WO2022266435A1

WO2022266435A1 - Nape strap

Info

Publication number: WO2022266435A1
Application number: PCT/US2022/033980
Authority: WO
Inventors: David M. Kane; Ryan REDFORD; Steve CATALDO
Original assignee: Pneuma Therapeutics Inc
Current assignee: Pneuma Therapeutics Inc
Priority date: 2021-06-17
Filing date: 2022-06-17
Publication date: 2022-12-22
Anticipated expiration: 2023-12-17

Abstract

A strap assembly for a face mask includes a nape strap, a bridge strap, and a load transmission strap(s). The nape strap that lays nominally along the X - Y plane, running behind the nape of the patient's neck and attaches to the + X and -X face of the nasal respiratory mask by being inserted through a loop slot on each side of the nasal respiratory mask. The bridge strap passes over a patient's head and attaches to the nape strap at the back of the patients neck.

Description

NAPE STRAP BACKGROUND Field [0001] Embodiments of the present invention relate to nape strap for use with a face mask, specifically a respiratory mask for use with respiratory systems. Background [0002] FIG. 1A illustrates a crown-centered strap 100 in conjunction with an exemplary nasal respiratory device 104. FIG. 1B illustrates the crown- centered strap 100 of FIG. 1A in conjunction with an exemplary nasal respiratory circuit, which may include, for example, a nasal respiratory device 10 and ventilation bag 112, manual resuscitator, or a continuous or intelligently-controlled gas supply (not shown). The device may include end-tidal sampling 116 and/or instrumentation. [0003] In the strap 100 illustrated in FIGs. 1A and 1B, it is possible that if a load, F_Circuit, is applied by an attached respiratory circuit in the -Z direction, a negative moment about the X axis results, potentially separating the nasal respiratory mask from the nasal base and breaking the seal, disrupting flow of respiratory gasses to the patient and impacting instrumentation or appropriate measuring of conditions, such as end-tidal gasses. [0004] Accordingly, an improvement to reduce the likelihood of the breaking of the seal and disrupting the flow of respiratory gasses to the patient would be beneficial. BRIEF SUMMARY OF THE DISCLOSURE [0005] Accordingly, the present invention is directed to strap for use with nasal respiratory or other devices that obviates one or more of the problems due to limitations and disadvantages of the related art. [0006] In accordance with the purpose(s) of this disclosure, as embodied and broadly described herein, this disclosure, in one aspect, relates to a strap having a nape strap, that, when worn, passes behind the neck of a patient and lies nominally along and X – Y plane, running behind a nape of a patient’s neck and attaches to the + X and -X face of the face mask. The strap assembly may further include a bridge strap that lies nominally along the Y-Z plane over a nasal bridge of the patient and attaches to the nape strap. [0007] In another aspect, the disclosure relates a method for applying a face mask with the strap assembly to a person’s face. [0008] Additional advantages of the devices and methods described herein will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of any invention, as claimed. [0009] Further embodiments, features, and advantages of the nape strap as well as the structure and operation of the various embodiments of the nape strap, are described in detail below with reference to the accompanying drawings. [0010] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The accompanying figures, which are incorporated herein and form part of the specification, illustrate a nape strap according to principles described herein. Together with the description, the figures further serve to explain the principles of the nape strap described herein and thereby enable a person skilled in the pertinent art to make and use the nape strap. [0012] FIG. 1A illustrates a crown-centered strap in conjunction with an exemplary nasal respiratory device. [0013] FIG. 1B illustrates the crown-centered strap of FIG. 1A in conjunction with an exemplary nasal respiratory. [0014] FIGs. 2A, 2B, 2C, and 2D illustrate an example of a nape strap according to principles described herein. [0015] FIGs. 3A, 3B and 3C illustrate a head strap as described herein in combination with an example nasal respiratory device and/or respiratory circuit. [0016] FIGs. 4A, 4B, 4C and 4D illustrate a nape strap according to principles described herein in combination with an example nasal