The First Stethoscope Was Nothing More Than Rolled Up Paper
When René Laennec leaned down to place his ear on the chests of his patients, he was uncomfortable, especially with his female clients, especially if they were overweight. Then one day he had an idea...
It was the early 1800s. No one had yet invented the stethoscope. To get the best read of the heart, doctors employed immediate auscultation.
This technique required doctors to get intimate with patients they were sometimes meeting for the first time. They had to lay their ears directly on the chest of the client, sometimes several times, against the skin.
It was invasive, and ineffective compared to what would come next. Doctors of the day didn’t have any idea how much better diagnosis could be.
Laennec solved it one day when diagnosing an overweight patient in his practice at the Necker-Enfants Malades Hospital in Paris. He had the idea to make a funnel to his ear. We'll come back to that in a second.
Thanks to Laennec’s invention in 1816, today we have a wide array of stethoscopes. Theses little funnels to the ear give doctors not only a professional distance from client’s more intimate body parts but also precision information about many aspects of the client’s health.
We would have never had easy access to these parts of the body with immediate auscultation alone. It all started with a rolled up notebook.
The simple solution discovered by Laennec was to roll up a nearby notebook. He placed one end against his patient’s chest, the other against his ear. Voilà!
What he later termed mediate auscultation, took its first shape that day. Laennec discovered that not only could he distance himself from his client’s, the rolled notebook amplified and improved the acoustics of the chest better than his ear.
Laennec later upgraded his design with wood, crafting a similar shape as the rolled notebook, but more substantial. He called his invention “the stethoscope.”
That was 1816. By 1850, doctors everywhere in the developed world used Laennec’s stethoscope to diagnose patients. What they found was that they could hear more than just the beat of the heart, but nuances in the rhythm, even the sound of the lungs expanding.
The stethoscope opened worlds of information about the internals of the body not yet discovered. In time, they learned to use it on other parts of the body, such as the intestines.
Binaural Stethoscope[caption id="attachment_6313" align="aligncenter"] Marsh's binaural stethoscope | antiquemed.com[/caption]
If Laennec’s stethoscope was to medicine what the wheel was to agriculture, the innovation of an Irish physician named Arthur Leared was like the first horse-drawn carriage.
In 1851, a good idea turned into an even better one when Leared engineered a stethoscope with a binaural arrangement. With Leared’s creation, practitioners could listen with both ears, blocking outside noise, focusing on the client’s internals.
He presented his idea at the Great Exhibition in London. There, another man, Dr. Nathan B. Marsh from the United States (Cincinnati) borrowed some inspiration.
Marsh made a binaural stethoscope that same year using India rubber, but Marsh’s design was problematic. It fell apart.
But, Marsh’s idea was further developed by another man, George Philip Cammann, a doctor from New York. Cammann’s design was the first reliable binaural stethoscope.
Cammann never patented his design, as he wished for it to be available to physicians everywhere. Had it not been for Leared, medical professionals today might still use the trumpet designed by Laennec.
The New Century[caption id="attachment_6316" align="aligncenter"] Cammann Stethoscope 1870 | phisick.com[/caption]
Cammann’s Stethoscope remained the industry standard into the 20th century. It wasn’t until 1940 when Dr. Howard B. Sprague along with his engineering collaborator, M.B. Rappaport, came out with the Rappaport-Sprague Stethoscope.
Sprague had been working on a new stethoscope since 1926, one that offered practitioners two bells for listening. One was best for respiratory listening, the other for cardiovascular.
One can still find modern versions of the Rappaport-Sprague Stethoscope, but they cumbersome, mostly novelty items.
In the 1960’s, a man named David Littmann made a lighter stethoscope with better acoustics. The brand born from his work, Littmann, would also introduce the tunable diaphragm in the late 1970s.
This innovation, which leverages advanced materials and engineering to improve the frequency spectrum heard by practitioners is the standard by which most professionals measure all other stethoscopes.
There is a good reason why the Littmann brand of stethoscopes dominates Medshop Australia’s catalog.
Today’s Stethoscopes[caption id="attachment_6319" align="aligncenter"] Littmann Electronic 3200 | littmann.com[/caption]
In the modern era, humanity has witnessed the invention of 3D-printed stethoscopes. This convenience we have thanks to Dr. Tarek Loubani back in 2015.
His 3D-printed stethoscopes aren’t impressive from a technological standpoint, but they offer remote areas of the world access to equipment and help they wouldn’t otherwise have.
As it turns out, printing a stethoscope is more affordable in many places than importing them. It’s also a fast turnaround.
A man named Richard Deslauriers invented the DRG Puretone in 1999, a stethoscope with noise reduction technology. Since then, noise reduction has become something of a standard itself, found in many non-professional audio components.
Some of today’s stethoscopes employ chip technology, marrying analog sounds with digital processing, giving practitioners a more robust image of what is going on inside a patient’s body.
As one example, the Littmann Electronic 3200 melds Bluetooth with Littmann’s own noise reduction technology. It’s 85 percent effective reducing ambient sound and can amplify what it hears by 24-times the original volume.
The future of stethoscopes is wide open, of course, but it’s easy to imagine how computers could soon use what’s measured by a stethoscope to render 3D virtual imaging. Medical professionals could to see inside a patent in real time without a scalpel, just by holding up a stethoscope.
Come what may, prospective future technologies will borrow from what we learned starting with pressing a rolled up notebook against a patient’s chest.
We owe it all to the French doctor, René Laennec.