Intermittent gas-insufflation apparatus

• US 5,697,364 A
• Filed: 06/07/1995
• Issued: 12/16/1997
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Salter Labs
• Original Assignee: Salter Labs
• Inventors: Chua, James, Salter, Peter W., Wada, Robert Toshiaki, Kelly, Francis J., Fujimoto, Roy Yasuo
• Primary Examiner(s): Millin, Vincent
• Assistant Examiner(s): SRIVASTAVA, VIRENDRA KUMAR
• Application Number:
  US08/480,353
• Time in Patent Office: 923 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.22, 128/204.23, 128/205.24, 128/203.12, 128/207.14, 128/207.18
• US Class Current: 128/204.21
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0677 Gas-saving devices therefor
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor

Abstract

An intermittent gas-insufflation apparatus insufflates a quantity of the gaseous fluid into an entrance of a respiratory system of a breathing patient during an exhalation interval of an immediate breathing cycle and into a subsequent inhalation interval of a successive breathing cycle. The intermittent gas-insufflation apparatus includes a valve assembly, a sensor and a controller. The valve assembly actuates between a closed state to prevent the gaseous fluid from flowing from a source of gaseous fluid to the patient and an opened state to establish gaseous fluid flow to the patient. The sensor detects changes in breathing pressure of the patient throughout the immediate breathing cycle and to generates sensor signals characteristic of the changes in the breathing pressure thereof. The controller receives and processes the sensor signals during either the inhalation interval of the immediate breathing cycle, the exhalation interval of the immediate breathing cycle or both and is responsive within the exhalation interval of the immediate breathing cycle to the sensor signals to actuate the valve assembly into the opened state so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient during the exhalation interval of the immediate breathing cycle and into the subsequent inhalation interval of the successive breathing cycle. Methods are also described for various exemplary embodiments of the present invention and for maintenance of blood-oxygen concentration for a patient receiving oxygen from a supplemental oxygen delivery system.

Claims

1. An intermittent gas-insufflation apparatus adapted to be disposed between and in fluid communication with a source of pressurized gaseous fluid and a breathing patient and operative to insufflate a quantity of the gaseous fluid into an entrance of a respiratory system of the patient after an inhalation interval and during an exhalation interval of an immediate breathing cycle and into a subsequent inhalation interval of a successive breathing cycle of the patient, comprising:

(a) a valve assembly adapted to be disposed between and in fluid communication with the source of gaseous fluid and the entrance into the respiratory system of the patient and operative to actuate between a closed state whereby fluid communication is interrupted so that the gaseous fluid is prevented from flowing from the source of gaseous fluid to the entrance into the respiratory system of the patient and an opened state whereby fluid communication is established so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient;

(b) a pressure transducer sensor in fluid communication with the entrance of the respiratory system of the breathing patient and operative to detect changes in breathing pressure of the breathing patient relative to an ambient pressure environment throughout the inhalation and exhalation intervals of the immediate breathing cycle of the patient and to generate sensor signals characteristic of the changes in the breathing pressure of the immediate breathing cycle; and

(c) a microprocessor controller coupled to and between said sensor and said valve assembly and operative to receive and process the sensor signals to determine

a negative peak pressure value which occurs during the inhalation interval of the immediate breathing cycle and

a positive peak pressure value which occurs during the exhalation interval of the immediate breathing cycle,

said controller responsive within the exhalation interval of the immediate breathing cycle when a first predetermined percentage of the positive peak pressure value is achieved to actuate said valve assembly into the opened state so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient during the exhalation interval of the immediate breathing cycle and into the subsequent inhalation interval of the successive breathing cycle,

said controller further responsive within the subsequent inhalation interval of the successive breathing cycle when a third predetermined percentage of the negative peak pressure value is achieved to further actuate said valve assembly into an enhanced opened state so that an additional quantity of gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient after the exhalation interval of the immediate breathing cycle and before a remaining portion of the subsequent inhalation interval of the successive breathing cycle, and

said controller further responsive within the subsequent inhalation interval of the successive breathing cycle when a second predetermined percentage of the negative peak pressure value is achieved to actuate said valve assembly into the closed state so that the gaseous fluid is prevented from flowing from the source of gaseous fluid to the entrance into the respiratory system of the patient.

2. An intermittent gas-insufflation apparatus according to claim 1 including a power source operative to energize said sensor, said controller and said valve assembly.

