A robotic medical apparatus includes a kinematic chain including a stand unit, an articulation device, a positioning device, and a positionable end effector. The apparatus further includes a controller to control the positioning device. The robotic medical apparatus includes a measurement system to determine a force and/or a torque. The force and/or the torque is essentially acting at one point in the kinematic chain. A measurement signal from the measurement system is transmittable to the controller. The controller is configured to determine the force and/or torque that is acting, and as a function of a current position and/or of a current kinematic state, to determine a nominal force and/or a nominal torque. As a function of the difference between the force that is acting and/or the torque that is acting that has been determined and the nominal force and/or the nominal torque that has been determined, a collision is detected.
