All Heart

It’s not hard to find examples of the lifesaving power of the digital stethoscope created by Eko Health, a company co-founded by Jason Bellet, BS 14. 

Just a few hours before being interviewed for this article, in fact, Atlanta-based physician Alexis Okoh found himself helping a patient 5,500 miles away with the help of Eko’s remarkable device. A medical assistant in Ghana was examining a woman complaining of fatigue—“an easy symptom to brush off as just being old age,” explains Okoh, a non-invasive cardiologist and global health innovator. Then the assistant placed an AI-enabled Eko device on the patient’s chest. 

Within 15 seconds, Okoh heard the patient’s heart and lung sounds and saw the electrocardiogram data via Eko’s platform, which integrates with enterprise healthcare systems. He diagnosed her need for urgent care in less than three minutes, and just a few hours later, the patient was receiving lifesaving treatment in a hospital in Ghana—a country of 35 million people but fewer than 30 cardiologists.

That sort of long-distance healthcare wasn’t possible before Bellet and his Eko co-founders from Berkeley Engineering—Connor Landgraf, BS 13, MEng 14 (bioengineering), and Tyler Crouch, BS 14 (mechanical engineering)—reimagined the humble stethoscope. 

What was once just a rubber tube became, thanks to them, a smart device that could increase sound volume by up to 40 times, minimize background noise, and pair with the Eko app to generate and record sound waveforms and electrocardiograms. A name change in 2023 from Eko Devices to Eko Health reflects the company’s evolution: It now includes FDA-cleared, AI-powered algorithms to analyze data for early detection of heart and lung disease and abnormalities—all aimed at an even more audacious goal: to realize a world in which where you live doesn’t determine whether you live.

Says Bellet, “I heard at a conference recently that AI is not going to replace physicians, but it will replace physicians who don’t use AI. That’s the nuance that we’re trying to thread.” 

Today, Eko devices hang around the necks of more than 700,000 healthcare professionals across five continents and are used on tens of millions of patients every year—delivering cardiopulmonary care at a scale never before seen. The devices hold special promise for “cardiology deserts” in underserved countries and throughout the U.S., where about 22 million people live in counties—most of them rural and low income—with no cardiologist, according to a 2024 report in the Journal of the American College of Cardiology.

Bellet’s success has made him this year’s recipient of Haas’ Leading Through Innovation Award, which recognizes alumni who pioneer remarkable solutions to society’s most complex challenges.

“Receiving this award is a full-circle moment, as my earliest memories building Eko are tied to my time at Haas,” says Bellet, who serves as Eko’s chief business officer and board director. “Classmates became co-founders. Teachers became advisors. And the school became our accelerator. What started during undergrad is now an FDA-cleared platform helping millions of patients receive better care and continuing to scale globally. That kind of innovation and progress requires dedication beyond any single individual, and I’m proud to use this moment to acknowledge the co-founders, team, customers, investors, and Berkeley community who made it possible.”

Origin story

When Bellet first arrived at UC Berkeley in 2010, medical device manufacturing wasn’t on his agenda. He planned on studying political science and theater, disciplines that lean heavily on the capacity to create a vision and tell a compelling story. “Then I took an intro to business course and fell in love with that program,” Bellet says, “so I transferred to Haas where, really, I got to do a mini-MBA as an undergraduate.”  

Across campus, Landgraf was taking a senior thesis class with Professor Amy Herr on medical device development: identifying health problems, thinking through technical solutions, and appreciating the complexity of the regulatory business model. Landgraf landed on the stethoscope, used billions of times annually to check heart and lung sounds. He wondered if he could turn the 200-year-old device into “the Shazam of heart sounds.”

Like Shazam, the popular song-identification app, Landgraf thought a digital stethoscope could be a real-time database of heart sounds, helping healthcare providers conducting routine exams to accurately diagnose early signs of heart disease, like atrial fibrillation, structural murmur, and low ejection fraction (the percentage of blood leaving the heart each time it squeezes). Landgraf asked Crouch, an undergraduate engineer and self-taught software developer, to create a prototype. 

