Scientists at Huazhong University of Science and Technology (HUST), in Wuhan, China, have created a new type of gel-based sensor that can be implanted in the brain. This tiny sensor, which is about the size of a grain of sand, is soft and can dissolve in the body in a little over a month. The aim of this new biodegradable sensor is to help monitor the health of people with head injuries or cancer.
This gel-based sensor can be placed in the body without needing any invasive surgery and it works completely wirelessly. When tested on rats and pigs, the sensor performed just as well as traditional wired sensors. It can track important health indicators, such as temperature, pH levels and pressure.
According to Yueying Yang, a biomedical engineer at HUST, this technology will, possibly, be very helpful for people in medical settings—such as hospitals, clinics, and doctors’ chambers, says Interesting Engineering media house.
The study has left little to chance, Christopher Reiche, who develops implantable micro-devices at in Salt Lake City’s University of Utah, was quoted by Interesting Engineering as saying. Most sensors now rely on wires to send data to doctors. These wires are difficult to insert and remove and can create openings in the skin that allow viruses and bacteria to enter the body. Wireless sensors are an answer to this problem, but their relatively large size and limited communication range have been a constant obstacle.
To address these problems, Yueying and her team designed a set of small cube-shaped sensors, measuring only 2 millimetres, using a soft and flexible material, called hydrogel. Hydrogel is commonly used in medical applications, such as tissue regeneration and delivering medications. These gel sensors change their shape when exposed to different temperatures, pressures and levels of acidity in their surroundings.;
Additionally, they can detect vibrations caused by fluctuations in blood flow in the brain. By scanning the area with an ultrasound probe, medical professionals can analyse how ultrasound waves passing through the skull from the sensor are altered due to pressure, pH, or temperature fluctuations.
The small gel cubes dissolve fully in a saline solution in roughly four months’ time and break down within the brain in five weeks. Experiments on rats and pigs revealed that these sensors could detect tiny changes in pressure and temperature as effectively, if not more so, than traditional sensors.
For instance, the sensors could detect tiny changes in skull pressure caused by a pig’s breathing, which wired probes cannot as accurately. These findings are impressive, thinks Julia Körner, who develops hydrogel-based medical sensors at Leibniz University, in Hannover, Germany. However, she says more research is needed to ensure that the sensors are safe for humans.
The primary worry is whether the byproducts from the sensors breaking down may be harmful or build up in other parts of the body. Yueying mentioned that they would keep studying the safety of their system. They also aim to improve the sensors for reliable long-term use and look into mass-producing the devices.
