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By: Colonel Richard M. Satava, MD FACS
Walter Reed Army Medical Center
Advanced Biomedical Technology
Advanced Research Projects Agency
Not in the past 100 years has such an upheaval in medicine occurred: The Discipline of Surgery is joining the technologic revolution and advancing the state of the art with laparoscopic surgery. This represents a radical shift in the concept of surgical practice. The "Great Leap of Faith" has occurred; for the first time in history, surgeons are performing surgical procedures without physically seeing or touching the organs they are removing or repairing. It is being done indirectly through video and remote manipulation. The impact of laparoscopic surgery has been profound and it is a product of our younger generation Nintendo(TM) surgeons, who bring their innate haptic skills from video games. We are exeriencing this revolution because we have the simultaneous emergence of the enabling technologies and the surgeons capable of exploiting this technology. While the change occurred as a marriage of two established procedures, video endoscopy and laparoscopy, the fundamental science behind both of these procedures had been used for years in business, industry and academia before being applied to surgery.
Laparoscopic surgery is simply a herald for the next generation, and it represents surgery's "wake up call" to the information age. There is finally a realization that medicine may actually be a small subset of "information with a medical flavor". Everything we need to know about a patient can be brought to the surgeon in electronic (digital) form, such as video images during surgery or teleconsultation, CT or MRI scans, laboratory data, medical record and vital signs. In addition, with the new technologies of teleoperation and telepresence surgery (see below), the surgeon can now palpate, manipulate and even operate by moving joysticks or surgical handles that send electronic signals to the end of instruments to do the task. Thus the key to the future is the digital physician, who brings information into the monitor of a surgical workstation and can act by sending electronic signals to the remote site. In essence, we can dissolve time and space, because the surgeon does not have to be physically present to "know" about the patient or to physically bring surgical expertise to bear. By looking through the rose colored glasses perspective of the digital physician, tasks previously thougt impossible are now practical. For example, by fusing a 3-D MRI (digital) image over a realtime video image (to see an brain tumor not physically visible to the human eye), the surgeon can now have "x-ray vision" and precisely determine the margins for resection. By scaling movement of the joystick so that 1 inch equals 1 micron, and filtering out muscle tremor (the same way unwanted noise is filtered from audio sounds), a surgeon can now accurately control a surgical instrument with micron precision - a feat not otherwise humanly possible. This can be achieved only through the digital interface of a surgical workstation.
The enabling technologies for this paradigm shift are the foundations of information technology: Software (medical informatics), hardware (high performance computing) and networking (the "information superhighway"). For the past 2 to 3 decades industry, federal laboratories, military and business have invested billions of dollars and built the most sophisticated infrastrucucture to empower human performance; it is now time to enhance the powers of the surgeon for an even greater quality of patient care.
This revolution was not implemented to do remote surgery but to improve upon laparoscopic surgery: the capability of remote surgery is simply an added benefit that accrues to leveraging these information and digital technologies. The intent was to return to the surgeon those facilities which were lost with laparoscopic surgery: the 3-D vision, dexterity, and sense of touch of open surgery.
The centerpiece is telepresence surgery, with the surgical workstation. The workstation contains a 3-D video display, stereophonic audio input, and hand controllers with multisensory input and dexterous manipulation. When seated at the workstation, the surgeon has the illusion of having an open surgical procedure directly in front of him. By grasping the instrument handles of the the controller the surgeon controls a remote surgical manipulator identical to the instrument in his hand, capable of performing accurate, dexterous procedures in a place distant from the surgical workstation. In this fashion, a surgeon can perform surgical procedures with all the convincing realism as if the patient were directly in front of him.
Networking will make it possible to perform these procedures in distant places. Today there are a number of larger medical institutions that routinely use satellite transmission to perform "tele-medicine" to their smaller affiliated clinics. By utilizing the "information superhighway" with telepresence surgery, multiple surgeons in different cities could participate in a single operation, or a distant superspecialist could become your first assistant. Likewise, a surgeon could operate in a dangerous or inaccessible area, such as a submarine, Antarctica, or a space station; or surgery could be performed in a third world country without the expense and time of traveling there.
Robotics could be integrated into the surgical workstation. Procedures could be planned ahead of time, and the surgeon can be assisted with extreme precision by robotics with artificial intelligence. Alternatively, a specific portion of the procedure can be set up by the surgeon and a preprogrammed robot could conduct that specific portion, a form of collaborative surgery.
In flexible endoscopy, the only active portion is the tip, and the insertion tube is used to shove the working tip through the GI tract. Instead of using a colonoscope. a micro-robot (instead of the working tip) could be inserted into the rectum and electronically controlled with a joystick from the workstation.
All these potential applications would require training. The computer science of virtual reality is one in which a simulation of any part of the anatomy like the abdomen can be recreated in 3-D computer graphics and be manipulated using a special glove instrument controller or joystick. This computer generated abdomen or "world" could then be fed into the surgical workstation and be practiced upon as if it were a real cadaver or patient. Surgical procedures could be learned and perfected by a resident before "flipping the switch" to a real patient. Soon 3-D recreations of actual patients (from MRI or CT scans) will be imported into a virtual world to both preplan and practice a patient-specific procedure before actually performing surgery. In research, experimental procedures could be tried first upon a virtual animal, before performing them upon live animals. The first generation of a virtual reality surgical simulator has already been created for the abdomen using the current standard for virtual reality: A head mounted display for vision and the Dataglove(TM) to manipulate the organs. It took nearly 40 years for the Link Flight Simulator to reach such realism that today's pilots spend as much time perfecting their skills on a simulator as in an aircraft; it is not unreasonable to expect that a surgical simulator could accomplish as much for surgical education in a much shorter period of time.
What exists today are the very first steps, such as the Green Telepresence Surgery System [Note 1] at SRI, International. Even as this central system is being developed, parallel independent projects for the framework are being explored and implemented. At University of California - Irvine, radiologists are refining input such as real time 3-D image reconstruction of CT, MRI or ultrasound scans. Virtual reality surgical simulators [Note 2] are creating "worlds" of the GI and GU tracts at High Techsplanations. Robotic hip replacement [Note 3] is in clinical trials at the University of California - Davis, and microrobots [Note 4] are scampering about on the research laboratory floors of the Massachusetts Institute of Technology. As the global telecommunication network matures, the framework can be bound together to improve the quality of patient care. Refinements like tactile feedback, true stereoscopic vision, multisensory input, and higher resolution graphics will enhance realism and strengthen the framework to completely reconfigure the Art of Medicine and the Discipline of Surgery.
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