1. A zoom lens comprising, in the following order from the object side to the image side:
a positive first lens unit;
a negative second lens unit, the second lens unit moving during zooming;
a positive third lens unit; and
a positive fourth lens unit, the fourth lens unit moving during zooming,
wherein the first lens unit includes a negative lens subunit and a positive lens subunit,
the negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens arranged in the mentioned order from the object side, and
the positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged in the mentioned order from the object side, or at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged in the mentioned order from the object side.
2. A zoom lens according to claim 1, wherein the absolute value of the refractive power of the object side surface of the positive lens disposed closest to the image side in the positive lens subunit is larger than the absolute value of the refractive power of the image side surface of the positive lens disposed closest to the image side in the positive lens subunit, and the object side surface of the positive lens disposed closest to the image side in the positive lens subunit is a convex surface.
3. A zoom lens according to claim 1, wherein in the case where the positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged in the mentioned order from the object side, said at least two positive lens comprises two positive lenses each having a convex surface facing the object side, and in the case where the positive lens subunit includes at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged in the mentioned order from the object side, the at least one positive lens comprises one or two positive lenses each having a convex surface facing the object side.
4. A zoom lens according to claim 1 further comprising a positive fifth lens unit disposed on the image side of the fourth lens unit.
5. A zoom lens according to claim 1 satisfying the following condition:
1.2<f3f5<3.6
where f3 is the focal length of the third lens unit, and f5 is the focal length of the fifth lens unit.
6. A zoom lens according to claim 1 satisfying the following condition:
1.8<|f1af1|<4.0
where f1a is the focal length of the negative lens subunit, and f1 is the focal length of the first lens unit.
7. A zoom lens according to claim 1 satisfying the following condition:
\u22127.7<H12wfw<\u22123.5
where H12w is the principal point interval of the first lens unit and the second lens unit at the wide angle end, and fw is the focal length of the entire lens system at the wide angle end.
8. A zoom lens according to claim 1 satisfying the following condition:
\u22120.09<f1R1bF<0.455
where R1bF is the radius of curvature of the object side surface of the negative lens in the positive lens subunit, and f1 is the focal length of the first lens unit.
9. A zoom lens according to claim 1 satisfying the following conditions:
2.8<|f2fw|<5.2
6.4<BF\xd7\u221a{square root over (FnoW)}fw<15.0
where f2 is the focal length of the second lens unit, fw is the focal length of the entire system at the wide angle end, FnoW is the F-number of the entire lens system at the wide angle end, and BF is the equivalent distance in air of the distance from the lens surface closest to the image side to an image plane at the wide angle end.
10. A zoom lens according to claim 1, wherein the third lens unit includes a plurality of lenses arranged with at least one air gap therebetween, and the zoom lens satisfies the following condition:
0.01<D3af3<0.1
where D3a is the length of said at least one air gap along the optical axis, and f3 is the focal length of the third lens unit.
11. A zoom lens according to claim 1 satisfying the following condition:
0.02<f1 f1FF<0.83
where f1FF is the focal length of the composite lens system composed of the negative lens subunit and the biconvex positive lens in the positive lens subunit, and f1 is the focal length of the first lens unit.
12. A zoom lens according to claim 1, wherein the zoom lens is adapted to form an image of an object on a solid state image pickup element.
13. An image pickup apparatus comprising:
a solid state image pickup element; and
a zoom lens according to claim 1 adapted to form an image on the solid state image pickup element.
14. A zoom lens comprising, in the following order from the object side to the image side:
a positive first lens unit;
a negative second lens unit, the second lens unit moving during zooming;
a positive third lens unit; and
a positive fourth lens unit, the fourth lens unit moving during zooming,
wherein the first lens unit includes a negative lens subunit and a positive lens subunit,
the negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens, and
said positive lens subunit includes at least three positive lenses and at least one negative lens, or at least two positive lenses and a cemented lens composed of a negative lens and a positive lens.
15. An image pickup apparatus comprising:
a solid state image pickup element; and
a zoom lens according to claim 14 adapted to form an image on the solid state image pickup element.
16. A zoom lens comprising, in the following order from the object side to the image side:
a positive first lens unit;
a negative second lens unit, the second lens unit moving during zooming;
a positive third lens unit; and
a positive fourth lens unit, the fourth lens unit moving during zooming,
wherein the first lens unit includes a negative lens subunit and a positive lens subunit,
the negative lens subunit includes two negative lenses each having a concave surface facing the image side and a biconvex positive lens, the absolute value of the refractive power of the image side surface of the biconvex positive lens being larger than the absolute value of the refractive power of the object side surface of the same positive lens, and
the positive lens subunit includes a biconvex positive lens, a negative lens or a cemented lens composed of a negative lens and a positive lens, and a positive lens having a convex surface facing the object side, the absolute value of the refractive power of the object side surface of the last mentioned positive lens being larger than the absolute value of the refractive power of the image side surface of the same positive lens.
17. An image pickup apparatus comprising:
a solid state image pickup element; and
a zoom lens according to claim 16 adapted to form an image on the solid state image pickup element.
