Tinkl is a health monitoring system spread out across the city that uses information from lavatory usage to allow individuals to keep tabs on their health on the go, and to allow the city to be apprised of the collective health of the city's population.

Our device integrates color, temperature, and turbidity sensors into an unobtrusive package that can operate in the messy environment of a urinal, sensing key properties of urine and transmitting an analysis of the data to individuals on demand, as well as to city authorities for centralized monitoring of a city's collective health.


Currently, individuals do not have easy access to basic measures of their health such as temperature on the go; at the present moment, cities do not also have an effective means to track with frequency, the collective health of the city's population.

Our project aims to remedy this, by creating a small and cost-effective package that can be unobtrusively distributed around a city's many lavatories, and which can sense a person's health markers from a trip to the lavatory, making it easy for a person to keep tabs on his health anywhere and anytime, and allowing for the city's collective health to be monitored in real time.


Functional requirements

  • Urinal puck is capable of collecting urine and analyzing its color, clarity and temperature
  • Collection mechanism capable of preventing cross-contamination of urine samples across different individuals
  • System is capable of predicting basic health markers like hydration level and basal body temperature from collected data
  • System provides means for individuals to log when they are using a urinal and access health data on demand via a smartphone app
  • System stores anonymized collected data on central server, visible only to city authorities for city-wide health monitoring

Non-functional requirements

  • Urinal puck should be small and waterproofed (up to IP65 rating)
  • Urinal puck should be unobtrusive, preventing user discomfort
  • Urinal puck should last ~2 weeks - 1 month on a battery

Use cases

Our systems are designed to allow people to increase awareness of their health, by enhancing the accessibility of key health markers available in urine. We envision several possible use cases for this system:
  • Similar to Hydralert's concept, our system can enhance workplace safety. In industries necessitating outdoor activity, this can allow workers to be aware of markers such as their body temperature and hydration levels, and adjust their water intake accordingly to ensure that they do not suffer the adverse effects of heat stroke or other heat and hydration-related ailments. Employers will be able to monitor their employees overall hydration and health markers, and respond accordingly to encourage better employee health and safety while on the job.
  • Our system also provides a means for individuals to be more cognizant of their health. In urban areas where our system is ubiquitous, an individual's health information can be easily analyzed, and will be collated and made available in an easily understandable format at the touch of a button.

Technical specs



  • Open-EMR - open source electronic health/medical records-keeping system. Can be connected to a MySQL server that stores collected health data.
  • MySQL - open source database technology that can be used to store collected health data.


  • Data format we have developed, to be used by puck to communicate with Raspberry Pi hub

Competitive analysis

Underworlds - project by MIT's Senseable City Lab

Research project analyzing wastewater and sewage for biomarkers of human health, with the goal of massively collecting data and using ananalytics to allow the health of the city to be monitored, from the scale of a neighborhood to the aggregate health of the entire city.

While this project aims to enable city-wide health monitoring through large-scale, city-wide data collection and analytics just like the Underworlds project, we also aim to provide individuals with the ability to have their health assessed on demand, by providing an interface through which they can log their lavatory usage and access their collected health data.

Toto Intelligence Toilet

A smart toilet designed by Japanese toilet-maker Toto, that features a "sample catcher" capable of obtaining urine samples, and which can track your urine temperature, analyze glucose levels and transmit the information to your computer over WiFi, for closer inspection by yourself or a trained physician.

This project is targeted at high-end personal health analytics (it features expensive analysis techniques such as glucose analysis and limited communication); in contrast, we aim to create a low-cost highly networked array of smart urine analyzers that can be used by individuals over a broad swath of geographic locations at any point in time, and which can allow for aggregate health of large areas to be tracked.

Hospital in a Toilet - Hackaday project

Project to create a compact device that can be embedded in an individual's toilet and which can perform basic urinalysis (particularly analyzing color and specific gravity of urine) to ease monitoring of both general health as well as chronic medical conditions.

Our project essentially scales the "Hospital in a Toilet" idea up, aiming to create a cost-effective distributed network of such "hospitals" across the city to allow individuals the convenience of checking on their health at any geographical location at any time, while also facilitating city-wide health monitoring.


Based on our design requirements, our lavatory health monitoring system has two primary users and end-goals in mind: to help individuals gain easy access to health monitoring city-wide, and to enable monitoring of the city's collective health through distributed urinalysis. System-wide, our architecture will adopt a hub-and-spoke model, with multiple sensing nodes in each bathroom (urinal pucks) connecting to a local bathroom-level server/gateway which performs analysis and interacts with individuals requesting personal health data, and which also funnels data to a central city server.

In order to gather data, the user will urinate into the urinal. The puck will collect this urine passively and will be woken up by the presence of urine. Once woken up, it will begin sensing and data collection and stream its results to the hub located in the bathroom. The hub will aggregate data from multiple pucks and periodically send it to the city-wide server for further processing. A user can also connect to the local hub to gather basic analytics and data after indicating their desire to receive such data.

Information Flow

System Interaction

Our system uses a number of different technologies to facilitate all of the communication between different components. Below we've detailed the methods by which each component will talk to each other component. For simplicity, only one puck and hub are drawn, though the communication technologies between the pucks and hub, as well as those between hubs and central server, trivially scale to multiple connected devices. In short, the puck communicates with all of its various sensors through either an I2C ADC or directly over I2C. The puck transmits its data to the hub over an I2C radio, which then forwards the information to the server via WiFi.

Team members

Vasu Agrawal

Eric Fang

Matthew Lee

Joel Loo

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