Compact robotic device and assemblies for manipulation of elongate surgical tools

A method for controlling linear movement of an elongate surgical tool at least partially received in a designated channel of a compact robotic device, comprising:

• positioning said elongate surgical tool at a first position within said designated channel inside the robotic device, wherein presence of said elongate surgical tool in said first position is detectable by one or more sensors located at said channel;
• positioning said elongate surgical tool at a second position within said channel, wherein at said second position said presence of said elongate surgical tool is not detectable by said one or more sensors;
• and
• upon receipt of a command to move said tool linearly along said channel, using said second position for calibrating movement of said tool.