Crouch describes the initial device as a basic connector. “It was essentially this 3D-printed digital stethoscope adapter with a mobile app to see the data,” he says.

Landgraf, a former student government president, had attended campus political events coordinated by Bellet and says he respected “his gumption and organization as a student leader.” Bellet’s obvious expertise in communicating a vision would complement the engineering and strategy work already underway by Crouch and Landgraf.

“At some level, storytelling is the most essential skill to almost any innovation,” says Landgraf, “because it’s your ability to translate what’s cerebral and technical into something that’s approachable, that can spread and engage. And that’s an incredible skill set Jason brings.” 

In 2013, Landgraf pitched Eko to Bellet, then a junior, but Bellet’s senior year and next chapter were already mapped out. “I had planned on doing some student government work, then I was headed to Deloitte to do consulting,” Bellet says with a laugh. “By the middle of my senior year, helping Tyler and Connor on Eko, I knew: Eko was going to be the next chapter.”

Old soul, new technology

In 2014, investors were initially skeptical of the young trio seeking to translate their rough prototype into a manufactured device. At the time, many of the startups competing for investor attention were pitching software via apps, says Crouch. Eko, on the other hand, was making hardware, circuitry, and software in a medically regulated space. “The youngest group to have gotten the type of FDA clearance we needed for Eko was in their late 30s,” he says. 

Bellet, however, was undaunted by the challenge of sharing a convincing vision for a product in its infancy. He thanks his Haas courses, specifically Innovations in Communications and Public Relations, taught by Diane Dwyer, BS 87, for his confidence. The class pairs students with entrepreneurs to shape their companies’ PR and communications and to help solve issues using design-thinking methodology. Bellet drew on that experience to create the first news release for Eko. 

“Then we pitched it to a bunch of local media and The New York Times, and we got stories on it,” he says, recalling his astonishment.

Dwyer wasn’t surprised. An award-winning former broadcast journalist, she occasionally advises the Eko team on its PR and communications strategy. “Even at that young age, Jason had a level of patience and presence that most people don’t achieve until their 40s, if ever,” she says. “He’s an old soul developing new technologies.” 

Bellet obtained early support for Eko from Mayo Clinic’s chair of cardiovascular diseases and the chair of Stanford’s department of medicine. “Those people are busy, and they’re not going to pick up the phone for a 22-year-old kid,” Dwyer says. “But they did. Jason had persistence and was thoughtful in the way he approached people, so they wanted to help him. And they believed in what he was doing.”

The early buzz was essential to Eko’s success. “That first press coverage fed investment, which then fed more stories, and so on,” says Bellet. “I think PR, comms, and storytelling for a precommercial, premanufacturing stage is critical. Obviously, the technology has to be there, and the product has to be there. But what could have made or broken Eko early on was getting people behind the vision.”

SkyDeck support

In fall 2013, the Eko trio was given space at UC Berkeley’s SkyDeck accelerator, an opportunity that was an early catalyst for the company. In 2015, the Eko co-founders were named to Forbes’ 30 Under 30 list in healthcare, and Time magazine named the Eko CORE digital stethoscope, the first FDA-cleared stethoscope that functions as both analog and digital, as one of the 25 best inventions of the year.

“We got so much out of being part of SkyDeck,” says Bellet, “from introductions to investors to the literal office space and credibility it gave us.”

Bellet felt so strongly about the importance of SkyDeck’s support to the success of Eko Health that he signed the UC Berkeley Founders’ Pledge, which enables company founders, equity holders, or investors to make a nonbinding commitment to give back to UC Berkeley when they attain success. 

“The pledge reflects my commitment to give back to Berkeley as Eko grows,” says Bellet. “I want to honor the school that played such a critical role in our journey.”

