AUTOMATIC THERAPEUTIC VENTILATOR

• US 3,789,837 A
• Filed: 12/11/1970
• Issued: 02/05/1974
• Est. Priority Date: 12/11/1970
• Status: Expired due to Term

• Current Assignee: Jack Anthony Liddall, Walter John Philips
• Original Assignee: Jack Anthony Liddall, Walter John Philips
• Inventors: Philips, Walter John, Liddall, Jack Anthony
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Dunne, G. F.
• Application Number:
  US05/097,279
• Time in Patent Office: 1,152 Days
• Field of Search: 128/145.6,145.8,188,145.5 137/566,624.14,624.15
• US Class Current: 128/202.22
• 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 16/0075 Bellows-type
• CPC Class Codes: A61M 16/0081 Bag or bellow in a bottle
• CPC Class Codes: A61M 16/022 Control means therefor
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/186 Locking systems
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 16/206 Capsule valves, e.g. mushroom, membrane valves
• CPC Class Codes: Y10T 137/86163 Parallel

Abstract

An automatic therapeutic ventilator having an oxygen bellows for receiving and measuring a volume of oxygen and a breathing mixture bellows for mixing the oxygen with air in a predetermined ratio. Pneumatic and electrical control circuits are provided for automatic, semi-automatic, and patient-triggered modes, and a sigh circuit is incorporated in the control circuits. The bellows are mounted on trays which can be replaced simply.

Claims

1. A therapeutic ventilator adapted to be connected to a patient adaptor means operable to convey a breathing mixture to a patient, said ventilator comprising:

support means;

an oxygen bellows coupled to the support means for receiving a predetermined volume of oxygen under pressure during an inhalation period;

a breathing mixture bellows coupled to the support means and to the oxygen bellows for receiving said volume of oxygen during an exhalation period;

air valve means operable to permit air to enter the breathing mixture bellows contemporaneously with the oxygen so that said air and oxygen are mixed in a predetermined volumetric ratio thereby creating a breathing mixture;

oxygen control valve means operably coupled to the oxygen bellows to permit said pressurized oxygen to flow into the oxygen bellows during an inhalation period until the oxygen bellows contains said predetermined volume, and to permit said volume of oxygen to flow from said oxygen bellows into said breathing mixture bellows during said exhalation period; and

control means coupled to said oxygen control valve means and operable to open said breathing mixture bellows during said exhalation period whereby said predetermined volume of oxygen and air are drawn into said breathing mixture bellows until a predetermined volume of breathing mixture is contained in the breathing mixture bellows such that the air and oxygen are in said predetermined ratio and also operable to collapse said breathing mixture bellows during said inhalation period whereby substantially all of said predetermined volume of breathing mixture is forced through said patient adaptor means into a patient'"'"''"'"'s lungs.

2. A therapeutic ventilator as claimed in claim 1 in which said oxygen control valve means comprises:

a flap valve operable automatically to open under the force of the pressurized oxygen to permit the oxygen to flow into the oxygen bellows during the inhalation period, and to close upon removing the oxygen pressure from the valve means thereby preventing return flow of oxygen out of the oxygen bellows.

3. A therapeutic ventilator as claimed in claim 1 in which said oxygen control valve means comprises a valve seat and a diaphragm, said diaphragm having a flexible portion for engaging against said valve seat under the influence of the pressurized oxygen to prevent flow of oxygen from said oxygen bellows into said breathing mixture bellows during the inhalation period, and said flexible portion moving off said valve seat upon removing the oxygen pressure from the valve means so that oxygen flows from the oxygen bellows into the breathing mixture bellows during the exhalation period.

4. A therapeutic ventilator as claimed in claim 1 and further comprising an adjustable flow valve operable to control the rate of flow of pressurized oxygen into said oxygen bellows during said inhalation period so that said predetermined volume of oxygen may be varied according to the volume of oxygen required to prepare said predetermined volume of breathing mixture.

