[21] Appl. No.: 752,387
[22] Filed: Nov. 20, 1996
Related U.S. Application Data
[63] Continuation of Ser. No. 532,053, Sep. 22,1995, abandoned.
[51] Int. CI. A61M 5/178
[52] U.S. CI 604/164; 604/170; 604/264;
606/185
[58] Field of Search 604/93, 104, 106-7,
604/164, 166, 263-4, 272, 170; 606/167,
185
[56] References Cited
U.S. PATENT DOCUMENTS
5,263,937 11/1993 Shipp 604/164
5,279,575 1/1994 Sugarbaker .
5,300,070 4/1994 Gentelia et al. .
5,350,393 9/1994 Yoon 606/185
5,372,588 12/1994 Farley et al 606/185
Primary Examiner—Michael Powell Buiz
Assistant Examiner—Ellen S. Tao
Attorney, Agent, or Firm—Larson & Taylor
[57] ABSTRACT
A trocar device, comprising a trocar cutting element, a surrounding insulating sheath, and a cannula surrounding the sheath, also includes an arrangement providing a substantially smooth transition between the sheath and cannula at the distal end of the cannula during the insertion of the trocar device into a patient so as to reduce drag on the device at the transition. In one embodiment, the sheath includes a shaped portion of enlarged diameter, and the cannula includes, at the distal end thereof, inwardly directed slits forming corresponding resilient leaf members which engage the shaped portion to provide the smooth transition. The shaped portion includes oppositely tapered surfaces meeting at a common apex. In another embodiment, an expandable section, when expanded, provides the smooth transition.
7 Claims, 5 Drawing Sheets
|
