained by the impact of what we are doing on our existing business for example.

"We can be very responsive to what surgeons want quickly, but critically we do believe that we were the only company, about four years ago, that dared ask itself how do you build a system that just does everything."