Medtronic Guardian Sensor 3 vs. Enlite Sensor 2


(MIke) #1

Hello,

I am thinking about getting the Medtronic 670G hybrid closed loop pump, however, my concern is solely about the Guardian Sensor 3 (currently I’m using the Dexcom G4 sensor with my Animas Vibe pump). The readings on the Enlite from what I’ve been told from various people are complete garbage, however, they recently in the last couple months released the Guardian 3. In reading the specs and the FDA report, the MDA percentage is on par with the Dexcom G5, so it should be pretty accurate (around 11%).

Is anyone able to confirm that this is the case? Has anyone had issues with the Guardian 3? Am I making a total mistake by switching over to the 670G?

Thanks for all of your insight!
-Mike


(LoffKat) #2

Hi! Here are the official specs from both Dexcom and Medtronic for their latest and greatest sensors.
MARD - Mean Absolute Relative Deviation (a measurable number qualified by NIH, not speculation or marketing no matter which companies try to downplay this number)
Medtronic 9.64% Source: https://www.medtronicdiabetes.com/products/minimed-670g-insulin-pump-system
Dexcom 9% Source: https://provider.dexcom.com/education-research/evidence/clinical-studies/single-digit-mard-demonstrated-software-used-dexcom-g5

The facts being stated, I was on the Enlite 2 and have been on the Guardian Sensor 3 for almost 5 months now and the Guardian Sensor 3 is VERY accurate. I trust it so much that if it were permitted, I would dose off the SG values :).

That being said, I’m also on the 670G and that has CHANGE MY #%&#@%& life for the best. You can read my full account here:
http://loffkat.blogspot.com/2017/04/the-670g-is-coming-670g-is-coming.html


(LoffKat) #3

I just wrote a whole response and it disappeared :frowning:

I will retype it up later.


(LoffKat) #4

Hi! Let’s get the details straight first. Here are the Mean Absolute Relative Deviation numbers
(a measurable number, not speculation or marketing as some companies try to make you believe.)
Medtronic 9.64% Source: https://www.medtronicdiabetes.com/products/minimed-670g-insulin-pump-system
Dexcom 9% Source: https://provider.dexcom.com/education-research/evidence/clinical-studies/single-digit-mard-demonstrated-software-used-dexcom-g5

So they’re pretty darn close in accuracy.
That being said, I am currently using the 670G with the Guardian Sensor 3 sensors and they are GREAT. If it were permitted, I’d dose off SG values…  The system has lowered my A1c 1.1% in 4 months of using it. I have hope for my diabetes like I never have before.
I used the Enlites in the past and didn’t have as many issues as I’ve heard some people have, but I also took time to troubleshoot if it was not accurate.

I write a blog about the 670G when I first started using it because I thought it was important to document the details. Please take a look at let me know if you have any questions.


(LoffKat) #5

Hi! Let’s get the details straight first. Here are the Mean Absolute Relative Deviation numbers
(a measurable number, not speculation or marketing as some companies try to make you believe.)
Medtronic 9.64% Source: https://www.medtronicdiabetes.com/products/minimed-670g-insulin-pump-system
Dexcom 9% Source: https://provider.dexcom.com/education-research/evidence/clinical-studies/single-digit-mard-demonstrated-software-used-dexcom-g5

So they’re pretty darn close in accuracy.
That being said, I am currently using the 670G with the Guardian Sensor 3 sensors and they are GREAT. If it were permitted, I’d dose off SG values…  The system has lowered my A1c 1.1% in 4 months of using it. I have hope for my diabetes like I never have before.
I used the Enlites in the past and didn’t have as many issues as I’ve heard some people have, but I also took time to troubleshoot if it was not accurate.

I write a blog about the 670G when I first started using it because I thought it was important to document the details. Please take a look at let me know if you have any questions.


(LoffKat) #6

Ok, I think because of the links the forum will not let me post my response. So here it is, kinda cryptic around the urls. Delete the extra spaces.

Hi! Let’s get the details straight first. Here are the Mean Absolute Relative Deviation numbers
(a measurable number, not speculation or marketing as some companies try to make you believe.)
Medtronic 9.64% Source: https :// www.medtronicdiabetes.com/products/minimed-670g-insulin-pump-system
Dexcom 9% Source: https :// provider.dexcom.com/education-research/evidence/clinical-studies/single-digit-mard-demonstrated-software-used-dexcom-g5
So they’re pretty darn close in accuracy.
That being said, I am currently using the 670G with the Guardian Sensor 3 sensors and they are GREAT. If it were permitted, I’d dose off SG values… :slightly_smiling_face: The system has lowered my A1c 1.1% in 4 months of using it. I have hope for my diabetes like I never have before.
I used the Enlites in the past and didn’t have as many issues as I’ve heard some people have, but I also took time to troubleshoot if it was not accurate.

