This article deals with a patents state-of-the-art linked to our robotic system which holds an endoscope. In a first part, we analyze how the endoscope operates as well as we discover the environment where we wish to use it: the middle ear. In a second step, we establish a state-of-the-art on patents existing in the robotic and surgical fields. The approach is based on a specific search methodology using keywords and classifications. Thanks to all the patents found, we gather them according their country and date of publication, and we are able to analyze the results. This study brings to light technical solutions invented in recent years and allows us to find an innovative research axis.