Abstract:
A probe includes a probe distal end body, a vibration transmission body and a heat dissipation unit. The probe distal end body includes a first electrode. The vibration transmission body is arranged to a proximal end of the probe distal end body. The vibration transmission body transmits ultrasonic vibration generated by an ultrasonic transducer to the probe distal end body, and transmits current to the first electrode. An interior surface of the probe distal end body and an interior surface of the vibration transmission body define an interior space. The heat dissipation unit dissipates heat generated at the probe distal end body, wherein at least a portion of the heat dissipation unit is arranged in the interior space defined by the probe distal end body and the vibration transmission body. A treatment instrument includes the probe and an end effector including a second electrode.

Description:
BACKGROUND 
       [0001]    The present invention relates to a surgical operation apparatus which performs therapeutic treatment, such as incision, resection or coagulation, of a living body tissue by making use of ultrasonic and composite energy of ultrasonic and high-frequency waves. 
       SUMMARY 
       [0002]    This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. 
         [0003]    A probe according to a first aspect of the invention is provided. The probe comprises: a probe distal end body comprising a first electrode; a vibration transmission body arranged to a proximal end of the probe distal end body, wherein the vibration transmission body is configured to transmit ultrasonic vibration generated by an ultrasonic transducer to the probe distal end body, and to transmit current to the first electrode, and wherein an interior surface of the probe distal end body and an interior surface of the vibration transmission body define an interior space; and a heat dissipation unit configured to dissipate heat generated at the probe distal end body, wherein at least a portion of the heat dissipation unit is arranged in the interior space defined by the probe distal end body and the vibration transmission body. 
         [0004]    A treatment instrument according to a second aspect of the invention is provided. The treatment instrument comprises: a probe comprising: a probe distal end body comprising a first electrode of a pair of bipolar electrodes, wherein the first electrode is electrically connected to a first electric path through which an electric current is transmitted; a vibration transmission body arranged to a proximal end of the probe distal end body, wherein the vibration transmission body is configured to transmit ultrasonic vibration generated by an ultrasonic transducer to the probe distal end body, and to transmit the electric current to the first electrode, and wherein an interior surface of the probe distal end body and an interior surface of the vibration transmission body define an interior space; a heat dissipation unit configured to dissipate heat generated at the probe distal end body, wherein at least a portion of the heat dissipation unit is arranged in the interior space defined by the probe distal end body and the vibration transmission body; and an end effector configured to move relative to the probe distal end body to change a distance between the end effector and the probe distal end body, wherein the end effector comprises a second electrode of the pair of bipolar electrodes, the second electrode being configured to be electrically connected to a second electric path through which the electric current is transmitted. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view that schematically shows the entire structure of an ultrasonic therapeutic apparatus according to a first embodiment of the present invention; 
           [0006]      FIG. 2  is a perspective view showing a disassembled state of the ultrasonic therapeutic apparatus according to the first embodiment, with coupling sections of assembly units of the ultrasonic therapeutic apparatus being disconnected; 
           [0007]      FIG. 3  is a side view showing a coupled state between a handle unit and a transducer unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0008]      FIG. 4  is a longitudinal cross-sectional view showing an internal structure of the transducer unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0009]      FIG. 5  is a plan view showing a probe unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0010]      FIG. 6  is a cross-sectional view taken along line VI-VI in  FIG. 5 ; 
           [0011]      FIG. 7  is a plan view showing a distal end portion of the probe unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0012]      FIG. 8A  is a longitudinal cross-sectional view showing a distal end portion of a sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0013]      FIG. 8B  is a plan view showing a jaw of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0014]      FIG. 9A  is a longitudinal cross-sectional view showing a proximal end portion of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0015]      FIG. 9B  is a cross-sectional view taken along line IXB-IXB in  FIG. 9A : 
           [0016]      FIG. 10  is a side view showing an attachment section of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment: 
           [0017]      FIG. 11  is a perspective view showing a state in which the jaw of the ultrasonic therapeutic apparatus according to the first embodiment is opened: 
           [0018]      FIG. 12  is a perspective view showing, in a direction different from the direction in  FIG. 11 , the state in which the jaw of the ultrasonic therapeutic apparatus according to the first embodiment is opened: 
           [0019]      FIG. 13  is a perspective view showing a hold member of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0020]      FIG. 14  is a side view showing a jaw body of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0021]      FIG. 15  is a side view showing an electrode member of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0022]      FIG. 16  is a side view showing an insulation member of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0023]      FIG. 17  is a plan view showing an engaged state between the electrode member of the jaw and the probe distal end portion of the ultrasonic therapeutic apparatus according to the first embodiment. 
           [0024]      FIG. 18  is a vertical cross-sectional view showing an engaged state between the electrode member of the jaw and the probe distal end portion of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0025]      FIG. 19  is a plan view showing a living body tissue contact surface of the hold member of the jaw of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0026]      FIG. 20  is a plan view showing the probe distal end portion of the ultrasonic therapeutic apparatus according to the first embodiment: 
           [0027]      FIG. 21  is a longitudinal cross-sectional view showing a driving pipe of the ultrasonic therapeutic apparatus according to the first embodiment: 
           [0028]      FIG. 22  is a perspective view showing a distal end portion of the driving pipe of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0029]      FIG. 23  is a plan view showing the driving pipe of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0030]      FIG. 24  is a cross-sectional view taken along line  24 - 24  in  FIG. 23 ; 
           [0031]      FIG. 25  is a front view showing the driving pipe of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0032]      FIG. 26  is a longitudinal cross-sectional view showing a state before a threaded pin is engaged in an assembly section at the proximal end portion of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0033]      FIG. 27  is a perspective view showing the state before the threaded pin is engaged in the assembly section at the proximal end portion of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0034]      FIG. 28  is a longitudinal cross-sectional view showing the state in which the threaded pin is engaged in the assembly section at the proximal end portion of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0035]      FIG. 29  is a perspective view showing a state prior to rotational engagement at the time when the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment are coupled: 
           [0036]      FIG. 30  is a plan view showing the state prior to rotational engagement at the time when the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment are coupled: 
           [0037]      FIG. 31  is a perspective view showing a state after the rotational engagement at the time when the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment are coupled; 
           [0038]      FIG. 32  is a plan view showing the state after the rotational engagement at the time when the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment are coupled: 
           [0039]      FIG. 33  is an explanatory view for explaining a positional relationship between a guide groove and an engaging recess portion at the coupling section between the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0040]      FIG. 34  is a perspective view showing a connection tube body of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0041]      FIG. 35  is a perspective view showing the connection tube body of the sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0042]      FIG. 36  is a side view showing a state before an attachment member is attached to a base member of a stationary handle of the handle unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0043]      FIG. 37  is a longitudinal cross-sectional view showing a state after engagement between the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0044]      FIG. 38  is a cross-sectional view taken along line  38 - 38  in  FIG. 37 ; 
           [0045]      FIG. 39  is a cross-sectional view taken along line  39 - 39  in  FIG. 37 ; 
           [0046]      FIG. 40  is a cross-sectional view taken along line  40 - 40  in  FIG. 37 ; 
           [0047]      FIG. 41A  is a vertical cross-sectional view showing a state prior to engagement of the engagement section between the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0048]      FIG. 41B  is a vertical cross-sectional view showing a state prior to engagement of the engagement section between the handle unit and sheath unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0049]      FIG. 42  is a cross-sectional view taken along line  42 - 42  in  FIG. 37 ; 
           [0050]      FIG. 43  is a perspective view showing an electrode hold member of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0051]      FIG. 44  is a front view showing the electrode hold member of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0052]      FIG. 45  is a side view showing the electrode hold member of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0053]      FIG. 46  is a cross-sectional view taken along line  46 - 46  in  FIG. 37 ; 
           [0054]      FIG. 47  is a cross-sectional view taken along line  47 - 47  in  FIG. 37 : 
           [0055]      FIG. 48  is a cross-sectional view taken along line  48 - 48  in  FIG. 37 ; 
           [0056]      FIG. 49  is a perspective view showing an electrode member of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0057]      FIG. 50  is a transverse cross-sectional view showing the electrode member of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0058]      FIG. 51  is a cross-sectional view taken along line  51 - 51  in  FIG. 37 ; 
           [0059]      FIG. 52  is a schematic view showing an internal structure of a cable of the transducer unit of the ultrasonic therapeutic apparatus according to the first embodiment; 
           [0060]      FIG. 53  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a second embodiment of the present invention; 
           [0061]      FIG. 54  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a third embodiment of the present invention; 
           [0062]      FIG. 55  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a fourth embodiment of the present invention; 
           [0063]      FIG. 56  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a fifth embodiment of the present invention; 
           [0064]      FIG. 57  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a sixth embodiment of the present invention; 
           [0065]      FIG. 58  is a perspective view showing a back side of the jaw of the ultrasonic therapeutic apparatus according to the sixth embodiment; 
           [0066]      FIG. 59  is a vertical cross-sectional view showing an engagement state between an electrode member of the jaw and a probe distal end portion of the ultrasonic therapeutic apparatus according to the sixth embodiment; 
           [0067]      FIG. 60  is a perspective view showing an insulation member of the jaw of the ultrasonic therapeutic apparatus according to the sixth embodiment: 
           [0068]      FIG. 61  is a perspective view showing a metallic pad of the jaw of the ultrasonic therapeutic apparatus according to the sixth embodiment; 
           [0069]      FIG. 62  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a seventh embodiment of the present invention; 
           [0070]      FIG. 63  is a perspective view showing an insulation member of the jaw of the ultrasonic therapeutic apparatus according to the seventh embodiment; 
           [0071]      FIG. 64  is a perspective view showing a metallic plate before a metallic pad of the jaw of the ultrasonic therapeutic apparatus according to the seventh embodiment is bent; 
           [0072]      FIG. 65  is a perspective view showing a first step of bending the metallic plate which is assembled to the insulation member of the jaw of ultrasonic therapeutic apparatus according to the seventh embodiment is bent; 
           [0073]      FIG. 66  is a perspective view showing a second step of bending the metallic plate which is assembled to the insulation member of the jaw of ultrasonic therapeutic apparatus according to the seventh embodiment is bent; 
           [0074]      FIG. 67  is a perspective view showing a third step of bending the metallic plate which is assembled to the insulation member of the jaw of ultrasonic therapeutic apparatus according to the seventh embodiment is bent: 
           [0075]      FIG. 68  is a perspective view showing the shape of the bent metallic pad which is assembled to the insulation member of the jaw of ultrasonic therapeutic apparatus according to the seventh embodiment is bent; 
           [0076]      FIG. 69  is a perspective view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to an eighth embodiment of the present invention; 
           [0077]      FIG. 70  is a perspective view showing the teeth of the jaw of the ultrasonic therapeutic apparatus according to the eighth embodiment; and 
           [0078]      FIG. 71  is a plan view showing the structure of a jaw of an ultrasonic therapeutic apparatus according to a ninth embodiment of the present invention. 
           [0079]      FIG. 72  is a cross-section view schematically showing a probe unit according to a first modification of the first embodiment. 
           [0080]      FIG. 73  is a cross-section view schematically showing a probe unit according to a second modification of the first embodiment. 
           [0081]      FIG. 74  is a cross-section view schematically showing a probe unit according to a third modification of the first embodiment. 
           [0082]      FIG. 75  is a cross-section view schematically showing a probe unit according to a fourth modification of the first embodiment. 
           [0083]      FIG. 76  is a cross-section view schematically showing a probe unit according to a first example of a fifth modification of the first embodiment. 
           [0084]      FIG. 77  is a cross-section view schematically showing a probe unit according to a second example of the fifth modification of the first embodiment. 
           [0085]      FIG. 78  is a cross-section view schematically showing a probe unit according to a third example of the fifth modification of the first embodiment. 
           [0086]      FIG. 79  is a cross-section view schematically showing a probe unit according to a sixth modification of the first embodiment. 
           [0087]      FIG. 80  is a cross-section view schematically showing a probe unit according to a first example of a seventh modification of the first embodiment. 
           [0088]      FIG. 81  is a cross-section view schematically showing a probe unit according to a second example of the seventh modification of the first embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0089]    A first embodiment of the present invention will now be described with reference to  FIG. 1  to  FIG. 52 .  FIG. 1  schematically shows the entire structure of a handpiece  1  of an ultrasonic therapeutic apparatus which is a surgical operating apparatus according to the first embodiment. The ultrasonic therapeutic apparatus of the present embodiment is an ultrasonic coagulation/incision apparatus. This ultrasonic coagulation/incision apparatus can perform therapeutic treatment, such as incision, resection or coagulation, of a living body tissue by making use of ultrasound, and can also perform therapeutic treatment by high-frequency waves. 
         [0090]    The handpiece  1 , as shown in  FIG. 2 , comprises four units, namely, a transducer unit  2 , a probe unit (probe section)  3 , a handle unit (operation section)  4  and a sheath unit (sheath section)  5 . These units are detachably coupled. 
         [0091]    As shown in  FIG. 4 , an ultrasonic transducer  6  for generating ultrasonic vibration by a piezoelectric oscillator, which converts an electric current to ultrasonic vibration, is built in the transducer unit  2 . An outside of the ultrasonic transducer  6  is covered with a cylindrical transducer cover  7 . As shown in  FIG. 1 , a cable  9  for supplying an electric current for generating ultrasonic vibration from a power supply device body  8  extends from a rear end of the transducer unit  2 . 
         [0092]    A proximal end portion of a horn  10 , which increases the amplitude of ultrasonic vibration, is coupled to a front end portion of the ultrasonic transducer  6 . A screw hole portion  10   a  for attaching the probe unit  3  is formed at a distal end portion of the horn  10 . 
         [0093]      FIG. 5  shows the external appearance of the entire probe unit  3 . The probe unit  3  is designed such that the entire length thereof may become an integer number of times of half-wave length of the ultrasonic vibration. The probe unit  3  has a distal end and a proximal end defining a longitudinal axis C (see  FIGS. 72-81 ), and includes a metallic rod-shaped vibration transmission member  11  extending along the longitudinal axis C. 
         [0094]    A proximal end portion of the vibration transmission member  11  is provided with a screw portion  12  which is to be engaged with the screw hole portion  10   a  of the horn  10 . The screw portion  12  is engaged with the screw hole portion  10   a  of the horn  10  of the transducer unit  2 . Thereby, the probe unit  3  and the transducer unit  2  are assembled. 
         [0095]    A probe distal end portion  3   a  is provided at a distal end portion of the vibration transmission member  11 . The probe distal end portion  3   a  is formed in a substantially J-shaped curved form. The probe distal end portion  3   a  constitutes a first electrode section which is one of a pair of bipolar electrodes. In a proximal end portion of the probe distal end portion  3   a , a screw portion  3   a   2  is provided. The distal end portion of the vibration transmission member  11  is provided with a screw hole portion  1120  which is to be engaged with the screw portion  3   a   2  (see  FIG. 72 ). 
         [0096]    Upon engagement of the screw hole portion  1120  of the vibration transmission member  11  with the screw portion  3   a   2  of the probe distal end portion  3   a , and engagement of the screw hole portion  10   a  of the horn  10  with the screw portion  12  of the vibration transmission member  11 , a first high-frequency electric path  13 , through which a high-frequency current is transmitted, is formed in the coupled body of the ultrasonic transducer  6  and the probe unit  3 . 
         [0097]    The cross-sectional area of the probe unit  3  is decreased in the axial direction at several nodes of vibration in the axial direction, so that an amplitude necessary for therapeutic treatment can be obtained at the probe distal end portion  3   a . Rubber rings  3   b  (see  FIG. 7 ), which are formed of elastic material in an annular shape, are attached to several positions of nodes of vibration along the axial direction of the probe unit  3 . The rubber rings  3   b  prevent interference between the probe unit  3  and the sheath unit  5 . 
         [0098]    A flange portion  14  is provided at the position of the node of vibration on the most proximal end side in the axial direction of the probe unit  3 . As shown in  FIG. 6 , engaging recess portions  15  each having a key groove shape are formed on the outer peripheral surface of the flange portion  14  at three positions in the circumferential direction thereof. 
         [0099]    A first modification of the probe unit  3  will be described below with reference to  FIG. 72 . 
         [0100]    As illustrated in  FIG. 72 , the vibration transmission member  11  is provided with an inner surface  1140  that defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  1140  extends in a distal direction along the longitudinal axis C to communicate the interior space with the screw hole portion  1120  of the vibration transmission member  11 . The inner surface  1140  extends in a proximal direction along the longitudinal axis C and forms a closed end of the interior space at substantially a node position B 1  of ultrasonic vibration. 
         [0101]    As an example of the communication of the interior space of the vibration transmission member  11  and the screw hole portion  1120  of the vibration transmission member  11 , the screw hole portion  1120  is provided with an internal thread portion  1122  that is arranged in a stepped manner with the inner surface  1140 . In the stepped arrangement of the screw hole portion  1120  with the inner surface  1140 , the internal thread portion  1122  is substantially coaxial with the interior space defined by the inner surface  1140  about the longitudinal axis C, while a radial dimension D 1  of the internal thread portion  1122  is greater than a radial dimension D 2  of the inner surface  1140 . 
         [0102]    In the probe distal end portion  3   a , an inner surface  3   a   4  defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  3   a   4  extends in a distal direction along the longitudinal axis C and forms a closed end of the interior space at a node position B 2  of the ultrasonic vibration. The inner surface  3   a   4  extends in a proximal direction along the longitudinal axis C through the screw portion  3   a   2  to form an open end of the interior space. 
         [0103]      FIG. 72  illustrates an example of the extension of the inner surface  3   a   4  of the probe distal end portion  3   a  through the screw portion  3   a   2  to form an open end of the interior space of the probe distal end portion  3   a . The screw portion  3   a   2  of the probe distal end portion  3   a  is provided with an external thread portion  3   a   22  to be screwed into the internal thread portion  1122  of the vibration transmission member  11 . The external thread portion  3   a   22  is substantially coaxial with the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a  about the longitudinal axis C. A radial dimension D 3  of the inner surface  3   a   4  of the probe distal end portion  3   a  is substantially the same as the radial dimension D 2  of the inner surface  1140  of the vibration transmission member  11  and less than a radial dimension D 4  of the external thread portion  3   a   22  of the probe distal end portion  3   a.    
         [0104]    Upon engagement of the screw hole portion  1120  of the vibration transmission member  11  with the screw portion  3   a   2  of the probe distal end portion  3   a , the interior space defined by the inner surface  1140  of the vibration transmission member  11  communicates with the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a  such that a closed space is formed by the inner surface  1140  and the inner surface  3   a   4 . 
         [0105]    A second modification of the probe unit  3  will be described below with reference to  FIG. 73 . 
         [0106]    As illustrated in  FIG. 73 , the vibration transmission member  11  is provided with an inner surface  1140  that defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  1140  extends in a distal direction along the longitudinal axis C to communicate the interior space with the screw hole portion  1120  of the vibration transmission member  11 . The inner surface  1140  extends in a proximal direction along the longitudinal axis C through the screw portion  12  to form an open end of the interior space. 
         [0107]    An example of the communication of the interior space of the vibration transmission member  11  and the screw hole portion  1120  of the vibration transmission member  11  is described below. The screw hole portion  1120  is provided with an internal thread portion  1122  that is arranged in a stepped manner with the inner surface  1140 . In the stepped arrangement of the screw hole portion  1120  with the inner surface  1140 , the internal thread portion  1122  is substantially coaxial with the interior space defined by the inner surface  1140  about the longitudinal axis C, while a radial dimension D 1  of the internal thread portion  1122  is greater than a radial dimension D 2  of the inner surface  1140 . 
         [0108]    In the probe distal end portion  3   a , an inner surface  3   a   4  defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  3   a   4  extends in a distal direction along the longitudinal axis C and forms a closed end of the interior space at a node position B 2  of the ultrasonic vibration. The inner surface  3   a   4  extends in a proximal direction along the longitudinal axis C through the screw portion  3   a   2  to form an open end of the interior space. 
