Pneumatically controlled multifunction medical ventilator

• US 6,591,835 B1
• Filed: 03/15/2000
• Issued: 07/15/2003
• Est. Priority Date: 09/26/1997
• Status: Expired due to Term

• Current Assignee: Airon Corporation
• Original Assignee: Airon Corporation
• Inventors: Blanch, Paul B.
• Primary Examiner(s): Lo, Weilun
• Assistant Examiner(s): PATEL, MITAL B
• Application Number:
  US09/508,706
• Time in Patent Office: 1,217 Days
• Field of Search: 128/204.26, 128/204.29, 128/205.11, 128/204.18, 128/204.21, 128/204.25, 128/204.22, 128/203.25, 128/204.24, 128/205.24
• US Class Current: 128/204.25
• 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 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/127 by Venturi effect, i.e. entrainment mixers

Abstract

A multiple functionality pneumatically controlled medical ventilator provides precision regulation of tidal/forced breathing, and continuous positive airway pressure (CPAP)-based spontaneous breathing capability. The ventilator includes a patient breathing gas coupler that is adapted to be coupled to a patient airway breathing interface, and an input port to which a pressurized breathing gas is coupled, A pressure regulator supplies breathing gas at a positive pressure sufficiently higher than nominal lung pressure to prevent collapse of the patient'"'"'s lungs. A tidal breathing gas supply unit periodically generates a volume-regulated tidal breathing gas for application to the patient airway breathing interface, while the CPAP valve supplies a pressure-regulated breathing gas to the patient airway breathing interface, in response to a patient demand for breathing gas that is exclusive of the tidal breathing supply.

Claims

1. A pneumatically controlled medical ventilator apparatus comprising:

a patient air supply output coupler that is configured to be coupled to a patient airway breathing interface;

a breathing gas input port to which a pressurized supply of breathing gas is coupled;

a tidal breathing gas supply unit coupled to said breathing gas input port, and being operative to periodically supply a controllable concentration of regulated volume tidal breathing gas for application to said patient airway breathing interface; and

a continuous positive airway pressure (CPAP) valve including a valve input port and a patient demand monitoring port, the valve input port being coupled to the breathing gas input port, and said CPAP valve being operative to supply regulated pressure breathing gas to said patient air supply output coupler, in response to a patient initiating a breath;

said patient air supply output coupler including a venturi unit and an on-demand breath monitoring port connected to the patient demand monitoring port of said CPAP valve, the venturi unit also being coupled to a source of ambient air, and being operative to supply said regulated pressure breathing gas as a mixture of ambient air and said pressurized breathing gas.

2. A pneumatically controlled medical ventilator apparatus according to claim 1, wherein said CPAP valve has a control port coupled to said patient air supply output coupler, and being operative to supply said regulated pressure breathing gas in response to a prescribed change in pressure of said control port.

3. A pneumatically controlled medical ventilator apparatus according to claim 1, wherein said tidal breathing gas supply unit is operative to periodically supply a controllable concentration of tidal breathing gas to said patient air supply output coupler.

4. A pneumatically controlled medical ventilator apparatus according to claim 3, wherein said tidal breathing gas supply unit includes a venturi unit coupled to a source of ambient air and to a periodically supplied quantity of regulated pressure breathing gas, and being operative to supply said controllable concentration of regulated pressure breathing gas as a mixture of ambient air and said regulated pressure breathing gas to said patient air supply output coupler.

5. A pneumatically controlled medical ventilator apparatus according to claim 1, wherein said tidal breathing gas supply unit is configured to periodically supply a first concentration of tidal breathing gas to said patient airway breathing interface.

6. A pneumatically controlled medical ventilator apparatus according to claim 5, wherein said tidal breathing gas supply unit is configured to periodically supply a second concentration of tidal breathing gas to said patient air supply output coupler.

7. A pneumatically controlled medical ventilator apparatus according to claim 1, wherein said patient airway breathing interface includes an exhalation valve, and wherein each of said tidal breathing gas supply unit and said CPAP valve is coupled to provide a regulated pressure for controlling the operation of said exhalation valve.

