Forehead pad and forehead support using same

A forehead pad that includes a base member having a first side adapted to be coupled to a forehead support member. The pad also includes a patient contacting member having a first side adapted to contact a surface of a patient. A neck portion couples a second side of the base member and a second side of the first patient contacting member. The neck portion includes at least one cutout to allow at least a portion of the first patient contacting member to move relative to the base member so that the patient contacting portion of the pad is self-aligning with the surface of the patient even if the base member is not parallel with the surface of the patient.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a forehead pad and forehead support pad for use in a forehead support portion of a patient interface device, such as a nasal or full face mask.

2. Description of the Related Art

There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle or with the condition of the patient (auto-titration pressure support systems), to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA) or congestive heart failure.

Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device, which is typically a nasal or nasal/oral mask, on the face of a patient to interface the ventilator or pressure support device with the airway of the patient so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. Because such masks are typically worn for an extended period of time, it is important the mask fit properly and comfortably on the patient. This is made difficult in that in order for the mask to maintain a seal without any undue gas leaks around the periphery of the mask, the mask may be compressed against the patient's face.

It is known to provide forehead supports associated with gas delivery masks to provide a support mechanism between the mask and the patient's forehead. Gas delivery masks having forehead cushions, spacers or supports are described in U.S. Pat. Nos. 4,907,584; 5,243,971; 5,570,689; 6,119,693; 6,357,441; 6,463,931; 6,467,483; 6,520,182; 6,532,961; 6,557,556. The forehead supports prevent the mask from exerting too much force on a patient's face and provides stability to the mask.

The forehead support devices in the above-identified patents typically have at least one forehead pad attached to the forehead support. The forehead pad contacts the surface of the patient. In U.S. Pat. Nos. 4,907,584; 5,243,971; 5,517,986, 5,570,689, and 6,357,441 the forehead support pads typically made of foam and have a generally rectangular or trapezoidal in shape with relatively sharp edges. The conventional forehead pads taught in U.S. Pat. Nos. 6,119,693; 6,463,931; 6,467,483; 6,520,182; 6,532,961; and 6,557,556 have a semi-circular profile to compensate for any angular variation between the forehead support structure and the surface of the patient. The disadvantage of that is the pad rests on the forehead on a curved surface which translates into pressure point. These semi-circular designs allow the curved contact to compress and deform to secure a flatter contact. Again, that creates pressure points and it is not the most comfortable option.

The product literature for the MAP Papillon mask shows a forehead pad that attaches to the forehead support via a stem. The stem and/or the attachment of the stem to the forehead support frame allows for some articulation of the main portion of the forehead pad. However, the relatively small size of the stem provides a relatively unstable platform for mounting the forehead pad on the support frame.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a forehead pad that overcomes the shortcomings of conventional forehead pads. This object is achieved according to one embodiment of the present invention by providing a forehead pad that includes a base member having a first side adapted to be coupled to a forehead support member and a second side. The forehead pad also includes a patient contacting member having a first side adapted to contact a surface of a patient and a second side. A neck portion is coupled to the second side of the base member and the second side of the patient contacting member to join these to portions of the forehead pad. The neck portion includes at least one cutout to allow at least a portion of the patient contacting member to move relative to the base member. This configuration allows the patient contacting member to automatically adjust relative to the base member so as to allow the first side of the patient contacting member to lie flat on the surface of the patient even if the base member is not parallel to the surface of the patient.

It is yet another object of the present invention to provide a forehead support assembly including the forehead support pad of the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1-3Cillustrates a first exemplary embodiment of a forehead pad30according to the principles of the present invention. Forehead pad30includes a base member32having a first side34adapted to be coupled to a forehead support member and a second side36. Forehead pad30also includes a patient contacting member38having a first side40adapted to contact a surface of a patient and a second side42. A neck portion44couples second side36of base member32and second side42patient-contacting member38. In a preferred embodiment of the present invention, the base member, patient contacting member and neck portion are integrally formed from a common material, such as a low-durometer silicone or soft elastomer.

Neck portion44, base member32, and patient contacting member38are configured such that a cutout, generally indicated at46aand46b, is provided on each side of the forehead pad. Cutouts46aand46ballow at least a portion of patient contacting member38to move relative to base member32, as indicated by arrow A. In other words, a cantilever member48aand48bis formed on each side of patient contacting member38. Cantilever members48aand48bare deflectable toward base member32as a compression force is applied to first side40of patient contacting member38.