         [0109]      FIG. 73  illustrates an example of the extension of the inner surface  3   a   4  of the probe distal end portion  3   a  through the screw portion  3   a   2  to form an open end of the interior space of the probe distal end portion  3   a . The screw portion  3   a   2  of the probe distal end portion  3   a  is provided with an external thread portion  3   a   22  to be screwed into the internal thread portion  1122  of the vibration transmission member  11 . The external thread portion  3   a   22  is substantially coaxial with the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a  about the longitudinal axis C. A radial dimension D 3  of the inner surface  3   a   4  of the probe distal end portion  3   a  is substantially the same as the radial dimension D 2  of the inner surface  1140  of the vibration transmission member  11  and less than a radial dimension D 4  of the external thread portion  3   a   22  of the probe distal end portion  3   a.    
         [0110]      FIG. 73  illustrates an example of the extension of the inner surface  1140  of the vibration transmission member  11  through the screw portion  12  to form the open end of the interior space of the vibration transmission member  11 . The screw portion  12  of the vibration transmission member  11  is provided with an external thread portion  121  to be screwed into an internal thread portion  10   a   2  of the screw hole portion  10   a  of the horn  10 . The external thread portion  121  is substantially coaxial with the interior space defined by the inner surface  1140  of the vibration transmission member  11  about the longitudinal axis C. The radial dimension D 2  of the inner surface  1140  of the vibration transmission member  11  is less than a radial dimension D 5  of the internal thread portion  10   a   2  of the screw portion  12 . 
         [0111]    Upon engagement of the screw hole portion  1120  of the vibration transmission member  11  with the screw portion  3   a   2  of the probe distal end portion  3   a , the interior space defined by the inner surface  1140  of the vibration transmission member  11  communicates with the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a  such that a space is formed by the inner surface  1140  and the inner surface  3   a   4 . 
         [0112]    A third modification of the probe unit  3  will be described below with reference to  FIG. 74 . 
         [0113]    In the fourth modification, the probe distal end portion  3   a  and the vibration transmission member  11  are formed as a single integral piece. 
         [0114]    As illustrated in  FIG. 74 , the vibration transmission member  11  is provided with an inner surface  1140  that defines an interior space extending along the longitudinal axis C of the probe unit  3  and the probe distal end portion  3   a  is provided with an inner surface  3   a   4  that defines an interior space extending along the longitudinal axis C of the probe unit  3 . 
         [0115]    The inner surface  3   a   4  of the probe distal end portion  3   a  extends in a distal direction along the longitudinal axis C to form a closed end. The inner surface  3   a   4  of the probe distal end portion  3   a  extends in a proximal direction along the longitudinal axis C to meet the inner surface  1140  of the vibration transmission member  11 . The inner surface  1140  of the vibration transmission member  11  extends in a proximal direction along the longitudinal axis C through the screw portion  12  to form an open end of the interior space. 
         [0116]      FIG. 74  illustrates an example of the extension of the inner surface  1140  of the vibration transmission member  11  through the screw portion  12  to form the open end of the interior space of the vibration transmission member  11 . The screw portion  12  of the vibration transmission member  11  is provided with an external thread portion  121  to be screwed into an internal thread portion  10   a   2  of the screw hole portion  10   a  of the horn  10 . The external thread portion  121  is substantially coaxial with the interior space defined by the inner surface  1140  of the vibration transmission member  11  about the longitudinal axis C. The radial dimension D 1  of the inner surface  1140  of the vibration transmission member  11  is less than a radial dimension D 2  of the external thread portion  121  of the screw portion  12 . 
         [0117]    Compatible with the second and third modifications of the probe unit  3 , the horn  10  can be provided with a passage portion about the longitudinal axis C from the screw hole portion  10   a  to the proximal end of the horn  10 , and the ultrasonic transducer  6  can be provided with a passage portion about the longitudinal axis C. The passage portion of the horn  10  and the passage portion of the ultrasonic transducer  6  can be coaxial with the interior space defined by the inner surface  1140  of the vibration transmission member  11  and the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a.    
         [0118]    A fourth modification of the probe unit  3  will be described below with reference to  FIG. 75 . 
         [0119]    As illustrated in  FIG. 75 , the vibration transmission member  11  is provided with an inner surface  1140  that defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  1140  extends in a distal direction along the longitudinal axis C to communicate the interior space with the screw hole portion  1120  of the vibration transmission member  11 . The inner surface  1140  extends in a proximal direction along the longitudinal axis C and forms a closed end of the interior space in the vicinity of the screw portion  12 . 
         [0120]    In the vibration transmission member  11 , the screw hole portion  1120  is provided with an internal thread portion  1122  that is arranged in a stepped manner with the inner surface  1140  of the vibration transmission member  11 . In the stepped arrangement of the screw hole portion  1120  with the inner surface  1140 , the internal thread portion  1122  is substantially coaxial with the interior space defined by the inner surface  1140  about the longitudinal axis C, while a radial dimension D 1  of the internal thread portion  1122  is greater than a radial dimension D 2  of the inner surface  1140 . 
         [0121]    In the probe distal end portion  3   a , an inner surface  3   a   4  defines an interior space extending along the longitudinal axis C of the probe unit  3 . The inner surface  3   a   4  extends in a distal direction along the longitudinal axis C and forms a closed end of the interior space at a node position B 2  of the ultrasonic vibration. The inner surface  3   a   4  extends in a proximal direction along the longitudinal axis C through the screw portion  3   a   2  to form an open end of the interior space. 
         [0122]    In the probe distal end portion  3   a , the screw portion  3   a   2  of the probe distal end portion  3   a  is provided with an external thread portion  3   a   22  to be screwed into the internal thread portion  1122  of the vibration transmission member  11 . The external thread portion  3   a   22  is substantially coaxial with the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a  about the longitudinal axis C. A radial dimension D 3  of the inner surface  3   a   4  of the probe distal end portion  3   a  is substantially the same as the radial dimension D 1  of the inner surface  1140  of the vibration transmission member  11  and less than a radial dimension D 4  of the external thread portion  3   a   22  of the probe distal end portion  3   a.    
         [0123]    Further, a through port  116  connecting the inner surface  1140  of the vibration transmission member  11  and an external surface of the vibration transmission member  11  is provided at a node position B 1  of the ultrasonic vibration. The node position B 1  is proximal to the node position B 2  and positioned along the longitudinal axis C in the vibration transmission member  11  to be closer to the screw portion  12  than to the screw hole portion  1120 . 
         [0124]    In the first to fourth modifications of the probe unit  3  described above, various material and combination of materials are contemplated. In a first example, both the probe distal end portion  3   a  and the vibration transmission member  11  can be formed of a titanium alloy. In a second example, both the probe distal end portion  3   a  and the vibration transmission member  11  can be formed of stainless steel. In a third example, the probe distal end portion  3   a  can be formed of a titanium alloy and the vibration transmission member  11  can be formed of stainless steel. In the third example, for a probe unit  3  that is approximately 430 mm in length along the longitudinal axis C and approximately 15 grams in weight, the vibration transmission member  11  formed of stainless steel can be approximately 9 grams in weight and a radial thickness of the vibration transmission member  11  from the outer surface of the vibration transmission member  11  to the inner surface  1140  of the vibration transmission member  11  is approximately 0.012 inches and within a range of 0.010 inches and 0.015 inches. 
         [0125]    A conventional vibration transmission member can be constructed as a solid titanium alloy rod. In contrast, in the second and third example, the vibration transmission member  11  is constructed of stainless steel. In selecting stainless steel as a replacement material, it is contemplated that the resulting vibration transmission member  11  has a same or substantially same weight as the conventional vibration transmission member, the resulting vibration transmission member  11  has a same or substantially same strength to sustain mechanical loads as the conventional vibration transmission member, and the resulting vibration transmission member  11  has a same or substantially same outer diameter as the conventional vibration transmission member. 
         [0126]    In the case of keeping the weight of the vibration transmission member  11  the same as the conventional vibration transmission member, as well keeping the outer diameter of the vibration transmission member  11  the same as the outer diameter of the conventional vibration transmission member, the following formula can be used to calculate the radial thickness (Wall Thickness tube ) of the vibration transmission member  11 : 
         [0000]      Wall Thickness tube   =D (1−(1−ρ 1 /ρ 2 ) 0.5 ),
       where:   D is the outer diameter of the conventional vibration transmission member,   ρ 1  is the density of the titanium alloy of the conventional vibration transmission member, and   ρ 2  is the density of the stainless steel selected for the vibration transmission member.       
 
         [0131]    Selection of other material or materials for forming the probe distal end portion  3   a  and the vibration transmission member  11  is contemplated. Factors that can be considered in the selection of material or materials for forming the probe distal end portion  3   a  and the vibration transmission member  11  will be described below. The material or materials can be selected based on the ultrasonic energy transmission requirements of the probe unit  3 . Further, the material or materials can be selected based on the electric conductivity requirements of the probe unit  3 . 
         [0132]    As a variation of the first to fourth modifications of the probe unit  3 , it is also contemplated that the vibration transmission member  11  can be formed from a plurality of segments connected in series by, for example, welding, to result in a structure substantially the same as the vibration transmission member  11  described above in the first to fourth modifications. 
         [0133]    A fifth modification of the probe unit  3  will be described below with reference to  FIG. 76 . 
         [0134]    The fifth modification of the probe unit  3  incorporates a heat pipe  200 . The heat pipe  200  can include a tube that is partially filled with a working fluid and then sealed. The sealed tube can be composed of a heat conduction material such as copper or silver that is stable enough to be configured to allow the sealed tube to hold a vacuum. The working fluid mass is chosen so that the heat pipe  200  contains both vapor and liquid over the operating temperature range of the probe unit  3 . Examples of the working fluid include water or an alcohol. 
         [0135]    Heat energy which is conducted into the distal end portion of the heat pipe  200  causes the internal evaporation of the working fluid of heat pipe  200  and its subsequent recondensation in the cooler regions of heat pipe  200  at positions proximal to the distal end portion of the heat pipe  200 . 
