Surgical instrument

A flexible robotic surgical instrument for mounting on a front end of a surgical robot arm, the surgical robot arm including an actuator, the flexible robotic surgical instrument comprising:

• a coupler comprising a driving wheel, the driving wheel configured to operate by a driving force transferred from the actuator;
• a shaft having one end thereof joined with the coupler and extending along a particular lengthwise direction, the shaft having a bendable bending part;
• an angle maintaining part being shaped as a tube that is bent by a preset angle, the angle maintaining part configured to hold the bending part therein and maintain an angled state of the bending part;
• and
• an effector for inserting into a body of a surgery patient, the effector joined to the other end of the shaft.

A medical trocar used in surgery using surgical instruments having bendable shaft, the trocar comprising:

• a trocar housing having a housing hole through which the shaft is inserted;
• and
• a tube-shaped cannula joined to the trocar housing, through which the shaft is inserted,
• wherein the cannula is bendable by a preset angle so as to hold a bent portion of the shaft therein and maintain a bent angle of the shaft.