MM Sensor timers, when to restart and recharge Rating Options

[Linda B]

To all MM CGMS Users:

Here are some basic facts about using the sensors. I have posted this in the past, but as many of you are new to the CGMS system, you probably didn't see the previous posts.

The software in the MM CGMS system is programmed to end the sensor after 72 hours of use. Most of you know that at this time (after the first 3 days) you simply do a 'start-new sensor' , it asks for a Meter BG, and you are good for another 3 days. I'm not sure if you realize that you do not have to wait until the sensor end. Since starting a new sensor requires a Meter BG, it is important to time this when it would be 'safe' to do a calibration. Ideally this is when your BG has been stable for the past 15 minutes.

There is another timer in the software. This is a 7 day transmitter timer. After the transmitter has been in use for 7 days, it will stop working and will give you a 'weak signal' alarm. The only way to fix this is to recharge the transmitter. It is the placement on the charger that resets the timer. I am not sure if the timer starts counting down when the transmitter is removed from the charger or when it is connected to the sensor, because I only remove my transmitter from the charger just before connecting it to the sensor.
Support has told me to wait 1 full minute whenever you disconnect the transmitter from the charger or a sensor before connecting it to another device.

When the software goes through a start:new sensor cycle, it does different things during those first 2 hours than it does normally. It will not work as effectively for the first 24 hours. For that reason, I recommend charging the transmitter on the 6th day instead of waiting for the weak sensor. There is no point in going through two start cycles just one day apart.

Whenever you do a start new sensor, there is a 6 hour timer between the start and the first calibration. You DO NOT have to wait for the Meter BG. You can calibrate whenever it is a good time. An example of when this is important is if the 6 hour Meter BG Now will happen when you are sleeping. Just do the calibration before you go to bed.

I often do the 2nd calibration as soon as the first one 'takes'. When I see a SG number on my screen after a start, I just go back in and do another calibration (if I'm sure my BG hasn't changed).

It is best to calibrate when you know your BG is stable. There is no need to wait for a Meter BG at any time during the life of the sensor.

I hope this has helped some of you 'newbies' to be able to get longer use out of your sensors. I know a lot of people are able to get 2 weeks out of a sensor.

For some reason my interstitial fluid 'dries up' around the 6th day so I just change my sensors every 6 days.

Linda B.

[Beowulf]

Excellent post Linda! Thank you! Even for some of us that are used to the system its good to see some reminders for us all. Thanks!!

Justin

[Joanie]

Fantastic post! Thank you SO much for this information!

[tedm]

Two quick comments. I am not absolutely sure of these but I am pretty sure:
(1) The 7-day timer starts when you connect the sensor, not when the transmitter comes off the charger.
(2) To reset the 7-day timer, you only have to disconnect the transmitter (for long enough, 1 minute to be safe). You do not need to change it. Having said that, you might as well charge it when you have it disconnected.

I'm pretty sure that the transmitter is powered up only when connected to something (and for a few seconds after disconnecting). To save battery power, nothing runs while it is disconnected.

Otherwise, a very nice and concise guide.

[gigem99]

Two quick comments. I am not absolutely sure of these but I am pretty sure:
(1) The 7-day timer starts when you connect the sensor, not when the transmitter comes off the charger.
(2) To reset the 7-day timer, you only have to disconnect the transmitter (for long enough, 1 minute to be safe). You do not need to change it. Having said that, you might as well charge it when you have it disconnected.

I did an experiment this morning. I left my transmitter attached to the sensor for the entire 7 days, and got the "weak signal" alarm at exactly 168 hours after connecting the transmitter. So, Ted's comment (1) is absolutely correct. Actually, it is from the time you see the little green light blink the 6 times (or however many times it blinks).

Secondly, I disconnected for 5 minutes and re-connected. The little green lite never flashed like it usually does after just a minute or two. After 15 minutes, I got the "lost sensor" alarm. At that point, I disconnected and re-charged. I am left with the conclusion that the 7-day timer is re-set when the transmitter is connected to the transmitter charger. Just reconnecting it to the sensor will not re-set it.

However, the timer re-starts when the transmitter is connected to the sensor.

I hope I am not confusing matters. Linda's post is excellent.

Tom

[JohnG]

I did an experiment this morning. I left my transmitter attached to the sensor for the entire 7 days, and got the "weak signal" alarm at exactly 168 hours after connecting the transmitter.
Tom

Tom
You are correct and the manual is wrong, it says you can use the MiniLink for 14 days of continuous glucose monitoring immediately following a full charge (Page 11)

JohnG

[tedm]

Secondly, I disconnected for 5 minutes and re-connected. The little green lite never flashed like it usually does after just a minute or two. After 15 minutes, I got the "lost sensor" alarm. At that point, I disconnected and re-charged. I am left with the conclusion that the 7-day timer is re-set when the transmitter is connected to the transmitter charger. Just reconnecting it to the sensor will not re-set it.

