Below is a collection of some of the sources we found for inspiration:
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| Cooking timer |
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| Another cooking timer |
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| Clockwork mechanism |
Cooking Timers contain a (comparatively) simple clockwork mechanism, which causes rotation at a specific rate. This could theoretically be applied to the MDI design to prevent the user from dosing too quickly, although it is exceedingly complex, bulky, and possibly too fragile for any practical inclusion.
Another means of reminding the user to hold their breath could be a limitation on how often the inhaler resets itself before being able to be used again. One way of achieving this could be through the use of a viscous substance, such as grease or glycerine, in a hinge. This would create resistance when trying to reset the inhaler, making it take longer than expected.
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| Glycerine |
Of course, this solution also has its own obstacles such as maintenance, contamination, added complexity, etc. An air piston, like the ones used in some cassette players to artificially slow the opening of the door, would be a better solution, but is still a little too complex.
Ultimately, we selected yet another method for timing doses, which we'll reveal soon...
