26KIT
KIT THAT'S COMING SOON
Afon Technology noninvasive
CGM sensor
Introducing his technology at a
recent online diabetes event,
Afon Technology founder Sabih
Chaudhry referred back to a
research paper written in 2006 by
Doctor of Philosophy John Smith.
His paper was entitled The Pursuit
of Non-Invasive Glucose: Hunting
the Deceitful Turkey, the turkey
reference being taken from a Mark
Twain short story that asks many
questions but has few answers.
Also in 2006, a non-invasive
diabetes product called GlucoWatch
was developed by a company called
Cygnus, which was subsequently
taken over by Animas ¬- part of
Johnson & Johnson - but the product
development stalled and came to
nothing (for more info, see below).
That fact has not put Chaudhry
off his pursuit of this deceitful
turkey. He explains, "The fact is that
it's a challenging - but emerging -
technology. It involves photonics,
sweat and electrophoresis [see
glossary]. But there is scope to
develop these products as there are
known downsides to the currently
available sensors ¬- questions
of accuracy, sensitivity and the
potential for an allergic reaction to
the adhesives needed to stick sensor
onto skin."
Afon Technology is using radio
and microwave frequencies (multiresonance),
which are both on
the long wavelength end of the
Electromagnetic Spectrum, to read
blood glucose levels via a noninvasive
sensor. That's to say there's
no 'pokey' bits stuck in the body;
the sensor just sits on top of the
skin unlike what might be called
'traditional' CGMs where the skin is
punctured to allow a sensor to be
inserted into interstitial body fluid to
read glucose levels.
Wild goose chase?
In 2005, Chaudhry had been
undertaking scientific investigations
in a laboratory in Bangor University,
later raising money to continue
to research into the possibility of
designing such a sensor. In 2012, a
trial at the Royal Liverpool Hospital
showed the microwave factor. In
2015, additional funding allowed
him to stop being a one-man band;
he started the company which now
has a lab in the Wye Valley with a
team of researchers and engineers
pushing the technology forwards.
Chaudhry says with a small smile
that, "Things can work wonderfully
'on the bench', but on the body there
are the challenges of movement, the
changing condition of the skin - and
so forth. We took a step back to ask,
what are we trying to do, and how?"
After taking the time to restrategize,
he and his team felt
that they were going to be able
to develop a colour-indicator as
part of the device, showing yellow
for hyperglycaemia, green for in
range and red for a hypo. It would
also indicate Time-in-Range
measurements, increasingly TIR
is seen as an extremely powerful
enabler of self-management for
anyone living with diabetes.
The design of the sensor is such
that it would be worn on the wrist,
potentially on a watch or just on any
other wrist-strap. Being worn on the
wrist means it could be prone to a
jarring shock if knocked, therefore
it needs to be robust, but people are
already using watches, so integrating
the sensor makes a lot of sense. It
also means it does not have to be
another wearable device on the body,
while it will also be 'manufacturer
agnostic, being able to 'talk' to other
smart devices with electro-magnetic
compliance, such as smart phones.
Afon's sensor is likely to be the size of
two £2 coins, stacked on top of each
other and will last for two years.
A MARD measurement (mean
absolute relative difference*) is used
to assess the accuracy of both blood
glucose meters and CGM sensors. In
general, lower MARD values indicate
higher accuracy. At present, Afon's
sensor is coming in at 20% whereas
Dexcom's G5 came in at 10%.
Medtronic's Enlite sensor is anything
anything between 15% and 21%,
likewise Abbott's FreeStyle Libre.
Says Chaudhry, "The team has
multidisciplinary skills and is slowly
and systematically overcoming
barriers. We are planning to apply
Sabih Chaudhry