conventional breath activated devices this increased sensitivity is achieved by using the gated channel 133 in fig1 and 2 that opens only after activation this arrangement allows all airflow to pass over the air flow sensor when in the cocked position and will provide activation with a flow rate as low as 2 liters minute this capability for low flow rate activation can be critical for a patient with minimal inspiratory flow during an asthma attack to prevent the loud click on activation that is heard in the use of some breath activated devices the invention may also include a dashpot 137 to dampen the initial motion of the mouthpiece 107 relative to the main body 112 the dashpot thus serves as a sound dampening device to deaden the sound and reduces noise made during activation this device can be manually activated in an emergency in the unlikely case the batteries on the canister runs out of power or there is an electronic malfunction a cover not illustrated over the canister is easily removable to allow manual actuation but a tear sensitive tape will alert the health professional that the device has been tampered with this along with the timer delay described above also discourages the practice known as dumping where the patient repeatedly and rapidly discharges the mdi usually just prior to an appointment in an attempt to hide his or her failure to follow the prescribed medication schedule as described above the device is easy to use requiring minimal hand strength.