the above described drawing figures illustrate aspects of the invention in at least one of its exemplary embodiments , which are further defined in detail in the following description . referring initially to fig1 to 4 inclusive , of the drawings , the actuator device in the first embodiment will be described . the actuator device in the first embodiment is indicated generally by reference numeral 100 . an inhaler i , comprising a housing and a pressurised canister , can be engaged with the actuator device 100 . the actuator device 100 includes a lip sensor 105 is provided on the mouthpiece 101 , mouthpiece protector cover 102 , counter viewing window 106 , the external interface 110 and the battery access cover 112 . the lever mechanism is indicated generally by reference numeral 115 . the manner of operation of the actuator in the first embodiment will now be described . the voltage supply at start delivery 5 f and 5 g causes a lever pivoted at 5 h to compress the return spring 5 i to engage the arm attached at 5 k to slide through 5 j until the arm attached 5 e is pulled past lock 5 d . the return spring 5 c will engage the lock 5 d behind 5 e and hold the arm that engages 5 l pivoting arm which pushes down 5 m base plate . at the time cessation control point as determined by the timer is reached , a voltage is applied to 5 a and 5 b which contracts the actuator at 5 c to release the fixed point 5 e and the arm is returned by the return spring 5 i . the lock 5 d is returned by the spring 5 c . case fixed points are 4 a , 5 b , 5 f , 5 h , 5 . referring now to fig5 to 13 inclusive , the actuator device in the second embodiment will now be described . the actuator housing in the second embodiment is indicated generally by reference numeral 200 . in fig5 to 10 , the actuator device 200 is shown ready for use , with an inhaler i ( comprising an inhaler housing and a pressurised canister ) engaged in the actuator device 200 . referring to fig5 to 13d , the actuator 200 includes the following features : air vents 201 , plastic housing 205 , led light 206 , pmdi inhaler i , seal 208 , rear hand grip 207 and battery charging points 209 . referring now to fig1 a and fig1 b , the sectional view in fig1 a and exploded sectional view of lever linkage in fig1 b , the general reference numeral for the mechanism is 220 ; and the mechanism 220 includes an electrically driven linear motor 221 ( e . g . servo , gearbox or solenoid ), linkage 222 , plastic cam 223 ; and lever arms 224 . a pmdi canister inhaler a including canister c , lever fixing pins 226 , lithium ion battery 227 , pcb board 228 and gears 229 . the lithium ion battery 227 lasts up to 1 year . the lithium ion battery 227 may be rechargeable . if it is a rechargeable battery , then the two recharging contact points 209 enable power to flow into the battery when placed in a re - charging unit ( not shown in the drawings ). furthermore , in the second embodiment , the actuator device is in the form of a housing into which an inhaler is inserted and at least partially housed such that the mouthpiece of the inhaler is accessible to the patient for insertion of the inhaler mouthpiece in the patient &# 39 ; s mouth for drug delivery . the actuator device housing is adapted such that the inhaler is removeably inserted in the housing provided by the actuator device in a clip - in manner . furthermore , the actuator device housing is adapted such that the inhaler is removable from the housing in an easily operated clip - out involving the user holding a lower portion of the inhaler or underneath the mouthpiece of the inhaler and only a relatively small force is needed to disengage the inhaler from the housing so that the inhaler is removed in a “ clip - out ” manner . fig1 a and 10b are section views showing the internal electrical servo gearbox 221 , linkage bar 222 , lever arms 224 , plastic cam 223 , pmdi canister c , sensor 225 , lever pivoted pins 226 , servo or gearbox fixing points 226 . referring to fig5 to 10 , the operation of the device will now be described . in use , an inhaler i is clipped into the housing defined by the actuator device 200 and the mouthpiece of the inhaler will be exposed as shown in fig1 a . the user positions his / her mouth over the inhaler mouthpiece and inhales . because of this inhalation , air is drawn in through the air vents 201 and this air flow activates the breath flow sensor 225 . the activation of breath flow sensor 225 or vane sensor , in turn , causes activation of an electrically driven gearbox servo or gearbox 221 which pushes the linkage bar 222 and thereby pushes the lever arms 224 so as to compress the pmdi inhaler canister c to release drug so as to deliver the drug dosage in the optimum way . thus the breath flow sensor 225 is operable to activate the electrically driven gearbox servo or gearbox 221 at about one quarter of the way through an inhalation by a person who is using the actuator device 200 . thus , the person using the actuator device 200 including the breath flow sensor 225 places the mouth piece of the actuator device 200 to his / her mouth and inhales . at about one quarter of the way through that inhalation , the breath flow sensor 225 detects the breath flowing past the sensor 225 and activates the electrically driven gearbox servo or gearbox 221 which pushes the linkage bar 222 and thereby pushes the lever arms 224 so as to compress the pmdi inhaler canister c to release drug so as to deliver the drug dosage in the optimum way . in this way , as the person inhales , the medicine is released and is taken down into the lungs in a most effective manner i . e . the precisely prescribed amount of medication is delivered to the person &# 39 ; s lungs because the device has been activated during the inhalation . the inhalation of air into the lungs carries the medicine down with the breath directly to the intended point of delivery i . e . the lungs . referring now to fig1 a to 13d inclusive , an insertable adjusting arm for adjusting the available height within the housing defined by the actuator device 200 so as to accommodate differently sized pmdi inhalers , is shown and is indicated generally by reference numeral 250 . rear push in slide button to adjust height 251 , side stabiliser sliding peg 252 , button ejecting spring 253 , base plate with grips to hold a pmdi inhaler 254 , rear locating teeth 255 ; and rear locating locking points for height adjustment of a pmdi inhaler 256 . features and advantages of the actuator device 220 include the following : a portable , battery operated , breath activated pmdi inhaler clip - in attachment is provided by the present invention , for ease of use for patients with reduced or limited dexterity and co - ordination ; electrically driven breath activated clip - in attachment for a pmdi inhaler ; clip - in insertion of the inhaler in the actuator device in the second embodiment and clip - out withdrawal of the inhaler from the actuator device housing in the second embodiment of the actuator device of the present invention ; and clip - on attachment of the actuator device in the first embodiment whereby the actuator device in the first embodiment is engaged with the mouth piece of the inhaler ; and the actuator device in any embodiment of the present invention can engage with most pmdi thereby providing simpler and easier activation and use of any pmdi . to summarize , regarding the exemplary embodiments of the present invention as shown and described herein , it will be appreciated that improved actuator devices for pressurised metered dose inhalers are disclosed . because the principles of the invention may be practiced in a number of configurations beyond those shown and described , it is to be understood that the invention is not in any way limited by the exemplary embodiments , but is generally directed to improved actuator devices for pressurised metered dose inhalers and is able to take numerous forms to do so without departing from the spirit and scope of the invention . it will also be appreciated by those skilled in the art that the present invention is not limited to the particular geometries and materials of construction disclosed , but may instead entail other functionally comparable structures or materials , now known or later developed , without departing from the spirit and scope of the invention . furthermore , the various features of each of the above - described embodiments may be combined in any logical manner and are intended to be included within the scope of the present invention . while aspects of the invention have been described with reference to at least one exemplary embodiment , it is to be clearly understood by those skilled in the art that the invention is not limited thereto . rather , the scope of the invention is to be interpreted only in conjunction with the appended claims and it is made clear , here , that the inventor ( s ) believe that the claimed subject matter is the invention .