Surgery – Specula – Retractor
Reexamination Certificate
1999-05-21
2001-03-06
Smith, Jeffrey A. (Department: 3732)
Surgery
Specula
Retractor
C600S219000
Reexamination Certificate
active
06196969
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to surgical instruments and more specifically to tissue retractors for use in various surgical procedures.
2. Description of Related Art
Surgical retractors are well known in the medical arts, particularly retractors that separate body tissue to enable a surgeon access to an operating site. Generally these retractors include two arms that can pivot about an axis at an intermediate position to form a scissors-like mechanism. Squeezing finger grips at one end of each arm causes a pair of retractor claws at the other ends of each arm to separate. Once the desired tissue separation is achieved, a ratchet sector on one arm and a pawl on the other arm lock the arms in place relative to each other and thereby maintain the tissue separation. The following patents disclose some examples of such retractors:
U.S. Pat. No. 3,038,467 (1962) Sovatkin
U.S. Pat. No. 3,470,872 (1969) Grieshaber
These retractors, however, only provide separation at two opposed locations. The following patent:
U.S. Pat. No. 3,998,217 (1976) Trumbull et al. discloses another type of retractor device that engages tissue at four different positions. While such an approach provides more tissue contacts, it has not gained wide acceptance. Scissors-type retractors continue to be the instruments of choice.
There has also been introduced a variation on a scissors-type retractor whereby a central claw attaches to the retractor to provide three tissue contacts. Specifically, one retractor with this capability includes two retractor arms that can pivot about a pivot axis. Each arm includes a finger grip and a claw at opposite ends. A central claw has an intermediate planar portion with a clearance passage at an intermediate location along an elongated slot. A wing bolt attaches to a threaded receptacle formed in one of the arms along the pivot axis. To attach the central claw, a surgeon grasps the retractor in one hand and uses the other hand to loosen the wing bolt. Then the surgeon aligns the clearance passage with the wing bolt so that the central claw passes over the wing bolt. The surgeon must then displace the central claw so that a flange on the wing bolt overlies portions of the central claw to capture it. Next the surgeon positions the central claw against a patient's tissue and then tightens the wing bolt to effect clamping solely by generating frictional forces between smooth facing surfaces of the wing bolt flange and the central claw.
This arrangement does advantageously increase the number of tissue contact points. However, if it becomes necessary to reset the position of the central claw, the surgeon must use both hands to hold the retractor in position, loosen the wing bolt, move the central claw and then hold the central claw in position while tightening the wing bolt. In addition, the clearance passage through the central claw limits the range of longitudinal motion of the central claw. As will be apparent, it will not be possible to move the central claw to a position at which the clearance passage aligns with the wing bolt. If such an alignment occurs, the central claw will detach from the retractor. Moreover, the central claw clamps to one of the arms thereby fixing the angular position of the central claw relative to that arm. If the surgeon adjusts the arm separation, the central claw will move with that arm in a fixed angular relationship. Consequently, the central arm will not be equiangularly spaced from the two arms without repositioning the central claw as described above. What is needed is a scissors-type retractor that a surgeon can operate with one hand even when attaching or manipulating a central claw and that maintains equiangular spacing between the central claw and the retractor arms even as the surgeon changes the separation of the retractor arms.
SUMMARY
Therefore, it is an object of this invention to provide a tissue retractor with the ability to attach a central claw in a simple one-handed operation.
Another object of this invention is to provide a tissue retractor with a central claw that is readily adjustable position-wise in a simple one-handed operation.
Still another object of this invention is to provide a tissue retractor in which a central claw remains centered during adjustment of the retractor arms.
In accordance with one aspect of this invention, a tissue retractor includes first and second arms connected to rotate about a pivot axis. Each arm includes a retractor claw at one end. A clamp on the pivot axis mounts to the first and second arms for adjustment between first and second positions. The clamp, in its first position, enables the auxiliary element to be positioned relative to said pivot. In a second position, the clamp produces positive interference to relative motion between the clamp and the auxiliary element.
In accordance with another aspect of this invention a tissue retractor comprises first and second arms connected to rotate about a pivot axis, each arm including a retractor claw at one end thereof for engaging tissue. An auxiliary claw has an elongated intermediate body portion with an elongated slot therethrough. A central actuator extends through the first and second arms along the pivot axis, and an elongated clamping member attaches to an end of the central actuator. The central actuator and clamping member are movable axially and angularly relative to the first and second arms between a mounting end position and a clamping end position. The clamping member is aligned with the elongated slot in the auxiliary claw in the mounting end position and is transverse to the elongated slot in the clamping end position.
In accordance with still another aspect of this invention, a tissue retractor comprises first and second retractor arms each having a grip at a first end and interfitting intermediate portions that define a pivot axis. A hinged, replaceable claw mechanism is located at the second end of each arm. A flanged sleeve mounts through the interfitting intermediate portions in a first direction along the pivot axis whereby the first and second retractor arms can rotate about the sleeve. A centering body has a portion extending into the sleeve in the first direction and can be rotated with respect to the sleeve and first and second retractor arms. The centering body also has elongated planar support surfaces formed parallel to the flange on the sleeve on opposite sides of the pivot axis. Centering springs between the centering body and each of the first and second retractor arms center the centering body angularly with the elongated planar support surface lying along an axis intermediate axes through each of the retractor arms. A spring biased actuator with a transverse portion and a body portion extends through the sleeve and centering body portion in a second direction along the pivot axis. An elongated clamp attaches to the actuator body portion from the other direction so the transverse portion and the clamp are positioned on opposite sides of the interfitting, intermediate portions of the retractor arms with the actuator and clamp being angularly and axially displaceable between a mounting end position when the clamp is positioned on the support surfaces and a clamping end position when the clamp is rotated to be transverse to the support surfaces. With this structure a center claw having an intermediate portion with an elongated slot and a toothed surface, a claw and a handle portion extending from the opposite ends of the intermediate portion can be easily attached when the clamp is in the mounting end position. In an intermediate position of the clamp the center claw can move in either direction with respect while remaining captured to the retractor. In the clamping end position the clamp and toothed portions of the center claw provide a one-way ratchet to limit motion of the central claw toward the handle portions of the first and second arms.
REFERENCES:
patent: D. 378780 (1997-04-01), Shuler
patent: 569839 (1896-10-01), Roeloffs
patent: 579625 (1897-03
Bester Leon W.
Walsh David A.
Herbster George A.
Lab Engineering & Manufacturing, Inc.
Pearson & Pearson
Smith Jeffrey A.
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