TECHNICAL FIELD

The present disclosure relates to a medical support arm apparatus, a medical system, and a surgical microscope system.

BACKGROUND ART

Recently, in the medical field, support arm apparatus are being used to support examinations and surgeries. For example, a system has been proposed in which an observation tool for observing a surgical site such as an endoscope or a microscope is supported by an arm section of a support arm apparatus, and a doctor carries out an examination or surgery while watching an image captured by the observation tool. Alternatively, another proposal has been made in which a treatment tool such as forceps or a retractor is provided on the front end of the arm section, and the support arm apparatus is made to support or perform operations with the treatment tool that have been performed manually in the past. Note that in the following description, an observation tool, treatment tool, and the like provided on the front end of the arm section of a support arm apparatus are collectively designated medical tools. Also, in the following description, a support arm apparatus in which an observation tool is provided on the front end of the arm section is also called an observation apparatus.

Generally, to control with high precision the position and attitude of a medical tool provided on the front end of an arm section, and also to improve operability for the user when moving the medical tool, many innovations for compensating the gravitational force due to the weight of the arm section itself (that is, innovations for canceling out the torque acting on each joint section due to the self-weight) are applied to the arm apparatus of the support arm apparatus. By compensating the gravitational force of the arm section, since the attitude of the arm section is maintained without being influenced by the gravitational force, highly precise positioning of the medical tool may be achieved. Also, by compensating the gravitational force of the arm section, since the user becomes able to operate the arm section as though it were weightless, operability for the user may be improved.

For example, as exemplified in Patent Literature 1, 2 and Non-Patent Literature 1, gravity compensation mechanisms that mechanically compensate the torque acting on the joint sections of an arm section due to self-weight are being developed. Specifically, Patent Literature 1 discloses a gravity compensation mechanism including a combination of a spring, a working gear, and a belt. Patent Literature 2 discloses a gravity compensation mechanism including a combination of a spring and multiple non-circular gears. Non-Patent Literature 1 discloses a gravity compensation mechanism including a combination of a spring and a non-circular pulley.

Also, as another technology for compensating the gravitational force of the arm section, a technology is known in which a counterweight is provided on the base end side of the arm section such that the arm section as a whole is balanced (that is, such that the weight of the arm section itself may be supported), and the support arm apparatus is configured as what is called a balance arm.

Alternatively, in a support arm apparatus, providing actuators in each joint section of the arm section and driving these actuators appropriately to cause the arm section to operate is known (for example, Patent Literature 3). In the case of a support arm apparatus having such a configuration, by causing an actuator provided in each joint section to operate to support the self-weight of the arm section, it becomes possible to compensate the gravitational force acting on the arm section.

CITATION LIST

Patent Literature

Patent Literature 1: JP 2012-240191APatent Literature 2: WO 2013/161006Patent Literature 3: WO 2015/046081

Non-Patent Literature

Non-Patent Literature 1: Gen Endo et al., “A Weight Compensation Mechanism with a Non-Circular Pulley and a Spring: Application to a Parallel Four-bar Linkage Arm”, Journal of the Robotics Society of Japan, The Robotics Society of Japan, January 2010, Vol. 28, No. 1, pp. 77-84

DISCLOSURE OF INVENTION

Technical Problem

Herein, with a mechanical gravity compensation mechanism as illustrated in Patent Literature 1, 2 and Non-Patent Literature 1, the gravitational force acting on the arm section is compensated by the restoring force of the spring, but the restoring force demanded of the spring to compensate the gravitational force changes depending on the attitude of the arm section. Consequently, with these mechanical gravity compensation mechanisms, the gravity compensation mechanism is configured such that the amount of stretch in the spring is adjusted appropriately depending on the attitude of the arm section, and the spring produces a suitable restoring force. Accordingly, the structure of the gravity compensation mechanism tends to be complicated, and there is a risk of reduced mass productivity from the perspectives of cost and reliability.

