The “Sci-Fi Surgery: Medical Robots” exhibition explored the pioneering field of medical robotics from the first autonomous device used for transurethral resection of the prostate, to visionary mini-robots that are designed to crawl, swim and explore inside the human body. Since the first industrial manufacturing arms appeared in factories almost fifty years ago, robots have been designed to perform tasks deemed too tedious, dangerous or precise for humans. They have been used to build micro-processors, explore space and defuse bombs. Only more recently have robots been used to tackle major medical challenges, but they are now used in a range of surgical specialties, including orthopaedics, neurosurgery and many minimally invasive procedures. Medical robots have been designed to increase surgeons’ dexterity and control, to support busy nursing staff, or to help doctors make diagnoses. Some are proven technologies, while others are still at the experimental stage.
Surgical robots 1985-2009
The exhibition commentary explained that there is no set definition for what constitutes a “robot”, but it is generally used to describe a machine – usually computer-controlled – that is capable of movement and interaction with its environment. The word “robot” comes from the Czech “robota”, meaning labour. The term was popularised by Karel Capek’s play “Rossum’s Universal Robots” (1921) where it described factory made, artificial workers. The first surgical robots were based on industrial machines. In 1985, surgeons used a robot called the Puma 560 to position a needle during a brain biopsy. The “Sci-Fi Surgery: Medical Robots” exhibition explored the pioneering field of medical robotics from the first autonomous device used for transurethral resection of the prostate, to visionary mini-robots that are designed to crawl, swim and explore inside the human body. Since the first industrial manufacturing arms appeared in factories almost fifty years ago, robots have been designed to perform tasks deemed too tedious, dangerous or precise for humans. They have been used to build micro-processors, explore space and defuse bombs. Only more recently have robots been used to tackle major medical challenges, but they are now used in a range of surgical specialties, including orthopaedics, neurosurgery and many minimally invasive procedures. Medical robots have been designed to increase surgeons’ dexterity and control, to support busy nursing staff, or to help doctors make diagnoses. Some are proven technologies, while others are still at the experimental stage.
Surgical robots 1985-2009
The exhibition commentary explained that there is no set definition for what constitutes a “robot”, but it is generally used to describe a machine – usually computer-controlled – that is capable of movement and interaction with its environment. The word “robot” comes from the Czech “robota”, meaning labour. The term was popularised by Karel Capek’s play “Rossum’s Universal Robots” (1921) where it described factory made, artificial workers. The first surgical robots were based on industrial machines. In 1985, surgeons used a robot called the Puma 560 to position a needle during a brain biopsy. This led researchers to design purposebuilt surgical robots and, in 1991, the Probot became the first robot to actively remove tissue from a patient. Developed by Imperial College London and Guy’s Hospital, it was used for transurethral resection of the prostate (TURP), where part of an enlarged prostate gland is removed. The Probot was an autonomous device: the surgeon put the machine into position, and stood back as the robot performed the operation.1 However, this passive role made surgeons uneasy and led to a move towards “shared control” where the surgeon performs the operation with the help of a robot. One such device, the Acrobot Sculptor, was first developed by Imperial College London, in 2002. The Acrobot is designed to assist with accurate placement of the artificial knee joint during knee replacement surgery. The surgeon uses a handle near the end of the robotic arm to guide a high speed cutter, while a system of “active constraint” prevents the surgeon from removing bone outside a pre-programmed “safe” area. The “active constraint” concept was used successfully in a randomised, double blind comparative clinical investigation in 2004, where 13 unicondylar knee replacements were carried out using the Acrobot system and 15 were performed conventionally.2 The study demonstrated that the Acrobot system consistently and accurately enables the positioning of a prosthetic implant according to a surgical plan. The investigation found that 13/13 Acrobot cases were implanted within 2° of a desired orientation versus 6/15 for the conventional cases.3 The bar chart (right) summarises these results.
