'Smart toilet' looks for signs of disease

By Dr. Liji Thomas, MDApr 6 2020

A Stanford study published in the journal Nature Biomedical Engineering in April 2020 reports the development of a new kind of toilet that can pick up signs of an extensive range of diseases, from molecules in stool and urine. This could be extremely useful in repeatedly and inexpensively screening high-risk groups for certain conditions, including those for which a genetic tendency is possible – such as prostate cancer or certain kinds of kidney cancer.

The toilet concept was developed in the laboratory of Sanjiv Gambhir, over 15 years ago. Gambhir is a radiologist and cancer researcher. Though it has raised many a chuckle over the years, his team has now brought the idea to light, making it a prototype of gadgets focused on precision health.

The device

The toilet is just an ordinary one at heart. It has a bowl, a lid, and a flush cistern. On the other hand, it also has motion sensors, molecular probes, and other technologies that trigger an analysis of different health conditions. Whatever deposits occur in the bowl, including urine samples, are subjected to a physical and molecular examination.

The gadgets fitted to the bowl detect the extracted data and send it to a cloud-based secure storage system. This means it could potentially be used to store the information for future reference in any electronic health records system so that it can be retrieved rapidly and conveniently.

The smart toilet automatically sends data extracted from any sample to a secure, cloud-based system for safekeeping. Image Credit: James Strommer

Continuous health monitoring

The toilet is part of a class of devices called continuous health monitoring, which includes gadgets like 'smart watches' that count your steps and your pulse rate. However, unlike a wearable health monitor, says Gambhir, "The thing about a smart toilet, though, 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."

Plug-and-play design

The researchers think the device could and should be made part of the typical home bathroom. In order to roll out a ready-to-use line of smart disease-detecting toilets, they made the sensor addition a separate add-on. This ensures that it can be sold and used ready to mount on any existing porcelain bowl to start operating then and there. In Gambhir's words, "It's sort of like buying a bidet add-on that can be mounted right into your existing toilet." The magic is in the extensions that are designed for different purposes.

Such extensions include a set of monitoring technologies that capture videos of urine and stool passage and samples of the substance passed. These videos are the basis on which the urine is analyzed for its flow rate, the stream time, and total volume, and similar characteristics. The stool video, on the other hand, is processed for its consistency to begin with.

Once these physical parameters have been examined, the toilet uses chemical sensors in the form of dipsticks to detect specific molecules. These include the white cell count, the persistent presence of blood, and the above-normal presence of proteins, as well as of other abnormal substances in the urine. This panoply of tests, while being easy and swift, could raise red flags for a number of medical conditions, ranging from infection to bladder cancer, or even kidney failure. All these potentially life-threatening conditions could, ironically enough, be screened for by simple tests, with this technology.

At present, the toilet can pick up abnormalities in 10 different biomarkers, which are molecules that indicate the presence of a disease condition. Already, the researchers have tested out the concept on 21 people over a few months. They also asked 300 people how they would feel using this kind of disease-screening toilet. In total, a little over half of them said they would be somewhat or very comfortable with using such an intimate device to monitor their health.

User identification

Among all the many facets of this system, it has a built-in user identification system – which may be difficult for some people to digest. The rationale is simple – the device must provide a readout on each person's health separately, making it essential to distinguish each user. The first attempt to integrate this type of user identification system was via a flush lever that uses fingerprints. The limitations soon became apparent – the person who flushed the toilet wasn't always the person who used it. Secondly, if the toilet was of the auto-flush type, it couldn't identify the user.

The second attempt was via an inbuilt scanner to take pictures of this private part of the anatomy – anal recognition technology, so to say. The camera will scan this area to identify the user, because, it seems, the anus is unique from person to person.

However, the researchers stress, the images are locked away even from the user. Neither the individual nor the doctor even sees the images, which are taken purely as a means to recognize the user and link the readout to the correct user.

Useful, secure, totally private screening tool

Gambhir emphasizes that this toilet will never take the place of a doctor, nor will it be able to deliver a diagnosis. In fact, the user will not ever see the data picked up in many cases. Data privacy and secure cloud storage are both essential and advanced parts of this project. The team envisages the ideal situation as being one in which the presence of an abnormality will be sent to the healthcare team responsible for that patient, via an app that is designed to handle such data securely and privately.

Gambhir adds, "We have taken rigorous steps to ensure that all the information is de-identified when it's sent to the cloud and that the information -- when sent to health care providers -- is protected under HIPAA." The Health Insurance Portability and Accountability Act (HIPAA) takes care of patient privacy, placing limitations on the conditions under which healthcare information may be shared.

Reiterating for efficiency

The team continues to work on the smart toilet, focusing on broader participation, developing a greater range of tests to include chemical molecular stool analysis, and enhancing the working of the technologies already in place.

They are also looking into how to offer the user greater customizability, such as glucose monitoring for a diabetic user, or blood detection for an individual at risk for bladder or kidney cancer. Stool analysis for various metabolites could also help enormously to detect certain conditions in their early stage.

Perfect way to screen

Gambhir sums up his vision: "The smart toilet is the perfect way to harness a source of data that are typically ignored -- and the user doesn't have to do anything differently." Perhaps it's time to shed our qualms and embrace the radical concept of a toilet that screens us for disease while we take care of essential functions.