FR2529079A1 - Endo uterine contraceptive - has arms with non injurious ends folding elastically above and below stem - Google Patents

Abstract

The contraceptive comprises a central stem (1) and two lateral elastic arms (4,5) symmetrical in relation to it, bearing against the endo-uterine walls and secured to the top end (1a) of the stem. In their extended anchoring position, the arms are generally S-shaped having a smaller outer (4b,5b) radius of curvature than their radius of curvature towards the central stem. The free ends of the arms are non-injurious and can be folded elastically towards each other, both above and below the top end of the stem. In the latter position they can cross over each other, so as to fit with the stem in a small-diameter insertion tube (6).

Description

STERILET WITH FOLDING SIDE PRAS FOR TWO ENDS OF A TIGECENTRAL
The present invention relates to a steri # and of the type comprising a central rod and a device intended to bear on the endo-uterine walls of a subject, in order to hold the central rod in place, device composed of two elastic, symmetrical lateral arms with respect to the rod of which they are integral at its top while its base is free.

 IUDs of this type that currently exist all have drawbacks because none to date has managed to reconcile the contradictory needs inherent in their use.

 Indeed, an IUD must, by nature, remain in place in the uterine cavity for long periods and must, therefore, resist contractions and other stresses to expulsion.

 However, at the same time, an IUD should be able to be removed as simply as possible, without causing pain or internal injury while avoiding the need for dilation of the cervix.

 Among the known IUDs, there are some which have a rectilinear central rod and two lateral arms which are also substantially rectilinear which give the assembly a general "T" shape.

 There are also some which have a central rod and a single transverse arm which join at one end of the latter, giving the whole IUD a general shape in "7".

 The insertion and removal of these IUDs is simple and without serious danger, but both are supported on the endo-uterine cavity by the ends of the arm (s) so that there is a definite threat of injury to the endometrium and even of the myometrium.

 It is indeed logical to consider as a necessity to provide for the IUD support points on the endo-uterine cavity having the largest possible area so that any effort between the IUD and this wall is distributed over a large area avoiding the risks of perforation.

 there are, moreover, IUDs whose shapes are curved according to very diverse configurations which go from the perfect circle to complex configurations through the simple spiral.

 These curved shapes along fairly large radii obviously do not present any danger of injury when the IUD is in place.

 But, on the other hand, they present very serious difficulties of installation and withdrawal due to their dimensions, unless they are very easily deformable, in which case they can be accidentally expelled by the natural contractions of the uterus.

 We cannot combine the qualities of I / O or "7" IUDs and those of curved IUDs because the qualities of some do not combine with the qualities of others and we always come up against the same difficulties, either during their movement (installation and removal) or when they should remain in place, immobile.

 There is also an IUD which comprises a central rod and arms which are strongly curved towards the free end of the central rod and are provided with reliefs which have to bear on the endo-uterine wall.

 By its shape, this IUD is very effectively opposed to its accidental removal.

 But, as a direct consequence of this advantage, its removal is very difficult without damaging the internal orifice of the cervix and the cervical canal, so that its removal is considered to be injurious to the tissues of these regions by the practitioners and deemed painful by the users.

 The shape of the arms of this IUD, both in their general configuration and in the shape of their section makes it impossible to use a withdrawal tube because the arms cannot be folded one before the other beyond the top of central rod.

 The present invention, on the contrary, overcomes all of these drawbacks by making it possible to produce, in several possible variants, an IUD which has both very great ease of fitting and removal on the one hand and an excellent guarantee of holding in place on the other hand.

 To this end, the subject of the invention is an IUD of the type comprising a central rod and a device intended to bear on the endo-uterine walls of a subject, in order to hold the central rod in place, device composed of lateral arms elastic, symmetrical # with respect to the rod of which they are integral at its top while its base is free, characterized in that the arms end in a non-injuring free end and are liable to be folded one towards the other as well beyond the top of the rod as below, by placing itself over a small width, possibly crossing, so that they can both be engaged with the rod in a tube of small diameter.

According to other features of the invention
- the arms have a permanent bend, that is to say that their natural elasticity constantly urges them towards a bending position whose concavity is directed towards the central rod so that the arms are supported by bracing against the endoutine walls when the IUD is in place and that, correspondingly, the central rod is constantly stressed in the direction of their top by the elasticity of the arms.

 - the non-injurious end of the arms is constituted by a volute directed towards the outside and towards the top of the central rod.

 -the radius this curvature of the volute is sufficiently large to present an arc by which the arm is intended to bear against the endo-uterine wall when the IUD is put in place, while the end of the volute extends in a direction clearly diverging from this wall.

 - The arms have an oblong section oriented so that their smallest thickness is arranged radially with respect to the curvature that the arms must be able to take elastically, especially when they have to be folded back towards each other.

