After about two and a half weeks of system design and component selections, it was very fun to finally see this second generation come together over the last four days. I started with writing the microcontroller prototype code. Then tested that code with the benchtop prototype and made corrections as needed. Once I was confident in the code, it took only a couple of hours to decide how to arrange the electronic components in the enclosure and put everything together. 

I intend to cover the details of the operating procedure and how the device works in later project logs, but I think it makes sense to provide a high level overview here. The second generation OpenFluidWarmer uses a commercially available sous vide cooker to warm and maintain the temperature of a water bath. While the IV fluid is being administered, the operator immerses a length of IV tubing in the water bath. Heat from the water bath will warm the IV fluid as it flows through the length of IV tubing that is immersed in the water bath. The custom electronics assembly can be thought of as a "safety companion" for the sous vide cooker. It includes safety protections like redundant temperature monitoring, a sous vide cooker power disconnect, and fault detection and alerts.

The next step is to develop and perform several tests to ensure that the device operates as intended.