5. A therapeutic ventilator as claimed in claim 1 and further comprising:

an oxygen weight coupled to said oxygen bellows for collapsing said bellows so that the oxygen bellows is normally in a collapsed condition; and

a breathing mixture weight coupled to the breathing mixture bellows for opening the breathing mixture bellows so that the breathing mixture bellows is normally in a fully opened position.

6. A therapeutic ventilator as claimed in claim 1 wherein said control means comprises:

a casing containing the breathing mixture bellows; and

valve means operable to permit compressed air and the like to enter the casing about the breathing mixture bellows for collapsing the bellows during the inhalation period.

7. A therapeutic ventilator as claimed in claim 6 in which the control means further comprises:

an adjustable flow valve operable to permit compressed air to collapse the breathing mixture bellows during the inhalation period until said predetermined volume of breathing mixture has been forced out of the breathing mixture bellows.

8. A therapeutic ventilator as claimed in claim 7 and further comprising an adjustable flow valve operable control the rate of flow of pressurized oxygen into said oxygen bellows during said inhalation period so that said volume of oxygen may be varied as required to prepare said predetermined volume of breathing mixture.

9. A therapeutic ventilator as claimed in claim 8 and further comprising an oxygen supply valve operable to cut off the supply of pressurized oxygen during the exhalation period;

and a compressed air supply valve operable to cut off the supply of compressed air during the exhalation period, the supply valves being ganged to operate in unison.

10. A therapeutic ventilator as claimed in claim 9 and further comprising electrical control means;

and wherein the oxygen and compressed air supply valves are solenoid operated, the supply valves being electrically coupled to the electrical control means for closing the supply valves during the exhalation period.

11. A therapeutic ventilator as claimed in claim 10 in which the electrical control means comprises:

an inhalation timer having a first potentiometer variable for adjusting the inhalation period; and

an exhalation timer having second and third potentiometers in series and variable for selectively adjusting the exhalation period, the first and second potentiometers being ganged to operate in unison and having substantially similar effects upon respective inhalation and exhalation timers such that with the third potentiometer set at zero resistance the inhalation and exhalatioN periods are substantially equal for all positions of the first and second potentiometers and such that introduction of the third potentiometer resistance increases the exhalation period whereby the exhalation period is never shorter than the inhalation period.

12. A therapeutic ventilator as claimed in claim 1 in which the control means comprises a casing about the breathing mixture bellows for receiving compressed air to collapse the bellows.

13. A therapeutic ventilator as claimed in claim 12 and further comprising:

an electrical control circuit including a cycle timer circuit;

a solenoid operated oxygen supply valve operable to cut off the supply of oxygen during the exhalation period; and

a solenoid operated compressed air supply valve operable to cut off the supply of compressed air to the casing during the exhalation period, the solenoid operated valves being coupled electrically to the cycle timer circuit for contemporaneous operation.

14. A therapeutic ventilator as claimed in claim 12 and further comprising:

an oxygen supply valve operable to cut off the supply of oxygen during the exhalation period;

a compressed air supply valve operable to cut off the supply of compressed air during the exhalation period; and

control means operable to maintain the supply valves open during the inhalation period and to maintain the supply valves closed during the exhalation period.

15. A therapeutic ventilator as claimed in claim 12 and further comprising:

an adjustable flow valve operable to control the rate of flow of pressurized oxygen into said oxygen bellows during said inhalation period so that said volume of oxygen may be varied as required to prepare said predetermined volume of breathing mixture and in which the control means further comprises;

an adjustable flow valve operable to permit compressed air to collapse the breathing mixture bellows during the inhalation period until said predetermined volume of breathing mixture has been forced out of the breathing mixture bellows.

16. A therapeutic ventilator as claimed in claim 1 and further comprising means providing a sigh periodically and including means operable to adjust the period between sighs, said sigh means being coupled to said control means to further collapse said breathing mixture bellows without increasing said inhalation so that the patient receives a greater volume of breathing mixture during a sigh inhalation.

