Could smart toilets one day replace smart watches?

Could smart toilets one day replace smart watches?

Wearable tech is transforming the way we approach monitoring and managing our health, but could smart toilets one day trump their performance?

This is the question a team of metabolic researchers at the Morgridge Institute for Research and University of Wisconsin-Madison asked and answered. Their findings are detailed in a paper entitled 'Real-time health monitoring through urine metabolomics1' which was published in the recent edition of the Nature Digital Medicine journal.

The research concept was born during a group meeting where Joshua Coon, one of the paper's lead researchers, mentioned his interest in urine testing. While the comment was initially met with laughter, Ian Miller, the paper's other head researcher, realised that he liked the idea of tracking urine. Miller already monitored several health-related metrics in his own life.

What makes urine interesting?

Urine samples are a vital part of medical monitoring. In fact, the science of examining urine as part of the medical diagnostic process is as ancient as disease itself2. Archaeological evidence indicates that ancient Egyptian and Babylonian physicians noted their observations gleaned from urinalysis as early as 4000 to 5000 BC3.

Besides being readily available with a distinct appearance that changes under various circumstances, urine provides liquid insights into a variety of physiological events. Everything from a person's nutritional and exercise habits, use of medication, sleep patterns and multiple lifestyle choices can be detected in urine. Furthermore, it contains metabolic insights into what's going on within the body. It can reveal everything from pregnancyto health conditions like urinary tract infection (UTI)5, diabetes, liver6 and kidney disease7 as well as sexually transmitted diseases (STDs) and more. 

Urine Sample

Urine self-monitoring, technology and the research results

With DIY urinalysis as the ultimate goal, researchers went out and bought a couple of coolers, and their urine collection and research began with the aim of answering two critical questions:

  1. Could frequent urine sample testing and monitoring offer valuable, real-time data on a person's health?
  2. Could a technology platform be modified to be used in toilets to make urine collection easy, accurate and cost-effective?

To answer the initial question, they conducted a small pilot study with Coon and Miller collecting their own urine samples over ten days. They also used wearable technology to monitor their heart rates, caloric intake, exercise and sleep patterns and kept records of their food and drink intake. They then tested their collective 110 samples. Gas chromatography and mass spectrometry machines were used to measure and get a readout of their individual metabolic signatures.

What they found was that the urine samples offer unique insights into the minutiae of a person's daily life. In these samples, the researchers could detect the biomarkers connected with their alcohol and coffee consumption and that these correlated with their intake logs. One of the researchers took acetaminophen (paracetamol). This medication caused a spike in ion intensity that was noted in the urinalysis results. The metabolic changes experienced during physical exercise and sleep could also be precisely measured.

Based on these findings, The Coon Research Group is developing a smart toilet that will be equipped with a portable mass spectrometer. The device can recognise the user and process samples to test for multiple factors. Upon completion, the toilet will be installed in the group's research building to expand the number of users. 

The researchers know that laboratory urinalysis can accurately measure urine samples and are sure that their toilet can accurately sample urine. However, the major challenge lies in designing a working prototype that is simple and affordable enough for people to use.

While the pilot experiment didn't explore health question, the potential applications are endless. The researchers believe that this form of testing could help to determine how individuals metabolise certain prescription medications. This can help to detect the potential benefits and risks associated with these medications in the individual in question.

The global population is ageing, and these individuals will soon require higher levels of at-home care. DIY urine tests in the form of smart toilets could help their caregivers to determine whether or not drugs are being administered correctly and are working effectively.

According to Coon, the notion of  'smart toilets' has some major population-wide health implications similar to that of the National Institutes of Health 'All of Us' human genome database6. Coon explains that if the data from thousands of smart toilet users could be correlated, the toilets could begin to provide real diagnostics. These findings may even serve as early warning systems for bacterial or viral outbreaks.

The current analyses are conducted on machines valued at $300,000. However, Coon says that portable mass spec technologies are available at a fraction of the cost. He believes that with the massive market potential for such devices, the toilets could eventually be affordable and accessible to the masses.



1. Miller I, Peters S, Overmyer K, Paulson B, Westphall M, Coon J. Real-time health monitoring through urine metabolomics. NPJ Digit Med. 2019;2(1). doi:1038/s41746-019-0185-y
2. Eknoyan G. Looking at the Urine: The Renaissance of an Unbroken Tradition. American Journal of Kidney Diseases. 2007;49(6):865-872. doi:1053/j.ajkd.2007.04.003
3. History Of Urine Testing - A History Of Urine Tests In The Investigation Of Human Disease. Institute of Biomedical Science; 2005:7-8. Accessed November 14, 2019.
4. Morse J, Calvert S, Jurkowski C, Tassinari M, Sewell C, Myers E. Evidence-based pregnancy testing in clinical trials: Recommendations from a multi-stakeholder development process. PLoS ONE. 2018;13(9):e0202474. doi:1371/journal.pone.0202474
5. Chu C, Lowder J. Diagnosis and treatment of urinary tract infections across age groups. Am J Obstet Gynecol. 2018;219(1):40-51. doi:1016/j.ajog.2017.12.231
6. National Institutes of Health (NIH) — All of Us. November 14, 2019.