Robotic technology is inhancing surgery through improved precision, stability, and dexterity. In image-guided procedures, robots use magnetic resonance and computed tomography image data to guide instruments to the treatment site. This requires new algorithms and user interfaces for planning procedures; it also requires sensors for registering the patient's anatomy with the preoperative image data. Minimally invasive procedures use remotely contolled robots that allow the surgeon to work inside the patient's body without making large incisions. Specialized mechanical designs and sensing technologies are needed to maximize dexterity under these access constraints. Robots have applications in many surgical specialties.

 

The idea of robotics in surgery got its start in the military. The idea was to develop technology where a surgeon could perfomr an operation from a remote location on an injured soldier in the battlefield. This concept has evolved into robotics to enhance surgical performance. In this instance, a robotic arm called Endowrist perfomrs the procedure with the surgeon guiding the robotic arm from a location in or adjacent to the operating room. The surgeon sits at a station peering at a monitor that shows a mgnified view of the surgical field. A computer mimics and enhances his hand movements. The computer in this instance makes the movements more precise by dampening even a tiny tremor in the surgeon's hands, which might increase the difficulty in performing procedures under high power microscopic magnification.

 

In 1985, a robot, the PUMA 560, was used to place a needle for a brain biopsy using CT guidance.The first surgical robots were modified industrial ones used in the late 1980's for neurosurgery to hold instruments for stereotactic biopsies. IBM then produced an industrial robot to ream out the proximal femur of a dog for the femoral component of a prosthetic hip implant resulting in greater prosthetic surface area in contact with bone. At the same time Imperial College in London devised a robot for transurethral resections of hyperplastic prostates (Probot), which was the first robot to be used on humans.

 

Robots are also used to help in performing tasks, which are either boring or fatiguing for humans. This idea formed the basis to develop Aesop, a voice-activated robotic arm that holds the camera and endoscope assembly for the surgeon during an endoscopic procedure. Not only does this reduce the need for a person to be required to do this task, but in most instances Aesop does a better job by moving precisely where the surgeon commands the robot, providing a rock-steady image and never fatiguing. To do all this, the surgeon must first make a voice card of all the commands so that the robot can recognize the command with minimal chane of error in interpretation of the voice signal. Once this is one the surgeon must repeat the command in a similar speaking voice. If the surgeon's voice raises or becomes angry, the robot usually stops responding. Hermes, or Voice Activated Operating Room, allows the surgeon to command adjustments in the camera such as light intensity, raising and lowering the operating table, turning power sources on and off and even making an outside phone call when consultation is needed. In the very near future it is expected that the patients' diagnostic studies such as MRI and CAT scans will be transmitted to a flat panel monitor in the operating room for the surgeon to review during the procedure.

 

Minimally invasive spine surgery has recently been advanced with the use of endoscopes, improvements in camera equipment and advances in medical robotics. The advantages to the patient are less pain, smaller incisions, fewer complications and a more rapid return to normal activity when compared to conventional surgery. Surgeons are now able to remove a ruptured disc using a small endoscope, repair a painful disc using electro thrermal energy and fuse a painful degenerated disc with the aid of a miniature camera and incisions no larger than 1/2 inch. Robotics and computers are now playing an expanding role in assisting the surgeon in these minimally invasive procedures.

 

Examples of such procedures now being performed that were extremely difficult if not impossible before this technology are fallopian tube repair in women, microsurgery on the fetus, and minimally invasive coronary bypass surgery. The Zeus robot made by Computer Motion and a similar device, the Endowrist made by Intuitive Surgical are now in clinical trials for the above-mentioned procedures. Even with the robot to enhance the surgeon's ability, a great deal of practice is required to master the technique.

 

Computers are also being used in image guidance systems to give the surgeon real time images and allow him to navigate to the specific location on the spine. The surgeon can use digital information obtained before surgery such as MRI or CT scans or use real time fluoroscopic x-rays to develop a three diminsional image of the spine with the exact location of a probe placed on the spine. This technology has been shown to minimize errors in placement of pedicle screws that are sometimes used to fi the spine. It is also expected that this technology will expand to allow more precise targeting of the problem with minimal incisions and fewer surgical complications.

 

The use of robotics and computers in minimally invasive spine surgery has resulted in more accurate surgical procedures, shortened operative time and fewer complications. It is expected that Computer Enhanced Image Guidance Systems will improve the precision of these procedures as a result of real time 3-D imaging at the time of the surgery.  Diagnostic studies will be digitally transmitted to the operating room and projected to monitors to further aid the surgeon in performing the correct procedure with minimal trauma to the patient.