         [0136]    Heat pipe  200  can further include an internal wick structure to return the recondensed working fluid to the distal end portion of the heat pipe  200 . An example of the internal wick structure is sintered metal powder lining the inner surface of the sealed tube along the length of the sealed tube. The recondensed working fluid in the heat pipe  200  is drawn along the length of the tube by capillary action of the porous sintered metal lining the inner surface of the enclosed tube toward the distal end portion of the sealed tube. Another example of the internal wick structure is grooves formed on the inner surface of the sealed tube along the length of the sealed tube. The recondensed working fluid in the heat pipe  200  is drawn along the length of the grooves by capillary action toward the distal end portion of the sealed tube. Another example of the internal wick structure is a metal mesh wick arranged along the inner surface of the enclosed tube. The recondensed working fluid in the heat pipe  200  is drawn along the length of the tube by the capillary action of the metal mesh wick toward the distal end portion of the sealed tube. 
         [0137]    A first example of the probe unit  3  according to the fifth modification will be described below with reference to  FIG. 76 . 
         [0138]    In the first example, the heat pipe  200  is provided within the probe unit  3  described in the first modification. Specifically, the heat pipe  200  is arranged in the closed space formed by the interior space defined by the inner surface  1140  of the vibration transmission member  11  and the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a.    
         [0139]    In the first example, the distal end portion of the heat pipe  200  can be attached to the inner surface  3   a   4  of the probe distal end portion  3   a  at the node position B 2  and the proximal end portion of the heat pipe  200  can be attached to the inner surface of the vibration transmission member  11  at the node position B 1 . 
         [0140]    At node positions B 1 , B 2  of the ultrasonic vibration, the stress in the directions perpendicular to the longitudinal axis C is maximized, but the displacement due to ultrasonic vibration becomes zero. Therefore, by attaching the distal end portion and the proximal end portion of the heat pipe  200  to the inner surface  1140  at node position B 1  and the inner surface  3   a   4  at node position B 2 , the heat pipe  200  is not easily influenced by the ultrasonic vibration. As a result, the heat pipe  200  is prevented from being damaged. 
         [0141]    A second example of the probe unit  3  according to the fifth modification will be described below with reference to  FIG. 77 . 
         [0142]    In the second example, the heat pipe  200  is provided within the probe unit  3  described in the second modification. Specifically, the heat pipe  200  is arranged in the space formed by the interior space defined by the inner surface of the vibration transmission member  11  and the interior space defined by the inner surface  200  of the probe distal end portion  3   a.    
         [0143]    The heat pipe  200  can extend proximally along the longitudinal axis C past the open end of the interior space of the vibration transmission member  11  and into one or both of the passage portion of the horn  10  and the passage portion of the ultrasonic transducer  6 . 
         [0144]    In the second example, the heat pipe  200  can be attached at a distal end portion along the longitudinal axis C to the inner surface  3   a   4  of the probe distal end portion  3   a  at the node position B 2  and can be attached at a proximal end portion along the longitudinal axis C to the inner surface of the vibration transmission member  11  at another node position. 
         [0145]    A third example of the probe unit according to the fifth modification will be described below with reference to  FIG. 78 . 
         [0146]    In the third example, the heat pipe  200  is provided within the probe unit  3  described in the third modification. Specifically, the heat pipe  200  is arranged in the space formed by the interior space defined by the inner surface  1140  of the vibration transmission member  11  and the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a.    
         [0147]    The heat pipe  200  can extend proximally along the longitudinal axis C past the open end of the interior space of the vibration transmission member  11  and into one or both of the passage portion of the horn  10  and the passage portion of the ultrasonic transducer  6 . 
         [0148]    In the third example, a distal end portion of the heat pipe  200  can be attached to the inner surface  3   a   4  of the probe distal end portion  3   a  at the node position B 2  and a proximal end portion of the heat pipe  200  can be attached to the inner surface  1140  of the vibration transmission  11  at another node position. 
         [0149]    A sixth modification of the probe unit  3  will be described below with reference to  FIG. 79 . 
         [0150]    The sixth modification of the probe unit  3  incorporates a thermal dissipating core material  300  such as graphite. Other thermal conducting material such as copper, silver and gold can be selected as the thermal dissipating core material  300 . 
         [0151]    In an example of probe unit  3  according to the sixth modification, the thermal dissipating core material  300  is provided within the probe unit  3  described in the first modification. 
         [0152]    The thermal dissipating core material  300  can be arranged in the closed space formed by the interior space defined by the inner surface  1140  of the vibration transmission member  11  and the interior space defined by the inner surface  3   a   4  of the probe distal end portion  3   a . Specifically, the thermal dissipating core material  300  can be formed in a rod shape that conforms to the inner surface  1140  of the vibration transmission member  11  and the inner surface  3   a   4  of the probe distal end portion  3   a.    
         [0153]    Heat energy which is conducted into the distal end portion of the thermal dissipating core material  300  is dissipated by the thermal dissipating core material  300  at a portion proximal to the distal end portion of the thermal dissipating core material  300 . 
         [0154]    A seventh modification of the probe unit  3  will be described below with reference to  FIG. 80 . 
         [0155]    In the seventh modification, a closed loop coolant circulation system  400  is provided. The closed loop coolant circulation system  400  can include a coolant tubing  420 , a coolant pump  440 , and a heat exchanger  460 . 
         [0156]    The coolant tubing  420  includes an input tubing segment  422 , an output tubing segment  424 , and a heat exchange tubing segment  426 . The input tubing segment  422  is arranged within the interior space of the vibration transmission member  11  and the interior space of the probe distal end portion  3   a . The input tubing segment  422  passes an inflow of coolant through the interior space of the vibration transmission member  11  and into the interior space of the probe distal end portion  3   a . The input tubing segment  422  is in thermal contact with the probe distal end portion  3   a  to pick up heat from the probe distal end portion  3   a . The output tubing segment  424  is arranged within the interior space of the probe distal end portion  3   a  and the interior space of the vibration transmission member  11 . The output tubing segment  424  passes an outflow of heated coolant through the interior space of the probe distal end portion  3   a  and through the interior space of the vibration transmission member  11 . The coolant pump  440  is connected at an input end to the output tubing segment  424  and at an output end to the heat exchange tubing segment  426 . The coolant pump  440  pumps the heated coolant from the output tubing segment  424  to the heat exchange tubing segment  426 . The heat exchange tubing segment  426  connects the coolant pump  440  to the heat exchanger  460  in the form of coolant flow. As the coolant pump  440  operates, it causes the coolant to flow through heat exchanger  460 , along input tubing segment  422 , through the probe distal end portion  3   a , back through output tubing segment  424 , and finally back to the coolant pump  440  for another cycle. 
         [0157]    The coolant pump  440  may be powered electrically, mechanically or pneumatically. The heat exchanger  460  can be a liquid-to-air heat exchanger. In the liquid-to-air heat exchanger, coolant is flowed inside of the heat exchanger  460  and air on the outside of heat exchanger  460  carries the heat away. The air on the outside of the heat exchanger  460  can be naturally convected or forced across heat exchanger  460 . Examples of the heat exchanger  460  include a radiator or a combination of a fan and the radiator. 
         [0158]    A first example of the probe unit  3  according to the seventh modification will be described below with reference to  FIG. 80 . 
         [0159]    In the first example, the closed loop coolant circulation system  400  is provided within the probe unit  3  described in the second modification or the third modification. 
         [0160]    In the first example, the input tubing segment  422  is arranged to be in thermal contact with the probe distal end portion  3   a . Further, the input tubing segment  422  and the output tubing segment  424  extend proximally through the open end of the interior space of the vibration transmission member  11  and the heat exchange tubing segment  426 , the coolant pump  440  and the heat exchanger  460  are arranged on the exterior of the probe unit  3 . 
         [0161]    A second example of the probe unit  3  according to a seventh modification will be described below with reference to  FIG. 81 . In the second example, the closed loop coolant circulation system  400  is provided within the probe unit  3  described in the fourth modification. 
         [0162]    In the second example, the input tubing segment  422  is arranged to be in thermal contact with the probe distal end portion  3   a . Further the input tubing segment  422  and the output tubing segment  424  extend proximally in the interior space of the vibration transmission member  11  and through the through port  116  to the exterior of the probe unit  3 . Specifically, the input tubing segment  422  and the output tubing segment  424  are bent from a direction substantially parallel to the longitudinal axis C to a direction substantially perpendicular to the longitudinal axis C at the through port  116 . As discussed above, the through port  116  is provided at the node position B 1  of the ultrasonic vibration. At the node position B 1 , stress in the directions perpendicular to the longitudinal axis C is maximized, but displacement due to ultrasonic vibration becomes zero. Therefore, when the input tubing segment  422  and the output tubing segment  424  are bent at the node position B 1 , the bent portion of the input tubing segment  422  and the bent portion of the output tubing segment  424  are not easily influenced by the ultrasonic vibration. Therefore, the input tubing segment  422  and the output tubing segment  424  are effectively prevented from being damaged by the ultrasonic vibration. 
         [0163]      FIG. 8A  shows a distal end portion of the sheath unit  5 , and  FIG. 9A  shows a proximal end portion of the sheath unit  5 . As shown in  FIG. 8A , the sheath unit  5  includes a sheath body  16 , which is formed of a cylindrical body, and a jaw  17  which is provided at a distal end of the sheath body  16 . The sheath body  16  includes a metallic sheath  18  which is an outer cylinder, and a metallic driving pipe  19  which is an inner cylinder. The driving pipe  19  is axially movably inserted in the sheath  18 . 
         [0164]    As shown in  FIG. 8A , the outer peripheral surface of the sheath  18  is covered with an outer coating  18   a  which is formed of an insulating material such as a resin. An insulation tube  24 , which is formed of an insulating material, is provided on the inner peripheral side of the driving pipe  19 . 
