ROBOTS have been giving surgeons a helping hand for years. In 2016 there were about 4,000 of them scattered around the world’s hospitals, and they took part in 750,000 operations. Most of those procedures were on prostate glands and uteruses. But robots also helped surgeons operate on kidneys, colons, hearts and other organs. Almost all of these machines were, however, the products of a single company. Intuitive Surgical, of Sunnyvale, California, has dominated the surgical-robot market since its device, da Vinci, was cleared for use by the American Food and Drug Administration in 2000.

That, though, is likely to change soon, for two reasons. One is that the continual miniaturisation of electronics means that smarter circuits can be fitted into smaller and more versatile robotic arms than those possessed by Intuitive’s invention. This expands the range of procedures surgical robots can be involved in, and thus the size of the market. The other is that surgical robotics is, as it were, about to go generic. Many of Intuitive’s patents have recently expired. Others are about to do so. As a result, both hopeful startups and established health-care companies are planning to enter their own machines into the field.

Though the word “robot” suggests a machine that can do its work automatically, both da Vinci and its putative competitors are controlled by human surgeons. They are ways of helping a surgeon wield his instruments more precisely than if he were holding them directly. Da Vinci itself has four arms, three of which carry tiny surgical instruments and one of which sports a camera. The surgeon controls these with a console fitted with joysticks and pedals, with the system filtering out any tremors and accidental movements made by its operator. That, combined with the fact that the system uses keyhole surgery (whereby instruments enter the patient’s body through small holes instead of large cuts, making procedures less invasive), reduces risks and speeds up recovery. But at more than $2m for the equipment, plus up to $170,000 a year for maintenance, da Vinci is expensive. If a new generation of surgical robots can make things cheaper, then the benefits of robot-assisted surgery will spread.

Arms and the man

This summer Cambridge Medical Robotics (CMR), a British company, unveiled Versius, a robot that it hopes to start selling next year (a picture of the machine can be seen above). Unlike da Vinci, in which the arms are all attached to a single cart, Versius sports a set of independent arms, each with its own base. These arms are small and light enough to be moved around an operating table as a surgeon pleases, or from one operating theatre to another as the demands of a hospital dictate. This way, the hospital need not dedicate a specific theatre to robotic surgery, and the number of arms can be tailored to the procedure at hand.

Unlike a da Vinci arm, which is like that of an industrial robot, a Versius arm is built like a human one. It has three joints, corresponding to the shoulder, the elbow and the wrist. This means, according to Martin Frost, CMR’s chief executive, that surgeons will be able to use angles and movements they are already familiar with, instead of having to learn a robot-friendly version of a procedure from scratch. The company has yet to decide how much the arms will cost, but Mr Frost expects that operations which employ Versius will work out to be only a few hundred dollars more expensive than those conducted by humans alone. With da Vinci, the difference can amount to thousands.

Versius will compete with da Vinci on its own turf—abdominal and thoracic surgery. Others, though, want to expand robotics into new areas. Medical Microinstruments (MMI), based near Pisa, in Italy, has recently shown off a robot intended for reconstructive microsurgery, a delicate process in which a surgeon repairs damaged blood vessels and nerves while looking through a microscope. This robot allows the surgeon to control a pair of miniature robotic wrists, 3mm across, that have surgical instruments at their tips.

MMI’s device does away with the control console. Instead, the surgeon sits next to the patient and manipulates the instruments with a pair of joysticks that capture his movements and scale them down appropriately. That means he can move as if the vessels really were as big as they appear through the microscope.

Such a robot could even be used for operating on babies. “In their case,” observes Giuseppe Prisco, MMI’s boss, “even ordinary procedures are microsurgery.” The company is now doing preclinical tests. Dr Prisco reckons the market for robotic microsurgery to be worth $2.5bn a year.

A third new firm hoping to build a surgical robot is Auris Robotics. This is the brainchild of Frederic Moll, one of the founders of Intuitive Surgical (though he left more than ten years ago). Auris remains silent about when its robots will reach the market, but the firm’s patent applications give some clues as to what they might look like when they do. Auris appears to be developing a system of flexible arms with cameras and surgical instruments attached, which could enter a patient’s body through his mouth.

That tallies with an announcement the firm made earlier this year, saying that the robot will first be used to remove lung tumours. Lung cancer is the world’s deadliest sort, killing 1.7m people a year. What makes it so deadly, Auris notes, is that it is rarely stopped early. Opening someone’s thorax and removing parts of his lung is risky and traumatic. It is not always worthwhile if the tumour is still small, because small tumours do not necessarily grow big. If they do, though, they are usually lethal if left in situ—but much harder to remove than when they were small. Auris’s design could ease this dilemma by passing surgical instruments from the mouth into the trachea and thence to the precise point inside the affected lung where they are needed, in order to cut away only as much tissue as required.

Auris, CMR and MMI are all startups. But two giants of the medical industry are also joining the quest to build a better surgical robot. One is Medtronic, the world’s largest maker of medical equipment. The other is Johnson & Johnson, which has teamed up with Google’s life-science division, Verily, to form a joint venture called Verb Surgical.

Like Auris, Medtronic is keeping quiet about the design of its robot. But it has said that it plans to begin using it on patients in 2018. Also like Auris, though, some information can be deduced from other sources. In particular, Medtronic has licensed MIRO, a robot developed by Germany’s space agency for the remote control of mechanical arms in space. MIRO is made of lightweight, independent arms. These, presumably, could be fixed directly onto the operating table.

A robot based on MIRO would let surgeons rely on touch as well as sight, since MIRO’s instruments are equipped with force sensors that relay feedback to the joysticks used to operate them, and thus to the operator’s hands. The lack of such haptic feedback (the ability to feel the softness of tissues, and the resistance they offer to the surgeon’s movements) has long been a criticism of da Vinci. Surgeons often rely on touch, for example, to discern healthy from tumorous tissue.

Verb Surgical was formed in 2015 and demonstrated its latest prototype to investors earlier this year. Scott Huennekens, the firm’s boss, says the machine will be particularly suitable for gynaecological, urological, abdominal and thoracic surgery.

Robot, teach thyself

Verb wants not just to build surgical machines, but to get its robots to learn from one another. The firm plans to connect all the machines it sells to the internet. Each bot will record data about, and videos of, every procedure it performs. These will be fed to machine-learning algorithms for analysis, to tease out what works best.

Mr Huennekens compares this to the way Google’s driverless-car division collects data on its vehicles’ journeys in order to improve their performance. A couple of years after its launch, and after processing enough images, the system could start helping surgeons to tell sick tissue from healthy, to decide where nerves and blood vessels are, and to plan procedures accordingly. Later, when the algorithms have swallowed many more years’ worth of data, the robots may be able to help surgeons make complex decisions such as how to deal with unexpected situations, what the best way is to position the robotic arms, and where and how to cut.

As for Intuitive, it, too, has noticed the size of the lung-cancer market. In collaboration with Fosun Pharma, a Chinese firm, it has announced a new system for taking biopsies of early-stage lung cancers in order to determine how threatening they are. It has also announced the launch of the da Vinci X, a lower-cost version of its workhorse. Robots may already be in many theatres, but a bigger part awaits.