The flexibility of the material defining the patient contacting member and the neck portion as well as the cutout portions at the neck region allows patient contacting surface40to rock up-and-down, as indicated by arrow A, when the forehead pad is compressed. Cutouts46aand46balso absorb the force acting on the forehead. Thus, the forehead pad of the present invention ensures a flat contact that provides optimal comfort to the patent regardless of the angle at which the overall forehead pad contacts the patient. In other words, any angle between the base member and the surface of the patient is adjusted for by allowing the patient contacting member to change position relative to the base member. As a result, the surface of the forehead pad contacting the patient evenly distributes the loading to eliminate pressure points. In addition, this configuration of the forehead pad allows the pad to self align with the forehead so it will always maintain a flat surface contact.

In the illustrated embodiment cutouts46aand46bare sized and configured such that an angle α of approximately 30 degrees is defined between second36side of base member32and second side42of the patient contacting member38. It is to be understood that other angles are possible depending on the freedom of movement desired for the patient contacting member. In addition, cutouts46aand46bare shown as being symmetrically disposed on each side of the forehead pad. It is to be understood that either of these cutouts can be eliminated so that only one cutout is provided. Of course, this configuration will limit the degree of movement for the patient contacting member.

It is to be further understood that other cutout arrangements can be provided to allow movement of patient contacting member38relative to base member32in other dimensions. For example, the present invention contemplates providing cutouts47aand47bon the sides of the pad, and not just on the front and back portions. Thus, additional cantilevered members49aand49bare formed from patient contacting portion due to side cutouts47aand47b.

In the illustrated exemplary embodiment, first side40of patient contacting member38is relatively planar, i.e., relatively flat. It is to be understood, however, that other configurations for the patient contacting member and patient contacting surface40of the present invention are contemplated by this invention. For example, first side40can be provided with a slight concavity to account for the slight rounding present in the forehead of many humans.

Forehead pad30attaches to a forehead support member50in a forehead support structure, generally indicated at51in a patient interface device.FIGS. 4-5Cillustrate forehead support30attached to a forehead support member50. More specifically, these figures show two separate forehead pads attached to two ends of forehead support member50. It should be understood that the forehead support member shown inFIGS. 4-5Crepresents only one potential configuration for the forehead support member. In the embodiment, forehead support member50includes a first coupling portion52that slideably engages a second coupling member (not shown) that extends from the mask shell (also not shown). Of course, forehead pad30is also suitable for forehead support systems in which the forehead support member is not moveable relative to the remainder of the mask.

To allow the forehead pad to attach to forehead support member50, forehead pad30includes an attachment member54coupled to first side34of base member32. In the illustrated exemplary embodiment, attachment member54protrudes from first side34so that it can engage a cooperating element in the forehead support member. For example, the present invention contemplates providing a slot in the forehead support member serving as the receiving element for the attachment member. A stem portion56of attachment member inserts into the slot (not shown), and protrusions58aand58bextending from the stem cooperate with the inside surface of the slot to maintain the forehead pad in an engaged relation with the slot. This is perhaps best shown inFIG. 4. Furthermore, this slot and protrusion configuration allows the forehead pad to be removeably attached to the forehead support member simply by providing an open end to the slot or by deforming protrusions58aand58bduring insertion of attachment member54into the slot and allowing them to return to their original shape following insertion.

It is to be understood that the attachment structure shown inFIGS. 1-5represents only one possible configuration for attaching the forehead pad to the forehead support. Other configuration are contemplated by the present invention. For example, a slot can be provided in first side34of base member32and a protrusion provided in the forehead support member. In addition, or in the alternative, the ends of the base member can provide a surface or other attaching point.

The present invention also contemplates that the attachment member can be eliminated. In which case, the base member can be affixed to the base member using other techniques, such as by directly bonding the base member to the forehead support member via any conventional chemical process. The present invention also contemptates bonding the base member to a separate attachment structure to provide a more rigid attachment for the forehead support. The separate attachment structure can be formed form, a polycarbonate or other thermoplastic.

FIGS. 6-10Cillustrates a second exemplary embodiment of a forehead pad60according to the principles of the present invention. Forehead pad60has a patient contacting member62and a neck portion64that are similar to the patient contacting member and neck portion ofFIGS. 1-5C, including cutouts66aand66b. The primary difference between the second forehead pad embodiment ofFIGS. 6-10Cand the first embodiment ofFIGS. 1-5Cresides in the configuration of base member70and the use of two patient contacting members62with a common base member70. As in the previous embodiment, the base member, patient contacting member, and neck portion are integrally formed from a common material, such as a low-durometer silicone or soft elastomer. This configuration allows a single part, i.e., forehead pad60, to be attached to a forehead support member and provide two points of contact with the surface of the patient, i.e., at patient contacting members62, rather than using two separate forehead pads, as shown, for example, inFIGS. 4-5C.