         [0165]    As shown in  FIGS. 10 to 12 , a pair of right and left projection portions  25  are provided at a distal end portion of the sheath  18  so as to project in a forward direction of the sheath  18 . A proximal end portion of the jaw  17  is rotatably attached to the projection portions  25  via a support pin  27 . When the probe unit  3  and the sheath unit  5  are assembled, the jaw  17  is positioned to be opposed to the probe distal end portion  3   a  of the probe unit  3 . 
         [0166]    As shown in  FIG. 8B , the jaw  17  is formed in a substantially J-shaped curved form, which corresponds to the curved shape of the probe distal end portion  3   a , in accordance with the curved shape of the probe distal end portion  3   a  of the probe unit  3 . The jaw  17  is configured to be rotated about the support pin  27  by the advancing/retreating movement of the driving pipe  19  in the axial direction. A therapeutic section  1 A of the handpiece  1  is constituted by the jaw  17  and the probe distal end portion  3   a.    
         [0167]    The jaw  17  includes a metallic jaw body  201  (see  FIG. 14 ) which is an electrically conductive member, and a hold member  202  which is attached to the jaw body  201 . The hold member  202  is composed of an electrode member  203  (see  FIG. 15 ) for high-frequency therapeutic treatment, and an insulation member  204  (see  FIG. 16 ) for ultrasonic therapeutic treatment. The electrode member  203  constitutes a second electrode section which is the other electrode of the bipolar electrodes. 
         [0168]    As shown in  FIGS. 17 and 18 , a groove portion  205 , which is formed in accordance with the curved shape of the probe distal end portion  3   a , is formed on the lower surface of the electrode member  203 . An engaging surface  206 , which is to be engaged with the probe distal end portion  3   a , is formed by the groove portion  205 . A groove width W of the groove portion  205  is set in consideration of the diameter dimension of the probe distal end portion  3   a . Specifically, the groove width W is set to be greater than the diameter dimension of the probe distal end portion  3   a  by a predetermined ratio, thereby preventing contact between the engaging surface  206  of the electrode member  203  and the probe distal end portion  3   a.    
         [0169]    Inclined surfaces  205   a , which are configured to gradually increase the groove width toward a lower-side opening surface, as shown in  FIG. 18 , are formed on both side wall surfaces of the groove portion  205 . In addition, as shown in  FIG. 19 , tooth portions  203   b  for preventing a slip are formed on both side walls  203   a  of the groove portion  205  on the lower-side opening surface side. The tooth portions  203   b  form a slip-preventing section for preventing a slip of a clamped object between the probe distal end portion  3   a  and the jaw  17  when the jaw  17  and probe distal end portion  3   a  are engaged. A wall thickness T of the electrode member  203  is properly determined in consideration of the rigidity and coagulation performance. 
         [0170]    Further, in the electrode member  203 , a notch portion  205   b  is formed at a bottom portion of the groove portion  205 . The notch portion  205   b  is formed in accordance with the curved shape of the probe distal end portion  3   a . A pad member  207 , which is formed of an insulating material, for instance, a resin material such as polytetrafluoroethylene, is disposed in the notch portion  205   b . As shown in  FIG. 18 , the pad member  207  is a probe contact member which is in contact with the probe distal end portion  3   a . The probe distal end portion  3   a  comes in contact with the pad member  207 , thus securing a clearance between the second electrode section of the electrode member  203  and the probe distal end portion  3   a.    
         [0171]    In addition, the jaw  17  has a block-shaped distal end chip  208  at a distal end portion of the engaging surface  206  for engagement with the probe distal end portion  3   a . The distal end chip  208  is formed of an insulating material, for instance, a resin material such as polytetrafluoroethylene. When the jaw  17  and probe distal end portion  3   a  are engaged, a positional displacement relative to the probe distal end portion  3   a  is tolerated by the distal end chip  208 . 
         [0172]    As shown in  FIG. 16 , in the insulation member  204 , the distal end chip  208  is coupled to the distal end portion of the pad member  207 . In the insulation member  204 , the pad member  207  and the distal end chip  208  are provided as one body. 
         [0173]    The electrode member  203  and insulation member  204  are integrally assembled to form the hold member  202 . A hook-shaped engaging portion  209  is formed at a rear end portion of the insulation member  204 . In addition, a distal end chip engaging portion  203   c , which engages the distal end chip  208 , is formed at the distal end portion of the electrode member  203 . When the electrode member  203  and the insulation member  204  are assembled, the distal end chip  208  is engaged with the distal end chip engaging portion  203   c , and also the engaging portion  209  at the rear end portion of the insulation member  204  is engaged with the rear end portion of the electrode member  203  in the state in which the pad member  207  is inserted in the notch portion  205   b  of the groove portion  205  of the electrode member  203 . 
         [0174]    A projection portion  210  for attachment is provided on that side of the hold member  202 , which is opposed to the engaging surface  206  for engagement with the probe distal end portion  3   a . A screw insertion hole  211  is formed in the projection portion  210 . 
         [0175]    A hold member engaging portion  212 , which engages the projection portion  210  of the hold member  202 , is provided on a distal end side of the jaw body  201 . The hold member  202  is engaged with the hold member engaging portion  212 . Further, a screw hole  213  is formed in side wall portions of the hold member engaging portion  212 . As shown in  FIG. 18 , when the hold member engaging portion  212  of the jaw body  201  and the projection portion  210  of the hold member  202  are engaged, a fixing screw  214 , which is engaged in the screw hole  213  of the jaw body  201 , is inserted in the screw insertion hole  211  of the hold member  202 . In this state, the fixing screw  214  is fastened in the screw hole  213 , and thereby the hold member  202  is attached to the jaw body  201 . The electrode member  203  of the hold member  202  and the jaw body  201  are electrically connected via the fixing screw  214 . 
         [0176]    A proximal end portion of the jaw body  201  has two-forked arm portions  215   a  and  215   b . The respective arm portions  215   a  and  215   b  have extension portions  215   a   1  and  215   b   1 , which extend obliquely downward from a position of a center line of the jaw body  201 . The extension portions  215   a   1  and  215   b   1  are rotatably attached by the support pin  27  to the right and left projection portions  25  at the distal end portion of the sheath  18 . 
         [0177]    A coupling pin insertion hole  216  is formed in a proximal portion of each of the two arm portions  215   a  and  215   b . A coupling pin  217  for coupling the jaw body  201  and the driving pipe  19  is inserted in the coupling pin insertion holes  216 . The jaw body  201  and the driving pipe  19  are electrically connected via the coupling pin  217 . 
         [0178]    Thereby, the driving force of the driving pipe  19  is transmitted to the jaw  17  via the coupling pin  217  by the advancing/retreating in the axial direction of the driving pipe  19 . Accordingly, the jaw  17  is rotated about the support pin  27 . In this case, when the driving pipe  19  is pulled rearward, the jaw  17  is rotated about the support pin  27  and driven (to an open position) in a direction away from the probe distal end portion  3   a . Conversely, when the driving pipe  19  is pushed forward, the jaw  17  is rotated about the support pin  27  and driven (to a closed position) in a direction toward the probe distal end portion  3   a . A living body tissue is held between the jaw  17  and the probe distal end portion  3   a  of the probe unit  3  when the jaw  17  is rotated to the closed position. 
         [0179]    The therapeutic section  1 A of the handpiece  1  is constituted by the jaw  17  and the probe distal end portion  3   a  of the probe unit  3 . The therapeutic section  1 A is configured to selectively perform a plurality of therapeutic functions, for example, two therapeutic functions (a first therapeutic function and a second therapeutic function) in this embodiment. For instance, the first therapeutic function is set to be a function of simultaneously outputting an ultrasonic therapeutic output and a high-frequency therapeutic output. The second therapeutic function is set to be a function of outputting only the high-frequency therapeutic output. 
         [0180]    The first therapeutic function and second therapeutic function of the therapeutic section  1 A are not limited to the above-described configuration. For example, the first therapeutic function may be set to be a function of outputting an ultrasonic therapeutic output in a maximum output state, and the second therapeutic function may be set to be a function of outputting the ultrasonic therapeutic output in a preset arbitrary output state which is lower than the maximum output state. 
         [0181]    As shown in  FIGS. 17 and 19 , the jaw  17  has, at a distal end portion of the groove portion  205 , a distal-end-side groove width varying section  205   t   1  which has such a tapering shape that the groove width of the groove portion  205  gradually increases toward the distal end. In addition, the jaw  17  has, at a proximal end portion of the groove portion  205 , a proximal-end-side groove width varying section  205   t   2  which has such a tapering shape that the groove width of the groove portion  205  gradually increases toward the proximal end. In the distal-end-side groove width varying section  205   t   1  and proximal-end-side groove width varying section  205   t   2 , a positional displacement in assembly between the probe distal end portion  3   a  and the electrode member  203  of the jaw  17  can be tolerated in a case where the assembly position of the electrode member  203  of the jaw  17  is slightly displaced, relative to the probe distal end portion  3   a , in the axial direction of the sheath unit  5  when the probe unit  3  and the sheath unit  5  are assembled. 
         [0182]      FIG. 21  shows the driving pipe  19 . The driving pipe  19  includes a tubular body section  221  and an operating section  222 . The body section  221  is inserted in the sheath  18  so as to be slidable in the axial direction of the sheath  18 . The operating section  222  is disposed on the distal end side of the body section  221 , and includes a connection section  223  which is connected to the jaw  17 . 
         [0183]    As shown in  FIG. 22 , the peripheral wall of a tubular distal end portion of the body section  221  includes a crescent-shaped arcuate cross-sectional portion  224 , which is formed by leaving a substantially crescent-shaped arcuate cross-sectional portion over a predetermined length in the axial direction, and cutting out the other portion. As shown in  FIG. 23 , the arcuate cross-sectional portion  224  includes a taper portion  225  with a tapered distal end portion, which is gradually tapered toward the distal end side. As shown in  FIG. 22  and  FIG. 25 , a U-shaped portion  226  having a U-shaped cross section is formed at a distal end of the taper portion  225 . The operating section  222  is constituted by the U-shaped portion  226 . 
