Patent Publication Number: US-2023149107-A1

Title: Medical operation apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of International Patent Application No. PCT/JP2020/026766 filed on Jul. 8, 2020, in the Japan Patent Office, the contents of which being incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates to a medical operation apparatus that allows to reflect a grasping operation performed by an operator. 
     2. Description of Related Art 
     In recent years, endoscopic surgery using a master-slave type surgical assist robot has become widely available. Here, the master means a medical operation apparatus that remotely controls a slave, and the slave means a surgical device that performs surgery in accordance with instructions from the master. 
     The above-described surgical assist robot has a configuration in which in response to an operator moving a grip of the master, slave forceps are moved in conjunction with the grip. However, it is difficult operators with different finger sizes and finger lengths to properly reflect a content of the movement resulting in unintentional operation. 
     SUMMARY 
     It is an aspect to provide a medical operation apparatus which may easily inhibit an unintentional operation from being reflected in the medical operation apparatus. 
     According to an aspect of one or more embodiments, there is provided a medical operation apparatus comprising a body to be grasped by an operator; an operation part arranged to enable at least a part of the operation part to be moved, by the operator, closer to and away from the body; and a holder configured to hold fingers of the operator grasping the body, the holder being configured to transmit a movement of the fingers to the operation part. The holder comprises a contact portion configured to be in contact with the body when the operation part is moved closer to the body, and a connector supporting a relative posture of the holder and the operation part so as to change the relative posture in accordance with a posture change of the fingers of the operator, wherein, in a relative arrangement position of the operation part and the body with which the contact portion is in contact, when the relative posture of the holder and the operation part is changed, an amount of change in the relative arrangement position of the body and the operation part is within a specified permissible range. 
     According to another aspect of one or more embodiments, there is provided a medical operation apparatus comprising a body; an operation part connected to the body such that at least a portion of the operation part is movable with respect to the body; and a finger holder configured to receive fingers of an operator who grasps the body, the finger holder configured to transmit a movement of the fingers to the operation part and comprising a contact portion configured to contact with the body when the operation part is moved toward the body, and a connector rotatably supporting the contact portion, wherein, when the operation part contacts the body and a relative posture of the finger holder and the operation part is changed, an amount of change in a relative position of the body relative to the operation part is within a threshold range. 
     According to yet another aspect of one or more embodiments, there is provided a medical operation apparatus comprising a body including a shaft and a cylindrical grip attached to one end of the shaft; an operating part movable relative to the body; a finger holder that is slidable along the operating part, the finger holder comprising a connector, and a contact portion that is rotatably connected to the connector and that contacts the shaft of the body when the operating part is moved relative to the body, wherein, when the contact portion contacts the shaft, the contact portion is rotatable such that a distance between a central axis of the connector and a contact point between the contact portion and the shaft remains constant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects will become apparent and more readily appreciated from the following description of various embodiments, taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a block diagram showing one example of an overall configuration of a surgical assist robot, according to some embodiments; 
         FIG.  2    is a perspective view showing an overview of a medical operation apparatus, according to some embodiments; 
         FIG.  3    is another perspective view showing an overview of the medical operation apparatus, according to some embodiments; 
         FIG.  4    is a plan view showing an overview of the medical operation apparatus, according to some embodiments; 
         FIG.  5    shows an example of a holder, according to some embodiments; 
         FIG.  6 A  and  FIG.  6 B  show the holder before and after movement, according to some embodiments; 
         FIG.  7 A  and  FIG.  7 B  show, respectively, the medical operation apparatus according to some embodiments, and a medical operation apparatus in a modified example, according to some embodiments; 
         FIG.  8 A  and  FIG.  8 B  show a movement of a medical operation apparatus according to the related art as a comparative example; 
         FIG.  9    shows an overview of a medical operation apparatus in a modified example, according to some embodiments; and 
         FIG.  10    shows an overview of a medical operation apparatus in a modified example, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As described above, a surgical assist robot may have a configuration in which in response to an operator moving a grip of the master, slave forceps are moved in conjunction with the grip. Therefore, the operator who operates the master-slave type surgical assist robot can operate the forceps of the surgical assist robot at will as if the forceps are part of him/herself. Specifically, a medical operation apparatus may allow an operator to hold a body so as to wrap the body with his/her palm, place his/her fingers onto an engagement portion of an operation part, and move his/her fingers in this state, thereby reflecting the content of the movement. 
