An App A Day


How personal trackers will change health care.

An App a Day Paul Lachine
An App a Day Paul Lachine

In the privacy of their own bathrooms, people can find out whether they’re pregnant or have HIV. They can even swab for DNA to unravel their ancestry. Yet it’s difficult to answer simpler questions, like “Do I have the flu?” That’s because the most advanced diagnostic device in most medicine cabinets is a thermometer. Regularly measuring and understanding anything more complex than body temperature, such as respiratory rates and heart rhythms, is a physician’s job. So patients often go to the doctor when they don’t need to or don’t go when they should. By providing doctors with better data and patients with better decision-making tools, personal health monitors and diagnostics could break that cycle.

In the last few years, medical-device manufacturers have begun using miniaturized sensors and mobile phones to gather clinical information. The AliveCor and iBGStar iPhone attachments, for example, monitor heart rhythm and blood glucose, respectively. The Tinké converts heart and respiratory rates into a stress rating. And devices that gather a broader range of metrics are on the way. The Scanadu Scout, a pocket-sized Bluetooth-enabled dongle that will be available later this year, uses several kinds of sensors, including infrared, to measure blood flow, blood oxygen, electrical heart activity, temperature, and heart rate. (The company is competing for the Tricorder X PRIZE, a competition to create the first no-contact mobile diagnostic tool.)

The sheer volume of data produced by a network of devices like the Scanadu could be a boon for public-health workers. A person who tracks one health metric every hour will generate nearly four times the amount of data in the Library of Congress in his lifetime. Spread over several metrics and many people, the data could provide a snapshot of national or local health at any given time. Epidemiologists could use that information to spot early indicators of disease and issue alerts before the infection has a chance to spread.

For individuals, personal data could be paired with software-based diagnostic tools. Patients with hypertension, for example, would be alerted to pressure spikes, which could enable them to better manage their condition with diet and exercise. Scanadu is developing apps that can analyze smartphone images of user-collected blood or urine samples and detect respiratory infections. The company plans to refine its software to synthesize a data sample, diagnose common ailments, and let patients know when they’re sick enough to need a doctor. For the first time, emergencies will be emergencies, and colds will be colds—and doctors won’t be the only people who can see the difference.

(Rebecca Boyle/PopSci)