2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Dutch startup NovioSense has developed an effective way to measure glucose in tears. The sensor in the form of a small tube is coated with biopolymers, which contains an enzyme that responds to an increase in the proportion of glucose. The effectiveness and convenience of this device has been tested on rabbits, sheep and six humans. The IEEE Spectrum portal drew attention to the novelty.
People with diabetes need constant monitoring of their blood sugar levels. This is usually done by taking blood from a fingertip and then testing it with a blood glucose meter, but this method may not be very convenient. For a long time, the American startup Verily, owned by the Alphabet holding, together with Alcon, has been developing a sensor for non-invasive glucose measurement. Their device has the shape of a contact lens and measures the glucose level not in the blood directly, but in the tear: the fact is that the composition of a tear, like the composition of blood, depends on various factors and changes with an increase in glucose levels. Recently, it was reported that Verily and Alcon have suspended the development of the sensor: engineers have not been able to achieve the necessary accuracy, allowing you to compare the level of glucose in a tear with its level in the blood.
Dutch startup NovioSense has managed to create a sensor that effectively measures the glucose level in tears. Unlike all previous developments, it is not in the shape of a lens, but in the shape of a small tube that is located under the lower eyelid. Such a device is much more effective than a lens: the tube is located near the lacrimal canal, which makes access to the constantly secreted tear easier and does not require additional stimulation, as is the case with lenses.
The tube is covered with polysaccharides, the enzymes in which react to changes in the level of glucose in the blood. The reaction, consisting in the oxidation of hydrogen peroxide, transmits a signal to the electrodes, which, in turn, report the change in glucose levels to a special transmitter: for now, the technology is wired, but soon the engineers plan to start wirelessly transmitting data from the sensor to the device.
NovioSense has already conducted clinical trials with the participation of six volunteers: before that, it was also tested on rabbits and sheep (in particular, in order to make sure that the sensor is comfortable. Despite a small sample (scientists will need to increase it in the future), the engineers succeeded to show the effectiveness of the device they developed: the level of glucose measured in tears coincided with the level of blood glucose in 95 percent of cases. The results of their work, as well as the sensor design are also detailed in an article published in the journal Biomacromolecules in October.
Another method of non-invasive monitoring of blood glucose is a special tattoo made of ink that changes color when the composition of the blood changes. This ink was created last year by scientists at the Massachusetts Institute of Technology.