     However, in the above-described medical operation apparatus, a distance between the body and the engagement portion is fixed. Thus, it is difficult for operators with different finger sizes and finger lengths to properly reflect the content of the movement. 
     It is conceivable to provide an adjustment mechanism to adjust the distance between the body and the engagement portion arranged in the operation part. However, if the adjustment mechanism is moved by an unintentional operation by the operator and the operation part is moved in conjunction with the movement of the adjustment mechanism, the content of the movement is reflected based on the unintentional movement of the operation part. As a result, the slave may be remote-controlled based on the unintentional operation by the operator. 
     In one aspect of the present disclosure, it is advantageous to easily inhibit the unintentional operation from being reflected in the medical operation apparatus that is the master. 
     According to some embodiments, a medical operation apparatus may be configured to acquire an operation performed by an operator, the medical operation apparatus comprising a body, an operation part, and a holder. The operator grasps the body. The operation part is arranged so as to enable at least a part of the operation part to be moved closer to and away from the body by the operator. The holder is configured to hold fingers of the operator grasping the body, and the holder is configured to transmit a movement of the fingers to the operation part. The holder comprises a contact portion and a connector. The contact portion is configured to be in contact with the body when the operation part is moved closer to the body. The connector supports a relative posture of the holder and the operation part so as to change the relative posture in accordance with a posture change of the fingers of the operator. In the relative arrangement position of the body with which the contact portion is in contact and the operation part, when the relative posture of the holder and the operation part is changed, an amount of change in the relative arrangement position of the body and the operation part is within a specified permissible range. 
     According to this configuration, the connector supports the relative posture of the holder and the operation part so as to change the relative posture in accordance with the posture change of the fingers of the operator. Therefore, the device is configured to be available for multiple operators with different finger sizes. 
     Furthermore, in a state where the contact portion is in contact with the body, even if the operator performs an unintentional operation due to a force applied to the fingers and the posture of the operator&#39;s fingers and the relative posture of the holder and the operation part are changed, the amount of change in the relative arrangement position of the body and an operation part is within the specified permissible range. 
     This configuration makes it possible to inhibit the operation part from moving equal to or more than the permissible range even if the unintentional operation is performed by the operator, and makes it easy to inhibit the operation part from moving equal to or more than the permissible range. As a result, in the medical operation apparatus that is the master, it is easier to inhibit the unintentional operation by the operator from being reflected. 
     According to some embodiments, a sensor may be configured to detect the relative arrangement position of the operation part to the body. The permissible range may be less than a minimum value of an amount of change, detectable by the sensor, between the body and the operation part. 
     In this configuration, the permissible range is set to less than the minimum value of the amount of change detectable by the sensor. Thus, it is possible to inhibit the operation part from moving equal to or more than the minimum amount of change detectable by the sensor even if the operator performs the unintentional operation. This configuration makes it easy to inhibit the detector from detecting the unintentional operation by the operator as a grasping operation. 
     According to some embodiments, the contact portion may comprise a convex surface formed into a convex shape, and the amount of change in the relative arrangement position of the body and the operation part, based on a variation in a distance between the convex surface and a center of a posture change of the holder in the connector, may be within the specified permissible range. 
     In this configuration, the amount of change in the relative arrangement position of the body and the operation part, based on the variation in the distance between the convex surface of the contact portion and the center of the posture change of the holder in the connector, is within the specified permissible range. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     According to some embodiments, the contact portion may comprise contact flat surfaces, and the amount of change in the relative arrangement position of the body and the operation part, based on a variation in a distance between each of the contact flat surfaces and a center of a posture change of the holder in the connector, may be within the specified permissible range. 
