‘Smart toilet’ monitors for signs of disease
There’s a new disease-detecting technology in the lab of Sanjiv “Sam” Gambhir, MD PhD, and its No. 1 source of data is number one. And number two.
It’s a smart toilet. But not the kind that lifts its own lid in preparation for use; this toilet is fitted with technology that can detect a range of disease markers in stool and urine, including those of some cancers, such as colorectal or urologic cancers. The device could be particularly appealing to individuals who are genetically predisposed to certain conditions, such as irritable bowel syndrome, prostate cancer or kidney failure, and want to keep on top of their health.
“Our concept dates back well over 15 years,” said Gambhir, professor and chair of radiology. “When I’d bring it up, people would sort of laugh because it seemed like an interesting idea, but also a bit odd.” With a pilot study of 21 participants now completed, Gambhir and his team have made their vision of a precision health-focused smart toilet seat a reality.
Gambhir’s toilet is an ordinary toilet outfitted with gadgets inside the bowl. These tools, a suite of different technologies, use motion sensing to deploy a mixture of tests that assess the health of any deposits. Urine samples undergo physical and molecular analysis; stool assessment is based on physical characteristics.
The toilet automatically sends data extracted from any sample to a secure, cloud-based system for safekeeping. In the future, Gambhir said, the system could be integrated into any health care provider’s record-keeping system for quick and easy access.
A paper describing the research was published April 6 in Nature Biomedical Engineering. Gambhir is the senior author. Seung-min Park, PhD, senior research scientist; David Won, MD, PhD, former visiting scholar in the Molecular Imaging Program at Stanford; and postdoctoral scholar Brian Lee, PhD, share lead authorship.
Pulling double duty
The toilet falls into a category of technology known as continuous health monitoring, which encompasses wearables like smart watches. “The thing about a smart toilet, though, is that unlike wearables, you can’t take it off,” Gambhir said. “Everyone uses the bathroom — there’s really no avoiding it — and that enhances its value as a disease-detecting device.”
Although the idea may take some getting used to, Gambhir, who holds the Virginia and D.K. Ludwig Professorship for Clinical Investigation in Cancer Research, envisions the instant heat smart toilet as part of the average home bathroom. In facilitating that broad adaption, Gambhir designed the “smart” aspect as an add-on — a piece of technology that’s readily integrated into any old porcelain bowl. “It’s sort of like buying a bidet add-on that can be mounted right into your existing toilet,” he said. “And like a bidet, it has little extensions that carry out different purposes.”
These extensions sport an array of health-monitoring technologies that look for signs of disease. Both urine and stool samples are captured on video and are then processed by a set of algorithms that can distinguish normal “urodynamics” (flow rate, stream time and total volume, among other parameters) and stool consistencies from those that are unhealthy.
Alongside physical stream analysis, the toilet also deploys uranalysis strips, or “dipstick tests,” to measure certain molecular features. White blood cell count, consistent blood contamination, certain levels of proteins and more can point to a spectrum of diseases, from infection to bladder cancer to kidney failure. In its current stage of development, Gambhir said, the toilet can measure 10 different biomarkers.
It’s still early days, though, with a total of 21 participants having tested the toilet over the course of several months. To get a better feel for “user acceptance” more broadly, the team surveyed 300 prospective smart-toilet users. About 37% said they were “somewhat comfortable” with the idea, and 15% said they were “very comfortable” with the idea of baring it all in the name of precision health.
One of the most important aspects of the tankless smart toilet may well be one of the most surprising — and perhaps unnerving: It has a built-in identification system. “The whole point is to provide precise, individualized health feedback, so we needed to make sure the toilet could discern between users,” Gambhir said. “To do so, we made a flush lever that reads fingerprints.” The team realized, however, that fingerprints aren’t quite foolproof. What if one person uses the toilet, but someone else flushes it? Or what if the toilet is of the auto-flush variety?