초록 ▼

A flow sensor for a medical ventilator system is disclosed herein. The flow sensor includes a valve assembly having a valve seat, and a valve flap attached to the valve seat. The valve flap is composed of an elastomeric material configured to generate a pre-load that biases the valve flap into engag

A flow sensor for a medical ventilator system is disclosed herein. The flow sensor includes a valve assembly having a valve seat, and a valve flap attached to the valve seat. The valve flap is composed of an elastomeric material configured to generate a pre-load that biases the valve flap into engagement with the valve seat such that the valve assembly remains closed in the absence of an externally applied force. The flow sensor also includes a pressure transducer configure to measure a first pressure level at an upstream position relative to the valve assembly, and a second pressure level at a downstream position relative the valve assembly. The flow sensor also includes a processor configured to estimate the flow rate of a fluid passing through a medical ventilator system based on the first and second pressure levels.

대표청구항 ▼

1. A flow sensor for a medical ventilator system comprising: a valve assembly comprising:a valve seat comprising an attachment aperture, a seat ring, and a pin that extends from the valve seat past the seat ring; anda valve flap attached to the valve seat, the valve flap being composed of an elastom

1. A flow sensor for a medical ventilator system comprising: a valve assembly comprising:a valve seat comprising an attachment aperture, a seat ring, and a pin that extends from the valve seat past the seat ring; anda valve flap attached to the valve seat, the valve flap being composed of an elastomeric material and the valve flap comprising a protrusion configured to be received within the attachment aperture to retain the valve flap to the valve seat;wherein the elastomeric material of the protrusion generates a pre-load that biases the valve flap into engagement with the valve seat such that the valve assembly remains closed in the absence of an externally applied force and the valve flap engages the pin to limit engagement between the valve flap and the seat ring when the valve assembly is closed;a pressure transducer configured to measure a first pressure level at an upstream position relative to the valve assembly, and a second pressure level at a downstream position relative the valve assembly; anda processor connected to the pressure transducer, said processor configured to estimate the flow rate of a fluid passing through a medical ventilator system based on the first and second pressure levels. 2. The flow sensor of claim 1, wherein the pre-load generated by the elastomeric material of the valve flap is small enough to be overcome by a typical patient's inspiration and/or expiration. 3. The flow sensor of claim 1, wherein the valve flap comprises a pair of protrusions collectively configured to retain the valve flap to the valve seat, and to resist valve flap rotation. 4. The flow sensor of claim 1, wherein the valve flap protrusion comprises a tapered portion adapted to facilitate the insertion of the valve flap protrusion into the attachment aperture of the valve seat. 5. The flow sensor of claim 1, wherein the valve flap protrusion is elastically deformed during the process of attaching the valve flap to the valve seat, and wherein the elastic deformation of the valve flap protrusion biases the valve flap into engagement with the valve seat. 6. The flow sensor of claim 1, wherein the valve seat is configured to at least partially engage the valve flap when the valve assembly is closed. 7. The flow sensor of claim 1, further comprising a high-pressure tube and a low-pressure tube pneumatically coupled with the pressure transducer. 8. A medical ventilator system comprising: a ventilator;a breathing circuit pneumatically coupled with the ventilator and conveying a flow of medical gas;a flow sensor pneumatically coupled with the breathing circuit, said flow sensor comprising:a valve assembly comprising:a valve seat including a snake generally perpendicular to the flow of medical gas, a seat ring, and a pin; anda valve flap composed of an elastomeric material, said valve flap comprising a protrusion extending, away from the valve flap in an axial direction into the flow of medical gas, the protrusion deforms in the axial direction when connected to the valve seat to retain the valve flap to the valve seat;wherein the elastic deformation of the valve flap protrusion in the axial direction generates a pre-load that biases the valve flap into engagement with the pin and the surface of the valve seat such that the valve assembly remains closed in the absence of a predetermined medical gas flow and the pin maintains a partial separation between portions of the valve flap and the valve seat;a pressure transducer configured to measure a first pressure level at an upstream position relative to the valve assembly, and a second pressure level at a downstream position relative the valve assembly; anda processor connected to the pressure transducer, said processor configured to estimate the flow rate of the medical gas passing through the medical ventilator system based on the first and second pressure levels. 9. The medical ventilator system of claim 8, wherein the pre-load generated by the elastic deformation of the valve flap protrusion is small enough to be overcome by a typical patient's inspiration and/or expiration. 10. The medical ventilator system of claim 8, wherein the valve seat comprises an attachment aperture configured to receive the valve flap protrusion. 11. The medical ventilator system of claim 8, wherein the valve flap comprises a pair of protrusions collectively configured to retain the valve flap to the valve seat, and to resist valve flap rotation. 12. The medical ventilator system of claim 8, wherein the valve flap protrusion comprises a tapered portion adapted to facilitate the insertion of the valve flap protrusion into the attachment aperture of the valve seat. 13. The medical ventilator system of claim 8, wherein the seat ring is configured to partially engage the valve flap when the valve assembly is closed. 14. The medical ventilator system of claim 8, further comprising: an attachment aperture in the valve seat configured to receive the protrusion, wherein the attachment aperture is of a first cross-sectional diameter and the protrusion comprises a flange portion of a second cross-sectional diameter, configured to engage the attachment aperture; andwherein the second cross-sectional diameter is larger than the first cross-sectional diameter, and engagement of the first portion with the attachment aperture retains the valve flap to the valve seat. 15. The medical ventilator system of claim 14, wherein the attachment aperture is of a first length through the valve seat; wherein the protrusion comprises a reduced diameter position, of a second length, that extends between the valve flap and the flange portion of the protrusion; andwherein the second length is shorter than the first length and engagement of the flange portion with the attachment aperture elastically deforms the reduced diameter portion in the axial direction, and the elastic deformation of the reduced diameter portion generates the pre-load on the valve flap. 16. A method for estimating a flow rate of a fluid passing through a medical ventilator system comprising: providing a breathing circuit providing a valve assembly disposed at least partially within the breathing circuit comprising:providing a valve flap composed of an elastomeric material;assembling the valve flap to a valve seat such that the elastomeric material of a protrusion of the valve flap is elastically deformed in an axial direction during the assembly process, wherein the elastic deformation of the protrusion generates a pre-load that biases the valve flap into at least partial engagement with a seat ring of the valve seat perpendicular to the fluid and into at least partial engagement with a pin of the valve seat protruding past the seat ring such that the valve assembly remains closed in the absence of a predetermined medical gas flow while maintaining partial separation between the valve flap and the seat ring;estimating with a first pressure transducer a first pressure level within the breathing circuit at art upstream position relative to the valve assembly;estimating with a second pressure transducer a second pressure level within the breathing circuit at a downstream position relative to the valve assembly;estimating with a processor a flow rate of a fluid passing through the breathing circuit based on the first and second pressure levels. 17. The method of claim 16, further comprising selecting the magnitude of the pre-load such that the valve assembly automatically opens in response to a patient's inspiration and/or expiration.