17. A therapeutic ventilator as claimed in claim 1 and further comprising means providing a sigh periodically and including means operable to adjust the period of the sigh, said sigh means being coupled to the control means to lengthen an inhalation period so that the patient receives a greater volume of breathing mixture during a sigh inhalation.

18. A therapeutic ventilator as claimed in claim 13 in which the electrical control circuit further comprises a sigh control circuit and a sigh bypass pipe having a solenoid operated sigh supply valve, the bypass pipe extending about said compressed air supply valve so that with the sigh supply valve and the compressed air supply valve open the flow of compressed air to the casing is increased during the inhalation period, said sigh control circuit including adjustable timer means for setting the period of the sigh and for operating said sigh supply valve contemporaneously with said compressed air supply valve once every sigh period, the sigh period being substantially greater than the sum of the inhalation and exhalation periods.

19. A therapeutic ventilator as claimed in claim 13 in which the electrical control circuit further comprises a sigh control circuit coupled to the cycle timer circuit and adapted to periodically increase the inhalation period, the sigh control circuit being adjustable for varying the sigh period and for varying the time by which the inhalation period is increased so that the patient receives an increased volume of breathing mixture during a sigh inhalation and the oxygen bellows receives a proportioNately larger volume of oxygen whereby the percentage volume of oxygen in the breathing mixture remains substantially constant.

20. A therapeutic ventilator as claimed in claim 18 and further comprising:

an oxygen flow valve operable to adjustably set the rate of flow of oxygen through the oxygen supply valve;

a compressed air flow valve operable to adjustably set the rate of flow of compressed air through the compressed air supply valve; and

a sigh flow valve operable to adjustably set the rate of flow of compressed air through the sigh supply valve.

21. A therapeutic ventilator as claimed in claim 19 and further comprising flow valves operable to adjustably set the rate of flow of oxygen through the oxygen supply valve, and operable to adjustably set the rate of flow of compressed air through the compressed air supply valve.

22. A therapeutic ventilator as claimed in claim 1 and further comprising:

a humidifier coupled to the breathing mixture bellows for receiving breathing mixture and adapted to add moisture to the breathing mixture during the inhalation period.

23. A therapeutic ventilator as claimed in claim 1 and further comprising a breathing control valve assembly operable to permit breathing mixture to be forced to the patient during the inhalation period and to permit exhaled breath to flow from the patient to an outlet during the exhalation period, the breathing control valve assembly comprising:

a flap valve operable automatically to open under the force of the breathing mixture to permit the breathing mixture to flow to the patient, and to close after the inhalation period thereby preventing return flow of exhaled breath from the patient into the breathing mixture bellows;

a valve seat;

a diaphragm having a flexible portion for engaging against the valve seat to prevent flow of breathing mixture into said outlet; and

a control pipe coupling the breathing control valve to said supply of compressed air for forcing said flexible portion onto said valve seat during said inhalation period.

24. A therapeutic ventilator as claimed in claim 23 and further comprising an orifice assembly coupled to said control pipe for bleeding off compressed air from said control pipe after said inhalation period so that the pressure in said control pipe drops and said flexible portion moves off said valve seat to permit exhaled breath to leave through said outlet during the exhalation period, said orifice assembly being adjustable so that the rate of bleeding can be varied to ensure that the flexible portion moves away from the valve seat such that the patient'"'"''"'"'s lungs are full of breathing mixture for an adjustable fraction of the exhalation period.

25. A therapeutic ventilator as claimed in claim 1 and further comprising:

a spirometer adapted to receive exhaled breath during the exhalation period and including a poppet valve operable to permit the exhaled breath to be vented from the spirometer during the inhalation period; and

a control pipe coupling the poppet valve to the compressed air supply for opening the poppet valve during the inhalation period.

26. A therapeutic ventilator as claimed in claim 12 and further comprising an electrical control circuit adapted to shut off the flow of oxygen and compressed air contemporaneously during the exhalation period, the electrical control circuit including a pressure control circuit adapted to respond to a low pressure created by the patient'"'"''"'"'s efforts to breathe whereby an inhalation period begins and adapted to respond to a selected high pressure when the patient'"'"''"'"'s lungs are full of breathing mixture whereby an exhalation period begins.

