Controllable expiration valve arrangement for a ventilating apparatus

• US 5,063,925 A
• Filed: 06/30/1989
• Issued: 11/12/1991
• Est. Priority Date: 07/07/1988
• Status: Expired due to Fees

• Current Assignee: Dragerwerk AG
• Original Assignee: Dragerwerk AG
• Inventors: Gebhardt, Peter, Eifrig, Reinhard, Weismann, Dieter, Frank, Helge, Hecker, Eric
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Asher, Kimberly L.
• Application Number:
  US07/374,066
• Time in Patent Office: 865 Days
• Field of Search: 128/205.24, 128/205.19, 128/204.26, 128/204.18
• US Class Current: 128/205.24
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• 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: A61M 16/207 Membrane valves with pneumatic amplification stage, i.e. having master and slave membranes

Abstract

The invention is directed to a controllable expiration valve having a control valve for generating an end expiratory overpressure with the control valve providing the changeable control pressure. The expiration valve is improved so that it is made controllable for compensating dynamic end expiratory overpressure. For this purpose, the membrane chamber of the expiration valve as well as the outflow chamber of the control valve are connected with a device for generating an underpressure.

Claims

1. A controllable expiration valve arrangement for a ventilating apparatus having an expiration branch line said expiration branch line producing a dynamic flow resistance as the exhaled breathing gas flows therethrough said dynamic flow resistance producing a dynamic end expiratory pressure in the expiration branch line, the arrangement comprising:

an expiration valve having an expiration valve housing and membrane valve means for partitioning said housing into a control chamber and a membrane chamber;

an inlet for admitting breathing gas into said membrane chamber from the branch line of the ventilating apparatus;

said membrane valve means being switchable between a closed position during inspiration so as to close said inlet and an open position during expiration so as to open said inlet to communicate with said membrane chamber;

means for compensating for said dynamic positive end expiratory pressure comprising;

a control valve for maintaining a desired end expiratory pressure during expiration by providing a changeable pressure to said control chamber for actuating said membrane valve means to switch between said closed end said open position, said control valve having a control valve housing and a control membrane for partitioning said control valve housing into first and second chambers;

underpressure means for generating an underpressure in said first and second chambers of said control valve and in said membrane chamber of said expiration valve corresponding to said dynamic positive end expiratory pressure.

control gas line means communicating with said control chamber of said expiration valve and said control membrane for supplying a control gas under pressure thereto;

said control valve including valve seat means communicating with said control gas line means;

said control membrane being mounted in said control valve housing for coacting with said valve seat means for closing said valve seat means; and

,

said control valve further including force applying means for applying a first force to said control membrane during said inspiration and for applying a second force to said control membrane during expiration which is reduced to be less than said first force for reducing the pressure of said control gas applied to said membrane valve means of said expiration valve to cause said membrane valve means to open, and for compensating for the dynamic end expiratory pressure acting in the branch line in combination with said underpressure means.

2. The controllable expiration valve arrangement of claim 1, said underpressure means comprising a suction pump connected to said first and second chambers and said membrane chamber.

3. A controllable expiration valve arrangement for a ventilating apparatus, the arrangement comprising:

an expiration valve having an expiration valve housing and membrane valve means for partitioning said housing into a control chamber and a membrane chamber;

said membrane valve means being switchable between a closed position during inspiration and an open position during expiration;

a control valve for providing a changeable pressure to said control chamber for actuating said membrane valve means to switch between said positions, said control valve having a control valve housing and closure means for partitioning said control valve housing into first and second chambers;

control gas line means communicating with said control chamber and said closure means for supplying a control gas under pressure thereto;

said closure means including valve seat means communicating with said control gas line means;

a closure member for closing said valve seat means; and

, force applying means for applying a first force to said closure member during said inspiration and for applying a second force to said closure member during expiration which is less than said first force thereby changing the pressure of said control gas applied to said membrane valve means;

underpressure means for generating an underpressure in at least one of said first and second chambers of said control valve and in said membrane chamber of said expiration valve;

said closure member being a control membrane partitioning said control chamber housing into said first and second chambers;

said force applying means being an actuator for actuating said control membrane; and

,

said underpressure means being connected to both of said first and second chambers for generating an underpressure therein.

4. The controllable expiration valve arrangement of claim 3, said actuator comprising a plunger-coil arrangement having a moveable push rod connected to said control membrane and biasing the latter so as to close the same against said valve seat means.

5. A controllable expiration valve arrangement for a ventilating apparatus, the arrangement comprising:

an expiration valve having an expiration valve housing and membrane valve means for partitioning said housing into a control chamber and a membrane chamber;

said membrane valve means being switchable between a closed position during inspiration and an open position during expiration;

a control valve having a control valve housing and closure means for partitioning said control valve housing into first and second chambers;

first control gas supply means for supplying a first control gas at a first control pressure;

second control gas supply means for supplying a second control gas at a second control pressure;

switchover means movable into a first switching position for connecting said first control gas supply means to said control chamber of said expiration valve during inspiration to move said membrane valve means into said closed position and then movable out of said first switching position and into a second switching position for connecting said second control gas supply means to said control chamber of said expiration valve during expiration to switch said membrane valve means into said open position while at the same time also connecting said second control gas supply means to said closure means;

said closure means including valve seat means disposed in said first chamber;

a valve closure member for coacting with said valve seat means; and

, adjustable force means for applying an adjusted force to said valve closure member for adjusting the magnitude of said second control pressure in said control chamber during said expiration; and

,

underpressure means for generating an underpressure in at least one of said first and second chambers of said control valve and in said membrane chamber of said expiration valve.