Details for Patent: 6,553,988

Title:	Medicament dispensing device with a multimaterial diaphragm bounding a pneumatic force chamber
Abstract:	A metered dose inhaler for use with a pressurized aerosol container which is preferably breath-actuated. A preload (80) is applied to the internal aerosol valve by an amount sufficient to result in a dose release, but this is prevented by the application of a pneumatic resisting force (130). The inhaler comprises a release device (110) which, upon actuation, releases the resisting force and allows the preload to actuate the aerosol valve (135). A metered dose of medicament is then released for inhalation by the patient. The pneumatic resisting force is established by a negative pressure region defined in part by a diaphragm. The diaphragm includes a central disk of a first, relatively high stiffness material and a peripheral ring, coupled by a flexure of a second, relatively low stiffness material.
Inventor(s):	Holroyd; Michael John (Great Shetford, GB)
Assignee:	Norton Healthcare, Inc. (London, GB)
Filing Date:	Jun 09, 2000
Application Number:	09/591,321
Claims:	1. A breath actuated dispensing device for dispensing a medicant in a metered dose from an aerosol medicament container, said container being cylindrical and extending along a container axis between a first end and a second end, said container having a spring based aerosol valve at said first end responsive to an axial force above a predetermined threshold to release said metered dose, comprising: A. a housing disposed about a central axis and having a first end and a second end, said second end including a shoulder and an expulsion nozzle extending therethrough; B. a support sleeve disposed within said housing said sleeve being adapted for axial motion along said central axis, and being adapted to support said second end of said container whereby said container axis is substantially coaxial with said central axis and said aerosol valve is positioned adjacent said shoulder and in communication with said expulsion nozzle; C. a diaphragm assembly including a relatively rigid central disk, a peripheral attachment ring disposed about a peripheral portion of said disk, and an annular flexure extending between said peripheral portion of said disk and said peripheral attachment ring, wherein said central disk is affixed to said first end of said housing and said peripheral attachment ring is affixed to said sleeve, thereby defining a closed region between said diaphragm and said sleeve; D. a breath actuated valve assembly adapted to selectively establish in a first state an air flow path between said closed region and regions exterior thereto, and interrupting in a second state said air flow path; E. a spring force bias element adapted to bias said sleeve toward said second end of said housing whereby when said breath actuated valve element is in said second state, pneumatic pressure in said closed region establishes a force on said sleeve equal to and opposite said bias whereby said axial force on said aerosol valve is below said predetermined threshold, and whereby when said breath actuated valve element is in said first state, pneumatic pressure in said closed region establishes a zero force on said sleeve and said bias is sufficient to drive said sleeve and said container toward said shoulder and establish an axial force on said aerosol valve above said predetermined threshold, wherein said central disk is made of a first material characterized by a relatively high stiffness, and said annular flexure is made of a second material characterized by a relatively low stiffness, and wherein said annular flexure is bonded to said disk, wherein the first material differs from the second material, whereby said disk, said annual flexure and said peripheral attachment ring form a contiguous assembly. 2. A dispensing device according to claim 1, wherein said peripheral ring is made of said second material. 3. A dispensing device, for use with an aerosol medicament container, for dispensing a medicant in metered doses comprising: a main body with a first and second end; a sleeve comprising sides and a base; a diaphragm assembly comprising a valve port operationally connected to said second end of said main body and said base of said sleeve; a spring operationally positioned in said second end of said main body so as to apply a preload force to said sleeve; and a vane operationally attached to said diaphragm wherein said vane has first and second positions, wherein when said vane is in said first position said vane seals said valve port and when said vane is in said second position said valve port is unsealed; wherein diaphragm assembly includes a relatively rigid central disk, a peripheral attachment ring disposed about a peripheral portion of said disk, and an annular flexure extending between said peripheral portion of said disk and said peripheral attachment ring, wherein said central disk is affixed to said first end of said main body and said peripheral attachment ring is affixed to said sleeve, thereby defining a closed region between said diaphragm and said sleeve; and wherein said central disk is made of a first material characterized by a relatively high stiffness, and said annular flexure is made of a second material characterized by a relatively low stiffness, and wherein said annular flexure is bonded to said disk, wherein the first material differs from the second material, whereby said disk, said annular flexure and said peripheral attachment ring form a contiguous assembly. 4. A dispensing device as claimed in claim 3, further comprising air inlets disposed in said second end of said main body. 5. A dispensing device as claimed in claim 3, further comprising a mouthpiece integrally formed in said first end of said main body. 6. A dispensing device as claimed in claim 3, further comprising: a dust cap pivotally attached to said first end of said main body capable of covering said mouthpiece wherein said dust cap comprises a cam; and a cam follower disposed in said main body and operationally connected between said cam and said sleeve. 7. A dispensing device comprising: a drug delivery system comprising a dispensing container capable of dispensing a metered dose; a main body; a releasing means for releasing a metered dose; a sleeve within said main body and capable of receiving said dispensing container; wherein said releasing means comprises a means for applying a preload force to said sleeve and capable of actuating said container in said system, a preventative force means for applying a resisting pneumatic force to said sleeve capable of preventing actuation of said container, and a release device capable of freeing said resisting pneumatic force to actuate said delivery system and dispense said metered dose; wherein said preventive force means includes a relatively rigid central disk, a peripheral attachment ring disposed about a peripheral portion of said disk, and an annular flexure extending between said peripheral portion of said disk and said peripheral attachment ring, wherein said central disk is affixed to said main body and said peripheral attachment ring is affixed to said sleeve, thereby defining a closed region between said diaphragm and said sleeve; and wherein said central disk is made of a first material characterized by a relatively high stiffness, and said annular flexure is made of a second material characterized by a relatively low stiffness, and wherein said annular flexure is bonded to said disk, wherein the first material differs from the second material, whereby said disk, said annular flexure and said peripheral attachment ring form a contiguous assembly.