# Medtrum CGM trial



## helli (Mar 15, 2022)

I managed to blag a trial of the Medtrum CGM and have just activated it. 
Apart from being easy to set up , I don't have much to report yet but looking forward to seeing how accurate it is for me and, if not too far out, testing the automatic low suspend. 
My plan is to enable that in a couple of days. 

I will report my findings over the next few days as there does not seem to be many reviews out there (apart from one very damning one from about 5 years ago).


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## rebrascora (Mar 15, 2022)

Exciting stuff! Look forward to reading your updates. Good luck with it!


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## helli (Mar 17, 2022)

Two days into my trial and things are looking good. 
For peace of mind, I am happy that I am able to calibrate the sensor but it has been more accurate than the Libre I had on my other arm.

The Medtrum CGM is similar to the Dexcom in that it has two separate parts - the transmitter which lasts one year and is charged between sensors which last 10 to 14 days. 
The combined size is similar to the Libre and, like the Libre, only approved to be worn on the arm. 

Compared to the Dexcom and Libre, the applicator is small but, disappointingly single use. 

Viewing my current readings and setting the lows and high are all done via the same phone app as my pump (via Bluetooth) which is really handy. However, I am missing the xDrip widget on the lock screen - I have to unlock my phone and open the app to see my current level. Much less effort than pricking a finger but not as good as I am used to.

Today, I turned on the Low Suspend - when the CGM detects my levels are 0.8mmol/l above my low range, it will automatically suspend the pump. It does this in direct communication with my pump so does not need my phone nearby. This culd be handy if I was somewhere that I could not take my phone such as the climbing wall. 

I'll be back with my Low Suspend experience. To be honest, this is what I am most interested in.


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## everydayupsanddowns (Mar 18, 2022)

Sounds great @helli 

Glad it is working well for you - I would find it a massive step backwards not to have some sort of glucose suspend now.

Hopefully Medtrum will develop a lockscreen widget (Dexcom has one for ios) 

Keep us posted with how the experience goes for you. Is that 0.8mmol/L configurable?


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## nonethewiser (Mar 18, 2022)

helli said:


> Two days into my trial and things are looking good.
> For peace of mind, I am happy that I am able to calibrate the sensor but it has been more accurate than the Libre I had on my other arm.
> 
> The Medtrum CGM is similar to the Dexcom in that it has two separate parts - the transmitter which lasts one year and is charged between sensors which last 10 to 14 days.
> ...



All sounds good helli, despite suspending insulin theres still chance of bg dropping isn't there with previous basal on board, do you know if it would communicate with smartwatch or similar for likes of climbing.


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## helli (Mar 22, 2022)

Apologies for the break. Unfortunately I experienced a sensor failure so had to start again. 

I am now back CGMing with auto Low Suspend and Predictive Low Suspend and liking what I am seeing. 

To answer a few questions from above:

@everydayupsanddowns the 0.8 is not configurable but the low range is. When I enabled Low Suspend, I decreased my lower target from 4.5 to 4.0 so the auto-suspend occurs at 4.8. This is better than some auto-suspends which I believe (although my information maybe out of date) are fixed at 6.7 which would be waaaaaay too high for me.

@nonethewiser there is no official coms with a smart watch for climbing and the like. I see xDrip has an option for the older Medtrum A6 CGM. I do not know if they have plans (or a large enough audience) to upgrade this to the Nano CGM. 
However, as the auto-suspend bypasses the phone, I could be confident the suspend would happen if necessary. Unfortunately, climbing tends to send my levels high rather than low ... but that's what my basal climbing profile is for. 

Back to my experiences so far - it is currently more accurate (for me - we are all different) which was a pre-requisite for trialling the auto-suspend. 

There are two options
- Low Suspend 
- Predictive Low Suspend

The Low suspend is the simple suspension when m levels reach a particular level (0.8mmol/l above low range target). It lasts at least 30 minutes but if levels are still low, it continues for up to 2 hours. I can override the suspension at any point. 
I get an alarm on the phone app to tell me the suspension has started. If I ignore it for 10 minutes, my pump starts beeping at me which is a great reminder, especially if my phone gets disconnected or separated. 

The Predictive Low Suspend is when the pump will suspend basal when the levels are predicted to reach a low level in a given period. This takes into consideration the trend line and the current value. The pump will not suspend if I am more than 3.9mmol/l from the low range target and is predicted to fall within 0.8 mmol/l of that level in the configurated time(I can set this between 5 minutes and 40 minutes). 


These suspensions have been working well for me. I usually manually suspend when I get alerts so it is good to be able to back off. This has been great at night and I have had a better night's sleep since using it. 


