The Ultimate Quantified-Self Device Already Exists: A Defibrillator

Heart patients already have the holy grail of the quantified-self movement running inside of them. If only they had access to the data.

The wearables industry is booming, but no one has yet come up with the killer product: an unobtrusive, comfortable device that measures a wide range of health data, from activity levels and heart rates to blood pressure and sleep patterns. While quantified-self nuts wait for this killer product, one segment of the population–heart failure patients that have implantable cardiac defibrillators (ICDs)–already has just such a device available to tap into. If only they had the data. Even though implantable cardiac defibrillators have the capability of measuring everything described above and more, only doctors have access to the information held inside.


At the University of Southern California’s annual Body Computing Conference, a group of presenters offered up a different vision. Their app, dubbed Latitude Heart Coach, gives heart patients access to all of their valuable data in an easy to understand format.

A collaboration between Karten Design, Boston Scientific, and the USC Center for Body Computing, the app turns an ICD into “a hub that collects metrics to allow patients to better manage their disease,” according to Dr. Leslie Saxon, founder of the USC Center for Body Computing and chief cardiologist at the Keck School of Medicine.

The app uses three methods to help heart patients manage their wellness: health alerts, coaching, and progressive disclosure. For example, in one algorithm Saxon developed, the combination of a weight gain of over two pounds, a heart rate increase, and a median respiratory rate increase will alert a patient that they need to see a doctor for possible atrial fibrillation. In another, patients that have had arrhythmia in the past get a notification when they have a weight increase, blood pressure decrease, and activity decrease.

Patients have access to a wealth of data on the app, but they don’t have to use all of it. One patient may only be interested in tracking his activity level and calories burned (and getting related coaching from the app), while another might only care about their heart rate trends–and that’s fine. In a patient test of the app, at least one coaching feature resonated with each respondent. “They were interested in internalizing responsibility, and making the connections between food, exercise, medication, and emotion,” says Stuart Karten of Karten Design.

In case patients don’t want to take on the responsibility alone, Heart Coach has a companion app so friends and family can receive alerts if something is wrong.

Saxon believes that ICDs are a huge opportunity for patients to take control of their health. “You’re talking about a device in someone’s body up to 10 years. Unlike with wearable sensors, data from this thing is so fantastic and accurate that you can really create some very important feedbacks for the patient that are incredible,” she says.


Heart Coach was created as an academic demonstration project, so there are no immediate plans to put it into production. But Saxon and Karten are hopeful that it will be commercialized soon. “Most companies who make devices like this are trying to figure out a safe way to provide data to patients,” says Saxon.

About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more.