         [0184]    As shown in  FIG. 22 , the U-shaped portion  226  has two side surfaces  226   a  and  226   b , which are opposed to each other, and a connecting surface  226   c  which connects the two side surfaces  226   a  and  226   b . The connection section  223  is formed in each of the two side surfaces  226   a  and  226   b  of the U-shaped portion  226 . 
         [0185]    The operating section  222  has a slit  227  extending in the axial direction of the sheath  18  in a distal end portion of the connecting surface  226   c . As shown in  FIG. 23 , the slit  227  has a terminal end portion  227   a  which is located at a position corresponding to a proximal end portion of the taper portion  225 . 
         [0186]    As shown in  FIG. 8A , the insulation tube  24  includes a projection portion  228  which projects forward of the body section  221  of the driving pipe  19 . The projection portion  228  extends up to a rear end position of the U-shaped portion  226 . 
         [0187]    Further, a proximal end portion of the insulation tube  24  extends to a proximal end side of the sheath body  16 . The driving pipe  19  and probe unit  3  are electrically insulated by the insulation tube  24 . 
         [0188]      FIG. 9  shows a proximal end portion of the sheath body  16 . The proximal end portion of the sheath  18  includes a flare portion  229  which has a greater inside diameter than the other portion. A proximal end portion of the driving pipe  19  extends more rearward than the flare portion  229  of the sheath  18 . 
         [0189]    Seal means  230  for effecting sealing between the sheath  18  and the driving pipe  19  is provided between the flare portion  229  and the driving pipe  19 . The seal means  230  includes two backup rings  231  and  232  and one 0 ring  233 . The two backup rings  231  and  232  are disposed between the flare portion  229  and the driving pipe  19  in the state in which the two backup rings  231  and  232  are paired in a back-and-forth direction along the axis of the sheath  18 . The O ring  233  is provided between the backup rings  231  and  232  so as to be movable in the axial direction of the sheath  18 . 
         [0190]    In addition, the proximal end portion of the sheath body  16  is provided with an attachment/detachment mechanism section  31  for attachment/detachment to/from the handle unit  4 . The attachment/detachment mechanism section  31  includes a cylindrical large-diameter handle member  32  which is formed of a resin material, a guide cylindrical body (first tubular member)  33  which is formed of a metallic cylindrical body, and a cylindrical connection tube body (second tubular member)  34  which is formed of a resin material. 
         [0191]    The guide cylindrical body  33  includes a tubular body  33   a  which is fitted on the flare portion  229  of the proximal end portion of the sheath  18  and extends rearward. A distal end portion of the tubular body  33   a  is provided with a large-diameter  33   b  which has a greater outside diameter than the other portion thereof. The handle member  32  is fitted on the large-diameter portion  33   b . A connection flange portion  33   c , which projects outward, is formed on an outer peripheral surface of a rear end portion of the guide cylindrical body  33 . 
         [0192]    As shown in  FIG. 27 , an outer peripheral wall portion of the tubular  33   a  has an elongated slit  234  extending in the axial direction of the sheath  18 . In addition, on the rear end portion side of the guide cylindrical body  33 , a distal end portion of the connection tube body  34  is inserted so as to be slidable in the axial direction of the sheath  18 . A proximal end portion of the driving pipe  19  is fitted and inserted inside the inner peripheral surface of the distal end portion of the connection tube body  34 . 
         [0193]    As shown in  FIG. 28 , a threaded pin (projection body)  235  is fixed to a proximal end portion of the driving pipe  19 . As shown in  FIG. 26 , the threaded pin  235  includes a male screw member  236 . A threaded hole portion  237 , which is engaged with a male screw portion  236  a of the threaded pin  235 , is formed in the connection tube body  34 . 
         [0194]    A large-diameter portion  236   b , which has a greater diameter than the male screw portion  236   a , is formed on a head portion of the screw member  236 . The large-diameter portion  236   b  of the threaded pin  235  is an engaging portion which is engaged in the slit  234  of the guide cylindrical body  33 . 
         [0195]    A small-diameter portion  238 , which has a smaller diameter than the male screw portion  236   a , is provided on the threaded pin  235  so as to project on a side opposite to the head portion of the screw member  236 . The small-diameter portion  238  is inserted and fitted in a fixing hole  239  which is formed in a proximal end portion of the driving pipe  19 . Thereby, the male screw portion  236   a  of the threaded pin  235  is engaged in and passed through the screw hole portion  237  of the connection tube body  34 , and a coupling body  240 , in which the driving pipe  19  and the connection tubular body  34  are coupled, is formed. Further, the large-diameter portion  236   b  of the threaded pin  235  is engaged with the slit  234  of the guide cylindrical body  33 , and thereby the coupling body  240  is coupled to the guide cylindrical body  33  so as to be movable as one body along the slit  234  in the axial direction of the sheath  18 . 
         [0196]    A fixing section  35  of the guide cylindrical body  33  is formed by an engaging section between the handle member  32  and the large-diameter portion  33   b  of the guide cylindrical body  33 . Further, in the handle member  32 , an attachment/detachment section  36  for attachment/detachment to/from the handle unit  4  is disposed on the rear side of the fixing section  35 . 
         [0197]      FIG. 29  to  FIG. 32  show the structure of the attachment/detachment part between the handle member  32  and the handle unit  4 . As shown in  FIGS. 30 to 32 , the attachment/detachment section  36  of the handle member  32  has a guide groove  41  with an inclined surface, and an engaging recess portion  42 . The guide groove  41  is provided to extend in a circumferential direction on the outer peripheral surface of the proximal end portion of the handle member  32 . In addition, the guide groove  41  has a tapered inclined surface with an outside diameter decreasing toward the rear end portion side of the handle member  32 . 
         [0198]    As shown in  FIG. 33 , the engaging recess portion  42  is formed at one end portion of the guide groove  41 . The engaging recess portion  42  is formed of a recess portion having a smaller diameter than the inclined surface of the guide groove  41 . The engaging recess portion  42  is configured such that the engaging lever  43  (to be described later) on the handle unit  4  side is disengageably engaged in the engaging recess portion  42 .  FIGS. 31 and 32  show the state in which the engaging lever  43  is engaged in the engaging recess portion  42 , and  FIGS. 29 and 30  show the disengaged state in which the engaging lever  43  is pulled out of the engaging recess portion  42 . 
         [0199]    As shown in  FIGS. 34 and 35 , a proximal end portion of the connection tube body  34  has two guide grooves  44  which are used at a time of attachment/detachment to/from the handle unit  4  side. The guide grooves  44  are configured such that two engaging pins  45  (to be described later) on the handle unit  4  side are disengageably engaged in the guide grooves  44 , respectively. An engaging groove  44   a , which restricts movement of the engaging pin  45  in the axial direction of the sheath body  16 , is formed at a terminal end portion of the guide groove  44 . 
         [0200]    As shown in  FIG. 9B , the connection flange portion  33   c  of the guide cylindrical body  33  has a non-circular engaging portion  46 . The engaging portion  46  has three cut-out flat-surface portions  46   a  at a plurality of locations on the circular outer peripheral surface of the connection flange portion  33   c , for example, at three locations in this embodiment. Corner portions  46   b , each having a greater diameter than the flat-surface portion  46   a , are formed at connection parts between the three flat-surface portions  46 . Thereby, the engaging portion  46  with a substantially triangular cross section is formed on the connection flange portion  33   c . It is not necessary that the non-circular engaging portion  46  have a substantially triangular shape. The non-circular engaging portion  46  may have any other non-circular shape, for instance, a polygon such as a rectangle or a pentagon. 
         [0201]    As shown in  FIG. 3 , the handle unit  4  mainly includes a stationary handle  47 , a hold cylinder  48 , a movable handle  49  and a rotational operation knob  50 . The hold cylinder  48  is provided on the upper part of the stationary handle  47 . A switch hold section  51  is provided between the stationary handle  47  and the hold cylinder  48 . As shown in  FIG. 36 , the switch hold section  51  includes a switch attachment section  52  which is fixed to a lower end portion of the hold cylinder  48 , and a cover member  53  which is fixed to an upper end portion of the stationary handle  47 . 
         [0202]    As shown in  FIG. 37 , the switch attachment section  52  has a switch attachment surface  52   a  on a front side thereof, to which a plurality of hand switches, for example, two hand switches (first switch  54  and second switch  55 ) in the present embodiment, are attached. The first switch  54  and second switch  55  are switches for selecting therapeutic functions of the therapeutic section  1 A of the handpiece  1 . 
         [0203]    In the switch attachment section  52 , the first switch  54  and second switch  55  are arranged in the up-and-down direction. The first switch  54  is disposed on an upper side of the switch attachment surface  52   a , and is set to be a switch which selects a first therapeutic function that is frequently used among the plural therapeutic functions. The second switch  55  is disposed on a lower side of the switch attachment surface  52   a , and is set to be a switch which selects another second therapeutic function of the plural therapeutic functions. 
         [0204]    As shown in  FIG. 2 , the movable handle  49  has a substantially U-shaped arm section  56  at an upper part thereof. The U-shaped arm section  56  includes two arms  56   a  and  56   b . The movable handle  49  is assembled to the hold cylinder  48  in the state in which the hold cylinder  48  is inserted between the two arms  56   a  and  56   b.    
         [0205]    Each of the arms  56   a  and  56   b  has a support pin  57  and an operation pin  58 . As shown in  FIG. 36 , a pin receiving hole portion  59  and a window portion  60  are formed in each of both side portions of the hold cylinder  48 . The support pin  57  of each arm  56   a ,  56   b  is inserted in the pin receiving hole portion  59  of the hold cylinder  48 . Thereby, an upper end portion of the movable handle  49  is rotatably supported on the hold cylinder  48  via the support pins  57 . 
         [0206]    Ring-shaped finger hook portions  61  and  62  are provided on lower end portions of the stationary handle  47  and movable handle  49 , respectively. By hooking the fingers on the finger hook portions  61  and  62  and holding them, the movable handle  49  rotates via the support pins  57  and the movable handle  49  is opened/closed relative to the stationary handle  47 . 