So far, my feelings are mixed - when the CGM works, I really like it but I am disappointed that the first one failed. 

I will report back with a summary when my sensor expires.


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## everydayupsanddowns (Mar 22, 2022)

helli said:


> are fixed at 6.7 which would be waaaaaay too high for me.



I can only think that is more the ‘target BG’ of a hybrid closed loop?

Medtronic’s predictive glucose suspend and Tandem’s Basal IQ both allow low limits to be user defined within ranges of 3.5-5.5 or similar, and then use an algorithm to determine how far in advance of that low limit to shut off basal.

With the hybrid closed loops that are adding insulin as well as suspending basal the commercial algorithms tend to have a fairly conservative target point to aim to return you to, and that’s where I’ve heard people mentioning frustrations with fixed values in the mid 6’s.

Interestingly my Dexcom 90 day average with the help of Control IQ does tell me that my average is indeed 6.7mmol/L with 92% between 4-10. Though there have been times where the average has been more like 5.9-6.0. And my low limit for suspends is set well below that midpoint target.


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## helli (Mar 29, 2022)

As I enter the last couple of days of life for my Medtrum CGM (my Libre is applied and bedding in), I thought I would write up my final pros and cons

*Pros*

Easy to apply
Small applicator (less plastic than LIbre and Dexcom)
Small - similar size to a Libre 1 and 2 when applied
Easy to start - no need for NFC scanning
Single app for pump and CGM - able to see highs and lows with insulin dose on a single graph without double entry
Accurate for me - as with Libre, I check twice a day (morning and night) and if high or low
Official app allows calibration - this helps wit the acuracy and peace of mind. With Libre I have to use 3rd party app
Low Glucose Suspend and Predicted Low Glucose Suspend - these features are the game changer for me. I have slept much better over the last 2 weeks when I don't have to wake to check I am hypo or worry about an alert waking my partner

*Cons*

50% failure rate - I don't know whether I was unlucky with the first one and if I had 20 sensors, that would be my only failure or whether it would be 10 failures
No lock/home screen widget - with xDrip, I love being able to glance at my phone to check my levels without the need to unlock it and open the app
scruffy tape - in addition to the sticky backing, Medtrum also provide an "over- tape" which goes around the sensor to hold it in place. This is very much like a special-sized tegaderm which, over time has started to peel off and look scruffy. This is not a problem in a week when snow is forecast but not ideal in the summer with short sleeves.
Predictive Low Glucose Suspend over eager when I have just eaten - if my levels are on the lower side (but not hypo) when I bolus, Fiasp can act pretty fast and my levels may drop a little before the carbs are absorbed. This feature notices and decides that I am about to hypo (I am not because I am eating) so suspends the basal for 30 minutes. As a result I go high because I don't have enough insulin for the carbs. I suspect this is something I will learn to handle - maybe bolus later or temporarily turn off the feature
Not available on prescription - I ill have to self fund the CGM at least for now. I have requested the price and will make a decision based on that.


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## Bruce Stephens (Mar 29, 2022)

helli said:


> I have requested the price and will make a decision based on that.


Judging by 



__ https://twitter.com/i/web/status/1276133816361418754 it may well be £35 a sensor. Though that was a couple of years ago (and may even be a different product), so it's as well to get the official current price.

Seems a bit daft they don't just give the price on the website. If they're offering it for sale (as they are) just give us the damn price.


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## helli (Mar 29, 2022)

Bruce Stephens said:


> Judging by
> 
> 
> 
> ...


That’s a different sensor but I agree it is annoying that I have to ask for the price.


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## Lucyr (Mar 29, 2022)

Bruce Stephens said:


> Judging by
> 
> 
> 
> ...


Libre are just under £50 a sensor if self funding, so I’d guess at that


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## helli (Mar 29, 2022)

Lucyr said:


> Libre are just under £50 a sensor if self funding, so I’d guess at that


It is not relevant as this is a different old Medtrum sensor.
I would rather wait for Medtrum to answer my question than guess based on an old model.


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## helli (Mar 31, 2022)

So, the cost for Medtrum CGM is …


Drum Roll please ….​

£35 for each sensor guaranteed to last 10 days but should last 14 days

plus £200 for a transmitter which is guaranteed to last 1 year

You can buy starter packs which basically halves the price:
- 1 transmitter plus 4 sensors are £170

This is a little more confusing than the Libre pricing but works out pretty close - about £39 for 14 days of sensor (assuming it lasts full term) and transmitter.


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## Bruce Stephens (Mar 31, 2022)

Meanwhile Dexcom's G6 subscription offer is "Make monthly payments of just £159" if you sign up for a year.


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