3. An intermittent gas-insufflation apparatus according to claim 2 wherein said power source includes a battery.

4. An intermittent gas-insufflation apparatus according to claim 3 wherein said power source includes an AC/DC converter for receiving and converting alternating current into direct current.

5. An intermittent gas-insufflation apparatus according to claim 4 whereby said direct current is operative to trickle charge said battery.

6. An intermittent gas-insufflation apparatus according to claim 1 wherein said third predetermined percentage is selected from a range of 1% and 25% inclusive and is less than said second predetermined percentage.

7. An intermittent gas-insufflation apparatus according to claim 1 wherein said valve assembly includes a first solenoid valve operative between a first closed state and a first opened state and a second solenoid valve operative between a second closed state and a second opened state, each of said first and second solenoid valves being independently connected in fluid communication to and between the source of pressurized gas and the entrance into the respiratory system of the patient and being independently connected electrically to said controller.

8. An intermittent gas-insufflation apparatus according to claim 7 wherein said first solenoid valve is operative to actuate from the first closed state to the first opened state during the exhalation interval of the immediate breathing cycle and from the first opened state to the first closed state at a later stage of the subsequent inhalation interval of the successive breathing cycle while said second solenoid valve is operative to actuate from the second closed state to the second opened state at approximately a beginning stage of the subsequent inhalation interval of the successive breathing cycle thereby causing the enhanced opened state of said valve assembly and from the second opened state to the second closed state at the later stage of the subsequent inhalation interval of the successive breathing cycle.

9. An intermittent gas-insufflation apparatus according to claim 8 wherein said first solenoid valve and said second solenoid valve respectively actuates to the first closed state and the second closed state when said second predetermined percentage of the negative peak pressure value is achieved.

10. An intermittent gas-insufflation apparatus according to claim 8 wherein the gaseous fluid flows in a steady-state flow stream when said first solenoid valve is in the first opened state and the gaseous fluid flows in a high flow-rate pulse when said second solenoid valve is in the second opened state.

11. An intermittent gas-insufflation apparatus according to claim 1 wherein said first and second predetermined percentages are one of being different from one another and being the same.

12. An intermittent gas-insufflation apparatus according to claim 11 wherein each of said first and second predetermined percentages is selected from a range 10% and 80% inclusive.

13. An intermittent gas-insufflation apparatus according to claim 1 wherein said gaseous fluid flows at a flow rate selected from a flow rate range between 0.5 liters per minute and 12 liters per minute inclusive.

14. An intermittent gas-insufflation apparatus according to claim 1 further including a nasal cannula, a gas delivery tube and a sensing tube, said nasal cannula sized and adapted to be received by and secured proximate to the entrance of the respiratory system of the breathing patient, said nasal cannula having a septum dividing said nasal cannula into a gas delivery conduit and a sensing conduit isolated from fluid communication with one another, said gas delivery conduit in fluid communication with said valve assembly and said sensing conduit in fluid communication with said sensor.

15. An intermittent gas-insufflation apparatus according to claim 1 wherein said valve assembly is selected from a group consisting of a solenoid valve, a stepped solenoid valve, a proportional valve, a shape-memory alloy-film actuated valve, an arrangement of solenoid valves, an arrangement of stepped solenoid valves, an arrangement of proportional valves and an arrangement of shape-memory alloy-film actuated valves.

16. An intermittent gas-insufflation apparatus according to claim 1 wherein said first and second predetermined percentages are tailored to respiratory needs of each individual patient.

17. An intermittent gas-insufflation apparatus according to claim 16 wherein said third predetermined percentage is tailored to respiratory needs of each individual patient.

18. An intermittent gas-insufflation apparatus according to claim i wherein the gaseous fluid is selected from a group consisting of oxygen, air, nitrous oxide and ether.

19. An intermittent gas-insufflation apparatus adapted to be disposed between and in fluid communication with a source of pressurized gaseous fluid and a breathing patient and operative to insufflate a quantity of the gaseous fluid into an entrance of a respiratory system of the patient after an inhalation interval and during an exhalation interval of an immediate breathing cycle and into a subsequent inhalation interval of a successive breathing cycle of the patient, comprising:

(a) a valve assembly adapted to be disposed between and in fluid communication with the source of gaseous fluid and the entrance into the respiratory system of the patient and operative to actuate between a closed state whereby fluid communication is interrupted so that the gaseous fluid is prevented from flowing from the source of gaseous fluid to the entrance into the respiratory system of the patient and an opened state whereby fluid communication is established so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient;

