Creating an interactive pill box for people with Alzheimer's

Liberty, Hetty and I began STEM club in September, the beginning of this academic year. The main reason why I joined was because I knew I definitely wanted to do a STEM career in the future, but I wasn't sure what sort of STEM career to do. This was where we were introduced to the "Talent 2030 National Engineering Competition for Girls", which all three of us were interested in doing because the brief - research and present a solution to a 21st century problem - was broad enough to give us room to do the things we wanted.

For the first two weeks, we spent our time brainstorming ideas. One idea was electricity generation, since we are all aware that energy is a very precious resource. Another was recycling and sorting, since this is something that will become increasingly important as natural resources become depleted. Our final idea was to do with healthcare - in particular, pillboxes and helping dementia patients because dementia and Alzheimer's is on the rise. After doing research, we found that half of adults in England take prescription pills regularly, so clearly there is a very large market for this. Liberty in particular wanted to develop an interactive pill box because her grandparents regularly take pills and have difficulty remembering when to take them.

The second stage was the interviews. To get an idea of the market for pillboxes, I interviewed two local care homes and from these, I gained a wealth of information. The main problems that people faced when taking pills was what to take (getting the right pills), when to take it (the timings), how to take (orally, after a meal...), and how much to take (the dosages). One carer highlighted the need for staff to monitor these things for a patient - MARs sheets keep a record of this in care homes. The second one brought to our understanding the importance of a discrete, portable device so that people don't feel embarrassed when taking pills.

From this, we began to create our device. We would use LEDs and sound to remind the patient, and notifications on a mobile device. We wanted an app connected to the pillbox which could give live updates of the status of the pillbox remote monitoring, locks and unlocks the pill pods at the right time, includes a record of pills taken and when, and has a database of all the medical conditions and pills the patient had. Also, we wanted it to include a battery reminder so the patient would know in advance when to change the batteries and some sort of feature that could remind the patient when to order more pills and where they should be placed.

The division of the work was quite simple. Liberty was very interested in mechanical design, so was in charge of making the pillbox (consisting of clear acrylic, with laser cut layers, to allow us to take it apart for repair, and for the judges to view what was inside); Hetty was good at coding, so did the software (using the BBC Microbit, and the touch develop editor); I enjoyed designing circuits, so focused on the electronic hardware for the project.

The project took off quite slowly, as we spent a lot of time focusing our ideas and drawing up detailed plans. However, after a couple of weeks, everyone was clear on what they were doing. The first problem we faced was that the microbit that Hetty was using could only programme 4 outputs, but we needed to be able to control 14 LEDs; I decided to use a 16bit decoder which could take the 4 outputs from the microbit and individually control up to 16 outputs; four outputs presented as a binary number can give up 16 possible combinations which can be decoded into useful individual outputs.

After sketching out my final circuit designs with an integrated circuit, 16bit decoder, a microbit, LEDs and resistors, I began using a breadboard to experiment with the decoder chips, microbit pins and LEDs. Then I used PCB design software to create the circuit layout on copper clad plastic board, which was engraved on a CNC mill. The board was cleaned and drilled ready to solder on the components. One problem I faced was that there were 14 LEDs for each of the 14 days; this meant lots of tracks, so I had to draw very thin tracks. I needed to do some extremely fine soldering, to make sure that the solder did not run over the tracks. The pads for the LEDs needed to be precisely over the holes Liberty had drilled, which required some very precise measuring. Another problem I faced was that the power supply for the decoder that I ordered was minimum 5 volts - but the power supply for the rest of the circuit was 3 volts. I could either use a step up converter, a separate power supply, or order another decoder with a lower supply voltage. I chose the final option because using a step up convertor would complicate the circuit and it may not fit on the PCB, and adding more power supplies would cause issues with the rest of the circuit.

I was very surprised when we were told that we had got into the finals and could present our device at the Big Bang Fair. We spent weeks leading up to the event preparing the display, whilst I was working on the PCB and adding a large button for the display. On the day, we were shocked at the sheer number of people attending, the enthusiasm of the crowd, and all the cool gadgets and great companies that were showcasing their products. I loved the GSK stand (with VR, and a whole host of careers such as researchers and testers.) There was a Bae systems and Military stand, with some great demonstrations and tanks and engineering careers showcased.

For our stand, one man seemed very interested and commented at the possible uses for our pillbox - in particular, how important pillboxes would become in the future. He suggested that we also used vibrations to help the patient feel the correct pillbod to take out. I remember another woman was surprised at the facilities our school provided that gave us the opportunity to create such a device. She also said, "I'm glad to see girls doing this sort of thing. I don't see it very often". We were all surprised at the interest we received in our product and I think it was a great experience presenting our prototype to the public.