Noninvasive, with any sort of accuracy that can be used for anything, is most likely impossible.
So back to "invasive"... what can we do... embedding a device under your skin, right around where your watch goes, that can be powered and communicate with the watch. While also making sure the device is not rejected by the body and stays in place.. AND has no other adverse side-effects. I think this is where it'll ultimately end up for the people who want it. sub 10 min procedure to put it in and should last for quite some time (maybe dissolves after 5 years for upgrades?)
Profit.
Well yes, but also substantial life saving interventions become possible.
I'd get a tattoo, but I'm not interested in anything that has to be removed
We need significantly better power sources that are either have lots of energy capacity, xor some energy capacity and able to charge while inside the body.
Either version they need to be small enough that the procedure is cheap and the body doesn't reject the device. Additionally, anything like this would need to go through regulatory bodies for medical devices, and would not be approved for "healthy people" (i.e. significantly reduced adoption).
Roughly putting us back to non-invasive.
We do it with pulse ox pretty well, but +\- 2-3% O2 sat and repositioning isnt a big deal.
Having the watch move and misreadibg blood sugar can have serious consequences.
A can of worms.
But I do applaud the team for working on the technology nonetheless.
Biasing low would be the move if scared of risky downsides.
It’s not enough of a difference to be deadly, as the sibling comment suggests, and the clinician guidance is to always eat something if you are feeling hypo, and at or near that level.
The upshot is that I set my CGM-linked pump to target 1 mmol/L higher to compensate.
And the Libre3 is so much better than anything else I've tried before.
Another T1D here with 2 decades direct experience with Medtronic, Tandem, Dexcom, and Abbott. I'm an outlier, but that doesn't make this story less empirical. I've got many years of data to prove it and while I can't match real autonomy's millions-of-points-per-second firehose, I do have years of hundreds of point-per-day.
It's n-of-1 for sure, but one way of looking at that is just that there's a lot of latency on the data gathering, particularly in emerging stories in healthcare where the entire system is weaponized against the truth reaching wide audiences, but I digress. Back to the objective facts vs. the subjective reality.
I'd just like to confirm the findings here in that it's a wicked problem, just like T1D:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7529400/
The fact that CGM or non-invasive requirements follow suit should be of little surprise to anyone.
It's challenging enough that I wore 2 CGM's concurrently over the past year: Dexcom G6 and Freestyle Libre 2. They both have poor data veracity, particularly at the times that I need them most - when fasting; that would be sleep and exercise. Both critical periods for any diabetic. I should know because the former put my T1D brother-in-law in an early grave.
I realize that some people have great success with these devices and that's something we should celebrate. However, we should not celebrate the fact that there are legitimate lawsuits against these companies. I've been outspoken about the risks given my family history, exercise, and experience working in medical devices that have a history of injuring patients:
https://en.wikipedia.org/wiki/Therac-25#Problem_description
https://www.11alive.com/article/news/investigations/the-reve...
The amount of time that I spent on the phone with Dexcom support was excessive and frequently at all hours of the night since the problem would present with alarms that cannot be disabled and are able to disable do-not-disturb mode on the smart phone and sound like an alarm system from the Austin Powers series.
That leaves the patient with two choices: tolerance (which is unrealistic at 3 AM) and powering the phone completely off, which silences it while having the side effect that alarms can't save the patient from potentially life-threatening hypoglycemia given that alarms emanating from the Tandem t:slim X2 alone are not sufficiently intense to wake me.
Dexcom has responded to this crisis by following the letter of the law: since I first reported the problem, they have replaced 2-3 dozen sensors under warranty while following the typical corporate communication playbook of not admitting design flaws or any legal culpability while not admitting the rather serious problem of the fact that, when the G6 is used in concert with a hybrid closed loop system such as the Tandem t:slim X2, inaccurate sensor readings on the low side have the potential to underdose the patient, and inaccurate sensor readings on the high side have the potential to overdose the patient. This is because near-autonomous, near-realtime basal rate adjustment is responding to sensor measurement that can often be at odds with reality and not closely monitored at times like sleep and exercise.
This isn't just theory!
I've seen both of these scenarios play out while exercising and sleeping - two events that cannot be precluded, are frighteningly difficult to handle given failures in the aforementioned design of the alarm system, and no one at either Tandem or Dexcom seems to admit, document, or address which is distressing given that these are FDA-regulated devices in markets that aren't Therac 25 but have the potential to end badly in large populations.
I've tried to alleviate the problem by wearing two different CGM sensors concurrently. I wore an Abbott Freestyle Libre 2 from spring through fall 2022 in addition to my Dexcom G6 where I have little choice given the joint venture design chosen by Tandem. That has done little to alleviate the problem since both sensors tend to move in parallel showing the same inaccurate readings in fasted states around sleep and exercise.
Worse, the only evidence I've seen that anyone in the mobile software design side of equation understands the problem is xDrip and the various people working in OpenAPS:
https://scholar.google.com/citations?user=rt1_gOgAAAAJ&hl=en...
I don't believe they are getting the attention, credit, or remuneration they deserve.
I hope that the situation does not turn out like American insulin pricing, where the first person to perish not being able to afford insulin was documented several years ago:
https://www.snopes.com/fact-check/alex-smith-died-couldnt-af...
If we think social media needs regulated, I'm pretty sure what we call healthcare in the United States qualifies for better regulation than that given FDA's lack of oversight.
In contrast, the Libre3 transmits via Bluetooth, and does so once per minute, without me having to do anything else. The non-insurance retail cost is about $70 per sensor. With insurance, it can be much lower.
For me, the size difference is a real game changer. This thing is so much easier to wear and live with.
For me, the automatic update once per minute is also a real game changer. I don't need to tap the sensor with my phone to get a reading, I just open the app on my phone and the data is already there.
By all accounts, the Dexcom G7 is about the same size, and because Dexcom plays nicer with other devices, that's the way you want to go if you're trying to close the loop on the CGM plus automatic insulin dosing.
For now, I'm super happy to have the Libre3. The app needs some improvement, but this is already a World Series + Super Bowl winner.
https://www.wareable.com/wearable-tech/movano-ceo-on-its-rf-...
Movano plans to ship an Oura-style smart ring this year, but it won’t have the glucose monitor. (One might suspect the “moonshot” glucose RF chip story is meant to keep investors excited through the zero-revenue stage until hopefully the more ordinary smart ring takes off.)
A ring form factor is too aggressive and difficult of a target.