One of the most promising and impressive applications in medical robotics concerns surgery. Operations are difficult procedures that involve cutting through tissues, damaging bones and nerves in the process. In traditional open-heart surgery, for instance, the surgeon makes a 25 to 30 centimetre incision, then accesses the heart by splitting the breast bone and spreading open the rib cage. This exposes patients to possible infections and results in painful wounds, which take time to heal.
Laparoscopic surgery, also called MIS (minimally-invasive surgery) was introduced in the 1970s. It requires one or more small incisions (generally 1-2 cm) to introduce surgical instruments (scissors, scalpel, clip appliers, etc.) and an endoscopic lens linked to a camera that magnifies and displays images of the operative field and of the instruments onto TV monitors. MIS offers many advantages over open surgery: smaller incisions that reduce haemorrhaging, pain and risks of infection, shortening hospital stays and recovery, and hence lowering costs.
However, MIS presents certain limitations in spite of its benefits, notably the difficulties surgeons have in manipulating instruments, which move in the opposite direction to their hand movements, impaired visual perception and a lack of feedback in terms of the force being applied to tissues. It is also not adapted to complex procedures.
Making minimally-invasive surgery even less invasive...
The introduction of robotics in surgery has improved MIS greatly, extending it beyond its initial applications (mainly gall bladder and prostate removal, gastrointestinal and gynaecological surgery and urology). Robots are now used for more complex operations in cardiothoracic, orthopaedic and general surgery, and even recently (July 2011) for internal radiation therapy. Precise implantation of Caesium-131 isotopes enables cancers that cannot be surgically removed to be treated, thus avoiding lengthy radiation treatment.
The most widespread complex internal surgery robotic equipment, now used in dozens of countries, is the da Vinci® system developed by Intuitive Surgical, a US (United States) company. It is operated by one or more surgeons sitting at consoles and using 3D high-definition vision to guide robot-controlled surgical instruments that reproduce precisely their movements. It extends the benefits of MIS to traditional open surgery procedures and is being used in an ever-expanding range of operations.
In orthopaedic and spinal surgery, robots can be used to position joint replacements and implants more precisely than a surgeon's hands are able to. Studies on 840 patients who underwent spinal surgery showed that robot-guided procedures had achieved 98,57 % accuracy in placing implants, a much better result than that reached with traditional operations. Similar rates are attained in joint replacements, a significant result as misalignment of joint replacements is one of the most common causes of complications in orthopaedic surgery, often requiring additional operations to be performed.
Non-invasive procedures are another field where robots can be very useful. The US firm Accuray Incorporated has developed CyberKnife®, a robotic radiosurgery non-invasive technology that enables high-precision radiation therapy using continual image guidance technology and computer-controlled robotic mobility. According to Accuray, CyberKnife can be an alternative to open surgery requiring "five or fewer outpatient visits" to treat complex cancerous and non-cancerous tumours anywhere in the body using "thousands of beam angles and real-time corrections for target motion".
Further advances being made in medical robotic-related fields, such as force feedback, allowing surgeons to feel the pressure they apply when operating, should make robotic surgery even safer and more accurate in the near future. Contrary to widely-held misconceptions, in the vast majority of cases robots do not perform the operations independently, but are controlled by a surgeon. Robotic surgery is as good (or bad) as the surgeon that controls it.
Medical service robots
As the world's population ages and requires more care, medical service robots are being developed to support both patients and medical staff. Japan, with a fast-ageing population, is at the forefront of developments in this domain.
Devices capable of lifting and assisting disabled and elderly patients include exoskeletons that allow wearers to carry about four to five times as much weight as they could unaided, and robotic aids designed to lift and move people who are too weak or ill to sit, walk, or stand by themselves are being developed. Nursebots, designed to help elderly people cope with day-to-day activities, enabling them to live at home and reducing strains on medical infrastructure and costs, are being introduced. Some of these even have telepresence capabilities, allowing medical staff to monitor patients' conditions remotely.
Underwater and aerial remotely-controlled robots were also deployed in Fukushima and elsewhere to survey sites too remote or hazardous for human intervention. Robots can be deployed in cases of natural or industrial disasters to assess damage or explore rubble for survivors in places inaccessible or too dangerous for humans or even dogs. For instance, snake- or worm-shaped robots that can wriggle their way past obstacles and report to rescuers are being developed for this purpose.
Robot-based solutions can also improve therapy after strokes, spinal cord injuries or other lesions of the central nervous system. RELab (Rehabilitation Engineering Lab), at the Swiss Federal Institute of Technology in Zürich, has developed a robot to automate treadmill training to help patients regain mobility faster and ARMinIII, an exoskeletal machine for arm rehabilitation. These robots intelligently adapt their behaviour to the patients' individual capabilities.
Other robotic applications in healthcare include pharmacy robots, which prepare and dispense intravenous drugs directly in a syringe using bar code scanning and introducing several confirmation steps to prevent medication errors, and remote presence robotic platforms that can connect rural hospital systems and improve patient care in remote areas.
Training of surgeons, dentists and nurses can also be made more efficient and realistic with robots that simulate live patients' pain or discomfort.
A significant hurdle to overcome for medical robotics is the high purchase price of the equipment: in July 2011, the Asian Heart Institute hospital in Mumbai, India, bought a da Vinci Si System for USD 2,5 million; a Regina robotic aid used to lift and move patients is reported to cost between USD 60 000 and USD 80 000. However, many factors have to be taken into account when assessing the cost-benefit and return on investments of medical robots.
According to a study from the US Agency for Healthcare Research and Quality, surgical complications (such as postoperative infections and bleeding, or surgical objects left in wounds) resulted in 2,4 million extra days of hospitalization, additional charges of USD 9,3 billion and 32 000 unnecessary deaths in 2000. The use of surgical robots cuts significantly some of these hazards and the overall length of hospitalization. The fact that robotic surgery equipment is now being introduced in many developing countries also shows that it is seen as cost-effective.
The medical and economic benefits of using medical robotics and the rapid technological advances made in the field suggest that it will be extended to many more medical procedures in coming years.
International Standards essential to the future of medical robotics
As medical robotics is a relatively new domain, the preparation of International Standards is now emerging as a priority. The IEC through its TC (Technical Committee) 62: Electrical equipment in medical practice and its SCs (Subcommittees) "prepares international standards and technical reports concerning the manufacture, installation and application of electrical equipment used in medical practice". TC 62 was established in 1968, but has not been involved in the preparation of standards for medical robots so far.
In June 2011 JWG (Joint Working Group) 9 was formed by IEC SC 62A: Common aspects of electrical equipment used in medical practice, with ISO (International Organization for Standardization) TC 184/SC 2. "The new JWG is attracting significant global attention as well as interest from both robotics and medical experts to participate in its work," its convenor, Gurvinder Virk, says. "Important tasks for JWG 9," he adds, "are to formulate the key features that medical robots introduce when used in medical electrical equipment; to determine the boundary between medical and non-medical robotic applications; and how to classify the various possible types of medical robots."
This JWG will prepare and publish International Standards that will help develop safe medical robots and contribute to their global introduction.