     In this configuration, the amount of change in the relative arrangement position of the body and the operation part, based on the variation in the distance between each of the flat surfaces of the contact portion and the center of the posture change of the holder in the connector, is within the specified permissible range. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     According to some embodiments, the body comprises a concave surface formed into a concave shape in an area to be in contact with the contact portion, and when the contact portion is in contact with the concave surface, the amount of change in the relative arrangement position of the body and the operation part, based on a variation in a distance between the concave surface and a center of a posture change of the holder in the connector, may be within the specified permissible range. 
     In this configuration, when the contact portion is in contact with the concave surface formed into a curved surface in the body, the amount of change in the relative arrangement position of the body and the operation part, based on the variation in the distance between the concave surface and the center of the posture change of the holder in the connector, is within the specified permissible range. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     According to some embodiments, the body may comprise body flat surfaces forming a concave shape in the area to be in contact with the contact portion, and when the contact portion is in contact with any of the body flat surfaces, the amount of change in the relative arrangement position of the body and the operation part, based on a variation in a distance between each of the body flat surfaces and a center of a posture change of the holder in the connector, may be within the specified permissible range. 
     In this configuration, when the contact portion is in contact with the concave surface formed by the flat surfaces in the body, the amount of change in the relative arrangement position of the body and the operation part, based on the variation in the distance between each of the body flat surfaces and the center of the posture change of the holder in the connector, is within the specified permissible range. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     According to some embodiments, the operation part may be formed into a long shape, and the connector connects the holder and the operation part so that an arrangement position of the holder along a longitudinal direction of the operation part having a long shape is changeable. 
     In this configuration, the connector connects the holder and the operation part so that an arrangement position of the holder along the longitudinal direction of the operation part having a long shape is changeable. Therefore, the arrangement position of the holder can be varied relative to the operation part in accordance with the size or the like of the operator&#39;s fingers. 
     1. CONFIGURATION 
     The surgical assist robot  1  may be a master-slave robot for endoscopic surgery and the like. The surgical assist robot  1  includes a master device and a slave device. The operation that has been reflected in the master device is transmitted to the slave device by communications, and the slave device works. 
     The surgical assist robot  1  will be described with reference to  FIG.  1   . 
     The surgical assist robot  1  comprises a master device  100 , a controller  200 , and a slave device  300 . 
     A medical operation apparatus  101  is a part of the master device  100 , and is configured to detect a grasping operation performed by an operator, including a medical worker. The medical operation apparatus  101  is configured to be able to reflect at least the grasping operation performed by the operator. The detector  10 A is configured to detect the operation performed by the operator with a sensor arranged in a body, for example. 
     The controller  200  is configured to control the slave device  300  based on the operation performed by the operator that has been detected by the medical operation apparatus  101 . The controller  200  comprises various control structures and control methods in accordance with the configuration of the slave device  300 . 
     The slave device  300  is a slave-side device in the surgical assist robot  1 , and is configured to perform a grasping action based on the control by the controller  200 . For example, the slave device  300  may be a pair of forceps. Examples of a target grasped by the slave device  300  may include blood vessels and/or organs of a patient&#39;s body. 
     The target grasped by the slave device  300  is not limited to the blood vessels or the organs of the patient&#39;s body, and may include various targets that can be grasped by the slave device  300 . 
     Here, in addition to the grasping operation performed by the operator, the medical operation apparatus  101  may detect operations to move the slave device  300  and to change the posture of the slave device  300 . Thus, the controller  200  may control the movement and the posture change of the slave device  300  in addition to the grasping action. The medical operation apparatus  101  is configured to be operated by the operator&#39;s right hand; however, the medical operation apparatus  101  may be configured to be operated by the left hand. 
       FIG.  2    is a perspective view showing an overview of a medical operation apparatus, according to some embodiments.  FIG.  3    is another perspective view showing an overview of the medical operation apparatus, according to some embodiments.  FIG.  4    is a plan view showing an overview of the medical operation apparatus, according to some embodiments.  FIG.  5    shows an example of a holder, according to some embodiments. 
