Systems and methods for managing pressure in a breathing assistance system

• US 8,181,648 B2
• Filed: 09/26/2008
• Issued: 05/22/2012
• Est. Priority Date: 09/26/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Perine, Philippe, Gentner, Julien, Desfossez, Benjamin, Nicolazzi, Pascal, Gaudard, Yves, Nadjafizadeh, Hossein
• Primary Examiner(s): Yu, Justine
• Assistant Examiner(s): Skorupa, Valerie L
• Application Number:
  US12/238,607
• Publication Number:
  US 20100078023A1
• Time in Patent Office: 1,334 Days
• Field of Search: 128/200.24, 128/204.18, 12820421-20423, 128/204.26, 128/205.23, 73/15.7
• US Class Current: 128/204.18
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0816 Joints or connectors
• CPC Class Codes: A61M 16/085 Gas sampling
• CPC Class Codes: A61M 16/10 Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/003 with a flowmeter
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches

Abstract

A breathing assistance system for providing breathing assistance to a patient is provided. The breathing assistance system may include a ventilation system for supplying a gas flow, a conduit operatively coupled to the ventilation system, and a pressure sensor configured to measure the pressure of the gas flow through the conduit. The pressure sensor may include a structure configured to create a localized pressure drop in the gas flow proximate the pressure sensor structure.

Claims

1. A breathing assistance system for providing breathing assistance to a patient, comprising:

a ventilation system for supplying a gas flow to the patient;

a conduit operatively coupled to the ventilation system; and

a pressure sensor located on or in the conduit and spaced apart from the patient;

wherein the pressure sensor is configured to measure the pressure of the gas flow through the conduit, the pressure sensor including a structure configured to create a localized pressure drop in the gas flow that compensates for an inherent pressure drop in the gas flow related to the distance between the pressure sensor and the patient and unrelated to the pressure sensor, such that the pressure measured by the pressure sensor spaced apart from the patient approximates the actual pressure of the gas flow at the patient.

2. A breathing system according to claim 1, wherein the pressure sensor structure extends at least partially into an interior of the conduit.

3. A breathing system according to claim 1, wherein:

gas flows through the conduit in a first direction from an upstream location to a downstream location during positive gas flow toward a patient; and

the pressure sensor structure defines an inlet side facing the downstream location, and a gas inlet formed in the inlet side, the gas inlet configured to receive gas for pressure measurement.

4. A breathing system according to claim 1, wherein:

gas flows through the conduit in a first direction from an upstream location to a downstream location during positive gas flow toward a patient; and

the pressure sensor structure defines a leading side facing the upstream location, the leading side configured to produce a localized pressure drop in the gas flow as gas flows around the leading side.

5. A breathing system according to claim 1, wherein:

gas flows through the conduit in a first direction from an upstream location to a downstream location during positive gas flow toward a patient; and

the pressure sensor structure defines a gas inlet aligned generally parallel with the first direction of gas flow.

6. A breathing system according to claim 1, wherein a portion of the pressure sensor structure extending into the conduit includes a substantially triangular or substantially T-shaped cross section.

7. A breathing system according to claim 1, wherein:

gas flows through the conduit in a first direction from an upstream location to a downstream location during positive gas flow toward a patient; and

the pressure sensor structure defines;

a leading side facing the upstream location and configured to affect the gas flow as the gas flow encounters the pressure sensor structure; and

an inlet side facing the downstream location, the inlet side having a substantially flat structure and having a gas inlet formed therein for receiving gas to be measured.

8. A breathing system according to claim 1, further comprising a controller configured to:

receive pressure measurement signals from the pressure sensor;

compare the received pressure measurement signals to a target pressure value; and

control the gas delivery device based at least on the results of the comparison of the received pressure measurement signals to the target pressure value.

9. A pressure sensor for use in a breathing assistance system for providing breathing assistance to a patient comprising:

a pressure sensor structure extending at least partially into an interior of a conduit operatively coupled to a ventilation system configured to supply a gas flow to a patient;

wherein the pressure sensor is spaced apart from the patient;

wherein the pressure sensor structure is configured to affect the gas flow in the conduit to create a localized pressure drop that compensates for an inherent pressure drop in the gas flow related to the distance between the pressure sensor and the patient and unrelated to the pressure sensor, such that the pressure measured by the pressure sensor spaced apart from the patient approximates the actual pressure of the gas flow at the patient; and

a gas inlet formed in the pressure sensor structure, the gas inlet configured to receive gas for pressure measurement.

10. A pressure sensor according to claim 9, wherein the gas inlet is formed in an inlet side of the pressure sensor structure configured to face a downstream end of the conduit during positive flow toward the patient.

11. A pressure sensor according to claim 9, wherein the pressure sensor structure defines a leading side configured to face an upstream end of the conduit during positive flow toward the patient, the leading side configured to substantially produce the localized pressure drop in the gas flow as gas flows around the leading side.

12. A pressure sensor according to claim 9, wherein the gas inlet is aligned generally parallel with a direction of gas flow through the conduit from an upstream location to a downstream location.

13. A pressure sensor according to claim 9, wherein a portion of the pressure sensor structure extending into the conduit includes a substantially triangular or substantially T-shaped cross section.

14. A pressure sensor according to claim 9, wherein the pressure sensor structure defines:

a leading side facing an upstream end of the conduit and configured to affect the gas flow as the gas flow encounters the pressure sensor structure; and

an inlet side facing a downstream end of the conduit, the inlet side having a substantially flat structure having the gas inlet formed therein.

15. A method for controlling pressure delivered to a patient of a breathing assistance system, comprising:

determining a target pressure setting;

controlling a gas delivery device to generate a gas flow to a patient, the gas flow based at least on the target pressure setting;

receiving pressure measurements from a pressure sensor operatively coupled to a conduit coupled to the gas delivery device, the pressure sensor being spaced apart from the patient and including a structure configured to create a localized pressure drop in the gas flow that compensates for an inherent pressure drop in the gas flow related to the distance between the pressure sensor and the patient and unrelated to the pressure sensor, such that the pressure measured by the pressure sensor spaced apart from the patient approximates the actual pressure of the gas flow at the patient; and

adjusting the gas delivery device based at least on the pressure measurements received from the pressure sensor.

16. A method according to claim 15, further comprising:

comparing one or more pressure measurements received from the pressure sensor to the target pressure setting; and

adjusting the gas delivery device based at least on the comparison between the one or more pressure measurements received from the pressure sensor and the target pressure setting.

17. A method according to claim 15, wherein:

the gas flow generated by the gas delivery device flows through the conduit in a first direction from an upstream location to a downstream location during positive gas flow toward the patient; and

the pressure sensor structure defines a gas inlet formed in an inlet side facing the downstream location, the gas inlet configured to receive gas for pressure measurement.

18. A method according to claim 17, wherein the gas inlet is aligned generally parallel with the first direction of gas flow through the conduit from the upstream location to the downstream location.