A team of engineers at the Texas Analog Center of Excellence (TxACE) at UT Dallas is working to develop an affordable electronic nose that can be used in breath analysis for a wide range of health diagnoses. Existing devices built with compound semiconductors can conduct breath analysis, but they are bulky and too costly for commercial use, said Dr. Kenneth O, Professor of Electrical Engineering and Director of TxACE. The researchers determined that using complementary metal-oxide-semiconductor (CMOS) integrated circuit technology will make the electronic nose more affordable. (See Figure 1) CMOS is the integrated circuit technology used to manufacture the bulk of electronics that have made smartphones, tablets, and other devices possible.

Fig.1 – Researchers determined that using CMOS integrated circuits, including the one shown to the right of the U.S. quarter and below the label “CHIP1,” in an electronic nose will make the device more affordable. (Credit: UT Dallas)

“Smell is one of the senses of humans and animals, and there have been many efforts to build an electronic nose,” said Dr. Navneet Sharma, a researcher at UT Dallas. “We have demonstrated that you can build an affordable electronic nose that can sense many different kinds of smells. When you’re smelling something, you are detecting chemical molecules in the air. Similarly, an electronic nose detects chemical compounds using rotational spectroscopy.”

How It Works

The rotational spectrometer generates and transmits electromagnetic waves over a wide range of frequencies, and analyzes how the waves are attenuated to determine what chemicals are present, as well as their concentrations in a sample. The system can detect low levels of chemicals present in human breath.

Breaths contain gases from the stomach, and also gases that come out of blood when it comes into contact with air in the lungs. The breath test is essentially a blood test without taking blood samples. Breath contains information about practically every part of a human body.

The electronic nose can detect gas molecules with more specificity and sensitivity than Breathalyzers, which can confuse acetone for ethanol in the breath. The distinction is important, for example, for patients with Type 1 diabetes who have high concentrations of acetone in their breath.

“If you think about the industry around sensors that emulate our senses, it’s huge,” said Dr. O, who also holds the Texas Instruments Distinguished University Chair. “Imaging applications, hearing devices, touch sensors—what we are talking about here is developing a device that imitates another one of our sensing modalities, and making it affordable and widely available. The possible use of the electronic nose is almost limitless. Think about how we use smell in our daily lives.”

The researchers envision the CMOS-based device will first be used in industrial settings, and then in doctors’ offices and hospitals. As the technology matures, they could also become household devices. Dr. O said the need for blood work and gastrointestinal tests could be reduced, and diseases could be detected earlier, lowering the costs of health care.

The researchers are working toward construction of a prototype programmable electronic nose that can be made available for beta testing sometime in early 2018.

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