as per fig1 , a medical instrument r according to the invention has a hand - held module 1 , which consists of a grip part 2 and a guidance part 3 . a valve module 4 is inserted into one open end of the guidance part 3 and a cutting module 5 is inserted into the other open end . situated in the grip part 2 is a motor ( shown in fig4 ), with a bevel drive gear 7 being placed on the rotational shaft 6 thereof . this bevel drive gear 7 interacts with a ring bevel gear 8 , which surrounds a receptacle element 9 in the guidance part of the hand - held module 1 , with an annularly designed catching lug 10 engaging into a corresponding annular groove 11 in the receptacle element 9 . this annular groove 11 in turn forms an annular catching lug into the interior of the receptacle element 9 . in the usage position as per fig4 , the ring bevel gear 8 overlaps an outer gear ring 13 with an inner gear ring 12 , which outer gear ring 13 is placed on the cutting module 5 embodied as a cutting tube . this transmits rotational motion of the bevel drive gear 7 via the ring bevel gear 8 onto the outer gear ring 13 and the cutting module 5 is rotated about its longitudinal axis . in order to support the cutting module 5 during the rotation about its longitudinal axis , two spaced apart sliding rings 14 . 1 and 14 . 2 are placed on the cutting module 5 and these sliding rings in turn rotate in a front sliding bearing 15 . 1 and a rear sliding bearing 15 . 2 . moreover , it is possible to identify that the cutting module 5 is inserted in a detachable fashion into the hand - held module 1 or the receptacle element 9 by means of a connection with a catch mechanism . to this end , catch springs 16 project from the cutting module 5 between the rear sliding bearing 15 . 2 and the outer gear ring 13 , and said catch springs engage behind the catch groove 11 that projects inwards as a catch lug in the assembled state . after inserting the cutting module 5 into e . g . a human body for removing tissue , for example through a trocar , the motor 18 or the rotational shaft 6 thereof is set into rotational motion via a pushbutton 17 . in the process , the bevel drive gear 7 also rotates and drives the cutting module 5 , or sets the latter into rotational motion , via the ring bevel gear 8 , the inner gear ring 12 thereof and the outer gear ring 13 . in the process , the sliding rings 14 . 1 and 14 . 2 rotate in the corresponding sliding bearings 15 . 1 and 15 . 2 . the catch springs 16 engage behind the annular catching lugs projecting into the interior of the receptacle element 9 . should it be deemed necessary , a further surgical instrument can be inserted through a corresponding valve 19 in the valve module 4 , which surgical instrument can then also be routed through the cutting module 5 to the distal end thereof . according to the invention , a blade or a cutting element 20 with a blade 21 is situated at the distal end of the cutting module 5 . within the scope of the present invention , this cutting element 20 is made of spring steel and rolled together to form a sleeve . as per fig5 , an inner groove 22 is formed in a corresponding cutting module 5 . 1 for holding this cutting element 20 and so the cutting element 20 is inserted into the interior of the cutting module 5 . 1 . as per fig6 , a cutting module 5 . 2 has an outer groove 23 into which the cutting element 20 is inserted . that is to say in this case the cutting element 20 surrounds the distal end of the cutting module 5 . 2 . as per fig7 , the cutting element 20 is placed against a cutting module 5 . 3 in the form of a butt joint or is butt welded to this cutting module 5 . 3 .
a medical instrument for cutting biological tissue , a cutting module having a blade , wherein the cutting module is inserted into a hand - held module , the cutting module is detachably fixed in the hand - held module .