As in the previous embodiment, the patient contacting members are moveable relative to the base member70due to the cutouts66aand66b. In addition, cutouts68aand68bare provided on the sides of the neck portions to provide further degree of movement for the patient contacting members.

In the illustrated exemplary embodiment, a pair of attachment members72are provided for attaching forehead pad60to a forehead support member74.FIGS. 9-10Cshow the attachment of forehead pad60to forehead support member74. It should be noted that the forehead support member shown inFIGS. 9-10Cis only a portion of the entire forehead support structure. For example, a support art (not shown) attaches to forehead support member at location76(seeFIG. 10A). Attachment members72, like those in the first embodiment, include a stem78and protrusions80aand80bextending from the stem to maintain the stem in engagement with a channel or slot in the forehead support member.

The present invention also contemplates providing further structures on the patient contacting portion of patient contacting member38and62. For example, a fabric or other woven material can be disposed on surface40to enhance patient comfort and to allow any moisture that would otherwise be trapped between the surface of the patient and the surface of the patient contacting member to evaporate.

FIGS. 11-13illustrate a third exemplary embodiment of a forehead pad90and a forehead support member92according to the principles of the present invention. Forehead pad90includes a patient contacting member94, a neck portion96, a base member98, and cutouts on each side of the forehead pad, all of which are generally similar to those features shown in the forehead pad ofFIGS. 1-5C. One difference between the third forehead pad embodiment ofFIGS. 11-13and the first embodiment ofFIGS. 1-5Cis that forehead pad90is more square-shaped than the first embodiment. Also, base member98does not include a protruding attachment member. Instead, the base member includes a slot100that receives a protruding member102provided on forehead support member92so that the forehead pad can be selectively attached to the forehead support. As in the previous embodiments, the base member, patient contacting member, and neck portion are preferably integrally formed from a common material, such as a low-durometer silicone or soft elastomer. Of course, the present invention also contemplates that these portions of the forehead pad, or combinations of these portions, can be formed separately from separate materials and joined using any conventional technique to form the overall forehead pad.

Another feature of forehead pad90not found in the previous embodiments is a groove104defined in a patient contacting surface106of patient contacting member94. Groove104is provided to minimize or prevent the patient contacting surface from form a suction on the surface of the patient when the forehead pad contacts the user. Groove104also helps to vent air between patient contacting surface106and the user's skin. It is to be understood that the present invention contemplates that groove106can have other configurations, sizes (length/width/depth), and that more than one groove can be provided in the patient contacting member. These multiple groove can be intersecting or independent of one another on patient contacting surface106.

Forehead support member92is configured to selectively lock onto a portion of a mask. To this end, the forehead support includes locking members108that fit into slots defined in the portion of the mask to which the forehead support attaches. An example, of a mask that includes a protrusion or tab extending from the mask shell over the patient's forehead to which a forehead support selectively attaches is described in U.S. Pat. No. 6,467,483 to Kopacko et al., the contents of which are incorporated herein by reference. Locking member108includes protrusions110aand110bthat engage the sides of the slots to maintain the forehead support in contact with the mask.

In the illustrated embodiment, a plurality of alignment tabs112are also provide on forehead support. These tabs allow the distance between the forehead pad and the forehead attachment portion of the mask to which the forehead pad attach, to be controlled. When the forehead support is disposed in a first orientation relative to the forehead attachment portion of the mask, alignment tabs112fit into slots defined in the forehead attachment portion of the mask so that a surface114of a base portion116is generally adjacent a surface of the forehead attachment portion of the mask. In this orientation, locking tab110afix the locking member to the forehead attachment portion of the mask. When the forehead support is disposed in a second orientation relative to the forehead attachment portion of the mask, for example by being rotated 180°, alignment tabs112do not fit into the slots defined in the forehead attachment portion of the mask, but instead butt against the surface of the forehead attachment portion of the mask. In this orientation, locking tabs110bfix the locking member to the forehead attachment portion of the mask. The Comfort Classic mask manufactured by Respironics, Inc. of Murrysville, Pa., is an example of a mask having a forehead spacer in the distance between the pad and the mask can be controlled in the manner described above.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims.