Respirator and method

• US 4,020,834 A
• Filed: 05/16/1975
• Issued: 05/03/1977
• Est. Priority Date: 05/16/1975
• Status: Expired due to Term

• Current Assignee: Forrest M. Bird
• Original Assignee: Forrest M. Bird
• Inventors: Bird, Forrest M.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/578,170
• Time in Patent Office: 718 Days
• Field of Search: 128/145.8, 128/145.6, 128/145.5, 128/146.5, 128/188
• 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 16/0075 Bellows-type
• CPC Class Codes: A61M 16/0081 Bag or bellow in a bottle
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/0825 with ball-sockets
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 2209/084 Supporting bases, stands for equipment

Abstract

A respirator with an inhalation phase and an exhalation phase in its operative cycle having an inlet adapted to be connected to a supply of gas under pressure and first and second outlets.

A device is provided for establishing a positive pressure above atmospheric against which the patient must exhale during the exhalation phase for a predetermined period near the end of the exhalation phase. A device is provided for terminating the application of positive pressure so that the patient is exposed to ambient atmospheric pressure prior to initiation of the inhalation phase. Inspiratory flow acceleration means is provided for supplying additional gases to the first outlet during the inhalation phase. A control device is provided for establishing the length of the inhalation phase and includes an auxiliary reservoir for collecting gas and means for bleeding off the gas from the auxiliary reservoir whereby the exhalation time can be adjusted without being adversely affected by the pressure of the inlet gas. A volume limiting device is provided so that when desired a precise volume of gas can be delivered to the patient. A device is provided for supplying an anesthesia gas in the gases supplied to the inlet so that the respirator can be utilized as an anesthesia unit.

Claims

1. In a respirator having an inhalation phase and an exhalation phase in its operative cycle, an inlet adapted to be connected to a source of gas under pressure, first and second outlets, a sequencing servo having an inlet connected to the inlet of the respirator, said sequencing servo also having an outlet, control valve means disposed in said sequencing servo and movable between open and closed positions to control the flow of gas from the inlet to the outlet of the sequencing servo, said control valve means being in an open or on position during the inhalation phase of the respirator and in a closed or off position during the exhalation phase of the respirator, a patient adapter, means for connecting the outlet of the sequencing servo to the first outlet of the respirator, means for supplying gas from the first outlet of the respirator to the patient adapter, an exhalation valve assembly connected to the patient adapter and movable between open and closed positions and in the open position permitting gases to flow from the patient adapter and in the closed position preventing the flow of gases from the patient adapter, means for supplying gas from the inlet of the respirator to the second outlet of the respirator, means for supplying gas from the second outlet of the respirator to the exhalation valve assembly to maintain the exhalation valve assembly in a closed position during the inhalation phase, means for sensing the pressure of the gas in the first outlet and for switching the sequencing servo from an open position to a closed position when a predetermined pressure is reached in the first outlet, means connected to the exhalation valve means for establishing a positive pressure against which the patient must exhale during the exhalation phase and means for terminating the application of positive pressure to the exhalation valve assembly near the end of the exhalation phase so that the patient is exposed to ambient pressure prior to initiation of the inhalation phase.

2. A ventilator as in claim 1 wherein said means for establishing a positive pressure against which the patient must exhale includes an expiratory flow gradient delay cartridge and means connecting said expiratory flow gradient cartridge to the exhalation valve assembly, said expiratory flow gradient delay cartridge delaying the application of the positive pressure until near the end of the exhalation phase.

3. A respirator as in claim 2 wherein said means for terminating the application of the positive pressure includes a positive end expiratory pressure termination cartridge which is connected to the expiratory flow gradient delay cartridge and to the exhalation valve assembly.

4. A respirator as in claim 1 together with means for establishing the period of time covered by the exhalation phase including an expiratory termination cartridge having valve means movable between open and closed positions, means connecting the expiratory termination cartridge to the inlet and to the sequencing servo whereby when the valve means of the expiratory termination cartridge is moved to an open position source gas is supplied to the sequencing servo, expiratory time control valve assembly connected to the expiratory termination cartridge for controlling the rate of bleed off of gas from the expiratory termination cartridge for controlling movement of the valve means of the expiratory termination cartridge from the closed to an open position, an auxiliary gas reservoir and adjustable orifice means connecting said auxiliary reservoir between said expiratory termination cartridge and said expiratory time control valve assembly.

