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Stanford Report, October 22, 2003

Engineers, medical scholars team up to create new technologies to fight disease

BY AMY ADAMS

When medicine and engineering mix, the result is a host of devices for diagnosing, treating or monitoring disease. Through various Bio-X Interdisciplinary Initiative projects, such devices are in the works for a range of medical applications -- some of which may be available to doctors within the next few years.

Scanning brain activity

One such device under development as part of a Bio-X collaboration combines two existing technologies for monitoring brain activity. The resulting tool will give a more accurate glimpse into the brain's activity, said Dr. Vinod Menon, an associate professor of psychiatry and behavioral sciences, who heads the project with radiology Professor Gary Glover.

Menon said that two commonly used tools for scanning the brain, called fMRI and EEG, each have weaknesses. fMRI, or functional magnetic resonance imaging, pinpoints which brain region is active, but the detection lags behind real time. EEG, or electroencephalogram, detects exactly when brain waves change but can't locate where in the brain the signal originates. By combining the two into one tool, researchers can see precisely when specific brain regions become active in response to noises, images or mental events.

Menon said this tool could be useful for researchers trying to better understand the brain, and could help neurosurgeons locate and remove brain regions responsible for triggering an epileptic seizure. "It could be used to look at memory, learning or even sleep in real time," Menon said.

So far, the team has shown that the two types of data can be recorded simultaneously and successfully integrated using complex computer algorithms. When the device has been fully tested, they expect it to be a resource for other Stanford researchers studying brain function and dysfunction.

Surgical training

A quite different Bio-X project focuses on educating medical students rather than diagnosing patients. A technology being developed by Kenneth Salisbury, a professor of computer science and of surgery, teaches medical students how to perform surgery before testing their skills on real people. This tool, a collaboration between computer scientists, engineers and surgeons, should be available to medical students within the next few years, said Christopher Sewell, a graduate student working with Salisbury.

The system includes a computer monitor with images of the surgery and two handheld mock surgical tools that provide resistance similar to that met by scalpels and tweezers. When the computer image shows the scalpel near tissues the device becomes more resistant, mimicking the process of making an incision. Additional sounds representing operating room monitors give information about the computerized patient's status.

In the demonstration version of the system, a student cuts into an organ of a virtual patient, removes a tumor and stitches the tissue back together. Like any real patient, the computerized image bleeds or even dies if the surgeon-in-training isn't careful.

Sewell said that although similar devices exist for helping students get comfortable with surgical tools, this one includes a more complex scenario with events that can change depending on what steps the student takes during surgery. Sewell will present a poster on the surgical emulation at the Biomedical Computation at Stanford Symposium on Oct. 25. The symposium will be held in the Teaching Center of the Science and Engineering Quad.

Clear vision

Other devices in development through Bio-X grants help repair tissue that is damaged through the wear and tear of normal life. Dr. Christopher Ta, an assistant professor of ophthalmology, leads one project that could help the roughly 10 million people worldwide waiting for a cornea transplant to treat their cloudy vision.

Dr. Christopher Ta, an assistant professor of ophthalmology, is leading a Bio-X project that could one day help the roughly 10 million people worldwide who need a cornea transplant to treat cloudy vision. “Our goal is to develop an artificial cornea that we can use in place of a transplanted human cornea,” Ta said. Photo: L.A. Cicero

The cornea is a clear membrane that covers and protects the eye. With age, trauma, infections or disease, this covering can become opaque. The blurry vision is easily cleared with a replacement cornea, but Ta said fewer corneas are available for transplant than are currently needed. "Our goal is to develop an artificial cornea that we can use in place of a transplanted human cornea," he said.

So far, Ta's team has tested several possible materials, but none has been a perfect fit. The challenge is finding a material that is clear, strong, flexible and allows molecules to diffuse into and out of the interior of the eye. He hopes to have found this ideal material and start testing it in humans within the next five to 10 years.