     As shown in  FIG.  1    to  FIG.  5   , the medical operation apparatus  101  according to some embodiments comprises a body  10 , an operation part  20 , a holder  30 , a rotating portion  40 , a detector  10 A, and a supporting portion  50 . The illustration of the structure in which the medical operation apparatus  101  is connected to the master device  100  is omitted in  FIGS.  1 - 5   . 
     The body  10  is a part to be grasped by the operator. The body  10  comprises a long portion  12  formed into a long shape such as a columnar shape, and a grip  13  protruding from an end of the long portion  12 . In some embodiments, the long portion  12  may be a bar, a shaft, or a beam. In the body  10 , the grip  13  is formed at one end of the long shape. The body  10  is configured to be held by the operator with the grip  13  being grasped. 
     Hereinafter, a longitudinal direction of the long portion  12  is assumed as a y-axis direction. The direction from the end with the grip  13  to the other end in the long portion  12  is assumed as a positive direction of the y-axis. An extending direction of the grip  13  perpendicular to the y-axis direction is assumed as a z-axis direction. The direction away from the long portion  12  is assumed as a positive direction of the z-axis direction. A direction perpendicular to each of the y-axis direction and the z-axis direction is assumed as an x-axis direction. The x-axis, the y-axis, and the z-axis are configured in accordance with a right-handed coordinate system. 
     The grip  13  is formed into a substantially columnar shape. In some embodiments, the grip  13  may be, for example, a cylindrical shaft. 
     The peripheral surface of the grip  13  may be formed into a shape easily held by the operator&#39;s right hand. Specifically, the peripheral surface of the grip  13  may have a concave shape suitable for the shape of the right hand. 
     The grip  13  comprises a supporting portion  50  that is arranged near the long portion  12  and that has a long shape extending toward a substantially x-axis negative direction. The supporting portion  50  comprises a first end that is on a grip  13  side and that is connected to the grip  13 . The supporting portion  50  comprises a second end that is opposite the first end and that comprises a rotating portion  40 . 
     The operation part  20  is used to reflect the grasping operation performed by the operator. The operation part  20  has a long shape extending from the rotating portion  40 . In some embodiments, the operation part may be, for example, a beam, a rod, or a shaft. 
     The rotating portion  40  is arranged between the supporting portion  50  and the operation part  20  and comprises a rotation axis extending in the substantially z-axis direction. The rotating portion  40  allows the supporting portion  50  and the operation part  20  to relatively move around the rotation axis. The rotating portion  40  rotates around the rotation axis, thereby enabling a change in the angle formed by a longitudinal direction of the supporting portion  50  and a longitudinal direction of the operation part  20 . 
     In other words, when the operation part  20  rotates around the rotation axis of the rotating portion  40 , the operation part  20  moves around the rotation axis. Due to the rotation, the operation part  20  moves closer to or away from the body  10 . 
     The detector  10 A is configured to detect the angle formed by the longitudinal direction of the supporting portion  50  and the longitudinal direction of the operation part  20 . The detector  10 A is configured to output, to the controller  200 , the detected angle as a detection signal. The detector  10 A may be arranged any position as long as the detector  10 A can detect the angle formed by the longitudinal direction of the supporting portion  50  and the longitudinal direction of the operation part  20 . The detector  10 A is an angle sensor for measuring the angle formed by the longitudinal direction of the supporting portion  50  and the longitudinal direction of the operation part  20 . The detector  10 A may be a rotary encoder or other angle sensors. 
     The holder  30  is configured to hold fingers of the operator grasping the body  10 . The holder  30  is configured to transmit, to the operation part  20 , the movement of the fingers. The holder  30  is provided to the operation part  20 , and is configured such that the arrangement position thereof can be changed along the longitudinal direction of the operation part  20 . In other words, the holder  30  may slide along the operation part  20 . In operation, a hand of the operator may grasp the body  10  such that the operator&#39;s palm would contact the grip  13 , the operator&#39;s thumb would rest on the body  10  and the operator&#39;s fingers would wrap around and contact the holder  30 . 