respiratory device and/or respiratory circuit. [0017] FIG. 5 illustrates connectors for use with a nape strap according to principles described herein. DETAILED DESCRIPTION [0018] Reference will now be made in detail to embodiments of the nape with reference to the accompanying figures The same reference numbers in different drawings may identify the same or similar elements. [0019] Reference will now be made in detail to embodiments of a head strap for use with a face mask, in particular, a respiratory mask, with reference to the accompanying figures. [0020] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. [0021] Although illustrated here with respect to a nasal respiratory mask dubbed the XChange™ device, the strap is not so limited and may be used with any face mask, but is considered to be well-suited to respiratory masks and particularly nasal respiratory masks because of the benefits of the seal created by the mask and the adjustable features of the disclosed strap embodiments that allow for various forces, as described, to be applied to suitably maintain and/or adjust the seal between the mask and a wearer’s face. [0022] A nasal respiratory mask/device (such as the XChange™ device shown in the figures) with a crown-centered head strap 100 configuration and cartesian coordinate system are illustrated in FIGS. 1A and 1B. The views of FIGs. 1A and 1B show a right strap 120 (on the right side of the patient’s head 101), and a complementary left strap (on the left side of the patient’s head) is not shown. [0023] The head strap 100 to a +X and -X face 124 of the nasal respiratory mask 104 is at an angle θ relative to the Y axis centered over the crown of the head 101. When worn by a patient 101, the left strap and the right strap 120 are under tension, each providing a force F_Strap. This force seals the nasal respiratory mask 104 against the nasal base (not shown) through the resultant force F_Z reacting against the nasal base, nominally a distance L from the X axis, and F_Y reacting against the philtrum, nominally a distance l from the X axis. The force relationship is governed by the following equations: F_Strap = Strap tension force θ = angle between F_Strap and Y axis = nominally 30 – 45 degrees F_Z = Strap force in the +Z direction = FStrap sin( θ) FY = Strap force in the -Y direction = -F_Strap cos( θ) [0024] In the strap 100 configuration illustrated in FIGs. 1A and 1B, it is possible that if a load, F_Circuit, is applied by an attached respiratory circuit 108 in the -Z direction, a negative moment about the X axis results, potentially separating the nasal respiratory mask 104 from the nasal base and breaking the fluidic/gas seal that causes flow of the gas from the gas supply to be supplied to the nostrils of the patient. [0025] Referring to FIGs. 3A-3C, the moment about the X axis is described by the formulas below: F_Circuit = Applied circuit load in the -Z direction L_Circuit = distance from X axis to applied circuit load = approximately 40 mm L ≈ 15 mm MX = moment about the X axis due to forces along the Z axis = F_Z x L– F_Circuit x L_Circuit [0026] If the net moment about the X axis, MX, is negative, the nasal respiratory mask may rotate away from the nasal base and the seal will be broken. Given L_Circuit is approximately 2.7 x L, if F_Circuit is > 1/2.7 (-F_Z), the seal will break. [0027] To reduce the likelihood that a circuit load in the negative Z direction will break the seal, a new strap design is shown in FIGs. 2A-2D. The illustrated strap assembly 203 includes a Nape Strap 228, a bridge strap 234 and a load transmission strap(s) 238. The nape strap 200 that lays nominally along the X – Y plane, running behind the nape of the patient’s neck 205 and attaches to the + X and - X face of the nasal respiratory mask (not shown) by being inserted through a loop slot on each side of the nasal respiratory mask. [0028] FIGs. 2A and 2B illustrate a perspective view of a nape strap 200 as worn by a patient 101 according to principles described herein. The nape strap 228 may be attached to the respiratory device 104 via slots and/or rings 240, and folded back over on itself, attaching with hook and loop material (not shown), as illustrated in FIGs. 2A and 2B. In an alternative aspect, the nape strap 228 may connect back to itself via an adhesive, which may be removable/repositionable. [0029] FIG. 2D illustrates an example attachment of a bridge strap according to principles described herein. The Bridge Strap 234 lies nominally along