Anyone use a Qinux Vitalfit smartwatch?

[Richard F]

Hello all,

I'm using omnipod 5 + freestyle libre 2+ in HCL and would continue to use this system for dosing.
How do these watches measure BG levels and how accurate are they? Thinking it could be a useful reference day to day rather than opening up the app in the PDM, when working I'm often gloved, wet and muddy.

 

[Lucyr]

The watches are not accurate, I wouldn’t waste your money.

 

[Docb]

The watches that claim to measure blood glucose (apparently by magic) are useless.

However, it is possible to get a smartwatch to display the blood glucose reading from your libre providing your watch and phone are compatible. I don't know the inns and outs of it but I am sure somebody who knows will be along to explain.

 

[Richard F]

Yes suspect you're both correct, I'm still interested how they do it though.

Problem with Omnipod 5 and Libre freestyle 2+ (HCL) is there's currently no phone app in the UK, its run through a PDM controller.

 

[Bruce Stephens]

Yes suspect you're both correct, I'm still interested how they do it though.

There's a YouTube channel which has reviewed some of these things (there's a few that are pretty cheap), comparing them against DexCom. It seems they just produce graphs that are kind of appropriate for people without diabetes, so maybe influenced a bit by time of day and maybe by exercise, but of no value to someone with any kind of diabetes.

 

[Bruce Stephens]

Problem with Omnipod 5 and Libre freestyle 2+ (HCL) is there's currently no phone app in the UK, its run through a PDM controller.

Yes, if you just use Libre 2+ there's a few ways to get the results onto a phone, but when it's in a loop (or any kind of connection with a pump) then quite possibly not.

 

[SimonP]

It's very unlikely that any of the cheap devices which purport to measure BG via PPG (i.e. photoplethysmography - the flashing lights on the back of sports watches) actually do anything at all aside from guessing based on time of day.

PPG has been shown to work reliably for heart rate and blood oxygen level. Blood pressure is also possible (and there is a physiological reason to expect the waveform shape to change with blood pressure) and available on a few devices, but not many. BG is one where there isn't really a physiological reason to expect a particular change in the waveform shape, but still one might expect it to make some difference, the question is what, how detectable it is, and how repeatable it is across time for a given person and across a population.

There has also been quite a lot of research done in the past, and the "book" below is an interesting read regarding the attempts to date to achieve non-invasive BG measurement (not just using PPG): https://www.nivglucose.com/The Pursuit of Noninvasive Glucose 9th Edition.pdf

There is still quite a bit of research in the PPG for BG space, however, given the lack of a commercially available and validated sensor to date, it's likely that the techniques investigated in the research papers which continue to come out are not sufficiently robust/applicable to the general populace. Here is e.g. one which has some nice illustrations of what they are trying to measure: https://pmc.ncbi.nlm.nih.gov/articles/PMC10057625/

Many nowadays use neural nets, which make them very dependant on the sample populations and quantity of training and validation data, as well as making it very hard/impossible to determine quite what features of the waveform they are homing in on.

I do still live in hope that there might indeed be some facet of PPG waveforms that correlates well with BG on an individual basis (i.e. would need to be tuned/calibrated for an individual, rather than being generally applicable), but it remains to be seen.

I have purchased a bangle.js2 with which I can capture and process PPG data, it's now (just) a question of finding the time to do so as well as trawling through the vast set of literature to pull out techniques to try 🙂

 

[everydayupsanddowns]

Yes unfortunately those “sounds too good to be true” watch devices are unregulated and not worth wasting your money on

Maybe one day someone will make it work, but the only way to get sensor glucose on a watch as it stands is to have some software that can get it directly from the sensor you are wearing, or a cloud upload of it.

 

[Richard F]

It's very unlikely that any of the cheap devices which purport to measure BG via PPG (i.e. photoplethysmography - the flashing lights on the back of sports watches) actually do anything at all aside from guessing based on time of day.

PPG has been shown to work reliably for heart rate and blood oxygen level. Blood pressure is also possible (and there is a physiological reason to expect the waveform shape to change with blood pressure) and available on a few devices, but not many. BG is one where there isn't really a physiological reason to expect a particular change in the waveform shape, but still one might expect it to make some difference, the question is what, how detectable it is, and how repeatable it is across time for a given person and across a population.

There has also been quite a lot of research done in the past, and the "book" below is an interesting read regarding the attempts to date to achieve non-invasive BG measurement (not just using PPG): https://www.nivglucose.com/The Pursuit of Noninvasive Glucose 9th Edition.pdf

There is still quite a bit of research in the PPG for BG space, however, given the lack of a commercially available and validated sensor to date, it's likely that the techniques investigated in the research papers which continue to come out are not sufficiently robust/applicable to the general populace. Here is e.g. one which has some nice illustrations of what they are trying to measure: https://pmc.ncbi.nlm.nih.gov/articles/PMC10057625/

Many nowadays use neural nets, which make them very dependant on the sample populations and quantity of training and validation data, as well as making it very hard/impossible to determine quite what features of the waveform they are homing in on.

I do still live in hope that there might indeed be some facet of PPG waveforms that correlates well with BG on an individual basis (i.e. would need to be tuned/calibrated for an individual, rather than being generally applicable), but it remains to be seen.

I have purchased a bangle.js2 with which I can capture and process PPG data, it's now (just) a question of finding the time to do so as well as trawling through the vast set of literature to pull out techniques to try 🙂

Thank you for such a comprehensive reply.
(albeit I've googled PPGs to try to understand, useful tech)