Q&A: Cardiogram's Ballinger on using the Apple Watch to track heart rate

The Cardiogram Apple Watch app automatically shows a user's most recent heart rate and doesn't require the use of a phone camera.

Cardiogram, a heart-rate tracking app, is leveraging the wearable Apple Watch to make it easier to measure for patients with heart conditions to track their cardiovascular health without the use of a phone camera and having to manually refresh the app, which updates at least 50 times a day. The app is enabled by the Apple HealthKit and is is being used by patients with sleep apnea, atrial fibrillation, and diabetes.

Cardiogram co-founder Brandon Ballingner talks about the app, who's using it, and how the company is educating patients and healthcare providers about artificial intelligence

1. MM&M: How many users does Cardiogram currently have?

Ballinger: Currently, tens of thousands of people open Cardiogram each day. Sometimes people stereotype wearables as only for the 20-something crowd, but our median user is 40 years old. About a fifth of users are older than 50 years old, and many of them have conditions like sleep apnea, atrial fibrillation, or diabetes.

2. MM&M: How can users access Cardiogram?

Ballinger: We're currently live on iPhone with Apple Watch, but we're working on support for other devices. Eventually, we'd like to support all devices with a heart rate sensor – Android Wear, Fitbit, Garmin, Polar, Xiaomi. We think that as heart sensors become cheaper they'll also become ubiquitous.

3. MM&M: What is the accuracy rate of Cardiogram?

Ballinger: The most recent accuracy figure we got is about 87%.

4. MM&M: Tell us about your partnership with the University of California, San Francisco.

Ballinger: We're working with UCSF Cardiology to find better ways to detect atrial fibrillation, the most common abnormal heart rhythm, which causes about a quarter of strokes. Behind the scenes, we're applying a technique called deep learning, which is used by Google and others for self-driving cars, speech recognition, to translate English to French, and more.

The more data our algorithm sees, the more accurate it gets. Anybody can participate in our study, regardless of whether they have a heart condition.

5. MM&M: Are you partnering with pharmaceutical companies, medical device companies, or hospitals?

Ballinger: We're partnered with UCSF Cardiology to complete a full study. Once we have proven accurate results, then we plan to partner with all constituents in the healthcare system.

6. MM&M: How are you encouraging or educating physicians about the app? What are some of the challenges of educating physicians about the app?

Ballinger: We're working with our academic collaborators to present our work at places like the California Heart Rhythm Symposium. One challenge is that our work is inherently interdisciplinary, combining cardiology with artificial intelligence.

From a physician's perspective, they may not be aware of how much modern AI is capable of. For example, a group at Stanford University recently trained an algorithm to recognize lung cancer more accurately than expert pathologists. The reason it worked so well is that the algorithm can analyze about 10,000 different attributes of each image, compared to a few hundred for a pathologist.

Conversely, how do you explain some of the unique constraints of clinical research to artificial intelligence experts? For example, Google trains its speech recognition algorithm on about one million hand-transcribed speech snippets, but even the largest hospitals do not see a million patients.

So we invest a lot of time in figuring out how to bridge this gap. As the clinical research develops, you'll see us do that by publishing in both medical journals and AI conferences.

See also: Pharma companies turn to wearables to improve R&D

7. MM&M: What do patients say about the app?

Ballinger: We love hearing from the patients themselves. Our top request from patients is to develop more tools to help them share data with their doctors.

8. MM&M: How do you compete with other heart rate apps such as Instant Heart Rate, Cardiio, and Cardiograph?

Ballinger: Some apps do active heart rate measurement using your cell phone's camera. This is a very clever use of technology, but it has the disadvantage that it's active — most people won't hold up their finger to the camera every day. In contrast, devices like the Apple Watch can measure your heart rate passively, throughout the day, but the volume of raw data is enormous. Cardiogram helps you organize that data so that you can see whether your heart rate is spiking due to coffee, food, rush-hour traffic, or a stressful meeting.

9. MM&M: What plans does Cardiogram have for the next  five years? Will you be launching other apps or products?

Ballinger: Some people use the Tricorder from Star Trek as their North Star, but for us, our goal is to build something more like Baymax from Big Hero 6. When you use Cardiogram, you should trust in its accuracy, but more importantly, you should feel cared for.

This interview has been edited and condensed.