     The holder  30  comprises a connector  31 , a contact portion  33 , and a transmitting 
     portion  35 . 
     The connector  31  is connected to the operation part  20 . The connector  31  may be connected to the operation part  20  so that the holder  30  is movable along the longitudinal direction of the operation part  20 . In other words, the operation part  20  may slide along the beam, rod, or shaft. 
     The connector  31  has a rotation axis along the substantially z-axis direction. The rotation axis allows the contact portion  33  and the transmitting portion  35  to rotate relative to the connector  31 . 
     The connector  31  supports a relative posture between the contact portion  33 /the transmitting portion  35  and the operation part  20  so as to change the relative posture in accordance with the posture change of the fingers on the operation part  20 . 
     When the operation part  20  comes closer to the long portion  12  of the body  10 , the contact portion  33  is in contact with a body right surface  11  of the long portion  12 . The body right surface  11  of the body  10  as used herein is the right surface of the body  10 , i.e. a side surface located on an x-axis negative side. 
     Specifically, the contact portion  33  is arranged so as to be positioned on an x-axis positive side relative to the connector  31 . When positioned on the x-axis positive side, the contact portion  33  comprises a convex surface  33   a  formed into a convex shape that is swelled in an x-axis positive direction. That is, the contact portion  33  comprises the convex surface  33   a  outwardly convex relative to the connector  31  of the holder  30 . 
     The convex surface  33   a  is, for example, a circumferential surface with a rotation axis of the connector  31  as a central axis. That is, in a cross sectional view perpendicular to the central axis, the central axis and each point on the convex surface  33   a  are arranged so that a distance therebetween is substantially constant. Here, the arrangement is not limited to the one in which the distance between the central axis and each point on the convex surface  33   a  is constant. Specifically, the convex surface  33   a  may be formed so that a variation in the distance between the central axis and each point on the convex surface  33   a  is within the permissible range R. 
     Here, an example of the permissible range R may be a range in which the amount of change in angle between the long portion  12  of the body  10  and the operation part  20 , based on the variation in the distance between the central axis and each point on the convex surface  33   a,  is less than a minimum value of the amount of change in angle detectable by the detector  10 A. 
     The transmitting portion  35  is a flat portion to be in contact with the operator&#39;s finger, e.g. the index finger. The transmitting portion  35  is a surface opposite the contact portion  33  of the holder  30 . That is, in the holder  30 , the transmitting portion  35  is located opposite the contact portion  33  relative to the connector  31 . 
     2. ACTION 
       FIGS.  6 A- 6 B  show states where the holder  30  rotates around the rotation axis of the connector  31  while the contact portion  33  of the holder  30  is in contact with the body right surface  11  of the long portion  12  of the body  10 . For example, when the holder  30  rotates around the rotation axis of the connector  31 , the state thereof changes between a state shown in  FIG.  6 A  and a state shown in  FIG.  6 B . 
     In the state of  FIG.  6 A , on a surface of the convex surface  33   a,  a point in contact with the body right surface  11  is assumed as a first contact point P 1 , and a distance from the center of the rotation axis of the connector  31  to the first contact point P 1  is assumed as a first contact distance D 1 . When the holder  30  is rotated around the rotation axis of the connector  31 , in the state of  FIG.  6 B  and on the surface of the convex surface  33   a,  a point in contact with the body right surface  11  is assumed as a second contact point P 2 , and a distance from the center of the rotation axis of the connector  31  to the second contact point P 2  is assumed as a second contact distance D 2 . 
     Here, the convex surface  33   a  is formed into a shape that is a circumferential surface around the rotation axis, and thus, the first contact distance D 1  and the second contact distance D 2  are the same. In other words, between the state shown in  FIG.  6 A  and the state shown in  FIG.  6 B , a distance between the center of the rotation axis and the body  10  does not change even if the holder  30  is rotated around the rotation axis of the connector  31 . Therefore, a distance between the operation part  20  connected by the connector  31  and the body  10  also does not change due to the rotation. 
