US-12616810-B2 - Accurate pressure measurement with non-invasive ventilation nasal pillows

Abstract

A patient ventilation interface has a throat body defining a venturi throat that is open to ambient air, a nasal pillow disposed around the venturi throat to define a plenum between the venturi throat and the nasal pillow, a jet nozzle arranged to output ventilation gas into the venturi throat, and a pressure sensing tube having a pressure sensing port positioned to be in fluid communication with the plenum. The nasal pillow may be an integral part of the throat body. An expected error in the sensed patient airway pressure P sense may be corrected by applying a correction factor P delta indexed by the sensed patient airway pressure P sense and a jet nozzle flow V′ n of the jet nozzle. Delivery of the ventilation gas output by the jet nozzle may be controlled in response to the corrected patient airway pressure.

Inventors

• Gary John Latorraca
• Tom Westfall
• Simon Jung

Assignees

• HILL-ROM SERVICES PTE. LTD.

Dates

Publication Date

20260505

Application Date

20220404

Claims (20)

1. 1 . A patient ventilation interface comprising: a throat body defining a venturi throat that is open to ambient air; a nasal pillow disposed around the venturi throat to define a plenum between the venturi throat and the nasal pillow; a jet nozzle arranged to output ventilation gas into the venturi throat; and a pressure sensing tube having a pressure sensing port positioned to be in fluid communication with the plenum.
2. 2 . The patient ventilation interface of claim 1 , wherein the nasal pillow is an integral part of the throat body.
3. 3 . The patient ventilation interface of claim 1 , wherein the throat body has greater rigidity than the nasal pillow.
4. 4 . The patient ventilation interface of claim 1 , wherein the plenum has a crescent-shaped cross-section.
5. 5 . The patient ventilation interface of claim 1 , wherein the venturi throat tapers outwardly away from the jet nozzle.
6. 6 . The patient ventilation interface of claim 1 , further comprising a ventilation gas tube terminating in the jet nozzle, wherein at least a part of the pressure sensing tube is disposed within the ventilation gas tube.
7. 7 . The patient ventilation interface of claim 6 , wherein the pressure sensing tube extends from the ventilation gas tube into the throat body to position the pressure sensing port in fluid communication with the plenum.
8. 8 . The patient ventilation interface of claim 7 , wherein the pressure sensing port of the pressure sensing tube is in fluid communication with the plenum via a pressure sensing passage defined by the throat body.
9. 9 . The patient ventilation interface of claim 1 , further comprising an entry piece defining a venturi inlet that is in fluid communication with the venturi throat, wherein the jet nozzle is arranged to output the ventilation gas into the venturi throat via the venturi inlet.
10. 10 . The patient ventilation interface of claim 9 , wherein the entry piece defines one or more entrainment openings by which the venturi throat is open to ambient air.
11. 11 . The patient ventilation interface of claim 10 , wherein the jet nozzle is arranged to output the ventilation gas into the venturi inlet via an entrainment opening from among the one or more entrainment openings.
12. 12 . The patient ventilation interface of claim 11 , wherein the venturi inlet flares outward relative to the venturi throat.
13. 13 . A non-invasive ventilation system comprising: the patient ventilation interface of claim 1 ; and a pressure sensor fluidly coupled to the pressure sensing tube.
14. 14 . The non-invasive ventilation system of claim 13 , further comprising a controller programmed to control delivery of the ventilation gas output by the jet nozzle in response to a patient airway pressure P sense sensed by the pressure sensor.
15. 15 . The non-invasive ventilation system of claim 14 , wherein the controller is programmed to correct for an expected error in the sensed patient airway pressure P sense .
16. 16 . The non-invasive ventilation system of claim 15 , wherein the controller is programmed to correct for the expected error by applying a correction factor P delta indexed by the sensed patient airway pressure P sense .
17. 17 . The non-invasive ventilation system of claim 16 , wherein the correction factor P delta is further indexed by a jet nozzle flow V′ n of the jet nozzle.
18. 18 . The non-invasive ventilation system of claim 13 , further comprising a non-transitory program storage medium on which are stored instructions, executable by a processor or a programable circuit, to correct for an expected error in the sensed patient airway pressure P sense.
19. 19 . The non-invasive ventilation system of claim 18 , wherein the instructions are executable by the processor or the programmable circuit to correct for the expected error by applying a correction factor P delta indexed by the sensed patient airway pressure P sense.
