You don’t drink? You die!
Dehydration (the lack of water within the body) is a serious threat. You may feel thirsty if your body wants to get hydrated, but your grandma probably doesn’t. As the feeling of thirst decreases with age, the need of water intake rises, due to reduced kidney functionality and more medication which needs to get washed out of the body. High demand of water with low liquid intake = problem. In in 2015, in Germany alone 100.764 people, mostly older than 70, got hospitalized with the primary diagnosis “acute dehydration”, leading to direct costs of more than 275 mio. € for the health system. Not speaking of the > 5000 deaths, and all the suffering and costs related to the possible implications of dehydration: paradox diarrhea, fall, cardiovascular diseases, kidney malfunction.
Why doesn’t anybody do something against dehydration?
Well, people do. Risk patients are monitored with a so-called hydration protocols, a table where the nurse notes down the volume of drinks given to the person of concern, a daily sum is calculated and – if too little was drunk – alarms are raised.
Solving the problem by automation
If in the current state of care liquid intake is not monitored because of the additional time needed for this task, then there is the need to automate fluid intake monitoring.
In other words: we want to minimize the time of human interaction needed for this task. Today, human interaction is needed in two major categories of liquid intake monitoring:
- Measurement of volume: the caregiver estimates/measures the content of a cup and note it down on a piece of paper.
- Evaluation and documentation: end of the day, the caregiver manually sums up all registered volumes, decides if hydration is sufficient and files the table which was used for documentation.
-> We need a sensor device, that automatically measures the drunk volume. To reduce errors (e.g. spilling), it would be best to do so as close to the process of drinking as possible.
-> The measured data should be analyzed and processed automatically. The human should only be needed to act if the hydration level is low.
With these two points and the requirements in mind, the following architecture seems legit:
- Compact: The sensor device is small enough to be added to everyday drinking equipment
- Usable: everybody’s grandma should be able to use the device.
- Affordable: no expensive medTech product. Affordable for everyone!
- Modular: the device is not be limited to only one cup or bottle. It is possible to use it with the different containers we use when drinking every day.
- Robust: the device must withstand regular conditions in a nursing home. All parts in contact to liquid can survive the dishwasher.
- Exact: The accuracy of measurement is comparable to today’s practice
- Low power: A small coin cell can power the device for weeks.
Note: This project is a private follow-up of research which was done by J. Kreutzer, J. Deist and myself at the Institute of Micro Technology and Medical Device Technology (MIMED) at the Technical University of Munich. Results of the research were published here. HydrObserve as private project is fully permitted by Prof. T. Lüth, the chairholder.
All progress will be documented intensively in the build logs. Only major advances are added here in brief comments.
- Found the perfect sensor for this application: a tiny magnetic turbine + hall sensor (log 1).
- Used materials of Chinese sensor pass basic food safety test (log 2).