Tuesday
January 18, 2005
It's a routine operation. The patient is prepped. The surgical team is ready. The surgeon steps up to the operating table and dons special headgear to take a look before beginning. What he sees is a full-color, 3-D holograph of internal organs, superimposed over an image of the patient's body."It's X-ray vision in real time," says Erik Dutson, M.D., a surgeon at the UCLA Medical Center in Los Angeles.
This virtual reality map guides the surgeon as he navigates the surgical robot with finesse around the blood vessels, nerves, organs and bones to the site of the operation. The procedure is successful--and not just because of the 3-D display and futuristic robots, but because the surgeon has practiced the procedure dozens of times on patient simulators so lifelike that they talk.
You may expect the surgeon to be Dr. Leonard H. McCoy, a.k.a., Dr. Bones, from Star Trek, but it isn't. In fact, procedures like this could be happening in your operating rooms--if not now, in the very near future. From holograms to lifelike mannequins that surgeons can program to mimic scores of OR scenarios, to robots helping perform surgical procedures, the operating room of the future will be a vastly different place from what it is today.
Patients and hospitals stand to benefit from the developments. And while hospitals' budgets for these technologies may be limited, some hospital executives say that such technology in the OR is worth the investment--if for no other reason than that patients are asking for it.
Researchers are developing an esoteric procedure called augmented-reality assisted surgery to give surgeons a 3-D view of the internal organs of the patient they're operating on. With augmented reality, surgeons see not only traditional two-dimensional CT, MRI and X-ray images, but a 3-D map that shows the surgeon everything he needs to navigate his way to the area to be operated on.
Surgeons use a conventional laparoscopic video screen for standard imaging, and a second video screen for the augmented reality images. Those images are produced by superimposing computer-generated images onto real-life images of the patient. Data from the CT or MRI scans are merged with the output of a video camera trained on the patients to give a virtual view of the procedure.
"Virtual reality takes surgery a step further and allows you to interact with and navigate through virtual 3-D reconstructions of the patient," says Dutson.
Augmented reality is still in the experimental phase, with only a handful of medical centers around the country doing active research. However, French surgeons reported in the Nov. 11 issue of the Journal of the American Medical Association that they removed a patient's cancerous adrenal gland using the procedure; they say it is the first use of augmented reality for general surgery in humans.
Augmented reality can make operations less risky and invasive, and can allow more exacting procedures. In addition, because it is computer-based, augmented reality can be used to develop simulators to model various surgical procedures exactly. Eventually, surgeons will be able to practice without putting patients at risk.
"That will be a reality in the next few years," Dutson says. "We'll be able to take actual patient data, create a holograph, and practice the procedure first before we do it on the patient."
Another form of surgical "practice" involves using patient simulators. This comes in two forms: computer-generated virtual reality simulations, and actual mannequins on which to practice.
Like airline pilots who practice their skills in sophisticated virtual reality simulators, so too surgeons are using similar technology to hone their techniques.
Leading the way to create such virtual patients is the University of Colorado's Center for Human Simulation. The surgical model is an outgrowth of the National Library of Medicine's Visible Human Project, which the agency launched to create anatomically detailed, three-dimensional views of the human body that can be used to teach medical students.
In 1993, the NLM contracted with the university to create a virtual human. An executed Texas murderer who had willed his body to science was frozen, cut into blocks and sliced into 1-millimeter sections. MRI and CT scans of the slices generated nearly 1,900 cross-section images that were digitally reassembled. The result was a computerized human rendering that can be interactively toured and manipulated.
The goal of the program is the creation of highly realistic computer simulations that can be used to practice surgical procedures, says Vic Spitzer, director of CU's Center for Human Simulation.
Indeed, Spitzer already has created a simulation model that surgeons can use to practice knee surgery. The virtual knee can be used by experienced surgeons preparing for their 600th knee surgery, or by freshly minted docs preparing for their first real patient, Spitzer says.
"They're always going to do their very first operation," Spitzer says. "But if they've already done 200 of them on a simulator, then they're far more prepared for that first patient."
