How an in-toilet biosensor works
An in-toilet biosensor analyses urine inside the toilet during normal use, without strips, cups or any action from the user. In the ablute_ (Ablute) toilet, the sensor is a bioFET: an electronic sensor that converts the presence of a specific molecule — creatinine, for example — into an electrical signal.
What is a bioFET?
A bioFET (biologically sensitive field-effect transistor) is a transistor whose sensing surface is prepared to recognise one specific molecule. When that molecule binds to the surface, it changes the electrical current that flows through the transistor. Measuring that change tells how much of the molecule is present.
bioFETs read molecules directly as an electrical signal, without coloured reagents or optical readers. They can be made very small and integrated with electronics, which is what makes it possible to place them inside a toilet.
What ablute_ detects
The ablute_ bioFET has been demonstrated detecting creatinine. Creatinine is a waste product of normal muscle metabolism that the kidneys remove into urine; in urine analysis it is commonly used as a reference for how concentrated the sample is.
Further markers are under development and will only be listed once they are validated.
From the toilet to the user
The sensing module sits inside the ablute_ toilet and analyses the sample during normal use. Readings are processed by the device and shown to the user as trends over time, so that the focus is on changes rather than on a single value.
How it differs from test strips and laboratory tests
Disposable test strips require collecting a sample and reading a colour by eye or with a phone; they give a single, occasional result. A laboratory test is precise but happens rarely and requires a visit.
An in-toilet biosensor is automatic and repeated every day, which makes it suited to following trends. It is not a replacement for laboratory tests or for a doctor's assessment.
Development status
ablute_ is in the pilot phase: the core bioFET technology is demonstrated and working. ablute_ is not yet a certified medical device and does not provide a diagnosis.