Gel filling for a patient interface and method for producing a patient interface with a gel filling

Abstract

The invention concerns a gel covering of a patient interface. This gel covering has a mask connection area by which its side that faces away from the patient is joined with a mask body. The patient interface can be designed, for example, as a respiratory mask. On its side that faces the patient's face, the respiratory mask has thin, inwardly formed, peripheral contact lips. The respiratory mask has accessories that allow it to be fastened on the patient's head as well as a hose connection for supplying air. At least one region formed from a filler is placed in or on the walls of the gel covering. The method is used to produce the gel covering of the invention.

Claims

1. A method for producing a patient interface for resting on an outer surface of a patient's body and containing a gel filling, wherein a gel covering formed from a flexible material has a cavity at least in some areas and has at least one dedicated opening through which the cavity is filled with gel in liquid form, which then cures in the gel covering to a hardness, at least in some areas, of from about 10 Shore OO to about 30 Shore OO, the opening being situated in the gel covering in areas that do not come into contact with the patient's skin.

2. The method of claim 1, wherein an opening in the gel covering is sealed with a stopper.

3. The method of claim 2, wherein adhesive is used to join the gel covering and the stopper.

4. The method of claim 2, wherein the stopper is made of silicone.

5. The method of claim 1, wherein the opening is produced in the gel covering by puncturing it with an injection device and the gel covering is filled with liquid gel by the injection device.

6. The method of claim 1, wherein an opening in the gel covering is sealed by cured gel.

7. The method of claim 1, wherein the gel covering is made of silicone.

8. The method of claim 1, wherein the gel is a silicone gel.

9. The method of claim 8, wherein the silicone gel has a silicone oil fraction of less than 20%.

10. The method of claim 8, wherein the silicone gel contains no silicone oil.

11. The method of claim 1, wherein the cured gel has a hardness, at least in some areas, of from about 12 Shore OO to about 20 Shore OO.

12. The method of claim 1, wherein the covering is produced by filling a covering blank with gel and sealing an opening in the covering by a stopper, wherein a permanent connection between the covering blank and the stopper is produced by the use of a joining element, and wherein the sealed covering is produced from a uniform material, the opening being provided in an area of a connecting member, which connecting member terminates walls of the gel covering on a patient interface side.

13. The method of claim 12, wherein the uniform material is silicone.

14. The method of claim 12, wherein the joining element is liquid silicone.

15. The method of claim 12, wherein the joining element is activated by action of energy.

16. The method of claim 1, wherein the gel filling has a cross section of less than 5 mm.

17. The method of claim 1, wherein the gel covering has a wall thickness, at least in some areas, of about 0.5 mm.

18. The method of claim 1, wherein the gel covering has a wall thickness, at least in some areas, of less than 0.3 mm.

19. The method of claim 1, wherein the patient interface is for use with a nasal pillow.

20. The method of claim 1, wherein the patient interface is adapted for resting on a patient's face.

21. The method of claim 1, wherein the patient interface is for use with a face mask.

22. The method of claim 1, wherein the patient interface is for use with an oral mask.

23. The method of claim 1, wherein the patient interface is for use with a medical orthose.

24. The method of claim 1, wherein the patient interface is for use with a medical prosthesis.

Description

(1) Details of the present invention will now be described on the basis of the specific embodiments illustrated in the accompanying drawings, in which functionally equivalent parts are referred to with corresponding reference numbers.