 

Surgical robots can be classified into active or passive. A passive robot would be used to position a fixture appropriately and then be switched off, to be followed by the surgeon inserting his instruments. An example of this would be a robot to help position a device for guiding neurosurgical biopsy needles. By contrast, an active robot would actually move the tools. These include laparoscopic camera holders, telemanipulators, and robots used for burring out tissue, such as the Probot for prostatectomies and Robodoc for hip prostheses.

 

Applications

 

Robotic technology is finding its way into diverse surgical procedures, both revising the way current procedures are executed and enabling new procedures.

 

Cardiac Surgery

 

Endoscopic coronary artery bypass surgery and mitral valve replacement have been performed. Totally closed chest, endoscopic mitral valve surgeries are being performed now with the robot.

 

Gastrointestinal Surgery

 

Multiple types of procedures have performed with either the Zeus or da Vinci robot systems, including bariatric surgery.

 

Gynecology

 

Robotic surgery in gynecology is one of the fastest growing fields of robotic surgery. This includes the use of the da Vinci surgical system in benign gynecology and gynecologic oncology. Robotic surgery can be used to treat fibroids, abnormal periods, endometriosis, ovarian tumore, pelvic prolapse, and female cancers. Using the robotic system, gynecologists can perform hysterectomies, myomectomies, and lymph node biopsies. The need for large abdominal incisions is virtually eliminated.

 

Neurosurgery

 

Several systems for stereotactic interventions are currently on the market. MD Robotic's NeuroArm is the world's first MRI-compatible surgical robot.

Image-guided robots can biopsy brain lesions with minimal damage to adjacent tissue.

 

Orthopeadics

 

The ROBODOC system was released in 1992 by the Integrated Surgical Systems, INC. Robots are routinely used to shape the femur to precisely fit prosthetic hip joint replacements. Orthopaedic applications that have received the greatest attention are hip and knee replacement and spinal fusion; additional work is under way in a variety of other areas, including craniofacial reconstruction and fracture treatment.

 

Pediatrics

 

Surgical robotics has been used in many types of pediatric surgical procedures including:tracheoesophageal fistual repair, cholecystectomy, nissen fundoplication, margagni hernia repair, kasai portoenterostomy, congenital hernia repair, and others. On January 17,2002, surgeons at Children's Hospital of Michigan in Detroit performed the nation's first advanced computer-assisted robot-enhanced surgical procedure at a children's hospital.

 

Radiosurgery

 

The Cyberknife Robotic Radiosurgery System uses image-guidance and computer controlled robotics to treat tumors throughout the body by delivering multiple beams of high-energy radiation to the turmor from virtually any directions.

 

Urology

 

The da Vinci robot is commonly used to remove the prostate gland for cancer, repair obstructed kidneys, repair bladder abnormalities and remove diseased kidneys. New minimally invasive robotic devices using steerable fleixible needles are currently being developed for use in prostate brachytherapy.

 

 

 

The advantage of telemanipulation in minimising the trauma of surgery could be extended by the possibility of operating through natural orifices, leading to a true non-invasive surgery. An example of this is the Singapore Inch-Worm, a device that autonomously crawls around your colon and inspects it internally, promising the ability to perform operations from within the lumen of the bowel.

 

Improvements in visual and motor synchronisation of telemanipulators will ensure that surgery can be performed on the beating heart. The robot arms will move relative to the variable beats of the heart, so that the image that is fed to the surgeon is still, consequently eliminating cardiopulmonary bypass.

 

Limitations with current equipment is they are expensive to obtain, maintain and operate. If one of the older model non-autonomous robots is being used, surgeons and staff need special training. There are many limitations to the application of robotics to surgery. Currently, the mechanical design of manipulators limits deterity, particularly for minimally invasive procedures with severe size constraints. There is considerable room for improved kinematic configurations, as well as more compact and effecient actuator and transmission technologies. In terms of sensing and conrol, robots are controlled by computers and thus share many of their all-too-familiar shortcomings, especially for autonomous operation. Robots follow instructions literally, are unable to integrate diverse sources of information, and cannot use qualitative reasoning or exercise meaningful judgement. Although complex 3-D imaging information can be preproccessed to allow execution of very precise tasks, robots have a limited abiltiy to use information from disparate sensors to control behaviour during the course of a procedure. Increasing computational power may improve robot control capabalities, but the resulting complexity makes it increasingly difficult to program and debug these systems.

 

As scientists seek to improve the versality and utility of robotics in surgery, some are attempting to miniaturize the robots. Scientist at Hebrew University have also developed a miniature robot to navigate through the bloodstream.