27. A therapeutic ventilator as claimed in claim 12 and further comprising an electrical control circuit adapted to shut off the flow of oxygen and compressed air contemporaneously during the exhalation period, the electrical control circuit including a pressure control circuit and a cycle timer circuit, the cycle timer circuit automatically controlling the timing of tHe inhalation and exhalation periods unless the patient attempts to inhale before the completion of an exhalation period, said pressure control circuit being adapted to respond to a reduced pressure created by the patient'"'"''"'"'s attempt to inhale whereupon an inhalation period is commenced and the cycle timer begins to time a new inhalation and exhalation sequence.

28. A therapeutic ventilator as claimed in claim 27 and further comprising a low pressure alarm adapted to operate should the pressure in a tube feeding breathing mixture to the patient fall below a minimum pressure for a period longer than about two complete breathing cycles.

29. A therapeutic ventilator for forcing a breathing mixture into a patient'"'"''"'"'s lungs during an inhalation period and for permitting the patient to expel exhaled breath during an exhalation period, the ventilator comprising:

a pair of end members defining first and second pairs of spaced-apart and parallel grooves, each pair of grooves extending longitudinally of the ventilator;

a breathing mixture tray slidable in said first pair of grooves;

a breathing mixture bellows releasably coupled to said tray;

a connecting conduit coupled to said tray and adapted to receive breathing mixture from the bellows and having a connecting end remote from the bellows;

a humidifier tray slidable in said second pair of grooves;

a humidifier coupled to said humidifier tray;

a humidifier conduit coupled to the humidifier tray and adapted to receive breathing mixture from the connecting conduit and to direct said breathing mixture into the humidifier; and

a coupling means attached to an end of said humidifier conduit remote from said humidifier and adapted to slidably receive said connecting end of the connecting conduit whereby the connecting conduit is pneumatically sealed to the humidifier conduit, said conduits being positioned on respective trays such that upon sliding the trays toward one another in the respective pairs of grooves, said connecting end engages in the coupling means.

30. A therapeutic ventilator for forcing a breathing mixture into a patient'"'"''"'"'s lungs during an inhalation period and for permitting the patient to expel exhaled breath during an exhalation period, the ventilator comprising:

a pair of end members defining first and second pairs of spaced-apart and parallel grooves, the second pair of grooves being above the first pair and parallel therewith;

a breathing mixture tray slidable in said first pair of grooves;

a breathing mixture bellows releasably coupled to said tray;

an oxygen output conduit coupled to said tray and adapted to receive oxygen from the bellows and having a connecting end remote from the bellows;

an oxygen tray slidable in said second pair of grooves;

an oxygen bellows releasably coupled to the oxygen tray;

an intermediate oxygen conduit coupled to the oxygen tray and adapted to carry oxygen to and from the oxygen bellows, the intermediate oxygen conduit having a connecting end remote from the oxygen bellows;

an oxygen control valve assembly coupled to the end members and including means for sealably engaging said connecting ends upon sliding said trays in respective pairs of grooves, the valve assembly including valve means for permitting flow from an oxygen supply into said intermediate oxygen conduit during the inhalation period to expand said oxygen bellows, and further valve means responsive to the pressure of the oxygen supply for opening automatically after a predetermined reduction of said pressure to direct oxygen from the intermediate oxygen conduit into the oxygen output conduit and hence into the breathing mixture bellows during the exhalation period.

