A medical device according to the present invention comprises a fixed platform (4) mounted on an extension arm (1), wherein on said platform (4) there are six motors with encoders (5), wherein shafts (6) of three said motors with encoders (5.1, 5.2, 5.3) are connected to a first mobile platform (12.1) by means of connecting assemblies, and shafts (6) of the remaining three motors with encoders (5.4, 5.5, 5.6) are connected to a second mobile platform (12.2) by means of connecting assemblies. Each connecting assembly comprises a first arch connector (7) with an angle range of 90 degrees, whose first end is directly and rigidly connected to the shaft (6) of the respective motor with an encoder (5.1, 5.2, 5.3, 5.4, 5.5, 5.6), and whose second end is connected to a first end of a second arch connector (9) by means of a joint (8) with three degrees of freedom, and the second end of the second arch connector (9) has at the end thereof a transverse arch arm (10) and is rotatably connected (11) to said mobile platform (12.1, 12.2) having a form of three rotational rings (13) mounted on a holder (14) of a medical instrument. The holder (14) of a medical instrument has a form of a telescopic pipe element. The motors with encoders (5) are so mounted on the fixed platform that the axes of rotation of the shafts (6, 6) of each group of three motors with encoders (5) intersect at one point at an angle of 120 degrees.
