Richard said : I think people are making this topic more confusing than it
needs to be by not being clear.
Yes, sorry for my part in that.
On Mon, Feb 3, 2020 at 12:01 PM Kay Malmquist <kay.malmqu...@gmail.com>
wrote:
> I understand the disposable sensors, but what is the disposable
> transmitter for?
>
Conceptually, there's two major elements to any continuous glucose metering
solution (CGM):
1. Sensor (all of the current systems use a small wire that is embedded
into your skin, reading the interstitial fluid).
1. These are disposable.
2. These have some local memory.
3. These have some sort of power source (but since disposable, not
user interesting)
4. These cannot be reinserted
2. Reader : get information from the sensor
1. For FDA certification purposes, these were developed first; may be
"mandatory" to write an RX for
2. These may communicate directly with the sensor, or via an
intermediary.
1. Dexcom chose to make the communication to the sensor via
Bluetooth. This is well integrated with the sensor, so it's
not so obvious
that you've got some other channel to the sensor. By using bluetooth,
phones and other medical devices can communicate directly and
across a fair
distance. It also provides for true continuous monitoring
(although what's
implemented is discrete ... 1 measurement every few minutes
... which is
more than adequate for treatment purposes, even automated insulin
delivery systems)
2. Freestyle uses NFC, which means data is only transferred in
batches, at user initiated intervals
1. The "pro" version only stores 1 reading for every 15m or so;
but stores a full 2 weeks of data. These aren't supposed
to be sold to
individuals, but to clinics and require a special reader
(the iphone app
refuses to talk to the pro version of the sensors)
Where it gets a bit messy is in the 2.1 vs 2.2 area. There are a couple of
vendors of "dongles" which speak NFC on one side (to the sensor) and
bluetooth to your phone (or whatever). The dexcom system *includes such a
device* but it's not so obvious that's what is does (and it may not use
NFC, whatever the communication between sensor and transmitter is
proprietary to dexcom). As to why they made it disposable ... other than
profit, I have no doubt it made the FDA certification easier. Nothing
exposed, nothing the user can screw up. Nothing that degrades over the
expected lifetime of the device. On the plus side, it makes the dexcom
easier to interface with and use (since it's well integrated it
mechanically stays in place well, etc.).
The Libre, lacking that extra bit ... is less expensive to operate, but
it's not suitable for folks who need:
1. real time alarms
2. integration with insulin pumps or other delivery systems
However, third parties stepped up, reverse engineered the NFC interface and
provide a *reusable* transmitter that closes the gap between the dexcom and
Libre systems. However, since it's not provided by Abbot, the quality of
the integration is mixed (better if you want to hack on the code and
customize, less good if you want an out of the box solution).
I'm surprised that Abbot didn't step up and provide a certified factory
solution (but the FDA approval process is slow, painful and expensive. So
perhaps they are still in process; perhaps it's a next generation thing. I
have no inside information).
Since the dexcom solution is all provided by the factory (and they do
quality work) I believe it is both more accessible, and easier to use.
Since the Libre+third party solution has at least one extra party, there's
both ease of use and accessibility challenges. The cost savings may make it
worthwhile. Or, if you really only need the in-depth, detailed
*retrospective* statistics, the Libre solution (minus the extra
transmitter) may suit your needs well (e.g. a non-insulin dependent
individual who "just" needs to continue tweaking their diet ... or
medication regimen and not make minute by minute treatment adjustments).
Indeed, the "pro" version which your clinic reads the results after 2 weeks
may be ideal (I used it for my diabetic cat for a few weeks).
Personally, I fall in the middle. I don't need alerts; but I do need enough
feedback to make optimal food choices. The bluetooth transmitter isn't
vital, but it does provide better data resolution ... but it is a bit of a
PITA (perhaps after a few months I'll have worked out the kinks for my
personal use cases). I'd have rather stayed with Dexcom, but the cost
savings was substantial ... because my insurance won't cover a CGM (I'm not
sick enough) ... which is kinda backwards, in that it will help delay
getting that sick. Oh well, re-engineering our healthcare system is
something we've outsourced to lawyer/politicians.
--
The following information is important for all members of the V iPhone list.
If you have any questions or concerns about the running of this list, or if you
feel that a member's post is inappropriate, please contact the owners or
moderators directly rather than posting on the list itself.
Your V iPhone list moderator is Mark Taylor. Mark can be reached at:
mk...@ucla.edu. Your list owner is Cara Quinn - you can reach Cara at
caraqu...@caraquinn.com
The archives for this list can be searched at:
http://www.mail-archive.com/viphone@googlegroups.com/
---
You received this message because you are subscribed to the Google Groups
"VIPhone" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to viphone+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/viphone/CAHSokPy_B_2O-v9RS8WFbpG9pT34XCn1sDZoJ%2BqNcuuZCu1LYw%40mail.gmail.com.
