Waiting for a ‘smart’ toilet? It’s nearly here

Gathering health data with every flush, some toilets might learn you’re sick before you do

What exits the body and ends up in the toilet could tell you and your doctors a lot about your health — if the toilet were smart, that is. Some now under development could help diagnose disease.

K_Thalhofer/iStock/Getty Images Plus

Think back to the last time you pooped. Was it hard or soft? Was it dark or light brown? Was there corn in it? You might find these questions uncomfortably personal. Yet the wastes our bodies shed can say a lot about our health. And it can be hard to remember past poops and pees well enough to describe to doctors once we realize that we’re sick. There’s also a lot of stuff in those wastes not visible to the eye. But new technology can help. You can just think of these systems as smart toilets.

They gather health data by analyzing poop and pee so you don’t have to. Scientists hope that one day such toilets will be able to diagnose cancer and viruses. In fact, scientists are already using human feces (although not via toilets) to track the COVID-19 virus.

But that’s for the future. The smart toilet being developed at Stanford University in Palo Alto, Calif., can’t do nearly that much. The prototype can take pictures of your feces, track how often you go and measure how long each poop takes. Artificial intelligence then evaluates the consistency of the poop using a so-called Bristol scale. (Its seven categories range from “rabbit droppings” through sausage-shaped to “gravy.”) The toilet also can measure the number of white blood cells and types of protein in urine. Such information could indicate an infection of the urinary tract or bladder.

Seung-min Park is a biomedical engineer working on the project at Stanford. Data on stool consistency can help patients with irritable bowel syndrome (IBS), he says. IBS patients need to monitor what their poop looks like over time. This toilet can do that for them.

The data gleaned will move through the internet to a secure computer. An artificial-intelligence program then will assess the data. If it finds a problem, the program can notify a patient’s doctor.

Sonia Grego is an electrial and computer engineer leading another smart-toilet project at Duke University. It’s in Durham, N.C. When it comes to medicine, Grego says, human wastes “are an untapped resource.”

Potty confidential

As a toilet collects health data, those data must be linked to the right person. But how is the toilet to know that you are the one on the seat and not your brother, parents or some visiting guest? Right now, there’s a camera.

Everyone’s anus has unique curves and other patterns. It’s distinct, like a fingerprint. Those patterns can be used to identify who sits on a toilet.

a diagram showing a smart toilet and the various sensors it uses
This diagram of the current Stanford prototype shows how the toilet evaluates poop and captures the user’s unique anal print.Adapted from S. Park et al/Nature Biomedical Engineering 2020 and Gambhir lab’s drawing

Park and his team chose to have their toilet use a scanner to image those patterns. This doesn’t require that people who use the toilet do anything special. Just sit down on the seat, as usual. An image of the butt will later be used to identify data obtained from that person’s toilet visit.

Engineers loved this ID system. Potential users, not so much. “They didn’t want to have a camera underneath their butts,” Park says. So on the next model, his team will replace the camera with an infrared or laser scanner. That scan’s output won’t look like a photo.

Another type of “smarts”

At Duke University, Grego’s team is working on an alternative model. It waits to analyze wastes as the toilet bowl’s water is flushed away.

The team working on this project also wants to keep a user’s experience as normal as possible. They haven’t started thinking about an identification system yet, but Grego says this device won’t take pictures of any body parts.

“I think we would identify an individual the same way as other systems would,” she says. She’s referring to technology for facial recognition and fingerprint IDs.

Scanning one’s privates is hardly the only privacy issue with smart toilets. What comes out of your body says a lot about you, or at least about your body. Such data can help doctors track your health. But that data also could be misused by insurance companies or others. And some toilets might one day be able to test your DNA. Those genetic data may have details you don’t want to share with anyone — perhaps not even with yourself.

Park appreciates such privacy concerns. However, he also thinks the benefits may outweigh the risks. “The more you expose your privacy,” he believes, “the better the health care.”

Grego and her team at Duke are hoping to have a toilet that can be tested by people within the next two years. Park says his team will come out with its next version within the year. Their eventual goal is to be able to isolate RNA or DNA, details that could detect cancers and viruses.

“We want to measure everything that can be extracted from the human body over a lifetime,” he says.

a researcher working with the Smart Toiled in the lab
A member of the Smart Toilet research team tests its technology using a regular toilet on a research bench.Duke Center for WaSH-AID

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