FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to a system of minimal invasive intervention. System comprises a manipulator and a system for assessing the forces acting on the instrument during a surgical operation. Manipulator has a support configured to secure the trocar and to secure the actuator of the surgical instrument. Force evaluation system includes a three-axis lower strain gauge (2), a three-axis top strain gauge (1), a force sensor for capturing tool actuating surfaces and a sensor for rotating the surgical instrument. Three-axis lower strain gauge is located on support of manipulator in point of fixation of trocar and is in direct contact with it. Three-axis top strain gauge is located on the manipulator support under the surgical tool drive. Grip force sensor is made in the form of current sensor for electric motor of tool drive, which provides compression of actuating surfaces of tool. Torque sensor is made in the form of a current sensor for the electric motor of the tool drive, which provides rotation of the surgical tool around its longitudinal axis. Strain gauges are connected to digital data processing modules. Grip force sensor and torque sensor are connected with motor control systems. Digital processing modules and electric motor control systems are connected to a processing module which is programmed to perform the following calculation: forces directed along linear axes; rotary moments of the tool along the x and y axes relative to the trocar insertion point into the patient's body; the tool rotational moment along the z axis relative to the trocar insertion point into the patient's body; forces of compression of tool actuating surfaces. Each digital processing module is programmed to use a digital low-pass filter and a band-guard filter algorithm for said force, measured by a strain gauge. Processing module is programmed to: compensate for gravity acting on support of manipulator and tool; compensation of forces caused by