BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a conventional contraceptive diaphragm.
FIG. 2 is a schematic perspective view of a contoured contraceptive diaphragm disclosed in U.S. Pat. No. 5,771,900 to Austin et al.
FIG. 3 is a schematic top view of the contraceptive diaphragm of FIG. 2.
FIG. 4 is a schematic side view of the contraceptive diaphragm of FIG. 2.
FIG. 5 a schematic plan view of a pair of bands wrapped in a coil spring of the diaphragm of FIG. 2.
FIG. 5A is an enlarged portion of the bands illustrated in FIG. 5.
FIG. 6 is a schematic side view of a user grasping the contraceptive diaphragm of FIG. 2.
FIG. 7 is a schematic partial section view showing the contraceptive diaphragm of FIG. 2 during use.
FIG. 8 is a schematic perspective view of a contoured contraceptive or non-contraceptive diaphragm according to aspects of the present invention.
FIG. 9 is schematic perspective view of a first example configuration of a spring band of the diaphragm of FIG. 8.
FIG. 10 is another schematic perspective view of the diaphragm of FIG. 8 shown with the spring band of FIG. 9 being visible in the rim of the diaphragm.
FIG. 11 shows a section of the spring band of FIG. 9 that is generally positioned in region B of FIG. 9.
FIG. 12 shows a section of the spring band of FIG. 12 that would generally be positioned in side region C shown in FIG. 9.
FIG. 13 shows a section of a second example configuration of a spring band for a section that would generally be positioned in region B shown in FIG. 9.
FIG. 14 shows a section of a second example configuration of a spring band for a section that would be positioned in anterior region C shown in FIG. 9.
FIG. 15 shows a section of the spring configuration of FIG. 14 that would generally be positioned in region A shown in FIG. 9.
FIG. 16 is a close view of a central portion of the spring band section of FIG. 14.
FIG. 17 is schematic perspective view of a third example configuration of the spring band of FIG. 8.
FIG. 18 is a close view of a section of the spring band of FIG. 17.
FIG. 19 illustrates a method for manufacturing the diaphragm spring of FIG. 17 according to aspects of the invention.
FIG. 20 is a cross-sectional view taken along line Y-Y of FIG. 19.
FIG. 21 illustrates anticipated stress concentrations during insertion of the spring band of the diaphragm of FIG. 8.
The figures referred to above are not drawn necessarily to scale and should be understood to present a simplified representation of the invention, illustrative of the basic principles involved. Some features of the diaphragm depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Diaphragms, as disclosed below, can have configurations and components determined, in part, by the intended application and environment in which they are used.
DETAILED DESCRIPTION OF THE DRAWINGS
Unless otherwise stated, or otherwise clear from the context below, directional references used here are based on the orientation of components and assemblies shown in the appended drawings.
FIG. 8 shows an embodiment of a contraceptive or non-contraceptive diaphragm 102 according to aspects of the invention. Diaphragm 102 is similar to the configurations of diaphragms 2 disclosed in U.S. Pat. No. 5,771,900 issued on Jun. 30, 1998, which is incorporated herein by reference, except as discussed hereafter. However, it is understood that diaphragm 102 could be a contraceptive diaphragm or a non-contraceptive diaphragm. Further, it is understood that aspects of the invention could be used with both contraceptive and non-contraceptive diaphragms. For instance, diaphragms according to aspects of the invention could be provided for preventing sexually transmitted infections (STIs) and sexually transmitted diseases (STDs), collecting cervical fluid (menses collection), delivering a microbicide for STI prevention, delivering other medications to the cervix (e.g., cervical cancer treatment medications), delivering sperm to the cervix as part of artificial insemination procedures (human and animal), etc.
Diaphragm 102, having anterior portion 104, posterior portion 106, and lateral portions 105, 107, comprises a rim 108 which defines a loop that surrounds a membrane 110 and a cervical dome 112. Membrane 110 is preferably attached to rim 108 such that the plane of membrane 110 is substantially normal to rim 108 along its periphery. Although the membrane is relatively flat, it has some contour on account of its attachment to the rim which, as described below, has a curvilinear construction. The use of such a thin membrane composed of an elastomeric material enables the membrane to be extremely compliant in order to better cling to vaginal tissues when in use. Nevertheless, due to its thin construction and contoured shape, the diaphragm does not develop an overly aggressive suction.
