Virtual leaps for medicine A Rockville company, HT Medical Systems Inc., is developing virtual reality training systems that could dramatically alter how doctors perform some of the most complex surgical procedures.


Laid back and soft-spoken, Greg Merrill doesn't seem the sort of fellow who'd turn a whole industry upside down.

But the 33-year-old Merrill, whose passions lean to racing Porsches and the latest electronic gadgets, is at the forefront of a revolution that could dramatically alter how medical students and doctors train and practice procedures ranging from a common catheterization to complex heart and brain surgery.

Indeed, experts say, the technology that Merrill's company, HT Medical Systems Inc. of Rockville, is developing -- virtual reality training systems -- has moved that revolution a step forward from the nascent state in which it's been locked for years.

Some of the hurdles HT's young team of computer scientists, engineers and computer graphics experts have been faced with overcoming: the sometimes disorienting limitations of virtual reality technology, computer microchip capabilities that are costly or don't measure up and the difficulty of replicating the way human tissue and organs feel and respond when prodded, poked and pierced.

In the VR world, that attribute is called "haptic response," and it's one of the Holy Grails of moving the technology forward to a point where medical schools, doctors and medical-device manufacturers fully embrace VR as a teaching, training and marketing tool, experts say.

Today, thanks to advancements in haptic technology and powerful new computer graphics programs that don't cost their weight in gold, HT Medical and a smattering of other companies are marketing a first generation of VR training systems.

By just about everyone's account, the technology and the industry are still in a genesis state. How big the market for these systems will be is a matter of debate among experts.

Some believe that it will soon blossom into a commercial niche that rings up sales eclipsing $100 million a year, and altering medicine in much the same way that robotics has changed manufacturing.

But others argue that the market isn't yet commercially viable, that it could be many years before the technology advances to a state where medicine views VR and robotic training devices as a complement to or replacement for the traditional mentor-assistant teaching method.

"This is really a new market that's just beginning to come into its own," said Steve Hosier, vice president for corporate finance at Miller Johnson & Kuehn Inc., a Minneapolis-based investment bank that raised money for HT last year in a private placement transaction.

"It's anybody's guess how big it will be," Hosier said. "But when you consider all of the potential applications for the technology and the global need, it's easily a couple-of-hundred-million-dollar market."

Dr. Gerald Higgins is vice president for the Center for Information-Enhanced Medicine (CieMed) Global Enterprises, a commercial joint venture between the Johns Hopkins University in Baltimore and the National University of Singapore, and a leading surgical simulation expert.

A difficult road ahead

He thinks the medical simulator industry has a difficult road ahead.

"I'm one of the biggest believers in this technology, but right now there's really only a small market for it," Higgins said.

The emerging industry, he said, faces difficult technological hurdles and the fact that no medical associations or boards have plans to require VR simulation training as a requirement for certification.

Also, Higgins said, for medicine to see advantages in simulation technology for training, a set of standards must be established to measure users' performance.

For now, the industry includes just a few privately owned companies.

These include HT Medical; Eagle Simulations/MedSim Inc. headquartered in Fort Lauderdale Fla.; and Boston Dynamics in Cambridge, Mass. Eagle markets a simulator for anesthesiology training. The $200,000 Patient Simulator device is based on a sensor-loaded mannequin that mimics heart and breathing sounds, and traumatic physiological events, such as hemorrhagic shock.

Merrill, a psycho-biology major who launched HT in 1987 right out of college with his brother Jonathan, then a medical student, is bullish on the promise of medical simulator technology that blends robotics, which provides the tactile sensations, and computer imaging, which replicates how the body's complex internal wiring and plumbing look.

"We think we can leverage this technology across a lot of different medical procedures," Merrill said.

Merrill and his team at HT have targeted three segments of the market for VR technology: training for medical professionals, practicing minimally invasive surgical procedures, and showing how new devices are to be properly used for marketing and training efforts.

The initial focus for the privately held company: develop simulators for endoscopic, endovascular, and intravenous procedures for these broad markets.

For now, HT, which employs 50 people, has one VR training device on the market, a simulator for training nurses, paramedics and other medical professionals how to correctly perform intravenous catheterizations. Named CathSim, the device is co-marketed with medical supplies giant Beckton-Dickinson & Co.

The computer-based system, which sells to educational institutions for about $8,200, includes a catheter needle which students practice inserting into a boxy device that responds like skin and vein tissue being pierced. On the computer screen, the student can watch a graphical picture of how deep into the skin and vein they have gone. If the student pierces the simulator incorrectly, a voice yelps "ouch" over computer speakers.

