This is an original U.S. patent application.
The present invention relates generally to medical devices, and more particularly to apparatus for and methods of supporting or dilating external tissue in humans. As disclosed and taught in the preferred embodiments, the tissue dilator devices are particularly suitable for, and are directed primarily to, external nasal dilators for supporting, stabilizing, and dilating nasal outer wall tissues adjacent and overlying nasal airway passages of the human nose. The United States Food and Drug Administration classifies the nasal dilator as a 510(K) Exempt [Medical] Device Class 1, product code LWF, regulation no. 874.3900.
External nasal dilators (END) are well disclosed in the art and are widely available in retail consumer markets where they are generally referred to as nasal strips or nasal dilator strips. In use the END extends over the nose, flexed across the bridge and adhered to the skin surfaces on either side thereof.
The functional part of the END is at least one resilient member (synonymously referred to in the art as a spring, spring member, resilient band, resilient member band, spring band, or bridge) that extends along the length of the nasal dilator. When flexed, the resilient member exerts spring biasing forces that urge nasal passage outer wall tissues outward, stabilizing the outer walls and expanding, or dilating, the nasal passages underneath.
Stabilized nasal outer walls and/or dilated nasal passages increase nasal patency and reduce nasal airflow resistance, beneficially affecting nasal obstruction and nasal congestion primarily about the nasal valve and extending to the nostril opening. Stabilized nasal outer walls are less likely to collapse during inhalation. Dilated nasal passages have increased cross sectional area and greater nasal cavity volume. Stabilization and/or dilation, particularly at the nasal valve, results in a corresponding improvement in nasal airflow, which may have beneficial effects generally, may increase oxygen uptake, may improve sleep, may reduce sleep disturbances, or may improve nasal snoring or obstructive sleep apnea (OSA). External nasal dilators have been shown to have beneficial effects for athletes, particularly in sports where a mouth-guard is worn. For aerobic sports, nasal strips may delay onset of intra-oral breathing, and may create a subjective feeling of increased respiration, which may provide a psychological benefit in competition.
The most prevalent, common and widely available nasal dilators have two or three closely parallel resilient bands extending from end to end of the nasal dilator, and four corner tabs, x, as illustrated in
Roughly half of all nasal strips currently sold consumers in the U.S. retail market are constructed using clear polyethylene (PE) film (also according to Nielsen data) to engage the nasal dilator to the nose; the other half use a nonwoven fabric. PE film is a moisture vapor barrier. That is, the film does not ‘breathe’, or allow moisture vapor—as from the skin of the nose of a user—to pass through its thickness. Additionally, the nasal dilator's plastic resilient member is also impermeable to moisture and air, so 100% of the PE nasal dilator surface area is non-breathable. Where nonwoven fabrics are used instead of PE, only about half of the surface area is breathable, primarily at corner tabs x, as seen in
Buildup of moisture vapor between the nasal dilator and the skin surface of the nose can cause itching and discomfort. Moisture vapor buildup may also cause adhesive failure and thus premature disengagement of the dilator from the skin surface of the nose. Premature disengagement is believed to be the most common complaint from nasal dilator users. However, for users with sensitive skin it is believed that this same buildup of moisture makes a PE film dilator easier to remove and less likely to irritate the skin upon removal. Irritation upon removal is believed to be the second most common user complaint.
Accordingly, there is an unmet need in the nasal strip market, particularly in view of the popularity of PE film nasal dilators, to provide breathable film-based nasal dilators, and to provide nasal dilators with greater breathable surface area while retaining the efficiency of current widely available nasal dilators.
Human skin surfaces have maximum breathability when not covered by an article, such as clothing or a medical device, or by a substance such as lotion or sunscreen. Adhesive articles made of breathable thermoplastic film are generally regarded as being more effective and comfortable on the skin than non-breathable film articles. Breathable films may include those that have an inherent Moisture Vapor Transmission Rate (MVTR), such as polyurethane (PU) film, or may include those that have an engineered MVTR, such as micro-porosity, made by perforating a film's thickness.
Several external nasal dilator prior art references teach that PU films are suitable nasal dilator material choices. However, nasal dilators constructed using PU film have not been heretofore available to consumers. Nasal dilators having a microporous PE film were briefly, but widely, available to U.S. consumers from about 1995 to about 1998.
The present invention provides new and nonobvious external nasal dilators that address unmet needs, that are commercially viable, and which may be mass produced on an economic scale.
Nasal dilators of the present invention have a significantly greater engagement element surface area relative to the resilient element surface area compared to prior art nasal dilators. That greater surface area may be made breathable so as to increase the nasal dilator's moisture vapor transmission rate (MVTR). Greater MVTR generally makes an article worn on the skin for any length of time more comfortable.