the Y-Z plane. The bridge strap 234 attaches to the respiratory device 104, for example, to the gas port 207 via a Device-Bridge Strap Slot interface 250. As illustrated in FIG. 2D, the strap slot interface 250 may be a hook 246 that hooks around a profile/circumference the gas port 207. The hook 246 may be further secured to the gas port by a latch or hook (not shown). In another embodiment, a slot or other attachment mechanism may be mounted on the nasal respiratory device 104 or the gas port 207 for receiving the hook 246 or other attachment mechanism on the bridge strap 234. [0030] For example, the bridge strap 234 may attach to the gas port 207 of the nasal respiratory mask 104 with a strap ring 248 that includes the Device- Bridge Strap Slot interface shown in FIGs. 4A-C. The strap ring 248 slides over the gas port and the Bridge strap 234 is inserted through the slot 242 and over on itself, attaching with hook and loop material. In an alternative aspect, the strap 234 may connect back to itself via an adhesive, which may be removable/repositionable. [0031] These alternate configurations also illustrated in FIG. 5, where the C ring 246 snaps onto the side of the gas port along the X – Z plane. Additionally, a Device-Bridge Strap Slot interface that is integral with the gas port of the nasal respiratory mask is possible. In another embodiment, a slot or other attachment mechanism may be mounted on the nasal respiratory device body or the gas port for receiving the hook or other attachment mechanism on the bridge strap. [0032] Referring again to FIGs. 2A-D and 4A-D, the bridge strap passes from the respiratory device 104 over the top of the patient’s head to the back of the patient’s head, where the bridge strap 234 connects to a load transmission strap 238 that extends to the nape strap 228 that extends from the respiratory device 104 and around the nape 205 of the patient. [0033] FIGs. 2C and 4D illustrate a rear view of a nape strap 228 as worn by a patient 101 according to principles described herein. As illustrated, the load transmission strap may include two straps 238a and 238b extending from an interface with the bridge strap 234 to the nape strap 228 at the nape 205 of the patient. The interface 254 of the bridge strap 234 with the load transmission strap 238 could be an integral (e.g., woven) interface. The two straps 238a and 238b may extend from the interface with the bridge strap 254 separated by an angle, which may be, for example 0-90 degrees, but is not so limited. [0034] As illustrated in FIG. 4D, tension force F_Bridge of the bridge strap 234 is countered by force F_Reaction of the load transmission strap 238. [0035] The force relationship for the configuration illustrated in FIGs. 4A-C is governed by the following equations: F_Bridge = Bridge Strap tension force θ = angle between the bridge strap (F_Strap)and Y axis = nominally 70 - 80 degrees F_Z = Bridge Strap force in the +Z direction = F_Bridge sin(q) F_Nape = Nape Strap tension force ( θ_N) = Nape Strap angle relative to the Y axis = Nominally 0 – 10 Degrees F_Y = Nape Strap force in the -Y direction = - F_Nape cos(qN) [0036] The moment about the X axis for the Nape / Bridge strap configuration is described by the formulas below: F_Circuit = Applied circuit load in the -Z direction L_Circuit = distance from X axis to applied circuit load = approximately 40 mm L ≈ 35 mm M_X = moment about the X axis due to forces along the Z axis = F_Z x L– F_Circuit x L_Circuit [0037] Advantages of the Nape / Bridge Strap configuration when compared to the Crown-Centered Head Strap configuration in terms of the net moment about the X axis and maintaining a nasal seal include that the strap angle, θ, of, e.g., 70 – 80 degrees results in F_Z that is up to 98% of F_Bridge, versus 70% for the other design due to the larger angle; that the moment arm for F_Z is almost the same as that of the gas circuit, 35 mm versus 40 mm, since both attach/interface at the gas port of the nasal respiratory mask; and that the tension of the Bridge Strap can be adjusted independently of the Nape strap, since the two are nominally decoupled. This makes it easier for a clinician to increase the strap tension to maintain the seal if needed. [0038] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS: 1. A strap assembly for a face mask comprising a nape strap that lies nominally along the X – Y plane, for running behind a nape of a patient’s neck and attaching to the + X and -X face of the face mask.

