while this invention may be embodied in many different forms , there are described in detail herein specific preferred embodiments of the invention . this description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated . for the purposes of this disclosure , like reference numerals in the figures shall refer to like features unless otherwise indicated . in fig1 a side view of an embodiment of a distal member 8 of the invention is shown . here the sheath 10 covers a stent 12 having a first guidewire 14 and a second guidewire 16 passing through it . such a stent 12 can be used in a vessel bifurcation . in some embodiments the distal member 8 is advanced along two guide wires 14 and 16 . the first guidewire 14 is positioned in the primary passage or branch vessel and the second guidewire 16 diverges from the first guidewire 14 upon passage into the secondary branch in the region of the bifurcation . as the distal member 8 approaches the bifurcation , the sheath 10 may then rotate so as to be aligned with the side wall passage at the bifurcation . the sheath 10 has a slit 18 which allows the sheath 10 to be retracted without first removing second guidewire 16 . the sheath 10 is engaged to stent sheath clutch housing 15 . the different embodiments of the mechanism 15 are shown in detail in later figures . in at least one embodiment the sheath 10 is retracted before the stent 12 is deployed . in fig2 a partial top down view of the catheter assembly 8 shown in fig1 is illustrated . here the stent 12 has a special cell 20 that provides structure through which another medical device may pass . in at least one embodiment , the special cell 20 may extend at an oblique angle into the bifurcation . due to the loads on the slit 18 in the sheath 10 , in some embodiments it may be desirable to provide the slit with a variety of configurations . for example , in the embodiment shown in fig3 , the slit 18 has a substantially s - shaped configuration . such a substantially s - shaped slit may prevent the stent 12 from trying to force itself into a non - round position beneath the sheath 10 . the substantially s - shaped slit 18 may comprise a variety of different shapes , lengths , and configurations . for example , in the embodiment shown the slit 18 comprises two peaks 22 and valleys 24 . the magnitude of the peaks and valleys may be substantially similar . however , in some embodiments a far greater number of peaks 22 and valleys 24 may be beneficial . additionally , in some embodiments a far wider array of magnitudes for both the peaks and / or valleys may be beneficial . in some embodiments the slit 18 may be held together with a holding member 26 . in some embodiments it may be beneficial to provide the slit 18 with a variety of holding members . in some such embodiments hook and loop material , snaps , buttons , screws , adhesives , and / or magnetic material , etc may be used as the holding member 26 . for example , in the embodiment shown in fig4 , the holding member 26 is a thread which can lace the edges of the slit together and can be unraveled prior to the pulling of the sheath 10 or as the sheath 10 is being retracted . in other embodiments the slit 18 of the sheath 10 may have spiraled configurations . one such embodiment is shown in fig5 . in order to retract the sheath 10 it may be useful to employ a “ smart ” manifold and a small clutch to rotate the sheath 10 off at the same pitch of spiral as that of the spiral slit 18 . it may be beneficial in some embodiments to combine the substantially s - shaped slit or the spiral slit of with the lacing of fig4 . in some embodiments the slit 18 may be unnecessary . for example , in the embodiment shown in fig6 the stent may be of the sort illustrated having a pant leg design . the stent 12 has two longitudinal portions wherein the first longitudinal portion 12 a is disposed about first guidewire 14 along the length of first longitudinal portion 12 a and second longitudinal portion 12 b is disposed about second guidewire 16 along the length of second longitudinal portion 12 b . in this embodiment the stent may have a self expanding pant design . here , there is a single sheath 10 covering the stent 12 and longitudinal portions 12 a and 12 b . the second longitudinal portion 12 b of the stent 12 is disposed about second guidewire 16 while the first longitudinal portion 12 a of the stent 12 is disposed about first guidewire 14 passing through the tip of the stent end of the delivery system 28 . in some embodiments the sheath 10 is split into a proximal sheath portion 10 a and a distal sheath portion 10 b as illustrated in fig7 . the distal sheath portion 10 b may be moved distally while the proximal sheath portion 10 a may be moved proximally , thus allowing the stent 12 to