September 18, 2023 – The race to “sniff out” diseases in human breath has begun.
Hundreds of breath analyzers that detect odors links attached to Cancer are in development, but only a handful have reached the market or are in clinical trialsSome of them, colloquially known as artificial or electronic “noses,” mimic biological systems.
The latest platformby researchers at Seoul National University in South Korea contains a microchip that enables a pc to “smell” spoiled food. Unlike previous artificial noses, this one is more compact and energy efficient.
“The most important improvement is that they have implemented some calculations on the chip. This is extremely useful,” said Debajit SahaPhD, assistant professor of biomedical engineering at Michigan State University, who was not involved within the study. The design eliminates the necessity for a separate computing device, thus saving energy.
“For applications like food safety, where recurring measurements need to be taken, lower energy consumption is good,” Saha said.
How scientists are developing technologies that may smell
This technology, referred to as artificial olfactory systems or AOSs, first appeared within the 1980s. In a typical AOS, sensors collect analog data that should be converted to digital data by separate computing devices before being transmitted to a processor that calculates gas concentration. However, this process is time- and energy-intensive, and data could be lost during transmission.
The researchers developed a chip or sensor unit that collects information And converts only the essential data, with no separate computing device. The platform could eventually be paired with smartphones and deliver results wirelessly.
“For the AOS to be applied to various non-plugged devices such as mobile phones, small size and excellent energy efficiency are essential,” said Co-author of the study Jong-Ho Lee, PhD, professor of electrical and computer engineering at Seoul National University.
The sensors are powered by low-power micro-heaters and have thin zinc oxide movies that may detect traces of hydrogen sulfide and ammonia gases, the telltale signs of spoilage in protein-rich foods.
To test the platform, the researchers placed chicken in a container that they connected to eight sensors. They then injected dry air into the container containing the meat. The system constantly tracked emissions and calculated gas concentration levels to point spoilage.
The platform is “highly customizable,” said Lee, who envisions future applications in healthcare, including “disease monitoring through human breathing.”
Odor detectors: the longer term of cancer diagnosis?
Cancer cells give off volatile organic compounds, chemicals that smell and may function biomarkers for diagnosis. Although the factitious nose has the potential to specifically detect these compounds, more work is required to make this a reality.
At this stage, the platform can only detect two chemicals and measure gases in ppm. To detect cancer and other diseases, it will need to answer “many” different chemicals and calculate gas concentrations in ppm. billionSaid Saha.
Very few electronic noses are that sensitive. “The biological smell system is still superior,” Saha said. “That's why you still see dogs at the airport and no devices to test for explosives and drugs.”
His lab takes a unique approach, using living insect brains and antennae to create an “all-in-one device” for gas detection and calculation.
“It is an open question how to make chemical sensors more robust, reliable and sensitive. Our approach is to hijack the biological brain to do the work for us,” Saha said.
His laboratory has discovered oral cancer with Locusts. And recently, they're using neural signals from honey bees to detect lung cancer. This research may soon be published.
So far, this research has used cell cultures containing cancer biomarkers, however the lab plans to check its approach using human breath.
Lee and his colleagues also hope to expand their research by “combining a neuromorphic system that mimics the human brain with an artificial olfactory system.” Ultimately, it could detect a big selection of gases and thus be useful in quite a few fields.