“Stealth device” could transform hidden heart condition monitoring

Cardiac Insight founder and UW Medicine cardiologist Dr. David Linker

Cardiac Insight founder and UW Medicine cardiologist Dr. David Linker

By Sandy Marvinney

A University of Washington spinoff company, Cardiac Insight, has set its sights on improving screening for one of the most common forms of irregular heartbeat — atrial fibrillation (a-fib). This condition affects about 2.2 million people in the U.S. and causes an estimated 50,000 to 70,000 strokes a year. A-fib is a challenge to detect during routine physicals because patients may not have symptoms and the arrhythmic heartbeat occurs sporadically.

The core technology is a diagnostic “smart” chip enclosed in a band-aid size strip a patient wears on the skin over the heart. It weighs less than a quarter of an ounce and can record heart rhythms for seven days.

“I called it the stealth device because it essentially disappears for the patient,” says its inventor, UW Medicine cardiologist Dr. David Linker (pictured left). This advantage inspired the product name — Stealth Ambulatory Monitor. C4C’s early support for the concept and guidance at key steps of the commercialization pathway are now bearing promise for both commercial success and public health benefit.

Most patients being monitored for A-fib wear a Holter monitor, a 3- to 6-ounce belt unit about the size of a pack of cards, with wires leading up to electrodes taped on the chest. It can be uncomfortable and records for just 24 to 48 hours. The downloaded data must be sent to a desktop computer and read by a technician, a time-consuming and expensive process. Frustrated with the limitations and cost, Linker searched for software to automatically monitor A-fib, but found nothing that satisfied him.

“I started playing around with an algorithm, tested it, and realized it could identify A-fib as well or better than anything out there,” Linker said.

He disclosed his innovation to C4C in 2004, and staff helped file a patent application for a concept drawing of a device for atrial fibrillation detection (AFD). Technology manager Laura Dorsey began working with Linker in 2005 and introduced him to local entrepreneurs and device design companies.

Monitor for the 21st century
Linker’s automated algorithm offered a huge advantage over existing technology: data analysis could be done on a microchip, eliminating the need for a desktop computer and technician evaluation.

“That means a very small, inexpensive monitoring device can permit more affordable and widespread screening,” Linker said. “I talked to various companies about licensing, but I learned that it’s myth that if you build a better mousetrap, the world will beat a path to your door. There is a lot of inertia in the business world.”

The 'stealth device' weighs less than a quarter of an ounce and can record heart rhythms for seven days.

Linker decided to design his own hardware. Dorsey helped him secure $50,000 in technology innovation funding from C4C, and $30,000 from the Washington Research Foundation, which kept the project alive at a critical time. A matchbook size device he designed in 2006 met the specifications of every existing, much larger detection product on the market. His next question: “How small can I make this?”

Very. His current prototype is an all-in-one device with a tiny flexible circuit board, memory chip, batteries, electrodes, a protective covering strip, and little gel pads for electrical contact on the skin. The smart chip’s algorithm analyzes the data as it is being recorded. When the patient returns to the physician’s office, the data is transferred to a computer and the physician can print out an instant diagnosis, plus the backup data.

Cardiac Insight spins out, secures backing
In 2008 Linker established a company with assistance from C4C staff and Brad Harlow, a technology entrepreneur in Seattle’s biomedical community. In late 2010 the company secured $200,000 in funding from WINGS angel investors, a local nonprofit group that provides early-stage investments for medical technology companies. Tom Clement, another Seattle serial entrepreneur and one-time director of the New Ventures unit at C4C, signed on as CEO to get Cardiac Insight up and running. WINGS investors provided an additional investment of $700,000 in late 2011, and another $500,000 in late 2012. Linker also secured a $150,000 Life Sciences Discovery Fund grant and will test the 7-day version of the device on 150 subjects enrolled in a large King County chronic disease monitoring study.

Linker has continued to refine and adapt his algorithm, and patents have been granted in the U.S. and Europe. With assistance of C4C patent officer Jessica Meyer, applications for the more advanced AFD3 and AFD4 algorithms are now pending and another application was filed in May 2013.

“Jessica has an excellent depth of knowledge and grasp on patent strategy, and has been a tremendous help,” Linker says.

Leadership expansion
In late 2012, Clement turned the CEO reins over to Harlow (pictured, below left, with Linker). In February 2013, Harlow submitted the first FDA 510K application for market clearance for a basic device that records electrocardiography data. Clearance was granted in May 2013.

Brad and Linker

“We recently expanded the management team by bringing on two biomedical industry executives who bring a wealth of experience in the cardiac device industry,” Harlow said. “Bill Willis, founder and CEO of iRhythm Technologies, is now our president and our COO is Robert Odell, who most recently held a similar position at Cardiac Sciences, Inc.”

The company has closed on over $700,000 of Series B financing (toward a goal of $1 million) to complete the 7-day body-worn ECG monitor and algorithm through a second FDA filing. Willis is looking for strategic funding (either as an acquisition or distribution) and Odell heads up the technology, regulatory, and production side. In the first quarter of 2014, they hope to win regulatory approval for use of the device with the data analysis algorithm and then launch preliminary commercial efforts.

“I joined the company because the device is unique and will have a real advantage over anything now on the market. Plus, all the members of the team have great reputations and track records for success,” says Willis.

At the May 2013 scientific meeting of the Heart Rhythm Society, Linker presented the results of a study comparing the performance of his automated algorithm against a standard commercial monitoring service. Analysis of 170 archived 24-hour Holter recordings by an independent electrophysiologist confirmed that his algorithm did not miss any clinically significant cases of A-fib and that recordings classified as “no AF” do not require expensive technician review.

“My colleagues in the field love the concept,” Linker says. “They want it now and ask, ‘When can I have it?’” In addition to screening for atrial fibrillation, the device can also replace most monitoring devices for other heart rhythms, further lowering cost and improving patient comfort.

If the expected time line holds, within about a year the Stealth monitor might quietly begin reducing disability and death caused by strokes from undiagnosed atrial fibrillation.