Also, in the case of configuring the support arm apparatus as a balance arm, providing a counterweight causes the apparatus to become bulkier and heavier. Consequently, a higher proportion of space in the operating room becomes occupied by the support arm apparatus, and the surgical work may be impeded. Also, because the weight of the apparatus as a whole becomes heavier, for example, in the case of configuring the support arm apparatus as what is called a hanging support arm apparatus in which the arm section hangs down from the ceiling, large-scale construction work becomes necessary, and there are concerns regarding increased costs for installation.

Also, in the case of performing gravity compensation with an actuator provided in each joint section of the arm section, since a larger output becomes demanded of the actuators provided on the base end side of the arm section, the actuators on the base end side become bulkier. Consequently, the support arm apparatus itself also becomes bulkier and heavier, and there are concerns that inexpediences similar to the case of providing a counterweight may occur. Also, because a larger output is demanded of the actuators, there is also a risk of increased power consumption.

Accordingly, the present disclosure proposes a novel and improved medical support arm apparatus, medical system, and surgical microscope system capable of performing gravity compensation with a more compact and lightweight configuration.

Solution to Problem

According to the present disclosure, there is provided a medical support arm apparatus including: an arm section including multiple joint sections, and configured such that a medical tool is provided on a front end; an actuator at least provided in a compensated joint section that is a target of gravity compensation among the joint sections, and including a torque sensor that detects a torque acting on the compensated joint section; and a gravity compensation mechanism that imparts to the compensated joint section a compensating torque in a direction that cancels out a load torque due to a self-weight of the arm section acting on the compensated joint section.

In addition, according to the present disclosure, there is provided a medical system including: a medical support arm apparatus including an arm section including multiple joint sections, and configured such that an observation tool for observing a surgical site of a patient is provided on a front end, an actuator provided in at least one of the joint sections and including a torque sensor that detects a torque acting on the joint section, and a gravity compensation mechanism that imparts, to each joint section provided with the actuator, a compensating torque that compensates a load torque caused by a self-weight of the arm section acting on the joint section, and a control apparatus that causes the actuator to operate on the basis of at least a state of the joint section detected by the torque sensor, and controls a driving of the joint section; and a display apparatus that displays an image captured by the observation tool of the medical support arm apparatus.

In addition, according to the present disclosure, there is provided a surgical microscope system including: an arm section including multiple joint sections that include actuators; a microscope for imaging a surgical site of a patient, provided on a front end of the arm section such that an imaging direction is changeable by controlling the actuators; a gravity compensation mechanism that imparts to a compensated joint section, which is a target of gravity compensation among the joint sections, a compensating torque in a direction that cancels out a load torque due to a self-weight of the arm section acting on the compensated joint section; and a display apparatus that displays an image captured by the microscope.

According to the present disclosure, a compensating joint section, which is a target for performing gravity compensation from among multiple joint sections included in an arm section, is provided with an actuator including a torque sensor that detects a torque acting on the compensating joint section, and a gravity compensation mechanism that exerts a compensating torque in a direction that cancels out a load torque caused by the self-weight of the arm section acting on the compensating joint section. Consequently, when driving the actuator on the basis of the torque acting on the compensating joint section detected by the torque sensor, gravity compensation can be performed by taking the compensating torque into account to cause the actuator to operate to generate a torque that works to cancel out the load torque. In other words, gravity compensation is performed by the combined use of the gravity compensation mechanism and the actuator. Consequently, compared to the case of performing gravity compensation with only a mechanical gravity compensation mechanism, the gravity compensation mechanism may have a simple configuration, while in addition, compared to the case of performing gravity compensation with only an actuator, the actuator may be configured more compactly. Thus, it becomes possible to perform gravity compensation while also configuring the arm section and the support arm apparatus in a more compact and lightweight configuration.

Advantageous Effects of Invention

According to the present disclosure as described above, it becomes possible to perform gravity compensation with a more compact and lightweight configuration. Note that the effects described above are not necessarily limitative. With or in the place of the above effects, there may be achieved any one of the effects described in this specification or other effects that may be grasped from this specification.

