Dry powder inhaler

Abstract

A drug powder inhaler has a cover plate pivotably attached to a lid on an inhaler housing. A lever is pivotably attached to the cover plate. A blister pack disk is rotatably mounted on the housing under the cover plate. A powder duct in the housing extends from a staging chamber underneath one end of the lever to an aerosolizing chamber. An actuator in the housing is pressed to shear open a blister on the blister pack disk and thereby deliver the drug dose contents of the blister into the staging chamber. A switch senses pressure in the mouthpiece and switches on a motor spinning an impeller within the aerosolizing chamber, when inhalation is detected.

We claim:  
     
         1 . An inhaler comprising: 
 a housing;    a staging chamber in the housing, with the staging chamber having an open top, to allow a dose of a dry powder pharmaceutical to move via gravity into the staging chamber from a dose carrier above the staging chamber, and with the staging chamber having a substantially closed bottom end to allow the staging chamber to temporarily hold the dose of dry powder;    a mixing chamber in the housing spaced apart from the staging chamber; and    an enclosed continuous duct extending from the staging chamber to the mixing chamber.    
     
     
         2 . The inhaler of  claim 1  further comprising an inlet extending into the housing to the staging chamber.  
     
     
         3 . The inhaler of  claim 1  further comprising a barrier between the staging chamber and the inlet.  
     
     
         4 . The inhaler of  claim 1  further comprising means for opening the dose carrier aligned above the staging chamber.  
     
     
         5 . The inhaler of  claim 1  wherein the enclosed duct extends substantially horizontally in the housing.  
     
     
         6 . The inhaler of  claim 1  wherein the duct and the mixing chamber have round cross sections, and the diameter of mixing chamber is greater than the diameter of the duct.  
     
     
         7 . An inhaler comprising: 
 a housing;    an air flow path extending through the housing and comprising: 
 an inlet extending into the housing;  
 a staging chamber within the housing with the inlet joining into the staging chamber;  
 a mixing chamber within the housing;  
 a duct in the housing having a first end connecting into the staging chamber and having a second end connecting into the mixing chamber.  
   
     
     
         8 . The inhaler of  claim 7  further comprising a mouthpiece forming a wall of the mixing chamber.  
     
     
         9 . The inhaler of  claim 7  with the mixing chamber having a circumferential wall between flat first and second walls, and wherein the duct connects into the mixing chamber through the first flat wall.  
     
     
         10 . The inhaler of  claim 7  wherein the staging chamber has an open top for receiving a dose of power via gravity.  
     
     
         11 . The inhaler of  claim 9  wherein the circumferential wall has a diameter greater than the diameter of the duct.  
     
     
         12 . The inhaler of  claim 7  wherein the staging chamber has a closed off bottom surface and an open top end.  
     
     
         13 . The inhaler of  claim 12  wherein the duct connects into the staging chamber adjacent to the closed off bottom surface.  
     
     
         14 . The inhaler of  claim 7  further including a mouthpiece connecting to the mixing chamber and wherein the duct provides the only connection between the staging chamber and the mixing chamber, such that all air entering into the mixing chamber via the duct, upon inhalation on the mouthpiece by a user of the inhaler, comes from the staging chamber.  
     
     
         15 . The inhaler of  claim 7  wherein the duct has a round cross section.  
     
     
         16 . The inhaler of  claim 15  wherein the duct has a length greater than its diameter.  
     
     
         17 . The inhaler of  claim 7  with the housing having a flat top surface and the duct extends in a direction parallel to the flat top surface.  
     
     
         18 . The inhaler of  claim 7  wherein the duct is longer than the inlet.