METERED-DOSE INHALER COUNTER (MDI) WITH LATERAL SWITCHES AND METERED-DOSE INHALER INCLUDING SUCH A COUNTER

摘要

A dose counter for a metered-dose inhaler (MDI) has an actuator housing and canister with an activation valve at a valve end of the canister. The dose counter includes a circuit assembly having a substrate with at least a first and a second switch thereon. The first and second switches are sized and positioned to interact with the valve end of the canister when the canister moves from a rest position to an activation position, such that the first switch is triggered when the canister reaches a first longitudinal position and the second switch is triggered when the canister reaches a second longitudinal position that is offset from the first longitudinal position during movement of the canister from the rest position to the activation position. A counting circuit is configured to receive a signal from the first and second switches and to determine when the metered dose inhaler is activated.