The stethoscope meets the digital age

Lub-dub. Lub-dub.

That's the sound of a healthy heart.

Lub-dub-dub. Lub-dub-dub.

That's the sound of one about to fail.

It's called a gallop rhythm, and like so many other sounds of heart trouble, it's virtually inaudible to the unaided human ear.

Aid came in 1816 when French doctor Rene Laennec took some paper, rolled it tightly, and placed one end of the tube against a patient's chest.

The stethoscope was born.

Now, nearing its bicentennial, it's doing things Laennec couldn't have imagined.

Minnesota-based 3M sells one of the most advanced stethoscopes: the Littmann 3200.

It's built for telemedicine.

With the right software and an Internet connection, a doctor with a 3200 can listen live to another 3200 being used on a patient far away, making it a tool for treating people in remote or hostile places, like prisons.

"One of our big customers is the California Department of Corrections," says Tim Chismar, a Littmann team engineer. "We've pretty much gone to the ends of the world and back and been able to demonstrate that we can do this."

Actually, they've gone beyond; in 2011 a doctor on Earth used a Littmann setup to hear the heartbeat of an astronaut on the International Space Station.

But Michael Barrett, a Lehigh Valley cardiologist, says a full cardiac workup can't be done over the Internet. "You still have to put your finger on the patient's pulse. You have to put your hand on the patient's chest so you can feel the heart beat."

Barrett is a fan of stethoscopes such as 3M's, though. He has used one for 10 years and recommends that the cardiac fellows he teaches get one, because soon "all cardiologists will have one."

Unlike traditional stethoscopes, which channel sound waves caused by body vibrations through tubing and into earpieces, electronic 'scopes convert heart sounds to an electrical signal that can be amplified and refined. That yields louder, clearer heart sounds than traditional 'scopes.

But it also amplifies noise. The key, 3M's Chismar says, is to home in on the heart sounds clinicians want while avoiding noise they don't.

3M does this in part by using an ambient-noise reduction system similar to that in costly headphones.

"These stethoscopes are a real advance in clarifying and amplifying sound," Barrett said. But if a doctor can't recognize sounds such as a heart murmur, "the very best stethoscope in the world is not going to teach you."

Enter Dr. Raj Kapoor, president of Wexford, Pa.-based Rijuven.

He says his flagship product, CardioSleeve, automatically diagnoses heart sounds, including murmurs.

The 1.7-ounce, wireless device is slated to hit the market in March, and will sell for about $450.

CardioSleeve attaches to any stethoscope to assess heart health pretty much anywhere, Kapoor says.

It uses algorithms to detect gallops and murmurs, and measures the heart's electrical activity by performing an EKG to identify arrhythmias and heart attacks, he says.

Instant results, plus recordings of heart sounds, are stored in the cloud for access on a smartphone.

For millions of people in developing nations, "this is a revolution," he says.

But the rise of new technology can come at a cost, says Dr. Salvatore Mangione, who teaches physical diagnosis at Thomas Jefferson University. He says relying on new tools can erode doctors' core diagnostic skills.

While telemedicine is booming, in-person visits surely aren't going away. Subrata Roy, who teaches engineering at the University of Florida, wants to make those visits safer for patients. He wants to kill the bad bugs - E. coli, MRSA, C. difficile - that may be crawling over your doctor's stethoscope.

More than a million infections are acquired annually in U.S. health facilities; germy stethoscopes are part of the problem.

Autoclaving, which sterilizes medical tools with steam, can damage stethoscopes, and it can be too time-consuming to do after every use.

He and two others have a patent under review for a stethoscope that sterilizes itself.

"I work with plasma," he says. Not the kind in your blood; the charged particles in your flat-screen TV.

When the stethoscope is on, the plasma generates warmth and bacteria-damaging gas that kills bugs.

The process takes from two to 20 minutes, can be done between patients, and, unlike autoclaving, is safe for stethoscopes, he says.

He hopes to have a prototype within a year. By then, stethoscope technology will have advanced.

But Dr. Mangione, of Jefferson, says the critical part of the process can't be bought or patented. "What I teach med students is that what really matters is not what they put on their ears, but what they have between the ears."