the current invention comprises an improved delivery system useful , for example , for delivering implantable devices . the delivery system of the invention can replace the three essentially coaxially arranged catheter components , discussed above . disclosed are novel delivery systems comprising : a first catheter shaft having a proximal end and a distal end , the proximal end having at least first and second openings , the distal end having at least one opening , and a lumen extending from the distal end opening to the at least first and second proximal end openings ; a second catheter shaft having a proximal end and a distal end , at least a portion being located within the first catheter shaft lumen and extending from the first proximal end opening to the distal end opening , the second catheter shaft having a lumen extending from a distal end opening to at least a side opening in the second catheter shaft located between the distal end and the proximal end , the second catheter shaft further comprising a floating connector located at the proximal end thereof ; a third catheter shaft having a proximal end and a distal end and being located within the second catheter lumen , extending from the distal end opening to the side opening , exiting through the side opening and extending proximally therefrom , and exiting through the second proximal end opening of the first catheter shaft ; the first catheter shaft , the second catheter shaft , and the third catheter shaft being in a substantially coaxial relationship at the distal end of the first catheter shaft ; the first catheter shaft and the second catheter shaft being in a substantially coaxial relationship at the first proximal end opening of the first catheter shaft ; and the first catheter shaft and the third catheter shaft being in a substantially coaxial relationship at the second proximal end opening of the first catheter shaft . thus , the delivery system comprises three substantially coaxial catheters at the distal end of the first catheter , and a transitional mid - section wherein the third ( i . e . the innermost ) catheter exits the wall of the second catheter . the third catheter then extends proximally along the length of the second catheter in a collateral relationship to the second catheter and in an internal relationship to the first catheter . at the proximal end of the delivery system , the first catheter terminates with at least two proximal openings . for example , the proximal end of the first catheter can terminate in a “ y - arm ” hub assembly , wherein the second catheter can exit through a first proximal opening and the third catheter can exit through a second proximal opening . in an aspect of the invention , the delivery system configuration can be described as having a first distal three - component , substantially coaxial section , a second transitional mid - section , and a third proximal section which comprises two coaxial sections . the delivery system allows the user to maintain a close , hand - to - hand spacing while executing the delivery sequence . in addition , some of the delivery steps ( required in the prior system ) can be eliminated . thus , the delivery system can be easier to use and can result in quicker delivery times . in the improved delivery system configuration , the third ( i . e ., innermost ) catheter exits through the wall of the second catheter . therefore , at least the second catheter is constrained from rotating relative to the remaining two catheters . this can prevent damage to the catheters and also prevent the catheters from becoming entangled while manipulating the second and / or third catheter ( s ). to prevent the inadvertent rotation of the second catheter , for example during the attachment of connectors ( e . g . luer fittings ) onto the proximal end of the first catheter , an anti - rotation feature is incorporated with at least one of the second and third catheters . the connector of the present invention is free to rotate ( or float ) independently of the catheter shaft . such a connector will hereinafter be referred to as a “ floating connector .” by floating connector it is meant that the connector is rotatably mounted about the catheter shaft while longitudinal constraint ( s ) is / are provided to allow the catheter to be pushed and pulled when grasping the floating connector . in an aspect of the invention the floating connector can be rotated 360 degrees or more without applying any significant torsional force to the catheter shaft . the floating connector is capable of being connected to the proximal end of the first catheter . in an aspect of the invention the floating connector is releasably attachable to the proximal end of the first catheter . in a further aspect of the invention the floating connector can be locked to the proximal end of the first catheter with an about 90 degree turn of the connector . examples of suitable longitudinal constraints include , for example , the embodiments shown in fig1 a and b , 12 a and b and 13 , discussed in more detail below . specific aspects of the invention may be better understood with reference to the figures . shown in fig1 is a delivery system 20 according to the present invention , including helex ™ septal occluder . the system 20 has a first distal three catheter , substantially coaxial section 22 , a second transitional mid - section 24 and a third proximal dual coaxial section 26 . also shown is a formed helex ™ septal occluder device 28 fully deployed from the distal three catheter section 22 . details relating to one delivery sequence of a helex ™ septal occluder device are presented below . of course , other septal occluding devices could be delivered using the delivery system of the invention . in an aspect of the invention the septal occluding device comprises polytetrafluoroethylene and metal wire . in a further aspect of the invention the polytetrafluoroethylene is expanded polytetrafluoroethylene and the wire is a nitinol wire . one delivery system according to the present invention is displayed in fig2 . shown is a general delivery system 30 defining three cross - sectional planes . a first cross - sectional plane 3 intersects a first distal , three - catheter , substantially coaxial section ; a second cross - sectional plane 4 intersects a second transitional mid - section ; while a third cross - sectional plane 5 intersects a third proximal dual coaxial section at the y - arm hub assembly . also shown are first proximal end 38 and second proximal end 40 of a y - arm hub assembly . fig3 through 5 show details of the system along these cross - sectional planes . shown in fig3 is cross - sectional end view of the three - catheter , substantially coaxial section comprising third ( i . e ., innermost ) catheter 32 contained within second catheter 34 in a substantially coaxial and sliding arrangement . as used herein , a substantially coaxial arrangement is defined as at least one element contained within a second element wherein the elements do not necessarily share a common centerline , centroid or common axis . for example in fig3 the centroid of the innermost catheter 32 is offset from the centroid of the second catheter 34 . both catheter components 32 and 34 are similarly contained within first catheter 36 in a substantially coaxial and sliding arrangement forming a three catheter substantially coaxial section . the distal ends of the second and third catheters can extend distally beyond the first catheter distal end . moreover , the distal end of the third catheter can extend distally beyond the second catheter distal end . shown in fig4 is a cross - sectional end view of a transitional mid - section showing the third catheter 32 oriented in a side - by - side or collateral relationship to the second catheter 34 . the third and second catheters are in an “ internal ” relationship to and contained by the first catheter 36 . the transitional mid - section can move from one point to another within the first catheter by pushing or pulling the second and / or third catheters . fig5 is a cross - sectional end view of a proximal , dual coaxial section of the y - arm hub assembly . shown is the second catheter 34 in a substantially coaxial relation with first proximal end 38 of the y - arm hub assembly . also shown is the third catheter 32 in a substantially coaxial relation with second proximal end 40 of the y - arm hub assembly . fig6 is a partial longitudinal cross - section of a proximal dual coaxial section 26 shown here as a y - arm hub assembly . shown is a first proximal end 38 terminating with a first proximal opening . second catheter 34 extends , in a coaxial relationship , through the first proximal . opening . also shown is second proximal end 40 , terminating with a second proximal opening . third catheter 32 extends , in a coaxial relationship , through the second proximal opening . these catheter components form a dual coaxial section at the y - arm hub assembly . as shown , along the distal portion 42 of the y - arm hub assembly , the third catheter 32 is oriented in a collateral relationship to the second catheter 34 ( as also depicted in fig4 ). the third 32 and second 34 catheters extend distally from the y - arm hub assembly in a collateral relationship to a transitional mid - section 24 , as shown in partial longitudinal cross - section in fig7 ( scale enlarged relative to fig6 ). shown in fig7 is a third innermost catheter 32 protruding through a port or opening 44 in the wall of the second catheter 34 . the third catheter 32 therefore transitions from a collateral relationship to a substantially coaxial relationship relative to the second catheter 34 . both catheters 32 and 34 are similarly contained within first catheter 36 in a substantially coaxial arrangement , forming a three component substantially coaxial distal section . since the third innermost catheter 32 exits the wall of the second catheter 34 , the second catheter is ideally constrained from rotating relative to the remaining two catheters . to prevent the inadvertent rotation of the second catheter 34 , for example during the attachment of a connector onto the first proximal end 38 of the y - arm hub assembly , a floating connector is provided to the proximal end of the second catheter . the floating connector is free to rotate independently of the catheter shaft 34 . further details relating to the anti - rotation features of the floating connector are presented below . to illustrate the use of one delivery system according to the present invention , fig8 through 10 show various stages of a helex ™ septal occluder deployment sequence . shown in fig8 is a helex ™ septal occluder 28 loaded into delivery system 20 . such a system can typically be packaged for shipment in the configuration shown in fig1 ( that is with the helex ™ septal occluder in a deployed state and floating connectors connected to first and second proximal ends of the first catheter . particularly useful floating connectors can be of the “ luer ” type connector . the description will exemplify such luer type connectors . however , the skilled artisan will understand the various alternative embodiments that can be used . starting with the configuration shown in fig1 , the floating male luer 46 located on the proximal end of the second catheter 34 is unlocked from the first proximal end of the first catheter 36 by a counter - clockwise rotation . this counter - clockwise rotation is not translated to the second catheter 34 due to the design of the floating luer 46 . the helex ™ septal occluder 28 is pulled into the first catheter 36 of the delivery system 20 by pulling the floating luer 46 along with the second catheter 34 in a proximal direction 48 . when approximately 90 % of the helex ™ septal occluder 28 is pulled into the first catheter 36 , the second floating luer 52 located on the proximal end of the third catheter 32 is unlocked from the second proximal end of the first catheter 36 by