Nasal dilators of the present invention comprise an engagement element for securing the nasal dilator to the skin surfaces of a nose of a user, and a resilient element that provides resiliency, or spring biasing forces, for stabilizing or dilating the nasal passages. The engagement element defines a plan view surface area of the nasal dilator that is substantially the same as the most widely available prior art nasal dilators. The resilient element provides the same resiliency or spring biasing force as the prior art nasal dilators, but within a substantially lesser surface area.
Some embodiments include at least one of an opening formed in the engagement element whereby MVTR may be further improved.
The terms spring biasing, spring biasing force, spring force, resiliency, spring constant, etc. as used herein are generally synonymous. Nasal dilators of the present invention may generate spring biasing force in a range of from about 5 grams to about 60 grams. A preferred range is from about 15 grams to about 35 grams for non-athletes, and from about 25 grams to about 45 grams for use in training, conditioning and competition by athletes. Less than 15 grams of spring biasing may not provide enough stabilization or dilation for some users, while greater than 35 grams may be uncomfortable for non-athletic use, such as during sleep, work or study.
The nasal dilator resilient member is semi-rigid; it is flexible out-of-plane with very little or no in-plane elongation. Strictly speaking, the term resilient may be used to describe objects that exhibit either ‘flexure’ or ‘elasticity’. For purposes of the present invention, however, the terms resilient, resiliency, spring biasing, etc., mean flexure out-of-plane, in a direction perpendicular or oblique to the surface plane, while being substantially rigid in-plane. This is different from, for example, an elastic web that stretches in a direction parallel to its surface plane, even though both the elastic web and the nasal dilator resilient member may return at least substantially to their initial positions after stretch or flexure, respectively. Nasal dilators herein may be described as “capable of flexing” (when the dilator is in an initial or un-flexed position), or “flexed” (when the dilator is engaged to the nose of a user).
The present invention is not limited to the illustrated or described embodiments, which are examples of forms of the present invention. All structures and methods that embody similar functionality are intended to be covered hereby. The nasal dilators depicted, taught, enabled and disclosed herein represent new, useful and non-obvious nasal dilator devices having a variety of alternative embodiments. Some embodiments of the present invention may refer to, or cross reference, other embodiments. It may be apparent to one of ordinary skill in the art that nasal dilator features, construction or configuration may be applied, interchanged or combined between and among the preferred embodiments.
For descriptive clarity, certain terms may be used in the specification and claims: Vertical refers to a direction parallel to thickness, such as the thickness of a finished article, a member or component, or a laminate. Horizontal refers to length or longitudinal extent, such as that of a finished article or element thereof, or a direction parallel thereto. Lateral refers to width or lateral extent. Longitudinal also refers to length, perpendicular to width or lateral extent. A longitudinal centerline is consistent with the long axis of a finished device, element, member or layer, bisecting its width midway between the long edges. A lateral centerline bisects the long axis midway along its length, perpendicular to the longitudinal centerline. The terms upper and lower refer to object orientation, particularly in plan views, relative to the top and bottom of the drawing sheet.
Broken lines and dashed lines may be used in the drawings to aid in describing relationships or circumstances with regard to objects:
In the drawings accompanying this disclosure like objects are generally referred to with common reference numerals or characters, except where variations of otherwise like objects must be distinguished from one another. Where there is a plurality of like objects in a single drawing figure corresponding to the same reference numeral or character, only a portion of said like objects may be identified. After initial description in the text, some reference characters may be placed in a subsequent drawing(s) in anticipation of a need to call repeated attention to the referenced object. Where a feature or element has been previously described, shadow lines (dashed lines) may be used to generically illustrate the feature or element. Drawings are rendered to scale, but may be enlarged from actual size for illustrative clarity. Thickness may be slightly exaggerated in perspective views for illustrative clarity.
As particularly seen in
Dilator layers may be secured to each other by any suitable means such as stitching or fastening, heat or pressure bonding, ultrasonic welding, or the like, but are preferably laminated by an adhesive substance disposed on at least one flat surface side of at least one layer.
The plan view periphery and total surface area of dilator 10 may be defined by either the base layer or cover layer. The base and cover layers, either individually or combined, together with a biocompatible adhesive disposed thereon for engaging the skin, provide the engagement element of dilator 10.
As seen in
In
The preferred materials for the base and cover members may be selected from a range of widely available, preferably medical grade, flexible fabrics or thermoplastic films that are breathable or permeable. The most preferable fabric is a synthetic nonwoven, and the most preferred thermoplastic film is from the class of polyurethane (PU) films from about 20 microns to about 60 microns thick. However, a PE film treated with a plurality of microporous openings may also be used.