The computer offers several different patient models to practice the procedure on, including a healthy man, an elderly women, and an AIDS patient. Each simulates varying degrees of haptic response.

The computer tracks how well the patient performs so a record of their progress mastering catheterization can be reviewed.

In medical schools and training facilities, students generally learn how to perform the procedure either practicing on fruit, plastic human hand and arm models, or on each other and patients, said Dr. Joseph Tasto, HT's director of medical research and development.

"One of the distinct advantages of virtual reality training systems is that they eliminate the jitters or 'fear' factor that overcomes a lot of students the first couple of times they actually have to do this on a patient," said Tasto.

"They can make mistakes and there's no serious consequence. That allows them to focus on mastering the motor and thinking skills needed to do it right."

HT is set to begin marketing in late January its second device, a simulator to train medical residents in a tricky procedure known as bronchoscopy, which involves threading a flexible fiber-optic tube through a patient's nose and throat and into the lungs to look for signs of cancer or to retrieve samples for a biopsy.

The company expects the device to sell for about $30,000, and to market the device with a leading endoscopy devices manufacturer, said Merrill.

HT hopes to parlay the technology behind the device into an array of training systems aimed at similar minimally invasive endoscopic procedures, said Tasto.

The endoscopy simulator includes the same type of fiber-optic tube that physicians use to perform the actual procedure. Trainees stand over an elevated bench-like device fitted at one end with a human-face mannequin. Inside the bench are a series of sensors that detect where the tube is and transmit that information to a nearby computer screen in the same fashion as a clinical setting.

As the tube is threaded through the nose and into the throat, a picture on the computer screen shows a realistic image of a fleshy red and pink throat canal. As the tube goes deeper, an image of a pulsing larynx appears and sensors trigger a coughing sound and image.

The device, said Tasto, aims to replicate the sights, sounds and difficulties physicians encounter during the procedure and tracks how well they perform and respond.

Also in development at HT: a simulator to allow heart surgeons to practice using a heart catheter to implant a new type of pacemaker developed by medical devices giant Medtronics Inc. HT developed the simulator at the request of Medtronics.

James H. Anderson, a radiologist and deputy director of the new Engineering Research Center in Computer-Integrated Surgical Systems and Technology at Johns Hopkins, believes that one of the most significant markets for simulators will be for those that allow physicians to either practice using new medical devices, or which allow surgeons to practice and prepare for surgical and other procedures on a patient specific basis.

Conceivably, he said, a patient's X-ray, MRI and other medical data would be downloaded into a simulator, providing the

physician with the opportunity for a trial run of the procedure the day before the actual operation.

The ideal simulator would replicate serious complications that could arise based on individual patient medical data, giving the physician time to consider in advance how to respond to such scenarios.

"I think virtual reality training will be quite commonly used for training in the future," said Russell H. Taylor, director of the engineering research center at Hopkins.

NTC He believes that during the next 20 years surgical simulators could change health care much as robotics has affected manufacturing.

"These systems will lead to critical advances both in the quality of surgical treatment and cost-effectiveness," Taylor said.

Corsortium of experts

The Engineering Research Center, launched in September with a $13 million grant from the National Science Foundation, is made up of a consortium of university experts from Hopkins and its school of medicine, MIT in Boston and Carnegie Mellon University and Shadyside Hospital in Pittsburgh. Its aim: help the industry overcome some of the technical hurdles and develop commercially viable simulators.

Indeed, the lion's share of the work being done in the surgical simulator field can be found among researchers at medical schools and universities, Anderson said.

The center has several systems in development, including one, dubbed the daVinci, in which radiologists could practice a threading a catheter through the groin and up into the heart. Also, the center is attempting to develop a simulator for neurosurgeons to plan and practice complicated deep brain surgery.

Physicians and surgeons, said Anderson, "must see these devices as useful and pretty realistic, otherwise they just won't be accepted." For now, designing such realism into medical simulators is a tall order.

For example, said Meiyappan Solaiyappan, a computer engineer at the Hopkins research center, the number of computer pixel images that had to be created to replicate the brain for the neurosurgery simulator are about the same as the number of images created to replicate an entire landscape used for flight simulators.

Engineers also must design systems that respond at the same speed encountered during surgery and other medical procedures: 1/1,000th of a second.

Said Anderson, "At first these VR systems will be seen in medicine as a luxury. And then they will become a dependency for a lot of doctors. It's only a matter of time."

Pub Date: 12/27/98

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