a counter - clockwise rotation . this counter - clockwise rotation is not translated to the third inner catheter 32 due to the design of the floating luer 52 . it should be understood that a floating connector for the third catheter is an optional embodiment , as preventing twisting or rotation of the third catheter is not as critical as preventing twisting or rotation of the second catheter . however , use of the floating connector on the third catheter can still be desirable . the remaining 10 % of the helex ™ septal occluder is then pulled into the first catheter 36 by pulling the floating male luer 46 along with the second catheter 34 in a proximal direction 48 . the third inner catheter 32 is forced to move in the proximal direction 50 as the second catheter 34 is pulled in the proximal direction 48 . fig8 depicts a helex ™ septal occluder 28 fully loaded into the first catheter 36 and ready for use by the physician . the delivery system 20 with the fully loaded device is then advanced through the vasculature and positioned , for example , across a septal defect . the helex ™ septal occluder 28 can then be deployed by translating the third and second catheters relative to the first catheter , in a series of push - pull motions . shown in fig9 is a helex ™ septal occluder 28 in a partially deployed state . the floating luers 46 and 52 can be locked and unlocked during the delivery sequence without imparting a twisting motion to the third and second catheters . the push - pull delivery sequence is continued until the helex ™ septal occluder 28 is fully deployed as shown in fig1 with a portion of the device located on each side of the septal defect , thus occluding the defect . as will now be appreciated , the improved delivery system of the present invention allows the user to maintain a close hand - to - hand spacing throughout the delivery sequence . further , exemplary description of the floating connectors will now be presented . an aspect of the invention comprises a connector that is free to rotate relative to a catheter shaft without applying torsional force to the catheter shaft . the connector is therefore free to rotate independently of the catheter shaft . thus , inadvertent twisting of the catheter shaft can be avoided while connecting the connector to the proximal end of another catheter . exemplary configurations include floating luer - type connectors . examples of such floating luers are shown in schematic in fig1 a and 11b . shown in fig1 a is a general floating luer 54 having an internal containment groove 60 . also shown is a general catheter 56 that includes at least one protrusion , in this case ring 58 . protrusion or ring 58 can be an integral part of the catheter shaft , or it can be joined to the shaft using , for example , suitable adhesives . the ring 58 is contained in the luer internal containment groove 60 . thus , the ring 58 and containment groove 60 act as longitudinal constraint to allow the catheter 56 to be pushed and pulled while grasping floating luer 54 . the luer can be assembled onto the catheter 56 by inserting and joining first and second luer portions 62 , 64 together by an adhesive or any other suitable attachment means . the joined luer portions 62 , 64 are free to rotate relative to the catheter 56 . an alternate floating luer configuration is shown in fig1 b . shown is a general floating luer 66 longitudinally constrained by an external groove 68 formed by two opposing catheter stop components 70 , 72 . the two catheter components can be attached to the catheter shaft 56 , forming a groove 68 , or the catheter can be molded in this configuration . the luer 74 is free to rotate relative to the catheter shaft 56 . the catheter 56 can be longitudinally translated by pushing or pulling on the luer 74 . a further embodiment of a floating luer assembly is depicted in partial cross - section in fig1 . this configuration is similar in function to that shown in fig1 b and is similar to the luer numbered 52 in fig8 through 10 . shown in fig1 is a floating luer 52 with catheter 32 . the catheter 32 is retained within the luer 52 by a proximal stop 76 and a distal stop 78 . the proximal stop 76 and the distal stop 78 can be attached to the catheter 32 by an adhesive or any other suitable attachment means . the floating luer 52 is free to rotate relative to the catheter shaft 32 . the catheter can be longitudinally translated by pushing or pulling on the luer 52 . a still further embodiment of a floating luer assembly is depicted in partial cross - section in fig1 . this configuration is similar in function to that shown in fig1 b and is similar to the luer numbered 46 in fig8 through 10 . shown in fig1 is a floating luer 46 with catheter 34 . the catheter 34 is retained within the luer 46 by a proximal stop 80 and a distal stop 82 . the proximal stop 80 and the distal stop 82 can be attached to the catheter 34 by an adhesive or any other suitable attachment means . the luer 46 is free to rotate relative to the catheter shaft 34 . the catheter can be longitudinally translated by pushing or pulling on the luer 46 . the proximal stop 80 is a female luer fitting . this female luer allows the attachment of other components such as male luers , syringes , flushing instruments , etc . various materials that can be used to fabricate the individual components of the delivery system are well within the purview of the skilled artisan . while particular embodiments of the present invention have been illustrated and described above , the present invention should not be limited to such particular illustrations and descriptions . it should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims .
novel delivery systems suitable for delivering , for example , implantable devices . delivery system comprises a three - catheter system in conjunction with at least one floating connector . delivery system may be particularly suitable for delivering septal occlusion devices to a patient &# 39 ; s heart .