Cervical dome 112 is a cup-shaped member which extends downwardly from membrane 110 in the posterior portion 106 of diaphragm 102. In an alternative configuration, the cervical dome may be offset slightly from the rim to aid the engagement of the diaphragm 102 with the posterior fornix. In either configuration, the dome opens upward to be received over the cervix and close the cervical os. Membrane 110 and dome 112 are preferably formed of silicone, but other suitable materials such as thermoplastic elastomer (TPE), latex, or urethane could be used. As shown, the anterior portion can include a flattened region 103, which improves contact with the vaginal wall during use to provide additional security created by this contact.
Rim 108 forms a loop which is preferably substantially elliptical in shape when viewed from above. As can be seen in FIG. 9, the profile of rim 108 is not planar like that of a standard diaphragm. Rather, rim 108 has a curvilinear construction with changing radiuses in an axial direction. In one construction, rim 108 conforms to the shape of a conic projection. Rim 108 along anterior portion 104 of the diaphragm has a centerline contour which curves slightly upwardly thereby reducing interference with the partner and relieving pressure on the urethra that may occur with a standard round, planar ring rim. Rim 108 along posterior portion 106 can have a centerline contour which curves slightly downwardly thereby providing for better fit in the fornix surrounding the proximal portion of the cervix. The contours of the rim 108 allow the lateral anterior quadrants of the diaphragm 102 to securely engage supportive tissue in the vagina via shallow embedment in the vaginal wall adjacent to supportive muscle or connective tissue. The gentle arcs of the rim along anterior and posterior portions 104, 106 also provide better engagement, or clinging, of the thin membrane 110 to the vaginal tissue.
A single diaphragm 102 can replace five or more sizes of standard diaphragms since its shape and construction allows it to advantageously conform and cling to the anatomy of the vagina. The diameter, or size, of one preferred embodiment of diaphragm 102 is 70 mm which would typically fit women who use standard diaphragms having sizes of 65 mm to 85 mm.
Diaphragm 102 has a reduced bulk when compared to standard diaphragms due to the fact that cervical dome 112 extends from only the posterior portion 106 of the diaphragm whereas the domes of a standard diaphragm extends across the entire rim. The reduced bulk and contoured shape of diaphragm 102 advantageously aid overall handling, increase reliability, reduce stress on the cervix when in position, make the diaphragm easier to store and more inviting to wear, increase partner acceptability, and ease insertion and removal of the diaphragm into and from the introitus. Such a construction also lowers production costs due to the reduced volume of material used.
Diaphragm 102 can also include a cup shaped projection or finger dome 116 opening downwardly from membrane 110 in the anterior portion 104 of the diaphragm. Finger dome 116 is provided to ease removal of the diaphragm. Finger dome 116 can be located adjacent the anterior vaginal wall slightly behind pubic bone such that it can be easily grasped or hooked with a finger for removal. Also, since the finger dome is composed of pliable material, the dome tends to collapse and thereby conform to the woman's internal anatomical structure. As discussed above, the upwardly curving anterior portion 104 lifts rim 108 helping to avoid an obstruction for the wearer's partner and relieving pressure on the urethra. To remove diaphragm 102, a finger is inserted into finger dome 116 and the diaphragm is then pulled from the vagina. This embodiment may provide less interference with vaginal anatomy in smaller size vaginas, i.e., those of women normally wearing 60 mm to 70 mm diaphragms. As shown, the finger dome may be placed offset from the anterior centerline proximate flattened region 103.
As further shown in FIG. 8, small dome shaped projections 120 may be provided along a portion of lateral portions 105, 107 of rim 108. Projections 120 preferably have a height of 0.5-2.5 mm and a diameter of 1.0-3.0 mm, and are most preferably 1.0 mm high with a diameter of 2 mm. Projections 120 provide a tactile indication of the optimal location for grasping the diaphragm 102 as well as improved grip when inserting the diaphragm into the vagina, especially when it is made slippery by the application of spermicide, gel or other lubricants.