     That is, the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between the convex surface  33   a  and the central axis that is the center of the posture change of the holder  30  in the connector  31 , is within a specified permissible range R. In the relative arrangement position of the body  10  in contact with the portion  33  and the operation part  20 , when the relative posture of the holder  30  and the operation part  20  are changed, the amount of change in the relative arrangement position of the body  10  and the operation part  20  is within the specified permissible range R. 
     The detector  10 A detects a change in the grasping operation based on the amount of change in the relative arrangement position of the body  10  and the operation part  20 . Thus, the detector  10 A does not detect a change in the grasping operation performed by the operator. As a result, there is no change in the control by the controller  200 , which performs the control based on the change in the grasping operation detected by the detector  10 A. Therefore, there is no change in the control of the slave device  300  in response to the rotation. 
     That is, even if the holder  30  is rotated by an unintentional operation due to a force applied to the operator&#39;s finger touching the transmitting portion  35  in a state where the contact portion  33  of the holder  30  is in contact with the body  10 , it is easy to inhibit a change in the grasping by the slave device  300 . 
     3. EFFECTS 
     In the medical operation apparatus  101 , the connector  31  comprises the rotation axis, and the holder  30  rotates around the rotation axis, thereby making it possible to cope with the posture change of the fingers. 
     This configuration allows the connector  31  to support the relative posture of the holder  30  and the operation part  20  so as to change the relative posture in accordance with the posture change of the operator&#39;s fingers. 
     The connector  31  is arranged so as to be movable along the longitudinal direction of the operation part  20 , and thus adjustable for multiple operators with different finger sizes. 
     Furthermore, in a state where the contact portion  33  is in contact with the body  10 , there is a possibility that the operator may perform an unintentional operation due to a force applied to the fingers, and the posture of the operator&#39;s fingers and the relative posture of the holder  30  and the operation part  20  may be changed. When the relative posture of the holder  30  and the operation part  20  is changed, the distance between the rotation axis of the connector  31  and the contact point is unchanged against the change in the position of the contact point. That is, the amount of change in the relative arrangement position of the body  10  and the operation part  20  is within the specified permissible range R. 
     This configuration makes it possible to inhibit the operation part  20  from moving equal to or more than the permissible range R when the unintentional operation by the operator is performed, and makes it easy to inhibit the operation part  20  from moving equal to or more than the permissible range R. 
     Specifically,  FIG.  8    shows a comparative example, in which the holder  130  is formed into a rectangular parallelepiped shape and a body  110  comprises a flat side surface in a part to be in contact with a contact portion  133  of the holder  130 . In the case shown in  FIG.  8   , the holder  130  rotates around the connector  131  in a contact state as shown in  FIG.  8 A  and  FIG.  8 B . Then, with the rotation of the holder  130 , a leading end of the operation part  120  is moved. When a sensor of a detector detects this movement, a controller controls the slave device  300  in accordance with the grasping operation detected by the detector. 
     Thus, in the contact state, when the holder  130  is rotated around the connector  131  by the unintentional operation by the operator, the slave device  300  is controlled based on the unintentional operation, and the slave device  300  will perform an unintentional operation. 
     The type of surgery for which the surgical assist robot  1  may be used is not particularly limited. However, when the surgical assist robot  1  is used for surgery requiring an operation to grasp targets that are different in hardness, such as blood vessels and organs, an unintentional operation is especially likely to occur. Therefore, the surgical assist robot  1  is suitable for use in surgery requiring an operation to grasp targets that are different in hardness. 
     In some embodiments, even if the unintentional operation by the operator is reflected in the state where the holder  30  is in contact with the body  10 , the amount of change in the relative arrangement position of the body  10  and the operation part  20  is within the specified permissible range R. 
     This configuration makes it possible to inhibit an unintentional grasping operation from being reflected in the detector  10 A. As a result, it is possible to easily inhibit the slave device  300  from performing an unintentional operation based on the unintentional grasping operation. 
