Cough-assist systems with humidifier bypass

1. A system comprising:

a cough-assist device having a first phase configured to provide insufflating gas to a patient circuit and a second phase configured to draw exsufflating gas from the patient circuit;

a humidifier between the cough-assist device and a distal end of the patient circuit, the humidifier comprising a chamber (i) configured to contain water and/or water vapor and (ii) fluidically coupled to the cough-assist device and the patient circuit; and

a bypass configured to direct insufflating gas from the ventilator through to the patient circuit such that the insufflating gas is humidified in the chamber, wherein the bypass is further configured to route exsufflating gas from the patient circuit to the cough-assist device such that at least a portion of the exsufflating gas bypasses the chamber when the chamber is fluidically coupled to the cough-assist device and the patient circuit, wherein the bypass comprises a first conduit extending away from the chamber and fluidically coupling the cough-assist device to the chamber, a second conduit extending away from the chamber and fluidically coupling the chamber to the distal end of the patient circuit, a bridge connecting and extending between the first conduit and the second conduit, the bridge spaced apart from the chamber, a first valve disposed in the first conduit at a position between the chamber and the bridge, and a second valve disposed in the bridge at a position between the first conduit and the second conduit.

2. The system of claim 1 wherein the cough-assist device comprises a ventilator configured to provide breathing assistance in a first mode and cough assistance in a second mode.

3. The system of claim 1 wherein the first valve is configured

to (a) open in the presence of insufflating gas so that insufflating gas from the cough-assist device passes through the chamber and (b) close in the presence of exsufflating gas to prevent exsufflating gas from exiting the chamber; and

the second valve is configured to (a) open in the presence of exsufflating gas from the patient circuit so that at least the portion of the exsufflating gas passes to the ventilator without passing through the chamber and (b) to close in the presence of insufflating gas.

4. The system of claim 1 wherein the first valve is a one-way valve configured to open towards the chamber in the presence of insufflating gas, and wherein the second valve is a one-way valve configured to open towards the first conduit in the presence of exsufflating gas.

5. A humidifier assembly, comprising: a chamber configured to retain liquid therein; a heater configured to deliver heat to liquid within the chamber; a first conduit extending away from the chamber and configured to fluidically couple a cough-assist device to the chamber; a second conduit extending away from the chamber and configured to fluidically couple the chamber to a patient circuit; a bridge connecting and extending between the first conduit and the second conduit, the bridge spaced apart from the chamber; an insufflation flowpath configured to receive insufflating gas from a cough-assist device and direct the insufflating gas through the chamber and to a patient circuit; and an exsufflation flowpath configured to receive exsufflating gas from the patient circuit and direct at least a portion of the exsufflating gas to the cough-assist device without passing through the chamber when the humidifier assembly is fluidically coupled to the cough-assist device and the patient circuit, wherein the chamber is positioned between the first conduit and the second conduit, and wherein both the insufflating gas and the exsufflating gas are routed through at least a portion of the first conduit and at least a portion of the second conduit.

6. A system comprising:

a cough-assist device having an insufflating module configured to provide an insufflating gas flow to a patient circuit and an exsufflating module configured to draw an exsufflating gas flow from the patient circuit;

a humidifier fluidically coupled to the cough-assist device and the patient circuit, the humidifier having a chamber configured to contain water and/or water vapor; and

a bypass having a first flow path between the cough-assist device and the chamber, a second flow path between the chamber and the patient circuit, a third flow path between the first and second flow paths, and a valve system, wherein the valve system is configured to—

(a) block the third flow path during insufflation so that the insufflation gas flow passes through the chamber via the first and second flow paths, and

(b) open the third flow path and block the first flow path during exsufflation such that at least a portion of the exsufflation gas flow passes through the third flow path and bypasses the chamber when the humidifier is fluidically coupled to the cough-assist device and the patient circuit.

7. The system of claim 6 wherein the valve system comprises:

a first passive valve in the first flow path between the chamber and an intersection between the first flow path and the third flow path; and

a second passive valve in the third flow path.

8. The system of claim 7 wherein the first passive valve comprises a first check valve configured to open towards the chamber during insufflation, and wherein the second passive valve comprises a second check valve configured to open towards the first flow path during exsufflation.

9. The system of claim 6 wherein the valve system comprises a valve disposed in the first flow path at an intersection between the first flow path and the third flow path, the valve configured to:

(a) block the third flow path during insufflation so that the insufflation gas flow passes into the chamber via the first flow path, and

(b) open the third flow path and block the first flow path during exsufflation such that at least the portion of the exsufflation gas flow passes through the third flow path and bypasses the chamber.

10. A humidifier assembly, comprising:

a chamber configured to retain liquid therein;

a heater configured to deliver heat to liquid within the chamber; and a bypass, wherein the bypass comprises: a first conduit extending away from the chamber and configured to fluidically couple a cough-assist device to the chamber; a second conduit extending away from the chamber and configured to fluidically couple the chamber to a patient circuit; a bridge connecting and extending between the first conduit and the second conduit, the bridge spaced apart from the chamber; a first valve disposed in the first conduit at a position between the chamber and the bridge; a second valve disposed in the bridge at a position between the first conduit and the second conduit

an insufflation flowpath configured to receive insufflating gas from a cough-assist device and direct the insufflating gas through the chamber and to a patient circuit; and

an exsufflation flowpath configured to receive exsufflating gas from the patient circuit and direct at least a portion of the exsufflating gas to the cough-assist device without passing through the chamber when the humidifier assembly is fluidically coupled to the cough-assist device and the patient circuit.

11. The humidifier assembly of claim 10 ,

wherein the insufflation flowpath passes through the first valve.

12. The humidifier assembly of claim 11 wherein the exsufflation flowpath does not pass through the first valve.

13. The humidifier assembly of claim 11 ,

wherein the exsufflation flowpath passes through the second valve.

14. The humidifier assembly of claim 13 wherein the insufflation flowpath does not pass through the second valve.

15. A method for providing cough assistance to a patient, the method comprising:

delivering insufflating gas from a cough-assist device to a patient via a patient circuit, wherein the patient circuit has a first conduit and a second conduit; and

withdrawing exsufflating gas from the patient via the patient circuit, wherein at least a portion of the exsufflating gas bypasses a humidifier fluidically coupled to the cough-assist device and the patient circuit before reaching the cough-assist device, wherein the humidifier is positioned between the first conduit and second conduit, and wherein both the insufflating gas and exsufflating gas are routed through at least a portion of the first conduit and at least a portion of the second conduit.

16. The method of claim 15 wherein withdrawing exsufflating gas comprises providing a pressure between negative 30-70 cm H 2 O in the patient circuit.

17. The method of claim 15 wherein delivering insufflating gas comprises passing the insufflating gas through a chamber in the humidifier, thereby humidifying the insufflating gas before it reaches the patient.

18. The method of claim 15 wherein withdrawing the exsufflating gas comprises passing at least a portion of the exsufflating gas through a bypass coupled to the humidifier.

19. The method of claim 18 wherein the bypass comprises:

a first valve configured to (a) open while delivering the insufflating gas so that the insufflating gas from the cough-assist device passes through a chamber in the humidifier and (b) close in the presence of exsufflating gas to prevent exsufflating gas from exiting the chamber; and

a second valve configured to (a) open while withdrawing the exsufflating gas from the patient circuit so that at least the portion of the exsufflating gas passes to the ventilator without passing through the chamber and (b) to close in the presence of insufflating gas.