- Tight glucose control, using frequent glucose measurements to guide
the administration of insulin decrease the long-term complications of
diabetes but with a threefold increase in hypoglycemic events.2
- An automatic system could provide detailed information on glucose
patterns and trends in addition to an opportunity to sound alarms for
rapid declines in blood glucose values to reduce the risk of hypoglycemic
- Iontophoresis is a technique where a constant low-level of electricity
is conducted through the skin between an anode and a cathode. Positive
particles (ions) are attracted to the cathode. Uncharged particles,
such as glucose are carried along with the ions by convective transport.
As the skin has a negative charge at neutral pH, there is a greater
net transport to the cathode.
- At the cathode, glucose is broken down by glucose oxidase which causes
the oxidation of glucose to gluconic acid and hydrogen peroxide. The
hydrogen peroxide is then detected by its breakdown via an electrocatalytic
oxidation reaction to O2 + 2H+ + 2 electrons.
- The entire process takes 10 minutes: 3 minutes to collect glucose
and 7 minutes for the sensing mechanism to ensure all glucose, and subsequently
hydrogen peroxide, are consumed.
- Iontophoresis may be a superior choice to self-monitoring blood glucose
devices since it avoids large proteins, e.g. hemoglobin, which can currently
cause interference. The technique monitors peripheral tissue where
blood glucose utilization actually occurs.
- Other studies have shown that iontophoresis has produced acceptable
results for 95% of its measurements, comparable to that of currently
available blood glucose monitors.
- Other noninvasive techniques for blood glucose monitoring include
Far-infrared radiation, near-infrared radiation, radiowave impedance,
optical rotation of polarized light, and interstitial fluid harvesting.
Tamada JA, et al. Noninvasive glucose monitoring: Comprehensive
clinical results. Cygnus Research Team. Journal of the
American Medical Association, 1999; 282(19):1839-44.
The Diabetes Control and Complication Trial Research Group. The
effect of intensive treatment of diabetes on the development and progression
of long-term complications of insulin-dependent diabetes mellitus.
The New England Journal of Medicine, 1993; 329:997-1036.
Tamada JA, Bohannon NJV, Potts RO. Measurement of glucose in diabetic
subjects using noninvasive transdermal extraction. Nature Medical,