Patent ID: 11890062
Assignee: RIVERFIELD INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 5:
6. An estimation method for estimating a pivot position of a surgical tool, a rear end side of which being held by a holder of an arm, the arm including at least one joint, the estimation method comprising:
obtaining vector information, which is information on an orientation of the holder of the arm or on an orientation of the surgical tool;
obtaining first information on a movement of a first position, which is a provisional pivot position of the surgical tool, and second information on a movement of a second position of the surgical tool, the second position being different from the first position;
calculating a direction of an axis of the surgical tool based on the vector information obtained, and individually calculating, based on the first information, the second information, and the direction of the axis of the surgical tool, a first perpendicular vector, which is a component of a vector in the movement of the first position, the component being perpendicular to the direction of the axis, and a second perpendicular vector, which is a component of a vector in the movement of the second position, the component being perpendicular to the direction of the axis;
calculating an inner product of the first perpendicular vector and the second perpendicular vector; and
updating a first distance, which is a length from a reference point on the rear end side of the surgical tool to the first position, or which is a length from a reference point on a front end side of the surgical tool to the first position, the front end side being opposite to the rear end side, by adding a value of the inner product multiplied by a specified coefficient to the first distance.