Testing

There are two key innovations in the initial MDI concept; an air vortex, which is intended to deliver salbutamol more effectively by creating a convergent stream of air directly through the throat, and a dosage timer, which prevents the user from ineffectively taking multiple doses in quick succession.

Vortex component printed in PLA

Component with fan for testing

Using Solidworks, we quickly modelled up the vortex generating component from the concept and fabricated it using an Ultimaker (a desktop FFF machine, also referred to as FDM) in order to evaluate its effectiveness.

The tolerancing of the component is designed to create an almost airtight seal with the canister- and thereby causing it to act like a piston, so that its return to the default position can be slowed to prevent quick dosing.
To test the vortex properly, another component will need to be added to the top to control the intake of air.

The most interesting variable that was observed from this test rig is the nozzle. In its current state, the nozzle focused the spray of salbutamol with high intensity, which could make it quite unpleasant to use. With some tweaking, the nozzle may be able to slow the velocity of the spray so that it is more comfortable to use.