Having an open PCB around as a medical device is rather impractical. Aside from being easily damaged, these devices are expected to come in contact with people who are not professionals used to dealing with electronic components. Having them placed on conductive surfaces, tossed around from time to time and subjected to all manners of "everyday" abuse is expected.
To that end, we designed a very simple, but sturdy 3D printed box to protect the electronics. It is based on a popular open SCAD solution by Kelly Egan, modified to fit a slightly different Arduino clone board, the ECG shield and a port for electrodes.
The board is screwed into the box using 3 screws, and those are the only 3 contact points to the box, other than the cables when plugged in. Lid is snapped on firmly and held by friction. If the box is dropped with enough force (roughly the force of a grown man slamming it into the ground on purpose), the lid may snap off. Using a lever against the four corners of the box will easily snap the lid off step by step.ž
All in all, it is a simple solution to a simple problem.