(b) a pressure transducer sensor in fluid communication with the entrance of the respiratory system of the breathing patient and operative to detect changes in breathing pressure of the breathing patient relative to an ambient pressure environment throughout the inhalation and exhalation intervals of the immediate breathing cycle of the patient and to generate sensor signals characteristic of the changes in the breathing pressure of the immediate breathing cycle; and

(c) a microprocessor controller coupled to and between said sensor and said valve assembly and operative to receive and process the sensor signals generated by said sensor during the immediate breathing cycle to calculate how much of the quantity of the gaseous fluid is required by the breathing effort of the patient, said controller responsive to the sensor signals to actuate said valve assembly into the opened state so that the calculated quantity of gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient during the exhalation interval of the immediate breathing cycle and into the subsequent inhalation interval of the successive breathing cycle, said controller further responsive to actuate said valve assembly into the closed state during the subsequent inhalation interval of the successive breathing cycle when the calculated quantity of gaseous fluid is delivered to the entrance into the respiratory system of the patient.

20. An intermittent gas-insufflation apparatus according to claim 19 wherein said controller is further operative to determine a flow rate profile of the calculated quantity of the gaseous fluid for continuous flow thereof into the entrance into the respiratory system of the breathing patient during the exhalation interval of the immediate breathing cycle and the subsequent inhalation interval of the successive breathing cycle.

21. An intermittent gas-insufflation apparatus according to claim 20 wherein said flow rate profile is selected from a group consisting of a constant flow rate profile, a variable flow rate profile and a combination fixed and variable flow rate profile.

22. An intermittent gas-insufflation apparatus according to claim 21 wherein a maximum flow rate of the calculated quantity of gaseous fluid flowing into the entrance of the respiratory system of the breathing patient during the exhalation interval of the immediate breathing cycle occurs after a beginning stage of the inhalation interval of the subsequent breathing cycle.

23. An intermittent gas-insufflation apparatus according to claim 20 wherein said flow rate profile of the gaseous fluid includes a flow rate range having a minimum flow rate of 0.5 liters per minute and a maximum flow rate of 12.0 liters per minute.

24. An intermittent gas-insufflation apparatus according to claim 19 wherein said valve assembly is selected from a group consisting of a solenoid valve, a stepped solenoid valve, a proportional valve, a shape-memory alloy-film actuated valve, an arrangement of solenoid valves, an arrangement of stepped solenoid valves, an arrangement of proportional valves and an arrangement of shape-memory alloy-film actuated valves.

25. An intermittent gas-insufflation apparatus adapted to be disposed between and in fluid communication with a source of pressurized gaseous fluid and a breathing patient and operative to insufflate a quantity of the gaseous fluid into an entrance of a respiratory system of the patient after an inhalation interval and during an exhalation interval of an immediate breathing cycle and into a subsequent inhalation interval of a successive breathing cycle of the patient, comprising:

(a) a valve assembly adapted to be disposed between and in fluid communication with the source of gaseous fluid and the entrance into the respiratory system of the patient and operative to actuate between a closed state whereby fluid communication is interrupted so that the gaseous fluid is prevented from flowing from the source of gaseous fluid to the entrance into the respiratory system of the patient and an opened state whereby fluid communication is established so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient;

(b) a pressure transducer sensor in fluid communication with the entrance of the respiratory system of the breathing patient and operative to detect changes in breathing pressure of the breathing patient relative to an ambient pressure environment throughout the inhalation and exhalation intervals of the immediate breathing cycle of the patient and to generate sensor signals characteristic of the changes in the breathing pressure of the immediate breathing cycle; and

(c) a microprocessor controller coupled to and between said sensor and said valve assembly and operative to receive and process the sensor signals generated during one of the inhalation interval of the immediate breathing cycle, the exhalation interval of the immediate breathing cycle and the inhalation and exhalation intervals of the immediate breathing cycle, said controller responsive within the exhalation interval of the immediate breathing cycle to said sensor signals to actuate said valve assembly into the opened state so that the gaseous fluid flows from the source of gaseous fluid to the entrance into the respiratory system of the patient during the exhalation interval of the immediate breathing cycle and into the subsequent inhalation interval of the successive breathing cycle.

26. An intermittent gas-insufflation apparatus according to claim 25 wherein said valve assembly actuates into the opened state at a waning stage of the exhalation interval of the immediate breathing cycle.

27. An intermittent gas-insufflation apparatus according to claim 25 wherein said valve assembly actuates into the closed state during a later stage of the subsequent inhalation interval of the successive breathing cycle.