 - the arms are connected to each other on the top of the central rod and diverge upwards.

 - The arms have a variable section depending on the location of their length that is considered, the weakest section or sections corresponding to the preferred location or locations of their desired drawdown.

 The invention will be better understood from the detailed description below made with reference to the accompanying drawing.

Of course, the description and the drawing are given only by way of an indicative and nonlimiting example.

 Figure 1 shows the implementation of an IUD obtained according to a first embodiment.

 Figure 2 is a schematic view of this IUD in place. Figures 3 to 6 are schematic views showing the removal of this IUD.

 Figure 7 shows the implementation of an IUD obtained according to a second embodiment of the invention.

 Figure 8 is a view of this IUD in place.

 Figures 9 to 11 are schematic views showing the removal of this IUD.

 Figure 12 is a partial schematic view showing the particular shape of the section of the lateral arms of an IUD according to the invention.

 Referring to Figures 1 to 6, we see that according to a first embodiment of the invention, an IUD comprises a central rod I on which is wound, in known manner, a copper wire 2 and provided at its base of a transverse passage for two wires 3 intended for locating and extracting the IUD, as is known per se.

 The top of the rod 1 is integral with two arms 4 and 5, the assembly of the rod 1 and the two arms 4 and 5 being advantageously obtained by molding in a single piece of a synthetic material, so that these two arms are elastically deformable while having sufficient hold and "memory", as explained below.

 The arms 4 and 5 are not only elastically deformable but also have a length such that they are capable of being folded towards each other, both beyond the top of the rod 1 and below by placing themselves over a small width, possibly by crossing as shown in the drawing, so that they can both be engaged with the rod 1 in a removable small diameter tube 6.

 The arms 4 and 5 have a permanent bending, that is to say that their natural elasticity constantly requests it towards a bending position, the concavity of which is directed towards the central rod 1, that is to say that the upper part of the arms 4 and 5 is in the form of an arc 4a and Sa respectively.

 These arcs 4a and Sa extend to constitute a non-injurious end which is constituted by a volute 4b and 5b directed outwards and towards the top la of the central rod 1.

 The outer part of the volute 4b-5b is provided with reliefs 4c and 5c of any type known per se so as not to injure the endo-uterine wall A against which they are intended to bear.

 The radius of curvature of the scrolls 4b and 5b is large enough to present a non-injurious arc, the free end of which 4d and 5d respectively extends in a direction which is clearly divergent from this wall A.

 The installation of an IUD as just described is particularly simple and since the assembly is engaged in the tube 6 thanks to which the cervical canal 8 is passed through the IUD.

 When the assembly has been introduced sufficiently deep into the uterine cavity, the tube 6 is removed while maintaining the IUD by means of a mandrel bearing on the lower end of the rod 1a.

 In doing so, we release the arms 4 and 5 which were folded towards each other beyond the top la during the insertion, and their natural elasticity causes them to deploy as the tube 6 is removed until they take their normal shape which is shown in Figure 2.

 It can be seen in this figure that the arms 4 and 5 bear on the endo-uterine wall A by bracing and properly maintain the rod 1 in the axis of the uterus.

 The ends 4d and 5d extending in diverging directions with respect to the endo-uterine wall A, there is no fear of injury as a result.

 Similarly, the radius of curvature of the scrolls 4b and 5b is large enough for a large contact surface to be used for maintaining the IUD, this maintenance being favored by the presence of the small soft protuberances which constitute the reliefs 4c and 5c.

 Whatever the. natural contractions of the subject's uterus, the IUD is held in place.

 Indeed, if contractions or natural movements cause lateral efforts on the IUD, these are compensated for by the arms 4 and 5 which can deform elastically as they approach each other.

 If these contractions or natural movements result in a vertical force, this is absorbed by the arcs4a and Sa of the arms 4 and 5 which can easily deform but without in any way leaving their support on the endo-uterine wall A, so that such efforts would result in a very slight lowering of the rod 1 towards the cervical canal B but, as soon as this effort has ceased, the rod 1 is returned upwards by the elastic return of the arms 4 and 5 to their original position.

 It is noted that the arms 4 and 5 constitute in cooperation a holding device which tends, permanently, to recall the rod 1 towards the bottom of the uterine cavity, unless its point of equilibrium is exceeded, that is to say say that the top of the rod 1 is located lower than the support points of the volutes 4b and 5b on the endoutine wall A as will be seen below.

 Having shown that the installation and the maintenance in place of an IUD in accordance with the invention are simple and safe, we will now describe in four phases the withdrawal of such an IUD.

 Originally, the IUD is assumed to be correctly positioned and is therefore in the position shown in Figure 2.