2. The strap assembly of claim 1, further comprising a bridge strap that lies nominally along the Y-Z plane over a nasal bridge of the patient and attaches to the nape strap.

3. The strap assembly of claim 2, wherein face mask is a respiratory mask and the bridge strap attaches to a gas port of the respiratory mask.

4. The strap assembly of claim 2 or claim 3, wherein the bridge strap which attaches via a load transmission strap, which extends from the bridge strap to the nape strap.

5. The strap assembly of any one of claims 2-4, wherein the bridge strap, when worn by the patient, runs along the bridge of the nose, over the forehead, over the crown of the patient to the nape strap.

6. The strap assembly of any one of claims 2-5, further comprising a slot interface for attaching the bridge strap to the face mask.

7. The strap assembly of claim 6, wherein the slot interface comprises a strap ring, that slides over a gas port of the face mask, wherein the bridge strap is inserted through the slot and over on itself, attaching with hook and loop material or other suitable attachment mechanism, including but not limited to clips, adhesive, snaps, and the like.

8. The strap assembly of claim 6, wherein the slot interface comprises a C ring that snaps onto a side of a gas port of the face mask along the X – Z plane.

9. The strap assembly of claim 6, wherein slot interface is integral with the face mask on or near a gas port.

10. The strap assembly according to any of the preceding claims, wherein the face mask is a nasal respiratory mask according to WO/2020132664.

11. The strap assembly according to any of the preceding claims, wherein the nape strap is connected to the mask via slots and folded onto itself and secured via an attachment mechanism, including but not limited to hook and look material, clips, adhesive, snaps, and the like.

12. The strap assembly according to any of the preceding claims above, wherein the bridge strap is connected to the mask via slots and folded onto itself and secured via an attachment mechanism, including but not limited to hook and look material, clips, adhesive, snaps, and the like.

13. The strap assembly according to any of the preceding claims, having a force relationship according to: F_Bridge = Bridge Strap tension force θ = angle between F_Strap and Y axis = nominally 70 - 80 degrees F_Z = Bridge Strap force in the +Z direction = F_Bridge sin( θ) F_Nape = Nape Strap tension force ( θ_N) = Nape Strap angle relative to the Y axis = Nominally 0 – 10 Degrees F_Y = Nape Strap force in the -Y direction = -F_Nape cos( θ_N) 14. A method of applying the strap assembly of any of the preceding claims to a wearer. 15. A method of applying a face mask to a person’s face a strap according to any of the preceding claims, by applying the nape strap of the strap assembly behind the neck of the person and attaching it to a face or faces of the face mask;and applying a bridge strap from the rear of the person’s head to a face of the face mask at the front of the person’s head. 16. The method of claim 15, wherein the bridge strap at the rear of the person’s head comprises two connector straps that are connected to the nape strap at the rear of the person’s head or neck, or the bridge strap at the rear of the person’s head comprises a single strap connects to the nape strap at a rear of the person’s head or neck. 17. The method any one of claims 15-16, wherein the nape strap is connected to the mask via slots and folded onto itself and secured via an attachment mechanism, including but not limited to hook and look material, clips, adhesive, snaps, and the like. 18. The method any one of claims 15-17, wherein the bridge strap is connected to the mask via slots and folded onto itself and secured via an attachment mechanism, including but not limited to hook and look material, clips, adhesive, snaps, and the like. 19. A kit comprising the strap assembly of any one of claims 1-10 and a face mask. 20. The kit of claim 19, wherein the face mask is a nasal respiratory mask.