A nasal mask

IS 2 250 263 T3

DESCRIPTION

Nasal mask.

This invention relates to patient interfaces particularly, but not only, to a nasal mask intended to be used to provide CPAP therapy to patients suffering from obstructive sleep apnea (OSA).

Background of the invention

In the art of respiratory devices, there is a well-known variety of respiratory masks that cover a person's nose and / or mouth to provide a continuous seal around the nasal and / or oral areas of the face so that it can be providing a gas with a positive pressure within the mask to be consumed by the wearer. The use of such masks ranges from high altitude breathing (for example, in aeronautical applications) to mining and firefighting applications, to various medical diagnostic applications and therapeutic applications.

A requirement of such respiratory devices has been that they provide an effective seal against the wearer's face to prevent leakage of the gas being delivered. Ordinarily, in prior art mask configurations, a good seal of the mask to the face had in many cases been achieved only with considerable discomfort to the user. This problem is crucial in most applications, especially medical applications, which require the user to wear such a mask continuously for hours or perhaps even days. In such situations, the user will not tolerate the mask for long periods and optimal diagnostic or therapeutic goals will not be achieved, or will be achieved with great difficulty and considerable discomfort to the user.

Where masks such as those previously used in respiratory therapy are used, particularly in the treatment of obstructive sleep apnea (OSA) using Continuous Positive Airway Pressure (CPAP) therapy, a Ventilation for the expulsion of the derived current or the gases expired to the atmosphere. That type of vent can be provided, for example, as part of the mask, or in the case of some respirators where an additional conduit carries the expiratory gases, in the respirator. The expulsion of gas from the mask is essential to ensure that the development of carbon dioxide will not occur during the circulation interval. With typical flow rates in CPAP treatment, usually between 4 cm of H₂O and 20 cm from H₂Or, prior art solutions with such vents have proven excessively noisy causing user irritation and concentrated gas streams irritating any bed partner.

Various solutions have been developed in the prior art to try to reduce noise when providing CPAP therapy. For example, in PCT Patent Application No. WO98 / 34665 it has been proposed that the vent include an elastic plug with rounded edges at the opening to reduce noise. A vent with a semi-annular fin is provided in PCT Patent Application No. WO00178382. However, these prior art methods are not entirely satisfactory in eliminating the extraordinary noise created by a vent in the mask.

In WO98 / 48878 a respirator mask is disclosed which includes a damped air discharge opening which is connected to supply gases piped into a mask. The discharge opening is damped by means of a tubular shaped interchangeable filter seated within a tubular conduit extending from the opening.

Summary of the invention

An object of the present invention is to try to provide a nasal mask that partially overcomes the above-mentioned drawbacks of the prior art or that at least provides a useful option to industry.

Consequently, the invention consists of a device for administering a supply of gases to a user as defined in claim 1.

Preferred embodiments are defined in claims 2 to 8.

Those skilled in the art to which the invention is concerned will suggest many changes in construction and embodiments and applications that differ greatly from the invention without departing from the scope of the invention as defined in the appended claims. The disclosures and descriptions in this specification are purely illustrative and are not intended to be limiting in any way.

The invention is based on the foregoing and also contemplates constructions of which the following examples are given.

Brief description of the drawings

A preferred form of the present invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a block diagram of a humidified, continuous, positive airway pressure system (CPAP system) that can be used in conjunction with the present invention;

Figure 2 is an illustration of a nasal mask that can be used with the present invention;

Figure 3 is a front view of a nasal mask illustrating a headgear attachment to the mask;

Figure 4 is a perspective view of a mask illustrating a plurality of application fasteners connecting with the slip strap;

Figure 5 is a perspective view of a mask showing a slip strip captured in the application fasteners;

Figure 6 is a side view showing the slide strip;

Figure 7 is a perspective view of the mask illustrating outlet vents in accordance with the present invention;

Figure 8 is a perspective view of the mask illustrating the vent cover in place; and Figure 9 is a perspective view of the vent cover.