         [0207]    The operation pins  58  of the movable handle  49  extend into the hold cylinder  48  through the window portions  60  of the hold cylinder  48 . An operation force transmission mechanism  63 , which transmits an operation force of the movable handle  49  to the driving pipe  19  of the jaw  17 , is provided inside the hold cylinder  48 . 
         [0208]    As shown in  FIG. 37 , the operation force transmission mechanism  63  mainly comprises a metallic cylindrical spring receiving member  64  and a resin-made slider member  65 . The spring receiving member  64  is disposed coaxially with the center axis of the hold cylinder  48 , and extends in the same direction as the direction of insertion of the probe unit  3 . 
         [0209]    A coil spring  67 , the slider member  65 , a stopper  68  and a spring receiver  69  are provided on an outer peripheral surface of the spring receiving member  64 . A front end portion of the coil spring  67  is fixed to the spring receiver  69 . The stopper  68  restricts the position of movement of a rear end side of the slider member  65 . The coil spring  67  is disposed between the spring receiver  69  and the slider member  65  with a fixed amount of mounting force. 
         [0210]    An annular engaging groove  65   a  is formed in a circumferential direction in an outer peripheral surface of the slider member  65 . As shown in  FIG. 38 , the operation pins  58  of the movable handle  49  are inserted and engaged in the engaging groove  65   a . If the movable handle  49  is held and the movable handle  49  is closed relative to the stationary handle  47 , the operation pins  58  rotate about the support pins  57  in accordance with the rotational operation of the movable handle  49  at this time. The slider member  65 , which is in interlock with the rotation of the support pins  57 , moves forward in the axial direction. At this time, the spring receiving member  64 , which is coupled to the slider member  65  via the coil spring  67 , moves forward/backward together with the slider member  65 . As shown in  FIG. 40 , a pair of engaging pins  45 , which are used when the sheath unit  5  and the handle unit  4  are attached/detached, are fixed to a distal end portion of the spring receiving member  64 . Thereby, the operation force of the movable handle  49  is transmitted to the connection tube body  34  of the sheath unit  5  via the pair of engaging pins  45 , and the driving pipe  19  of the jaw  17  moves forward. Thereby, the jaw body  201  of the jaw  17  rotates via the support pin  27 . 
         [0211]    Further, when a living body tissue is clamped between the hold member  202  of the jaw  17  and the probe distal end portion  3   a  of the probe unit  3  by this operation, the hold member  202  rotates over a certain angle about the pin  214  in accordance with the bending of the probe distal end portion  3   a  so that force uniformly acts over the entire length of the hold member  202 . In this state, ultrasonic is output and a living body tissue, such as a blood vessel, can be coagulated or cut. 
         [0212]    An annular bearing portion  70  is formed at a front end portion of the hold cylinder  48 . The bearing portion  70  is metallic, and a cylindrical rotation transmission member  71  is coupled to the bearing portion  70  rotatably about the axis. The rotation transmission member  71  includes a projecting portion  72  which projects forward of the bearing portion  70 , and a large-diameter portion  73  which extends to the inner side of the hold cylinder  48  from the bearing portion  70 . 
         [0213]    The rotational operation knob  50  is fitted and fixed on the projecting portion  72 . The engaging lever  43  is provided at the front end portion of the rotational operation knob  50 . An intermediate portion of the engaging lever  43  is rotatably coupled to the projecting portion  72  via a pin  74 . A proximal end portion of the engaging lever  43  extends to the inside of a lever receiving recess portion  75  which is formed in a front surface of the rotational operation knob  50 . 
         [0214]    An operation button  76  for operating the engaging lever  43  in such a direction as to disengage the engaging lever  43  is provided on an outer peripheral surface of the front end portion of the rotational operation knob  50 . An operation pin  77 , which is disposed downward, is provided so as to project from the operation button  76 . The operation pin  77  extends to the inside of the lever receiving recess portion  75  through a wall hole of the rotational operation knob  50 . A proximal end portion of the engaging lever  43  is rotatably coupled to a lower end portion of the operation pin  77  via a pin  78 . 
         [0215]    A removal prevention ring  80  for the rotational operation knob  50  is provided on a distal end portion of the projecting portion  72 . A male threaded portion  79  is formed on the distal end portion of the projecting portion  72 . A female threaded portion  80   a , which is to be meshed with the male threaded portion  79 , is formed on an inner peripheral surface of the removal prevention ring  80 . The female threaded portion  80   a  of the removal prevention ring  80  is meshed and engaged with the male threaded portion  79  of the projecting portion  72 , and thereby the rotational operation knob  50  is fixed to the rotation transmission member  71 . 
         [0216]    As shown in  FIG. 39 , the spring receiver  69  of the spring receiving member  64  is provided with four metallic positioning pins  81  which project radially outward. An elongated engaging hole portion  82 , in which one pin  81  of the spring receiving member  64  is inserted, is formed in the large-diameter portion  73  of the rotation transmission member  71 . The engaging hole portion  82  extends in the same direction as the direction of insertion of the probe unit  3 . Thereby, when the movable handle  49  is operated, the pin  81  is moved along the engaging hole portion  82  and thus the advancing/retreating movement of the spring receiving member  64  is prevented from being transmitted to the rotation transmission member  71 . 
         [0217]    On the other hand, when the rotational operation knob  50  is rotated, the rotational movement of the rotation transmission member  71 , which rotates together with the rotational operation knob  50 , is transmitted to the spring receiving member  64  via the pin  81 . Thereby, when the rotational operation knob  50  is rotated, the assembly unit of the rotation transmission member  71 , pin  81 , spring receiving member  64 , slider member  65  and coil spring  67  within the hold cylinder  48  is rotated together with the rotational operation knob as one body about the axis thereof. 
         [0218]    Engaging means  94 , which is disengageably engaged with the connection flange portion  33   c  of the sheath unit  5 , is provided on the inner peripheral surface of the rotation transmission member  71 .  FIGS. 41A and 41B  show the engaging means  94 . The engaging means  94  includes an insertion hole portion  94   a  in which the connection flange portion  33   c  is inserted when the sheath unit  5  and handle unit  4  are coupled, and an electrically conductive rubber ring (urging means)  94   b  which is disposed within the insertion hole portion  94   a.    
         [0219]    The shape of the inner peripheral surface of the electrically conductive rubber ring  94   b  is substantially the same as the shape of the engaging portion  46  of the connection flange portion  33   c . Specifically, the inner peripheral surface of the electrically conductive rubber ring  94   b  has three cut-out flat-surface portions  94   b    1  at a plurality of locations on the circular outer peripheral surface, for example, at three locations in this embodiment, and three corner portions  94   b   2  which are located at connection parts between the three flat-surface portions  94   b   1  and have greater diameters than the flat-surface portions  94   b . Thereby, the electrically conductive rubber ring  94   b  has a substantially triangular cross-sectional shape. Thus, as shown in  FIG. 41A , the electrically conductive rubber ring  94   b  is held in a natural, non-compressed position in the positional state in which the inner peripheral surface shape of the electrically conductive rubber ring  94   b  corresponds to the engaging portion  46  of the connection flange portion  33   c , that is, in the state in which the three corner portions  46   b  of the connection flange portion  33   c  correspond in position to the three corner portions  94   b   2  of the electrically conductive rubber ring  94   b . On the other hand, by rotating the handle unit  4  and the sheath unit  5  relative to each other about the center axis of the sheath unit  5 , the position of the electrically conductive rubber ring  94   b  is switched to a pressure contact position, as shown in  FIG. 41B , where the electrically conductive rubber ring  94   b  is pressed on the three corner portions  46   b  of the connection flange portion  33   c . At this time, the three corner portions  46   b  of the connection flange portion  33   c  are put in contact with, and pressed by, the three flat-surface portions  94   b    1  of the electrically conductive rubber ring  94   b.    
         [0220]    In the present embodiment, at the time of coupling the sheath unit  5  and handle unit  4 , when the connection flange portion  33   c  of the sheath unit  5  is inserted straight into the electrically conductive rubber ring  94   b  (see  FIG. 29  and  FIG. 30 ), the electrically rubber ring  94   b  is held in the natural, non-compressed position, as shown in  FIG. 41A . At this time, the engaging lever  43  on the handle unit  4  side is held in the state in which the engaging lever  43  rests on the inclined surface of the guide groove  41  of the handle member  32  of the sheath unit  5 . Subsequently, the handle member  32  of the sheath unit  5  is rotated about the axis, relative to the handle unit  4 . Thereby, as shown in  FIG. 31  and  FIG. 32 , the engaging lever  43  on the handle unit  4  side is inserted and engaged in the engaging recess portion  42  at one end portion of the guide groove  41 . At this time, as shown in  FIG. 41B , the electrically conductive rubber ring  94   b  is switched to the pressure contact position where the electrically conductive rubber ring  94   b  is put in pressure contact with the three corner portions  46   b  of the connection flange portion  33   c . Thereby, a sheath-unit-side electric path  40  (formed between the guide cylindrical body  33 , fixing screw  39 , coupling pipe  38 , sheath  18 , distal end cover  25 , support pin  27  and jaw body  28 ) and a handle-unit-side electric path  95  (formed between an electrical contact member  96 , spring receiving member  64 , positioning pin  81  and rotation transmission member  71 ) are electrically connected via the electrically conductive rubber ring  94   b . In this case, a second high-frequency electric path  97 , which transmits a high-frequency current, is formed in the coupled body of the sheath unit  5  and handle unit  4 . 
         [0221]    As shown in  FIG. 42 , the handle unit  4  includes a tubular member  98  which is formed of an insulating material on the inner peripheral surface of the spring receiving member  64 . The tubular member  98  is fixed on the inner peripheral surface of the spring receiving member  64 . Thereby, when the probe unit  3  and the handle unit  4  are connected, the first high-frequency electric path  13  and the second high-frequency electric path  97  are insulated by the tubular member  98 . 
