project I've been involved since 1997 is to develop and produce a new non-invasive glucose
main problems I had to face in this project are the following:
interference of electrical noise;
reproducibility of the measure;
positioning of the sensor.
problems are the same for everyone who wants to realize such devices.
The most promising technology used in new non-invasive glucose meters,
I think, is the detection of the electrical resistance of the skin and
the association to the glucose concentration in blood. In this case
there seems to be a high degree of noise resistance of the device. But
the reproducibility of this measure is quite affected by the fact that
the sensor must be positioned and then the machine must be set-up.
This procedure of initialisation which seems to be necessary to the device to work good
is no longer valid if the sensor changes its position. In this case how
can a patient be sure whether the sensor changes position or not? This
means that this device is not adapt to work during the night; but what
happens during the day? They say that if the sensor is good placed,
there is a certain percentage of good measure which is close to the
50%… but how can a patient be sure of what to do? The first question
I would make is : Am I in the right 50% or in the wrong 50%?
developed a new technology for these instruments and I have two
working devices that are suitable to understand how can be faced each
of the upper problems with this new technology.
of the two devices must be applied to the ear, in fact there is a
relationship between some specific physical parameter detectable just
internally the ear and the blood glucose levels.
first instrument is composed by:
sensor head that is quite insensible to noises;
to visualize the situation;
first instrument is suitable just for an initial survey. While it’s
very much insensible to electrical noise it lacks of a
good positioning, which is important if we want to reach a good and
repetitive measure. When the measure starts it’s evident (and it's
possible to feel it) that maybe the device is making some mistakes, instead of a good
measure! After many measurements in a single patient I’ve found a
position of compromise and completed a table of values, taken in
always this position, but in different glycaemic situations. At the
end of these tests I had always the same bad sensation to make some
mistakes, and this is the reason why I personally never would use a
sensor working at a 50% success rate.
second instrument is composed by:
quite smaller sensor head;
electronic pre-amplifier and signal conditioner;
to visualize the situation;
matter with the first-type instrument was the positioning of the sensor
head, that is the most common problem of the latest non-invasive
I’ve made the second-type instrument to better face the problem with
the positioning. In fact, the behaviour of this instruments is just to compensate the bad positioning.
In this case there is another table and a further calculation (by hand,
at the moment) to reach the good measure.
this case I didn’t care of the noise-resistance (and this device is
quite delicate with electrical noise). This new system is quite more
reactive to the changing of the glycaemic values: it can appreciate the changing of the glucose concentration
in blood with only a delay of 15-30 seconds.
next step (to do…) will surely be to build up a new instrument which
sums the good characteristics of the two upper systems.
the device is not capable to give a numeric result (as a standard
instrument gives) in automatic, the software must be upgraded in this
there is not a filter in the software right now, to avoid electrical
noise it could be useful to build up one.
these devices have been tested only in one patient,
it could be reasonable to start with a wide ranged campaign of tests.
what I can imagine, it would be easy to realize this device even in
cellular phones or palmtop and when there is something wrong it would
ring or vibrate…
the sensor is hand-made, it is surely important that it is engineered.
Maybe, and I say maybe, it can be build up with a wireless technology…
could be an improvement because the positioning must be in the ear.