An MVTR of at least 200 grams per square meter per 24 hours (GSM/24 hr.), is a most preferred minimum for the base and cover member materials. MVTR may be determined by a standard test such as, for example, ASTM F1249, ASTM E96, or ASTM2622. A layer of pressure sensitive adhesive, preferably biocompatible with external human tissue, may be disposed on a flat surface side of the preferred material and covered by a protective, removable, release liner. The disposition of adhesive may be fully coextensive with the preferred material surface area. To increase MVTR, the disposition may be pattern-coated such that a lesser amount of adhesive covers the entire surface area.
The preferred material for resilient members 22 is a thermoplastic resin that may be selected from a range having flexural, tensile and elastic moduli so as to have substantial in-plane rigidity and out-of-plane flexibility at a thickness preferably greater than 0.010″. A most preferred thermoplastic material is a biaxially oriented polyester resin, Poly(ethylene terephthalate) or PET (or boPET). PET is used in a number of medical device applications, is particularly suitable because of its resiliency or spring biasing properties, and is widely available as a medical/industrial commodity.
It should be briefly noted that it may be possible to utilize laser technology to perforate otherwise impermeable thermoplastic resin materials. However, the process may be unsuitable for nasal dilator manufacture on the economic scale required for wide commercial distribution. Furthermore, the perforations could reduce resiliency, requiring that the resilient member have a greater surface area to make up for the deficit.
The vertically stacked layers of dilator 10 may be arranged in several ways. The stacking order of dilator layers, including a peripheral defining layer, may be determined by the preferred material used.
For example, in
As seen in
Where the base layer is made of a flexible fabric and has significantly less surface area than the cover layer, adhesive on the skin-engaging side of the base layer may be optionally eliminated. With or without adhesive, the base layer may also serve as a compressible buffer between the nasal dilator and the skin engaged thereby.
Yet another stacking order is illustrated in
Alternatively, base member 14 and cover member 18 may have substantially similar or identical peripheries, as seen, for example, in
Where it is formed from a PU film, the layer so formed most preferably has a sufficient thickness so as to be dimensionally stable without use of a supplemental carrier liner or stabilizing material layer. It may be apparent to one of ordinary skill in the art that unsupported ultra-thin PU film, for example, typically having a thickness of about 15 microns, is generally difficult to handle, prone to curling in on itself, and thus must be supported by a supplemental carrier liner until the article in question is secured to the skin. Accordingly, a single peripheral defining layer formed from ultra-thin PU film may be less preferable.
Nonetheless,
The range of spring biasing force provided by resilient members 22a and 22b combined is most preferably consistent with that of the prior art nasal dilators shown in
Accordingly, dilator 10 depicted in
Spring biasing force is determined by resilient member dimensions. For example, one to three resilient members formed from PET, each measuring about 2.0″ in length, having a width/combined width of about 0.25″, and a thickness of 0.010″, generate roughly 25 grams of spring biasing force. Resilient members 22a and 22b each preferably have a width less than about 0.12″, and may have a thickness greater than 0.010″ so as to arrive at the preferred range of spring biasing force. If necessary, two or more resilient members may be overlaid or stacked one atop another so as to arrive at a combined thickness greater than 0.010″. Where resilient members 22 are stacked or overlaid, their length and width are preferably substantially the same.
As noted hereinbefore, nasal dilators of the present invention are drawn to scale. The prior art nasal dilators shown in
In that regard,
It may also be visually apparent that the width of body region 37 and corner tab regions 33 and 35 of dilator 10 are substantially the same as corresponding regions of the prior art nasal dilators. In this regard
Thus far it has been demonstrated that resiliency (spring biasing force), periphery, overall surface area, body region width and corner tab region width are substantially the same, if not nearly identical, between nasal dilators of the present invention and the prior art nasal dilators.
Since resilient members of both the prior art nasal dilators and dilator 10 extend fully from end to end, width comparisons may be viewed as one measure of the difference between impermeable (resilient member) surface area and permeable (engagement element) surface area, the latter being greater in dilators of the present invention compared to the prior art nasal dilators. To further compare widths,
Similarly, in
Comparing body region width to combined resilient member width,
Similarly,
Table 1.0 summarizes the aforementioned width comparisons:
Further comparison of differences in impermeable resilient member surface area and permeable engagement element surface area is shown in
Surface areas a, c and d are part of the engagement element extending in between and outward from resilient member surface areas b. As discussed hereinbefore, surface areas a, c and d are permeable, allowing moisture vapor to pass from the skin therethrough (i.e., MVTR); surface areas b do not allow moisture vapor transmission, regardless of the permeability of the engagement material to which the resilient member is secured. Note that surface areas a and d correspond to corner tab regions, which, combined, average about 40.1% of the total plan view surface area for both the prior art nasal dilators and dilator 10. Surface area c corresponds to the body region, which averages 59.1% thereof.