Detailed description of the preferred embodiments

The present invention provides improvements in the field of CPAP therapy. In particular, an output is described which is less noisy and has a more diffuse output current. It will be appreciated that the nasal mask as described in the preferred embodiment of the present invention can be used in the

EN 2 250 263 T3 respiratory care in general or with a ventilator but will now be described below with reference to use in a humidified CPAP system. It will also be appreciated that the outlet vent described is equally applicable to all forms of interface of the patent, in particular to a buccal placement.

With reference to Figure 1, it shows a humidified Continuous Positive Air Duct Pressure (CPAP) system in which a patient 1 receives pressurized and humidified gases through a nasal mask 2 (or another type of interface). patient number) connected to a type of gas transport line or inspiratory line 3. It is to be understood that delivery systems could also be VPAP (Variable Positive Airway Pressure) and BiPAP (Two Level Positive Airway Pressure) or numerous other forms of respiratory therapy. The inspiratory conduit 3 is connected to the outlet 4 of a humidification chamber 5 containing a volume of water

6. The inspiratory conduit 3 may contain heating means or heating wires (not shown) that heat the walls of the conduit to reduce condensation of humid gases within the conduit. The humidification chamber 5 is preferably formed from a plastic material and may have a highly heat conductive base (for example an aluminum base) which is in direct contact with a heater plate 7 of the humidifier 8. The humidifier 8 is provided with control means, or electronic controller, 9 which may comprise a microprocessor-based controller that executes computer software commands stored in associated memory.

Controller 9 receives inputs from sources such as user input means or indicator 10 through which a user of the device can, for example, set a required value (preset value) of the humidity or temperature of the gases supplied to the patient. 1. The controller may also receive inputs from other sources, for example, temperature and / or flow velocity sensors 11 and 12 through connector 13 and heater plate temperature sensor 14. In response to the degree of humidity set by the user by means of the indicator 10 of the input path of the temperature value and the other inputs, the controller 9 determines when (or at what level) to activate the heater plate 7 to heat the water. 6 inside the humidification chamber 5. As the volume of water 6 is heated within the humidification chamber 5, the water vapor begins to fill the volume of the chamber above the surface of the water and is drawn out of the humidification chamber 5 through the outlet 4 with the gas stream (for example air) provided from the gas supply means or blower 15 entering the chamber through the inlet 16. The gases exhaled from the patient's mouth pass directly to the environment around him in figure 1.

The blower 15 is provided with variable pressure regulating means, or a variable speed fan 21, which draws air or other gases through the blower inlet 17. The speed of the variable speed fan 21 is controlled by the electronic controller 18 (or alternatively the function of the controller 18 could be performed by the controller 9) in response to inputs from the controller 9 and to a user-set predetermined required value (preset value ) of the pressure or fan speed by means of the indicator 19.

Nasal Mask

Referring to Figure 2, a nasal mask that can be used with the present invention is shown in detail. The mask includes a hollow body 102 with an inlet 103 connected to the inspiratory passage 3. The mask 2 is positioned around the nose of the user 1 with the headgear 108 secured around the back of the head of the patient 1. The restricted force of the headgear 108 on the hollow body 102 and forehead rest 108 ensures sufficient compressive force on the mask cushion 104 to provide an effective seal against the patient's face.

The hollow body 102 is constructed of a relatively inflexible material, for example, polycarbonate plastic. That type of material will provide the required stiffness as well as transparency and is a relatively good insulator. The expiratory gases in the preferred embodiment of the present invention are expelled through a valve in the mask 300, or alternatively through a further expiratory conduit (not shown), or by any other method as is known in the art.

Mask head gear

Referring now to Figures 2 and 3 the headgear 108 is shown connected to the hollow body 102. The present invention instead of traditional fixed or adjustable ties utilizes a sliding application between the headgear 108 and the hollow body 102 This is accomplished by a loop 120, which extends through equipment clips 122, 124 on each side of headgear 108 and over the top of hollow body 102. The loop 120 is alternately applied with guides 126, 128 mounted on the upper surface of the hollow body 102. The guides limit the loop 120 but allow it to slide in and out, which means that the headgear 108 can move laterally, independently hollow body 102.

The advantage of this solution is that as the face is contoured during various sleeping positions, the headgear is able to move with changes in position while the mask remains in the correct position on the wearer's nose and a seal is maintained. effective.

