LIVINGLIVING
KIT THAT'S COMING SOON
MICRONEEDLE CGM
This concept is being worked on at Imperial College London.
I talked to Dr Monika Reddy about the project and how it's
different from other CGM solutions. By Sue Marshall
A
t At Imperial College
London as part of
diabetes research
projects there are several
technology solutions
being undertaken by Professor Nick
Oliver and his team. As part of this team
Dr Monika Reddy has been working
on one project in particular looking into
microneedle CGM.
Reddy explains, "We work closely with
a small team of chemical and biomedical
engineers to further ideas that can
potentially improve control and quality of life
for people with diabetes. Currently people
with Type 1 diabetes and Type 2 diabetes
treated with insulin are encouraged to
do finger-prick blood testing four times
a day. More recently we've been able to
recommend CGM to individuals at high
risk in line with NICE guidelines. However,
virtually all current CGM involves sensors
placed directly into the skin, with a needlelike filament
that is placed subcutaneously
into tissue. There are some downsides to
this method, including some discomfort,
the fact that it can lead to a reduction in
sensor accuracy over time and when
blood glucose is low (hypoglycaemia).
Subcutaneous CGM does not use capillary
blood but interstitial fluid, and that means
it can be slightly behind the accuracy of
capillary blood test results, as much as 15
minutes behind."
So, can there be an improvement
in the technology to get all the benefits
of subcutaneous sensor CGM but
with greater accuracy, and what about
ease-of-wear too? Says Reddy, our
microneedle CGM concept still uses
the same chemical - glucose oxidase
- as used in other CGM systems, but
instead of using one filament it consists
of a small wearable patch containing a
series of very small spikes or needles that
penetrate only the outermost skin layer.
By using several spikes you get more
than one glucose measurement, which
can improve accuracy. Current CGM
solutions cost around £150 a month,
and this is a cost that limits the ability of
HCPs to recommend it to all people with
Type 1 diabetes. We are working on a
microneedle CGM that should be more
affordable as well as more accurate."
Getting the needle
I don't know about anyone else, but while
CGM can bring its own problems - you
can knock them off, they can cause
bleeding and some discomfort at insertion
and get a bit itchy, but in the main they
are not painful. I'm not sure I'm liking the
sound of 'a series of small spikes'. But
hold on, how this would feel to wear
has been a key point in designing the
solution. "We not only want to push this
technology forward in order to improve on
Dr Monika Reddy