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This Fitness Wristband Wants to Play Doctor

Startup Quanttus is developing a device that monitors heart rate, respiration, and blood pressure from your wrist.
February 19, 2014

Plenty of fitness tracking gadgets and related apps can tell you how many steps you’ve taken today or roughly how many calories you’ve burned. Getting deeper insights, such as how your body is recovering from yesterday’s workout, is much trickier.

A startup called Quanttus, based in Cambridge, Massachusetts, hopes to offer such insights with a smart-watch-like gadget that continuously tracks heart rate, respiration, and blood pressure, which are difficult to measure accurately with a wrist-worn device. The plan is to use this data to offer information and even predictions about your health. This involves not only collecting a large amount of data but also applying algorithms to make sense of that data. The hope is that the gadget could help people monitor existing illnesses or show them how their work habits affect their health.

“We’re building, basically, a hardware platform; a wearable that sits on your wrist,” says Quanttus cofounder and CEO Shahid Azim. “But then there’s an equally large effort around how to make sense, how to generate insights from this data.”

The technology behind Quanttus comes from the Microsystem Technology Labs at MIT; the device, which is in the early prototype phase, doesn’t yet have a release date, price, or even a name. But since September, the company has been running validation studies at Massachusetts General Hospital and Brigham and Women’s Hospital in Boston, comparing the prototype’s measurements of the three vital signs against measurements taken with traditional  tools. Azim says the early results are “very promising” and the company is likely to offer a beta version of its product to developers this year so they can begin building apps for it.

The prototype being used in the trials looks like a digital watch with no face. There’s a square circuit board topped with components (a battery and a glowing green LED are most easily recognizable) within a frosted enclosure held in place by four screws. It’s centered on a wide, black, rubbery-looking watch band.

The device will eventually include a display that can give immediate feedback, showing data such as resting heart rate or calories burned. It will send data to your smartphone via Bluetooth so it can go to a remote Quanttus service for analysis before deeper insights are fed back to the phone. This is similar to the way the Nike Fuelband and Jawbone Up work, although Quanttus claims it can do the tracking part much more accurately than existing wearable gadgets, whose metrics often vary from device to device even when used simultaneously (see “Fitness Trackers Still Need to Work Out Kinks”). The company believes this will allow it to glean more nuanced, accurate details of your health.

The wristband tracks vital signs primarily via ballistocardiogram, which measures tiny movements of the body caused by the pumping of the heart—something Azim says sheds light on the overall performance of your cardiac system, but that is hard to measure accurately with an unobtrusive wearable gadget. An optical sensor on the wristband’s back shines light onto your wrist and measures selective light absorption as a means of determining your heart rate, while an accelerometer measures the tiny body movements that result. Respiration and blood pressure signals are extracted from this data.

Steve Jungmann, who leads the company’s product management, says the device could also work with your smartphone so that it could take into account external factors that might affect your body, such as weather, location, and pollen count.

Jungmann says a triathlete might use the device when she wakes up to see if she’s ready to go on a run or swim or if she needs to back off for a while. This could be determined by combining heart-rate variability and other metrics into a sort of recovery score. For the average person, he says, the Quanttus device could give feedback like “We see that you’re sleeping poorly. Here are things that have led up to you sleeping poorly over a number of different nights.”

The company’s remote analyses will rely, in part, on machine learning. But that is still far off. Jungmann is still using a test device that collects data on a removable memory card, which he hands off to Quanttus scientists for review and discussion. He also keeps a log of his daily activities in a smartphone app that can by matched up with the data he collects from his body. And even if Quanttus eventually proves helpful, the company’s wrist-worn measurements will likely not be as reliable as clinical vital-sign measurements.

Emil Jovanov, an associate professor at the University of Alabama in Huntsville who studies continuous physiological monitoring, says a problem with less invasive vital-sign monitoring is the “noise” that results when the person wearing the monitor is moving, making signal readings unreliable.

And Santosh Kumar, an associate professor at the University of Memphis whose research also includes continuous monitoring of vital signs, says it is “extremely hard” to measure clinically accurate vital signs on the wrist because of its distance from the heart. “Is it going to be helpful for hobbies? Yes. Is it going to be clinically useful? That is what’s difficult,” he says.

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