5. A ventilator as in claim 1 together with means for supplying intermittent mandatory ventilation to the patient.

6. A respirator as in claim 5 wherein said means for supplying intermittent mandatory ventilation includes demand flow accelerator means having an inlet and an outlet and valve means controlling the flow of gases from the inlet to the outlet for supplying gases to the patient upon demand of the patient, means connecting the inlet of the demand flow accelerator means to the inlet of the respirator, means connecting the outlet of the demand flow accelerator to the first outlet of the respirator and means connecting the demand flow accelerator means to the patient breathing circuit for sensing the gases in the patient breathing circuit for moving the valve means of the demand flow accelerator means to permit flow of gases from the inlet to the outlet.

7. A respirator as in claim 6 wherein said means for sensing the pressure of the gases in the patient breathing circuit includes a sensing venturi and means connecting the sensing venturi to the sequencing servo.

8. A respirator as in claim 7 wherein said means for sensing the pressure of the gases in the patient breathing circuit includes means for monitoring the pressure in the breathing circuit independent of the sensing venturi.

9. A respirator as in claim 1 together with volume means for limiting the gases supplied to the patient by volume, said volume limiting means including a bellows assembly having a canister and a bellows disposed within the canister, piping means in communication with the interior of the bellows and in communication with the first outlet of the respirator, piping means in communication with the interior of the canister and in communication with the output from the sequencing servo, transfer valve means connected between the first and second named piping connected to the interior of the bellows and the piping connected to the interior of the canister and including a valve member movable between open and closed positions which in the open position permits flow between the first and second named piping means and in the closed position prevents flow between the first and second named piping means and forces flow from the second named piping means into the interior of the canister, said transfer valve means including means coupled to the output from the sequencing servo for moving the same to a closed position so that during an inhalation phase, inspiratory gases are supplied to the canister to raise the bellows and force gases contained in the bellows into the first outlet of the respirator and for transfering the gases in the canister to the interior of the bellows during the exhalation phase.

10. A respirator as in claim 9 together with means for adjustably limiting the travel of the bellows within the canister to limit the volume within the bellows so that only a predetermined quantity of gases are transferrred into the interior of the bellows.

11. A respirator as in claim 10 wherein said means for adjusting the travel of the bellows to determine the volume within the bellows includes a shaft coupled to the bellows, a cam member carried by the shaft and adjustable stop means adapted to be engaged by said cam member, said adjustable stop means being movable to limit the travel of the cam member and means for moving said stop member.

12. A respirator as in claim 11 wherein said means for moving the stop member includes a plurality of adjustable dial-like members, said dial like members being adjustable with respect to each other.

13. A respirator as in claim 12 wherein said dial-like members are mounted concentrically with respect to each other and means for locking said dial-like members in predetermined positions with respect to each other.

14. A respirator as in claim 11 together with counterweight means secured to the cam member for counterbalancing the bellows and the parts carried thereby.

15. A respirator as in claim 11 together with transfer switch means engagable by said cam member to cause operation of the transfer switch means and means connected to the inspiratory switch means for causing termination of the inhalation phase.

16. A respirator as in claim 1 together with gas accumulator means, selectively operated means for transfering gas from the accumulator means to the first outlet, and means for supplying gas to the accumulator means during the exhalation phase.

17. A respirator as in claim 9 wherein said bellows is removable from said canister together with quick release means for connecting said bellows to said shaft.

18. A respirator as in claim 11 together with gas balance valve means and means carried by said cam member for actuating said gas balance valve means and means connecting said gas balance means to the interior of said canister whereby in the event there is excess gas in the canister, the excess gas may be brought from the canister.

19. A respirator as in claim 11 together with gas refill means engagable by the cam member for introducing additional gas into the bellows when an insufficient quantity of gas is present in the bellows.

20. In a respirator having an inhalation phase and an exhalation phase in its operative cycle, an inlet adapted to be connected to a source of inspiratory gases under pressure, first and second outlets, a sequencing servo having an inlet, means connecting the inlet of the sequencing servo to the inlet of the respirator, said sequencing servo also having an outlet and control valve means movable between open and closed positions to control the flow of gas from the inlet to the outlet of the sequencing servo, said control valve means being in an open or on position during the inhalation phase of the respirator and in a closed or off position during exhalation phase of the respirator, a patient adapter, means for connecting the outlet of the sequencing servo to the first outlet of the respirator to supply inspiratory gases thereto, means for supplying gas from the first outlet of the respirator to the patient adapter, an exhalation valve assembly movable between open and closed positions and in the open position permitting gases to flow from the patient adapter and in the closed position preventing the flow of gases from the patient adapter, means for supplying gas from the inlet of the respirator to the second outlet of the respirator, means for supplying gas fom the second outlet of the respirator to the exhalation valve assembly to maintain the exhalation valve assembly in a closed position during the inhalation phase, volume limiting means for limiting the inspiratory gases supplied to the patient during the inhalation phase, said volume limiting means including a bellows assembly having a canister and a bellows disposed within the canister, first piping means in communcation with the interior of the bellows and in communication with the first outlet of the respirator, second piping means in communication with the interior of the canister and in communication with the outlet from the sequencing servo for supplying inspiratory gases from the inlet of the respirator to the interior of the canister, transfer valve means connected between the first piping means connected to the interior of the bellows and the second piping means connected to the interior of the canister and including a valve member movable between open and closed positions which in the open position permits flow between the first and second named piping means and forces flow from the second named piping means into the interior of the canister, said transfer valve means including means coupled to the output from the sequencing servo for moving the same to a closed position so that during the inhalation phase, inspiratory gases are supplied to the interior of the canister to raise the bellows and to thereby force inspiratory gases contained in the bellows into the first outlet of the respirator and through the patient adapter and for transferring gases in the canister to the interior of the bellows during the exhalation phase said first and second piping means in combination with said transfer valve means forming the sole means for establishing communication between the interior of the bellows and the interior of the canister.

