Researchers in Germany and The Netherlands have developed a tiny wireless
biosensor that could eliminate the need for blood testing for
The researchers at the Fraunhofer Institute for Microelectronic Circuits and
Systems (IMS) in Duisburg, Germany, worked with Dutch medical firm Noviosens to produce a
low power biosensor for blood glucose that combines measurement and digital
analysis with both an RF link and can be powered by RF energy in the
For many diabetics checking blood glucose is an everyday part of
life, especially for patients with Type-1 diabetes who always have to keep a
close eye on their levels as their bodies are incapable of producing the insulin
to break down the glucose in the blood. Several times a day, they have to place
a tiny drop of blood on a test strip. It is the only way they can ascertain the
blood glucose value, so they can inject the correct amount of insulin needed.
And this pricking is not only a burdensome: it may also cause inflammation or
cornification of the skin.
The biosensor avoids this as it is located on the
patientís body and is able to measure glucose levels continuously using tissue
fluids other than blood, such as in sweat or tears.
The measurement involves
an electrochemical reaction that is activated with the aid of an enzyme. Glucose
oxidase converts glucose into hydrogen peroxide (H2O2) and
other chemicals whose concentration can be measured with a potentiostat and this
measurement is used for calculating the glucose level.
The 0.5-mm by 2.0-mm chip
includes the nanopotentiostat and the diagnostic system. "It even has an
integrated analog digital converter that converts the electrochemical signals
into digital data," said Tom Zimmermann, business unit manager at IMS. The
biosensor transmits the data via a wireless interface, for example to a mobile
receiver. Thus, the patient can keep a steady eye on his or her glucose level. "In the past, you used to need a circuit board the size of a half-sheet of
paper," said Zimmermann. "And you also had to have a driver. But even these
things are no longer necessary with our new sensor."
required about 500-microamps at 5 volts; now, it is less than 100-microamps. That increases the
durability of the system Ė allowing the patient to wear the sensor for weeks, or
even months. The sensor is able to send and receive data packages, but it can
also be supplied with power through radio frequency.
The next stage is to
look at using the biochip to control an implanted miniature pump that, based on
the glucose value measured, indicates the precise amount of insulin to
administer. That way, diabetes patients could say goodbye to incessant
needle-pricks forever.This article originally appeared on EE Times Europe.Related links and articles:
Webinar on multicore virtualization in medical devices
News articles:Wireless display in a contact lens takes shapeElectronic contact lens debuts
ST makes contact lens MEMS to help with glaucoma