Biopsy instruments and methods

A biopsy instrument comprising:

• a base member formed of an elongated hollow tube which extends from a proximal end to a distal end along a central geometrical axis, wherein the elongated hollow tube comprises:
• an inner elongated hollow tubular member, which has, at a distal portion thereof, a hollow elongated tubular sample acquiring portion having a smooth interior surface, and
• an outer elongated hollow tubular member,
• wherein the inner elongated hollow tubular member is arranged inside the outer elongated hollow tubular member and is rotationally and translationally movable relative to the outer elongated hollow tubular member,
• wherein a distal end of the inner elongated hollow tubular member is intended to be at least partly inserted into a tissue from which a biopsy is to be obtained,
• wherein the inner elongated hollow tubular member is capable of transferring a force along the central geometrical axis such that a movement of the proximal end along the central geometrical axis is transferred to a movement of the distal end along the central geometrical axis, and of transferring a torque about the central geometrical axis such that a rotation and a torque applied by a motor at the proximal end about the central geometrical axis is transferred from the proximal end to the distal end thereby rotating the distal end about the central geometrical axis,
• wherein the inner elongated hollow tubular member is provided with a distally facing circular cutting edge defining a mouth of the distal end of the hollow tube, wherein the distally facing circular cutting edge has as seen along a circumference of the mouth, a straight-line configuration, and the mouth defines a plane having a normal parallel to the extension of the central geometrical axis as the central geometrical axis passes through said plane of the mouth,
• wherein the hollow elongated tubular sample acquiring portion having a smooth interior surface has a length along the central geometrical axis being at least 10 times an inner diameter of the inner elongated hollow tubular member, and
• wherein the inner elongated hollow tubular member is airtight at least along the length of the tubular sample acquiring portion along the central geometrical axis,
• wherein the smooth interior surface of the hollow elongated tubular sample acquiring portion is smooth to such an extent that when a reference biopsy is to be acquired, the distally facing circular cutting edge and the distal end of the inner elongated hollow tubular member is configured to be advanced along the central geometrical axis into a tissue while being rotated by being motor driven at its proximal end and thereby cutting a core of the tissue which, due to the advancement of the inner elongated hollow tubular member, enters relative to the inner elongated hollow tubular member through the mouth into the sample acquiring portion of the inner elongated hollow tubular member with a circumferential outer surface of the core at least partly abutting the smooth interior surface of the sample acquiring portion, where-after the inner elongated hollow tubular member is retracted from the tissue while being rotated by being motor driven at its proximal end whereby the core of the tissue is detached from the tissue by a pulling force due to the retraction of the hollow tube and due to an adhesive force formed due to the smooth surface and the presence of liquid in the tissue at an interface between the smooth interior surface and the circumferential outer surface of the core which force keeps the core inside the sample acquiring portion having the smooth interior surface.