Internal cannula mounted nebulizer
Provided herein are devices, systems, and methods for providing respiratory therapy to a patient using a nasal cannula comprising a cannula body, first and second inlet tubes, and a nasal prong for the delivery of a flow of breathing gas to the patient. Configured with the cannula is a nebulizer having an aerosol generator positioned to emit aerosolized medicament along a longitudinal axis of the nasal prong. A flow director is configured to direct the flow of breathing gas into the nasal prong such that the breathing gas flows along the longitudinal axis, such that the flow of aerosolized medicament is contained within the flow of breathing gas as it moves along the longitudinal axis of the nasal prong for delivery to the patient.
1 . A system for delivery of breathing gas and aerosolized medicament to a patient, the system comprising:
a delivery tube configured to supply a flow of breathing gas;
a nebulizer configured to supply a flow of nebulized medicament; and
a nasal interface having a first inlet, a second inlet, a mixing chamber in fluid communication with the first inlet and the second inlet, and an outlet in fluid communication with the mixing chamber to deliver a mixed flow of breathing gas and nebulized medicament, wherein the first inlet is coupled to a distal end of the delivery tube to receive the flow of breathing gas into the mixing chamber, and wherein the second inlet is coupled to an emitter of the nebulizer to receive the flow of nebulized medicament directly into the mixing chamber, the nasal interface further comprising a flow director having a first portion and a second portion;
wherein the mixing chamber and the second inlet are aligned with a longitudinal axis of the outlet, such that mixing of the flow of breathing gas and the flow of nebulized medicament occurs directly behind the outlet and along a direction coaxial with the longitudinal axis, the second inlet positioned along the longitudinal axis at a point at which the flow of breathing gas has a theoretical zero flow rate, and
wherein the first portion of the flow director is coupled to the nasal interface and adapted to receive the flow of breathing gas from the first inlet and direct the flow of breathing gas into the mixing chamber such that the breathing gas flows along the longitudinal axis, and the second portion is secured to the nebulizer and configured such that the flow of nebulized medicament is contained within the flow of breathing gas as it moves along the longitudinal axis of the outlet for delivery to the patient.
2 . The system of claim 1 , wherein the outlet is a nasal prong.
3 . The system of claim 2 , wherein the nasal prong has a hyperbolic or parabolic cross section.
4 . The system of claim 1 , wherein the breathing gas flows into the outlet along a path having a breathing gas axis that is symmetric along the longitudinal axis.
5 . The system of claim 1 , wherein the flow director forms an annular gap along a breathing gas flow path between the first inlet and the mixing chamber.
6 . The system of claim 5 , wherein the flow director is configured such that the flow of breathing gas has a pressure drop in the nasal interface that is largest across the annular gap.
7 . The system of claim 6 , wherein the pressure drop in the flow of breathing gas across the annular gap is at least 30%.
8 . The system of claim 5 , wherein the flow of breathing gas passes through the annular gap with a flow velocity that is constant at any point along the annular gap.
9 . The system of claim 1 , wherein the flow of breathing gas is axisymmetric about the longitudinal axis of the nasal prong up to the point of theoretical zero flow rate, after which the flow is axially orientated with respect to the longitudinal axis.
10 . The system of claim 9 , wherein the flow of breathing gas about the longitudinal axis up to the point of theoretical zero flow rate is radial, substantially radial or directed towards the longitudinal axis.
11 . The system of claim 9 , wherein the flow of breathing gas about the longitudinal axis of the nasal prong up to the point of theoretical zero flow rate forms a shape that is any one of conical, hyperbolic, parabolic and circular.
12 . The system of claim 1 , wherein the flow director further comprises an anti-rotation element which prevents rotation of the flow of breathing gas within the nasal interface as it is supplied via the first inlet.
13 . The system of claim 12 , wherein the anti-rotation element comprises a plurality of baffles symmetrically arranged about the flow director.
14 . The system of claim 1 , wherein the nebulizer is removably attached to the nasal interface.
15 . The system of claim 1 , wherein the emitter of the nebulizer comprises a vibrating mesh.
16 . The system of claim 15 , wherein the vibrating mesh is attached to a piezoelectric element.
17 . The system of claim 16 , wherein the piezoelectric element is in electrical contact with a controller on a printed circuit board.
18 . The system of claim 17 , wherein the piezoelectric element is in electrical contact with the printed circuit board via spring contact pins.
19 . The system of claim 18 , further comprising wires that are in electrical contact with the printed circuit board for transmitting electrical signals from a signal generator to the vibrating mesh.
20 . The system of claim 19 , wherein the wires are threaded through the delivery tube.
21 . The system of claim 20 , further comprising a housing that is attached to the nasal interface.
22 . The system of claim 21 , wherein the housing comprises injection molded plastic.
23 . The system of claim 21 , wherein the housing is attached to the nasal interface using a snap-fit connection.
24 . The system of claim 21 , wherein the housing contains a reservoir filled with liquid medicament, the reservoir arranged such that the liquid medicament is in contact with an inner surface of the vibrating mesh.
25 . The system of claim 24 , wherein the housing contains O-rings to achieve a liquid tight seal between the vibrating mesh and the housing.
26 . The system of claim 24 , wherein the flow of aerosolized medicament is emitted from an outer surface of the emitter.
27 . The system of claim 24 , wherein the reservoir is in fluid communication with a liquid feed line.
28 . The system of claim 27 , wherein the liquid feed line is threaded through the delivery tube.
29 . The system of claim 28 , wherein the liquid feed line comprises micro-bore tubing.
30 . The system of claim 1 , wherein the delivery tube is in fluidic communication with a source of breathing gas.
31 . The system of claim 1 , wherein the nasal interface comprises a soft rubber, a rubber-like material, molded silicone, a thermoplastic elastomer (TPE), or dip molded polyvinyl chloride (PVC).
32 . The system of claim 1 , wherein the medicament comprises at least one of: bronchodilators, surfactants and antibiotics.
33 . The system of claim 1 , wherein the liquid medicament comprises at least one of: Albuterol (Ventolin), Salbutamol (Proventil), Levosalbutamol/Levalbuterol (Xopenex), Curosurf (Chiesi Pharmaceuticals), Alveofact (Boehringer Ingelheim), Survanta (Abbott Laboratories), Exosurf (Glaxo Wellcome), Surfaxin (Discovery Laboratories), macrolides, erythromycin, clarithromycin, azithromycin, glycopeptides, vancomycin, teicoplanin, oxazoldinone, quinupristin/dalfopristen, aminoglycosides, gentamicin, tobramycin, amikacin, streptomycin, netilmicin, quinolones, ciprofloxacin, ofloxacin, levofloxacin, tetracyclines, oxytetracycline, doxycycline, minocycline, cotrimoxazole, colistin, imepinim, meripenim, pumactant, lucinactant, poractant alfa, beractant, calfactant, Beraksurf, Venticute, and colfosceril palmitate.