31. A therapeutic ventilator as claimed in claim 30 in which the end members define a third pair of spaced-apart parallel grooves, said pairs of grooves extending longitudinally and said third pair of grooves being spaced longitudinally from said first and second pairs of grooves, the ventilator further comprising:

a connecting conduit coupleD to said breathing mixture tray and adapted to receive breathing mixture from the breathing mixture bellows and having a connecting end remote from the bellows;

a humidifier tray slidable in said third pair of grooves;

a humidifier coupled to said humidifier tray;

a humidifier conduit coupled to the humidifier tray and adapted to receive breathing mixture from the connecting conduit and to direct said breathing mixture into the humidifier; and

a coupling means attached to an end of said humidifier conduit remote from said humidifier and adapted to slidably receive said connecting end of the connecting conduit whereby the connecting conduit is pneumatically sealed to the humidifier conduit, said connecting conduit and said humidifier conduit being positioned on respective trays such that upon sliding the humidifier tray and the breathing mixture trays towards one another in the respective pairs of grooves, said connecting end of the connecting conduit engages in the coupling means.

32. A therapeutic ventilator as claimed in claim 31 in which the end members further define a fourth pair of spaced apart and parallel grooves positioned above said third pair of grooves, said ventilator further comprising:

a spirometer tray slidable in said fourth pair of grooves; and

a spirometer coupled to the spirometer tray and adapted to receive a patient'"'"''"'"'s exhaled breath.

33. A therapeutic ventilator as claimed in claim 32 and further comprising:

a humidifier outlet conduit coupled to the humidifier tray and adpated to receive humidified breathing mixture from the humidifier, the outlet conduit having an outer end remote from the humidifier;

a connecting tube coupled to the spirometer tray and adapted to lead exhaled breath into the spirometer, the connecting tube having an outer end remote from the spirometer, said outer ends extending in spaced-apart and parallel relation when the spirometer tray and the humidifier tray are engaged in respective pairs of grooves; and

a breathing control valve adapted to selectively provide passage for humidified breathing mixture from the humidifier outlet conduit to the patient and to provide passage for exhaled breath from the patient to the connecting tube, the breathing control valve being a push fit over the said outer ends and including means sealably engaging the outer ends.

34. A therapeutic ventilator for forcing a breathing mixture into a patient'"'"''"'"'s lungs during inhalation period and for permitting the patient to expel exhaled breath during an exhalation period, the ventilator comprising:

a pair of supporting end members;

a breathing mixture tray adapted to be movably mounted between the end members for assembly between and removal from the end members;

a breathing mixture bellows releasably coupled to said tray;

an oxygen conduit coupled to said tray and adapted to feed oxygen into the bellows, and having a connecting end;

an oxygen tray adapted to be movably mounted between the end members for assembly between and removal from the end members;

an oxygen bellows releasably coupled to the oxygen tray;

an intermediate oxygen conduit coupled to the oxygen tray and adapted to carry oxygen from the oxygen bellows, the intermediate oxygen conduit having a connecting end;

an oxygen control valve assembly fixedly coupled to the end members and including means for sealably engaging said connecting ends upon moving said trays into predetermined positions between the end members, the valve assembly including valve means to direct oxygen from the intermediate oxygen conduit into the oxygen output conduit during the exhalation period.

35. A therapeutic ventilator as claimed in claim 34 and further comprising:

a connecting conduit coupled to said breathing mixture tray and adapted to receive breathing mixture from the breathing mixture bellows;

a humidifier tray adapted to be movably mounted between the end members for assembly between and removal from the end members;

a humidifier coupled to said humidifier tray;

a humidifier conduit coupled To the humidifier tray and adapted to receive breathing mixture from the connecting conduit and to direct said breathing mixture into the humidifier; and

a coupling means attached to at least one of the connecting conduit and the humidifier conduit whereby the connecting conduit is pneumatically sealed to the humidifier conduit upon moving the humidifier tray and the breathing mixture tray towards one another between the end members.

36. A therapeutic ventilator as claimed in claim 35 and further comprising:

a spirometer tray adapted to be movably mounted between the end members for assembly between and removal from the end members; and

a spirometer coupled to the spirometer tray and adapted to receive a patient'"'"''"'"'s exhaled breath.

37. A therapeutic ventilator as claimed in claim 36 and which on assembly in the end members, the oxygen tray is above the breathing mixture tray, the spirometer tray is above the humidifier tray, and the humidifier tray and spirometer trays are spaced horizontally respectively from the breathing mixture tray and the oxygen tray.