US-12623040-B2 - Nasal seal for a respiratory patient interface

US12623040B2US 12623040 B2US12623040 B2US 12623040B2US-12623040-B2

Abstract

A nasal seal for a respiratory therapy mask for contacting the face of a user. The nasal seal has a main body defining a cavity and a fluid inlet, and has two nasal prongs projecting from the main body for the delivery of fluid to the user's nares. A transition fillet is provided around a base of each prong, between the nasal prong and the main body, with each transition fillet having a constant chord length.

Inventors

Tony William Spear
Matthew Roger Stephenson

Assignees

FISHER & PAYKEL HEALTHCARE LIMITED

Dates

Publication Date: 20260512
Application Date: 20190912

Claims (20)

1 . A nasal seal for a respiratory therapy mask for contacting the face of a user, the nasal seal comprising: a main body defining a cavity and a fluid inlet; two nasal prongs projecting from the main body for the delivery of fluid to the user's nares; and a transition fillet around a base of each prong, the transition fillet defining a transition between the main body and the base of each prong, the transition fillet extending in a radially outward direction from the base of each prong between a first edge of the transition fillet at the nasal prong and a second edge of the transition fillet at the main body, the second edge positioned radially outward from the first edge, an outer surface of the transition fillet defining a concave surface in the radial outward direction extending from the first edge and the second edge; wherein the transition fillet has a chord length from the first edge to the second edge, wherein the chord length of each transition fillet is constant around the base of each prong.
2 . A nasal seal as claimed in claim 1 , wherein the nasal seal comprises a resilient material.
3 . A nasal seal as claimed in claim 1 , wherein a terminal region of each nasal prong has a wall thickness that tapers towards a tip of the nasal prong.
4 . A nasal seal as claimed in claim 3 , wherein the wall thickness at the nasal prongs' tips is less than 20% of the wall thickness of the nasal prong wall in a major part of the nasal prong.
5 . A nasal seal as claimed in claim 3 , wherein in the terminal region, the nasal prong wall thickness gradually decreases over a length of about 2 mm.
6 . A nasal seal as claimed in claim 3 , wherein, in the terminal regions, the taper has a varying chord length and a varying radius of curvature.
7 . A nasal seal as claimed in claim 3 , wherein each nasal prong defines a cavity wherein the cross sectional area of each cavity decreases from a maximum area at the base of the prong to a minimum area at the tip of the prong.
8 . A nasal seal as claimed in claim 3 , wherein each nasal prong comprises a nare sealing region between the terminal region and the base of the respective prong, the nare sealing region having a concave transition region adjacent the terminal region, the transition region having a height that is constant around a perimeter of the prong.
9 . A nasal seal as claimed in claim 3 , wherein each nasal prong comprises a nare sealing region between the terminal region and the base of the respective prong, at least a major part of the nare sealing region having a wall thickness at least twice the wall thickness of a user contacting rear part of the seal main body.
10 . A nasal seal as claimed in claim 9 , wherein a user-contacting portion of the seal main body has a wall thickness in the range of about 0.4 mm to about 0.6 mm.
11 . A nasal seal as claimed in claim 9 , wherein side walls of the seal main body have a wall thickness in the range of about 1.8 mm to about 2.2 mm.
12 . A nasal seal as claimed in claim 1 , wherein each nasal prong defines a non-cylindrical cavity.
13 . A nasal seal as claimed in claim 12 , wherein the cavity in each nasal prong has a cross-section with a major dimension and a minor dimension, both the major and minor dimensions decreasing from the base of the respective prong to the tip.
14 . A nasal seal as claimed in claim 1 , wherein the fluid inlet is a substantially D-shaped opening, being widest at a bottom of the opening and narrowest at the top of the opening.
15 . A nasal seal as claimed in claim 1 , comprising an inwardly extending lip at the fluid inlet for engaging a support frame.
16 . A nasal seal as claimed in claim 15 , wherein the lip is arcuate in side profile, and concave relative to a front of the seal.
17 . A nasal seal as claimed in claim 16 , wherein the lip side profile has a radius of about 25 mm.
18 . A nasal seal as claimed in claim 1 , wherein a radius of each transition fillet varies around the base of each prong.
19 . The nasal seal as claimed in claim 1 , wherein the transition fillet extends radially outward from the first edge.
20 . The nasal seal as claimed in claim 1 , wherein the main body comprises side walls and a concave user contacting surface, wherein the two nasal prongs project from the concave user contacting surface, wherein the transition fillet is defined between the concave user contacting surface and the base of each prong, wherein the concave user contacting surface extends towards the cavity.