In Ohio, hospitals are using patient simulators to train doctors in a wide range of medical procedures, including cardiac catheterization. Riverside Methodist Hospital (part of OhioHealth) is breaking ground on a 20,000-square-foot, $3 million virtual teaching hospital to be housed in its McConnell Heart Hospital in Columbus.
The facility will have an operating room and minimally invasive surgery training program, an intensive care unit, treatment areas, microvascular lab, laparoscopy labs and a cardiology simulator.
The project, dubbed the Center for Medical Education and Innovation, will use six patient simulators--four adults, one child and a newborn--manufactured by Medical Education Technologies Inc., Sarasota, Fla. The virtual patients, which cost about $185,000 each, mimic the human body, with heartbeats, reactive eyes and chests that rise and fall as they breathe. The mannequins--"Don't call them dummies," says Lou Oberndorf, CEO of METI--are programmed with 70,000 responses, including adverse reactions to medications, cardiac arrests and convulsions.
"Our goal is to teach procedures and crises in an operating room setting," Oberndorf says. "Now you can actually create a real-life situation in which you have a crisis in the OR and you get all the correct indications physiologically." And because they're highly sophisticated computers, the mannequins can capture not only the procedures but physician responses, as well. That means students will be able to learn from mistakes, and the mannequins will live to teach again.
"If we can have surgery residents up in the lab learning basic surgical skills on simulators and not learning on patients, that's going to contribute to patient safety," says Pamela Boyers, Riverside's director of medical education.
Because the use of laparoscopic surgery is growing, patient simulators also hold the potential of being used to train surgeons in the next generation of laparoscopy--robotic assisted surgery.
It has four arms and is 7 feet tall, but it's not the lovable robot from Lost in Space. It's a device called the da Vinci Surgical System, and it's designed to translate a surgeon's hand movements into rock-steady micromovements inside a patient's body.
"It's not a robot like you'd see on TV. It doesn't do anything unless the surgeon moves his hands and controls it," says David Rosa, director of marketing for Intuitive Surgical, the Sunnyvale, Calif., firm that makes the da Vinci. "It takes those hand movements and scales them to the tips of very precise instruments inside the body."
Robotic-assisted surgery accounts for a tiny portion of all procedures, but increasingly they're being used for intricate laparoscopic procedures.
The machine is approved by the Federal Drug Administration to assist in a growing number of surgical cases, including lung and esophagus surgery, prostate removal and other urological procedures, and mitral valve repairs. In July, the device was cleared for use in coronary anastomosis.
Surgeons use da Vinci by sitting at a remote console and guiding robotic arms into four small pencil-size insertions in the patient. From the laparoscopic camera, surgeons have a 3-D view of the area being operated on, magnified up to 10 times what they would see with the naked eye.
"Have you ever seen the movie Fantastic Voyage?" asks Hal Frazier, a urologist at George Washington University Medical Center, Washington, D.C. "That's what we're experiencing. We feel like we've been miniaturized and we're down inside looking up at this gigantic boulder of something, when all it is is a tiny prostate."
The surgeon "operates" from a console about 10 feet from the patient using master controls that act as her hands for the procedure. The surgeon's movements are translated into real movement by the robotic arms inside the patient, which were designed to minimize tissue damage.
Because the surgical instruments at the end of the robot's arms mimic the movement of the human wrist, surgeons can overcome the "chopsticks" feel of operating regular laparoscopic instruments. In addition to helping the surgeon reduce hand tremor and fatigue, patients benefit because there's less pain, less risk of infections, less blood loss and transfusions, less scarring and faster recoveries, proponents say.
The systems aren't without their detractors, though. Robotic-assisted surgery calls for additional physician and staff training, usually an additional staffer in the OR, and operations typically last longer than regular laparoscopic procedures. And they're expensive: $1.2 million per machine is typical, plus another $100,000 or more annually for maintenance and upgrades.
Those hurdles won't stand forever, though, Frazier says. As sophisticated as it is, he sees the da Vinci as merely a stepping stone. "It's a very rough model of what's coming in the future," Frazier says. "In five or 10 years, it's going to be a whole quantum leap in improvement. And it's still pretty darn cool even now."
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