Safety trocar
First Claim
Patent Images
1. A trocar comprising:
- (a) a cannula assembly comprising a cannula and a cannula housing defining an internal cannula passage, said cannula being reciprocally mounted with respect to said cannula housing for movement between a distal position and a proximal position;
(b) a trocar assembly adapted to cooperate with said cannula assembly, said trocar assembly comprising a piercing tip mounted to an obturator shaft and a trocar housing, said piercing tip and at least a portion of said obturator shaft being configured and dimensioned for entry into said internal cannula passage;
(c) releasable obturator means associated with the obturator shaft which releasably maintains the piercing tip in an extended position relative to said cannula;
(d) release means associated at least in part with the cannula assembly and actuated by movement of said cannula with respect to said cannula housing for releasing the releasable obturator means; and
(e) biasing means for retracting said piercing tip and said obturator shaft from said extended position to a retracted position in response to release of the releasable obturator means.
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Accused Products
Abstract
A safety trocar is provided in which the cannula is reciprocally mounted to the cannula housing and reciprocates into the cannula housing when a proximally directed force is applied thereto. The piercing tip is maintained in the exposed position by a latching mechanism associated with the obturator shaft, and is automatically withdrawn into the cannula under the force of a spring when the proximal force is removed from the cannula, the cannula thus advancing distally and releasing the latching mechanism. Penetration force is maintained at a minimum, and safe and efficacious trocar entry is facilitated.
241 Citations
28 Claims
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1. A trocar comprising:
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(a) a cannula assembly comprising a cannula and a cannula housing defining an internal cannula passage, said cannula being reciprocally mounted with respect to said cannula housing for movement between a distal position and a proximal position; (b) a trocar assembly adapted to cooperate with said cannula assembly, said trocar assembly comprising a piercing tip mounted to an obturator shaft and a trocar housing, said piercing tip and at least a portion of said obturator shaft being configured and dimensioned for entry into said internal cannula passage; (c) releasable obturator means associated with the obturator shaft which releasably maintains the piercing tip in an extended position relative to said cannula; (d) release means associated at least in part with the cannula assembly and actuated by movement of said cannula with respect to said cannula housing for releasing the releasable obturator means; and (e) biasing means for retracting said piercing tip and said obturator shaft from said extended position to a retracted position in response to release of the releasable obturator means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 22)
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18. A trocar comprising:
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(a) a cannula assembly comprising a cannula reciprocally mounted to a cannula housing, said cannula defining an internal shelf; (b) a trocar assembly comprising a piercing tip, an obturator shaft and a trocar housing; (c) latch means associated with said obturator shaft, said latch means adapted to releasably engage said internal shelf; and (d) biasing means for retracting said piercing tip from an extended position wherein said piercing tip extends beyond said cannula to a retracted position wherein said piercing tip is shielded by said cannula; wherein reciprocation of said cannula with respect to said trocar assembly releases said latch means from engagement with said internal shelf and allows said biasing means to retract said piercing tip to said retracted position. - View Dependent Claims (19, 20, 21)
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23. A method for inserting a trocar, comprising:
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(a) advancing an obturator shaft and a piercing tip to expose said piercing tip from a cannula, said piercing tip being maintained in said exposed position through engagement of latch means associated with said obturator shaft with a shelf formed in said cannula; (b) pressing said piercing tip against a body wall, said body wall thereby exerting a counterforce against said cannula and causing reciprocation of said cannula into a cannula housing against the bias of cannula biasing means; (c) entering said piercing tip into a body cavity, thereby removing said counterforce from said cannula, said cannula biasing means causing said cannula to move distally, thereby releasing said latch means from engagement with said shelf, whereby said piercing tip is automatically withdrawn into said cannula under the action of obturator biasing means. - View Dependent Claims (24, 25)
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26. A trocar comprising:
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(a) a cannula assembly comprising a cannula and a cannula housing defining an internal cannula passage; (b) a trocar assembly adapted to cooperate with said cannula assembly, said trocar assembly comprising a trocar housing and obturator means which includes a piercing tip at a distal end thereof, at least a portion of said obturator means being configured and dimensioned for entry into said internal cannula passage; (c) button means mounted to said obturator means and extending from said trocar housing for advancing said piercing tip to an extended position relative to said cannula; (d) latching means mounted to said trocar assembly and adapted to cooperate with engagement means, said latching means adapted to assume a latched position wherein said latching means engages said engagement means and maintains said piercing tip in said extended position relative to said cannula, and an unlatched position wherein said latching means is released from engagement with said engagement means; and (e) biasing means for retracting said piercing tip from said extended position to a retracted position after said latching means has assumed said unlatched position. - View Dependent Claims (27, 28)
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Specification