Safety trocar

• US 5,215,526 A
• Filed: 05/15/1991
• Issued: 06/01/1993
• Est. Priority Date: 07/06/1988
• Status: Expired due to Term

• Current Assignee: Ethicon Incorporated (Johnson & Johnson)
• Original Assignee: Ethicon Incorporated (Johnson & Johnson)
• Inventors: Failla, Stephen J., Deniega, Jose C.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): STRIGHT, RONALD K
• Application Number:
  US07/700,787
• Time in Patent Office: 748 Days
• Field of Search: 604/51, 604/117, 604/136, 604/157, 604/164-167, 604/170, 604/171, 604/264, 604/268, 604/272-274, 606/167, 606/170, 606/172, 606/185, 128/754
• US Class Current: 604/164.09
• CPC Class Codes: A61B 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612
• CPC Class Codes: A61B 2090/08021 of the patient or his organs

Abstract

A safety trocar is provided which includes a spring-loaded shield that shields the cutting tip of the obturator after the obturator penetrates tissue. The distal end of the shield is hemispheric in profile and contains a slot which conforms to the geometry of the cutting tip. The rounded distal end enables the shield to spring forward to shield the cutting tip as soon as the tip perforates the tissue. A valve is located at the proximal end of the trocar tube to seal the end of the tube. The valve is oriented at an acute angle with respect to the longitudinal axis of the trocar tube. The valve is controllable by an external lever which will hold the valve open or permit it to spring shut. An incremental advancement mechanism cooperates with the obturator to permit only incremental advance of the obturator. Instead of using a discrete shield component the shielding function may be provided by spring-loading the trocar tube itself to spring forward and shield the obturator tip after the tip penetrates tissue.

Claims

1. A trocar including:

(i) trocar tube having a proximal end and a distal end into which may be placed an obturator inserted into a safety shield,

(ii) an obturator having a cylindrical shaft attached to a perforating tip and extendable through said tube to perforate tissue at the distal end of the tube, said perforating tip having three cutting edges separated by three substantially flat surfaces, each of said substantially flat surfaces forming a face comprising a pair of diverging sides, each of said diverging sides intersecting at a cutting edge, and each of said flat surfaces intersecting along said cylindrical shaft in a smooth transition, and

(iii) a safety shield placed around said obturator and extendable to shield the tip of said obturator, both of said safety shield and said obturator emplaceable in said trocar tube, said shield exhibiting a rounded distal end with a slot for passage of said obturator tip therethrough, said slot bounded by three distally extending lobes formed on the distal end of said shield, the proximal end of said lobes opposing one another alongside each of the cutting edges of said perforating tip when said tip is extended through said slot, said slot generally conforming to the geometry of said perforating tip.

2. The trocar of claim 1 wherein said rounded distal end is hemispheric in profile.

3. The trocar of claim 1 wherein said slot extends radially to the outermost radial cutting edge of said obturator tip.

4. The trocar of claim 1 wherein each of said lobes has an inner surface which contacts a face of said perforating tip when said tip is extended through said slot.

5. The trocar of claim 1 further including resilient means located at the end of said safety shield enabling said safety shield to retract proximally to allow said perforating tip to be exposed at the distal end of said safety shield when force is exerted against the distal end of said safety shield.

6. The trocar of claim 5 further including a housing located at the proximal end of said safety shield, said housing including an abutment surface, and said safety shield including a proximal flange, wherein said resilient means is mounted for compression between said flange and said abutment surface.