Breathing assistance device with linear actuated gas regulating valve

Abstract

A breathing assistance device includes a gas regulating valve. The gas regulating valve is operated by a linear actuator. The linear actuator may include a movable member that moves an obstruction member between an open position and a closed position. The linear actuator is isolated from a gas flow path through the valve.

1 . (canceled) 
     
     
         2 . A gas regulating valve assembly, comprising:
 a linear actuator configured to for a gas regulating valve, comprising:
 a coil assembly; 
 a magnetic element inserted at least partly within the coil assembly; and 
 a central aperture adapted to receive a gas flow path therethrough; 
 wherein the coil assembly is adapted to move in a linear direction in response to electro-magnetic forces applied by the magnetic element; and 
   a gas regulating valve comprising:
 a housing including a gas flow passage that is configured to be located within the central aperture of the linear actuator; and 
 a membrane assembly; 
 wherein the linear actuator is isolated from gas flowing through the gas flow passage. 
   
     
     
         3 . The gas regulating valve assembly according to  claim 2  wherein the housing is formed of two portions, a proximal housing portion and a distal housing portion, the two portions being coupled together to secure the linear actuator within the housing. 
     
     
         4 . The gas regulating valve assembly according to  claim 3  wherein the proximal housing portion includes a protrusion that forms the gas flow passage, and wherein the gas flow passage is inserted through a first end of the central aperture of the linear actuator. 
     
     
         5 . The gas regulating valve assembly according to  claim 4  wherein the membrane assembly is inserted into the second end of the linear actuator and coupled to the gas flow passage of the proximal housing portion. 
     
     
         6 . The gas regulating valve assembly according to  claim 5  wherein the distal housing portion is inserted over the membrane assembly and linear actuator and couples to the proximal housing portion. 
     
     
         7 . The gas regulating valve assembly according to  claim 2 , further comprising a sensing tube attached to the housing. 
     
     
         8 . The gas regulating valve assembly according to  claim 3  wherein one of the proximal housing portion and the distal housing portion includes at least one aperture adapted to allow gas passing through the valve to escape to atmosphere. 
     
     
         9 . The gas regulating valve assembly according to  claim 8  wherein the membrane assembly comprises an obstruction element, an actuator ring and a clamping ring, and the obstruction element is movable between a closed position where it closes off the at least one aperture and an open position where it opens the at least one aperture. 
     
     
         10 . The gas regulating valve assembly according to  claim 9  wherein the obstruction element is coupled to the linear actuator such that the linear actuator causes movement of the obstruction element between the open and closed positions. 
     
     
         11 . The gas regulating valve assembly according to  claim 9  wherein the obstruction element is a membrane. 
     
     
         12 . The gas regulating valve assembly according to  claim 11  wherein the membrane functions to control the opening of the least one aperture and to isolate the linear actuator from the gas flow path. 
     
     
         13 . The gas regulating valve assembly according to  claim 11  wherein the membrane acts as a return spring to ensure the at least one aperture is open to atmosphere in case of power failure of the gas regulating valve. 
     
     
         14 . A gas regulating valve assembly, comprising:
 a linear actuator for a gas regulating valve, comprising:
 a yoke; 
 a bobbin that is movably mounted inside the yoke and that has first and second arms that extend from a first end of the bobbin, wherein a wire coil is wrapped around the bobbin; 
 a flexible circuit assembly having a central portion that is attached to the yoke and first and second extensions that extend from the central portion and that are attached to the first and second arms of the bobbin, respectively, wherein first and second electrical contacts are formed on the central portion, the first and second electrical contacts being coupled, respectively, to first and second ends of the wire coil; and 
 a magnet that is attached to the yoke; 
 wherein central portions of the housing, the yoke, the bobbin and the magnet are open to thereby form a passageway through a center of the linear actuator; and 
   a gas regulating valve comprising:
 a first housing portion configured to be attached to a gas delivery tube; 
 a second housing portion configured to be attached to a patient interface, wherein one of the first and second housing portions extends at least partially through the passageway in the center of the linear actuator; and 
 a membrane assembly that is coupled between the first and second housing portions such that a gas passing through the first and second housing portions and through the membrane assembly is isolated from the linear actuator. 
   
