Pain is a good thing. It tell us to pull our hand away from the stove and to stay off a turned ankle. But we all have different experiences of pain, and chronic pain degrades our quality of life. A person’s reports of pain will vary from one day to the next based on many factors, so the 1-10 scale isn’t universally effective in determining a person’s pain level. [Scott]’s entry into The Hackaday Prize is based on the classic cold pressor testing device, which measures changes in heart rate and blood pressure in a patient while their hand is immersed in ice water for one minute.

[Scott] has tentatively dubbed his device The Pain Machine, but it does more than the typical cold pressor apparatus; it also delivers simulated pain relief in the form of warm water when the valves are reversed. In addition, the subject under testing can push a button when they’ve had enough. While his original plan used external sources of hot and cold water, [Scott] pulled a couple of Peltier coolers from some wine chillers for a more contained design.

The Pain Machine uses an Arduino ATMega 2560 to control gravity flow solenoids, collect temperature data, and send the data cloudward. A couple of 110V pumps circulate the water. [Scott] will open up the code once he has finished commenting it and fleshed it out with use cases. For now, you can check out his two-minute entry video after the break.

This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.