Syringe for balloon catheterization

Claim 2

A balloon catheter syringe having a syringe body comprising: a barrel with an inner bore of substantially uniform diameter supported by said syringe body; a resilient plunger end cap member sized to make sealing contact with said inner bore of said barrel, said plunger having a continuous face for contacting a fluid within said barrel and a backside structured to engage the distal end of a piston; an outer piston reciprocally moveable within said inner bore of said barrel, said outer piston joined to said end cap, said outer piston being joined at one end to a proximal handle and having an internal bore structured to receive a second, smaller piston; a second piston slidingly engaging said internal bore of said outer piston, said second piston having a distal end structured to engage the backside of said resilient plunger end cap member and capable of causing said end cap member face to flex when said inner piston is moved against or removed from contacting the backside of said end cap member; and means for restraining length of travel of said inner piston within said outer piston.

Claim 3

The balloon catheter syringe of claim 1, wherein said restraining means comprises a predetermined proximal length of second piston extending from the rear of the handle of the outer piston when said second piston has its distal end in substantial contact with the backside of said end cap.

Claim 4

The balloon catheter syringe of claim 1, wherein said restraining means comprises a lateral projection on said second piston which engages a slot opening having a straight portion of a predetermined length in the wall of said outer piston, said lateral projection being restrained in the distance it can reciprocate lengthwise by said slot.

Claim 5

The balloon catheter syringe of claim 1, wherein said restraining means is structured to position said second piston in its rest position so that it is in a forward position such that its distal end is in substantial contact with the backside of said resilient end cap.

Claim 6

The balloon catheter syringe of claim 3, wherein said slot is a "J" shaped slot having the curved portion of the "J" in a forward location.

Claim 7

The balloon catheter syringe of claim 5, wherein the lateral projection resides at the end of the curved portion of the "J" shaped slot when the second piston is in a rest position.

Claim 8

The balloon catheter syringe of claim 1, wherein said means for restraining length of travel of said inner piston is a spring member interacting with said second piston which causes the distal end of said second piston to contact the backside of said end cap and which resists pressure on the face of said end cap to prevent any substantial rearward movement of said second piston.

Claim 9

The balloon catheter syringe of claim 7 wherein said second piston is structured to have retraction means whereby a force can be externally applied to said second piston to retract said piston to allow the resilient end cap face to collapse from pressure existing in the barrel of the syringe.

Claim 10

The balloon catheter of claim 8 wherein said retraction means is a handle positioned near the proximal end of said piston, said handle being positioned forward of said outer piston handle whereby said second piston handle may be moved rearward by squeezing both handles with one hand.

Claim 11

A balloon catheter syringe having a syringe body and a barrel having a plunger tightly fitting within said barrel, a threaded plunger rod fitted to said plunger and a moveable thread engaging member interacting with said threaded plunger; the improvement comprising: a cylindrical cam member rotatably attached to said syringe body rotatable about its longitudinal axis having means to interact with said thread engaging member to engage and disengage said thread engaging member from the threads of said threaded plunger rod upon rotation of said cam member in opposite directions whereby said thread engaging member moves towards or away from said threaded plunger rod upon rotation of said cam member in different directions, a compression spring member structured to interact with said thread engaging member to maintain said thread engaging member in an engaged position.

Claim 12

A balloon catheter syringe having a syringe body and a barrel having a plunger tightly fitting within said barrel, a threaded plunger rod fitted to said plunger and a moveable thread engaging member interacting with said threaded plunger; the improvement comprising: a cylindrical cam member rotatably attached to said syringe body rotatable about its longitudinal axis having means to interact with said thread engaging member to engage and disengage said thread engaging member from the threads of said threaded plunger rod upon rotation of said cam member in opposite directions whereby said thread engaging member moves towards or away from said threaded plunger rod upon rotation of said cam member in different directions, a compression spring member structured to interact with said thread engaging member to maintain said thread engaging member in an engaged position.

Claim 13

A balloon catheter syringe having a barrel, a displaceable piston and a threaded piston rod attached at its distal end to said displaceable piston, said syringe comprising: a syringe body for supporting said barrel; a smooth bore contained within said body, said bore size to receive said piston; a splined block contained within said syringe body, said block displaceable transversely to said piston rod to occupy two positions, a first position being a piston rod thread engaging position and a second disengaging position; a splined block actuator mechanism having a threaded screw member rotatably attached to said body with the threaded position of said screw engaging said splined block whereupon rotation of said screw around its central longitudinal axis in one direction causes said splined block to engage said piston rod and rotation of said screw in an opposite direction disengages said splined block from the threads of said piston rod; and a spiral compression spring structured to encircle said screw member and supported at one end by the syringe body and at the other end said spring contacting said splined block to maintain said block in an engaged position.

Claim 14

A balloon catheter syringe having a barrel, a displaceable piston and a threaded piston rod attached at its distal end to said displaceable piston, said syringe comprising: a syringe body for supporting said barrel; a smooth bore contained within said body, said bore size to receive said piston; a splined block contained within said syringe body, said block displaceable transversely to said piston rod to occupy two positions, a first position being a piston rod thread engaging position and a second disengaging position; a splined block actuator mechanism having a threaded screw member rotatably attached to said body with the threaded position of said screw engaging said splined block whereupon rotation of said screw around its central longitudinal axis in one direction causes said splined block to engage said piston rod and rotation of said screw in an opposite direction disengages said splined block from the threads of said piston rod; and a spiral compression spring structured to encircle said screw member and supported at one end by the syringe body and at the other end said spring contacting said splined block to maintain said block in an engaged position.

Claim 15

The balloon catheter syringe of claim 11 wherein said spiral spring is structured to complete substantially only one revolution around said screw member.