Diabetes prevalence is rapidly increasing in the world. The number of people with diabetes has risen from 108 million in 1980 to 422 million in 2014. Considering the size of the problem, you must all have seen or maybe used a glucose monitor. So, how does it work?
Blood glucose level is kept in check in the body by a hormone called insulin, produced by the pancreas. Unstable insulin levels in blood may cause excess glucose to be converted to fat and be deposited on your blood vessels as plaque. This may cause various complications such as cardio-vascular disease, nerve damage, kidney damage, eye damage among a lot of other complications.
Why should I know my glucose level?
- To know whether the steps you take, are keeping the glucose levels under control.
- To take action accordingly if glucose level is too low or too high.
Design of the Glucometer:
When blood is placed in the sample region of the strip and inserted into the device, the enzyme (Glucose oxidase) reacts with the glucose and current flows in the electrode sensing circuit. The current is converted to a voltage using a current-to-voltage converter (Trans-impedance amplifier). This voltage is compared to a reference and the output voltage is displayed. A micro-controller is present on the circuit to do the required computations and to drive the display circuit. As glucose concentration in blood increases, the current also increases in the circuit.
Some precautions need to be taken so that the glucose measurement is accurate. Washing of hands before pricking, using fresh or recently bought test strips, measuring glucose at proper intervals are the most important things. Humidity, Temperature may also play a role in the storage of the test strips.
Measurement of glucose non-invasively is developing rapidly. Several methods have been attempted to measure glucose non-invasively and so many devices are in the development stage.
- Gluco-wise is currently in development and it extracts glucose level by transmitting low power radio waves in between fingers to obtain glucose levels.
- SugarBEAT is a device (also in development) that measures glucose level from body’s interstitial fluid from skin. It is a small disposable patch that can be stuck on to the arm.
- GlucoTrack is a similar device that uses 3 technologies (ultrasonic, electromagnetic and thermal) to measure glucose levels non-invasively.
Recently MIT researchers have developed a colour changing tattoo ink that responds to changes in blood sugar levels. Interstitial fluid in the skin come in contact with the tattoo ink and the glucose level can be indicated. However, some of these promising techs have not yet reached the market. The researchers and the patients hope to end the pricking business as soon as possible.
Sources & References
Image source – https://goo.gl/tPcHF2
Image source – https://goo.gl/4v6TUK
Video – How does Glucometer work – https://www.youtube.com/watch?v=Evw5AqUYJcg
Glucose meter reference design – https://goo.gl/V45Xkh
MIT colour changing tattoo – https://goo.gl/OhzaMG
WHO factsheets – https://goo.gl/jlVLK