21. A respirator as in claim 20 together with means for adjustably limiting the travel of the bellows within the canister so that only a predetermined quantity of gases are transferred into the interior of the bellows.

22. A respirator as in claim 21 wherein said means for adjusting the bellows to determine the volume of gases which can be transferred into the bellows includes an adjustable member for preventing movement of the bellows beyond a selected position and means for adjusting the position of said adjustable member.

23. A respirator as in claim 20 together with gas balance means and means engagable by operation of the bellows for eliminating excess gas from the bellows assembly.

24. A respirator as in claim 23 together with refill means engagable by movement of the bellows for introducing additional gas into the bellows assembly when an insufficient quantity of gas is present.

25. In a method for ventilating a patient through the use of a patient adapter from a source of gas under pressure, supplying a main flow of gas to the patient adapter during the inspiratory phase, permitting exhalation of gases from the patient adapter during the exhalation phase, establishing a positive pressure against which the patient must exhale during a portion of the exhalation phase and terminating the application of positive pressure in the exhalation phase near the end of the exhalation phase so that the patient is exposed to ambient pressure prior to initiation of the inhalation phase.

26. In a respirator having an inhalation phase and an exhalation phase in its operative cycle, an inlet adapted to be connected to a source of gas under pressure, first and second outlets, a sequencing servo having an inlet connected to the inlet of the respirator, said sequencing servo also having an outlet, control valve means disposed in said sequencing servo and movable between open and closed positions to control the flow of gas from the inlet to the outlet of the sequencing servo, said control valve means being in an open or on position during the inhalation phase of the respirator and in a closed or off position during the exhalation phase of the respirator, a patient adapter, means for connecting the outlet of the sequencing servo to the first outlet of the respirator, means for supplying gas from the first outlet of the respirator to the patient adapter, an exhalation valve assembly connected to the patient adapter and movable between open and closed positions and in the open position permitting gases to flow from the patient adapter and in the closed position preventing the flow of gases from the patient adapter, means for supplying gas from the inlet of the respirator to the second outlet of the respirator, means for supplying gas from the second outlet of the respirator to the exhalation valve assembly to maintain the exhalation valve assembly in a closed position during the inhalation phase, means for sensing the pressure of the gas in the first outlet and for switching the sequencing servo from an open position to a closed position when a predetermined pressure is reached in the first outlet, IMV demand flow means having an inlet and an outlet and valve means movable between open and closed positions for controlling the flow of gas between the inlet and the outlet of the IMV demand flow means, means connecting the inlet of the IMV demand flow means to the inlet of the respirator, means connecting the outlet of the IMV demand flow means to the first outlet of the respirator, means connecting the valve means of the IMV demand flow means to the patient breathing circuit whereby when the patient takes a breath a pressure drop will be sensed to cause movement of the valve means of the IMV demand flow means into a position to permit gas to flow from the inlet to the outlet of the IMV demand flow means and to the first outlet of the respirator, IMV assist means having an inlet and outlet and valve means movable between open and closed positions for controlling the flow of gas between the inlet and the outlet, means connecting the inlet of the IMV assist means to the inlet of the respirator, means connecting the outlet of the IMV assist means to the first outlet of the respirator, means connecting the valve means of the IMV assist means to the outlet of the IMV demand flow means whereby when gas passes from the inlet to the outlet of the IMV demand flow means, the valve means of the IMV assist means will be moved to a position to permit gas to flow from the inlet to the outlet of the IMV assist means to the first outlet of the respirator.

27. In a respirator as in claim 26 wherein means connecting the inlet of the IMV demand flow means includes on-off valve means for controlling the operation of said IMV demand flow means.