However, the timer re-starts when the transmitter is connected to the sensor.

I am surprised but obviously wrong on my second point.

I apologize for the error and hope it didn't cause anyone a problem.

[Gregg C.]

To all MM CGMS Users:

Here are some basic facts about using the sensors. I have posted this in the past, but as many of you are new to the CGMS system, you probably didn't see the previous posts.

The software in the MM CGMS system is programmed to end the sensor after 72 hours of use. Most of you know that at this time (after the first 3 days) you simply do a 'start-new sensor' , it asks for a Meter BG, and you are good for another 3 days. I'm not sure if you realize that you do not have to wait until the sensor end. Since starting a new sensor requires a Meter BG, it is important to time this when it would be 'safe' to do a calibration. Ideally this is when your BG has been stable for the past 15 minutes.

There is another timer in the software. This is a 7 day transmitter timer. After the transmitter has been in use for 7 days, it will stop working and will give you a 'weak signal' alarm. The only way to fix this is to recharge the transmitter. It is the placement on the charger that resets the timer. I am not sure if the timer starts counting down when the transmitter is removed from the charger or when it is connected to the sensor, because I only remove my transmitter from the charger just before connecting it to the sensor.
Support has told me to wait 1 full minute whenever you disconnect the transmitter from the charger or a sensor before connecting it to another device.

When the software goes through a start:new sensor cycle, it does different things during those first 2 hours than it does normally. It will not work as effectively for the first 24 hours. For that reason, I recommend charging the transmitter on the 6th day instead of waiting for the weak sensor. There is no point in going through two start cycles just one day apart.

Whenever you do a start new sensor, there is a 6 hour timer between the start and the first calibration. You DO NOT have to wait for the Meter BG. You can calibrate whenever it is a good time. An example of when this is important is if the 6 hour Meter BG Now will happen when you are sleeping. Just do the calibration before you go to bed.

I often do the 2nd calibration as soon as the first one 'takes'. When I see a SG number on my screen after a start, I just go back in and do another calibration (if I'm sure my BG hasn't changed).

It is best to calibrate when you know your BG is stable. There is no need to wait for a Meter BG at any time during the life of the sensor.

I hope this has helped some of you 'newbies' to be able to get longer use out of your sensors. I know a lot of people are able to get 2 weeks out of a sensor.

For some reason my interstitial fluid 'dries up' around the 6th day so I just change my sensors every 6 days.

Linda B.

Great post Linda. One other comment I would like to add: When you do the "Start New Sensor" command after 72 hours, immediately after that, click on "Find Lost Sensor", this way you will not have to do a BG in two hours, just at six hours. Hope that is not confusing.
-Gregg

[Liz]

Great post Linda. One other comment I would like to add: When you do the "Start New Sensor" command after 72 hours, immediately after that, click on "Find Lost Sensor", this way you will not have to do a BG in two hours, just at six hours. Hope that is not confusing.
-Gregg

I'm confused! After 72 hours, I get the Sensor End message. I just go into the sensor menu and choose Start New Sensor. Within minutes, I'm asked for a meter BG. You never have to wait two hours unless you have removed the transmitter. I do not remove it after the first 72 hours, I just tell the pump I'm starting a new sensor and it's good to go for another 3 days. After that first meter BG you will have to do another within 6 hours, just as if you did actually insert a brand new sensor.

[JohnG]

I'm confused! After 72 hours, I get the Sensor End message. I just go into the sensor menu and choose Start New Sensor. Within minutes, I'm asked for a meter BG. You never have to wait two hours unless you have removed the transmitter. I do not remove it after the first 72 hours, I just tell the pump I'm starting a new sensor and it's good to go for another 3 days. After that first meter BG you will have to do another within 6 hours, just as if you did actually insert a brand new sensor.

Liz
I think he is talking about after the 168 hr time limit when you are forced to do a recharge to reset the timer on the transmitter.
(But could be wrong I have not tryed this)

I have never used the find lost sensor feater my trainer said to just use the start new sensor feater (And the find lost sensor feater was useless).

If this works I would think you could do a recharge anytime it was convenient and not have to deal with the 2 hr wait time except for
when inserting a new sensor.

I try to never go past the 168 hour (7 day limit) I'm trying to do the least amount of tissue damage possible. I'm already having problems
going 72 hours before having to change a infusion sight.

JohnG

This post has been edited by JohnG: May 31 2009, 01:05 PM

[Linda B]

When you do the "Start New Sensor" command after 72 hours, immediately after that, click on "Find Lost Sensor", this way you will not have to do a BG in two hours, just at six hours. Hope that is not confusing.
-Gregg

After the first 72 hours, you only have to do a 'start new sensor' it will not go through a 2 hour start up. There is no need to do a find lost sensor.
Linda B.