Culture meets the moment

As time passed and the Eko team outgrew SkyDeck, it found its own office space in Berkeley. By late 2019, the company was ready to level up and leased a larger space in Oakland. But move-in day in March 2020 fell on the first day of the Bay Area COVID quarantine, and only a few critical employees would be allowed to enter, for months, while everyone else pivoted to remote work.

Crouch says Bellet’s leadership created the cohesion needed for consistency and team morale at a delicate stage in Eko’s development. “He helped the culture push through,” says Crouch, “despite how unsettling that time was.”

Bellet recalls the pandemic as the chance to demonstrate how Eko’s culture included the ability to quickly innovate. By 2020, he says, “We had a commercial product, but the demand for our product grew by 10 times overnight because we were the only stethoscope on the market that could livestream heart and lung sounds under protective gear.” 

But healthcare providers wearing full personal protective equipment and “masked up like astronauts” had a hard time putting a standard stethoscope in their ears. “Our customers needed us to adapt the product,” says Bellet.

Within four weeks, Eko crafted a version of its device without the tubing. Essentially, Bellet says, “We were able to put the stethoscope in a case, put the case onto the patient, and then Bluetooth-stream the heart sounds to the healthcare provider’s AirPods under the protective gear.”

All the while, the Eko team remained on lockdown. The company got state exemptions to operate as an essential business, and some employees worked around the clock: Warehouse workers fulfilled increased demand; manufacturing sourced aggressively from different vendors to overcome global supply chain issues.

Bellet’s ability to support a team going through an unprecedented time allowed it to grow and soar during the pandemic. “That, to me, was when Eko went from early-stage startup DNA to a real growth-stage company, very fast,” says Bellet. “We went from 20 people to 60 people in about a year and a half.”

Still, Bellet stresses that this story’s heroes aren’t the medical device manufacturers who adapted quickly: “We were one step back from the front lines of care, where the real leadership and bravery were from emergency department doctors and the folks using our products, going into COVID wards without vaccines. But to play even a small part in that was incredible.”

A long view of the future

Today, the company is based in Emeryville, Calif., and has about 100 employees. Eko continues to gain accolades for its CORE products, which include two digital stethoscopes and an attachment that transforms an analog stethoscope into a digital one. One measure of the company’s trajectory: 10 years after Eko CORE made Time’s best inventions list, the magazine put Eko Health on its list of the world’s top health tech companies of 2025. 

More importantly, peer-reviewed studies keep proving the efficacy of Eko products. In January, The Lancet published a paper showing that in patients examined with AI-enabled stethoscopes over the course of a year, detection versus standard care was more than double for heart failure, more than triple for atrial fibrillation, and almost double for heart valve disease.

Bellet’s innate patience and persistence are currently at work expanding the reach of Eko’s enterprise-level AI platform for disease detection, called SENSORA. Landgraf says Bellet is an expert at successfully explaining to buyers that innovating health systems is extremely complicated and takes time.  

“He is doggedly pursuing those relationships, refining the strategy consistently over a long period of time, keeping that North Star in mind of what Eko is trying to create and the role that it can play for those specific health systems,” he says. “And he’s had some incredible successes.”  

Where might Eko’s path lead next? Bellet says that just as the iPhone became a marketplace for applications, algorithms can be built to allow Eko devices to screen for a spectrum of cardiac and pulmonary conditions.

“We have a pipeline of about 10 diseases that we’re currently working on with pharma companies and device companies to screen,” he says. “Go out another 10 years, and there are probably 50 different diseases you can screen for using heart and lung sounds—from pneumonia to pulmonary hypertension to tuberculosis to a variety of cardiac rhythm abnormalities and super rare conditions that are hard to diagnose.” 

Bellet knows changes in healthcare can move at a frustratingly slow pace. But the constant examples of Eko products saving lives make persevering worth it. 

“To see our innovation move from idea to prototype to something now used by clinicians around the world to impact care for the better gives me a profound sense of purpose,” he says. “And to do it alongside my co-founders and a team like ours is the honor of a lifetime.”