The additional guides 129, 130, 131 allow the user to adjust the position of the loop 120, which allows a different pressure to be obtained on the seal that depends on the position of the loop 120.

To better ensure user comfort and effective pressure on mask cushion 104, headgear 108 can be constructed using two straps that extend around the back of the wearer's head as shown in Figure 2 or with a partial head covering or any other configuration, as is known in the art. In this case the straps, or the partial head covering would be made using neoprene but can also be made using any other material, as is known in the art, that is comfortable for the user.

In a further example, shown in Figures 4, 5

ES 2 250 263 T3 and 6, a nasal mask is illustrated using a slide strap to secure the headgear 108 to the hollow body 102. The strap 200, shown in Figure 6 in isolation, is constructed of polyacetal (Delrin 500P NC010 ) using injection molding techniques to obtain a polished finish. This material, similar to other nylon-based derivatives, with its polished finish has a very effective particularly low friction, and glides relative to the hollow body 102 with very little resistance. As shown in Figure 4, the hollow body 102 includes a number of engagement fasteners 202, within which, in use, the slip strip 200 snaps and engages with them, requiring substantial force to withdraw. the strap of fasteners 202. This means that with normal use the slip strap 200 will remain retained within the application fasteners 202. It will also be appreciated from Figure 4 that a number of fasteners are provided, to allow pressure from different angles for different face shapes.

As shown in Figure 6, the slide strip includes a midsection 204 adapted to reciprocate relative to the engaging fasteners 202, terminating at each end with hooks 206, 208 that are attached to the headgear. The first hook 206 is a complete loop through which the head member 108 is permanently attached, for example, with a velcro strap. The loop 208 at the other end is only a partial loop 210 designed so that a strap or loop of the headgear 108 can easily be slipped into or out of the open section 212 allowing easy removal and attachment of the mask.

It should be noted that the appended claims specifically refer to the patient interface and the outlet vent described below. The above description regarding the mask and mask head kit is intended to describe a particular embodiment of a patient interface that may be included in a patient interface with an outlet vent as described below.

Outlet Vent

As shown in Figures 7 to 9, the present invention includes an outlet vent 300 as part of the body portion. The outlet vent 300 includes a number of openings 302, molded into the body portion 102 or then drilled through the mold. The openings 302 are spaced apart and partly surrounded by a number of partitions 304 that provide support for a filter cover that is installed on top of the openings 302. The filter cover is basically designed to avoid noise that would otherwise be generated by the circulation of gases through the openings 302 externally. The filter cover comprises a frame member 306 (shown in Figure 9) that snaps onto the top of partition 304 and holds in place a middle filter piece 308 that sits on top of partitions 304. Frame 306 includes large vents 307 such that expiratory or skew current from the mask exits openings 302 through filter media 308 and out of vent 307. Piece of filter media 308 is preferably medium (PM35) of Ecofit brand filter that has less tendency to block at the humidity levels often found in such applications.

The structure of the outlet vent allows the filter media to be replaced when desired, or needed, in an easy and efficient way. Frame 306 can be easily removed, filter media 308 replaced, and frame 306 snapped back into place. In addition, in the rare case that the filter media becomes blocked, auxiliary vents 310 are provided in the frame 306 that mate with the gaps 312 in the partitions 304. As the auxiliary vents 310 are much smaller than the main vents 307 during normal use, very little circulation passes through them. If the filter media 308 becomes blocked, the flow is then forced through the auxiliary vents 310. This noise will be significantly louder than normal and will indicate the need for maintenance to the user.

It should be noted that by providing such a system, the present invention effectively minimizes the noise generated by the exhaust stream of expiratory gases from the mask. The present invention is of a low maintenance type and when replacement of the filter medium is required it is an easy and simple operation. In addition to reducing the noise level, the circulation through the exhaust vent is more diffuse. This avoids, for example, a circulation of gases directed at a sleeping partner or a similar current directed at the patient, either of which would cause discomfort or wake the partner.

The features described in the preceding description, in the claims and / or the accompanying drawings may, both separately and in any combination thereof, be material for carrying out the invention in various forms thereof.