Professor Nick Oliver Imperial College London, BiAP, bio-inspired artificial pancreas, ABC4D, Chris

KITLIVING

system, something we ended up calling

the silicon beta-cell. Once we'd gone

beyond the difference in interpretation

we were able to make something that

was testable, and which worked. Having

begun in 2006, it took five years to get the

silicone beta cell from lab to clinic, with the

first human study taking place in 2011."

At that time, the study used the

Medtronic Enlite CGM. Oliver explains,

"As all CGM use interstitial body fluid,

there's always a slight lag in terms of

getting an accurate reading, but the

speed and accuracy should be sufficient

for an artificial pancreas. However one

person's diabetes is individual -- their

hormones, their daily activity -- are

distinct to themselves. Algorithms can

only respond to a glucose reading,

therefore they are always reactive, and

as a result it can be challenging to hit

the target glucose and stay there. There

are slow but sure improvements going

on with all the factors comprising an

artificial pancreas. Faster insulins are now

on the horizon, which are likely to be an

improvement. The newest Medtronic

pump, the 670g, can be programmed for

much greater automation, but still relies

on manual bolusing based on glucose

and carbohydrate information alone."

Which leads on to another question,

should a blood glucose reading and a

carb count be the only factors upon which

to base a bolus? Says Oliver, "What about

hormones, exercise? And, we know we

can make mistakes estimating carbs. Can

an artificial pancreas be more adaptive? I

think that they can. In everyday life, with all

of our decision-making, we adapt based

on circumstances and what we learned

last time. Over time, anyone using an

insulin pump could build up a library of

meals. If you tell it, tuna sandwich, and

you have tuna sandwich once a week,

you'll soon get a fairly clear picture of

what a tuna sandwich does to your blood

glucose, especially if most people use the

same bread type and stick to roughly the

same size sandwich. From that, it ought

to be possible for adaptive bolus advice

to be available based on other variables,

such as whether it's a weekday or

weekend, whether you've done exercise

or had alcohol."

Part of the current research being

done with the BiAP is based on the system

continuing to learn. It needs at least six

weeks of data to give optimal feedback

so that it is adaptive and personalised. At

present, all other boluses types in other

insulin pumps are based wholly on carb

counts.

"We've done a feasibility study using

an iPhone," says Oliver. "It was much liked

by the people who used it. The six-week

study had just 10 people, but with just that

small study group all glucose parameters

were improved - HbA1c, time in range,

and post-prandial blood glucose. At the

moment we're calling it ABC4D, which

stands for advanced bolus calculator for

diabetes."

Count us in

ABC4D takes into account not only

glucose but also meal absorption which

can be affected proteins and fats.

Continues Oliver, "Calculating the protein

and fat content of meals and altering

insulin requirements all of the time would

be just too hard for anyone. ABC4D

relies on consistency, rather than being

accurate so the more frequently you have

certain meals the better it will learn from

how your body reacts to that meal."

The current study, integrating ABC4D

with an artificial pancreas, uses the

Dexcom G5 CGM sensor. This data

goes via Bluetooth to the artificial pump

controller, in this study it's a smart phone

using ABC4D. This information goes over

to a Tandem T:Slim** insulin pump. Oliver

clarifies, "That's the architecture of the

system, but you use the mobile phone to

run the artificial pancreas. The latest study

we are running has three arms: a sensor

augmented pump, an artificial pancreas

with a rule-based bolus calculator, and an

artificial pancreas with ABC4D. All people

on the trial will end up doing all three of

these studies, six weeks on each with

a two week break between when they

go back to their old treatment regimen,

before going on to the next part of the

study. That should give a good indication

as to which of those three options brings

about the best blood glucose control, and

which the participants find most useful

and easy to use."

Research on the BiAP*** is set to

continue for a few years yet, as with

all artificial pancreas systems. In the

meantime, Oliver advises, "No matter

what, technology is not a replacement for

education. Keep learning about diabetes

and how you can best manage yours by

keeping informed about technological

improvements."

TheGuardian_ChrisToumazou

*Genomics - the study of genomes (a full set

of chromosomes, all the inheritable traits of an

organism).

What is the BiAP?

The Bio-Inspired Artificial Pancreas (BiAP) is worn externally and combines a

continuous glucose monitor that reads the user's interstitial fluid sugar level.

It also has an insulin pump that infuses the insulin into the body. The most

innovative element is the biologically-inspired microchip which uses an algorithm

to combine the CGM data with the pump's capacity to infuse insulin. This has

enabled the research team to replicate the activity of the beta cells of the

pancreas using integrated circuits on a silicon microchip. With this they have

been able to "deliver insulin profiles expected from a healthy pancreas".

Index

  1. Desang diabetes magazine diabetes information
  2. Abbott Freestyle Libre, Flash Glucose Monitoring, blood testing without lancets
  3. Desang diabetes magazine diabetes information, Sue Marshall
  4. diabetes news, novo nordisk insulin fiasp
  5. diabetes news, Medtronic, Medtronic Guardian Connect, BiAP
  6. diabetes news, Dr John Fossey, glucose
  7. Novo Nordisk diabetes mealtime management
  8. diabetes care, pocket medic, Kimberley Littlemore, Type 2 diabetes
  9. diabetes care, pocket medic, Kimberley Littlemore, Type 2 diabetes
  10. Ten Acre crisps, Jacob's Crackers
  11. A1C self check, HbA1c, Sweet Freedom
  12. Jean Cazels photography, British sandwiches, Heinz Seriously good mayo
  13. Ascensia Contour Diabetes blood test meters
  14. Accu-Chek Mobile blood glucose system
  15. Accu-Chek Mobile blood glucose system
  16. Redring tea survey, The Tea Terrace,
  17. Ecoffee, Costa Coffee
  18. Sue Marshall diabetes Professor Nick Oliver Imperial College London
  19. Professor Nick Oliver Imperial College London, BiAP, bio-inspired artificial pancreas, ABC4D, Chris
  20. Dr Philip Toleikis, Sernova, Cell Pouch technology, islet cell transplants, glucose responsive techn
  21. Dr Philip Toleikis, Sernova, Cell Pouch technology, islet cell transplants, glucose responsive techn
  22. Making Carbs Count, greek yoghurt
  23. Making Carbs Count, greek yoghurt
  24. Accu-Chek Insight insulin pump, making carbs count
  25. Accu-Chek Insight insulin pump
  26. Free diabetes magazine, Desang diabetes magazine,

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