as shown in fig1 , the occluder 1 comprises a cap 2 , a body 3 , attachment device 4 and plug 5 . cap 2 is provided with through hole 6 . as shown , the body is in an extended , stressed condition and expansion means 4 is in a collapsed condition . fig2 shows occluder 1 with attachment means 4 in their expanded configuration after the lengthening stress on body 3 has been removed . as can be seen in a comparison of fig2 with fig1 , the lengthening of body 3 is accomplished by exerting axial force on plug 5 . when that force is removed , plug 4 assumes its unstressed shorter configuration as shown in fig2 and plug 5 moves into through hole 6 such that there is no longer an opening in cap 2 . the body 3 may be made of nitinol metal while cap 2 and plunger 5 may be made from a suitable polymer material . fig3 shows the occluder in combination with a delivery means comprising grasper 7 and plunger 8 . in the configuration shown in fig3 , plunger 8 pushes on plug 5 to cause the body 3 to assume its extended , stressed configuration and causes grasper 7 to engage cap 2 . as shown in fig4 , when plunger 8 is retracted , body 3 shortens and attachment members 4 assume their expanded configuration . this shortening of body 3 moves plug 5 into the through hole 6 in cap 2 . fig5 shows the occluder device after installation with attachment means 4 engaging the wall of fallopian tube 9 and cap 2 sealing the fallopian tube at uterus wall 10 . once deployed , the device achieves virtually instant sterilization . an alternate embodiment of the occluder device of the present invention is shown in fig6 . in this embodiment , the occluder device has a distal portion which is the occluder element and a proximal portion which is the fixation element . the occluder element comprises a tubular portion 11 which is preferably fabricated from a soft polymeric or elastomeric material which has a distal end region 12 with a relatively narrow diameter . located proximally to the distal region 12 are a series of spaced ribs 13 - 16 which have progressively increasing diameters . the portion of the occluder element extending from the narrow diameter tip to the largest diameter rib 16 may be hollow or solid . the number of ribs shown in fig6 is exemplary only and there may be a lesser or greater number of ribs . each of the ribs plays a role in occluding a fallopian tube , but the largest diameter rib is the primary occluding element . a fixation element 17 which has a distal portion 18 and a proximal portion 19 extends from a point proximal to the proximal end of the occlusion element 11 to a point in the region of the distal end of the occluding element , typically in the region of ridge 16 . the distal end 18 of the fixation element may comprise an enlarged loop as shown in fig6 or may have any other suitable configuration . a proximal portion 19 of the fixation element 17 preferably bows outwardly as shown in fig6 with a straight portion 20 proximal to the bowed portion 19 . as will be described in more detail below , the bowed portion 19 of the fixation element is fabricated from a resilient or elastic material which can be deformed such that it is in alignment with straight portions 20 when constrained by a sleeve ( not shown ) and which will revert to its bowed configuration when the constraint is removed as shown in fig6 . optionally , a tissue - engaging element 21 can be attached to the bowed portions 19 . for example , the fixation device may have the configuration of a flared cylinder as shown in fig6 or it can have other configurations such as a barb , hook , or other projection including the type shown as element 4 in fig2 hereof . fig7 illustrates an occlusion device similar to that illustrated in fig6 and the same reference numerals are used for the same elements . however , in fig7 , the illustrated embodiment has a fixation element comprising two looped wires rather than one looped wire as shown in fig6 . fig8 is a cross - sectional view of fixation enhancing attachment 21 which has flared ends 22 . deployment of the occlusion devices of fig6 and 7 is accomplished by using a delivery device comprising two sleeves , an inner sleeve or tube which abuts the proximal end of occlusion element 11 and which constrains the bowed portions 19 of fixation element 17 such that they are aligned with proximal portions 20 . a second outer sleeve or tube is positioned over occlusion element 11 and over the inner sleeve such that the distal end of the outer sleeve abuts the largest diameter rib 16 . the outer sleeve is attached to a handle and is flexible . preferably , the occlusion device is deployed in conjunction with the use of a hysteroscope which permits visualization of the target fallopian tube and which has a separate lumen adapted for delivery of the occlusion device . thus , by first visualizing the fallopian tube and then manipulating the handle attached to the outer tube of delivery device , the