Systems and method for delivery of therapeutic gas to patients in need thereof using enhanced breathing circuit gas (BCG) flow measurement

Patent metadata

Field	Value
Publication number	US-11471641-B2
Application number	US-201916253834-A
Country	US
Kind code	B2
Filing date	Jan 22, 2019
Priority date	Apr 1, 2014
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

The present invention generally relates to systems and method for delivery of therapeutic gas to patients in need thereof using enhanced breathing circuit gas (BCG) flow measurement. At least some of these enhanced BCG flow measurements can be used to address some surprising phenomena that may, at times, occur when wild stream blending therapeutic gas into breathing gas that a patient receives from a breathing circuit affiliated with a ventilator. Utilizing at least some of these enhanced BCG flow measurements the dose of therapeutic gas wild stream blended into breathing gas that the patient receives from a ventilator can at least be more accurate and/or over delivery of therapeutic gas into the breathing gas can be avoided and/or reduced.

First claim

What is claimed is:

1. A method of administering a therapeutic gas to a patient, the method comprising:
measuring a flow direction of a breathing gas through and/or in fluid communication with a breathing circuit affiliated with a ventilator, wherein flow is in a forward direction when flowing from the ventilator towards the patient and in a reverse direction when flowing from the patient towards the ventilator;
determining the breathing gas flow is in the forward direction, opening a control valve of a nitric oxide delivery system in communication with a flow of a breathing gas, and delivering the therapeutic gas into the breathing gas;
determining the breathing gas flow is in the reverse direction, closing the control valve of the nitric oxide delivery system, and ceasing delivery of the therapeutic gas into the breathing gas;
determining a volume of reverse flow;
determining the breathing gas resumed flow in the forward direction
determining a volume of resumed forward flow;
receiving information indicative of ventilator type;
determining the ventilator type wherein the ventilator type is a BiPAP ventilator and/or a ventilator affiliated with single limb breathing circuit; and
compensating for flow in the reverse direction based on if the ventilator is determined to be the BiPAP ventilator and/or the ventilator affiliated with single limb breathing circuit,
wherein the therapeutic gas comprises nitric oxide.

2. The method of claim 1 , wherein if the ventilator is a BiPAP ventilator and/or affiliated with single limb breathing circuit, compensating for at least a portion of the flow in the reverse direction comprises not delivering therapeutic gas into the breathing circuit until after an amount of forward flow has been measured equaling at least a portion of the reverse flow measured; and
wherein if the ventilator is not a BiPAP ventilator and/or affiliated with a single limb breathing circuit, compensating for at least a portion of the flow in the reverse direction comprises not delivering therapeutic gas into the breathing circuit until after an amount of forward flow has been measured equaling the reverse flow measured.

3. The method of claim 2 , wherein not delivering therapeutic gas into the breathing circuit until after the volume of resumed forward flow has been measured equaling at least a portion of the volume of reverse flow measured comprises not delivering therapeutic gas into the breathing circuit until after the volume of resumed forward flow has been measured equaling the lesser of (i) the volume of reverse flow measured or (ii) a dead space volume.

4. The method of claim 3 , wherein the dead space volume is entered by a user and/or is communicated from the ventilator; and the method optionally further comprises providing instructions to a user to add a segment of breathing circuit between the patient and at least one bi-directional breathing circuit gas (BCG) flow sensor for measuring the volume of reverse flow.

5. The method of claim 2 , wherein the flow measurement is from the ventilator.

6. The method of claim 1 , wherein compensating for the flow in the reverse direction ensures that a desired dose of therapeutic gas is not over delivered, overdosed, under delivered, and/or under dosed.

7. The method of claim 1 , further comprising measuring carbon dioxide in at least a portion of the reverse flow measured, and wherein compensating for the flow in the reverse direction further comprises delivering therapeutic gas into the breathing circuit for the reverse flow measured that contains carbon dioxide and not delivering therapeutic gas into the breathing circuit for the reverse flow measured that does not contain carbon dioxide.

8. The method of claim 1 , wherein the flow of the breathing gas through and/or in fluid communication with the breathing circuit affiliated with the ventilator is measured by at least one bi-directional breathing circuit gas (BCG) flow sensor, and the bi-directional BCG flow sensor includes one or more of (i) has an operating range for forward flow that is greater than an operating range for reverse flow and (ii) has separate calibration data sets and/or calibration routines for forward and reverse flow.

9. A nitric oxide delivery system comprising:
an injector module for delivering a therapeutic gas into a breathing gas in a breathing circuit, the injector module comprising:
an injector body having a first opening and a second opening, the first opening and the second opening being configured to couple the injector module to the breathing circuit;
a therapeutic gas inlet configured to receive the therapeutic gas and enable injection of the therapeutic gas into the breathing gas in the breathing circuit flowing through the injector module; and
at least one bi-directional breathing circuit gas (BCG) flow sensor capable of measuring breathing gas flow in a forward direction and in a reverse direction; and

a control valve in communication with the therapeutic gas inlet; and
a control module in communication with the BCG flow sensor and the control valve, wherein the control module provides the therapeutic gas to the therapeutic gas inlet, determines a volume of forward flow and a volume of reverse flow, receives information indicative of ventilator type, determines the ventilator type based on the received information, and compensates for the flow in the reverse direction based on the ventilator type,
wherein the ventilator type is determined to be a BiPAP ventilator and/or a ventilator affiliated with single limb breathing circuit, and
wherein the therapeutic gas comprises nitric oxide.

10. The nitric oxide delivery system of claim 9 , further comprising a carbon dioxide sensor that is one or more of (i) in fluid communication with the injector module and/or a connection between the breathing circuit and a sample line and (ii) is at and/or in the injector module and/or a connection between the breathing circuit and the sample line.

11. The nitric oxide delivery system of claim 10 , wherein compensating for the flow in the reverse direction further comprises delivering therapeutic gas into the breathing circuit for the reverse flow measured that contains carbon dioxide and not delivering therapeutic gas into the breathing circuit for the reverse flow measured that does not contain carbon dioxide.

12. The nitric oxide delivery system of claim 9 , wherein when the at least one bi-directional BCG flow sensor measures flow in the reverse direction, the control valve is closed and the therapeutic gas is not delivered into the breathing circuit via the therapeutic gas inlet,
wherein when the at least one bi-directional BCG flow sensor measures flow in the forward direction after the at least one bi-directional BCG flow sensor measures flow in the reverse direction, the therapeutic gas is delivered into the breathing circuit after compensating for the flow in the reverse direction by opening the control valve after the volume of resumed forward flow is at least equal to the volume of reverse flow.

13. The nitric oxide delivery system of claim 9 , wherein compensating for the flow in the reverse direction comprises comparing the volume of the flow in the reverse direction to a dead space volume and not delivering therapeutic gas into the breathing circuit until after the volume of resumed forward flow has been measured equaling the lesser of (i) the volume of reverse flow measured or (ii) the dead space volume.

14. The nitric oxide delivery system of claim 9 , wherein information regarding the bi-directional BCG flow is used by the nitric oxide delivery system to ensure that a desired dose

Assignees

• Mallinckrodt Pharmaceuticals Ireland Ltd

Inventors

• Acker Jaron M
• Tolmie Craig R

Classifications

• A61M2205/18

  with alarm · CPC title

• A61M16/0051 Primary

  with alarm devices · CPC title

• A61M2205/3334

  Measuring or controlling the flow rate · CPC title

• A61M2016/103

  the CO2 concentration · CPC title

• A61M2016/102

  Measuring a parameter of the content of the delivered gas · CPC title