 The practitioner has access to the wires 3 and exerts traction on them which is transmitted by the rod 1 at the top, that is to say at the point of attachment of the arms 4 and 5 so that in the first phase the IUD is in the position shown in Figure 3.

 We see that the arcs 4a and Sa are accentuated but that the top la is still above the level of the support points of the volutes 4b and 5b on the endo-uterine wall A.

The practitioner continuing to pull, the rod 1 is engaged by the internal orifice of the neck in the cervical canal
B and the top 1a of the rod 1 is located just below the levels of the support points of the volutes 4b and 5b on the endo-uterine wall A.

 This situation corresponds to the exceeding of the equilibrium position, or stable position, of the IUD which has the consequence of applying to the top of the rod I 1 the natural elastic force of the arms 4 and 5, whence it results in an automatic unfolding of these and a push on the top of the rod 1 towards its extraction.

 At the end of this phase, the IUD is in the position shown in FIG. 5 according to which the arcs 4a and Sa of the arms 4 and 5 are practically flattened one against the other.

 The scrolls 4b and 5b are still curved but we note this very important fact that the ends 4d and 5d remain divergent with respect to the endo-uterine wall A because the movement of unwinding of the scrolls 4b and 5b is done without friction, by a kind of rolling of the outer part of the scrolls on the wall A, without stress in the direction of penetration of the flesh and, on the contrary, retaining the end 4d and 5d of the arms 3 and 4 in a zone remote from the wall A.

 Continuing the traction on the wires 3, the arms 3 and 4 are forced to unwind completely, in particular by crossing as seen in FIG. 6, which has the effect of taking off the scrolls 4b and 5b from the wall A on which they were supported.

The low pressure exerted by the walls of channel B is sufficient, taking into account the natural elasticity of arms 4 and 5, to force them to flatten towards each other while occupying only one very small width making it practically insensitive to the crossing of the cervical canal B by the rod holding device 1 constituted by the two arms 4 and 5 folded over the top the
Referring now to Figures 7 to 11 we see another embodiment according to which the arms have a simpler shape which gives the entire IUD a physiognomy closer to the known IUDs called "T".

 For the purpose of consistent description, the analogous elements of this embodiment are stated in the same unit but preceded by the figure of the first ten.

 In FIG. 7, it can therefore be seen that the IUD comprises a rod 10 on which a copper wire 20 is wound and to which wires 30 are hung.

 At the top 10a of the rod 10 are two arms 40 and 50 and this assembly, after folding one against the other above the top 10a of the arms 40 and 50, is engaged in a tube 60 of small diameter which allows inserting the IUD into the uterine cavity using the same method as that described above.

 In FIG. 8, the IUD is seen in place and, as in the case of FIG. 2, the central rod 10 is held by its top 10a by two symmetrical elastic lateral arms 40 and 50.

 Here, these arms 40 and 50 are less curved than the arms 4 and 5 but still have arcs 40a and 50a which bear on the endo-uterine cavity A by volutes 40b and 50b.

 These scrolls, here also include external reliefs or festoons 40c and 50c.

 As in the previous case, the fitting is done easily because only the tube is in contact with the cervical canal B.

 Similarly, the retention in place is ensured by arching and the assembly is maintained despite various natural movements or contractions thanks to the spring effect of the arms 40 and 50.

 The top 10a of the rod 10 is located above the level of the support points of the volutes 40b and 50b on the endo-uterine walls A so that the result of any lateral contraction is directed towards the bottom of the uterus and not to the cervical canal B.

 However, the natural elasticity of the arms 40 and 50 is such that if the wires 30 are exerted a pull strong enough to overcome the elastic resistance of the arms and to pass the top 10a of the rod 10 below the level of the points support, as seen in Figure 9, we get a drawdown of the arms 40 and 50 towards each other, beyond the top 10a of the rod 10, then, continuing the traction on the son 30, a flattening of the arcs 40a and 5osa, then an unwinding of the volutes 40b and 50b by the pressure of the walls of the cervical canal B as shown in FIG. 10.

 At the end of the deliberate deformation of the arms 40 and 50, the device is in the position of FIG. 11, that is to say that it is placed in the cervical canal B and that the two arms 40 and 50 are elongated and flattened against each other without exerting any aggressive action on the walls of this B channel.

 Here again, therefore, there is an installation, maintenance and removal of the IUD which are both easy, safe and painless.

 It emerges from the above description, that the arms of the IUD according to the invention must not only have a natural elasticity but must also be able to deploy to be placed one against the other in particular beyond the top of the central rod.

 As these same arms must also have a particular curved shape according to two arcs with different convexity according to whether they are the arms themselves or the scrolls which constitute their ends, it is advantageous to favor this folding of the arms according to zones preferential.

