Abstract: A medical system includes: an endoscope; an ultrasonic probe; and a control device that is connected to the endoscope and the ultrasonic probe, generates a display image from a captured image acquired by the endoscope, and generates an echo image from an ultrasonic wave acquired by the ultrasonic probe, wherein the control device acquires a first echo image in which a target tissue is displayed on a central axis, acquires a second echo image obtained by scanning a cross section different from the first echo image at a reference position of the ultrasonic probe from which the first echo image was acquired, and compares a central axis of the second echo image with a position of the target tissue in the second echo image.

Abstract: A holding device is a holding device that holds the medical device, and includes an arm configured to have a holder, which holds the medical device, at a distal end, a base configured to rotatably support the arm by a first joint, a disk attached to the arm, and a brake attached to the base and configured to press the disk, in which a distance between a center of rotation of the disk and a region where the brake presses the disk is changed depending on a rotation angle of the first joint.

Abstract: A medical instrument holder for holding a medical instrument comprising: an adapter connected to a base portion via an arm; and an instrument holding portion configured to be capable of holding the medical instrument and connected to the adapter. The instrument holding portion includes: a positioning portion configured to perform positioning with respect to the adapter when mounted on the adapter; and a rod configured to be connected to the positioning portion and to be inserted into the adapter. The adapter includes: a contact portion to which an upper surface of the positioning portion contacts and which has an opening; a fitting hole configured to communicate with the opening of the contact portion and to extend in an insertion direction of the rod; and a window portion that is open to the fitting hole and is configured so that an insertion state of the rod can be visually recognized through the window portion when the positioning portion contacts to the contact portion.