Surgical assist robot and method of controlling the same

A surgical robot comprising:

• a surgical instrument including a base disposed at a proximal end of the surgical instrument, a tool disposed at a distal end of the surgical instrument, and a shaft extending in an axial direction between the base and the tool;
• a manipulator configured to support the surgical instrument, the manipulator including an instrument interface to which the base of the surgical instrument is attached, an arm including rotational joints, and a prismatic joint coupling the instrument interface to a distal end of the arm;
• and
• a controller including a memory that stores a remote center that is a center of motion of the surgical instrument, wherein
• the controller is configured to control the motion of the manipulator such that with the shaft inserted through a trocar retained at a body wall of a patient and the tool located in a body cavity of the patient, a relationship (L−β)≤T1 (L+α) is established in a case of L≤T0,
• where:
• L represents an intra-body cavity length of the surgical instrument, the intra-body cavity length L being a length from the remote center to the distal end of the surgical instrument;
• T0 represents a maximum possible linear movement amount of the prismatic joint, the maximum possible linear movement amount T0 being an amount of movement from an origin position to an end point position;
• T1 represents a first linear movement amount of the prismatic joint, the first linear movement amount T1 being an amount of movement from the origin position to a current position;
• α represents a distance from the remote center to an inlet of the trocar;
• and β represents a distance from the remote center to an outlet of the trocar.

A method of controlling a surgical robot, the surgical robot including:

• a surgical instrument including a base disposed at a proximal end of the surgical instrument, a tool disposed at a distal end of the surgical instrument, and a shaft extending in an axial direction between the base and the tool;
• and a manipulator configured to support the surgical instrument, the manipulator including an instrument interface to which the base of the surgical instrument is attached, an arm including rotational joints, and a prismatic joint coupling the instrument interface to a distal end of the arm, the method comprising:
• storing a remote center that is a center of motion of the surgical instrument;
• receiving an operation for moving the surgical instrument;
• and
• controlling motion of the manipulator such that with the shaft inserted through the trocar and the tool located in a body cavity of the patient, a relationship (L−β)≤T1≤(L+α) is established in case of L≤T0,
• where:
• L represents an intra-body cavity length of the surgical instrument, the intra-body cavity length L being a length from the remote center to the distal end of the surgical instrument;
• T0 represents a maximum possible linear movement amount of the prismatic joint, the maximum possible linear movement amount T0 being an amount of movement from an origin position to an end point position;
• T1 represents a first linear movement amount of the prismatic joint, the first linear movement amount T1 being an amount of movement from the origin position to a current position;
• α represents a distance from the remote center to an inlet of the trocar;
• and β represents a distance from the remote center to an outlet of the trocar.

A surgical robot comprising:

• a surgical instrument including a base disposed at a proximal end of the surgical instrument, a tool disposed at a distal end of the surgical instrument, and a shaft extending in an axial direction between the base and the tool;
• a manipulator configured to support the surgical instrument, the manipulator including an instrument interface to which the base of the surgical instrument is attached, an arm including rotational joints, and a prismatic joint coupling the instrument interface to a distal end of the arm;
• and
• a controller including a memory that stores a remote center that is a center of motion of the surgical instrument, wherein
• the controller is configured to control the motion of the manipulator such that with the shaft inserted through a trocar retained at a body wall of a patient and the tool located in a body cavity of the patient, a relationship (T1+T2)≥L is established in case of L>T0,
• where:
• L represents an intra-body cavity length of the surgical instrument, the intra-body cavity length L being a length from the remote center to the distal end of the surgical instrument;
• T0 represents a maximum possible linear movement amount of the prismatic joint, the maximum possible linear movement amount T0 being an amount of movement from an origin position to an end point position;
• T1 represents a first linear movement amount of the prismatic joint, the first linear movement amount T1 being an amount of movement from the origin position to a current position;
• and T2 represents a second linear movement amount of the distal end of the arm, the second linear movement amount T2 being an amount of movement effected along the axial direction of the shaft by motion of at least one of the rotational joints of the arm.

A method of controlling a surgical robot, the surgical robot including:

• a surgical instrument including a base disposed at a proximal end of the surgical instrument, a tool disposed at a distal end of the surgical instrument, and a shaft extending in an axial direction between the base and the tool;
• and a manipulator configured to support the surgical instrument, the manipulator including an instrument interface to which the base of the surgical instrument is attached, an arm including rotational joints, and a prismatic joint coupling the instrument interface to a distal end of the arm, the method comprising:
• storing a remote center that is a center of motion of the surgical instrument;
• receiving an operation for moving the surgical instrument;
• and
• controlling motion of the manipulator such that with the shaft inserted through the trocar and the tool located in a body cavity of the patient, a relationship (T1+T2)≥L is established in case of L>T0,
• where:
• L represents an intra-body cavity length of the surgical instrument, the intra-body cavity length L being a length from the remote center to the distal end of the surgical instrument;
• T0 represents a maximum possible linear movement amount of the prismatic joint, the maximum possible linear movement amount T0 being an amount of movement from an origin position to an end point position;
• T1 represents a first linear movement amount of the prismatic joint, the first linear movement amount T1 being an amount of movement from the origin position to a current position;
• and T2 represents a second linear movement amount of the distal end of the arm, the second linear movement amount T2 being an amount of movement effected along the axial direction of the shaft by motion of at least one of the rotational joints of the arm.