man sitting on toilet

Smart toilet’s ID tactics could leave users feeling exposed

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Stanford University researchers have developed a toilet fitted with a suite of gadgets for assessing the health of the user from their urine and stool samples. The toilet matches individuals with their datasets by scanning their anus for identification.

The health-focused smart toilet is capable of detecting disease markers in urine and stool, including for some cancers like colorectal and urologic cancers. It was developed in the laboratory of Professor Sam Gambhir over a period of more than 15 years and has now completed a pilot study of 21 participants, with the results published in Nature Biomedical Engineering.

According to Gambhir, a toilet is a good place for continuous health monitoring: “The thing about a smart toilet is that, unlike wearables, you can’t take it off. Everyone uses the bathroom – there’s really no avoiding it – and that enhances its value as a disease-detecting device.”

An ordinary toilet can be transformed into a smart toilet with the addition of a suite of gadgets fitted inside the bowl. These tools use motion sensing to begin a series of tests to assess the health of the user from their waste. Urine and stool samples are captured on video and processed by algorithms which can distinguish healthy and abnormal “urodynamics” and stool consistency. Urine samples also undergo molecular analysis via uranalysis strips; this can identify certain features useful for monitoring health, such as white blood cell count. At present, the toilet can measure 10 different biomarkers.

The toilet automatically sends de-identified data from the samples to a secure, cloud-based server for safekeeping.

It is important for the toilet to be able to distinguish between users in order to provide personalised health feedback, presenting the researchers with the challenge of deciding how best to discern between users. Although they began with a flush lever which reads fingerprints, they realised that fingerprints are not entirely foolproof: some toilets flush automatically and the person who uses the toilet may not necessarily be the next person to flush.

Gambhir and his researchers decided to add a small camera which scans the user’s unique “anal print” for identification. “We know it seems weird, but as it turns out, your anal print is unique,” explained Gambhir. The anal scanning is used purely as a recognition system to match users to their data and will not be seen by users or healthcare professionals.

Research on its effectiveness is still in the early stages, with 21 participants having tested the toilet over several months.

The researchers hope that the smart toilet could be a useful tool for individuals with a genetic predisposition to certain conditions, such as irritable bowel syndrome, prostate cancer or kidney failure. Eventually, Gambhir hopes that it may be part of an average home bathroom, with data sent to healthcare professionals for monitoring purposes.

A survey of 300 prospective smart toilet users found that 37 per cent of people were “somewhat comfortable” with the prospect of the toilet, while half felt comfortable with it (and 15 per cent were “very comfortable”). The most commonly reported concerns were over privacy and data security.

“Health data contains among the most sensitive and revealing information about anyone,” Edin Omanovic, advocacy director at Privacy International told the Thomson Reuters Foundation.

“Linking it to someone’s biometric ID risks exposing intimate details to third parties, either through opaque data sharing or security flaws which leave backdoors exposed.”

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