expand from the center of the stent 12 to the ends of the stent 12 rather than from one end of the stent 12 to another ( e . g . from the distal end to the proximal end ). in fig8 an embodiment of the invention is shown wherein the sheath 10 is disposed over the distal member 8 of the catheter assembly . though many geometrical shapes may be used , in at least one embodiment the stent sheath clutch housing 15 is oval shaped and has a magnetically attracted surface . the clutch housing 15 may be able to rotate about the catheter assembly . the distal end of the proximal member 32 comprises a magnetic configuration 34 which may be able to rotate . in this embodiment when an electric current is applied to the configuration 34 substantial magnetic properties may be produced and the distal end of the proximal member 32 engages stent sheath clutch housing 15 of the distal member 8 such that the stent sheath 10 may be retracted by retracting the proximal member 32 . proximal member 32 and the distal member 8 are shown engaged in fig9 . the magnetic attraction between stent sheath clutch housing 15 and magnetic configuration 34 substantially disappears when current is no longer flowing to the configuration 34 . in some embodiments , the configuration 34 may also be a permanent magnet . in at least one embodiment the proximal member 32 and stent sheath clutch housing 15 may be advanced with a barrier member 36 between them . when the barrier member 36 is removed the attractive forces between the clutch housing 15 and the configuration 34 on proximal member 32 may be capable of retracting stent sheath 10 upon moving the proximal member 32 in a proximal direction . in at least one embodiment the distal member 8 may have a clutch housing 15 of a looped wire ( metallic or polymer ) ring and / or a metallic or polymer locking ring which may consist of a band disposed inside or outside distal member 8 . at least one embodiment is shown in fig1 where a looped wire ring may be included . the hooks 38 of fig1 may be attached to grappling base 39 which can be pushed forward by distal movement of push / pull wire 40 . the hooks 38 may be extended distally beyond the distal most portion of proximal member 32 and engage the clutch housing 15 of distal member 8 . once engaged as illustrated in fig1 , proximal movement of the proximal member 32 or proximal movement of push / pull wire 40 may retract sheath 10 . in at least one embodiment , as shown in fig1 , the clutch housing 15 may have hooks 42 which can be restrained from extending proximally with an intervening device or barrier member 36 as in fig1 . the clutch housing 15 having hooks 42 may be of a shape memory material that returns to an original extended shape upon heating . for example , when the hooks 42 are heated by the warmth of the body lumen or by electrical resistance they may extend proximally from clutch housing 15 . the clutch housing 15 in at least one embodiment may have hooks 42 which are magnetically attracted to extend proximally towards the proximal member 32 . this may comprise an electrically induced magnetic attraction . a pullwire may also be used to pull the hooks 42 proximally from the clutch housing 15 . in all instances above , the hooks 42 are intended to engage the proximal member 32 through proximal member engagement mechanism 44 arranged about the opening of the proximal member 32 . the mechanism 44 in some embodiments may be wire loop rings arranged about the distal opening of the proximal member 32 or a lock ring arranged about the distal opening of the proximal member 32 as shown in fig1 and 16 . in at least one embodiment a distal member 8 has a through hole 46 . for example , the distal member 8 of fig1 illustrates at least one embodiment . proximal member 32 may be positioned such that inner clutch extension 48 extends into through hole 46 . for example , at least one embodiment is shown in fig1 . inner clutch extension 48 may have expanding fingers 50 on its distal end . the distal member 8 may rotate around the expanding fingers 50 much like bearings . as shown in fig1 , upon the inner clutch extension 48 being advanced distally , the fingers 50 may expand such that proximal retraction of the inner clutch extension 48 may retract the sheath 10 as well . as illustrated in fig2 , the clutch extension 48 may comprise an inflation lumen 52 for inflating balloon 54 . before insertion into the through hole 46 the balloon 54 may be partially inflated or the balloon may be deflated in order for the clutch extension 48 to pass through through hole 46 . upon insertion , the balloon 54 may be inflated thereby inhibiting the proximal motion of clutch extension 48 in relation to through hole 46 . thus , proximal motion of the clutch extension 48 may result in