The task of this assignment is development of instruments for brain biopsy. It presents the ideas and concepts of the brain tumor biopsy tool. Also it presents a procedure aimed at creating a functional concept of a tool which meets the requirements of the tasks. At the beginning products and patents on the market were studied, in order to come up with a valid idea, and after that, ideas and sketches of the concept were presented. The task begins with a review of existing patents and products on the market. Although these are patents and products for breast biopsy, they have been considered because these patents are considered useful for further work. Chapter 4 presents four concepts from which the best one concept is selected. A linear stroke would be performed with a single drive or with a combination of two drives. The advantages and disadvantages of using one or a combination of two drives are discussed. Chapter 5 provides an overview of some linear motion drives found. In Chapter 6, the rotary drives are analyzed and a standard planetary gear and drive are selected and the product price is shown. Chapters 7 and 8 elaborate in detail the upper and lower assembly of the selected concept and create a model in the program SolidWorks 2017- also individual assembly drawings and manufacturing drawings of individual parts of the assembly.