Withings' new scale can measure your cardiovascular health

Withings, recently bought by Nokia for $191m, has launched a new scale that can measure body mass index (BMI), body composition, and cardiovascular health. By measuring the speed at which blood circulates the body, or pulse wave velocity (PWV), a user can monitor and detect any health risks, shown either on the scale or a smartphone app, and seek medical help if necessary. The Body Cardio is available at Apple stores and costs $180.

Nokia recently bought Withings for $191 million and immediately put it in charge of its entire digital health business. The Finnish company may have been persuaded in part by the Body Cardio, Withings' new flagship scale that launched today. On top of measuring your body mass index (BMI) and composition, it can judge your cardiovascular health by measuring how quickly blood pumps through your body. "It's the most advanced product we've ever made and the product that most represents Withings' DNA," co-founder Eric Carreel tells Engadget.

I had a look at the Body Cardio at Withings' French headquarters, and the minimalist, Apple-esque design (created in conjunction with Paris design studio Elium), is certainly striking. The scale is just 0.7 inches (18 mm) thick, and has a flat base with no feet. That allows it to work on any surface, whether it be a carpet or hardwood floor. You only need to charge the internal battery every year or so, and using it is a simple matter of standing on the scale.

From there, you can read your stats off the accompanying smartphone app or on the scale directly. As before, you can see -- and track over time -- your weight, BMI, body composition (including fat, muscle, water and bone mass), and standing heart rate. The key new measurement, however, is the "pulse wave velocity" (PWV), or speed at which blood circulates in your body.

Withings says the pulse wave velocity gives you a snapshot of your heart health. If you have an overly fast PWV and therefore "stiff" arteries, it means you could be at risk for hypertension or cardiovascular incidents. If your blood flow speed is slower, it generally indicates more flexible arteries and good health.

So how can a scale discern all that just from your feet? It measures a very subtle change in weight that happens when you're aortic valve opens, according to the company. The scale also has embedded electrodes, allowing it deduce when the blood arrives to your feet. By measuring the time it takes for the blood to go from your heart to your feet, and knowing your height, it can calculate the PWV.

While the scale doesn't measure your blood pressure per se, Carreel says the PWV is a better gauge of heart health. "This blood velocity measurement normally requires an expensive device [called a sphygmometer) that only cardiologists usually have, and now it's available to anyone as a household device." Withings says the BodyCardio scale measurements provide a "good correlation" with medical-grade sphygmometers based on testing at two French hospitals. (The company says it will release the results of its study on Friday at the European Society of Hypertension's Paris meetup.)

As a result, Carreel believes the scale goes beyond personal fitness monitoring and into medical health territory. "Simply by standing on the scale every morning, I can track the evolution and the average value of my PWV, which is going to represent in the long-term, my cardiovascular health. So [the product can] detect these signs and warn me of any health risk, and advise me to see a doctor if necessary."

In addition, Withings will anonymously collect health data from users (provided they consent) to refine its data analysis. It will then share it with researchers, hospitals and cardiologists to see how PWV influences cardiovascular risk factors on a large scale. "We seek to understand all of the factors that influence the changes in arterial rigidity and blood flow speed (PWV), whether they be nutrition or whatever. So the question is, how can we positively influence these factors?"

Such data and research will no doubt form a big part of Nokia's newborn health business. As with Apple's HealthKit, the idea is to get data from millions of users into the hands of doctors and researchers, who can see how it relates to future health problems. That means you'll theoretically get, on top of the usual fitness stats like heartbeat and body fat composition, something more valuable as you age: A decent idea as to whether you're at risk for serious cardiovascular problems.

The Body Cardio is now available at Apple and Withings stores in black and white for $180, and will arrive to other retailers by July 7th. A cheaper version without the PWV measurement, the Body, is available at a variety of retailers for $130.