18. A zoom lens comprising, in the following order from the object side to the image side:
a positive first lens unit;
a negative second lens unit, the second lens unit moving during zooming;
a positive third lens unit; and
a positive fourth lens unit, the fourth lens unit moving during zooming,
wherein the first lens unit includes a negative lens subunit and a positive lens subunit,
the negative lens subunit includes two negative lenses each having a concave surface facing the image side and a biconvex positive lens, the absolute value of the refractive power of the image side surface of the biconvex positive lens being larger than the absolute value of the refractive power of the object side surface of the same positive lens, and
the positive lens subunit includes a biconvex positive lens, a negative lens having a concave surface facing the image side or a cemented lens composed of a negative lens having a concave surface facing the image side and a positive lens, and two positive lenses each having a convex surface facing the object side.
19. An image pickup apparatus comprising:
a solid state image pickup element; and
a zoom lens according to claim 18 adapted to form an image on the solid state image pickup element.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A suture securement apparatus for selectively and releasably securing the ends of a suture utilized in a purse string suture utilized to maintain hemostasis and close a percutaneous catheter puncture site, the suture securement apparatus comprising:
a body having a cavity positioned therein;
a plunger slidably disposed within the cavity of the body;
a biasing spring positioned within the cavity of the body and engaging the plunger to bias the plunger and allow for releasable engagement of the sutures;
an extension tube extending a predetermined distance from the body such that a tip of the extension tube is adaptable to engage the sutures adjacent the suture insertion point without interruption from the body.
2. The suture securement apparatus of claim 1, wherein the plunger comprises a release button.
3. The suture securement apparatus of claim 1, wherein the extension tube comprises an extension tube lumen.
4. The suture securement apparatus of claim 3, wherein the plunger includes a plunger lumen.
5. The suture securement apparatus of claim 4, wherein sutures secured by the suture securement apparatus can be moved relative to the suture securement apparatus when the extension tube lumen and the plunger lumen are aligned.
6. The suture securement apparatus of claim 4, wherein sutures secured by the suture securement apparatus are secured relative to the suture securement apparatus when the extension tube lumen and the plunger lumen are not aligned.
7. The suture securement apparatus of claim 1, wherein the extension tube is integrally coupled to the body of the suture securement apparatus.
8. The suture securement apparatus of claim 1, wherein the tip of the extension tube has a smaller outside diameter than the outside diameter of the portion of the extension tube positioned adjacent the body.
9. The suture securement apparatus of claim 1, further comprising a threading assembly having a base and a suture engaging portion for facilitating threading of the suture through a lumen of the suture securement apparatus.
10. A method of utilizing a suture securement apparatus for selectively and releasably securing the ends of a suture utilized in a purse string suture utilized to maintain hemostasis and close a percutaneous catheter puncture site, the method of securing a purse string suture comprising:
providing suture securement apparatus having an extension tube;
providing a threading assembly having a base and a suture engaging portion for facilitating threading of the suture through a lumen of the suture securement apparatus;
threading a first tail and a second tail of a purse string suture through the extension tube utilizing the threading assembly of the suture securement apparatus;
exerting a desired degree of tension on the first tail and the second tail such that the smaller diameter of the extension tube draws the first tail and second tail closer to one another than the distance between the insertion point and the second point; and
maintaining a desired degree of tension on the first tail and second tail of the suture utilizing the suture securement apparatus.
11. The method of claim 10, wherein the suture engaging portion of the threading assembly comprises a suture loop.
12. The method of claim 10, wherein the base of the threading assembly comprises a clasp.
13. The method of claim 12, wherein the clasp secures the suture engaging portion.
14. The method of claim 10, wherein at least a portion of the threading assembly is positioned through a lumen of the suture securement apparatus before threading the first tail and the second tail through the extension tube.
15. The method of claim 10, wherein the user retracts at least a portion of the threading assembly from the lumen of the suture securement apparatus to thread the first tail and second tail through the extension tube.
16. The method of claim 10, wherein the suture securement apparatus comprises a release button.
17. The method of claim 10, wherein when the release button is released, the first tail and second tail are secured in the suture securement apparatus.
18. The method of claim 17, wherein when the release button is depressed, the first and second tail can be repositioned within the suture securement apparatus.
19. A method of utilizing a suture securement apparatus for selectively and releasably securing the ends of a suture utilized in a purse string suture utilized to maintain hemostasis and close a percutaneous catheter puncture site, the method of securing a purse string suture comprising:
providing suture securement apparatus comprising a body having a cavity positioned therein, a plunger slidably disposed within the cavity of the body, and a biasing spring positioned within the cavity of the body and engaging the plunger to bias the plunger;
threading a first tail and a second tail of a suture through an extension tube of the suture securement apparatus;
exerting a desired degree of tension on the first tail and the second tail such that the smaller diameter of the extension tube draws the first tail and second tail closer to one another than the distance between the insertion point and the second point; and
maintaining a desired degree of tension on the first tail and second tail of the suture utilizing the suture securement apparatus.
20. The method of claim 19, wherein the diameter of at least a portion of a lumen of the extension tube is smaller than the distance between the insertion point of the first tail into the patient and the emergence point of the second tail from the patient.