     
     
         15 . The gas regulating valve assembly of  claim 14 , wherein the other of the first and second housing portions is attached to and at least partially surrounds an exterior of a cylindrical housing of the linear actuator. 
     
     
         16 . The gas regulating valve assembly of  claim 14 , wherein at least one aperture is formed in one of the first and second housing portions, and wherein a portion of the membrane assembly comprises an obstruction member that is movable between a closed position at which it closes off the at least one aperture and an open position at which it opens the at least one aperture. 
     
     
         17 . The gas regulating valve assembly of  claim 16 , wherein the membrane assembly is coupled to the bobbin of the linear actuator such that the linear actuator can move the obstruction member from the open position to the closed position. 
     
     
         18 . The gas regulating valve assembly of  claim 17 , wherein the at least one aperture is formed on the first housing portion, wherein the first housing portion comprises a cylindrical sealing surface, and wherein the linear actuator brings a sealing surface on the obstruction member into engagement with the sealing surface on the first housing portion to close off the at least one aperture on the first housing portion. 
     
     
         19 . The gas regulating valve assembly of  claim 17 , wherein the membrane assembly comprises:
 a flexible cylindrical membrane that is coupled between the first housing portion and the second housing portion; and   a substantially rigid actuating ring that is coupled to a central portion of the flexible cylindrical membrane, wherein a lower end of the bobbin of the linear actuator pushes against the actuating ring to cause the obstruction member to move from the open position to the closed position.   
     
     
         20 . The gas regulating valve assembly of  claim 14 , further comprising a flow restrictor that is coupled to the membrane assembly, wherein the flow restrictor at least partially extends through the central passageway of the linear actuator, and wherein the flow restrictor is coupled to one of the first and second housing portions. 
     
     
         21 . The gas regulating valve assembly of  claim 14 , wherein at least one sensor aperture is formed in the second housing portion, and wherein the sensor aperture is configured to couple an interior of the second housing portion to a sensor tube. 
     
     
         22 . A breathing assistance device comprising the gas regulating valve assembly of  claim 14 . 
     
     
         23 . A method of manufacturing a linear actuator, comprising:
 inserting a hollow bobbin having a wire coil wound thereon inside a hollow yoke;   attaching a central portion of a flexible circuit assembly to the yoke, the flexible circuit assembly having first and second extensions protruding from the central portion;   coupling first and second ends of the wire coil to the first and second extensions of the flexible circuit assembly;   inserting a hollow magnet inside the bobbin; and   attaching the magnet to the yoke.   
     
     
         24 . The method of  claim 23 , wherein the hollow bobbin has first and second arms that extend from a first end of the bobbin, the method further comprising attaching ends of the first and second extensions of the flexible circuit assembly, respectively, to ends of the first and second arms of the bobbin. 
     
     
         25 . The method of  claim 24 , wherein the ends of the first and second extensions of the flexible circuit assembly are attached to the ends of the first and second arms of the bobbin by heat staking. 
     
     
         26 . The method of  claim 25 , wherein the ends of the first and second extensions of the flexible circuit assembly each have an aperture therethrough, wherein a protrusion is formed at the end of each of the first and second arms of the bobbin, and wherein attaching ends of the first and second arc-shaped extensions of the flexible circuit assembly to ends of the first and second arms of the bobbin comprises inserting the protrusions on the arms of the bobbin into the apertures in the ends of the arc-shaped extensions. 
     
     
         27 . The method of  claim 23 , further comprising inserting the yoke, bobbin and magnet into a housing and coupling the yoke to the housing. 
     
     
         28 . The method of  claim 27 , wherein the housing includes first and second electrical contacts that are coupled to a wire assembly, wherein electrically conductive paths are formed in the flexible circuit assembly, the electrically conductive paths electrically coupling the first and second ends of the wire coil to first and second contacts located on the central portion of the flexible circuit assembly, and wherein the step of inserting the yoke, bobbin and magnet into the housing causes the first and second contacts on the flexible circuit assembly to couple to the first and second electrical contacts on the housing. 
     
     
         29 . The method of  claim 23 , further comprising mounting a hollow pole piece inside the bobbin such that ends of the magnet and the pole piece abut one another.