(2) FIG. 1 shows a perspective view of a patient interface in the form of a nasal mask,

(3) FIG. 2 shows a perspective view of an embodiment of the gel covering,

(4) FIG. 3 shows the embodiment of the gel covering in FIG. 2 from below,

(5) FIG. 4 shows a side view of the embodiment of the gel covering in FIG. 2,

(6) FIGS. 5 to 8 each show a cross section through the gel covering,

(7) FIG. 9 shows a cross section through the gel covering and the patient interface in the contact area,

(8) FIG. 10 shows a cross section through the gel covering and the patient interface in the contact area with mechanical locking,

(9) FIG. 11 shows a cross section through the gel covering and the patient interface with a second cover,

(10) FIG. 12 shows a cross section through the gel covering and the patient interface in the contact area with a sealing element,

(11) FIG. 13 shows five variants of possible means of connection,

(12) FIG. 14 is a schematic representation of injection molding with several components,

(13) FIG. 15 is a sketch illustrating a production process,

(14) FIG. 16 shows a injection molding process with the use of a transfer plate,

(15) FIG. 17 is another drawing that illustrates the injection molding process,

(16) FIG. 18 shows a perspective view and two sectional views of a nasal pillow,

(17) FIG. 19 shows a side view of and a longitudinal section through a nasal pillow,

(18) FIG. 20 shows an embodiment of a nasal pillow from FIG. 19,

(19) FIG. 21 shows an embodiment of a two-part nasal pillow,

(20) FIG. 22 shows a nasal pillow with two membrane openings, and

(21) FIG. 23 shows a modification of FIG. 23.

(22) FIG. 1 shows a patient interface in the form of a nasal mask, whose mask body 1 is made of a relatively strong material and which has a gel-filled covering 3. This covering 3 is the part of the mask that rests on a patient's face (not shown) and provides the necessary seal. The mask body 1 is connected by an angled connector 2 to a sleeve 4, which is rotatably supported and serves to connect the mask to a respiratory gas hose (not shown). To guarantee secure positioning of the respiratory mask on a patient's head, a forehead support 5 is used, which has a shaft 35 that is inserted in a mount 36 of the mask body 1. The connector 2 and the mask body 1 are connected by a ball-and-socket joint 18. The ball-and-socket joint 18 is supported by a retaining ring 31. A forehead pad 13 is fastened on a mount 12 of the forehead support in a way that allows it to slide. The forehead pad 13 provides additional support for the mask on the forehead of the patient. The mask is fastened on the patient's head with straps (not shown).

(23) On its contact side intended for contact with the patient's face, the gel covering 3 ends in a contact lip 7 that becomes thinner and thinner and provides the gel covering 3 with a soft and flexible contact zone all around its edge. The walls of the gel covering 3 are terminated on the patient interface side with a connecting member 6, which is realized either as a single piece with the gel covering 3 and consists of the same material as the gel covering 3 or as a part that is to be attached by an adhesive or welded joint.

(24) The connecting member 6 is mechanically joined with a base part (not shown) of the mask by means of catching parts, or, alternatively, it can be undetachably joined with the base part of the mask by adhesive bonding or welding. The cavity 9 is bounded by the outer skin 8.

(25) In accordance with the invention, the thickness or depth of the filler 15 can also be essentially constant along the cross section of the gel covering 3.

(26) To fill the cavity 9 with a filler 15, the gel covering 3 has at least one opening, which is not shown in FIG. 1. This opening can be positioned in any desired place in the wall of the gel covering 3 except in the vicinity of the outer surfaces of the contact lips 7 and their surrounding area to prevent it from having a disturbing effect on the facial skin that will be contacted there. The filling hole is preferably sealed by adhesive bonding, welding or plugging with a stopper.

(27) By using a thin filling of the cavity 9, for example, a soft buffer zone is realized. The buffer zone 16 is provided with a supporting function if the cavity 9 is filled with relatively inflexible material, for example, with gel with a hardness above 15 Shore 00. The flexible buffer zone 16 can also be realized in such a way that the filling has two different elastic properties at least in certain areas.

(28) FIG. 2 is a perspective view of a gel covering 3, which has contact lips 7 all around its edge, which are designed to be formed inwardly into the gel covering 3. The wall 6 of the gel covering 3 serves to connect it with the mask body (not shown here) by means of mechanically locking elements, and it contains at least one cavity 9 with a filler 26, which is not shown in the drawing.