Rise of the master-slave robots
In the late 1980s the US army and the Stanford Research Institute began investigating remote surgery (telesurgery), where the surgeon and the patient are in different physical locations. Their aim was to develop technology for use in remote war zones. They designed the first master-slave telemanipulator, later known as “da Vinci”. Telemanipulators can operate over long distances. In 2001, a surgeon in New York used a robot called “Zeus” to remove a gallbladder from a patient in France. Master-slave robots are also useful in other ways. The da Vinci was designed to help surgeons perform delicate minimally invasive surgery, operating through tiny incisions in the body. Such procedures can be difficult, because the surgeon’s view of the operation is limited. Masterslave robots help by providing magnified, 3D vision and by scaling down the movements of the instruments, allowing surgeons to operate with much greater accuracy. There are limitations, however. Master-slave telemanipulators are bulky and expensive. Furthermore, robotic surgery has yet to resolve one major drawback of minimally invasive surgery – surgeons still cannot feel the patient’s body as they would during traditional surgery. Research is currently underway to create “haptic feedback” to overcome this draw-back – the aim is to develop technology that interfaces to the user via the sense of touch. “In traditional surgery, surgeons put their hands inside the body and can feel the difference between the tissues. Even with traditional minimally invasive surgery, where the surgeon uses long instruments, there is some haptic feedback. However, telemanipulators do not provide feedback in this way. Some surgeons argue that the benefits that they gain from using this type of surgery compensate for the loss of feeling, but there is currently debate over this issue,” explained curator Sarah Pearson. “A number of universities are now investigating whether it is possible to obtain some kind of force feedback – to compensate for the lack of touch.”
Laparoscopic camera controllers
Early last year, Prosurgics launched a robotic camera controller for minimally invasive surgery aimed at making robotics more affordable. Traditionally, the laparoscopic camera has been moved by an assistant, but the FreeHand allows the surgeons to control the camera themselves using head movements and a foot pedal. This provides them with a steady image and complete control over the field of view. The company has reported that the system is contributing to a shorter procedure time of 20% to 30% in laparoscopic surgery, while the first colorectal surgeries in the US were performed earlier in 2009, at the Rush University Medical Center in Chicago. Surgeons Dr Marc Brand and Dr Theodore Saclarides successfully completed three laparoscopic hemicolectomies using FreeHand. Dr Brand commented: “A laparoscopic colectomy is uniquely challenging in that a wide field of view is required, from the ribs to the pelvis. FreeHand provided visual coverage of the entire area. It also gave me control so that I did not have to interrupt dissection to reposition the camera or tell a person holding the camera what to do; returning control of the camera view to the surgeon allows for the image to lead the procedure instead of follow it. It’s like having an extra pair of hands.”4
‘Nursebots’ and automation of routine tasks
Robots are being designed to support virtually every area of patient care, from monitoring health to aiding rehabilitation, dispensing medicine and even helping with ward rounds. Telemedicine and remote patient monitoring can provide immediate, round-the-clock observation. Such technologies are no substitute for face-to-face care, but they could help to relieve pressure from busy doctors and nurses. The ultimate aim is to improve patients’ quality of life. Some devices may help the elderly and people with chronic conditions to live more independently and reduce the amount of time they spend in hospital. An example of R&D currently in progress is the EU funded project IWARD, which is looking to develop three robot nurses that could perform a range of tasks for nurses, such as checking temperatures and blood pressure and generally easing the burden on hospital staff so they can spend more time with patients. The robotic nurses could also help to keep wards cleaner and reduce infections such as MRSA. Each “nursebot” will consist of a basic platform mounted with a module of sensors and equipment for different tasks. For example, a robot could be fitted with a laser thermometer to measure body heat from a distance or cleaning equipment to mop up spills. Another task could be to guide visitors around the hospital. Each robot would be fitted with a suite of sensors, allowing it to move around the hospital, using proximity sensors to avoid collisions and inbuilt cameras to explore its environment. Information could be communicated between the robots by using either a wireless Local Area Network (LAN) or Bluetooth technology or even infrared lasers. The robots could then communicate with patients and pass messages on to staff. It is hoped that a three-robot prototype system will be ready by 2010. Interestingly, designers of such robots