I wrote a blog about the 670G when I first started using it because I thought it was important to document the details. Please take a look at let me know if you have any questions.
loffkat.blogspot.com/2017/04/the-670g-is-coming-670g-is-coming. html


(Wagginpitbull) #7

I switched from Dexcom to the Guardian sensor and I’ve had problems. I think it might be easier to switch from Enlite to Guardian, because then you’re already used to the quirks of Medtronic’s sensors. I submitted a lengthy post about my issues with the Guardian, but it never appeared. I’ll post my issues with the Guardian in a post later today …im runnng late for work right now, so can’t give a thorough explanation at the moment.


(Wagginpitbull) #8

I have been using the 670G since June. Previously I was using the Dexcom sensor and Making the change has been difficult for me. Issues I have with the Medtronic’s sensor are:

  1. The clamshell design - Dexcom attaches flat onto your skin, but Medtronic’s clamshell results in a gap between the sensor and your skin. When I sweat, I get an angry rash under the clamshell.

  2. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.

  3. Calibration problems - Medtronic sensors seem more finicky about when to calibrate. In the past week, it has rejected my calibration at least 3 times (*see note below). I think the rejected calibrations are due to my BG’s being too high at the time of calibration and/or because there’s too big a difference between my # and the sensor’s (in my experience both Medtronic and Dexcom sensors are less accurate with high BGs).

When a calibration is rejected, it tells you to wait 15 minutes and try calibrating again. If it rejects 2 calibrations in a row, it requires you to replace the sensor. Having experienced this a few times, when it rejects my calibration, I decide to wait until my BG is in normal range and is not moving. Typically this is several hours later (usually at the end of work) because I don’t have time to sit around and test & retest until my BGs are golden.
*NOTE: I have ADD & I eat a near-vegan diet. As a result, my BG’s may hit extreme highs and lows more frequently than typical due to forgetting to bolus, forgetting to eat everything I bolused for, and tending to eat more carbs than recommended.

  1. If you are late with a calibration, it bumps you out of auto mode (closed loop)** and eventually it stops recording sensor readings altogether. I’ve had this happen several times while I am asleep. Realistically calibrating before bed shouldn’t be such a big problem, but due to the calibration problem previously mentioned, I may decide to wait to calibrate and then fall asleep without having calibrated.
    **NOTE: Bumping you out of auto-mode might be a requirement for FDA approval. You wouldn’t want insulin decisions based on readings from a sensor that isn’t calibrated. However, I wish it would continue to record sensor readings and alarm if you go low. It does give a calibration alarm every hour, but in the middle of the night, I either sleep through the alarm or ignore it. I tend to respond to hypo alarms even in the middle of the night :wink:

(Wagginpitbull) #9

My post hasn’t shown up, so I’m re-posting, but breaking it into smaller segments…

I have been using the 670G since June. Previously I was using the Dexcom sensor and Making the change has been difficult for me. Issues I have with the Medtronic’s sensor are:

  1. The clamshell design - Dexcom attaches flat onto your skin, but Medtronic’s clamshell results in a gap between the sensor and your skin. When I sweat, I get an angry rash under the clamshell.

  2. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.


(Wagginpitbull) #10

I have been using the 670G since June. Previously I was using the Dexcom sensor and Making the change has been difficult for me. Issues I have with the Medtronic’s sensor are:

  1. The clamshell design - Dexcom attaches flat onto your skin, but Medtronic’s clamshell results in a gap between the sensor and your skin. When I sweat, I get an angry rash under the clamshell.

  2. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms

  3. Calibration problems - Medtronic sensors seem more finicky about when to calibrate. In the past week, it has rejected my calibration at least 3 times (*see note below). I think the rejected calibrations are due to my BG’s being too high at the time of calibration and/or because there’s too big a difference between my # and the sensor’s (in my experience both Medtronic and Dexcom sensors are less accurate with high BGs).

When a calibration is rejected, it tells you to wait 15 minutes and try calibrating again. If it rejects 2 calibrations in a row, it requires you to replace the sensor. Having experienced this a few times, when it rejects my calibration, I decide to wait until my BG is in normal range and is not moving. Typically this is several hours later (usually at the end of work) because I don’t have time to sit around and test & retest until my BGs are golden.
*NOTE: I have ADD & I eat a near-vegan diet. As a result, my BG’s may hit extreme highs and lows more frequently than typical due to forgetting to bolus, forgetting to eat everything I bolused for, and tending to eat more carbs than recommended.

