fig1 illustrates a total view of the reaming device according to an exemplary embodiment of the invention . the reaming device has a head portion denoted with a , an operator portion denoted with b and a shaft portion between the head portion and the operator portion . the head portion will be inserted through an orifice or channel of the human body in order to remove or ablate tissue by means of ablation devices 50 . the operator portion denoted with b remains outside the human body in order to allow the operator to handle the reaming device . for example , it is possible to remove the ablated tissue by sucking on a suction adapter or a suction device 2 , when an operator handles the reaming device , in particular the shaft 30 for modifying the geometry of the protruding amount of an ablation device , which protrudes beyond an outer surface of a head portion 40 . the head 40 portion is mounted on to a first shaft 10 , in particular , the head is pivoted with respect to the first shaft 10 . in the shown embodiment , a second shaft 20 is provided concentrically within the first shaft in order to drive the head 40 . the head 40 is mounted to one end 18 of the first shaft 10 , and with a second end 19 of the first shaft 10 , the first shaft is mounted to the suction adapter 2 . thus , a reaming device 1 may be provided , which allows an operator to modify the geometry of a protruding amount of an ablation device by means , for example , of a third shaft 30 . fig2 illustrates a detailed picture of a longitudinal cross - section of the head 40 of the reaming device 1 . the head portion denoted with a comprises a first shaft 10 , a second shaft 20 being concentrically formed within the first shaft and a third shaft 30 provided concentrically within the second shaft 20 in the present embodiment . the head 40 may be mounted to the top portion 18 of the first shaft 10 by means of an adapter plug 102 , which may also serve as a gasket or seal . the ablation device 50 may comprise , for example , an ablation wire 51 , which protrudes with a protrusion a mount 55 beyond a surface 41 of the head 40 . the protrusion wire may extend through a hole or opening 42 being formed in the head 40 of the reaming device 1 . the head 40 may be pivoted or rotated around a longitudinal axis 13 of the shaft geometry , so that also the protruding amount 55 rotates in order to ablate tissue . the protruding amount 55 extends at least partially laterally in radial direction 56 with respect to the longitudinal axis 13 of the device . however , the protruding amount 55 may also extend partially in a longitudinal direction 57 , i . e . into the direction of the longitudinal axis 13 . further , openings 42 , 43 may be provided in order to allow removal of ablated tissue . these openings 43 , 42 may be provided close to the ablation device 50 in order to allow removal of tissue immediately after ablating the tissue . the tissue may be removed by transporting the ablated tissue through the conduit 70 , wherein the conduit 70 is functionally connected with its first end 78 to the openings or recesses 42 , 43 to allow removal of the ablated tissue . the conduit may be formed by an inner wall 12 of the first shaft 10 and an outer wall 21 of second shaft 20 or may be formed by an inner wall 12 of the first shaft and an outer wall 31 of the third shaft 30 . the latter case is applicable in case there is no second shaft provided . the coupling of the second shaft to the head 40 may be provided via an adapter device 101 . fig3 illustrates an exploded view of the reaming device 1 . the first shaft 10 is provided with the bearing , sealing and / or grommet device 102 . the second shaft 20 is connected to the adapter device 101 in order to provide a connection to the head 40 . within the second shaft 20 , there is provided the third shaft 30 on top of which , a block 103 may be provided in order to provide a reliable positioning of the ablation device 50 . in the embodiment shown in fig3 , the ablation device comprises two ablation wires 51 . the ablation wires , or in general , the ablation device 50 , will be inserted into the head 40 , so that the ablation wires 51 extend through the recesses or holes 42 . the recesses 42 and 43 will serve for removal of the ablated tissue . a detailed geometry can be seen from the longitudinal cross - section of fig2 or the perspective view of fig4 . it should be noted , that the number of ablation devices , e . g . ablation wires is not limited to the number of two , but may also be only one or alternatively more than two ablation devices . fig4 illustrates a perspective view of the assembled head portion of the reaming device 1 . in the embodiment shown in fig1 , the first shaft 10 is connected to the head 40 via the device 102 serving as a sealing , bearing , and / or grommet . the adapter device 101 connects the second shaft being provided concentrically within the first shaft 10 , to the head 40 . the ablation wires 51 extend beyond the surface 41 of the head 40 by a protruding amount 55 . the geometry of the protruding amount may be remotely modified by moving the third shaft 30 for example in longitudinal direction , so that when pushing