A nasal mask

IS 2 178 980 T3

DESCRIPTION

Nasal mask.

Field of the invention

This invention relates to nasal masks particularly, but not only, for use in providing CPAP (Continuous Positive Airway Pressure) 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 the nose and / or mouth of a person 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 for consumption 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 masks has been to 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 only been achieved in many cases 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.

In common with prior art designs, there is an inability to seal effectively when the wearer's / wearer's face becomes distorted. For example, as shown in the prior art mask of Figure 1 when user 300 is sleeping on their side, one side 302 of the headgear tends to be tight while the other side tends to be loosened. This causes the axis of the mask 306 to be twisted relative to the axis of the head 308, due to the net torque applied to the headgear, which causes a leak 310 on one side. The user 300 sleeping on their side may also distort the facial contours around the nasal area 312 and may lead to further leakage.

US 5,832,918 describes a respiratory device having a typical hard domed mask and a strap attached to the mask dome.

Summary of the invention

An object of the present invention is to try to provide a nasal mask which partly overcomes the aforementioned drawbacks of the prior art or which at least provides industry with a useful option.

Consequently, the present invention provides a device having the features of claim 1.

The invention is comprised of the foregoing and also contemplates constructions of which the following examples are provided.

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 plan view of a prior art mask illustrating a side leak.

Figure 2 is a plan view of a mask according to the preferred embodiment of the present invention;

Figure 3 is a block diagram of a humidified continuous positive airway pressure (CPAP) system that can be used in conjunction with the present invention;

Figure 4 is an illustration of the nasal mask used in accordance with the preferred embodiment of the present invention; Figure 5 is a front view of a nasal mask illustrating attachment of the headgear to the mask; Figure 6 is a perspective view of the mask showing multiple applicator clips;

Figure 7 is a perspective view of a mask that does not incorporate the present invention showing the slip strip captured in place; and Figure 8 is a side view of the slide strip.

Detailed description of the preferred embodiments

The present invention provides improvements in the field of nasal masks for use in CPAP therapy. In particular, a nasal mask is disclosed that is more comfortable to be worn by the user and reduces lateral leakage compared to prior art masks. It will be appreciated that the nasal mask as described in the preferred embodiment of the present invention can be used in respiratory care in general or with a ventilator but will now be described later with reference to use in a humidified CPAP system.

With reference to figure 3, 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 connected to a transport route. humidified gas or inspiratory duct 3. It is to be understood that the 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 3.

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 4, the nasal mask is shown in detail, according to the preferred embodiment of the present invention. The nasal mask includes a hollow body 102 and an inlet 103 connected to the respiratory 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. Expiratory gases can be expelled through a valve (not shown) in the mask, an additional expiratory passage (not shown), or by any other method as is known in the art.

Mask Head Kit

Referring now to Figures 4 and 5, these show the headgear 108 connected to the hollow body 102. The present invention instead of the traditional fixed or adjustable tethers 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 body

ES 2 178 980 T3 hollow 102. The guides limit loop 120 but allow it to slide in and out, which means that headgear 108 can move laterally, independent of 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 further 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 4 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 embodiment, shown in Figures 6 and 8 of the present invention, there is illustrated using a slide strap to secure the headgear 108 to the hollow body 102. The strap 200, shown in Figure 8 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 therefore slides relative to the hollow body 102 with very little resistance.

As shown in Figure 6, the hollow body 102 includes a number of engagement fasteners 202, within which the slip strip 200, in use, is elastically applied and can only be removed therefrom using force. substantial. This means that with normal use the slip strip 200 will remain retained within the application clips 202. It will also be appreciated from Figure 6 that a number of fasteners are provided, to allow pressure from different angles for different face shapes.

As shown in Figure 8, the slide strip includes a midsection 204 adapted to reciprocate relative to 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 be easily slid into or out of the open section 212 allowing easy removal and attachment of the mask.

It should be noted that in all embodiments of the present invention, the attachment of the headgear to the mask is designed to slide with as little friction as possible while ensuring adequate direct force on the cushion of the headgear. mask on the wearer's face. As shown in Figure 2 the slide connection 320 allows the headgear 322, 324 to provide a uniform force on both sides of the mask 326. This avoids applying torque to the mask and twisting the chamber while minimizing leakage of the mask from the face 326 seal.