A device and method for motorized support of patient positioning are provided. Diagonally opposite corners of the support platform are rounded off so that the primary component is installable by insertion toward the elongated member at an angular orientation and rotation to engage the tabs in the slots. In addition, the system has an inverter operationally connected to the power source and the electric machine and configured to increase or decrease a rotor flux component of a voltage applied to the electric machine, while maintaining a torque component at an essentially constant level. The cutter is rotated and advanced linearly to cut a tissue sample which is then retrieved by retracting the needle. The rotary holding claw body has a pair of mutually opposing disk-shaped gripping claws, and the both disk-shaped gripping claws are forced to as to press push springs each other, and the fastening parts are gripped by the both disk-shaped gripping claws.