20. 20 . The non-invasive ventilation system of claim 19 , wherein the correction factor P delta is further indexed by a jet nozzle flow V′ n of the jet nozzle.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to U.S. Provisional Application Ser. No. 63/177,533, filed Apr. 21, 2021, and U.S. Provisional Application Ser. No. 63/310,223, filed Feb. 15, 2022, the disclosures of both of which are incorporated by reference herein. STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT Not Applicable BACKGROUND 1. Technical Field The present disclosure relates generally to devices and methods for the administration of non-invasive ventilation (NIV) therapy and, more particularly, to an improved nasal pillows patient ventilation interface having integrated pressure sensing functionality adapted to be less susceptible to error attributable to increases in flow velocity. 2. Description of the Related Art For administering non-invasive ventilation (NIV) to patients having chronic obstructive pulmonary disease (COPD) or other respiratory conditions, patient comfort may best be achieved with a physically small nasal pillows interface. Unlike larger assemblies such as nasal masks or full-face masks, nasal pillows are primarily confined to the space within and immediately below the patient's nares or nostrils and do not significantly encumber the patient's face. By the same token, given that knowledge of the actual pressure in the patient's airway is important for proper NIV function as well as for compliance with international standards for medical devices, it would be beneficial for pressure sensing to be integrated into the confines of nasal pillows in order to minimize the overall encumbrance of the interface. However, nasal pillows present significant hurdles when it comes to integrating pressure sensing functionality. In general, due to Bernoulli's principle, sensing pressure in a region where air is flowing is susceptible to error as flow velocity increases. The problem becomes profound when accurate pressure measurement is attempted within the small volume described by nasal pillows. The present disclosure contemplates various systems and methods for overcoming the above drawbacks accompanying the related art. BRIEF SUMMARY One aspect of the embodiments of the present disclosure is a patient ventilation interface, such as a nasal pillows interface. The patient ventilation interface may comprise a throat body defining a venturi throat that is open to ambient air, a nasal pillow disposed around the venturi throat to define a plenum between the venturi throat and the nasal pillow, a jet nozzle arranged to output ventilation gas into the venturi throat, and a pressure sensing tube having a pressure sensing port positioned to be in fluid communication with the plenum. The nasal pillow may be an integral part of the throat body. The plenum may have a crescent-shaped cross-section. The venturi throat may taper outwardly away from the jet nozzle. The throat body may have greater rigidity than the nasal pillow. An outer surface of the throat body may be splined. The patient ventilation interface may comprise a ventilation gas tube terminating in the jet nozzle. At least a part of the pressure sensing tube may be disposed within the ventilation gas tube. The pressure sensing tube may extend from the ventilation gas tube into the throat body to position the pressure sensing port in fluid communication with the plenum. The pressure sensing port of the pressure sensing tube may be in fluid communication with the plenum via a pressure sensing passage defined by the throat body. Another aspect of the embodiments of the present disclosure is a patient ventilation interface which may comprise a throat body defining a venturi throat that is open to ambient air, a nasal pillow disposed around the throat body to define an annular plenum between the throat body and the nasal pillow, a jet nozzle arranged to output ventilation gas into the venturi throat, and a pressure sensing tube having a pressure sensing port positioned to be in fluid communication with the annular plenum. The throat body may have greater rigidity than the nasal pillow. An outer surface of the throat body may be splined. The patient ventilation interface may comprise a ventilation gas tube terminating in the jet nozzle. At least a part of the pressure sensing tube may be disposed within the ventilation gas tube. The pressure sensing tube may extend from the ventilation gas tube into the nasal pillow to position the pressure sensing port in fluid communication with the annular plenum. The pressure sensing port of the pressure sensing tube may be in fluid communication with the annular plenum via a pressure sensing passage defined by the nasal pillow. Another aspect of the embodiments of the present disclosure is a patient ventilation interface which may comprise a nasal pillow body defining a venturi throat that is open to ambient air and having a nasal pillow portion disposed around the venturi throat to define a plenum within the nasal pillow body and outside the venturi throat. The patient