Core biopsy arrangement
A core biopsy arrangement for taking a tissue sample from a human or animal tissue, preferably from a tumour or a suspected tumour, includes a needle holder member provided with a tissue sampling needle, a longitudinal movement element adapted to apply a longitudinal movement to the needle, wherein the movement of the needle is a reciprocating movement having a stroke length L, wherein the forward movement is faster than the retracting movement, and wherein the reciprocating movement is initiated when the distal end of the needle is subjected to a force in the longitudinal direction.
1. Core biopsy arrangement for
taking a tissue sample from a human or animal tissue, comprising a needle holder member provided with a tissue sampling needle configured to collect a core biopsy sample; and
a means for longitudinal movement configured to apply a longitudinal movement to the needle, the means for longitudinal movement being configured to have a forward movement including a primary movement followed by a secondary movement during a final part of the forward movement, wherein the longitudinal movement means is not attached to the needle such that during the primary movement the longitudinal movement means is not in contact with the needle and the longitudinal movement means contacts the needle during the secondary movement to apply forward movement to the needle, wherein
the longitudinal movement of the needle is a continuing reciprocating movement comprising alternating forward movements and retracting movements while entering the tissue,
the longitudinal movement having a variable stroke length,
a forward movement of the needle is faster than a retracting movement of the needle, and
the reciprocating movement of the needle is initiated when a distal end of the needle is subjected to a force in a longitudinal direction.
2. The core biopsy arrangement according to claim 1 , wherein the stroke length is linearly dependent of the force in the longitudinal and a proximal direction of the needle such that when a lower force is applied the stroke length is minimal and when a higher force is applied the stroke length is maximal.
3. The core biopsy arrangement according to claim 1 , wherein the arrangement further comprises a cylinder provided with a plunger adapted to move back and forth in said cylinder in dependence of applied air pressure pulses, said plunger is provided with a plunger rod adapted to cooperate with the proximal end of the needle when a force in the longitudinal and the proximal direction is applied to said needle.
4. The core biopsy arrangement according to claim 1 , wherein the movement is defined by a saw tooth movement, wherein the faster forward movement of the needle is discontinued instantaneously and followed by the slower retracting movement, wherein the velocities of the needle during the respective movements are constant.
5. The core biopsy arrangement according to claim 1 , wherein a velocity of the needle gradually increases during the forward movement and during the retracting movement, respectively.
6. The core biopsy arrangement according to claim 1 , wherein the arrangement further comprises means for control adapted to control the longitudinal movement.
7. The core biopsy arrangement according to claim 1 , wherein the longitudinal movement is applied when the needle is penetrating the tissue.
8. The core biopsy arrangement according to claim 1 , wherein the longitudinal movement is activated automatically.
9. The core biopsy arrangement according to claim 1 , wherein the longitudinal movement is activated manually.
10. The core biopsy arrangement according to claim 1 , wherein the needle is a coarse needle having a diameter of 1.2-3.2 mm.
11. The core biopsy arrangement according to claim 1 , wherein a length of the forward movement of the needle is 2-5 mm.
12. Core biopsy arrangement according to claim 1 , wherein a mean velocity of the forward movement of the needle is in the range of 8-80 m/s.
13. The core biopsy arrangement according to claim 1 , wherein the arrangement further comprises a means for suction adapted to remove a tissue sample from the distal end of the needle through a canal inside the needle by providing a suction force that enables transportation of the tissue sample, via the canal, towards the means for suction.
14. The core biopsy arrangement according to claim 13 , wherein a rod is provided in said canal that is adapted to be removed upon tissue sampling.
15. The core biopsy arrangement according to claim 1 , wherein the longitudinal movement is described by a Fourier series:
f
(
x
)
=
1
2
-
1
π
∑
n
=
1
∞
1
n
sin
(
n
π
x
L
)
where f(x) is the longitudinal position of the needle at time x, n is an integer from 1 to ∞ and L is the stroke length of the needle.
16. The core biopsy arrangement according to claim 15 , wherein n is 3 or greater.
17. The core biopsy arrangement according to claim 1 , wherein the human or animal tissue is from a tumour or a suspected tumour, a length of the forward movement of the needle is 3-4 mm, and a mean velocity of the forward movement of the needle is 30 m/s.
18. A core biopsy arrangement for taking a tissue sample from a human or animal tissue, comprising:
a needle holder member provided with a tissue sampling needle configured to collect a core biopsy sample; and
a longitudinal movement device including a plunger and cylinder configured to apply a longitudinal movement to the needle, the movement device being configured to have a forward movement including a primary movement followed by a secondary movement during a final part of the forward movement, wherein the movement device is not attached to the needle such that during the primary movement the movement device is not in contact with the needle and the movement device contacts the needle during the secondary movement to apply forward movement to the needle, wherein
the longitudinal movement of the needle os a continuing reciprocating movement comprising alternating forward movements and retracting movements while entering the tissue,
the longitudinal movement having a variable stroke length,
a forward movement of the needle is faster than a retracting movement of the needle, and
the reciprocating movement of the needle is initiated when a distal end of the needle is subjected to a force in a longitudinal direction.
19. The core biopsy arrangement according to claim 1 , wherein the stroke length of each stroke in one biopsy procedure is variable, and a maximal stroke length corresponds to a peak amplitude of the movement.
20. The core biopsy arrangement according to claim 18 , wherein the stroke length of each stroke in one biopsy procedure is variable, and a maximal stroke length corresponds to a peak amplitude of the movement.
21. A core biopsy arrangement for
taking a tissue sample from a human or animal tissue, comprising: a needle holder member provided with a tissue sampling needle configured to collect a core biopsy sample; and
a means for longitudinal movement configured to apply a longitudinal movement to the needle, the means for longitudinal movement being configured to have a forward movement including a primary movement followed by a secondary movement during a final part of the forward movement, wherein the longitudinal movement means is not attached to the needle such that during the primary movement the longitudinal movement means is not in contact with the needle and the longitudinal movement means contacts the needle during the secondary movement to apply forward movement to the needle, wherein
the longitudinal movement of the needle is a continuing reciprocating movement comprising alternating forward movements and retracting movements while entering the tissue,
the longitudinal movement having a variable stroke length,
a forward movement of the needle is faster than a retracting movement of the needle, and
the reciprocating movement of the needle is initiated when a distal end of the needle is subjected to a force in a longitudinal direction, and
the stroke length is linearly dependent of the force in the longitudinal and a proximal direction of the needle such that when a lower force is applied the stroke length is minimal and when a higher force is applied the stroke length is maximal.