Monday, October 19, 2015

Elderly Monitoring: Telling a Story with minimal sensors

How many sensors do you need to tell a story?

I have a motion sensor in my mother-in-law's room, her bathroom (down the hall from her bedroom)  and an open/close sensor on the house front door (which is next to her room).   With just these two (cheap) X10-RF sensors I can tell a lot about the nightly activity of my dementia suffering guest.

If you  haven't been following this blog's "elder care" stories: My mother-in-law has dementia so she lives with me and my family. She is apt to get confused and wander. Her room (the only available extra room in the house) is unfortunately next to the front door.  The rest of the bedrooms are one floor up. Mother-in-law needs constant monitoring. She has "escaped" our house several times (at night and at dawn -- when we are still asleep) with the idea that she is going to walk to "her house".  She also complains of insomnia and chronic pain.  Is she sleeping at night? Is she up wandering the house?

So, I've designed a cheap  sensor-based monitoring system. I explained that tech setup elsewhere.  Here I want to posit the question: What kind of "story" can you tell with a couple of sensors?

With just a bedroom, bathroom motion sensor and a sensor to alert us when she opens the front door, I can talk about the following:

  • Did she leave the house or is she just "checking the weather" (door opens but is followed by movement in her bedroom)?
  • Is she restless at night (motion in bedroom)?
  • How many times did she visit the bathroom?
  • Is she in the bathroom for an unusually long time? (Bathrooms are where a high incident of heart attacks tend to occur)
  • When did she get up in the morning? (Motion in bedroom, then bathroom, then bedroom again)
Now, my current software doesn't tell a complete story (yet), but with the reports/alerts it generates, my wife and I can determine with a quick view of the data on our smartphone, any of the above scenarios.

I'd like to add a couple more sensors, maybe a light sensor and temperature monitor for the bedroom to help flesh these stories out.

The moral (of this post) is: You can tell a lot with just a few sensors and a lot of common sense.  It isn't about the "hardware tech". It is, ultimately, about making sense of data.  I want to get my software to the point where it "tells the story" rather than just provide data for my wife and I to review.  Here is my ideal morning report (sent to my phone instead of the raw data events):

Betty slept between 9:30pm and 6:15am, awaking at 11:15pm and 2:30am to go to the bathroom.  At 6:30am she opened the front door, closed it and went back into her room. Her room light has been on since 6:45am and there is currently no movement in her room.
I don't need this report in verbose english (like above), but I should be able to quickly derive the above story from summarized data points.  All of this can be surmised by the current three sensors.


  1. Perhaps a simple timeline could tell the 'story' in a visual way? Then you could collect and compare the graphs across different days.

    A visualisation like this perhaps:

  2. That visualization looks interesting. Thanks. It is something to consider once I am able to start producing the summary.