fig1 shows an endoscopic instrument 10 having a manipulating piece 12 , a manipulating element 14 and a flexible endoscope shaft 16 . it is to be appreciated that the explanations in the context of the disclosure apply to a rigid instrument shaft ( not shown ) as well . the endoscopic instrument 10 is used for examination and / or surgery purposes in medical procedures . the instrument shaft 16 has , not shown , an endoscope optic embodied as optical fibers , image - conducting cables , different channels , e . g . a suction and a cleaning channel , and an instrument channel . the instrument shaft 16 is proximally connected to the manipulating piece 12 and extends distally to a deflectable section 18 which is in particular an end section . it comprises an end piece 20 embodied as a terminating socket . the end piece 20 is the portion of the endoscope shaft 16 where the optical fibers , the image - conducting cables and the channels end . the endoscope shaft 16 is only partially shown in the figures . the manipulating piece 12 comprises a connection 22 , a supply cable 22 ′ and buttons 22 ″. the connection 22 leads to an instrument channel . through this channel instruments can be inserted into the endoscope shaft 16 all the way to the end piece 20 . this allows to perform surgeries in the area ahead of the end piece 20 . the supply cable 22 ′ contains different kinds of supplies , for example an electric supply , optical fibers , suction and cleaning lines and / or data lines . the image - generating process in the endoscopic instrument 10 is achieved via an imaging sensor , not shown , inside the manipulating piece 12 or in the end piece 20 , wherein the image data is routed externally via the supply cable 22 ′, in particular to a camera control unit ( ccu ), not shown . the manipulating element 14 is provided for controlling and deflecting the section 18 , wherein the corresponding handle 24 is shown which can be rotated in the directions of the couple - headed arrow 26 . by turning the manipulating element 14 the deflectable section 18 is being deflected up / down or left / right . each of the deflections correspond to the direction of rotation of the manipulating element 14 either clockwise or counterclockwise . as shown in fig2 a positioning element 30 having a first rotational axis 31 as well as an actuator 32 having a second rotational axis 70 are arranged in a proximal end portion 28 of the manipulating piece 12 . the positioning element 30 is connected to a pulling element 34 which extends through the endoscope shaft 16 and reaches into the end section 18 . the pulling element 34 is looped around the positioning element 30 and is embodied as one integral piece . further , an engaging element 36 which is a piece of the manipulating element 14 , is shown in the manipulating piece 12 . fig3 shows a detailed view of elements comprised in the endoscopic instrument 10 according to fig1 . it is shown that the positioning element 30 comprises a first gear ring 38 , the actuator 32 comprises a second gear ring 40 , and the first and second gear rings 38 , 40 are arranged such that their teeth are meshing . the actuator 32 further comprises an electric motor m , and the manipulating element 14 comprises a third gear ring 42 wherein the first and the third gear rings 38 , 42 are arranged such that their teeth are meshing . the result is that the manipulating element 14 and the actuator 32 are mechanically operationally connected with one another such that a force f exerted by the user onto the manipulating element 14 may at least partially be transmitted onto the actuator 32 . the handle 24 and the engaging element 36 of the manipulating element 14 are arranged such that they may be relatively displaced to one another . the handle 24 and the engaging element 36 are coupled to one another such that a displacement of the handle 24 may result in a displacement of the engaging element 36 . for the shown embodiment the displacements are rotational displacements . in order to achieve this the handle 24 and the engaging element 36 are arranged along a drive shaft 44 wherein the handle 24 may be rotatorily displaced relative to the engaging element 36 and the drive shaft 44 . in order to couple the displacement of the handle 24 and the displacement of the engaging element 36 the manipulating element 14 comprises a coupling arrangement 46 having a first part 48 and a second part 50 . for the embodiment shown the first part 48 is fixedly connected to the handle 24 and the second part 50 is fixedly connected to the engaging element 36 . the parts 48 , 50 are arranged and embodied such that a transmission of a force between the handle 24 and the engaging element 36 may be effected . the first part 48 comprises two elements 48 ′, 48 ″, and the second part 50 is embodied as a projection which is arranged between the two elements 48 ′, 48 ″. the first and second parts 48 , 50 are arranged relative to one another such that a displacement of the first part 48 may result in a displacement of the second part 50 . a first angle measuring device 52 is configured to provide an indication related to a first angle position of the manipulating element 14 or the handle 24 . a second angle measuring device 54 is embodied to provide an indication related to a second angle position of the positioning element 30 . a third angle measuring device 56 is configured to provide an indication related to a third angle position of the actuator 32 . a fourth angle measuring device 58 is configured to provide an indication related to a fourth angle position of the engaging element 36 . for the shown embodiment the angle measuring devices 52 , 54 , 56 , 58 are embodied as hall - sensors wherein only symbolically a corresponding magnet 52 ′, 54 ′, 56 ′, 58 ′ is shown . the hall - sensors are an example for a contactless angle measurement which is on its own an improvement over the prior art . the angle measurement may be performed in a contactless manner also via other means , in