28. A respirator as in claim 27 wherein said means connecting IMV assist means to the inlet includes on-off valve means for controlling the operation of the IMV assist means.

29. In a respirator having an inhalation phase and an exhalation phase in its operative cycle, an inlet adapted to be connected to a source of gas under pressure, first and second outlets, a sequencing servo having an inlet connected to the inlet of the respirator, said sequencing servo also having an outlet, control valve means disposed in said sequencing servo and movable between open and closed positions to control the flow of gas from the inlet to the outlet of the sequencing servo, said control valve means being in an open or on position during the inhalation phase of the respirator and in a closed or off position during the exhalation phase of the respirator, a patient adapter, means for connecting the outlet of the sequencing servo to the first outlet of the respirator, means for supplying gas from the first outlet of the respirator to the patient adapter, an exhalation valve assembly connected to the patient adapter and movable between the open and closed positions and in the open position permitting gas to flow from the patient adapter and in the closed position preventing the flow of gases from the patient adapter, means for supplying gas from the inlet of the respirator to the second outlet of the respirator, means for supplying gas from the second outlet of the respirator to the exhalation valve assembly to maintain the exhalation valve assembly in a closed position during the inhalation phase, means for switching the control valve means of the sequencing servo from closed to open positions to determine the length of the inhalation and exhalation phases, said switching means including means for establishing the period time covered by the exhalation phase including expiratory termination means having an inlet and an outlet and valve means between open and closed positions, a diaphragm for controlling movement of the valve means and a chamber formed on one side of the diaphragm, means connecting the inlet of the expiratory termination means to the inlet of the respirator, means connecting the outlet of the expiratory termination means whereby the flow of gas through the expiratory termination means between the inlet and the outlet will cause movement of the control valve means of the sequencing servo from a closed to an open position, means for supplying gas under pressure the chamber to cause the diaphragm to move the valve means of the expiratory termination means from an open to a closed position to prevent the flow of gas from the inlet to the outlet of the expiratory termination means, means for bleeding off gas from the chamber of the expiratory termination means at a controlled rate to permit movement of the valve means of the expiratory termination means from a closed to an open position, said last-named means including valve means coupled to said chamber for adjusting the rate of the bleed-off of gas from said chamber, an auxiliary reservoir, one-way check valve means connecting the reservoir to said chamber to permit the flow of gas into the auxiliary reservoir and adjustable orifice means connecting the auxiliary reservoir to the valve means for bleeding air from the auxiliary.

30. In a respirator having an inhalation phase and an exhalation phase in its operative cycle, an inlet adapted to be connected to a source of gas under pressure, first and second outlets, a sequencing servo having an inlet adapted to be connected to the source of gas under pressure, first and second outlets, a sequencing servo having an inlet, means connecting the inlet of the sequencing servo to the inlet of the respirator, said sequencing servo also having an outlet and control valve means movable between open and closed positions to control the flow of gas from the inlet to the outlet of the sequencing servo, said control valve means being in an open or on position during the inhalation phase of the respirator and in a closed or off position during the exhalation phase of the respirator, a patient adapter, a patient adapter, means connecting the outlet of the sequencing servo to the first outlet of the respirator to the supply of gases thereto, means for supplying gas from the first outlet of the respirator to the patient adapter, an exhalation valve assembly movable between open and closed positions and in the open position permitting gas to flow from the patient adapter and in the closed position preventing the flow of gas from the patient adapter, means for supplying gas from the inlet of the respirator to the second outlet of the respirator, means for supplying gas from the second outlet of the respirator to the exhalation valve assembly to maintain the exhalation valve assembly in a closed position during the inhalation phase, volume limiting means for limiting the gas supply to the patient during the inhalation phase, said volume limiting means including a valve assembly having a canister and a bellows disposed within the canister, means for supplying gas from the inlet of the respirator to the interior of the canister, means for transferring gases from the interior of the canister to the interior of the bellows and means for adjustably limiting the travel of the bellows within the canister so that only a predetermined quantity of gases are transferred into the bellows, said means for adjustably limiting the travel including a movable stop adapted to limit travel of said bellows, a rotatable shaft, a flexible elongate member movable by rotation of said shaft to move said movable stop member a plurality concentrically mounted dial-like members carried by said shaft for rotating said shaft and being rotatably adjustable with respect to each other and means for locking said dial-like members in predetermined positions with respect to each other.

31. A respirator as in claim 30 together with gas balance valve means connected to the interior of the canister for discharging gas through the gas balance means when there is an excess of gas in the canister.

32. A respirator as in claim 30 together with counter-balance means for counterbalancing the bellows.