have tended to steer away from giving “human” characteristics to their appearance – apparently patients, in the UK, for example, are uncomfortable with “humanoid” robots and find them somewhat “sinister” – perhaps fuelled by science fiction, although attitudes vary between cultures. Robots have also been designed to perform routine tasks such as taking blood samples. One such prototype was developed by Imperial College London in 2001 called the “Bloodbot”. Although it is not currently commercially available, the device has been designed to improve accuracy and to reduce patient discomfort. The Bloodbot identifies the location of a suitable vein by pressing a probe against the surface tissue of the ante-cubital fossa and measuring the force on the probe. The difference in the characteristics of the tissue from its surroundings, in response to the applied force, indicates the presence of a vein. Once a suitable vein has been found, it inserts a needle under force control. When the needle penetrates the vein (identified by its force/position profile), the control system prevents further insertion, thus avoiding overshooting the vein. The system has been tested on a “dummy” arm (made by Limbs and Things), which was designed to accurately simulate the behaviour of the tissues of the ante-cubital fossa. Imperial College reported that the results obtained were consistently good. The ideal situation would have been to test the system on a wide range of patients. However, because of the difficultly in obtaining permission to test medical devices, the system was tested on only one human patient. The vein location phase was tested on the patient and the vein was located correctly about 78% of the time. The needle insertion was also tested and worked. This test was not repeated, so as to avoid multiple scarring.5 Although there is some initial data on the robot’s accuracy, it is still a matter for debate as to how well the concept would be tolerated by patients. Would nervous patients feel “vulnerable” and trust the technology? How would they feel about an “invasive” technology that is unable to perceive their anxiety, respond if they are in pain or provide reassurance? Would they still feel in control of the situation? These are questions that may need to be addressed in the future. Another device designed for routine tasks is aimed at assisting patient monitoring. The Sensium “Digital Plaster” is a disposable device developed by Toumaz Technology in 2009, which monitors and transmits patient’s temperature, heart rate, respiration rate and other data. Data is continuously sent to a computer database and if results fall outside predefined “safe” ranges, the patient, doctor or carer is alerted. The Sensium digital plaster is targeted for use in clinical monitoring applications such as acute care, general ward environments, tele-care, chronic disease monitoring, and in care home settings. A trial of the body monitoring system is being conducted by Imperial College London at St Mary’s Hospital (part of Imperial College Healthcare NHS Trust) and is being funded by global healthcare corporation CareFusion. The focus of the trial will be to verify that the physiological data acquired by the digital plaster system within a clinical setting is equivalent to that acquired using current goldstandard monitors in use in hospitals – equipment that is often bulky, expensive and fixed, so that patient mobility is impaired. Dr Stephen Brett, a consultant in intensive care medicine at Imperial College Healthcare NHS Trust, who is leading the trial, explained: “This technology has the potential to improve the capturing of patient’s vital signs within all areas of the hospital – enabling key physiological data to be acquired at an increased frequency, with the minimum of inconvenience to patients, and without the requirement to connect patients to immobile pieces of equipment. This raises the possibility of technology improving hospital safety systems, enhancing the efficiency of adding vital sign data to patient records, and potentially freeing valuable nursing staff time for other patient care responsibilities.”6
Tiny robots explore the body
Bringing science fiction closer to reality is the development of miniature medical robots, which may soon be sent into patients’ bodies to diagnose problems and deliver localised treatment. Researchers believe that such devices could allow doctors to reach inaccessible areas while causing less damage and pain than other techniques. These robots are still at the development stage. The most advanced are “mini-robots” usually 10 to 15 mm in diameter, which are designed to examine the gastrointestinal tract (oesophagus, stomach, small intestine and colon). They could provide an alternative to traditional endoscopy, which is essential for diagnosis but can be uncomfortable for the patient. Other mini-robots are being designed for endoluminal and transluminal surgery, where operations are carried out using instruments inserted via the mouth or anus. Building robots on a smaller scale is more difficult. Researchers have designed motors for “micro-robots” less than a millimetre across that could one day be injected into the bloodstream. Some scientists believe that in the