Surgical obturator

• US 20090306698A1
• Filed: 06/03/2009
• Published: 12/10/2009
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Original Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Inventors: Mayenberger, Rupert, Maliglowka, Johann
• Granted Patent: US 8,105,348 B2
• Time in Patent Office: Days
• US Class Current: 606/185
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• 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 2017/3454 Details of tips
• CPC Class Codes: A61B 2017/3458 threaded
• CPC Class Codes: A61B 2090/08021 of the patient or his organs

Abstract

In a surgical obturator with a tubular housing, with a blade carrier displaceable in the tubular housing in the longitudinal direction between an advanced cutting position and a retracted protected position, a blade with a cutting edge being held on the blade carrier, the cutting edge being guided in a correspondingly extending guide of the tubular housing, with a protective cap engaging over the blade and being displaceable in the tubular housing in the longitudinal direction between an advanced rest position in which the blade is completely covered in its protected position and a retracted work position, the protective cap having a slit through which the cutting edge of the blade passes and, in the work position of the protective cap, projects over the latter, and with a retracting device arranged in the tubular housing and displacing the blade from the cutting position to the protected position, the retracting device being activatable by displacement of the protective cap from the work position to the rest position, in order to reduce the size of the retracting device, it is proposed that the retracting device comprise a switching element which fixes the blade in the cutting position and, upon activation, releases the blade for displacement to the rest position, the switching element being mounted in the tubular housing so as to be freely rotatable about the longitudinal axis of the tubular housing and immovable in the longitudinal direction, and the switching element being rotatable, upon displacement of the blade carrier and/or the protective cap in the longitudinal direction of the tubular housing, by means of a cam guide which is operative between the switching element, on the one hand, and the blade carrier and/or the protective cap, on the other hand.

Claims

1. Surgical obturator for piercing a body wall with a tubular housing, with a blade carrier displaceable in the tubular housing in the longitudinal direction between an advanced cutting position and a retracted protected position, a blade with a cutting edge being held on the blade carrier, the cutting edge being guided in a correspondingly extending guide of the tubular housing, with a protective cap engaging over the blade and being displaceable in the tubular housing in the longitudinal direction between an advanced rest position in which the blade is completely covered in its protected position and a retracted work position, the protective cap having a slit through which the cutting edge of the blade passes and, in the work position of the protective cap, projects over the latter, and with a retracting device arranged in the tubular housing and displacing the blade from the cutting position to the protected position, the retracting device being activatable by displacement of the protective cap from the work position to the rest position, wherein the retracting device comprises a switching element which fixes the blade in the cutting position and, upon activation, releases the blade for displacement to the rest position, the switching element being mounted in the tubular housing so as to be freely rotatable about the longitudinal axis of the tubular housing and immovable in the longitudinal direction, and the switching element being rotatable, upon displacement of the blade carrier and/or the protective cap in the longitudinal direction of the tubular housing, by means of a cam guide which is operative between the switching element, on the one hand, and the blade carrier and/or the protective cap, on the other hand.

2. Surgical obturator in accordance with claim 1, wherein the protective cap is acted upon by a spring which displaces the protective cap from the work position to the rest position.

3. Surgical obturator in accordance with claim 1, wherein the blade carrier is acted upon by a spring which displaces the blade carrier from the cutting position to the protected position.

4. Surgical obturator in accordance with claim 1, wherein the protective cap and the blade carrier are acted upon by a common spring which pushes these apart, the spring displacing the protective cap from the work position to the rest position and the blade carrier from the cutting position to the protected position.

5. Surgical obturator in accordance with claim 4, wherein the spring is a helical spring which is arranged in the interior of the blade carrier and is supported at one end on a projection of the protective cap that extends through the wall of the blade carrier into the interior thereof.

6. Surgical obturator in accordance with claim 1, wherein the cutting edge of the blade is of helical configuration, so that the blade carrier, upon displacement in the longitudinal direction relative to the tubular housing, and the protective cap, upon longitudinal displacement relative to the blade carrier, are rotated relative to each other about the longitudinal axis of the blade carrier.

