Flow governors for use in medicinal inhalers
A flow governor for use in a medicinal inhaler. The flow governor can include (i) a tubular element that defines at least a portion of an air flow path, the tubular element comprising at least one flexible wall configured to flex inwardly in response to an air flow in the air flow path; and (ii) an internal support structure, located within the tubular element and configured to preserve at least a predetermined cross-sectional area of the air flow path within the tubular element when the at least one flexible wall of the tubular element flexes inwardly.
1. A flow governor for use in a medicinal inhaler, the flow governor comprising:
a tubular element that defines at least a portion of an air flow path, the tubular element comprising at least one flexible wall configured to flex inwardly in response to an air flow in the air flow path; and
an internal support structure, located within the tubular element and configured to preserve at least a predetermined cross-sectional area of the air flow path within the tubular element when the at least one flexible wall of the tubular element flexes inwardly, wherein the internal support structure includes a hollow pillar defining a lumen therein, and further wherein the predetermined cross-sectional area of the air flow path includes a cross-sectional area of space between the tubular element and the internal support structure.
2. The flow governor of claim 1 , wherein the tubular element is substantially bistable between an uncollapsed state and a collapsed state.
3. The flow governor of claim 1 , wherein the internal support structure is rigid relative to the tubular element, and the tubular element is flexible relative to the internal support structure.
4. The flow governor of claim 1 , wherein the internal support structure has a base having an outer wall, and wherein an end of the tubular element is stretched over the outer wall of the base of the internal support structure.
5. The flow governor of claim 1 , wherein the air flow path through the flow governor includes the space between an outer wall of the internal support structure and the tubular element, and the lumen of the hollow pillar.
6. The flow governor of claim 1 , wherein the internal support structure includes a transverse cross-sectional shape comprising at least one of the capital English letters selected from B, C, D, E, H, M, N, O, S, V, W, X and Z.
7. The flow governor of claim 1 , wherein the internal support structure includes at least one solid pillar.
8. The flow governor of claim 1 , wherein the internal support structure further includes a second pillar, wherein each pillar is oriented substantially parallel to a longitudinal direction of the tubular element, and a cross member positioned to couple the two pillar and the second pillar, the cross member oriented at a non-zero angle with respect to the longitudinal direction.
9. The flow governor of claim 8 , wherein the second pillar is a hollow pillar defining a lumen therein.
10. The flow governor of claim 1 , wherein the internal support structure includes at least one rib that protrudes substantially orthogonally with respect to the at least one flexible wall of the tubular element.
11. A medicinal inhaler comprising at least one flow governor of claim 1 positioned in fluid communication with an air flow path of the medicinal inhaler.
12. The medicinal inhaler of claim 11 , wherein the medicinal inhaler is a pressurized metered dose inhaler (pMDI).
13. The medicinal inhaler of claim 11 , wherein the at least one flow governor is positioned in a dedicated air flow path of the medicinal inhaler, wherein the dedicated air flow path includes an air inlet open to ambience and an air outlet in fluid communication with the air flow path of the inhaler, and wherein the at least one flow governor is positioned between the air inlet and the air outlet of the dedicated air flow path.
14. The medicinal inhaler of claim 11 , further comprising a pressure sensor located in the air flow path of the medicinal inhaler and upstream of the at least one flow governor.
15. A medicinal inhaler comprising at least two flow governors of claim 1 positioned in fluid communication with an air flow path of the medicinal inhaler and arranged in parallel.
16. A medicinal inhaler comprising at least two flow governors of claim 1 positioned in fluid communication with an air flow path of the medicinal inhaler and arranged in series.
17. A medicinal inhaler comprising:
a housing comprising
a tubular sleeve portion dimensioned to receive a canister comprising a medicament, and
a patient port;
an air flow path including an air inlet and an air outlet, wherein the air outlet is defined by the patient port; and
the flow governor of claim 1 positioned in the air flow path of the medicinal inhaler.