If you’re dealing with a chronic illness, the ability to continuously monitor your symptoms is indispensable, helping you gain valuable insights into what makes your body tick – or, rather, mis-tick. However, for many illnesses, you need specialized equipment to monitor them, and it tends to be that you can only visit your doctor every so often. Thankfully, we hackers can figure out ways to monitor our conditions on our own. With a condition called BPH (Benign Prostate Hyperplasia), one of the ways to monitor it is taking measurements of urinary flow rate. Being able to take these measurements at home provides better insights, and, having found flow rate measurement devices to be prohibitively expensive to even rent, [Jerry Smith] set out to build his own.
This build is truly designed to be reproducible for anyone who needs such a device. Jerry has intricately documented the project and its inner workings – the 31-page document contains full build instructions, BOM for ordering, PCB description and pinout diagrams, calibration and validation instructions, and even software flowcharts; the GitHub repo has everything else you might need. We’re pleasantly surprised – this amount of documentation isn’t typically seen in hacker projects, and is even more valuable considering that this is a medical device that other hackers in need will want to reproduce.
For the hardware, [Jerry] took a small digital scale of a certain model and reused its load cell-based weighing mechanism using an HX711 amplifier, replacing the screen and adding an extra box for control electronics. With an Arduino MKR1010 as brains of the operation, the hardware’s there to log flow data, initially recorded onto the SD card, with WiFi connectivity to transfer the data to a computer for plotting; a DS3234 RTC breakout helps keep track of the time, and a custom PCB ties all of these together. All of these things are easy to put together, in no small part due to the extensive instructions provided.