Closed loop system

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Tom1982

Tom1982

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I’m a pump engineer (not insulin pumps unfortunately). To me a closed loop system is a pump that reacts automatically to a signal from a sensor.
Is this effectively what a closed loop system is for insulin pumps too?
Currently trying to suss out what our best option is for our 4 year old daughter.
 
There's some information here on the Diabetes UK pages about it (they don't recommend DIY systems), with links to 4 commercial pumps at the bottom of the page.
But all this is well outside my knowledge, as I'm T2 on pills. Hopefully the more knowledgable forum members know!
 
A closed loop system is where the pump will decrease or increase the amount of insulin depending on what the sensor tells it. The two closed loop systems I know of are the Tandem Tslim pump linked with a Dexcom and a Medtronic pump linked with a Guardian sensor
 
The Dana RS can be looped too, either with its official loop that uses Dexcom, or with Open APS. Yes @Tom1982 a closed loop is as you described. You can also have an open loop, or switch the closed loop off at certain points eg at night.
 
Lily123 said:
A closed loop system is where the pump will decrease or increase the amount of insulin depending on what the sensor tells it. The two closed loop systems I know of are the Tandem Tslim pump linked with a Dexcom and a Medtronic pump linked with a Guardian sensor
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So out of curiosity, why doesn’t everyone want a closed loop system???
 
Tom1982 said:
So out of curiosity, why doesn’t everyone want a closed loop system???
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Like @Inka said. And the fact that most aren’t even offered a pump because the guidelines don’t address many issues of MDI
 
Tom1982 said:
Ahhh right. Is the Dexcom a monthly pay out?
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Often, yes. And most of us aren't offered a pump. (Things are a bit different on both things if you're 4 or (more generally) under 12.)

There are proposed updates to the NICE guidelines which should open up CGMs (like Dexcom) much more broadly to people of all ages with Type 1, and there are trials on closed loop systems which everyone expects to be very positive, and with any luck NICE will give recommendations for them. I'm still not holding my breath, but I hope closed loops will be fairly common within ~5 years. It certainly feels like that's possible, and maybe then I'll be able to get one.
 
Bruce Stephens said:
Often, yes. And most of us aren't offered a pump. (Things are a bit different on both things if you're 4 or (more generally) under 12.)

There are proposed updates to the NICE guidelines which should open up CGMs (like Dexcom) much more broadly to people of all ages with Type 1, and there are trials on closed loop systems which everyone expects to be very positive, and with any luck NICE will give recommendations for them. I'm still not holding my breath, but I hope closed loops will be fairly common within ~5 years. It certainly feels like that's possible, and maybe then I'll be able to get one.
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I’ve never really understood the under 12 bit and if your older but still not an adult you are counted as an adult in the guidelines it’s incredibly annoying
 
The other thing with the closed loop is that the pump not only needs to react to the information from the sensor, it also needs to take account of the delay in action time of the insulin you are using, as well as any active insulin you already have on board. The pumps do this using an algorithm, whether they are in manual or in closed loop.

I have now used the closed loop for nearly a year, and would not want to go back. However 8 do have to fund the sensors. I am using a Medtronic 780 pump with their own sensors.
 
Tom1982 said:
Ahhh right. Is the Dexcom a monthly pay out?
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They have various deals but it’s very roughly £160-180 per month if I remember correctly. No way could I afford that.

Bear in mind also that only a small percentage of people with Type 1 have a pump.
 
Lily123 said:
I’ve never really understood the under 12 bit and if your older but still not an adult you are counted as an adult in the guidelines it’s incredibly annoying
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I guess they want to draw a line somewhere, and while it's inevitably a bit arbitrary 12 feels to me like a plausible age to do it at.

My hope is that with falling costs in sensors and increased appreciation for the value of them and of pumps, maybe gradually there'll be less interest in limiting access to pumps and things for people over 12.
 
Inka said:
They have various deals but it’s very roughly £160-180 per month if I remember correctly. No way could I afford that.

Bear in mind also that only a small percentage of people with Type 1 have a pump.
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So in our case they are talking about various pumps that are available. If it wasn’t a closed loop type could we potentially make up the difference or are we completely on our own unless we go with what’s offered? I was trying to ask that today but they kept going on about reliability and so on.
 
Tom1982 said:
So in our case they are talking about various pumps that are available. If it wasn’t a closed loop type could we potentially make up the difference or are we completely on our own unless we go with what’s offered? I was trying to ask that today but they kept going on about reliability and so on.
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Yes, you could make your own loop if you had an appropriate pump. The people I know who loop have bought the extras themselves but got their pump on the NHS.

I don’t think I’d loop with a young child though personally.
 
Bruce Stephens said:
I guess they want to draw a line somewhere, and while it's inevitably a bit arbitrary 12 feels to me like a plausible age to do it at.

My hope is that with falling costs in sensors and increased appreciation for the value of them and of pumps, maybe gradually there'll be less interest in limiting access to pumps and things for people over 12.
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Hopefully pumps will become available to more people in the coming years
 
Tom1982 said:
So out of curiosity, why doesn’t everyone want a closed loop system???
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Personally I do not think the sensors are accurate enough and as I am sensitive to insulin I suspect I could be in big trouble using it.
 
Inka said:
Yes, you could make your own loop if you had an appropriate pump. The people I know who loop have bought the extras themselves but got their pump on the NHS.

I don’t think I’d loop with a young child though personally.
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Very interesting. Cheers for your input. I just assumed this was the way to go, never considered the merits of doing it another way. Just shows how little we know at the moment!
 
Tom1982 said:
Very interesting. Cheers for your input. I just assumed this was the way to go, never considered the merits of doing it another way. Just shows how little we know at the moment!
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There’s no easy answer to Type 1 sadly. Yes, some things will make life easier, but it’s all a balance of what suits the individual, what they’re prepared to tolerate, how much mentally they want to invest.

What helps most is free - experience. Read lots, be patient and cautious always, and you’ll gradually get experience that is absolutely invaluable.
 
Tom1982 said:
So in our case they are talking about various pumps that are available. If it wasn’t a closed loop type could we potentially make up the difference or are we completely on our own unless we go with what’s offered? I was trying to ask that today but they kept going on about reliability and so on.
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Not all pumps can be looped and your choice of pump will be limited to what your area offer, so a looped system may not be possible.
You need a lot of support with pumps particularly initially and nursing staff are only trained on the ones available in their area, so short of moving to a different area when looped pumps are available, even if you have to self fund the sensors, might be necessary if you have your heart set on a looped system. As I understand it though, it is not a hands off system. You still need to carb count and bolus for food.
 
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