future “nano-robots” measuring less than a thousandth of a millimetre will be used, but at the moment this idea remains speculative. Dr Arianna Menciassi, associate professor of Biomedical Robotics at Scuola Superiore Sant’Anna, Italy, commented: “Many mini and microrobots have biologically inspired designs which emulate the crawling and wriggling motion of worms and insects, or the swimming motion of bacteria. We turned to biological inspiration because such organisms have locomotion systems suited to unstructured, slippery environments and are ideally suited for use in the human body.” An example of some of these devices includes a prototype robotic camera pill developed by Scuola Superiore Sant’Anna, with the support of the European Commission and of the Intelligent Microsystem Center in Seoul, South Korea. The designers hope that this remote-controlled camera pill for endoscopy of the gastrointestinal (GI) tract will be more comfortable for the patient than traditional fibre-optic endoscopes which are pushed into the body though the mouth or anus. It has hooked legs to gently grip onto the intestinal wall, allowing the doctors to guide it and stop it at points of interest. The overall goal of the project, which is at prototype stage, is to provide a technology that can dramatically improve early detection and treatment of GI early cancers and cancer precursors.7 Dr Arianna Menciassi has previously highlighted the need for greater control over camera pills and commented: “Non-robotic camera pills are like watching the view from a train window. If you see something interesting, there is no way to turn back and get a better look.” Current research is seeking a solution to this problem, therefore. A prototype swimming camera capsule for gastroscopy has also been developed by Scuola Superiore Sant’Anna. The patient would drink half a litre of polyethylene glycol solution before swallowing this wireless capsule. The liquid would distend the stomach enabling the robot to swim in three dimensions. Additionally, the centre has developed prototype ARES robots (Assembling Reconfigurable Endoluminal Surgical System). Up to fifteen separate modules would be swallowed by a patient. Once inside the body the modules would assemble themselves into a larger device capable of carrying out surgical procedures. By operating from inside the body, surgeons could avoid external incisions, minimising pain and shortening recovery time for the patient.8 While many of these devices are still at the prototype stage, the Endotics System robotic colonoscope, developed by Era Endoscopy, is now commercially available. Inspired by the locomotion of the inchworm (the caterpillar of the geometer moth), it uses a series of grippers and extenders to pull itself along the bowel rather than being pushed by a doctor. This exerts less pressure onto the bowel wall, avoiding discomfort for the patient.
Coming of age
The exhibition provided a valuable insight into how medical robotics are “coming of age”, but also highlighted the challenges ahead. Professor Justin Cobb, from Imperial College London, was quoted as saying that surgery is “lagging behind” other high-tech industries. He pointed out that: “You wouldn’t dream of asking an engineer to build an engine on a lathe by hand.” Sarah Pearson added that some of the technologies showcased at the exhibition (but not all) are very expensive, so it is important that robotic innovations can demonstrate value for money: “Robots have to bring significant benefits to patients and Trusts, and they have to outweigh the start up costs, in order to be widely used. In the case of the da Vinci robot, for example, where the surgeon sits at a console, robots may enable surgeons to perform more comfortably and therefore for longer.” Explaining the aims of the exhibition, she concluded: “We wanted to demonstrate how medical robots are being used to help patients both now and the future, in all different areas of healthcare – from surgery and patient care, to diagnosis and investigation. “Robots are very good at specific tasks – they are excellent at precise, repetitive and small scale movements and they can operate in positions that would be uncomfortable or tiring for humans, but they are not good at decision making. Robots simply expand on the skills that the surgeons already have – improving dexterity and visualisation of the surgical field; removing tremor from the surgeon’s hands and enabling operations to be performed on a much smaller scale. “The main message we wanted to get across was that they are really just intelligent tools – they are not the autonomous robots of science fiction. They are here to help the surgeon – not to replace them in the operating theatre.”
• The exhibition was funded by the Frances and Augustus Newman Foundation.
References
1 www3.imperial.ac.uk/ mechatronicsinmedicine/ research/theprobot 2 Cobb et al. J. Bone Joint Surg [Br] 2006;88-B:188-97 3 www.acrobot.co.uk/ About%20Acrobot.html www.acrobot.co.uk/Sculptor.html 4 www.freehandsurgeon.com/about.php 5 www3.imperial.ac.uk/ mechatronicsinmedicine/ research/thebloodbot 6 www.toumaz.com/public/ page.php?page=sensium_intro 7 www.vector-project.com/project/ index.html 8 www.ares-nest.org/tiki-index.php