Subtle clues that can save lives

When someone’s admitted to the hospital with chest pain, doctors want to know whether a heart attack is the cause, and if not, whether one may be on its way.

In such cases, they often enter a catheter into the patient’s body through the leg to monitor the bloodstream–a guide to the heart’s health. But mechanical engineering’s Kamm is working on a system that could collect even more information yet wouldn’t require breaking the skin.

Kamm came to MIT as a graduate student in the 1970s planning to become an automotive engineer. Interactions with bioengineering pioneers Forbes Dewey and Ascher Shapiro changed his mind. “So many fascinating problems seem to arise in this field,” he explains.

One of Kamm’s interests is the pulse. Most of us think of the pulse as simply an indicator of how fast the heart’s beating. But just as a wily mariner can tell a lot about conditions out at sea by observing waves near shore, the right pulse monitoring system can reveal much about the health of the heart.

“The heart’s contractility,” Kamm notes as an example, “is related to how fast the pressure rises with each heartbeat.” So if a monitor revealed a drop-off in that rate of increase, you’d know the heart wasn’t contracting as it should.

But getting solid information about the heart from a monitor placed on the skin is a tough challenge. To meet it, Kamm has created a computer model of the cardiovascular system.

The model, described in papers laden with mathematical formulas, reflects the recognition that the heart and blood vessels form a highly complex system: The arteries, for example, can change shape, or alter the chemistry of the blood flowing past.

Kamm’s model seems to have captured key aspects of the system. Its results closely match those of studies of how heart changes affect the pulse in actual patients. “The next thing is to see how our system performs in a hospital unit where the parameters of concern are being measured invasively,” he says, “so we can compare them with our model’s predictions.”

Heart-attack victims aren’t the only potential beneficiaries. With the aid of monitors that look like rings or wristwatches, the system could keep tabs on the health of all kinds of heart patients–a possibility that pleases Kamm.

“One thing that drew me to biomedical engineering,” he notes, “is the idea of applying my skills in ways that lead to real social benefit.”

by Richard Anthony « Previous | Next »

On Topic: health science+technology