Comment by blhack | Hacker News Reader

Comment by blhack | Hacker News Reader

I just wanted to say that I love this post.

There is a huge space around """fitness""" devices that are running around the FDA regulatory process. I think there is going to be a huge health revolution by making everybody take their weight, glucose, blood pressure, sleep statistics, and heart rate statistics every day and feed them into an AI.

The major techincal step forward that is happening is microneedles that can draw out interstitial fluid. The patient doesn't feel it, and you can do things like constant glucose monitoring, and constant cortisol monitoring (which is huge) completely uninvasively. It's going to be amazing.

The breakthrough device is going to be a watch that can sense glucose and cortisol all the time. A while ago there was some PG post about wanting a tricorder, well it's coming, and it's going to look like a watch.

Sidenote: if anybody reading this is working in any of the labs working with these microneedles, please contact me, I would love to collaborate with you.

If the microneedles are part of a watch and the watch is simply worn on the wrist like a normal watch, how do you avoid (1) breaking the needles, or (2) contaminating the needles with random substances that are present on the user's skin or periodically enter between the watch and the skin?

Could you replace the needles somehow? Can you avoid having to replace the needles frequently?

Every worn device that I'm aware of that continuously interacts with the body in some way is either totally noninvasive (like a pulse oximeter that just shines light through a finger, or an EEG with external electrodes placed against the skin) or invasively and persistently attached to the bloodstream or an organ system (like an IV, an insulin pump, or an implantable defibrillator).

Or do you have to somehow deliberately engage and retract the needles when putting on and taking off the watch? But wouldn't they break, or something, when the watch moves around on your wrist?

Or do you apply a disposable or partly disposable sensor under adhesive tape to one part of the body, and then have the watch receive data from it using electrical or electromagnetic signals?

The way (these) continuous glucose monitors work is that there's an adhesive patch with the needle, sensor, some storage/processing and comms module. Attaching the patch is done via a spring-loaded module and the data is read by waving the reading over the patch. The patch itself lasts a couple of weeks before it deactivates itself and you need to apply a new one.

The patch/sensor doesn't hurt going in but depending on where it's attached and how you move it can sometimes pinch a bit when you move around. And you'll definitely feel it when you jostle it.

> making everybody

That sounds extremely fucked up. No thanks. How do you suppose this will be enforced? Higher health insurance rates for people who want privacy? Or are they just going to start arresting and throwing people in prison over this? Sounds like a horrible future.

AFAIK continuous glucose monitors are regulated by the FDA because of the microneedles: breaking the skin puts them under extra scrutiny. I don't think they need to be behind a prescription, but I 100% support regulation to at least ensure that the devices are safe and sterile.

You need FDA approval (510(k) or PMA) if you use the device to make an actual medical claim, regardless of whether it pierces the skin or not.

Good point. It might have been that a prescription is required because it pierces the skin; at any rate I remember some complication on getting a hold of them easily because of that.

They are medical devices that provide diagnostic information so they would require licensing regardless. The tongue depressor is a class 1 medical device.

In the case of a CGM like Dexcom or attached meter like Freestyle Libre or a glucose meter that takes a drop of blood on a strip, or even glucose monitoring urine strips: all require FDA approval to be marketed as a diagnostic tool. They have to show a certain tolerance of accuracy and be manufactured under GMP. The FDA isn't messing around.

I've been down this path with the FDA in a prior life so I'm not just speculating.

(Also FWIW the extremely thin needles used in the mounted devices aren't referred to as "microneedles" -- that term is used for a different technology used in some drug delivery patches.)

This sounds a lot like a Theranos idea, here is why.

There are physical constraints concerning continuous glucose monitoring, you cannot simply replace the capillary blood with something drawn from skin tissues depth. It significantly lags the real blood glucose level and the water content screws up the measurement. Even the continuous glucose monitors that are implanted under the skin and that are significantly larger than anything a watch would do have issues with precision and lag compared to the blood prick method. It is worth it because of the better control loop, but its not a simple topic.

Continuous glucose monitors are not significantly larger than a watch. See pictures here https://www.dexcom.com/g6-cgm-system and here https://www.freestylelibre.us/

They are also more precise than it sounds like you think they are. I think that all current models require some calibration every once in a way (maybe every few days).

Also, there is a lag, but it is fairly predictable and for a lot of potential use cases the lag is not an issue.

Continuous glucose (and lactate and maybe cortisol) monitors are not like Theranos.

The folks making the "cardiogram" app were somehow able to figure out which of the users had diabetes simply by monitoring pulse. This was part of a study they did with an academic institution (UCSF? -- can't remember) and not a feature they advertise. This isn't the same as figuring out BG level but is quite interesting nonetheless.

I work in a field adjacent to healthcare, and we're spending a lot of time at the moment making sure we're not regulated as medical device software.

What you've just described will be one of the most regulated devices known to man in every jurisdiction I can think of including the US, Canada, UK, EU and Australia.

> I think there is going to be a huge health revolution ...

How would any of what you listed help against cancer, aging and the obesity crisis?

It won't. Simple as that. Our environment, food, and meds are the primary instigators in biological deregulation.

And you can potentially track that biological deregulation and measure the effectiveness of interventions and the harm of certain environments/habits through the use of monitoring. It's not as simple as you state.

changes in vital signs will only happen generally during an acute process

Yes it will. I’ve talked with many people who simply don’t know how their body reacts to certain foods (glycemic response). Having that data, and seeing what a milkshake does to your body is huge.

Having more continuous data on the metabolome throughout someones life could potentially tell us some interesting things about cancer, aging, and obesity.

We already know, for instance, a bit about the beginnings of glucose dysregulation in the beginning of diabetes. If we could have more samples of "continous" glucose data from a person, then we could catch glucose dysregulation before it becomes either type 2 or type 1 diabetes (or something else). We'd thus be able to more easily keep someone at risk from getting type 2 diabetes through simple lifestyle interventions (which would be a lot easier to study with a lot of continuous glucose data) or if it is type 1 we could administer the BCG vaccine to keep them from losing their pancreatic function. That sounds like a revolution to me!

Also, for obesity, it is known that lactate (and other metabolite) levels predict someones metabolic health and whether they have metabolic syndrome. If we had continuous lactate data or maybe BCAA data (this is probably one I'm not sure they can get easily with current tech) then we could find out when and why metabolic syndrome happens and how best to stop it and reverse it.

I don't just agree with you, I'm taking the first few steps (on the AI side).

I related, scary thing that's lightly regulated is dietary supplements.

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