Tissue sampling device

Claim 1

A tissue sampling device comprising a needle assembly (1) with first, inner needle (3) slidably provided within a second hollow outer needle (2), said inner needle being provided with a hollow (3b) near its point for receiving a tissue sample, said device further comprising a housing (5), in which the needle assembly (1) is insertable, a propelling device (9) for propelling the inner needle (3), a propelling device (8) for propelling the outer needle (2), an energizing mechanism for biassing said propelling devices, and a release mechanism operable from the outside of the housing, and adapted to release said propelling devices, said energizing mechanism allowing positioning of and retaining both needles in a withdrawn position from without the needle assembly, said energizing mechanism comprising at least one energizing rod (23) displaceable in the longitudinal direction of the housing (5) and extending through an end wall (5d) thereof, thereby forming a handle (23a) thus enabling said energizing mechanism to be operable from the outside of the housing, said rod (23) being provided with slits (24, 25) cooperating with protrusions (26, 27) on first and second slides (7, 6) said first (7) and second (6) slides being coupled to said first (3) and second (2) needles respectively and running on guide rods (10a, 10b) located in the housing (5), such that when the energizing rod (23) is moved against the force of the propelling devices, the front edges of said slits (24, 25) become engaged with said protrusions (26, 27) whereby said slides (6, 7) are moved towards the energized position, thus biassing each respective propelling device (8, 9), said first and second slides (7, 6) being retained in their energized position by first (15, 16) and second (12, 14) hook means respectively, and said release mechanism provides for separate release of the two needles, said release mechanism comprising at least one biasable spring mechanism (8, 9) for each slide, whereby the bias force constitutes the driving force of the propelling means, the release mechanism further comprising means (18, 20, 16) for interrupting the engagement between said first hooks (15, 16) that retain the first slide (7) in its energized position, and for interrupting the engagement between said second hooks (12, 14) that retain the second slide (6) in its energized position, such that the first slide (7) is released first, and such that the first slide (7) after a predetermined time from its release, acts to release the second hook means (12, 14), thereby causing the second slide (6) to be released from its energized position.

Claim 3

The device according to any of claims 2 - 3, wherein the spring mechanism of each propelling device comprises at least one spring (8, 9), acting between the respective slides (6, 7) and the housing (5).