an overall view of a preferred embodiment of the invention is shown in fig1 including the knot pusher assembly 20 and the plunger assembly 80 . as shown in fig1 and also in more detail in the side sectional views of fig2 the knot pusher assembly 20 includes a pusher tube 22 and an inner concentric tube 50 . at the proximal end of the knot pusher assembly 20 , the pusher tube is attached to a cylindrical handle 24 and the inner concentric tube 50 is attached to a rotator 52 having a longitudinal , radially extending wing 54 . the proximal end of the inner concentric tube 50 extends beyond the proximal end of the pusher tube 22 to allow the connection between the inner concentric tube 50 and the rotator 52 . the rotator 52 includes a sleeve 56 which extends from the region where the rotator 52 is connected to the inner concentric tube 50 , distally over the proximal end of the pusher tube handle 24 . an annular space is provided between the rotator sleeve 50 and the inner connector tube 50 , which receives a coil spring 60 , one end of which is attached to the inner concentric tube 50 or rotator 52 , and the other end of which is attached to the pusher tube 22 or pusher tube handle 24 . the rotator 52 is capped at the proximal end by a cap 62 . the pusher tube 22 and inner concentric tube 50 are rotatable with respect to one another . this rotation is accomplished by rotating the rotator 52 in relation to the handle 24 . the rotation biases and is therefore resisted by the coil spring 60 . the distal end of the knot pusher assembly 20 includes the distal ends of the pusher tube 22 and inner connector tube 50 , which are better shown in the detail view of fig3 - 6 . fig3 and fig4 are detailed views showing the distal end of the pusher tube 22 and inner concentric tube 50 . as can be seen , the distal end of the inner concentric tube 50 is slightly recessed from the distal end of the pusher tube 22 . moreover , the ends are specially shaped . the end of the pusher tube 20 has a bevel 30 on one side and has a indentation 32 on the opposite side . at the proximal extreme of the indentation 32 is a pusher tube slot 34 extending longitudinally toward the proximal end of the knot pusher assembly 20 . the end of the inner concentric tube 50 includes a bevelled side 66 and a flat portion 68 . intermediate in the flat portion 68 is an inner concentric tube slot 70 which extends longitudinally toward the proximal end of the knot pusher assembly 20 . the inner concentric tube slot 70 aligns with the pusher tube slot 34 when the inner concentric tube 50 is in its unrotated position in relation to the pusher tube 22 , or in other words , when the spring 60 in the proximal end of the knot pusher assembly 20 ( see fig2 ) is unbiased . as shown in the end view of fig6 when the inner concentric tube 50 is rotated in relation to the pusher tube 22 to bias the spring 60 , the inner concentric tube slot 70 becomes unaligned with the pusher tube slot 34 . in the aligned position of fig5 the aligned slots 34 and 70 can receive a length of material 72 . by rotating the inner concentric tube 50 in relation to the pusher tube 22 , they become unaligned to thereby cut the material 72 as shown in fig6 . the plunger assembly 80 is shown in detail in fig7 - 8 . the plunger assembly 80 includes a plunger shaft 82 which is a elongated tubular element . the proximal end of the plunger shaft 82 is attached to a plunger handle 84 . inside and concentric with the tubular plunger shaft 82 is a carrier releaser 86 which is also a tubular element . the distal end of the carrier releaser 86 coincides with the distal end of the plunger shaft 82 . the proximal end of the carrier releaser 86 extends past the proximal end of the plunger shaft 82 and into the interior cavity of plunger handle 84 where it engages the mechanism of a carrier release button 88 . the mechanism is any suitable arrangement which drives the carrier releaser 86 distally upon actuation of the carrier release button 88 . in the embodiment shown , the proximal end of the carrier releaser 86 is attached to a ramp 90 which engages a sloped surface on the carrier release button 88 . thus by pushing the carrier release button 88 into the plunger handle 84 , the sloped surface of the carrier release button 88 engages the ramp 90 at the proximal end of the carrier releaser 86 to drive the carrier releaser distally relative to the plunger shaft 82 and plunger handle 84 . this distal displacement has the effect of protruding the distal end of the carrier releaser 86 past the distal end of the plunger shaft 82 . the carrier releaser 86 may be biased toward the proximal end by a suitable spring ( not shown ) so that it returns proximally each time the carrier release button 88 is released . inside and concentric with the carrier release is a carrier holder 140 which is fixed in relation to the plunger shaft 82 . inside and concentric with the carrier holder 140 is a clamp holder 96 which extends from the distal end to the proximal end where it is attached to a clamp actuator 98 . the clamp actuator 98 is a cylindrical element received by the plunger assembly handle 84 . the clamp actuator 98 has a central cavity to contain the inner potion of the carrier release button 88 and the ramp 90 at the proximal end of the carrier releaser 86 . the distal end of the clamp actuator 98 abuts against the end of a coil spring 102 contained within the plunger assembly handle 84 so that the clamp actuator 98 and attached clamp holder 96 are biased proximally . the distal end of the clamp holder 96 is attached to a spring clamp 110 , better shown in fig8 - 9 , in which the carrier is omitted for clarity . fig8 shows the spring clamp 110 in the closed position , wherein the clamp holder 96 is positioned distally by the relaxed clamp actuator 98 so that the clamp holder 96 is retracted partially into the plunger assembly 80 . the proximal retraction of the clamp holder 96 urges the sloped backs 116 of the clamp jaws 118 against the distal end of the carrier holder 86 . the distal end of the carrier holder 140 thereby exert an axial force on the backs 116 of the clamp jaws 118 , to urge the clamp jaws 118 shut . in fig9 the clamp actuator 98 ( see fig7 ) has been depressed , to displace the clamp holder 96 and attached