System for providing flow-targeted ventilation synchronized to a patient's breathing cycle

• US 8,015,974 B2
• Filed: 01/29/2008
• Issued: 09/13/2011
• Est. Priority Date: 01/26/2007
• Status: Active Grant

• Current Assignee: Fisher & Paykel Healthcare Limited
• Original Assignee: Cs Medical, Inc.
• Inventors: Diehl, Stephanie S., Christopher, Kent L.
• Primary Examiner(s): Yu; Justine
• Assistant Examiner(s): DIXON, ANNETTE FREDRICKA
• Application Number:
  US12/021,641
• Publication Number:
  US 20080178882A1
• Time in Patent Office: 1,323 Days
• Field of Search: 128/200.24, 128/200.26, 128/204.18, 128/204.21, 128/204.23, 128/207.14, 128/207.18
• US Class Current: 128/207.18
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/0878 using temperature sensing means
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0427 with removable and re-insertable liner tubes, e.g. for cleaning
• CPC Class Codes: A61M 16/0434 Cuffs
• CPC Class Codes: A61M 16/0461 Nasoendotracheal tubes
• CPC Class Codes: A61M 16/0465 Tracheostomy tubes; Devices for performing a tracheostomy; Accessories therefor, e.g. masks, filters
• CPC Class Codes: A61M 16/0488 Mouthpieces; Means for guiding, securing or introducing the tubes guiding or introducing with laryngoscopes A61B1/267; holding devices on the body A61M25/02
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0672 Nasal cannula assemblies for oxygen therapy
• CPC Class Codes: A61M 16/085 Gas sampling
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/10 Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 16/101 using an oxygen concentrator
• CPC Class Codes: A61M 16/1095 : in the connecting tubes
• CPC Class Codes: A61M 16/12 : by mixing different gases
• CPC Class Codes: A61M 16/125 : Diluting primary gas with ambient air
• CPC Class Codes: A61M 16/161 : with means for measuring the humidity
• CPC Class Codes: A61M 16/204 : used for inhalation control
• CPC Class Codes: A61M 16/208 : Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• CPC Class Codes: A61M 16/209 : Relief valves
• CPC Class Codes: A61M 2016/0021 : with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 : pressure meter
• CPC Class Codes: A61M 2016/0039 : in the inspiratory circuit
• CPC Class Codes: A61M 2016/0413 : with detectors of CO2 in exhaled gases
• CPC Class Codes: A61M 2016/1025 : the O2 concentration
• CPC Class Codes: A61M 2202/0208 : Oxygen
• CPC Class Codes: A61M 2202/025 : Helium
• CPC Class Codes: A61M 2202/0275 : Nitric oxide [NO]
• CPC Class Codes: A61M 2205/16 : with back-up system in case of failure
• CPC Class Codes: A61M 2205/18 : with alarm
• CPC Class Codes: A61M 2205/32 : with radio-opaque indicia
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/70 : with testing or calibration facilities
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/202 : partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/205 : partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/432 : partial CO2 pressure (P-CO2)
• CPC Class Codes: A62B 7/06 : with liquid oxygen or air; Cryogenic systems
• CPC Class Codes: A62B 7/08 : containing chemicals producing oxygen

Abstract

An open system provides breath-synchronized, flow-targeted ventilation to augment respiration by a self-breathing patient. A sensor detects a physical property of a patient'"'"'s respiratory cycle. A processor monitors the sensor and controls a gas source to deliver oxygen-containing gas through a tube extending into the patient'"'"'s airway with the flow rate varying over each respiratory cycle in a predetermined non-constant waveform synchronized with the respiratory cycle to augment the patient'"'"'s spontaneous respiration. Gas is delivered at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing.

Claims

1. An apparatus for delivering a flow of oxygen-containing gas to the airway of a spontaneously-breathing patient, said apparatus comprising:

a nasal tube delivering a flow of oxygen-containing gas into a patient'"'"'s airway without interfering with a patient'"'"'s spontaneous respiration;

a gas source delivering a variable flow of oxygen-containing gas through the nasal tube;

a sensor detecting a physical property of a patient'"'"'s respiratory cycle; and

a processor monitoring the sensor and controlling the gas source to deliver a flow of oxygen-containing gas through the nasal tube to augment the patient'"'"'s spontaneous respiration, said flow varying over each inspiratory and expiratory phase of the respiratory cycle in a predetermined non-constant flow waveform synchronized with the respiratory cycle, said waveform including;

(a) a positive flow accelerating at the onset of the patient'"'"'s inspiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing; and

(b) a positive flow during at least the early portion of the patient'"'"'s expiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing, and to wash carbon dioxide from the patient'"'"'s airway.

