App review: Eko Duo Stethoscope

February 26, 2019

This stethoscope and accompanying app help healthcare providers hear and see the heart in a whole new light.

Editor’s Note: Each month, physician reviewers will evaluate a particular app or category of apps that provide some functionality for medical practices and/or patients.

In 2017, I had the opportunity to review the Core stethoscope. This stethoscope from Eko Health is designed to increase a physician’s ability to understand auscultated sounds by way of providing visual waveforms for both cardiac and pulmonary sounds. I found the stethoscope to be an intriguing approach to taking traditional data and making it more useful for both point-of-care utilization and teaching purposes.

The Core quickly became my default stethoscope because of its audio and digital amplification quality as well as its ability to record waveforms. It wasn’t perfect-its main problem is a heavy digital head that kept falling off the tubing-but it was a promising start.

Read more: App review of Eko Stethoscope

Now, early adopter physicians around the country are getting their hands on the company’s latest model, the Duo. As its name suggests, the Duo focuses on two things in addition to traditional auscultation: the ability to record audio waveforms of cardiopulmonary sounds AND capture electrical activity in the form of a single-lead EKG. This is amazing and adds a whole new dimension to the traditional art of auscultation.

Jason Bellet, one of Eko Health’s co-founders and current vice president of provider solutions, told me they started the company back in 2013 at University of California, Berkeley because they wanted to develop a tool that could augment cardiopulmonary assessment. They spent a long time working with established cardiologists to understand what was needed.

Ultimately, they decided modifying the stethoscope was an ideal way to bridge the gap between traditional auscultation and data analysis and evaluation. They wanted to ensure that their device could be used in a fully digital fashion complete with excellent fidelity and also capture data in an interactive way to make the findings actionable. With the Duo, the company is one step closer to its vision of a product that can gather, analyze, and interpret traditional physical findings.

The Duo brings together multiple pieces of information. There is traditional auscultation of the heart and lungs combined with audio waveforms of the sounds, a phonocardiogram, and a single-lead EKG that, depending on chest placement, can act as different leads from a traditional 12-lead EKG.

The Duo will definitely cause providers to do a double take. At first glance, the Duo looks like a stethoscope earpiece/tube combo connected to a long silver box as opposed to the traditional bell/diaphragm combo. The box is where all the magic is housed, as it connects to stainless steel leads as well as the audio transducer. The Duo’s tubing actually screws into the box. This is a godsend modification for anyone who encountered the frustration of the original Core’s transducer, which constantly slid off the tubing because of its weight.

In practice, the Duo can fairly easily be used as a traditional stethoscope. There are some issues when using it for cardiac auscultation with women because of anatomic considerations, but a bit of careful maneuvering makes the process easier. Excessive body hair also makes it difficult to get an accurate EKG, but this was not a consistent issue. The tubing connecting the earpieces to the transducer is a little short, but any longer and the transducer’s oblong shape would probably make it awkward to carry. Last, the tubing cannot be swapped for another tube, such as with the Core, because of the proprietary connection to the transducer.

What is very convenient is that the entire transducer can be separated from the earpieces and used separately if you have a smartphone or tablet. Because the transducer houses a Bluetooth unit, it can send all data, both audio and tracings, to the device. Furthermore, it can be used in real time through your device’s speakers or attached headphones. It is actually feasible to use the transducer the majority of the time without the earpiece, as the transducer is slim and pocketable.

Rating: 4 of 5 stethoscopes

Pros: Ability to do a more thorough heart evaluation and store/send data as needed; portable and solidly built


Cons: Shorter tube, some difficulty maneuvering the transducer and some challenges with body hair for EKG capture; cost is at high-end of the stethoscope spectrum

All of this information is presented via the Eko app, available for both iOS and Android. The app is a powerful tool that allows you to make several adjustments to the device for listening purposes, including bell or diaphragm frequencies and multiple listening positions for various organs. In addition, the app gives you the ability to play back, store, and transmit both sounds and tracings in a HIPAA compliant fashion. The app itself can store recordings for multiple patients and uses additional security in the form of a passcode or Touch ID on an iOS device to protect patients’ information.

I believe my father, a cardiologist, would have appreciated the ability to take recordings at the bedside and transmit them remotely to others. Bellet says Eko Health is working with EHR platforms to make data integration easy.

Eko Health also offers a premium telemedicine service for $40 a month. This allows organizations or individuals to livestream cardiac sounds to a provider (Bellet described it as “Skype for heart and lung sounds”). The company reports they have partnered with a number of institutions and health systems that are using this feature to allow staff to remotely stream data to physicians not at the bedside, including Children’s Health in Colorado and Spectrum Health in Michigan.

In my first review, I said the Core was replacing my traditional stethoscope because of its added dimensions of utility. I’m pleased to say that the Duo is now replacing my Core. In actuality, you don’t need both. Depending on your need, either one will suffice.

They seem designed for two different markets, and the pricing reflects this. The Core runs $199-$299, depending on which model you choose. The Duo is currently not available to the general public but has a manufacturer’s suggested retail price of $349. Bellet says the Duo will soon hit the market. In the meantime, interested physicians can sign up on the company’s website to be notified when it’s available.

For many physicians, the Core will fit the bill. It provides great audio functionality, analog capability, and the ability to record heart and lung sounds. The Duo ups the ante by including a single-lead EKG functionality. For me, the Duo represents the cutting edge of bedside technology and the possibility of real telemedicine functionality. It is now my default stethoscope for everyday use.

Saroj Misra, DO is a board-certified osteopathic family physician who has served as program director of the family medicine residency at St. John Health System in Warren, Mich.