Engineering meets medicine: A toilet to monitor our health or ill-health.

Currently, the toilet can test for up to ten different biomarkers from analyses of stool and urine samples, according to a Stanford press release. (Nature Biomedical Engineering)

This blog was written by Mairéad Lyons. Mairéad is a Senior Consultant to YouScreen the HPV Self-Sampling study.  She has been working in healthcare for over 30 years, first as a nurse, then in health promotion before moving into public policy research and service improvement.  The last ten years she has worked to improve patient outcomes through earlier diagnosis and standardisation of cancer service provision in Ireland and England.

When I read about a study testing a toilet system that could monitor our health through tracking our pee and poo (urine and stool), I honestly thought this is science gone mad.  However, the reality of how technology and engineering are helping medicine achieve breakthroughs today is no longer the preserve of sci-fi movies.  Using fast speed camera technology, infrared sensors, fingerprint, analprint and flushable testing strips, a new fandangle toilet is proving to be valuable to our health.

We have smart TVs, smartphones, smart computers and smart homes why not a smart toilet.  Furthermore, with governments now giving serious consideration to using technology for population health surveillance to track individuals with COVID symptoms and/or those who are immune to it, the future of health monitoring has radically changed.

Just how close are we to installing one of these toilets in our homes? Is it a step too far to have a camera looking at our bums?

The mountable toilet system

Research on a mountable toilet system by a large group of engineers, scientists and clinicians from USA, Korea, Canada and the Netherlands, has been published this month. At first, I was amazed that so much effort had gone into this, yet strangely it makes sense.

Many of us have our health monitored through clinic health checks, providing a sample of urine, stool or blood for analysis. Other health monitoring gadgets or devices are wearables such as 24hour heart monitoring devices, Fitbit’s or smartwatches.  A seated toilet is in every home in the developed world.  We use a toilet regularly and do not have to be reminded to do so.  It has the potential for continuous health monitoring like nothing else in the home.  This ‘smart’ toilet could potentially find early signs of disease including some cancers such as bowel or prostate cancers.

Using available disease biomarker information on testing urine and stool, the researchers developed a way to continuously monitor changes in excretions using the toilet.    The toilet has been tested on a small number of participants (21 – all male) in order to develop the technology.  Testing urine can help identify diseases such as diabetes, liver diseases, some cancers, bile system blockages and other diseases.  Reviewing and testing stool can tell us more about diseases of the gut and intestines including poor nutrient absorption, pancreatitis, infections, irritable bowel syndrome and cancers.

The gadget can be added to a regular seated toilet and readily integrated into the toilet bowl.  One strip for urine to test for 10 different biomarkers was developed.  The strip is produced automatically from a cartridge of loaded strips when a sensor detects that urine is flowing into the toilet.  The strip sticks out into the toilet bowl as urine is sprayed onto it. The information is gathered in real-time by a video camera in the bowl and analysed by a computer comparing it to a healthy control sample.  They built tiny high-speed cameras located in the bowl and trained a computer to recognise and measure the flow of urine, time urinating and total volume.  The strip is environmentally friendly, and once retracted for analysis is discarded into the toilet bowl.  The cartridge readies a new strip for the next visit.

Stool monitoring was a little trickier.  The researchers needed to train a computer to recognise the type of stool being deposited into the toilet.  It needed to be able to distinguish it by shape, size and consistency according to a standard international scale called the Bristol stool form scale (BSFS).   They then developed a sensor to measure the force pressure of someone sitting on the toilet bowl.  It sends a message to the computer confirming the presence of a user.  It sends a signal to the video camera to record the toilet event; it can tell the length of each seating time.  The bowl has an LED strip that ensures the standard of lighting for the video cameras to be effective for each urine and stool event.   Images are taken which differentiate the clean, urine, stool or toilet paper state.  The duration between each stool drop and the last stool drop can be calculated. The toilet has the ability to monitor changes over time.

Data privacy and acceptability

Now how does the smart toilet know who you are?  The flush lever has a fingerprint scanner that detects who is using the toilet.  They have been able to show that our bums have a special contour print just like our fingerprint called analprint.   The camera in the toilet bowl takes a picture of your bum to confirm it really is you using the toilet.

The good news is that information being sent from the urine strip, images and scans of the toilet event are encrypted (made difficult to identify to a person) and delivered to a secure data portal in the cloud.  Here the information is kept private.  If this smart toilet was to become a reality and produced at scale, managing people’s health information including pictures of the stool, urine and bums would need tight security control.

In order to make full use of this technology, the data collected would need to be accessible by health providers who could interpret and act on it when necessary. This presents an ethical and data protection dilemma. Health providers are increasingly giving patients access to their Electronic Health Record.  This technology could work well with this type of feature.  Perhaps the safest way to ensure data privacy is to keep the data locally (i.e. in the individual’s device/cloud, under their control).  However for such technology to have substantial benefits to the user the data must be stored in a central repository where it can be analysed, patterns identified and alerts provided to the user to suggest a visit to their doctor.

The researchers went further and surveyed 300 people in Stanford University about their attitudes to a smart toilet that uses video images.  Only 35% were comfortable with a camera in the toilet bowl that takes pictures of their stool and bum.  75% were comfortable with a camera that only took pictures of the stool and not of the bum.  Though this is a highly educated survey population, it indicates there is still some way to go before the general public could be willing to have health monitoring by their toilet bowl.

This research was more about the possibility, taking the available clinical measures and working out a way to capture them in our urine and stool.  It can be done, they have shown this. However, with such a small study population of 21 men and results not yet accurate enough for reliable action, this toilet is still in prototype development.   Whether continuous monitoring technology improves disease detection and early intervention can only be concluded following a clinical trial.

What is next

The study team mention incorporating the gFOBT test (detects blood in stool and is used in bowel cancer screening) in future. This is a development worth following given that uptake of bowel cancer screening is low and most people cite having to handle stool as a limiting factor for participation. Unfortunately, complex biochemical analyses (like those needed for HPV testing or methylation) are not likely to be achievable in a toilet system.  Perhaps we will have to settle for the toilet collecting samples in a simple and hygienic manner and rely on our willpower to post or deliver the samples to our health providers. The study team are committed to taking this invention further; who knows what the future holds. Perhaps in selected populations, this smart toilet could help prevent cancer through continuous health monitoring.  Perhaps it is just too whacky.  It is likely to be expensive.

Further reading:

‘Smart Toilet’ With AI Automatically Scans Stool for Blood and Consistency


The views expressed are those of the author. Posting of the blog does not signify that the Cancer Prevention Group endorse those views or opinions.

Subscribe to our mailing list

1 Comment

  1. I am the leading author of the manuscript – We have 21 participants for the study – some of them are female. Only male participants were recruited for the uroflowmetry module. For the defacation monitoring – we had 6 male and 5 female participants.

Leave a Reply

Your email address will not be published.