Measuring your health while seated on the toilet

Measuring your health while seated on the toilet

Eva Wentink

Principal member of technical staff

In this article, we take a look at the work being carried out by our researchers. This time, we will be discussing our research on “non-obtrusive monitoring of a range of (physiological) health biomarkers while seated on the toilet” by Eva Wentink, Principal Member of Technical Staff at the OnePlanet Research Center. A precursor to the smart bathroom. At last year’s imec Intellectual Property Day, Eva received an IP Award for this research. 


A crazy idea 

“It all started with a crazy idea,” says Eva. “Can we also measure that which we already measure on the chest through our buttocks? Together, we set out to measure the heart rate, blood pressure change, breathing and hydration levels at the Lowlands Music Festival visitors using a toilet seat and toilet bowl.” 


Seated data delivery 

“At imec, we have been carrying out a great deal of work on health patches. While these do yield high-quality data, you are often only measuring for a week (albeit continuously). If you want to move toward long-term monitoring, however, a week is not enough. As such, you really need to be able to measure for six months to a year in order to say something meaningful about trends.” 

Given that everyone visits the bathroom several times a day, it is the ideal place, given that they are already sitting on the toilet seat, to use sensors to measure heart rate, breathing, blood pressure change, temperature of the buttocks, weight, and weight loss.  

Together with her colleague Evelien Hermeling, Principal Member of Technical Staff at the Holst Centre, among others, Eva traveled to Lowlands. There, they also directly shared the results of their measurements with visitors. For example, festival-goers were given teasing advice about what would be best for them to eat and drink at the next-door restaurant at the festival. “If you have an elevated heart rate, together with blood pressure fluctuations, better not eat desert. When your hydration is low – or you have actually drunk too much alcohol – drink water!”  

The Lowlands music festival test turned out to be a great success, generating with it a great deal of publicity. 


Measuring symptoms to prevent something worse 

Meanwhile, the OnePlanet Research Center was also set up, focusing on preventive health care, among other things.  

“The innovation that came with the toilet seat fits right into that,” says Eva. “If people had toilet seats like that at home, they would not have to check anything, yet you would still be able to collect all the data you need. As such, we continued to develop the toilet seat. Today, the smart bathroom is one of OnePlanet’s cooler research programs.” 

Meanwhile, the measuring device became more mature and was tested as part of a “Citizen Science” study, wherein residents of Gelderland who signed up for the project were given the toilet seat for two weeks to try out at home. Armed with this feedback, Eva and her team were able to improve the prototype.  

“We have just launched clinical trials to see how the toilet seat works in practice,” Eva informs us. That research is being done in patients with inflammations of the digestive tract, such as Crohn’s disease. “We will be following these patients from the time they are given medication during a so-called flare-up, and then measure symptoms for an eight-week period. This will hopefully enable us to see when and if the symptoms subside. In the future, we hope to turn that around and alert someone if any inflammation is imminent. People can then take precautions, such as resting or contacting their doctor, thereby ensuring their symptoms do not worsen.” 



A decade ago, Eva started her career at imec. Having completed her studies in biomedical engineering at the University of Twente in 2008, she proceeded to pursue her PhD research there. Her focus was on exploring how individuals after a lower leg amputation could effectively engage their upper-leg muscles to prevent the knee from buckling. “I investigated the possibility of controlling the knee using the remaining muscles.” 

Choosing imec was influenced by the customer-centric approach of the organization. Eva is also drawn to the diversity of projects and the open communication and collaboration between colleagues. “You can always discuss with colleagues about the projects they are working on or invite someone to brainstorm with you.” 

Eva describes herself as highly practical. “For me, it’s like: ‘I have this idea, let’s test it out.'” This practical approach extends to her personal life, where she constantly experiments with her 3D printer and soldering machine, dedicating time to work with electronics. “Currently, I’m enhancing the intelligence of my home, like smart lamps and heating to conserve energy. I always look at what can be improved.” 

Apart from the toilet seat, Eva and her team are exploring alternative methods for early detection. “Currently, we are examining urine-based parameters to assess hydration levels, for instance. When combined with the toilet seat, this can provide a comprehensive overview for early detection.”