When inserting diaphragm 102, which is generally illustrated in FIG. 6 using similar diaphragm 2, it is grasped about lateral portions 105, 107 and squeezed. The bending dynamics caused by the contoured shape of rim 108 and the selected bending dynamics discussed below for spring band 109 changes the shape of diaphragm 102, thereby optimizing the shape of the diaphragm for insertion. Its squeezed shape is more stable and the leading edge for insertion, that is posterior portion 106, is bent downwardly even more so that it more easily passes the anterior aspect of the cervix as the diaphragm is nestled into place. The bending dynamics of spring band 109 allows diaphragm 102 to flex at desired hinge locations thereby reducing the profile of the diaphragm and making its insertion less noticeable and making its deployment within the vagina more effective. Once the diaphragm 102 is in place, spring band 109 restores diaphragm 102 to its original shape.
Rim 108 preferably includes an engineering thermoplastic or thermoset polymeric material spring band 109 that acts as a spring member to improve insertability of the diaphragm and to improve retention of the rim in its contoured configuration. In general, polymeric band 109 provides the functional advantages as the assembly of bands 22 and spring 24 discussed in U.S. Pat. No. 5,771,900. However, polymeric band 109 provides a spring member that has various additional advantages as described herein, such as increased design flexibility, improved manufacturability, and reduced cost. As shown in FIGS. 9 and 11-18, spring band 109 can have a generally elliptical or oval cross-section. The orientation, thickness and other characteristics of its elliptical cross-section can change along its length to provide varying bending and spring characteristics. The configurations shown in FIGS. 9 and 11-18 have been prototyped and tested for strength and stiffness as well as other bending characteristics. FIG. 21 shows the results of finite element analysis calculations for spring band 109 when the diaphragm is in a folded insertion configuration similar to the configuration shown in FIG. 6. The areas shown in red are high stress areas and the areas in yellow/green are moderate stress areas.
Spring band 109, formed as a polymeric member, has varying geometries that provides varying spring characteristics. The use of an elastomer to form spring band 109 provides advantages such as permitting the spring band to have a desired contour and to have varying geometries. FIGS. 9 and 11-18 illustrate various polymeric spring bands 109 having different configurations. However, each of these configurations has anterior and posterior sections 106 and 103 that are canted according to the desired contour of the diaphragm 102.
The configuration of FIGS. 9 and 11 has an elliptical cross section that is uniform in both size and orientation along its length. Such a configuration is relatively easy to manufacture due to its uniformity. However, it lacks the ability to favor bending in certain areas and in particular directions and to provide increased spring force in other areas.
The configuration of FIGS. 12 and 13 illustrates a second example configuration in which the cross sectional width at the anterior section 106 and the posterior section 103 (FIG. 9) are tapered to be half the cross sectional width of the lateral portions 105 and 107. As such, the anterior and posterior sections bend more easily than the lateral portions to encourage the diaphragm to fold together into an insertion configuration similar to the configuration shown in FIG. 6. The improved bending at the anterior and posterior sections reduces stress values in the high stress areas shown in FIG. 21. As further shown, the orientation of the ellipse can change (e.g., twists) to improve bending and resiliency in certain directions at varying points along the band. For instance, the ellipse is vertically oriented at the anterior and posterior sections so that it can more easily bend at the thinner portion of the ellipse.
The configuration of FIGS. 14-16 illustrates a third example configuration in which the anterior portion of the spring band necks down to have a thinner elliptical cross section at a desired bending location. FIG. 16 shows a portion of the band where it necks down to form an elongated ellipse. The necked down portions in the anterior and posterior sections permit the spring band to easily bend at those portions during insertion of the diaphragm. In addition, the oval cross-section at the anterior and posterior sections can provide for improved mold manufacturability since larger radius cutting tools can be used to cut the spring profile into the mold.
FIGS. 17 and 18 show a fourth example configuration of spring band 109, which is generally a preferred configuration for use with diaphragm 102. The spring band in this configuration is generally the same as the spring band shown in FIGS. 14-16, except that area B has elongated cross sections such that the length of their elliptical cross sections are longer than the length of the cross sections to either side (e.g., cross section A). The elongated sections provide larger hinges to improve fatigue life of the spring band.
