The heart is an electromechanical organ: Simply put, electrical signals cause the heart muscle to contract, pumping blood throughout the body. Technical breakthroughs in imaging modalities have led to an explosion in the quality and quantity of data on cardiac mechanics, says Pengcheng Shi, director of RIT's Ph.D. program in computing and information sciences.
More work is needed on imaging the electrophysiological aspects of the heart, says Shi, and that's a focus of the computational biomedicine research team in RIT's B. Thomas Golisano College of Computing and Information Sciences. The team, which includes Ph.D. students, postdoctoral researchers, and faculty, has published extensively and received recognition from groups including the Medical Image Computing and Computer Assisted Intervention Society (MICCAI) and Computing in Cardiology (CinC). Team members also collaborate regularly with researchers around the globe.
For example, GCCIS assistant professor Linwei Wang, GCCIS associate professor Huafeng Liu, and Shi have collaborated on work involving aspects of transmural electrophysiological imaging (TEPI) with researchers at Johns Hopkins, University of Rochester Medical Center, the Chinese Academy of Sciences, Dalhousie University in Nova Scotia, and the French national computer science research organization INRIA.
One promising development of the team's work is in mapping myocardial scar tissue deep inside the heart—a common cause of arrhythmia that can lead to fatal heart attacks when the scarring blocks electrical signals and causes the heart to beat too fast, too slowly, or erratically. Physicians are exploring non-surgical treatments for reducing scar tissue, but efforts have been hindered because of the difficulty in accurately mapping the scarred area. Using the method of transmural electrophysiogical imaging with noninvasive information from EKG and MRI, the researchers have had improved outcomes in studies using pig hearts. One tremendous advantage of the imaging technologies is that they are noninvasive and, therefore, less risky for the patient than procedures involving the insertion of a catheter into the heart.
"This has the potential to become a great screening tool for physicians," says Shi, who started heart-imaging research work as a doctoral student at Yale in 1990. When he began, his focus was on imaging the motion of the heart, which was not well understood at that time. But over the succeeding years, Shi says he has become increasingly interested in "personalized computational medicine"—developing biomedical uses for computer science technology.
"I was working with a physician who said, 'You don't understand my problem,'" Shi says. "I realized we are just being technical nerds. We were doing great work in imaging, but it wasn't what the doctors needed."
RIT, with its tradition of applied technology, can be a center for such "use-inspired research," Shi believes. "We want to do real, fundamental research on real problems."
There is growing worldwide interest in the area of computational biomedicine research, says Shi. That means more competition for research funding, but it also means there's more chance for discoveries that could benefit humanity.
In the area of cardiac disease, Shi feels that revolutionary advances in treatment are possible.
"The technology is highly advanced. We need to do more work with physicians.
"I think we are at the cusp. A little nudge—that's all we need."
Elizabeth Cherry, assistant professor in the School of Mathematical Sciences, has pursued her interest in studying the electrophysiology of the heart through mathematical modeling for more than a decade. She began the work as a doctoral student in computer science at Duke University, and later as a researcher at Cornell's department of biomedical sciences. She's continued the work since she joined the faculty at RIT in 2010.
"It just captured my interest," she says. "I find it really rewarding."
In October 2012, Cherry received a three-year grant from the National Science Foundation for a project titled "Intramural Forecasting of Cardio- electrical Dynamics." Matthew Hoffman, assistant professor of mathematics, is co-principal investigator, and Flavio Fenton, associate professor in the School of Physics at Georgia Tech, is also collaborating.
The researchers hope the project will better illustrate mechanisms underlying cardiac arrhythmias, which result from the disruption of normal electrical wave propagation in the heart. They aim to demonstrate the effectiveness of state estimation techniques for studying cardiac electrical dynamics and other 3D systems where little or no depth information is available.
"The heart has inner and outer surfaces," explains Cherry, "and it's possible to get information about what's happening on these surfaces. But it's difficult to get data from inside the tissue. We hope to adapt forecasting methods—like those used in weather— to generate more accurate models of the electrical waves in the heart."
In addition to the potential to advance treatment for cardiac arrhythmias, the work could also have uses in a variety of fields where three-dimensional observations are difficult to obtain, including understanding the spread of brain cancer and the dynamics of the ocean.
Cherry and Fenton are also part of an international group of researchers who have developed a low-energy alter- native to controlling arrhythmias such as fibrillation. Their findings were published in the journal Nature in July 2011.
The work involved applying a series of electrical pulses, rather than a single large shock, to make the heart's state more synchronous. The results of mathematical modeling as well as in vitro experiments proved promising, Cherry says.
"It does appear to work with much lower energy than conventional defibrillation." This is significant, considering that defibrillation is the primary treatment for ventricular fibrillation, the most deadly form of arrhythmia.
At RIT, Cherry is enlisting students, including undergraduates, in the research efforts. Students can contribute in a variety of ways, she says, including developing and writing computer code to solve mathematical equations describing cardiac cells and tissue, analyzing simulated and experimental data, and contributing to a highly informative website she and Fenton created, TheVirtualHeart.org.
"It's easy to pump blood," says Steven Day, associate professor of mechanical engineering. "It's hard to pump blood without destroying it."
That's one reason why it has been so difficult to produce a mechanical device to replace the heart function. However, progress toward that goal is being made.
Day has been applying his expertise in fluid mechanics to this area of research for more than a decade, beginning as a doctoral candidate at the University of Virginia. He has continued working with collaborators at the Utah Artificial Heart Institute at the University of Utah on development of a magnetically levitated left ventricular assist device, which uses magnetic bearings instead of mechanical bearings.
A ventricular assist device (VAD) is a mechanical pump that supports heart function and blood flow in people with weakened hearts. VADs can be used on a temporary basis before and after various types of heart surgery, in patients awaiting heart transplants, or longer term for some patients who are not candidates for a transplant.
Results of the University of Utah project have been promising. "We had reached the animal-studies stage," says Day, noting that the cost to continue is about $1 million per year. "Now, we're trying to figure out what to do next, to submit a new proposal to the National Institutes of Health or a foundation, or find commercial sponsorship. We haven't given up."
Meanwhile, at RIT two teams of students are working with Day as part of the Kate Gleason College of Engineering's multidisciplinary senior design program. The current projects focus on wireless power and cable connectors for heart pumps.
"Over the past few years we've done six or more senior design projects related to the blood pump," Day says. More than 60 students have been involved in design projects or as co-ops or on master's degree thesis projects.
Day also collaborates with the University of Rochester Cardiovascular Engineering Lab (www.urmc.rochester.edu/labs/Cardiovascular-Engineering-Lab/), which brings RIT researchers and students together with UR physicians including Karl Q. Schwarz, professor of medicine and director of the Echo- cardiography Laboratory and Mobile Cardiovascular Imaging Service at the UR Medical Center.
Schwarz has sponsored several heart-related research projects over the past decade. Students built an artificial heart simulator device to use as a tool for cardiovascular research—for example, to test the performance of artificial heart valves.
"For me, in terms of access to technology, it's like a candy store here," says Schwarz of Day's lab in RIT's mechanical engineering department, where he is a frequent visitor. "The RIT students are very goal-oriented, task-oriented. We're getting some good research done and forwarding the education of students. It benefits everyone."