occlusion device can be inserted into the fallopian tube such that , preferably , the insertion is deep enough for the proximal end 20 of the fixation device to be located within the fallopian tube . the outer and inner tubes are then removed such that the outer tube no longer contacts the occlusion device and such that the bowed portions 19 of the fixation element 17 are free to bow outwardly into contact with the tissue of the fallopian tube . if the optional fixation elements 21 are used , they will also be brought into contact with the tissue of the fallopian tube . as with the device shown in fig1 - 5 , the occlusion device of fig6 and 7 will immediately occlude the fallopian tube such that the waiting time associated with other fallopian tube occluders before they are effective in occluding a fallopian tube is not required . the fixation element 17 can be made out of any suitable resilient or elastic material which may be either metal or polymeric , e . g ., metals such as nitinol , stainless steel , plastic , reinforced plastics or other suitable materials may be used . among the polymeric materials which may be used are included polyimides , polyolefins , polycarbonates , polyesters , polyamides , polyurethanes , synthetic rubbers , etc . similarly , the occlusion element can be made from a wide variety of materials . preferably , this element is made from a relatively soft material which may be rubber , synthetic rubber , a foam material which may be fabricated from the polymers identified above or from other materials . the occlusion element may also be made from metal , but a non - metal material is preferred for most uses . furthermore , a material may be added to the outside of the occlusion element which will promote scarring , typically by physical irritation of the fallopian tube tissue or by other scarring mechanisms which may include chemical compounds , to further insure the integrity of the occlusion of the fallopian tube . shape - memory metals or polymers are preferred for fabricating the fixation element 17 . these shape - memory materials may be composites , e . g ., polymers which contain particulate or other additives , such as carbon particles or fibers , and may be combinations of metal and polymer , such as a coated metal . the shape memory may be temperature dependent , i . e ., actuated by heating or other energy input , or may be mechanical in nature . such materials are well known to those skilled in the art . fig9 is a schematic illustration of the delivery system of the present invention . as shown , inner tube 24 compresses the bowed portions 19 of the fixation element such that the bowed portions are aligned with the proximal portions 20 . outer sleeve 25 functions as a pusher element and is connected to a handle ( not shown ). the outer sleeve 25 is dimensioned so that it will fit in the additional lumen in a hysteroscope and , when pushed distally by applying force to the handle to which it is attached , will advance the occluding element into the fallopian tube . once the desired location is achieved , outer sleeve 25 is removed . at this time , inner sleeve 24 which abuts the proximal end 23 of the occlusion element is also removed by pulling it in a proximal direction . when inner sleeve 24 is removed , bowed portion 19 of the fixation element will expand outwardly into the tissue of the fallopian tube to effectively hold the device in place . fig1 a - c are sequential schematic drawings which further illustrate delivery of the occlusion device . in these drawings , fig2 is a handle which slidably receives outer sleeve 25 . when trigger 27 is pulled , it slides outer sleeve 25 proximally away from the occlusion device to deploy it in the fallopian tube . inner sleeve 24 is then also moved proximally to release bowed portions 19 of the fixation element as shown in fig1 c . fig1 is a schematic illustration of the occlusion element 11 deployed in fallopian tube 28 with the bowed portion 19 of the fixation element engaged with the tissue of fallopian tube 28 . in actual practice , the bowed portion 19 of the fixation element would penetrate the fallopian tube tissue and the occluder element would be large enough to cause the contour of the fallopian tube to be altered to be in a satisfactory degree of confirmation to the shape of the occluder device to assure effective occlusion . the foregoing description of specific embodiments exemplifies the present invention and is but one embodiment thereof . thus , it is to be understood that the scope of this invention is defined solely by the appended claims .
occlusion devices and methods for occluding fallopian tubes which take effect promptly after deployment . the occlusion means comprise an occluding element and a fixation element . in one embodiment , the occluding element is deployed within the fallopian tube and in another embodiment , the occluding element is external to the fallopian tube .