     4. MODIFIED EXAMPLES 
     (1) In some embodiments, the convex surface  33   a  forms the circumferential surface around the central axis of the connector  31 . However, the shape of the convex surface  33   a  is not limited to the circumferential surface around the central axis of the connector  31 . For example, the connector  31  may be configured to have a specified center point and form a spherical shape around the center point like a sphere joint or a ball joint. 
     Furthermore, in some embodiments, the distance from the central axis of the connector  31  to the convex surface  33   a  is constant in a cross section perpendicular to the central axis of the connector  31 . However, in some embodiments, the distance from the central axis of the connector  31  to the convex surface  33   a  is not necessarily constant, and may be varied within the permissible range R. Here, in some embodiments, the permissible range R is exemplified as a range in which the amount of change in angle between the long portion  12  of the body  10  and the operation part  20 , based on the variation in the distance between the central axis and each point on the convex surface  33   a,  is less than the minimum value of the amount of change in angle detectable by the detector  10 A. That is, the permissible range R is set to a value less than the minimum value of the amount of change detectable by the detector  10 A. 
     Thus, it is possible to inhibit the operation part from moving equal to or more than the minimum value of the amount of change detectable by the detector  10 A in response to the unintentional operation by the operator. This configuration makes it easy to inhibit the detector  10 A from detecting the unintentional operation by the operator as the grasping operation. 
     In other words, the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between the convex surface  33   a  of the contact portion  33  and the center of the posture change of the holder  30  in the connector  31 , is within the specified permissible range R. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     (2) In some embodiments, as shown in  FIG.  7 A , the contact portion  33  comprises the convex surface  33   a  that is a circumferential surface. However, in some embodiments, the configuration is not limited to the one comprising the circumferential surface. As shown in  FIG.  7 B , the contact portion  33  may comprise holder-side contact flat surfaces  33   b - 33   e.  The variation in a distance between each of the holder-side contact flat surfaces  33   b - 33   e  and the central axis of the connector  31  that is the center of the posture change of the holder  30  in the connector  31  may be within the permissible range R. 
     That is, based on the variation in the above distance, the variation in the distance between the central axis of the connector  31  and the body  10  may be configured to be within the permissible range R in a state where one of the holder-side contact flat surfaces  33   b - 33   e  of the contact portion  33  is in contact with the body  10  and a in state where any other surface is in contact with the body  10 . 
     With this configuration, the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between each of the holder-side contact flat surfaces  33   b - 33   e  of the contact portion  33  and the center of the posture change of the holder  30  in the connector  31 , is within the specified permissible range R. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     Note that the number of the holder-side contact flat surfaces  33   b - 33   e  is not limited to four as shown in  FIG.  7   , and in some embodiments, the number may be four or more and four or less. 
     (3) In some embodiments, a configuration has been explained in which the operator operates the device with the right hand. However, the medical operation apparatus  101  is not limited to the configuration applied to the right-handed operation. That is, in some embodiments, the device may be applicable to a left-handed operation. In this case, for example, each component constituting the medical operation apparatus  101  may be relatively arranged so as to be operated with the left hand. Specifically, the components of the medical operation apparatus  101  may be arranged to have a positional relationship that is mirrored relative to a y-z flat surface. 
     (4) In some embodiments, the sensor of the detector  10 A is an angle sensor. However, in some embodiments, the sensor of the detector  10 A is not limited to the angle sensor. The sensor may be any sensor that can detect the arrangement position of the operation part  20  relative to the body  10 . For example, various kinds of sensors including a position sensor may be used. 
     (5) In some embodiments, the contact portion  33  of the holder  30  comprises the convex surface  33   a.  This configuration makes it possible not to change the distance between the body  10  and the operation part  20  even if the holder  30  rotates around the central axis of the connector  31  in response to the posture change of the operator&#39;s fingers in a state where the convex surface  33   a  is in contact with the body  10 . However, the configuration in which the distance between the body  10  and the operation part  20  does not change is not limited to the configuration in which the holder  30  comprises the convex surface  33   a.    