the sheath 10 being retracted . it should be noted that most of the clutch mechanisms described in this application may be preassembled such that the proximal member 32 and the distal member 8 are in the engaged state . the distal member 8 may rotate about the clutch extension 48 with pullback means being necessary without the need for a corresponding push means . this is illustrated in fig2 wherein pullback apparatus 56 may not pass through through hole 46 after assembly . it should be recognized that fig2 illustrates only a generic pullback apparatus 56 . all of the embodiments in this application may be of the type where substantial movement of the proximal member 32 in relation to clutch housing 15 is inhibited . this invention includes the use of balloon expandable stents . though the use of a sheath has application with balloon expandable stents , in at least one embodiment a sheath is not necessary . as illustrated in fig2 the stent 12 may be disposed about balloon 58 without a sheath . the balloon 58 may be free to rotate about clutch extension 48 in order to better place and deploy the stent . use at bifurcations is at least one application of this invention . the balloon 58 may be sealingly engaged to the clutch extension 48 at the distal and / or the proximal portions of the balloon 58 . in fig2 proximal expandable seal 60 and distal expandable seal 62 are at least partially uninflated . upon positioning the stent 12 the balloon 58 and clutch extension 48 may be moved together proximally by inflating the proximal expandable seal 60 and / or the distal expandable seal 62 . the inflated state is shown in fig2 . it should be noted that the balloon 58 may rotate in this inflated state . in some embodiments , as in fig2 and 23 , the clutch extension 48 does not have the proximal member 32 disposed about it at the distal portion of the proximal member 32 . in some embodiments the proximal member 32 may be disposed about clutch extension 48 and may extend distally to the proximal end of balloon 58 and in some embodiments be disposed about balloon 58 and stent 12 . in some embodiments , as in fig2 and 23 , the clutch extension 48 has diameters which are unequal at the proximal contacting balloon section 64 and the distal contacting balloon section 66 . in some embodiments , clutch extension 48 may be of the substantially same diameter at all locations on the member 48 and longitudinally aligned along all portions of the member 48 . in some embodiments , the proximal contacting balloon section 64 and the distal contacting balloon section 66 may have substantially similar diameters . in some embodiments different lumens may be used in inflating the balloon 58 , the proximal expandable seal 60 , and / or the distal expandable seal 62 . in some embodiments the balloon 58 , the proximal expandable seal 60 , and the distal expandable seal 62 may also share one or more inflation lumens . the above disclosure is intended to be illustrative and not exhaustive . this description will suggest many variations and alternatives to one of ordinary skill in this art . all these alternatives and variations are intended to be included within the scope of the claims where the term “ comprising ” means “ including , but not limited to ”. those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims . further , the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims . for instance , for purposes of claim publication , any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction ( e . g . each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims ). in jurisdictions where multiple dependent claim formats are restricted , the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent - possessing claim other than the specific claim listed in such dependent claim below . this completes the description of the preferred and alternate embodiments of the invention . those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto .
a catheter assembly has an engaged state and an unengaged state comprising a proximal member having a longitudinal axis and a distal member having a longitudinal axis . a distal end of the proximal member is removably engageable to the distal member . the distal member has a first distal portion and a second distal portion , and the first distal portion is retractable from the second distal portion . in the engaged state the distal member is substantially freely rotatable about its longitudinal axis and in relation to the proximal member . in the engaged state the proximal member is constructed and arranged to be moved in a direction along the longitudinal axis such that proximal movement of the proximal member retracts at least the first distal portion of the distal member from at least the second distal portion .