(29) FIGS. 3 and 4 show further perspective views of the mask part according to FIG. 2. FIG. 3 reveals openings 10 located in the area of the lower part of the mask. The cavity 9 is filled with the gel through these holes. In one embodiment, the openings 10 are realized as hollows in the outer skin 8, which are sealed with stoppers 11 after the filling operation. In another embodiment, the openings 10 are realized as thickened regions of the outer skin, which are pierced with an injection needle to fill the cavity 9 and which seal themselves due to the elasticity of the material when the needle is pulled out. Ribs 14 are formed in the connecting member 6, which serve a position coding function and determine the orientation. In addition, the ribs allow a pneumatic passage from the interior space of the mask to the pressure gage socket (not shown) of the mask body.

(30) FIG. 4 illustrates especially the use of stoppers 11, which are inserted in the openings 10 of the gel covering 3 after the cavity has been filled with the gel. The fabrication principle will be explained in greater detail later. The openings are preferably formed in the area of the connecting member 6, since the material thickness is greater there. A greater material thickness of the outer skin 8 is to be preferred both for the injection and for the subsequent adhesive bonding of the stopper 11 in the opening 10. The material thickness of the outer skin 8 in the area of the opening 10 is preferably greater than 1 mm in cross section and especially preferably greater than 2 mm in cross section. The opening 10 in the upper right section of the drawing is formed as part of the connecting member 6. Accordingly, the corresponding stopper 11 has the profile of the connecting member 6. The cross section of the stopper 11 reveals a peripheral undercut, which receives a corresponding groove in the mask body. The connecting member 6 has a slightly elevated and beveled insertion aid 17, which helps to achieve simple mounting of the gel rim on the mask body.

(31) FIGS. 5 to 8 show cross sections through cavities filled with filler 15. In FIG. 5, the openings 10 are sealed with stoppers 11, and the cavity 9 is filled with gas. The drawing shows that the material thickness in the area of the connecting member 6 is at least twice as great in some sections as the material thickness in the area of the outer skin 8. In FIGS. 6 and 8, the cavity is homogeneously filled with a filler 15. FIG. 7 shows the openings 10 without stoppers and the cavities 9 without a filling. FIG. 8 additionally shows that the cavity filled with filler 15 can be shaped in various ways. In addition, in cross section, the cavity filled with filler 15 shows its thinnest point 19 in the area of contact with the patient.

(32) The filler 15 in accordance with the invention makes it possible, within a very large range of shaping possibilities, to provide the gel covering 3 with predeterminable increased stability exactly in those areas in which it is needed, while other areas of the gel covering 3 are left with a thin wall thickness and/or a very soft material consistency.

(33) The filling opening repeatedly described above can be designed as an opening in the conventional sense, which is resealed after the filler 15 has been applied. In particular, however, it is also possible to introduce the filler 15 in a flowable consistency by injection into the cavity 9. If this injection of the filler is carried out in a thick-walled region in a covering 8, 11 of the cavity, then, after the injection device has been withdrawn, the injection channel automatically seals itself due to the elastic properties of the material. This greatly facilitates the manufacturing process.

(34) In another embodiment, different material thicknesses of the walls 8, 11 of the gel covering 3 can be chosen, so that, on the one hand, the thickness guarantees the necessary stiffness and, on the other hand, guarantees contact with the skin that is as soft and as tightly sealing as possible.

(35) Especially in the area of the walls of the gel covering 3 that rest against the face, the wall has a smaller material thickness than the areas of the walls of the gel covering 3 that do not rest on any parts of the face 6.

(36) The material thicknesses are preferably low in the area of the walls of the gel covering 3 that rest on the bridge of the nose. It is especially preferred that the material thickness of the wall in the area that rests on the bridge of the nose is less than in those areas of the wall of the gel covering 3 that rest on other parts of the face. This results in an optimal sealing function with minimal application of pressure in the area of the sensitive bridge of the nose.

(37) FIG. 9 illustrates connections between the gel body 26 and a connecting member of the patient interface. The connecting member can consist of polycarbonate. The joint can be realized by a positive-locking connection according to the drawing on the left in FIG. 9, while in the embodiment illustrated on the right, an adhesive bond can also be realized, even with the use of silicone.