2. The apparatus of claim 1 wherein the sensor is attached to a portion of the nasal tube in a patient'"'"'s airway.

3. The apparatus of claim 1 further comprising a sampling tube extending along a portion of the nasal tube in a patient'"'"'s airway to the sensor.

4. The apparatus of claim 1 wherein the sensor comprises a pressure transducer.

5. The apparatus of claim 1 wherein the sensor comprises a flow sensor.

6. The apparatus of claim 1 wherein the sensor comprises a thermistor.

7. The apparatus of claim 1 wherein the sensor comprises a carbon dioxide sensor.

8. The apparatus of claim 1 wherein the nasal tube comprises a nasopharyngeal catheter.

9. The apparatus of claim 1 wherein the nasal tube comprises a nasal cannula.

10. The apparatus of claim 1 wherein the processor interrupts the flow for a portion of the respiratory cycle.

11. An apparatus for delivering a flow of oxygen-containing gas to the airway of a spontaneously-breathing patient, said apparatus comprising:

a nasal tube delivering a flow of oxygen-containing gas into a patient'"'"'s airway without interfering with a patient'"'"'s spontaneous respiration;

a gas source delivering a variable flow of oxygen-containing gas through the nasal tube;

a sensor attached to a portion of the nasal tube in a patient'"'"'s airway for detecting a physical property of a patient'"'"'s respiratory cycle; and

a processor monitoring the sensor and controlling the gas source to deliver a flow of oxygen-containing gas through the nasal tube to augment the patient'"'"'s spontaneous respiration, said flow varying over each inspiratory and expiratory phase of the respiratory cycle in a predetermined non-constant flow waveform synchronized with the respiratory cycle, said waveform including;

(a) a positive flow accelerating at the onset of the patient'"'"'s inspiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing; and

(b) a positive flow during at least the early portion of the patient'"'"'s expiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing, and to wash carbon dioxide from the patient'"'"'s airway.

12. The apparatus of claim 11 wherein the sensor comprises a flow sensor.

13. The apparatus of claim 11 wherein the sensor comprises a thermistor.

14. The apparatus of claim 11 wherein the nasal tube comprises a nasopharyngeal catheter.

15. The apparatus of claim 11 wherein the nasal tube comprises a nasal cannula.

16. The apparatus of claim 11 wherein the processor interrupts the flow for a portion of the respiratory cycle.

17. An apparatus for delivering a flow of oxygen-containing gas to the airway of a spontaneously-breathing patient, said apparatus comprising:

a nasal tube delivering a flow of oxygen-containing gas into a patient'"'"'s airway without interfering with a patient'"'"'s spontaneous respiration;

a gas source delivering a variable flow of oxygen-containing gas through the nasal tube;

a sensor for detecting a physical property of a patient'"'"'s respiratory cycle;

a sampling tube extending along at least a portion of the nasal tube into a patient'"'"'s airway to the sensor; and

a processor monitoring the sensor and controlling the gas source to deliver a flow of oxygen-containing gas through the nasal tube to augment the patient'"'"'s spontaneous respiration, said flow varying over each inspiratory and expiratory phase of the respiratory cycle in a predetermined non-constant flow waveform synchronized with the respiratory cycle, said waveform including;

(a) a positive flow accelerating at the onset of the patient'"'"'s inspiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing; and

(b) a positive flow during at least the early portion of the patient'"'"'s expiratory phase at a flow rate sufficient to significantly mitigate the airway pressure the patient must generate during spontaneous breathing and thereby reduce the patient'"'"'s work of breathing, and to wash carbon dioxide from the patient'"'"'s airway.

18. The apparatus of claim 17 wherein the sensor comprises a pressure transducer.

19. The apparatus of claim 17 wherein the sensor comprises a carbon dioxide sensor.

20. The apparatus of claim 17 wherein the sensor comprises a flow sensor.

21. The apparatus of claim 17 wherein the nasal tube comprises a nasopharyngeal catheter.

22. The apparatus of claim 17 wherein the nasal tube comprises a nasal cannula.