     For example, as shown in  FIG.  9   , in some embodiments, the body  60  may be formed to comprise, on a body right surface  61  of the body  60 , a concave surface  63   a  concavely formed in an area to be in contact with the contact portion  33 . The shape of a contact portion  73  of a holder  70  may be formed into a shape corresponding to the concave surface  63   a  of the body  60 . 
     Specifically, the concave surface  63   a  may be formed into a shape allowing the distance between a contact point and the rotation axis of the connector  71   a  to be constant assuming that a point where the concave surface  63   a  is in contact with the contact portion  73  as the contact point when the contact portion  73  of the holder  70  is in contact with the concave surface  63   a.  The holder  70  may be formed into a shape, such as a rectangular parallelepiped shape, in which the contact portion  73  does not comprise the convex surface  33   a,  for example. 
     That is, the concave surface  63   a  may be configured such that the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between the concave surface  63   a  and the center of the posture change of the holder  30  in the connector  31 , is within the permissible range R when the contact portion  73  of the holder  70  is in contact with the concave surface  63   a.    
     With this configuration, when the contact portion  33  is in contact with the concave surface  63   a  formed into a curved surface in the body  10 , the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between the concave surface  63   a  and the center of the posture change of the holder  30  in the connector  31 , is within the specified permissible range R. 
     This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     The concave surface  63   a  is not limited to a shape allowing a distance between the contact point and the rotation axis of the connector  71  to be constant assuming that the point where the concave surface  63   a  is in contact with the contact portion  73  as the contact point when the contact portion  73  of the holder  70  is in contact with the concave surface  63   a.  That is, the shape of the concave surface  63   a  may be any shape if the variation in the distance between the contact point and the connector  71  of the rotation axis is within the permissible range R. 
     (6) Furthermore, as shown in  FIG.  10   , in some embodiments, the body  10  may comprise body contact flat surfaces  63   b - 63   g  forming a concave shape in an area to be in contact with the contact portion  33 . When the contact portion  33  is in contact with any of the body contact flat surfaces  63   b - 63   g,  the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between each of the body contact flat surfaces  63   b - 63   g  and the center of the posture change of the holder  30  in the connector  31 , may be within the specified permissible range R. 
     The distance between each of the body contact flat surface  63   b - 63   g  and the center of the posture change of the holder  30  in the connector  31  as used herein may mean, for example, a length of a perpendicular line drawn from each of the body contact flat surfaces  63   b - 63   g  towards the central axis of the connector  31 . 
     In this configuration, when the contact portion  33  is in contact with the concave surface consisting of the body contact flat surfaces  63   b - 63   g  of the body  10 , the amount of change in the relative arrangement position of the body  10  and the operation part  20 , based on the variation in the distance between each of the body contact flat surfaces  63   b - 63   g  and the center of the posture change of the holder  30  in the connector  31 , is within the specified permissible range R. This configuration makes it is easy to inhibit the unintentional operation by the operator from being reflected as the grasping operation. 
     (7) Note that the number of the body contact flat surfaces  63   b - 63   g  is not limited to six as shown in  FIG.  10   , and in some embodiments, the number may be six or more and six or less. 
     (8) A plurality of functions of one element of the aforementioned embodiments may be performed by a plurality of elements, and one function of one element may be performed by a plurality of elements. Furthermore, a plurality of functions of a plurality of elements may be performed by one element, and one function performed by a plurality of elements may be performed by one element. A part of the configurations of the aforementioned embodiments may be omitted. Furthermore, at least a part of the configurations of the aforementioned embodiments may be added to or replaced with the configurations of the other above-described embodiments. 
     (9) Other than the medical operation apparatus  101  and the surgical assist robot  1 , the present disclosure may also be embodied in various forms, such as a system comprising the medical operation apparatus  101  and the surgical assist robot  1 , a program to functionalize a computer as the medical operation apparatus  101  and the surgical assist robot  1 , a non-transitory tangible recording medium such as a semiconductor memory storing the program, and a method for operating the medical operation apparatus  101  and the surgical assist robot  1 . 
     It should be understood that embodiments are not limited to the various embodiments described above, but various other changes and modifications may be made therein without departing from the spirit and scope thereof as set forth in appended claims.