Hi-tech sensors that can use smells to detect when you’re unwell

The latest medical tools to diagnose your illness rely on your smell. If that sounds odd just think for moment. Can you recognise your partner, your mum or dad from their smell?

Their smell depends on their body chemistry and everybody’s chemistry is unique. When that chemistry goes wrong their smell changes, not so you’d notice probably, but the latest technology can detect those small variations.

Each of us has a unique odour print made up of thousands of organic chemicals. These molecules offer a whiff of who we are, revealing age, genetics, lifestyle — even the metabolism that underlies our health.

We’re not the first to use a patient’s scent to make a diagnosis. The ancient Greeks did. Modern medical research confirms that the smell of someone’s skin, breath and bodily fluids can be suggestive of illness.

Dramatic examples are the breath of diabetics, which sometimes smells of pear drops and the skin of typhoid patients, which smells of baking bread.

For decades researchers have been trying to build a cheap odour sensor for quick, reliable and non-invasive diagnoses.

Now Billy Boyle, co-founder of Owlstone, a manufacturer of chemical sensors in Cambridge thinks his breakthrough technology can be a useful tool using odour analysis. The NHS is funding a 3,000 strong clinical trial to test Owlstone’s sensor to diagnose lung cancer.

The sensor is a silicon chip that looks like a mobile phone SIM card.

It works like a chemical filter.

“You can program what you want to sniff out just by changing the software,” says Boyle. “We can use the device for our own trials on colorectal cancer, but it can also be used by our partners to look for other things, like irritable bowel disease.”

The company is conducting a 1,400 patient trial with Warwick University, to detect colon cancer from urine samples, and is exploring whether its chips can help determine the best drugs for asthma patients by sorting through molecules in their breath.

A similar diagnostic technology is being developed by an Israeli chemical engineer, Hossam Haick, a professor
at Technion-Israel Institute of Technology in Haifa using biomarkers of disease found in exhaled breath.

“We send all the signals to a computer and it will translate the odour into a signature that connects it to the disease we exposed to it,” Mr Haick said.

Using artificial intelligence, Haick says, the machine becomes better at diagnosing with each test. Rather than detecting specific molecules that suggest disease, however, Mr Haick’s machine sniffs out the overall “chemical stew” that makes up an odour.