Ventilator With Controlled Purge Function

• US 20100051026A1
• Filed: 09/03/2009
• Published: 03/04/2010
• Est. Priority Date: 09/04/2008
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Graboi, Daniel G.
• Application Number:
  US12/553,576
• Publication Number:
  US 20100051026A1
• Time in Patent Office: Days
• US Class Current: 128/203.120
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/085 Gas sampling
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 2016/0027 pressure meter

Abstract

This disclosure describes systems and methods for purging narrow diameter sensor tubing in a ventilation system. Among other aspects, this disclosure describes ventilation systems in which a sensor tube purge module utilizes a ventilator-generated signal to synchronize the purging of sensor tubes with the delivery of respiratory therapy. Through the signal, purging is prevented from occurring during inspiration and during events such as ventilation maneuvers. Purging may be further improved by monitoring the pressure of the gas used to purge the sensor tubes in order to prevent purges being performed when the pressure is too high or too low. One way to achieve this is by purging the sensor tubes using gas discharged from an accumulator, in which the pressure in the accumulator is monitored and controlled by the sensor tube purging module.

Claims

1. A pressure support system comprising:

a pressure generating system adapted to generate a flow of breathing gas;

a ventilation system including a patient circuit adapted to control delivery of the flow of breathing gas;

at least one circuit sensor in fluid communication with the patient circuit via one or more sensor tubes; and

a sensor tube purge module adapted to discharge gas through the sensor tube into the patient circuit based on a signal received from the ventilation system.

2. The system of claim 1 wherein the signal received is a purge-enable signal and the sensor tube purge module discharges gas based on the purge-enable signal and one or more conditions determined by the sensor tube purge module.

3. The system of claim 2 wherein the one or more conditions are selected from an elapsed time since a last discharge of gas though the sensor tube, a monitored gas pressure, an indication of a breathing cycle of a patient connected to the patient circuit, a user-generated command to discharge gas, and an elapsed number of breaths since the last discharge of gas through the sensor tube.

4. The system of claim 2 wherein when the purge-enable signal indicates that a purge can be performed, the sensor tube purge module discharges gas based one or more conditions determined by the sensor tube purge module.

5. The system of claim 2 wherein when the purge-enable signal indicates that a purge can not be performed, the sensor tube purge module does not discharge gas.

6. The system claim 1 wherein the sensor tube purge module transmits information to the ventilation system after each discharge indicative of the amount of gas discharged into the patient circuit.

7. The system of claim 6 wherein the information transmitted is selected from one or more of a volume of gas discharged, an indication that a discharge was performed, a discharge duration, and a pressure associated with the discharged gas.

8. The system of claim 1 wherein the sensor tube purge module further comprises:

an accumulator from which gas is discharged through the one or more sensor tubes; and

an accumulator pressure monitoring device.

9. The system of claim 8 wherein the sensor tube purge module discharges gas based on the signal received from the ventilation system and the accumulator pressure.

10. The system of claim 1 wherein the signal received is a purge command signal directing the sensor tube purge module to discharges gas and, in response, the sensor tube purge module discharges gas upon a next detection of the end of patient inspiration.

11. The system of claim 1 wherein the signal received is a recruitment maneuver signal indicating when the ventilation system is performing a recruitment maneuver and the sensor tube purge module does not discharge gas when the recruitment maneuver signal indicates that a recruitment maneuver is ongoing.

12. A pressure support system comprising:

a ventilation system controlling the flow of breathing gas in a patient circuit;

a sensor in fluid communication with the patient circuit via one or more sensor tubes; and

a sensor tube purge module adapted to discharge gas through the sensor tube into the ventilation system based on the flow of breathing gas in the patient circuit.

13. The system of claim 12 wherein the sensor tube purge module monitors the patient'"'"'s breathing via the sensor and discharges gas through a sensor tube only during a predetermined phase of a patient'"'"'s breathing cycle as determined by the sensor tube purge module.

14. The system of claim 12 wherein the ventilation system monitors the patient'"'"'s breathing and the sensor tube purge module discharges gas through a sensor tube only during a predetermined phase of a patient'"'"'s breathing cycle as determined by the ventilation system.

15. The system of claim 14 wherein the ventilation system transmits a signal to the sensor tube purge module indicative of the patient'"'"'s breathing cycle.

16. The system of claim 14 wherein the ventilation system transmits a signal to the sensor tube purge module indicative of the predetermined phase of the patient'"'"'s breathing cycle.

17. A pressure support system comprising:

a pressure generating system adapted to generate a flow of breathing gas;

a ventilation system including a patient circuit;

a sensor in fluid communication with the patient circuit via a sensor tube; and

a sensor tube purge module having a controller, an accumulator from which gas is discharged through the one or more sensor tubes, and an accumulator pressure monitoring device, wherein the sensor tube purge module is adapted to discharge gas from the accumulator through the sensor tube into the patient circuit.