8. A pneumatically controlled medical ventilator apparatus according to claim 1, wherein said tidal breathing gas supply unit comprises a pneumatic timing unit and a tidal breathing control switch, said pneumatic timing unit being operative to supply a periodic pneumatic control signal associated with a prescribed supply of tidal breathing gas to the tidal breathing control switch, said tidal breathing control switch being operative to controllably couple pressure-regulated breathing gas to said patient airway breathing interface.

9. A pneumatically controlled medical ventilator apparatus according to claim 8, wherein said pneumatic timing unit includes a pneumatic timing device and a pneumatic time constant circuit coupled therewith for controlling charging and bleeding of pressurized gas with respect to said pneumatic timing device, and thereby defining a tidal breathing rate and a duty cycle of a respective tidal breath interval of a periodically supplied controllable concentration of regulated volume tidal breathing gas applied to said patient airway breathing interface.

10. A pneumatically controlled medical ventilator apparatus comprising a patient breathing gas output adapted to be coupled to a patient airway breathing interface applied to a patient, a breathing gas input port to which a pressurized breathing gas is coupled, a gas pressure regulator coupled to said breathing gas input port, and being operative to supply said breathing gas at a prescribed positive pressure higher than the nominal lung pressure of said patient, that is effective to prevent collapse of the patient'"'"'s lungs, a tidal breathing gas supply unit coupled to said gas pressure regulator, and being operative to periodically generate a volume-regulated tidal breathing gas for application to said patient airway breathing interface, and a continuous positive airway pressure (CPAP) valve including a valve input port and a patient demand monitoring port, the valve input port being coupled to the breathing gas input port, and said CPAP valve being operative to supply pressure-regulated breathing gas to said patient breathing gas output in response to a patient demand for breathing gas, said patient breathing gas output including a venturi unit and an on-demand breath monitoring port connected to the patient demand monitoring port of said CPAP valve, the venturi unit also being coupled to a source of ambient air, and is operative to supply said regulated pressure breathing gas as a mixture of said ambient air and said pressurized breathing gas in response to a prescribed change in pressure of said patient demand monitoring port.

11. A pneumatically controlled medical ventilator apparatus according to claim 10, wherein said tidal breathing gas supply unit is operative to periodically supply a first concentration of tidal breathing gas to said patient airway breathing interface, and a reduced concentration of tidal breathing gas to said patient breathing gas output.

12. A pneumatically controlled medical ventilator apparatus according to claim 11, wherein said tidal breathing gas supply unit includes a venturi unit coupled to a source of ambient air and to a periodically supplied quantity of pressure-regulated breathing gas, and being operative to supply said reduced controllable concentration of breathing gas as a mixture of said ambient air and said pressure-regulated breathing gas to said patient breathing gas output.

13. A pneumatically controlled medical ventilator apparatus according to claim 10, wherein said patient airway breathing interface includes an exhalation valve, and wherein each of said tidal breathing gas supply unit and said CPAP valve is coupled to provide a regulated pressure for controlling the operation of said exhalation valve.

14. A pneumatically controlled medical ventilator apparatus according to claim 10, wherein said tidal breathing gas supply unit comprises a pneumatic timing unit and a tidal breathing control switch, said pneumatic timing unit being operative to supply a periodic pneumatic control signal associated with a prescribed supply of tidal breathing gas to the tidal breathing control switch, said tidal breathing control switch being operative to controllably couple pressure-regulated breathing gas to said patient airway breathing interface.

15. A method of providing a patient breathing gas to a patient airway breathing interface of a patient, comprising the steps of:

(a) periodically pneumatically supplying a regulated pressure breathing gas, at a positive pressure higher than the nominal lung pressure of said patient and effective to prevent collapse of the patient'"'"'s lungs, to said patient airway breathing interface; and

(b) in response to a pneumatically based patient demand for breathing gas, and exclusive of said periodic pneumatic supply of a tidal breathing gas in step (a), pneumatically supplying a continuous positive airway pressure (CPAP) breathing gas to said patient airway breathing interface through a venturi unit as a mixture of ambient air and pressurized breathing gas.

16. A method according to claim 15, wherein step (a) comprises selectively periodically supplying one of a first concentration of tidal breathing gas to said patient airway breathing interface, and a second, reduced concentration of tidal breathing gas to said patient airway breathing interface.

17. A method according to claim 15, wherein said patient airway breathing interface includes an exhalation valve, and wherein each of steps (a) and (b) comprises providing a regulated pressure for controlling the operation of said exhalation valve.