  1. If you are late with a calibration, it bumps you out of auto mode (closed loop)** and eventually it stops recording sensor readings altogether. I’ve had this happen several times while I am asleep. Realistically calibrating before bed shouldn’t be such a big problem, but due to the calibration problem previously mentioned, I may decide to wait to calibrate and then fall asleep without having calibrated.
    **NOTE: Bumping you out of auto-mode might be a requirement for FDA approval. You wouldn’t want insulin decisions based on readings from a sensor that isn’t calibrated. However, I wish it would continue to record sensor readings and alarm if you go low. It does give a calibration alarm every hour, but in the middle of the night, I either sleep through the alarm or ignore it. I tend to respond to hypo alarms even in the middle of the night :wink:

(Wagginpitbull) #11

I’m having trouble getting my post to show up. Here’s my third try…
I have been using the 670G since June. Previously I was using the Dexcom sensor and Making the change has been difficult for me. Issues I have with the Medtronic’s sensor are:

  1. The clamshell design - Dexcom attaches flat onto your skin, but Medtronic’s clamshell results in a gap between the sensor and your skin. When I sweat, I get an angry rash under the clamshell.

(Wagginpitbull) #12
  1. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.

(Wagginpitbull) #13

I’m trying multiple posts that are shorter in length. Here’s part 2 of 4…
2. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.


(Wagginpitbull) #14

I posted a part 2, but it hasn’t appeared yet. Waiting a day to see if it shows up or not


(Wagginpitbull) #15
  1. Calibration problems - Medtronic sensors seem more finicky about when to calibrate. In the past week, it has rejected my calibration at least 3 times (*see note below). I think the rejected calibrations are due to my BG’s being too high at the time of calibration and/or because there’s too big a difference between my # and the sensor’s (in my experience both Medtronic and Dexcom sensors are less accurate with high BGs).

When a calibration is rejected, it tells you to wait 15 minutes and try calibrating again. If it rejects 2 calibrations in a row, it requires you to replace the sensor. Having experienced this a few times, when it rejects my calibration, I decide to wait until my BG is in normal range and is not moving. Typically this is several hours later (usually at the end of work) because I don’t have time to sit around and test & retest until my BGs are golden.
*NOTE: I have ADD & I eat a near-vegan diet. As a result, my BG’s may hit extreme highs and lows more frequently than typical due to forgetting to bolus, forgetting to eat everything I bolused for, and tending to eat more carbs than recommended.


(Wagginpitbull) #16
  1. If you are late with a calibration, it bumps you out of auto mode (closed loop)**. In non-auto mode, it will still suspend on low. However, if you still do not calibrate, eventually it stops recording sensor readings altogether. I’ve had this happen several times while I am asleep. Realistically calibrating before bed shouldn’t be such a big problem, but due to the calibration problem previously mentioned, I may try to wait to calibrate and then fall asleep without having calibrated.
    **NOTE: Bumping you out of auto-mode might be a requirement for FDA approval. You wouldn’t want insulin decisions based on readings from a sensor that isn’t calibrated. However, I wish it would continue to record sensor readings and alarm if you go low (even if it can’t suspend on low). It does give a calibration alarm every hour, but in the middle of the night, I either sleep through the alarm or ignore it BUT I tend to respond to hypo alarms even in the middle of the night :wink:

(Wagginpitbull) #17

Looks like my part 2 post is not gonna post, so I’m resubmitting it…

  1. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.

(Wagginpitbull) #18
  1. The taping procedure - with Dexcom, you use the built-in inserter, remove the backing of the tape, click the transmitter in place & then you’re done. With Medtronic, you put the sensor into the inserter, use the inserter, remove the backing of the tape, attach an additional piece of tape, click the transmitter in place, attach a third piece of tape & then you’re done --I also have to prep the site beforehand with some tacky stuff to help reduce the rash, but if you don’t get the rash, that’s not a required step. Since I live alone, the added taping requirements make placing the sensor on my arm, although maybe once I become more skilled I’ll be able to manage arms.

(Wagginpitbull) #19

Hmmph! I’m not sure what the issue is, but my part 2 message won’t post, so I’m gonna try re-writing it…

Another problem I have with Medtronic’s sensor is the taping procedure. For Dexcom, you simply use their built-in inserter, remove the backing of the tape, click the transmitter in place and you’re good to go.

With Medtronic, you have to load the inserter, use it, and remove the backing of the tape (pretty much like Dexcom). But then you need to affix tape to secure the sensor but make sure you don’t block the spot where the transmitter attaches, then you click the transmitter in place, then you affix another piece of tape to secure the transmitter. If the sensor shifts before it’s properly secured, you may end up with a sensor failure. I have given up on putting the sensor in my arm (my preferred spot with Dexcom) because it’s too difficult for me to manage taping Medtronic’s sensor correctly on my arm. Maybe after a few more months of inserting in my leg I’ll be skilled enough to try an arm insertion, but for now it’s impossible for me to manage it.


(Dan Leslie) #20

My wife just had to replace her 630G under warranty and noe can’t get to pump to calibrate. I had it search and locate the sensor and it warmed up then said calibrate now! but when she checks her BS the pump says “snooze?” yes or no and will not calibrate. The pump receives the BS from her Contour fingerstick and uses it for the bolos wizard but will not calibrate. I guess I’ll spend another 1 1/2 hrs on helpline hold for them to tell me to replace the sensor.