the third shaft 30 , the protruding amount 55 of the protruding wires 51 will extend in a larger amount over the surface 41 of the head 40 . it should be noted that the modification may also be carried out by a relative rotating and a gear , e . g . a screw or worm gear ( not shown ). recesses 43 allow removal of the ablated tissue . therefore , the recesses 43 may be provided close to the protruding amount of the protruding wires 51 . the arrows illustrate the flow of the ablated tissue from the proximity of the ablation wire 51 through the head portion through the recesses or openings 43 into the conduit 70 . the conduit 70 is formed by the inner surface 12 of the first shaft 10 and the outer surface 21 of the second shaft 20 . it should be noted that also the holes 42 through which the ablation device is conducted may serve as a recess to remove tissue . it should be noted that the geometry of the ablation wires 51 may also be of a different geometry , in particular if modifying the tip geometry with respect to the requirements of the ablation application . fig5 illustrates the head 40 with the ablation device 50 inserted into the holes 42 of the head 40 , here in form of ablation wires 51 . the ablation wires 51 extend at least partially in a lateral direction 56 beyond the surface of the head 40 , however they may also extend in a longitudinal direction 57 . the block 103 restricts the movement of the ablation device and constitutes the transit from the ablation wires 51 to the third shaft 30 . fig6 illustrates a suction adapter 2 , which may be connected to the end portion 79 of the conduit 70 . the suction adapter 2 comprises , for example , a spout 105 to be connected to a vacuum pump , not shown . the second shaft may be connected to a drive , wherein the bushing may be sealed with a seal or grommet 104 . the third shaft 30 may be formed concentrically within the second shaft . the handling devices or the driving devices for the second shaft 20 and the third shaft 30 are not shown . fig7 illustrates a perspective view of the suction adapter 2 of fig6 . the end portion 79 of the conduit 70 is connected to the body of the suction adapter or suction device 2 , so that the ablated tissue may be removed by a suction process . the ablated tissue will move along the arrows through the spout 105 . the position of the second shaft 20 and a third shaft 30 may be fixed by a screw 106 . fig8 illustrates an embodiment including a gear providing a connection between the ablation device and the third shaft , not shown in fig8 . the ablation device shown in fig8 comprises rigid or hard ablation tips or blades 52 , which are pivoted mounted by a hinge 54 so that the rotation of the ablation device 50 is not locked when hitting a rigid obstacle , for example , an implant or the like . the gear wheel portions 200 engage into recesses 202 of a rod 204 which may be moved in the longitudinal direction , and which may be directly connected to the third shaft for modifying the geometry ( diameter ) of the ablation device . it should be noted that the gear wheel portions rotate along an axis perpendicular to the longitudinal axis of the device when being operated by the third shaft , which third shaft being moved into longitudinal direction of the device , i . e . the shaft extension . the tips or blades 52 of the ablation device 50 may rotate around a hinge 54 , having a rotational axis being substantially parallel to the longitudinal axis of the device , if the device is in the position shown in fig8 . however , the rotational axis of the hinges 54 may be inclined , when the geometry of the ablating device 50 will be modified by moving the rod with the recesses along a longitudinal axis of the device . similar to the previous embodiments , there may be provided recesses or openings 43 in order to remove tissue to be transported through the conduit 70 . fig9 illustrates the device of fig8 when being assembled with a head 40 , so that the mechanical parts are covered to avoid injury of the surrounding tissue or to avoid damages of the mechanical components . it should be noted that the term ‘ comprising ’ does not exclude other elements or steps and the ‘ a ’ or ‘ an ’ does not exclude a plurality . also elements described in association with different embodiments may be combined . it should be noted that the reference signs in the claims shall not be construed as limiting the scope of the claims . although the invention herein has been described with reference to particular embodiments , it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention . it is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims .
a bone reamer has an ablation device for forming cavities in body tissue , the ablation device is movable with respect to a head of the reamer , and is capable of protruding at least partially beyond a surface of the head . the amount of protrusion the ablation device protrudes beyond the surface of the head has a variable geometry and the geometry is remotely modifiable . more particularly , the amount the ablation device extends beyond the outer surface of a reamer head body can be varied by an actuator located on the reamer outside the body .