Withings’ new Body Cardio scale is supposed to be able to measure pulse wave velocity, an indicator of arterial stiffness.
Any idea how they do it? You could calculate the pulse wave velocity using a user’s height and the exact timing between each heart beat’s peak in the ECG and the moment the pulse is detected in their feet. But can you get a reliable ECG signal from the feet?
Their data sheet (PDF) says it uses a combination of ballistocardiography (BCG) and impedance plethysmography (IPG) to measure pulse wave velocity
So basically, it uses a combination of electrical signal (ECG) and body recoil.
See also Medicine: Measuring the Heart’s Kick (Time)
Hi –
Cool – thanks – my withings is partly broken – so this may be an excuse to replace it.
Just read the “Science Behind” sounds quite interesting if it works.
The data sheet talks only about aortic arterial stiffness. I wonder if it takes into account conditions like aortic aneurysm (enlargement) where presumably the flow would be slower and mimic a healthy condition?
I’m curious about whether anybody is using this. I’ll post in QS Twitter with a link here.
So, apparently Withings has run into some issues with its Pulse Wave Velocity feature with the FDA and is disabling it on all Withings Cardio Scales effective immediately 
https://support.health.nokia.com/hc/en-us/articles/360000004227
That sucks because I have been using this feature regularly and have actually improved my scores over the past few months using after incorporating some adaptogens.
Thank you for the update, Bob. What sort of adaptogens did you use?
I hadn’t heard of that term. It seems that it’s a substance that helps with resistance to biological stress. Is that an accurate definition?
Yes, the term “adaptogen” covers a broad range of herbs that work with the body (stabilize/bring back into balance) and are known for their anti-stress benefits. Ones that I respond well to are chaga mushrooms (I make batches of chaga tea as well as use a tincture), ashwagandha, and reishi mushrooms.
