LIVINGLIVING
leap of faith - for so long users have been
encouraged to run their own diabetes,
blood testing, carb-counting, bolusing.
Diabetes is a very hands-on experience,
and requires constant attention. The
MiniMed 640G is both similar but
different. With the MiniMed 670G you
have to take direction from the system as
it will tell you to test your blood glucose
and when to calibrate, and on occasion
it will suggest that you do a bolus. The
best thing you can do, is to do what it
tells you to, and don't do anything beyond
that. Understandably, it is hard to give
over control to a bit of technology, but it
does adapt to you and to your version of
diabetes. Don't try and second-guess it.
You have to trust it and take your hands
off the wheel a bit."
Work experience
So how does it work? The components
of the system are: The all new Guardian
Sensor 3 glucose sensor, the Guardian
Link 3 transmitter; an infusion set; a blood
glucose meter; Carelink software; and the
MiniMed 670G pump with SmartGuard
technology.
Simple things are set up in the pump
at the start by the user, under the care
of a healthcare professional, including the
person's insulin-to-carb ratio and active
insulin time. Then there is a three-day
period where the pump is on the person
but the SmartGuard Auto Mode is off (it
reverts back to the same functionality as
the MiniMed 640G system).
Once SmartGuard Auto Mode is
turned on, a reading is taken every five
minutes by the Guardian Sensor 3 CGM
sensor. Based on this the dynamic
SmartGuard Auto Mode algorithm in the
pump makes changes to the user's basal
rate, adjusting either up or down in order
to keep the glucose level stable. Every 24
hours at midnight the pump resets based
on what has happened the previous day.
Speaking further about the MiniMed
670G system, Medtronic's EMEA Marketing Manager Andrew Nicholson
says, "This cutting-edge technology
delivers improved glycaemic control whilst
allowing the person to hopefully think less
about their diabetes. With the MiniMed
640G system the focus had been on
preventing lows; with the MiniMed 670G
we are addressing the highs as well as
lows. When in SmartGuard Auto Mode,
the system adjusts to the persons real
time glucose needs by giving small
amounts of basal insulin every five
minutes as the system targets a glucose
level of 6.7 mmol/L.
All the range
Referring back to time in range (TIR),
this is a more modern way of measuring
diabetes control, made possible in the
main by the evidence supplied by the
use of CGM sensors and expressed as
a percentage: the percentage of time
someone with diabetes spends within the
optimal range of above 3.9 mmol/L and
under 10 Mmol/L. Studies have shown
that people using multiple daily injections
(MDI) spend on average 45% of their time
in range. It has to be noted that these
studies tend to be based on people with
diabetes who have fairly good control,
so others on MDI might not achieve that
number. Those using an insulin pump
have been shown as having 51% time
in range, and those using a sensor-andpump combination achieving an average
of 57% time in range.
Says Cohen, "We think you deserve
better than this. We are trying to move
people to better control by improving
time in range as well as HbA1c. The way
you run your diabetes currently takes a lot
of effort, don't underestimate how much
you know, and how much it is that you
do to control your diabetes. Our hope is
that you will have to think less about your
diabetes. Time in range is a more modern
metric, thanks to the increased use of
CGM sensors over recent years. It's really
about time in 'ranges' - less time low, less
time high, more time in the middle. The
great news is that users of the MiniMed
670G system in clinical trials in the US
have been proven to be spend an average
of 72% time in range. Our hope is to get
the amount of time spent in range even
higher than that."
www.medtronic-diabetes.co.uk
""The algorithm that is inside
the MiniMed 670G system
has taken a decade to figure
out. It has involved engineers
with specialisms in applied
mathematics and theoretical
physics. This was no trivial maths
problem." - Dr Ohad Cohen,
See following pages for a glossary of terms used in this
article as well as a refresher on the idea of time in range.