 This is why, according to a characteristic of the invention, the arms 4 and 5 as well as the arms 40 and 50 shown in the drawing, have an oblong section oriented so that their smallest thickness e is disposed radially by relative to the curvature that the arms must be able to take when they are folded towards each other.

 Referring to FIG. 12, it can be seen that the arms are formed in a way by ribbons of rectangular section and that they are opposite one another by their greater thickness E.

 In this way, when they are folded against each other they are placed flat against flat.

 Their unfolding and their winding are facilitated and there is no fear of random distortions because they remain practically in the same plane, except for the crossing that they may have to take but this crossing has of no importance since it causes only an insignificant angular shift of the two arms in question.

 Still with the aim of facilitating the folding of the arms towards one another, it is noted that according to a characteristic of the invention particularly visible in FIGS. 8, 9 and 12, the arms 40 and 50 are connected one to the other. the other on the top 10a of the central rod 10 and diverge in rising.

 This creates a kind of initiation of folding which facilitates the flattening of the arms against each other by their greater width E.

 We understand that it is of the greatest interest to provide arms flexible enough to fold as easily as possible while being nervous enough to ensure effective retention of the IUD in place.

 In order to reconcile these two imperatives, the invention provides that the arms may have a section of variable importance depending on the characteristics which a given area of these arms must have.

 In other words, the small thickness e is greater where the arms must have a relatively energetic spring effect and is smaller where the arms must be able to be wound and unwound without resistance in order to be put in place. one against the other as flat as possible.

 In Figure 2 and in Figure 12, there is shown a thickness e1 which is the minimum thickness and which is on the one hand near the connection of the arms at the top of the rod 1 (or arms 40 and 50 at vertex 10a of the rod 10) as well as at the connection of the arms proper and of the end volutes while this thickness has its maximum value in the central zone of the arcs 4a-5a or 40a-50a.

 This provides greater flexibility in the preferred locations of the desired drawdown for the arms.

 it appears from the above description that the design of the support arms of the central rod allows their complete erasure beyond the top of the central rod without detracting from the effectiveness of holding in place when they are in the reverse position, that is to say inclined no longer beyond the top of the rod but on the contrary towards the base of the rod.

 The effectiveness of holding the end of the arms against the endo-uterine wall makes the presence of very angular reliefs or scallops unnecessary and, on the contrary, allows the replacement by relief relief reliefs with a soft profile such as those of pneumatic or with "foam" surface.

 This gives greater anti-rejection flexibility and the removal of any traumatic relief both during the period of use and at the time of withdrawal.

 The great flexibility of the arms when they are in the holding position has the advantage that the IUD no longer causes uterine expulsion contractions or pain that these contractions cause in addition pain that sometimes occurs as a result of the support too punctual or even inlays of the support points on the endo-uterine wall.

Claims (7)

 1. - IUD of the type comprising a central rod (1) and a device intended to bear on the endo-uterine walls of a subject, in order to hold the central rod (1) in place, device composed of two elastic lateral arms (4-5), symmetrical with respect to the rod (1) of which they are integral at its top (la) while its base is free, characterized in that the arms (4-5) end in a free end not offensive and are likely to be folded elastically towards each other, both beyond the top (la) of the rod (1) and below, by placing itself over a small width, possibly crossing , so that they can both be engaged with the rod (1) in a removable small diameter tube (6).  2. - IUD according to claim 1, characterized in that the arms (4-5) have a permanent bend, that is to say that their natural elasticity constantly urges them towards a bending position whose concavity is directed towards the central rod (1) so that the arms (4-5) bear by bracing against the endo-uterine walls (A) when the IUD is in place and that correlatively, the central rod (1) is constantly stressed in the direction of its top (la) by the elasticity of the arms (4-5).  3. - IUD according to claim (1), characterized in that one non-injurious end of the arms (4-5) is constituted by a volute (4b-5b) directed outwards and towards the top (la) of the central rod (1).  4. - IUD according to claim 3, characterized in that the radius of curvature of the volute (4b-5b) is sufficiently large to present an arc by which the arm is intended to bear against the endo-uterine wall (A) when the IUD is put in place, while the end (4d-5d) of the volute (4b-5b) extends in a direction which is clearly divergent from this wall (A).  5. - IUD according to claim 1, characterized in that the arms (40-50) have an oblong section oriented so that their smallest thickness (e) is disposed radially with respect to the curvature that the arms (40- 50) must take particular elasticity when they must be folded towards each other.  6. - IUD according to claim 1, characterized in that the arms (40-50) are connected to each other on the top (lOa) of the central rod (10) and diverge in rising.  7. - IUD according to claim 1, characterized in that the arms (4-5, 40-50) have a section (e) variable depending on the place of their length which is considered, the section or sections most weak (e1) corresponding to the preferred location or locations of their desired drawdown.