clamp jaws 118 distally . this causes the backs 116 of the clamp jaws 118 to protrude past the distal end of the carrier holder 140 , thereby allowing the clamp jaws 118 to assume their normally open position . the carrier 120 is shown in detail in fig1 . the carrier 120 includes a spool 122 and a sheath 124 over the spool 122 . the spool is a tubular element being flared at the distal end 125 with a plurality of longitudinally extending slots 126 . the slots 126 allow for space for the flared distal end to deform radially inward to reduce the effective diameter and circumference of the distal end 125 . at the proximal end of the spool 122 is a set of threads 130 on the radially outer surface . between the distal end 125 and proximal end is a radially extending ring 132 . a length of material and a knot , together 142 , is rolled onto the spool 122 in the region between the extreme digital end 125 and the ring 132 . the sheath 124 is also a tubular element , concentric with the spool 122 . at the distal end of the sheath , the radially inner surface is chamfered in the region overlying the flared distal end 125 of the spool . at the proximal end , the radially inner surface includes a set of threads 136 that mate with the threads 130 in the radially outer surface of the spool 122 . the spool 122 and the sheath 124 are held together by the engagement of these respective threads 130 and 136 . a detail of the carrier 120 positioned on the plunger assembly 80 is shown in fig1 . as can be seen , the carrier 120 slides over the distal end of the carrier holder 140 . the extreme distal end of the carrier holder 140 is dimensioned such that it exerts a radially outward force on the flared distal end 125 of the spool 122 of the carrier holder 120 . this radially outward force deforms the flared distal end 125 of the spool 122 radially outward to bind the material and knot 142 that is rolled onto the spool 122 , between the spool 122 and the sheath 124 . fig1 shows the carrier 120 being released from the carrier holder 140 . as explained above , the carrier 120 can be pushed partly off the carrier holder 84 by actuating the carrier release button 88 ( see fig7 ) to protrude the carrier releaser 86 distal end past the plunger shaft 82 distal end . this causes the flared distal end 125 of the carrier 120 to extend past the distal end of the carrier holder 140 , thereby allowing the flared distal end 125 of the carrier 120 to relax and contract radially . this relieves the binding force between the spool 122 and the sheath 124 so that the material 142 can come out of the carrier 120 . the operation of the device is shown in fig1 a - 12f . as shown in fig1 a , the knot pusher assembly 20 is inserted into a cannula 21 prior to the plunger assembly 80 being inserted into the knot pusher . this ensures the safety and security of the needle and suture during their insertion . the carrier 120 is then placed over the clamp 110 and onto the carrier 140 . a needle 150 is previously attached to the suture material 142 . the carrier 120 is then secured in the clamp 110 , and the plunger assembly 80 is inserted into the knot pusher assembly 20 . as shown in fig1 b , the needle 150 is taken from the clamp 110 by another instrument 160 ( such as a needle holder or clamp ) passing through another cannula . the needle 150 is passed through or around a feature , such as through tissue or around a vessel 170 , and handed back to the clamp 110 . as shown by fig1 c , the knot and material 142 is released from the carrier 120 by actuating the carrier release 86 to protrude the carrier 120 past the distal end of the carrier holder 140 so that the flared distal end 125 of the carrier spool 122 relaxes radially inward to relieve the binding on the knot and material 142 ( see fig1 ). this releasing of the knot and material provides the necessary slack in the material to accomplish the suturing or tying . the releasing of the knot allows the knot to lightly cinch down on the lead end of the material which is now grasped by the clamp 110 . as shown in fig1 d , pulling on the plunger assembly within the knot pusher assembly 20 while pushing on the knot pusher assembly 20 retracts and tensions the leads of the material 140 which allows the knot pusher assembly 20 to engage the leads . specifically , the leads pass into the aligned pusher tube slot 34 and inner concentric tube slot 70 ( see fig4 ). continued pulling on the plunger assembly 80 while pushing on the knot pusher assembly 20 tightens and drives the knot 142 into position against the vessel 170 to tightly tie the vessel 170 . the leads of material 140 may then be cut , either immediately adjacent to the knot or away from the knot to leave longer loose ends as desired . the cutting is accomplished by positioning the knot pusher assembly 20 at the cutting site , still with the material in the aligned pusher tube slot 34 and inner concentric tube slot 70 ( see fig4 again ). the inner concentric tube 50 is then rotated in relation to the pusher tube 22 ( see fig6 ) by rotating the rotator 52 while grasping the handle 24 ( see fig2 ) to unalign the pusher tube slot 34 and the inner concentric tube slot 70 . this leaves a tied knot on a vessel 170 as shown in fig1 f . the plunger assembly 80 is then withdrawn from the knot pusher assembly 20 , and the carrier 120 and material leads including the needle are discarded . the instrument is then ready to be reloaded with a new carrier 120 and needle for tying the next knot or suture .
a method and apparatus for placing and tying a knot such as laparoscopy knot . a knot pusher assembly including an outer tube and an inner tube are positioned , and a plunger assembly is plunger through the knot pusher assembly . the plunger assembly includes a knot carrier having an at least partially formed knot with a free end . the free end is placed around the object to be tied and grasped with a clamp . the knot is released from the knot carrier and the free end is pulled back through the partial knot to complete and tighten the knot . the knot is tightened and placed using the knot pusher assembly , and the free end is cut by placing it into aligned slots on the outer tube and inner tube , and rotating the inner tube in relation to the outer tube to unalign the slots .