particularly capacitively or inductively . the endoscopic instrument 10 further comprises a control device 60 which is embodied to perform one , a plurality of or all of the following functions : the actuator 32 is driven by taking the first angle position and the second angle position into account . the actuator 32 is driven by taking the third angle position and the fourth angle position into account . the actuator 32 is driven by taking the first angle position and the fourth angle position into account . the actuator 32 is driven such that the positioning element 30 is maintained in a set position when the user does not exert a force f onto the manipulating element 14 . the actuator 32 is driven such that the actuator exerts a force onto the positioning element 30 which is at least in certain ranges at least approximately proportional to the force f which the user exerts onto the manipulating element 14 . the underlying functionality is as follows . it is assumed that the user exerts a force f onto the handle 24 into a counterclockwise direction ( when seen from the viewing perspective ). the control device 60 detects a change in the first angle positions and / or a difference between the first and the second angle positions . therefore it is detected that the user exerts a force f onto the handle 24 . at least a portion of the force f is transmitted onto the positioning element 30 . the control device 60 detects in which direction the user intends to displace the positioning element 30 , here in a clockwise direction , and drives the actuator 32 via the motor m correspondingly . in this particular case , this means that the third gear ring 42 is driven into a counterclockwise direction . in case of a fault of the actuator 32 , the first part 48 continues to transmit at least a portion of the force f onto the second part 50 , so that the portion of the force f is transmitted onto the positioning element 30 . at this point it is recalled that according to preferred embodiments the manipulating element comprises a first handle which displaces a first positioning element and a second handle which displaces a second positioning element . an actuation of the first handle results in a first movement of the section , in particular a movement left / right , and an actuation of the second handle results in a second movement of the section , in particular a movement up / down . preferably one of the handles is arranged on a hollow drive shaft in which a drive shaft of the other handle is arranged . therefore , certain embodiments may comprise two or more handles , positioning elements and actuators . fig4 shows a second embodiment of a coupling arrangement 46 having a force measuring device 60 ′, 60 ″. in a preferred embodiment the force measuring device 60 ′, 60 ″ indicates whether a force is exerted between the first part 48 and the second part 50 . in a further preferred embodiment the force measuring device 60 ′, 60 ″ provides for an indication related to the magnitude of a force exerted between the first part 48 and the second part 50 . preferably the first part 48 and the second part 50 are in direct contact via the force measuring device 60 ′, 60 ″, so that the user receives a feedback when actuating the manipulating element 14 . fig5 shows a third embodiment of a coupling arrangement 46 . in this embodiment a spring device 62 with spring elements 62 ′, 62 ″ is arranged at the first part so that a force between the first part 48 and the second part 50 is transmitted via the spring device 62 . fig6 shows the situation when the first part 48 has been displaced relative to the second part 50 . the second spring element 62 ″ is tensioned so that the user obtains a feedback . again , the actuator 32 is driven based on the angle information as previously explained . fig7 shows the rest position after the engaging element 36 has reached the position which the user has determined via the handle 24 . fig8 shows a further embodiment where the first and second rotational axes coincide by the actuator 32 being fixedly coupled on a common axis 64 with the positioning element 30 . the previously presented reference numerals and the corresponding explanations to the individual elements apply correspondingly . in contrast to the embodiment according to fig3 , no gear rings are required . further , the handle 24 is also arranged on the axis 64 via a bearing 66 . fig9 shows the embodiment according to fig8 in a view from the side . fig1 shows yet a further embodiment where the handle 24 and the positioning element 30 are arranged on a common axis 68 which is different from a rotational axis 70 of the actuator 32 . this embodiment may be easily implemented , however still provides the opportunity of arranging a reduction between the actuator 32 and the positioning element 30 , here , between the first gear ring 38 and the second gear ring 40 . the first and second rotational axes 31 , 70 are substantially parallel . fig1 shows the embodiment according to fig1 in a view from the side .
an endoscopic instrument includes a manipulating piece having a manipulating element , an instrument shaft having a section that is manipulable , wherein the shaft is coupled to the manipulating piece , a positioning element having a first rotational axis , a pulling element coupled to the positioning element and the section of the shaft , such that displacement of the positioning element actuates the section by transmitting a force via the pulling element , and an actuator coupled to the positioning element , such that actuation of the actuator displaces the positioning element by transmitting a force from the actuator to the positioning element . the manipulating element is coupled to the positioning element such that a force exerted onto the manipulating element transfers onto the positioning element and displaces the positioning element . the first rotational axis and a second rotational axis of the actuator are arranged at an angle less than 90 ° relative to one another .