The configuration of FIGS. 17 and 18 provide a spring band having a constant cross section A along its sides whose area moment of inertia creates a stiff region along that portion of the spring band. It also has a constant cross section B at the ends whose area moment of inertia creates a flexible region along the spring to promote the majority of bending in this region. Both cross section A and B are oval with a major axis and a minor axis. Thus the moment of inertia at any given point along the spring favors greater bending in one plane of the cross section than the other. Additionally, there is a transition region between cross sections A and B through which the cross section maintains an oval shape, but the major and minor diameters smoothly transition from cross section A to B or vice versa. The orientation of the oval at any given point is chosen to promote specific bending properties of the diaphragm to aid with easy insertion and removal and to provide a comfortable fit.
In general, spring band 109 has a varying cross section, which influences the bending dynamics of rim 108. As discussed above, spring band 109 can be a non-circular, non-coiled, continuous, non-planar hoop with oval cross-sections of varying major and minor diameter. Spring bands according to aspects of the invention described along with the above configurations provide various advantageous bending properties. For example, improved bending at the anterior portion can permit the diaphragm to be relatively small at the end inserted into the vagina to, thereby, promote easy insertion. Therefore the radius of the forward edge of the diaphragm when bent is relatively small, but is blunt enough to avoid inducing discomfort or injury. In addition, the insertion and removal ends of the diaphragm are permitted to drop when the diaphragm is squeezed for insertion to create a streamlined device for insertion. When the diaphragm unbends in the vagina, the spring band 109 induces forces on the rim and within the vagina to promote a secure fit of the device such that the diaphragm dome covers the cervix, the insertion end is tucked into the posterior fornix and the removal end is tucked behind the pubic bone.
Spring band 109 can be formed from a variety of polymers having appropriate characteristics, such as biocompatibility, strength, stiffness, and elongation. For example, the spring can be formed from injection molded or cast medical-grade silicone rubber, nylon, acetal, polyphenylsulfone, PET, PBT or other suitable material. Suitably robust materials can be selected based on biocompatibility, polymer class, manufacturing temperatures, flexural modulus, fatigue resistance and elongation at yield. The preferable material for spring band 109 is a Nylon 6,6 known as SOLUTIA VYDYNE 21SP. This resin was selected as the preferred material for use with diaphragm 102 based on the criteria above and the results of the following tests using this material with the above described configurations of spring band 109.
- Short axis compression: the diaphragm sides were compressed on a force/displacement test machine in a manner similar to that used during insertion into the vagina.
- Long axis compression: the diaphragm anterior and posterior sections were compressed on a force/displacement test machine to simulate forces exerted on the device by the posterior fornix and pubic arch while the device is in the vagina.
- Resistance to boat bending: the stability of the device or resistance to unacceptable bending that might lead to incomplete cervical coverage when the device is in the vagina was assessed.
- Kneel-down performance: the dynamic behavior of the anterior and posterior, which ideally “kneels” or drops down during short axis compression to promote easier insertion was assessed.
- Relaxation behavior: the material properties of the spring and resistance to creep over time when under a load was assessed.
- Water absorption: Since the diaphragm device would be subjected to periodic cleaning, tests were conducted to determine to what extent water absorption affected the spring performance.
FIGS. 19 and 20 illustrate a method for manufacturing spring band 109 in accordance with the invention. As shown in FIG. 19, a series of segmented spacers 160 are molded onto the spring band prior to its final over-molding in the diaphragm tool. The configuration of these spacers, including the number of spacers and their shape, can be varied as desired. The shape and number of these spacers are preferably sufficient to promote centering of the spring band cross section within the rim cross section and to promote adequate flow of liquid silicone resin between segments. FIG. 20 shows one preferred configuration of the spring band, spacer and rim. As shown, the configuration includes a preferred gap of 0.01 inches or more between the rim and the inside of the mold, which provides a rim thickness of 0.01 inches proximate to the spacers.
In light of the foregoing disclosure of the invention and description of certain preferred embodiments, those who are skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the true scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.
Patent Application
20070289598