7. Surgical obturator in accordance with claim 1, wherein the blade carrier comprises a sleeve-shaped shaft which is arranged concentrically with the tubular housing.

8. Surgical obturator in accordance with claim 1, wherein the blade carrier is connected to a push rod which extends through the tubular housing as far as a push device at the end of the tubular housing remote from the blade.

9. Surgical obturator in accordance with claim 1, wherein the switching element is a sleeve which concentrically surrounds the blade carrier.

10. Surgical obturator in accordance with claim 9, wherein the cam guide operative between the switching element and the blade carrier is formed by cam tracks and cams adapted to abut thereon, the cams and the cam tracks being arranged on the outer side of the blade carrier and on the inner wall of the sleeve-shaped switching element, respectively.

11. Surgical obturator in accordance with claim 10, wherein a plurality of similar cam tracks and cams are arranged along the circumference of the blade carrier and the sleeve-shaped switching element such that in successive work cycles the cams respectively abut on an adjacent cam track.

12. Surgical obturator in accordance with claim 10, wherein each cam track has associated with it two cams which, upon displacement of the blade carrier relative to the switching element, abut one after the other on the cam track.

13. Surgical obturator in accordance with claim 10, wherein the cam track is formed by the edge of an island-shaped projection.

14. Surgical obturator in accordance with claim 10, wherein a front cam facing the blade, upon displacement of the blade carrier from the protected position in the direction towards the cutting position, slides along a first section of the cam track that extends at an incline to the direction of displacement of the blade carrier and thereby rotates the switching element from an initial position in a first direction, and a rear cam facing away from the blade enters into abutment with a second section extending in the opposite direction at an incline to the direction of displacement of the blade carrier once the front cam has moved past the first section of the cam track, so that the switching element is rotated in the opposite direction into a blocking position in which, upon subsequent retraction of the blade carrier from an end position located in front of the cutting position, a stop arranged on the blade carrier strikes a stop on the switching element and thereby prevents any further retraction of the blade carrier.

15. Surgical obturator in accordance with claim 14, wherein the stop on the blade carrier is formed by the front cam.

16. Surgical obturator in accordance with claim 14, wherein the stop on the switching element is formed by a third section of the cam track that extends transversely to the longitudinal direction of the tubular housing.

17. Surgical obturator in accordance with claim 10, wherein the cam track and the cams between the switching element and the protective cap are formed by the side flanks of teeth which are arranged on the end faces of the protective cap and the switching element that face one another, and which are in engagement when the protective cap is retracted into the work position.

18. Surgical obturator in accordance with claim 14, wherein the flanks of the teeth are so arranged and designed that the teeth of the protective cap, upon retraction of the protective cap from the rest position to the work position, rotate the switching element from its blocking position in the first direction until the stop of the blade carrier reaches a fourth section of the cam track of the switching element, which extends at an incline to the longitudinal direction of the tubular housing and adjoins the stop of the switching element.

19. Surgical obturator in accordance with claim 18, wherein the flanks of the teeth are so designed that a rotation of the switching element in the second direction under the influence of the stop of the blade carrier abutting on the fourth section is limited such that the blade carrier, in relation to its position with the two stops abutting on each other, is retracted only slightly as far as its cutting position.

20. Surgical obturator in accordance with claim 19, wherein the engagement of the teeth of the blade carrier and the protective cap is released upon displacement of the protective cap into the rest position, so that the limitation of the rotatability of the switching element is eliminated.

21. Surgical obturator in accordance with claim 20, wherein the cam track has a fifth section which adjoins the inclined fourth section and along which the front cam of the blade carrier slides upon retraction of the blade carrier from the cutting position to the protected position and thereby rotates the switching element in the second direction into the initial position for the next work cycle.

22. Surgical obturator in accordance with claim 14, wherein when the switching element is located in the blocking position and the stop of the blade carrier is in abutment with the fourth section, the rear cam of the blade carrier is located opposite a sixth section of the cam track, which prevents a displacement of the blade carrier in the direction from the protected position to the cutting position.