Overall, dilator 10 has roughly 1.4 times more permeable engagement element surface area, and from about 1.6 to 1.7 times less impermeable surface area, compared to the prior art nasal dilators. However, nearly all of the greater permeable surface area is within body region 37. There dilator 10 has from about 2.8 to about 3.6 times more permeable surface area. The ratio of permeable to impermeable surface area for the prior art nasal dilators is roughly 1:1, while for dilator 10 it's from about 2.1:1 to about 2.5:1, which is about 2.3 to 2.4 times greater. Specific detail follows, summarized in Tables 2.0-2.3.
Beginning with the prior art 3-band nasal dilator,
Turning now to the prior art 2-band nasal dilator,
Table 2.0 summarizes the aforementioned a-d surface areas. Additionally, resilient member surface area b and engagement element surface area c combined reflect the total surface area for body region 37 (shown in the last column). Engagement element surface areas a and d combined reflect the surface area for corner tab region 33 or 35 (shown in the first column). Adding the first and last columns together equals 100% of the total nasal dilator plan view surface area. Extrapolating from Table 2.0 shows that permeable surface area makes up from about 43% to 54% of body region 37 (25.0/57.6=43.4 and 33.1/61.5=53.8). Further extrapolating from Table 2.0 shows that resilient member surface area b occupies from about 46.2% to about 56.6% of the body region surface area (28.4/61.5=46.2 and 32.6/57.6=56.6).
Table 2.1 summarizes the ratios between combined engagement element surface areas a, c and d and resilient member surface areas b.
Table 2.2 summarizes the above-described greater permeable engagement element surface area of dilator compared to the prior art nasal dilators:
To further increase breathability,
As a result of opening 40, impermeable resilient member surface areas b remain the same as before for both dilator 10 and the prior art nasal dilators. The combined engagement element surface areas a, c and d remain the same as before for the prior art nasal dilators (because they do not have an opening). However, where surface area c was previously 25.0% of the plan view surface area of dilator 10,
In view of the increased breathable surface area of dilator 10, a hypothetical MVTR, both with and without opening 40, may be estimated and compared between the prior art nasal dilators and dilator 10 by assigning MVTR values to the previously discussed nasal dilator surface areas.
An MVTR value for the impermeable resilient member surface areas b is obviously zero. MVTR for engagement element surface areas a, c and d is based on a rate of 200 grams per square meter over 24 hours (GSM/24 hr.). The MVTR of human skin is believed to be ˜200-400 GSM/24 hr. (“What is MVTR and how is it measured?”, Avery Dennison Specialty Tape Division, U.S. Avery Dennison Corporation, 2018, stus.averydennison.com/std/stus.nsf/ed/). For purposes herein, MVTR for opening 40 is based on a rate of 400 GSM/24 hr.
A total plan view surface area of 11.5 square centimeters is used for the prior art 3-band nasal dilator, and 9.9 square centimeters for dilator 10 that corresponds to the prior art 2-band nasal dilator. These surface areas approximate nasal dilator actual size. As discussed hereinbefore, the prior art 2-band nasal dilator surface area was calculated to be about 0.5% less than corresponding dilator 10, and the surface area of dilator 10 corresponding to the prior art 3-band nasal dilator was calculated to be about 2.7% lesser.
Accordingly, surface area differences are reflected in the Total Surface Area column of Table 3.0. MVTR rates are represented as grams per square centimeter (Gcm{circumflex over ( )}2/24 hr.), which translates to 0.02 for engagement surface areas and 0.04 for opening 40. At 0.15 Gcm{circumflex over ( )}2/24 hr. dilator 10 has more than one-third greater MVTR (36.4%) than the prior art 3-band nasal dilator. At 0.14 Gcm{circumflex over ( )}2/24 hr. dilator 10 has about 40% greater MVTR than the prior art 2-band nasal dilator. Where dilator 10 includes opening 40, MVTR is roughly two-thirds greater; at 0.18 and 0.17 Gcm{circumflex over ( )}2/24 hr., MVTR is 63.6% and 70% greater, respectively.
Total surface areas, engagement surface area and MVTR values are summarized here:
It may be apparent to those of ordinary skill in the art that breathable materials used in medical devices may have an MVTR that is greater than 200 GSM/24 hr. However, the preferred PU film material for nasal dilators of the present invention has a thickness so as to be dimensionally stable, as described hereinbefore. In view of that preferred thickness it is believed that 200 GSM/24 hr. is a more realistic value. Similarly, fabric-based dilators typically utilize two nonwoven layers, each with an adhesive coating on one side. It is thus believed that 200 GSM/24 hr. is a reasonable estimated value for nonwoven dilator construction.