Introducing the Next Generation of the Stethoscope

Beyond the risk of transferring bacteria, there are also inherent limitations of the stethoscope.

It's been a medical mainstay for centuries – but it's time for a change.

There is no medical instrument in history that's been used as extensively or has had the longevity of the stethoscope. Though its design is fairly basic and has remained virtually unchanged for centuries, the stethoscope can help assess an incredible array of conditions inside the human body.

Using a stethoscope properly, a trained health care provider can hear even the most subtle abnormalities in cardiac, respiratory and intestinal function. It can detect blockage and constriction in arteries and veins, and can identify issues in the pleura, the fluid-filled membranes that line the thorax and lungs. The stethoscope is also used to monitor uterine health and can detect the faint heartbeat of a baby as it develops inside the mother's womb.

But on the verge of the 200th anniversary of the stethoscope, it's time for a change. For all the stethoscope can do, its limitations and risks have never been more evident.

In an age of ever-increasing drug-resistant bacteria, the stethoscope is an often overlooked conduit for cross-contamination. Numerous studies, many at hospitals abroad, have shown that using the same stethoscope on multiple patients increases the risk of spreading bacteria such as staphylococcus aureus, methicillin-resistant staphylococcus aureus (also known as MRSA) and klebsiella pneumoniae, which can survive on inanimate objects for several months. In fact, one study found various parts of the stethoscope, like the diaphragm, tubes and ear pieces, had the same contamination levels following a patient exam as a physician's hands.

The Centers for Disease Control and Prevention recommends stethoscopes be disinfected with ethanol-based cleaners after each use. However, due to time constraints placed on health care providers today and perhaps an overall lack of appreciation for the potential danger of cross-contamination, stethoscope hygiene, in general, is not always routinely practiced.

But beyond the risk of transferring bacteria, there are also inherent limitations of the stethoscope, which I first began to contemplate during a recent exam. A patient of mine had experienced a temporary but frightening cardiac arrhythmia and was struggling to describe it to me. "I wish I could have recorded it so you could hear it, too," the patient said.

With that, I sat out to change the way we conduct exams.

With the help of a remarkable team at Orlando Health, including physicians, researchers, engineers, developers and medical students from the University of Florida College of Medicine, I led the development of the next generation of stethoscope, known as HeartBuds. It's based on the same concept as the original stethoscope, but employs smartphone technology, a downloadable app and a new listening device that may dramatically reduce the risk of infection.

As opposed to the metal end of a traditional stethoscope that's used over and over again on countless patients, the HeartBuds listening device is an individually wrapped, single-use plastic piece, slightly bigger than a quarter. After a patient exam, it can either be disposed of or, better yet, given to the patient to take with him or her for home use.

The listening device connects to a smartphone and, using a downloadable app, sounds are played through the smartphone speaker. Traditionally, only the person wearing the stethoscope can hear sounds from the exam, but with this system, both the health care provider and patient can listen to the exam and discuss it in real time. Volume control on the smartphone helps compensate for ambient noise, and there is a visual component displayed on the screen of the smartphone that corresponds to the sounds.

Perhaps most importantly, each exam can be recorded, saved and shared, which has important implications. With this technology, contact with the patient is limited. During an exam, one member of the healthcare team can record a patient's sounds and others can simply listen to that recording, instead of initiating their own exams. The recording can also be stored in the patient's electronic medical record for future reference and shared with other health care providers who may need it.

The technology is novel, but to see if it offered any tangible advantages over traditional stethoscopes, we put it to the test. At Orlando Health, we examined 50 patients, comparing the HeartBuds system to two Food and Drug Administration-approved class I and class II stethoscopes, as well as a commonly used disposable model. Disposable stethoscopes are commonly used to diminish the risk of cross-contamination.

However, our results showed that disposable model we tested missed the presence of heart murmurs in patients 43 percent of the time. It also missed carotid bruits, sounds in the neck that indicate moderate to severe blockage of the carotid artery, up to 75 percent of the time.

As expected, the class I and class II stethoscopes, which can cost up to $400 each, performed much better. But to our delight, the HeartBuds were just as effective as the expensive models at detecting heart murmurs and carotid bruits. The difference is, HeartBuds cost less than $10 each to produce, meaning we've developed a potentially safer and considerably cheaper way to perform auscultation.

Further, there are potential in-home applications for patients who require more constant monitoring, like those with heart failure or chronic obstructive pulmonary disease. Using HeartBuds, patients could record their own sounds at home, email them to their doctor to have them evaluated remotely and only make in-person visits when necessary, further reducing health care costs.

Commercially, athletes could use HeartBuds to track their conditioning, and pregnant women could record the sounds of their unborn babies to share with friends and family anywhere in the world.

Given the ubiquitous presence of smartphones, it only makes sense to employ them more consistently in medicine. Every health care provider carries a smartphone, and we need to take advantage of their technological versatility – even if that means getting rid of the stethoscopes around our necks and doing away with a medical icon after centuries of service.