US 5,152,754 A · Trocar

Abstract

A trocar for placement in the lumen of a cannula to facilitate inserting the cannula through the wall of a body cavity, the trocar comprising an obturator with a point for piercing the wall of the body cavity, and a protective sleeve mounted concentrically around the obturator. The obturator retracts proximally relative to the protective sleeve after the trocar point has penetrated through the wall of the body cavity. The protective sleeve is mounted for axial movement relative to the obturator, retracting proximally in response to drag from the wall of the body cavity as the trocar is advanced through the wall, and advancing distally after the cannula has penetrated through the wall, reducing the drag on the sleeve. The distal advancement of the sleeve triggers the retraction of the obturator.

Claims17

Dependent claims

A trocar for placement in the lumen of a cannula to facilitate inserting the cannula through the wall of a body cavity, the trocar comprising a handle, an obturator with a point for piercing the wall of the body cavity, and a protective sleeve mounted concentrically around the obturator, the obturator retracting proximally relative to the handle generally simultaneously as the protective sleeve advances distally relative to the handle after the trocar point has penetrated through the wall of the body cavity.

A trocar for placement in the lumen of a cannula to facilitate inserting the cannula through the wall of a body cavity, the trocar comprising:

a handle;
an obturator extending distally from the handle and having a point on its distal end for piercing the wall of the body cavity;
a protective sleeve mounted concentrically around the obturator for axial movement relative to the obturator, and resiliently biased distally so that the protective sleeve can retract proximally relative to the obturator in response to drag from the wall of the body cavity as the trocar point is advancing through the wall of the body cavity, and can advance distally after the cannula has penetrated through the wall of the body cavity and reduced the drag on the protective sleeve;
and
means for retracting the obturator relative to the handle generally at the same time the protective sleeve advances distally relative to the handle after the trocar point has penetrated through the wall of the body cavity.

2 more elements

A trocar for placement in the lumen of a cannula to facilitate inserting the cannula through the wall of a body cavity, the trocar comprising:

a handle;
an obturator extending distally from the handle and having a point on its distal end for piercing the wall of the body cavity;
a protective sleeve mounted concentrically around the obturator for axial movement relative to the obturator, and resiliently biased distally so that the protective sleeve can retract proximally relative to the obturator in response to drag from the wall of the body cavity as the trocar point is advancing through the wall of the body cavity, and can advance distally after the cannula has penetrated through the wall of the body cavity and reduced the drag on the protective sleeve;
biasing means for biasing the obturator proximally relative to the protective sleeve;
means for releasably securing the obturator from proximal retraction under the bias of the biasing means;
and
means for releasing the releasable securing means upon the proximal retraction of the protective sleeve that occurs while the trocar is advancing through the wall of the body cavity, and the subsequent distal advancement of the protective sleeve that occurs after the cannula has penetrated through the wall of the body cavity.

4 more elements

Dependencies are inferred from the claim text.

Trocar

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Trocar

Life of this patent

Abstract

Claims17