Coaxial cannula provided with a sealing element

• US 20060229528A1
• Filed: 03/29/2004
• Published: 10/12/2006
• Est. Priority Date: 03/29/2003
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Heske, Thomas, Heske, Norbert
• Granted Patent: US 7,645,239 B2
• Time in Patent Office: Days
• US Class Current: 600/567
• CPC Class Codes: A61B 10/0233 Pointed or sharp biopsy instruments
• CPC Class Codes: A61B 10/0275 with sample notch, e.g. on the side of inner stylet
• CPC Class Codes: A61B 10/0283 with vacuum aspiration, e.g. caused by retractable plunger or by connected syringe A61B10/025, A61B10/0266 take precedence
• 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 17/3421 Cannulas
• CPC Class Codes: A61B 17/3462 with means for changing the diameter or the orientation of the entrance port of the cannula, e.g. for use with different-sized instruments, reduction ports, adapter seals expandable cannulas A61B17/3417
• CPC Class Codes: A61B 17/3474 Insufflating needles, e.g. Veress needles
• CPC Class Codes: A61B 17/3498 Valves therefor, e.g. flapper valves, slide valves haemostasis valves A61M39/06; check valves A61M39/24
• CPC Class Codes: G01N 1/08 involving an extracting tool, e.g. core bit

Abstract

The invention relates to a coaxial cannula (1) for extracting samples from tissue comprising a biopsy needle unit (9) provided with a space for sample extraction and a sample separation unit (21) which coaxially encompasses the biopsy needle (9) on an external wall and is longitudinally movable. The inventive coaxial cannula (1) comprises a sealing element (3) which is arranged on the proximal end thereof and closes the space between the internal wall of the coaxial cannula and the external wall of the sample separation unit. Said coaxial cannula (1) is characterised in that the sealing element (3) opens an air outlet when the biopsy needle unit (9) is inserted, and prevents air intake when the biopsy needle unit (9) is positioned and vacuum is produced in the internal chamber of the biopsy needle.

Claims

1. ) Coaxial cannula that can be used in tissue, in which for removing tissue are a biopsy needle unit with specimen removal space and a longitudinally movable specimen separating device that coaxially encloses the biopsy needle on the exterior wall, and whereby the coaxial cannula has on its proximal end a sealing element that encloses the space between the interior wall of the coaxial cannula and the exterior wall of the specimen separating device, characterized in that the sealing element (3) releases the air outlet when the needle unit is inserted and prevents air from entering after the needle unit has been positioned and a vacuum has been created in the biopsy needle interior space.

2. ) Coaxial cannula in accordance with claim 1, characterized in that a hose-type sealing element (3) is pushed over the proximal end of the coaxial cannula tube (1), the interior diameter of which is dimensioned so that it leaves open a slight gap between the sealing element and the biopsy needle unit (9), and in that the elasticity of the sealing element (3) is such that, given slight underpressure in the gap between the exterior wall of the needle unit (9) or the specimen separating device (21) and the interior wall of the coaxial cannula, the proximal end of the sealing element comes to act as a seal against the needle unit or the specimen separating device.

3. ) Coaxial cannula in accordance with claim 1 or 2, characterized in that when employing a biopsy device with a guide roller (13), provided on the distal surface of the guide roller is a stopper (14) with sealing elements (16, 17), which [stopper] is inserted into a counterpiece (15) on the proximal end of the cap of the coaxial cannula such that the opening is closed shortly prior to placing the distal surface of the guide roller on the proximal surface of the cap of the coaxial cannula.

4. ) Coaxial cannula in accordance with claim 1, characterized in that, when using an intermediate piece (18) between the distal end face of the guide roller with stopper (14) and the proximal end face of the cap with counterpart, the intermediate piece has on its proximal side a countercoupling part as a type of interior bore into which the stopper of the guide roller (13) with sealing elements is inserted and in that on the distal side the intermediate piece (18) has a stopper with sealing elements [sic] (19), which [stopper] is inserted into the proximal-side counterpiece of the cap of the coaxial cannula.