(38) FIGS. 10 and 11 show an embodiment of the gel covering 3 of the invention. In this case, the gel covering 3 is joined with the patient interface (mask body) by means of locking mechanical elements in a mask connection area. The mechanical locking element is designed here as part of the outer skin 8 of the gel body, for example, by the double-shot process, and it has a latch that encloses an undercut of the patient interface. In the area of the joint 27 between the gel body 26 and the patient interface, there is a sealing contour (not shown).

(39) FIG. 11 shows that the outer skin 8 is adhesively bonded with the gel body. The outer skin is preferably formed as a thin silicone lip, which overlaps the contact zone of the gel body with the skin. The adhesive joint 20 is located in the area of the connecting member 6. In addition, a locking mechanism that detachably connects the gel body 26 with the body of the patient interface can be realized in the area of the connecting member 6.

(40) FIG. 12 shows a cross section through the joint 27 between the gel body 26 and the connecting member of the patient interface 23. The connecting member of the patient interface 23 can consist of polycarbonate (PC) or PA and is preferably hard. The connection is made here with a snap connection, which can be realized peripherally or only in segments. In the case of nasal masks and full-face masks, a segmented snap connection in the area of the corners of the triangular mask body is preferably contemplated. A recess 29 in the area of the connecting member of the patient interface 23 serves to receive the corresponding snap hook 30. The snap hook frame 31 is injection-molded or adhesively bonded as a hard part peripherally or in segments onto the mask rim 3, 7, 8, 24, 25, 32 (silicone/PU). A sealing element that has at least one sealing contour 33 is located in the joint 27. The sealing element runs peripherally along the joint 27 and preferably provides a sealing effect in the radial direction.

(41) FIG. 13 shows five variants of possible means of connection. The upper three variants in the figure have positive-locking connections between the silicone and the rim of the mask. The fourth embodiment shows adhesive bonding without positive locking. The bonding gap is at least partially filled with adhesive in this case. The fifth embodiment is again a positive-locking connection. Even in the positive-locking connections, additional connection by adhesive bonding is also possible in order to increase the strength of the connection. The strength of the connection can be increased still further if the frame element and the gel rim are also adhesively bonded.

(42) The gel rim and the gel are produced in a mold 34 of an injection molding machine 40, as shown in FIG. 14. To this end, the outer skin 8 (A) (e.g., silicone or TPE) is first injected and becomes deposited on the mold to form the outer skin. The gel (B) is then injected in the same or a second injection unit 41 and fills the entire interior space. It is also conceivable for the gel to first be produced from its two or more components at the time of the injection. For this purpose, at least one component is contained in a reservoir 41. This component is first metered in during or just before the injection of the gel fraction (B). If necessary, the first component is injected again to seal the injection point. This component is injected by the first injection unit or by a third injection unit.

(43) The gel pad according to FIG. 14 is produced with an injection molding unit. To this end, the injection unit is filled in one shot with the first and the second component or the first component again (monosandwich).

(44) It is also possible to inject a harder material as a third or additional component in order, if necessary, to realize a functional element or additional functional elements of the gel rim.

(45) The gel pad according to FIG. 15 is produced with an injection molding unit 41. In this case, the covering blank is transported from a first mold 43 to a second mold 44, where the filling with gel substance is carried out. In this operation, a part of the mold or the whole mold is transferred, together with the article so far produced, from one machine to the other. It is also possible to move only the article between the machines.

(46) However, as shown in FIG. 16, the filling can also be carried out with two, three or more injection units in one machine 40. The units are controlled by the machine and possibly by an additional transfer plate 45. the transfer plate switches from one component (a) to the next (B).

(47) It is also possible, as shown in FIG. 17, to carry out the production process with the use of a machine 40 with an integrated transfer plate 45. In this case, feeding from the various units 41 is controlled in the machine.

