The article examines the mechanisms of parallel and parallel-sequential structure, including specific translational-guides, flat, spherical mechanisms of a parallel structure with three degrees of freedom, modifications of Delta robots from various manufacturers. The most famous studies of robots of parallel-serial structure are presented. Mazor Renaissance and Mazor X robotic systems for robotic assistance during spinal surgery are examined. The method of synthesis of mechanisms of

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... ial structure with five degrees of freedom is briefly presented. Examples of synthesised schemes of mechanisms and three-dimensional schemes, synthesised using in the computer-aided design system Compass 3D, are given. A diagram of a mechanism of a parallel-sequential structure with five degrees of freedom for robotic assistance during minimally invasive operations, which can be used as an alternative to the da Vinci Surgical System Platform, is examined. An example of modelling the solution of the inverse problem of positions, direct and inverse problems of velocities and direct and inverse dynamic problems in the Mathcad system, the result of modelling the motion of the output link in various initial conditions is given. The results of experimental studies using a prototype mechanism are shown.