Mechanical ventilation system utilizing bias valve

• US 10,118,011 B2
• Filed: 09/04/2015
• Issued: 11/06/2018
• Est. Priority Date: 08/04/2003
• Status: Active Grant

• Current Assignee: Vyaire Medical 203 Incorporated (Cardinal Health, Inc.)
• Original Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Inventors: DeVries, Douglas F., Allum, Todd W.
• Primary Examiner(s): Dixon, Annette
• Application Number:
  US14/846,075
• Publication Number:
  US 20150374950A1
• Time in Patent Office: 1,159 Days
• Field of Search: 12820024, 12820418, 12820421, 12820423, 12820426, 12820524, 137522, 137523, 137529, 137534, 137538, 13754319, 251 65, 251 83
• CPC Class Codes: A61M 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 16/208 Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/003 with a flowmeter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/42 Reducing noise
• CPC Class Codes: F04C 18/126 with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
• CPC Class Codes: F04C 2220/24 for metering throughflow
• CPC Class Codes: F04C 28/24 characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valvesF04C28/10 takes precedence
• CPC Class Codes: F04C 29/0035 Equalization of pressure pulses silencing F04C29/06

Abstract

A portable mechanical ventilator having a Roots blower provides a desired gas flow and pressure to a patient circuit. The mechanical ventilator includes a flow meter operative to measure gas flow produced by the Roots blower and an exhalation control module configured to operate an exhalation valve connected to the patient circuit. A bias valve connected between the Roots blower and the patient circuit is specifically configured to generate a bias pressure relative to the patient circuit pressure at the exhalation control module. The bias valve attenuates pulsating gas flow produced by the Roots blower such that gas flowing to the mass flow meter exhibits a substantially constant pressure characteristic. The bias pressure facilitates closing of the exhalation valve at the start of inspiration, regulates positive end expiratory pressure during exhalation, and purges sense lines via a pressure transducer module.

Claims

1. An apparatus for attenuating a gas flow from a gas source to a patient circuit, the apparatus comprising a bias valve connected between the gas source and the patient circuit, the bias valve comprising an inlet connected to the gas source and comprising a valve seat, an outlet connected to the patient circuit, a cavity, and a poppet, the poppet configured to reciprocate within the cavity to engage against the valve seat to resist gas flow into the bias valve in a closed position, and disengage from the valve seat to permit gas flow into the bias valve in an open position;

wherein a poppet clearance is defined between the poppet and the cavity, the poppet clearance sized to generate viscous damping of the gas flow when gas passes through the poppet clearance during poppet reciprocation.

2. The apparatus of claim 1, wherein a spring biases the poppet against the valve seat such that an elevated pressure is provided at the bias valve inlet relative to the bias valve outlet.

3. The apparatus of claim 2, wherein:

a pressure transducer module is fluidly connected to the bias valve, wherein the pressure transducer module receives a bias pressure due to the elevated drive pressure; and

a sense line system including at least one of an airway sense line and a flow sense line is connected between the patient circuit and the pressure transducer module, wherein the pressure transducer module is operative to purge the sense line system using the bias pressure.

4. The apparatus of claim 1, wherein a mass flow meter is interposed between the gas source and the bias valve inlet, the mass flow meter configured to measure a gas flow rate of the gas source.

5. The apparatus of claim 1, wherein the gas flow from the gas source is a pulsating gas flow.

6. The apparatus of claim 1, wherein the gas source includes a blower assembly.

7. The apparatus of claim 6, wherein the blower assembly includes a Roots blower.

8. The apparatus of claim 1, wherein the poppet has a mass sufficient to generate inertial damping of the pulsating gas flow.

9. The apparatus of claim 8, wherein a mass element is connected to the poppet to achieve a desired inertial dampening characteristic.

10. The apparatus of claim 1, wherein an exhalation control module is connected to the bias valve inlet, and an exhalation valve, controlled by the exhalation control module, is connected to the patient circuit.

11. A method for attenuating a gas flow from a gas source to a patient circuit, comprising:

connecting a bias valve between the gas source and the patient circuit, the bias valve comprising an inlet connected to the gas source, an outlet connected to the patient circuit, a cavity, and a poppet configured to reciprocate within the cavity;

engaging the poppet with a valve seat at the bias valve inlet in a closed position and disengaging the poppet from the valve seat in an open position for respectively resisting and allowing gas to flow out of the bias valve outlet; and

viscously dampening the gas flow when the gas passes through a poppet clearance between the poppet and the cavity during poppet reciprocation.

12. The method of claim 11, further comprising biasing the poppet against the valve seat such that an elevated pressure is provided at the bias valve inlet relative to the bias valve outlet.

13. The method of claim 12, further comprising:

receiving, at a pressure transducer module fluidly connected to the bias valve, a bias pressure due to the elevated drive pressure;

connecting a sense line system including at least one of an airway sense line and a flow sense line between the patient circuit and the pressure transducer module; and

purging the sense line system using the bias pressure and the pressure transducer module.

14. The method of claim 11, further comprising interposing a mass flow meter between the gas source and the bias valve inlet, the mass flow meter configured to measure a gas flow rate of the gas source.

15. The method of claim 11, further comprising inertially dampening the gas flow using the poppet, wherein the gas flow from the gas source is a pulsating gas flow.

16. The method of claim 15, further comprising connecting a mass element to the poppet to achieve a desired inertial dampening characteristic.

17. A ventilator system comprising:

a pulsating gas source;

a patient circuit;

an exhalation valve connected to the patient circuit;

an exhalation control module configured to operate the exhalation valve; and

a bias valve connected between the gas source and the patient circuit, the bias valve comprising an inlet connected to the gas source and comprising a valve seat, and an outlet connected to the patient circuit, a cavity fluidly coupled to the inlet and the outlet, and a poppet configured to reciprocate within the cavity to engage against the valve seat to resist gas flow into the bias valve in a closed position, and disengage from the valve seat to permit gas flow into the bias valve in an open position.

18. The system of claim 17, wherein a poppet clearance is defined between the poppet and the cavity to generate viscous damping of the gas flow when gas passes through the poppet clearance during poppet reciprocation.