Inhalation device and method
The invention relates to the field of inhalation devices for liquids. In particular, the invention relates to an inhalation device having improved flow characteristics. A inhalation device for medically active liquids (F) for generation of an aerosol comprises a housing ( 1 ), inside this housing ( 1 ) a reservoir ( 2 ) for storing a liquid (F), a pumping device with a hollow cylinder ( 9 ) providing a pumping chamber ( 3 ) for the generation of a pressure inside said pumping chamber ( 3 ), wherein the pumping chamber is fluidically connected with the reservoir ( 2 ) via an inlet check valve ( 4 ) which blocks in direction of the reservoir ( 2 ), a riser pipe ( 5 ) which can be received with at least one reservoir-facing, interior end ( 5 A) in said hollow cylinder ( 9 ), and a nozzle ( 6 ) which is connected liquid-tight to an exterior end ( 5 B) of the riser pipe ( 5 ), wherein the volume of the pumping chamber ( 3 ) is changeable by means of relative motion of the cylinder ( 9 ) to the riser pipe ( 5 ), and is characterised in that the riser pipe ( 5 ) is immobile and firmly attached to the housing ( 1 ) and to the nozzle ( 6 ), whereas the hollow cylinder ( 9 ) is moveable relative to the housing ( 1 ) and to the nozzle ( 6 ). The invention also discloses a method for the generation of an aerosol of a medically active liquid (F) by means of an inhalation device.
1. A hand-held inhalation device for delivering a nebulised medically active aerosol for inhalation therapy, comprising
(a) a housing having a user-facing side;
(b) an impingement-type nozzle for generating the nebulised aerosol by collision of at least two liquid jets, the nozzle being firmly affixed to the user-facing side of the housing such as to be immobile relative to the housing;
(c) a fluid reservoir arranged within the housing; and
(d) a pumping unit arranged within the housing, the pumping unit having
an upstream end that is fluidically connected to the fluid reservoir;
a downstream end that is fluidically connected to the nozzle;
wherein the pumping unit is adapted for pumping fluid from the fluid reservoir to the nozzle;
wherein the pumping unit further comprises
(i) a riser pipe having an upstream end, wherein the riser pipe is
adapted to function as a piston in the pumping unit, and
firmly affixed to the user-facing side of the housing such as to be immobile relative to the housing; and
(ii) a hollow cylinder fluidly connected with the fluid reservoir and located upstream of the riser pipe, wherein the upstream end of the riser pipe is inserted in the cylinder such that the cylinder is longitudinally movable on the riser pipe;
(iii) a means for storing potential energy when loaded and for releasing the stored energy when released, the means being arranged outside of, and mechanically coupled to, the cylinder such that releasing the means results in a propulsive longitudinal movement of the cylinder towards the downstream end of the pumping unit; wherein the pumping unit is a high-pressure pumping unit adapted to expel fluid at a pressure of at least 50 bar.
2. The inhalation device according to claim 1 , wherein the means for storing potential energy is a spring having a load of at least 10 N in a deflected state.
3. The inhalation device according to claim 2 , wherein a unit of the aerosol contains from 2 to 150 μl of liquid phase.
4. The inhalation device according to claim 1 , being adapted to deliver the nebulised medically active aerosol discontinuously in the form of discrete units, wherein one unit is delivered per pumping cycle.
5. The inhalation device according to claim 1 , wherein the pumping unit further comprises an inlet valve positioned at or near the upstream end of the hollow cylinder.
6. The inhalation device according to claim 5 , wherein the inlet valve is adapted to open only when the pressure difference between an upstream and a downstream side of the inlet valve is above a predefined threshold value, and wherein the predefined threshold value is in the range from 1 to 20 mbar.
7. The inhalation device according to claim 1 , further comprising an outlet valve inside the riser pipe for avoiding a return flow of liquid or air from the riser pipe into the hollow cylinder.
8. The inhalation device according to claim 1 , wherein the fluid reservoir is firmly attached to the hollow cylinder such as to be moveable together with the hollow cylinder inside the housing.
9. The inhalation device according to claim 1 , wherein the fluid reservoir is fluidically connected to the hollow cylinder by means of a flexible tubular element, and firmly attached to the housing.
10. The inhalation device according to claim 1 , wherein the fluid reservoir is designed as a collapsible bag.
11. A method for the generation of a nebulised aerosol of a medically active liquid comprising the steps of:
providing the hand-held inhalation device as defined in claim 1 , wherein the fluid reservoir of the inhalation device comprises said medically active liquid, and wherein the means for storing potential energy is in a released state;
priming said inhalation device by causing the state of the means for storing potential energy to be altered from the released state to a loaded state, whereby the hollow cylinder performs a repulsive longitudinal movement on the riser pipe towards the upstream end of the pumping unit such as to allow medically active liquid to flow from the fluid reservoir into the hollow cylinder; and subsequently
actuating said inhalation device by causing the means for storing potential energy to become released, whereby a propulsive longitudinal movement of the cylinder towards the downstream end of the pumping unit is effected and medically active liquid is ejected in a downstream direction from the hollow cylinder through the nozzle.
12. The hand-held inhalation device according to claim 1 , wherein the hollow cylinder is directly connected with the fluid reservoir.
13. The hand-held inhalation device according to claim 1 , wherein the hollow cylinder is indirectly connected with the fluid reservoir.