Trocar

A surgical system comprising:

• a surgical instrument having an end tool with one or more joints, wherein the end tool is configured to rotate towards a direction of gravity from a shaft of the surgical instrument by a weight of the end tool;
• and
• a trocar comprising:
• a main body having a hollow portion formed therein to allow the surgical instrument to be inserted therethrough, the main body comprising a main body cap;
• a cannula detachably coupled to an end of the main body, and having a hollow portion formed therein to allow the surgical instrument to be inserted therethrough;
• an end tool mounting member which is detachably attached to the main body, and having an inclined portion formed on an inner circumferential surface thereof to allow the end tool of the surgical instrument to be mounted thereon;
• and
• an obturator configured to be detachably attached to the main body,
• wherein the main body cap is configured to be detachably attached to both of the end tool mounting member and the obturator, but the main body cap accommodates only one of the end tool mounting member and the obturator at a time,
• wherein the end tool mounting member is formed to have a conical shape, wherein the end tool mounting member is formed in an asymmetric conical shape in which distances from a center of the conical shape of the end tool mounting member to points of an edge of the conical shape of the end tool mounting member are different from each other,
• wherein a longest length of the inclined portion of the end tool mounting member is equal to or greater than a length of the end tool, and the surgical instrument is configured to be inserted into a body of a patient through the trocar, and
• wherein the end tool mounting member comprises a funnel main body, and the inclined portion of the end tool mounting member is rotatably coupled to the funnel main body.