Exhalation valve assembly

• US 6,073,630 A
• Filed: 11/03/1997
• Issued: 06/13/2000
• Est. Priority Date: 02/28/1994
• Status: Expired due to Term

• Current Assignee: Flight Medical, Ltd.
• Original Assignee: Flight Medical, Ltd.
• Inventors: Adahan, Carmeli
• Primary Examiner(s): Lewis, Aaron J.
• Application Number:
  US08/963,646
• Time in Patent Office: 953 Days
• Field of Search: 128/204.21, 128/204.23, 128/204.26, 128/205.24, 137/494, 137/505.47, 137/487.5, 251/30.01, 251/58, 251/129.01, 251/129.15, 251/129.18, 251/129.2
• US Class Current: 128/205.24
• CPC Class Codes: A61M 16/0072 Tidal volume piston pumps
• CPC Class Codes: A61M 16/021 operated by electrical means A61M16/202 – A61M16/205 take precedence
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• 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: A61M 16/208 Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• CPC Class Codes: A61M 16/209 Relief valves

Abstract

A reciprocating pump particularly useful in ventilator apparatus includes a piston reciprocatable axially within a cylinder and dividing its interior into an inlet chamber and an outlet chamber, a wall fixed within the inlet chamber, and a drive housing fixed to the wall. The drive housing includes a motor, a rotor rotatable by the motor, a nut rotatable within the drive housing, and a screw threadedly coupled at one end to the nut and fixed at its opposite end to the piston. The piston is substantially unrestrained for axial and rotary movement such that forward and reverse rotation of the nut by the motor reciprocates the screw and the piston axially of the cylinder, and also permits the screw and the piston to rotate with respect to the cylinder to thereby even out wear between the piston and cylinder.

Claims

1. An exhalation valve assembly for use with a respiratory pump having an outlet, said assembly comprising:

an exhalation valve comprising an inlet port connectable to the outlet of the pump;

an outlet port adapted to be connected to a patient, an exhalation port leading to the atmosphere, a valve member of the exhalation valve selectively connecting the outlet port to said exhalation port, and a control chamber for controlling the operation of said valve member in response to the pressure in said control chamber; and

a control valve for controlling the pressure in said control chamber to increase the pressure therein during inspiration to cause the valve member of the exhalation valve to disconnect the outlet port from said exhalation port, and to decrease the pressure in the control chamber during exhalation to thereby cause the valve member of the exhalation valve to connect the outlet port to the exhalation port of the exhalation valve;

wherein said control valve includes;

presettable modulating means for presetting a pressure in the control chamber during exhalation to any predetermined partial pressure to thereby preset the exhalation pressure to open said exhalation valve, comprising

an inlet port connectable to an outlet of the pump;

a control port connected to said control chamber of the exhalation valve;

a vent leading to the atmosphere;

a valve member of the control valve movable over a continuum of positions between a first position during inspiration to open a first passageway connecting the control chamber of the exhalation valve to the inlet port of the control valve, and thereby to the outlet port of the pump, and a second position during exhalation to close said first passageway and to open a second passageway connecting the control chamber of the exhalation valve to said vent leading to the atmosphere;

a solenoid having an armature controlling the pressure in the control chamber of the exhalation valve according to the energization of the solenoid, and capable of providing any of no, partial or full energization; and

a circuit for controlling the energization of said solenoid such that during inspiration it moves said valve member of the control valve fully or partially to said first position, and during exhalation it moves said valve member of the control valve to said second position.

2. The exhalation valve assembly according to claim 1, wherein said valve member of the control valve includes a hollow stem whose interior is exposed at one end to the atmosphere;

and a diaphgram engageable with the opposite end of said hollow stem;

said armature of the solenoid acting against said diaphragm to urge the hollow stem fully or partially to said first position during inspiration.

4. The exhalation valve assembly according to claim 1, wherein said solenoid comprises means permitting said armature to pivot about an edge thereof, thereby providing an essentially hysteresis-free control of said exhalation valve.

3. An exhalation valve assembly for use with a respiratory pump having an outlet, said assembly comprising:

an exhalation valve comprising an inlet port connectable to the outlet of the pump;

an outlet port adapted to be connected to a patient, an exhalation port leading to the atmosphere, a valve member of the exhalation valve selectively connecting the outlet port to said exhalation port, and a control chamber for controlling the operation of said valve member in response to the pressure in said control chamber; and

a control valve for controlling the pressure in said control chamber to increase the pressure therein during inspiration to cause the valve member of the exhalation valve to disconnect the outlet port from said exhalation port, and to decrease the pressure in the control chamber during exhalation to thereby cause the valve member of the exhalation valve to connect the outlet port to the exhalation port of the exhalation valve;

said control valve including presettable means for presetting a predetermined partial pressure in the control chamber during exhalation to thereby preset the exhalation pressure to open said exhalation valve, and wherein said control valve comprises;

an inlet port connectable to an outlet of the pump;

a control port connected to said control chamber of the exhalation valve;

a vent leading to the atmosphere;

a valve member of the control valve movable to a first position during inspiration to open a first passageway connecting the control chamber of the exhalation valve to the inlet port of the control valve, and thereby to the outlet port of the pump, or to a second position during exhalation to close said first passageway and to open a second passageway connecting the control chamber of the exhalation valve to said vent leading to the atmosphere;

a solenoid having an armature controlling the pressure in the control chamber of the exhalation valve according to the energization of the solenoid; and

a circuit for controlling the energization of said solenoid such that during inspiration it moves said valve member of the control valve to said first position, and during exhalation it moves said valve member of the control valve to said second position;

wherein said valve member includes a hollow stem whose interior is exposed at one end to the atmosphere; and

a diaphragm engageable with the opposite end of said hollow stem;

said armature of the solenoid acting against said diaphragm to urge the hollow stem to said first position during inspiration,

wherein said valve member further includes an elastomeric tube enclosing said hollow stem and effective to urge said hollow stem to said second position during exhalation.