(48) The injection operation can be optimized by a pressure buildup with an auxiliary medium between the first and second component. To this end, more material of the first component than is needed is injected into the mold. In an intermediate step, excess material is then forced back out of the mold by the auxiliary medium. Suitable auxiliary media for this purpose are gases as well as liquids.

(49) The gel rim is produced quasi in one operation, in which the so-called monosandwich process is used. In the monosandwich process, two melts are first stratified one after the other in a common worm cylinder, such that the second melt is plasticated by a secondary extruder into the worm cylinder of the main machine. The injection operation is then carried out with only a single stroke, as in conventional injection molding. The sandwich structures result from the flow properties of the axially stratified melts in the worm cylinder.

(50) The material that is injected first is deposited as a skin on the mold wall, and the material which follows forms the core. Thus, with respect to the gel rim, first the silicone skin (outer skin) is formed and then the silicone gel (core layer).

(51) The prefabricated gel rim is manually or mechanically mounted on the frame geometry (double shot frame with a bubble and coupling for the central element), and the joint is adhesively bonded and/or vulcanized.

(52) In this regard, it is contemplated that a projection of silicone 3.0-15.0 mm long is formed beyond the frame (on the patient side), which as a male or female joining unit fits the female or male matching part of the gel mask rim.

(53) Before, during or after the mounting of the gel mask rim, this joint is filled either with a silicone adhesive or with an LSR (liquid silicone rubber). The silicone adhesive is cured under room conditions, while the LSR adhesive joint would be vulcanized under elevated pressure and temperature by means of an additional compression mold.

(54) The nasal pillow mask is a special form of a patient interface and serves to convey gas to the patient's nose. As FIG. 18 shows, the pillows are produced from a soft material, such as silicone, which can be adapted to the shape of the nose, thereby providing a good seal and avoiding leaks. The shape of the pillows is oval or kidney-shaped. The two pillows form a unit. They can provide a seal directly on the edge of the nose or can be slightly inserted into the nose. Gel pads 26 embedded in the nasal pillows 25 can also prevent pressure points that might otherwise develop here. Small accordion folds 36 in the joining area of the nasal pillows allow better positioning of the nasal pillows 25 on the patient's nose.

(55) The nasal pillows 25 are joined to the body 22 of the mask by a holding area made of a harder material. This can be joined with the nasal pillows by the double shot process and is held on the body 22 by a locking mechanism. Another variant provides direct joining of the soft nasal pillows 25 to the body 22. In this connection, the nasal pillow 25 is folded over the body 22 and held in the holding area 24 of the body 22. This holding area 24 can be formed in such a way that it forms the end support of the ball-and-socket joint 10.

(56) In another embodiment, the ball of the ball-and-socket joint 10 can be inserted from the outside into the holding area 23 of the body 22 by the application of a small amount of force. To this end, it is provided that the ball or the socket is made of a stable plastic material, which readily elastically yields and deforms under the pressure of insertion of the ball but then returns to its original shape and holds the ball.

(57) FIG. 19 shows a side view of and a longitudinal section through a nasal pillow. To bound the cavity 9 for receiving the gel filling, the component of the extension 45 of the nasal pillow cushion 38 that extends to the left is produced, and after it has been released from the mold, this extension 45 is folded over towards the inside. This bounds the inside of the cavity, and the gel filling is shielded from the interior space. The extension 45 that has been folded over can be adhesively bonded with the other wall material. A bending point, which in the present case takes the form of a notch, is provided in the area of the extension 45. This makes it easier to fold over the extension and provides the length of the extension 45 to be folded over. In its folded state, the extension reaches as far as the stop 47.

(58) FIG. 20 shows a side view of and a longitudinal section through a nasal pillow with the extension folded over. The cavity 9 for receiving the gel filling is bounded here on the gas-carrying inside by the extension 45 and on the outside by the outer skin 8. To this end, the extension 45 was folded over as far as the stop 47 and adhesively bonded. It is seen that the wall thickness of the outer skin 8 is lesser in the area of the nasal pillow cushion 38 that holds the gel filling than in the area that lies below the stop 47. The lesser wall thickness supports the pressure-relieving and sealing function of the gel filling.

