A Blood Test at the Touch of a Button, Without the Needle

Tara Haelle

November 15, 2022

The blood test is one of the most common medical labs performed to understand what is going on with a person's health. But the test requires taking blood with a needle, which only trained health care professionals can do before sending the sample off to a lab for analysis.

Now, researchers have developed a new method to test blood composition after a single touch of a person's finger (which is good news for the high number of people who fear needles). 

With funding from the National Science Foundation, researchers from Stanford University and the University of California at Los Angeles developed a hydrogel-coated chemical biosensor that collects molecules on a person's skin that are released through sweat. By analyzing these molecules, the biosensor can detect hormones, nutrients, medications, and metabolites in an individual's blood.

The researchers call their system "a cryptographic bio-human machine interface," and it collects heart rate and blood oxygen levels as well, just as a pulse oximeter does, they report in the  Proceedings of the National Academy of Sciences.

To protect privacy, the system can also encrypt data it collects at the point of contact, using the person's fingerprint as the key in the same way some smartphones use fingerprints to unlock them.

This technology may one day be used to check a person's medication levels or monitor blood sugar. It could also be used to for drug testing or to replace a breathalyzer to stop people from driving while intoxicated.

Biosensors could be embedded into steering wheels of keyless cars to measure blood alcohol levels and the presence of other drugs and stop the vehicle from being driven by someone under the influence of alcohol or drugs.

"This combines the familiarity of a fingerprint scan with our advances in noninvasive diagnostics that can detect trace molecules circulating in our body that have been traditionally collected in samples of blood, saliva and other fluids," said Sam Emaminejad, PhD, one of the scientists from UCLA.


Proceedings of the National Academy of Sciences: "A touch-based multimodal and cryptographic bio-human–machine interface."


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