Patent ID: 8118024

Claim:
A bias valve apparatus for attenuating pulsating gas flow from a gas source to a flow-receiving device, the bias valve apparatus comprising: a housing assembly, comprising: an annular housing chamber opening to a housing outlet fluidly connected to the flow-receiving device and to a housing inlet fluidly connected to the gas source; and a housing having a housing sidewall and a housing end wall, the housing inlet being formed on an end opposite the housing end wall, the housing outlet being formed on the housing sidewall; a hollow cylinder fixedly mounted within the housing assembly and having a cylinder end wall and a cylinder sidewall, the cylinder sidewall being disposed in spaced coaxial relation to the housing sidewall to define the housing chamber therebetween, the cylinder being open on an end coincident with the housing inlet; and an annular valve seat fixedly mounted to the housing inlet and having a seat interface; a poppet slid ably disposed within the cylinder and reciprocatively moveable therewithin, wherein: the poppet includes a poppet side and opposing poppet ends; a cylinder chamber is defined between the cylinder end wall and one of the poppetends, and the other one of the poppet ends is configured to be sealingly engageable to the seat interface and defining a seat area; and a spring having a spring preload sufficient to bias the poppet toward the seat interface; and wherein the bias valve apparatus is used in conjunction with a ventilator having an exhalation control module fluidly connected to the bias valve apparatus; wherein the gas source includes a Roots-type blower assembly and the flow-receiving device includes a patient circuit fluidly connected to an opposite side of the bias valve apparatus, and wherein the exhalation control module is configured to operate an exhalation valve connected to the patient circuit.