(59) FIG. 21 shows a side view of and a longitudinal section through a nasal pillow that consists of two parts. The body 25 of the nasal pillow and the nasal pillow cushion 38 are produced separately, and the nasal pillow cushion 38 is filled with the gel before it is joined with the body 25 by adhesive bonding.

(60) Naturally, all of the geometries are conceivable/realizable in mirror-image arrangement (as an example, the groove in the silicone shoulder of the frame and the plug in the gel mask rim).

(61) It is also possible for the geometry to be such that, e.g., the female end is preformed in such a way that it does not deform into its final position until it is mounted on the opposing end (male part). This effect would promote secure support and satisfactory adhesive bonding.

(62) The embedding of gel fillings is accomplished by filling sections of the nasal pillow. This makes it possible to realize better wearing comfort and/or better strength. The material of the nasal pillows is usually silicone. The embedded gel is a silicone gel, which is realized with a hardness in the range of less than 20 Shore 00, preferably with a hardness in the range of 10-20 Shore 00, and more preferably with a hardness on the order of 15 Shore 00. Surprisingly, it was found that gel with a Shore hardness on the order of 15 Shore 00 is especially well suited for sealing the patient interface airtight at elevated ventilation pressure in the contact zone with the underside of the nares in a way that provides sufficient support and at the same time is comfortable for the patient.

(63) The filling can be carried out in a variety of ways. In a first variant, the nasal pillows can be realized as a single piece, and the gel filling 26 can be injected through a membrane 39 in the covering that is located on the side of the nasal pillows that faces away from the patient. Each nasal pillow has two membrane openings 39, which serve the purpose of filling and simultaneous venting during filling. This is illustrated in FIG. 22. In another variant (FIG. 23), the body 25 of the nasal pillow and the two nasal pillow cushions 38 are produced separately, and the nasal pillow cushions 38 are filled with the gel 26 before it is joined with the body 25 by adhesive bonding.

(64) The nasal pillow cushions 38 and the body 25 of the nasal pillow are secured against torsion by a tongue-and-groove joint to prevent incorrect assembly of the nasal pillows. The wall shape and thickness of the pockets to be filled with gel can be variable. The gel filling is preferably located in a region of the nasal pillows that rests against the underside of the nares and also extends at least partially into the region of the nasal pillows, which are inserted in the nose. In addition, the silicone covering is 10-50% thinner in the area of the gel fillings than the rest of the wall and preferably 20-40% thinner in order to guarantee better adaptation to the patient.

(65) Other variants of embodiments with support on the bridge of the nose or on the side of the nose allow the patient a free field of vision. For one thing, the nose support can be accomplished by means of small, commercially available spectacle bridges or by a relatively large-area gel pad, which is mounted on the nose support and preferably is suitable for patients who are very sensitive to pressure. The mount of the nose bridge support is connected by a snap-in mechanism with the guide part of the forehead support, so that optimum adjustment is guaranteed. The variants of embodiments shown in FIGS. 22 and 23 can be realized both as a nose support without a forehead support and as a nose support with a forehead support.

(66) By varying the silicone Shore hardness, e.g., the attachment region in the gel variant, more precisely, the double shot bubble and the actual connection shoulder, could be harder than in the standard silicone variant injected in one piece. This would not be noticed or would hardly be noticed (not disturbing) in a comparison of gel with silicone and would be helpful during mounting.

(67) It is also possible to produce the gel forehead pad covering by a type of gas injection technique. In other words, the forehead plate is inserted in a production mold, and silicone is injected through a borehole within the forehead plate (plastic plate that serves as a locking element of the forehead pad) in such a way that the silicone is deposited only on the outer covering of the bell-shaped forehead pad (material is deposited as a skin on the inside of the mold wall) (wall thicknesses of 0.5-1.0 mm). This technique allows fabrication of the covering without a mold core (steel core that forms the inner region of the covering in a conventional mold).