18. The system of claim 17 wherein the sensor tube purge module charges the accumulator to a predetermined pressure prior to discharging gas from accumulator through the sensor tube into the ventilation system.

19. The system of claim 17 wherein the sensor tube purge module monitors changes in the accumulator pressure over time.

20. The system of claim 17 wherein the sensor tube purge module transmits an alarm notification based on the monitored changes in pressure during a time period when the sensor tube purge module is not actively discharging gas through the sensor tube.

21. The system of claim 17 wherein the sensor tube purge module transmits information derived from an output the accumulator pressure monitoring device for display by the ventilation system.

22. The system of claim 17 wherein the sensor tube purge module further comprises:

a pump that pressurizes the accumulator.

23. The system of claim 17 wherein the sensor tube purge module further comprises:

a regulator connected to an external source of pressurized gas that pressurizes the accumulator.

24. The system of claim 17 wherein the ventilation system monitors a patient'"'"'s breathing cycle and the sensor tube purge module discharges gas through a sensor tube only during a predetermined phase of a patient'"'"'s breathing cycle.

25. A method of purging a sensor tube connecting a sensor to a gas transport circuit comprising:

monitoring a pressure or flow in the gas transport circuit using the sensor; and

discharging a volume of gas through the sensor tube into the gas transport circuit based at least in part on the monitored pressure or flow in the gas transport circuit.

26. The method of claim 25 wherein the gas transport circuit is a patient circuit connected to a breathing patient and the method further comprises:

determining a current phase of a breathing cycle of the patient from the monitored pressure or flow; and

discharging the volume of gas through the sensor tube into the patient circuit based at least in part on the current phase of the breathing cycle of the patient.

27. The method of claim 26 wherein the discharging operation further comprises:

discharging only when the current phase of the breathing cycle is not an inhalation phase.

28. The method of claim 26 further comprising:

discharging the volume of gas through the sensor tube into the patient circuit based on the current phase of the breathing cycle of the patient and a condition based on a last discharge of gas through the sensor tube.

29. The method of claim 28 wherein the condition based on a last discharge of gas through the sensor tube is selected from a time period since the last discharge of gas and a number of breaths since the last discharge of gas.

30. The method of claim 25 wherein the gas transport circuit is a patient circuit connected to a breathing patient and the method further comprises:

monitoring a signal provided by a ventilation system controlling the flow of gas in the patient circuit, wherein signal is indicative of the flow of gas in the patient circuit and generated by the ventilation system based at least in part on the monitored pressure or flow in the gas transport circuit; and

discharging the volume of gas through the sensor tube into the patient circuit based at least in part on the signal from the ventilation system.

31. The method of claim 25 wherein the signal is selected from a purge-enable signal, a recruitment maneuver signal, a signal indicating a condition of the ventilator, and a signal indicating a phase of a patient'"'"'s breathing cycle.

32. The method of claim 25 further comprising:

transmitting information identifying the volume of gas discharged through the sensor tube into the gas transport circuit.

33. A ventilation system adapted to generate a purge control signal to a sensor tube purge module thereby controlling, at least in part, when the sensor tube purge module purges the sensor tubes.

34. The system of claim 33 wherein the purge control signal indicates to the sensor tube purge module when a purge of the sensor tubes can be performed.

35. The system of claim 33 wherein the purge control signal indicates to the sensor tube purge module when to purge the sensor tube.

36. The system of claim 33 wherein the purge control signal indicates to the sensor tube purge module when purging of the sensor tube is not allowed.

37. A sensor tube purge module adapted to discharge gas through a sensor tube into a gas transport circuit comprising:

a pressure generating system adapted to discharge a volume of gas through the sensor tube into the gas transport circuit; and

a controller controlling the discharge of gas from the pressure generating system, the controller further adapted to communicate with a ventilation system that controls the flow of gas in the gas transport circuit.

38. The sensor tube purge module of claim 37 wherein the controller is adapted to receive one or more signals from the ventilation system, wherein the signals are selected from a signal indicating when discharge of gas through the sensor tubes is not allowed, a signal indicating when discharge of gas through the sensor tubes is allowed, and a signal indicating when to discharge gas through the sensor tubes.

39. The sensor tube purge module of claim 37 wherein the controller is adapted to transmit information to the ventilation system based on the discharge of gas through the sensor tubes, wherein the information is selected from one or more of a volume of gas discharged, an indication that a discharge was performed, a discharge duration, and a pressure associated with the discharged gas.

40. The sensor tube purge module of claim 37 further comprising:

a sensor attached to the sensor tubes, wherein the sensor monitors pressure or flow in the gas transport circuit and transmits information indicative of the pressure or flow to the ventilator.

41. A pressure support system comprising:

a ventilation system adapted to deliver respiratory gas to a patient; and

a sensor tube purge means for synchronizing the purging of a sensor tube, with the delivery of gas to the patient by the ventilation system.