Search
Search titles only
By:
Search titles only
By:
Home
Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
Members
Current visitors
New profile posts
Search profile posts
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to Thread
Guest, we'd love to know what you think about the forum! Take the
Diabetes Forum Survey 2024 »
Home
Forums
Diabetes Discussion
Ask A Question
Libre sensor activation time
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Scott-C" data-source="post: 1416146" data-attributes="member: 374531"><p>I decided to try it after reading this article which explains a lot, even though most of it is way above my O grade and Higher chemistry!</p><p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/</a></p><p></p><p>Here's why it's a good idea to wait for a while before activating:</p><p></p><p style="margin-left: 20px">"Despite the advances in the making of sensors with new and improved designs and materials, sensor insertion causes trauma to the insertion site. It can disrupt the tissue structure, provoking an inflammatory reaction that can consume glucose followed by a repair process. The interaction of the sensor with the traumatized microenvironment warrants the need for a waiting period for the sensor signal to stabilize, and that period varies depending on the sensor type."</p> <p style="margin-left: 20px"></p><p>That explains why people complain of low readings in the first dayif they activate just after insertion: the wounded cells, repair cells and defence mechanisms which come along to attack the sensor as a foreign body eat up glucose around the sensor so the sensor is accurately reporting low glucose in that area even though glucose elsewhere is fine.</p><p></p><p>And here is why starting it while stable matters:</p><p></p><p style="margin-left: 20px">"Such calibrations transforms the sensor signal into a glucose value and assumes that the plasma-to-IF glucose gradient remains relatively constant. This assumption will not be valid if sensors are calibrated during rapid changes in plasma glucose, which is a major source of sensor error."</p> <p style="margin-left: 20px"></p><p>It just seemed to me to make sense that the "plasma-to-IF glucose gradient" was likely to be closest when I'd been sleeping all night with no food/bolus, stress, steady heart rate. The gradual seepage of glucose from blood to IF would be most likely to have balanced out, so if we're asking the sensor to make guess about what BG is, why not start when the two are most closely aligned.</p><p></p><p></p><p></p><p>Next time you take a sensor out, have a close look at the filament. There's some black stuff on it and some metal. The black stuff is an enzyme, glucose oxidase,which breaks passing glucose down into other chemicals. When the glucose breaks down, it gives off electrons. That's basically the same as an electric current, which the metal bit picks up.The more glucose there is to break down, the more current there is, so the computing bit does some sums and says with this much current, my guess is that there's this much glucose. It's not measuring the glucose as such: it's measuring the current, and inferring what the glucose is. When I first read about this, my first thought was that it's extraordinary that we get any useful reading at all, so I've not got a lot of patience for people who say, ooh,it's not the same as my meter!</p><p></p><p>When I was a kid, I wanted to be an "inventor" (look, dad, I've built a robot!), didn't work out that way, but I've always been curious about things (especially when I'm forking out a hundred quid a month for them!), so I picked up a cheap copy of this book off Amazon: <a href="https://www.amazon.co.uk/Vivo-Glucose-Sensing-Chemical-Analysis/dp/0470112964" target="_blank">https://www.amazon.co.uk/Vivo-Glucose-Sensing-Chemical-Analysis/dp/0470112964</a></p><p></p><p>It gives a full history of glucose sensing with a focus on cgm for the people who develop them. Highly technical and way beyond me, but it's deeply impressed me with the way developers are dealing with some incredibly complex problems. It starts off by mentioning the Ebers papyrus from, get this, <em>1550 BC</em>, which is (disputed) as being the first analysis of diabetes. So, it can't all be blamed onn the eatwell plate! Brief reference to "water tasters" - a guy must have had some bad karma in his life to get that job!</p><p></p><p></p><p style="margin-left: 20px"></p></blockquote><p></p>
[QUOTE="Scott-C, post: 1416146, member: 374531"] I decided to try it after reading this article which explains a lot, even though most of it is way above my O grade and Higher chemistry! [URL]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/[/URL] Here's why it's a good idea to wait for a while before activating: [INDENT]"Despite the advances in the making of sensors with new and improved designs and materials, sensor insertion causes trauma to the insertion site. It can disrupt the tissue structure, provoking an inflammatory reaction that can consume glucose followed by a repair process. The interaction of the sensor with the traumatized microenvironment warrants the need for a waiting period for the sensor signal to stabilize, and that period varies depending on the sensor type." [/INDENT] That explains why people complain of low readings in the first dayif they activate just after insertion: the wounded cells, repair cells and defence mechanisms which come along to attack the sensor as a foreign body eat up glucose around the sensor so the sensor is accurately reporting low glucose in that area even though glucose elsewhere is fine. And here is why starting it while stable matters: [INDENT]"Such calibrations transforms the sensor signal into a glucose value and assumes that the plasma-to-IF glucose gradient remains relatively constant. This assumption will not be valid if sensors are calibrated during rapid changes in plasma glucose, which is a major source of sensor error." [/INDENT] It just seemed to me to make sense that the "plasma-to-IF glucose gradient" was likely to be closest when I'd been sleeping all night with no food/bolus, stress, steady heart rate. The gradual seepage of glucose from blood to IF would be most likely to have balanced out, so if we're asking the sensor to make guess about what BG is, why not start when the two are most closely aligned. Next time you take a sensor out, have a close look at the filament. There's some black stuff on it and some metal. The black stuff is an enzyme, glucose oxidase,which breaks passing glucose down into other chemicals. When the glucose breaks down, it gives off electrons. That's basically the same as an electric current, which the metal bit picks up.The more glucose there is to break down, the more current there is, so the computing bit does some sums and says with this much current, my guess is that there's this much glucose. It's not measuring the glucose as such: it's measuring the current, and inferring what the glucose is. When I first read about this, my first thought was that it's extraordinary that we get any useful reading at all, so I've not got a lot of patience for people who say, ooh,it's not the same as my meter! When I was a kid, I wanted to be an "inventor" (look, dad, I've built a robot!), didn't work out that way, but I've always been curious about things (especially when I'm forking out a hundred quid a month for them!), so I picked up a cheap copy of this book off Amazon: [URL]https://www.amazon.co.uk/Vivo-Glucose-Sensing-Chemical-Analysis/dp/0470112964[/URL] It gives a full history of glucose sensing with a focus on cgm for the people who develop them. Highly technical and way beyond me, but it's deeply impressed me with the way developers are dealing with some incredibly complex problems. It starts off by mentioning the Ebers papyrus from, get this, [I]1550 BC[/I], which is (disputed) as being the first analysis of diabetes. So, it can't all be blamed onn the eatwell plate! Brief reference to "water tasters" - a guy must have had some bad karma in his life to get that job! [INDENT][/INDENT] [/QUOTE]
Verification
Post Reply
Home
Forums
Diabetes Discussion
Ask A Question
Libre sensor activation time
Top
Bottom
Find support, ask questions and share your experiences. Ad free.
Join the community »
This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies.
Accept
Learn More.…