Ventilator exhalation valve

• US 5,127,400 A
• Filed: 03/23/1990
• Issued: 07/07/1992
• Est. Priority Date: 03/23/1990
• Status: Expired due to Term

• Current Assignee: Bird Products Corporation (Becton, Dickinson & Co)
• Original Assignee: Bird Products Corporation (Becton, Dickinson & Co)
• Inventors: Hagen, Randy P., Guillaume, Darrell W., Dack, J. Kelly, DeVries, Douglas F., Williams, Malcolm R.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Lewis, Aaron J.
• Application Number:
  US07/498,207
• Time in Patent Office: 837 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/205.24
• US Class Current: 128/205.24
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• 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

Abstract

A ventilator exhalation valve for controlling the exhalation flow rate and pressure is disclosed. The valve includes a free-floating diaphragm which is biased against a fixed valve seat in an inhalation configuration of the valve so as to prevent flow through the valve in the reverse direction. As flow in the forward direction passes through the valve, the bias urging the diaphragm onto the valve seat is overcome and the diaphragm is separated from the valve seat, so as to contact a poppet affixed to a shaft. The shaft includes a ferromagnetic portion and is attached to linear actuator which is retained by substantially frictionless suspension system including a pair of substantially planar spring flexures. As the poppet moves in response to flow between the fixed valve seat and the diaphragm, ferromagnetic portion of the shaft is displaced relative to a fixed coil thereby inducing a current in a coil. The current is monitored to provide a feedback signal corresponding to the velocity of the poppet. The feedback signal may be used by a control mechanism to increase the pressure stability of the valve.

Claims

1. A ventilator exhalation valve for permitting the passage of fluid flow from the lungs of a patient to the atmosphere while precluding the passage of fluid from the atmosphere to the lungs, the valve having a forward fluid flow direction in which fluid flow through the valve is permitted and a reverse fluid flow direction in which fluid flow through the valve is prevented, the valve comprising:

(a) a housing assembly having an inlet port exposed to the lungs, an outlet port exposed to the atmosphere and a valve seat wherein the valve seat is intermediate of and fluidly connected to the inlet port and the outlet port;

(b) a diaphragm disposed proximal to the valve seat so as to selectively prevent flow through the valve, the diaphragm being displaced from the valve seat by fluid flow through the valve in the forward direction;

(c) a poppet disposed proximal to the diaphragm so that the poppet selectively contacts the diaphragm;

(d) a linear actuator mechanically connected to the poppet for selectively positioning the poppet relative to the valve seat; and

(e) a feedback assembly in communication with the poppet, providing a feedback signal corresponding to the velocity of the poppet relative to the valve seat for controlling the linear actuator.

2. The ventilator exhalation valve of claim 1 further comprising:

a pressure sense port in the housing assembly, the pressure sense port disposed between the valve seat and the inlet port, and fluidly connected to the inlet port.

3. The ventilator exhalation valve of claim 1 further comprising:

a suspension assembly for providing substantially frictionless motion of the poppet relative to the valve seat, the suspension system including at least one spring flexure connecting the poppet relative to the housing assembly so as to permit axial displacement of the poppet relative to the valve seat while substantially precluding radial displacement of the poppet relative to the valve seat.

4. A ventilator exhalation valve, comprising:

(a) a housing assembly having an inlet port, an outlet port, a pressure sense port and a valve seat, wherein the valve seat is disposed between the inlet port and the outlet port, and the pressure sense port is disposed between the valve seat and the inlet port;

(b) a resilient diaphragm disposed proximal to the valve seat such that upon a fluid flow from the inlet port to the outlet port the diaphragm is separated from the valve seat;

(c) a poppet disposed proximal to the diaphragm so that the diaphragm is between the poppet and the valve seat, wherein the poppet selectively contacts the diaphragm so as to permit independent motion of the poppet relative to the diaphragm;

(d) a suspension assembly for retaining the poppet relative to the housing, the suspension system including at least one substantially planar spring flexure connecting the poppet and the housing; and

(e) a feedback assembly in communication with the poppet for providing a feedback signal corresponding to the velocity of the poppet relative to the valve seat, the feedback assembly including a passive coil and a ferromagnetic element moveable relative to each other.

5. A ventilator exhalation valve, comprising:

(a) a housing assembly including an inlet port, an outlet port and a valve seat fluidly connected to and intermediate of the ports;

(b) a diaphragm disposed proximal to the valve seat and biased against the valve seat for selectively preventing fluid flow between the inlet port and the outlet port, and for preventing fluid flow from the outlet port to the inlet port;

(c) a linear actuator for selectively controlling the position of the diaphragm relative to the valve seat so as to regulate the amount of fluid flow between the inlet port and the outlet port; and

(d) a feedback assembly connected to the linear actuator for providing a feedback signal corresponding to the velocity of the diaphragm relative to the valve seat, the feedback assembly including a passive coil and a ferromagnetic element moveable relative to each other.

6. A ventilator exhalation valve, comprising:

(a) a housing assembly including an inlet port, an outlet port and a valve seat, wherein the valve seat is disposed intermediate of and fluidly connected to the inlet port and the outlet port;

(b) a diaphragm disposed proximal to the valve seat for selectively providing fluid flow between the inlet port and the outlet port;

(c) a linear actuator having a moveable member for physically contacting the diaphragm so as to regulate the fluid flow between the inlet port and the outlet port; and

(d) a suspension assembly for retaining the moveable member of the linear actuator relative to the housing wherein the suspension assembly includes a spring flexure attached to the moveable member for permitting axial motion of the moveable member relative to the housing while preventing radial motion of the moveable member relative to the housing.