Listen to the Sound of Your Heart (Pump)

Whether itís an industrial pump, a nuclear submarine pump or a pump that helps a weakened or diseased heart, all these man-made devices have one thing in common: their components make the same types of sounds.

This finding, the result of field of study known as acoustic signature analysis, is important because it may help doctors determine if an implanted heart assist pump is beginning to degrade. Heart assist pumps are used for patients who need a heart transplant. This pump aids the patientís failing heart until a suitable heart donor can be found.

"There have been instances where pumps have failed and patients have died," says William A. Smith, D. Eng., of the Cleveland Clinic Lerner Research Institute, who along with colleagues at Foster-Miller Technologies (FMT), Albany, New York, established the finding. "Surgeons have been frustrated that they were caught unaware of these impending failures. Blood pumps are still new in clinical use and there isnít always a good way to diagnose developing problems with the pump."

When they first began to be employed to help manage patients with severe heart disease, says Dr. Smith, "pumps were only being used for a few weeks, so mechanical wear was not an issue. Today, more patients are getting pumps for two or three years so mechanical failure can occur."

Failure rates are low, but the consequences are serious. In collaboration with FMT, Dr. Smith is developing a diagnostic tool that would allow physicians to monitor the mechanical performance of a heart assist pump. Foster-Miller, considered a leading expert in acoustic signature analysis, has developed very sensitive diagnostic tools to monitor performance of pumps at power plants and in nuclear submarines.

"Many industries that use pumps have the same problem we have in the medical field with heart assist pumps; they canít afford to wait until a pump breaks down to fix it," says Dr. Smith. "They have to know weeks or sometimes months in advance that a pump is going bad so that they can be prepared to make repairs or replace the pumps."

In acoustic signature analysis, experts listen to a pumpís moving parts, each of which produces a distinct sound, or acoustic "signature."

"A ball bearing, for example, has a specific hum, and that hum will change before the bearing actually stops working," says Dr. Smith. "So an expert can tell when the bearing needs to be replaced. We are transferring that technology to heart assist pumps."

Foster-Miller is currently developing a prototype that will use very sensitive microphones and sophisticated computer algorithms to break down the sounds transmitted by heart pumps. By using a mathematical model, acoustic signature analysis will be able to determine if the bearings, motor, valves and other components of the pump are normal or showing signs of wear. This is expected to give physicians data that will warn them when a pump is failing.

"If we can show that the pump is not operating optimallyóthat it is on the verge of failingósurgeons can operate and fix it. Thus they could help those patients sooner," says Dr. Smith.

Source: Cleveland Clinic Magazine, Summer 2004

 

This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional health information, please contact the Center for Consumer Health Information at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771. If you prefer, you may visit www.clevelandclinic.org/health/ or www.clevelandclinicflorida.org. This document was last reviewed on: 9/1/2004

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