Description

BACKGROUND Field of the Invention The present disclosure generally relates to a respiratory patient interface, in particular to a nasal pillow type mask. Description of the Related Art Respiratory masks are used to provide respiratory therapy to the airways of a person suffering from any of a number of respiratory illnesses or conditions. Such therapies may include but are not limited to continuous positive airway pressure (CPAP) therapy and non-invasive ventilation (NIV) therapy. CPAP therapy can be used to treat obstructive sleep apnoea (OSA), a condition in which a patient's airway intermittently collapses during sleep, preventing the patient from breathing for a period of time. The cessation of breathing, or apnoea, results in the patient awakening. Repetitive and frequent apnoeas may result in the patient rarely achieving a full and restorative night's sleep. CPAP therapy involves the delivery of a supply of continuous positive air pressure to the airway of the patient via a respiratory mask. The continuous positive pressure acts to keep the airway in an open position so the patient's breathing and sleep are not interrupted. CPAP therapy requires the user to wear a respiratory interface which seals against a user's face, around their nose and/or mouth via a seal/cushion to deliver respiratory gas or gases such as air to a user under positive pressure. Respiratory masks are available in a range of styles including full-face, nasal, direct nasal and oral masks. The seal/cushion is held in place on the user's face by headgear which provides support to the respiratory interface such that it is held in a stable position relative to the user's face during use. Such respiratory masks may also be used to deliver NIV and other therapies. Patients may be deterred from using CPAP therapy if they find the respiratory interface uncomfortable or invasive or if they find the appearance of the interface unattractive. There is a desire for more discrete, compact user interfaces. During the treatment of OSA, a patient wears the mask while they sleep, so the mask must fit with enough stability to not be dislodged as the patient turns in their sleep. CPAP therapy is commonly used in a home environment, on occasion it is necessary to change the seal of the respiratory interface, either for replacement or cleaning. For users with impaired motor function, changing a seal, or refitting the seal if it becomes separated from the supporting frame, can be difficult. Often this requires precision handling, and may involve non-intuitive assembly steps and/or the use of separate connector components. Handling the seal in this manner, or indeed day to day handling, can cause portions of the seal to become inverted or rolled over on themselves, for example nasal prongs in a nasal seal may roll or ‘pop’ inwards. This same inversion of components may occur during use of the mask, for example by incorrectly fitting the mask, or through movement of the mask. Righting these inverted components can be challenging for some users, particularly for those users with impaired motor skills or vision. In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally to provide a context for discussing features of the invention. Unless specifically stated otherwise, reference to such external documents or sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art. SUMMARY OF THE INVENTION In a first aspect, the present disclosure relates to a nasal seal for a respiratory therapy mask for contacting the face of a user. The nasal seal has a main body defining at least a portion of a cavity and a fluid inlet, two nasal prongs projecting from the main body for the delivery of fluid to the user's nares, and a transition fillet around a base of each prong, between the nasal prong and the main body. The cavity forms a breathing chamber. Each transition fillet has a constant chord length. In an embodiment, the nasal seal comprises a resilient material. For example, the nasal seal may include an elastomer such as silicone. In one embodiment, the nasal seal comprises a single-durometer silicone. In an embodiment, a terminal region of each nasal prong has a wall thickness that tapers towards a tip of the nasal prong. The wall thickness at the nasal prongs' tips may be less than 20% of the wall thickness of the nasal prong wall in a major part of the nasal prong. In an embodiment, the nasal prong wall thickness gradually decreases over a length of about 2 mm. That is, the terminal region of the prong is 2 mm in length. In alternative embodiments the terminal region may be longer or slightly shorter, and is preferably in the range of about 1.2 mm to about 4 mm, more preferably about 1.6 mm to about 3 mm, and most preferably in the