         [0222]    An inner peripheral surface of the tubular member  98  has three engaging projection portions  99  which correspond to the three engaging recess portions  15  (see  FIG. 6 ) of the flange portion  14  of the probe unit  3 . When the probe unit  3  and handle unit  4  are connected, the three engaging projection portions  99  of the tubular member  98  are disengageably engaged with the three engaging recess portions  15  of the flange portion  14  of the probe unit  3 . Thereby, the rotational-directional position between the probe unit  3  and the tubular member  98  of the handle unit  4  is restricted. Hence, when the rotational operation knob  50  is rotated, the coupled body of the probe unit  3  and transducer unit  2  is rotated as one body together with the assembly unit within the hold cylinder  48 . 
         [0223]    The engaging section between the flange portion  14  of the probe unit  3  and the tubular member  98  is not limited to the above-described structure. For example, the tubular member  98  may be formed to have a D-shaped cross section, and the flange portion  14  of the probe unit  3  may be formed to have a corresponding D-shaped cross section. 
         [0224]      FIGS. 43 to 45  show a cylindrical contact-point unit  66  which is assembled to the hold cylinder  48 . The contact-point unit  66  includes a cylindrical electrode hold member  83  which is formed of a resin. As shown in  FIG. 45 , the electrode hold member  83  includes three (first to third) electrode receiving sections  84 ,  85  and  86  with different outside diameters. The first electrode receiving section  84  on the distal end side has a smallest diameter, and the third electrode receiving section  86  on the rear end side has a greatest diameter. 
         [0225]      FIG. 46  shows the first electrode receiving section  84 ,  FIG. 47  shows the second electrode receiving section  85 , and  FIG. 48  shows the third electrode receiving section  86 . 
         [0226]    As shown in  FIG. 46 , the first electrode receiving section  84  has one contact-point member fixing hole  84   a , and two through-holes  84   b  and  84   c . A center line of the two through-holes  84   b  and  84   c  is set to be perpendicular to a center line of the contact-point member fixing hole  84   a.    
         [0227]    Similarly, as shown in  FIG. 47 , the second electrode receiving section  85  has one contact-point member fixing hole  85   a , and two through-holes  85   b  and  85   c . As shown in  FIG. 48 , the third electrode receiving section  86  has one contact-point member fixing hole  86   a , and two through-holes  86   b  and  86   c.    
         [0228]    The positions of the contact-point member fixing hole  84   a  of the first electrode receiving section  84 , the contact-point member fixing hole  85   a  of the second electrode receiving section  85  and the contact-point member fixing hole  86   a  of the third electrode receiving section  86  are displaced in the circumferential direction of the electrode hold member  83 . 
         [0229]      FIG. 49  and  FIG. 50  show electrode members  87 A,  87 B and  87 C which are assembled to the first to third electrode receiving sections  84 ,  85  and  86 . These electrode members  87 A,  87 B and  87 C are formed in the same shape. In the description below, only the electrode member  87 A, which is assembled to the first electrode receiving section  84 , is described. The common parts of the electrode members  87 B and  87 C of the other second and third electrode receiving sections  85  and  86  are denoted by like reference numerals, and a description thereof is omitted. 
         [0230]    The electrode member  87 A includes one straight stationary portion  87   a  and two bend portions  87   b  and  87   c . One bend portion  87   b  is disposed at one end of the straight stationary portion  87   a , and the other bend portion  87   c  is disposed at the other end of the straight stationary portion  87   a . Thereby, as shown in  FIG. 49 , the electrode member  87 A is formed and bent in a substantially U shape. 
         [0231]    A hole  88  and an L-shaped wiring connection portion  89  are provided at a central position of the stationary portion  87   a . Inwardly curved waist portions  90  are formed at central positions of the two bend portions  87   b  and  87   c.    
         [0232]    When the first electrode receiving section  84  and the electrode member  87 A are assembled, a fixing pin  91  is inserted in the hole  88  of the stationary portion  87   a  of the electrode member  87 A and in the contact-point member fixing hole  84   a  of the first electrode receiving section  84 . The electrode member  87 A is fixed to the first electrode receiving section  84  by the fixing pin  91 . At this time, the waist portion  90  of one bend portion  87   b  of the electrode member  87 A is disposed in one through-hole  84   b  of the first electrode receiving section  84 , and the waist portion  90  of the other bend portion  87   c  of the electrode member  87 A is disposed in the other through-hole  84   c . The same applies when the electrode member  87 B is assembled to the second electrode receiving section  85  and the electrode member  87 C is assembled to the third electrode receiving section  86 . 
         [0233]    As shown in  FIG. 51 , a large-diameter fixing flange portion  83   a  is formed at a rear end portion of the electrode hold member  83  of the contact-point unit  66 . Engaging projection portions  83   b  are provided to project from the outer peripheral surface of the fixing flange portion  83   a  at a plurality of locations, for example, at three locations in this embodiment. Engaging recess portions  48   a  are formed in an inner peripheral surface of the rear end portion of the hold cylinder  48  at positions corresponding to the three engaging projection portions  83   b  of the stationary flange portion  83   a . In the case where the electrode hold member  83  is assembled in the hold cylinder  48 , the three engaging projection portions  83   b  of the stationary flange portion  83   a  are inserted, engaged and fixed in the engaging recess portions  48   a  of the hold cylinder  48 . Thereby, the rotation of the electrode hold member  83  about the axis thereof, relative to the hold cylinder  48 , is restricted. 
         [0234]    A stepped portion  43   b , which comes in contact with the fixing flange portion  83   a  of the electrode hold member  83 , is formed on the hold cylinder  48 . The electrode hold member  83  is fixed to the hold cylinder  48  by a fixing screw  48   c  in the state in which the fixing flange portion  83   a  of the electrode hold member  83  abuts upon the stepped portion  43   b . Thereby, the axial movement of the electrode hold member  83 , relative to the hold cylinder  48 , is restricted. 
         [0235]    End portions of three wiring lines  93   a  to  93   c , which are assembled in the switch hold section  51 , are connected to the wiring connection portions  89  of the three electrode members  87 A,  87 B and  87 C that are assembled to the contact-point unit  66 . 
         [0236]    Further, as shown in  FIG. 42 , the contact-point unit  66  is provided with a substantially C-shaped electric contact-point member  96  which is formed of a metallic plate spring. The electric contact-point member  96  is connected to the outer-peripheral surface of the proximal end portion of the spring receiving member  64 . 
         [0237]    The handle-unit-side electric path  95  is composed of the electrical contact member  96 , spring receiving member  64 , positioning pin  81  and rotation transmission member  71 . 
         [0238]    A front end portion of the transducer unit  2  is detachably coupled to the contact-point unit  66 . As shown in  FIG. 52 , two wiring lines  101  and  102  for the ultrasonic transducer, two wiring lines  103  and  104  for high-frequency power and three wiring lines  105 ,  106  and  107 , which are connected to a wiring circuit board within the switch hold section  51 , are assembled in the single cable  9  at the rear end of the transducer unit  2 . Distal end portions of the two wiring lines  101  and  102  for the ultrasonic transducer are connected to the ultrasonic transducer  6 . A distal end portion of one wiring line  103  for high-frequency power is connected to the ultrasonic transducer  6 . 
         [0239]    First to fourth electrically conductive plates  111  to  114  for electric connection are provided at the rear end of the transducer unit  2 . A distal end portion of the other wiring line  104  for high-frequency power is connected to the first conductive plate  111 . The three wiring lines  105 ,  106  and  107  are connected to the second to fourth conductive plates  112  to  114 . 
         [0240]      FIG. 4  shows the internal structure of a front end portion of the transducer unit  2 . A connection cylindrical portion  121  is formed at the distal end portion of the transducer cover  7 . A C-ring  122  having a partly cut-out annular plate shape is mounted on the outer peripheral surface of the connection cylindrical body  121 . Three (first to third) cylindrical portions  123  to  125  with different outside diameters are projectingly provided on the inside of the connection cylindrical portion  121 . The first cylindrical portion  123  has a smallest outside diameter and has a greatest length of projection from the distal end of the connection cylindrical body  121 . The second cylindrical portion  124  has an outside diameter, which is greater than the outside diameter of the first cylindrical portion  123 , and has a length of projection from the distal end of the connection cylindrical body  121 , which is less than the length of projection of the first cylindrical portion  123 . The third cylindrical portion  125  has a greatest outside diameter and has a length of projection from the distal end of the connection cylindrical body  121 , which is less than the length of projection of the second cylindrical portion  124 . 
         [0241]    A first cylindrical contact-point member  131  is mounted on the outer peripheral surface of the first cylindrical portion  123 . Similarly, a second cylindrical contact-point member  132  is mounted on the outer peripheral surface of the second cylindrical portion  124 , and a third cylindrical contact-point member  133  is mounted on the outer peripheral surface of the third cylindrical portion  125 . The second conductive plate  112  is connected to the first contact-point member  131 , the third conductive plate  113  is connected to the second contact-point member  132 , and the fourth conductive plate  114  is connected to the third contact-point member  133 . 
         [0242]    A fourth contact-point member  134  is mounted on the inner peripheral surface of the first cylindrical body  123 . The fourth contact-point member  134  is connected to the first conductive plate  111 . 
         [0243]    When the handle unit  4  and the transducer unit  2  are coupled, the contact-point unit  66  of the handle unit  4  and the front end portion of the transducer unit  2  are connected. At this time, the electrode member  87 A of the contact-point unit  66  and the first contact-point member  131  of the transducer unit  2  are connected. At the same time, the electrode member  87 B of the contact-point unit  66  and the second contact-point member  132  of the transducer unit  2  are connected, the electrode member  87 C of the contact-point unit  66  and the third contact-point member  133  of the transducer unit  2  are connected, and the C-shaped electric contact-point member  96  of the contact-point unit  66  and the fourth contact-point member  134  of the transducer unit  2  are connected. 
         [0244]    Next, the operation of the present embodiment is described. The handpiece  1  of the ultrasonic therapeutic apparatus of the present embodiment, as shown in  FIG. 2 , comprises four units, namely, the transducer unit  2 , probe unit  3 , handle unit  4  and sheath unit  5 , which are detachable. When the handpiece  1  is used, the transducer unit  2  and the probe unit  3  are coupled. Thereby, the first high-frequency electric path  13 , which transmits a high-frequency current to the coupled body of the transducer unit  2  and probe unit  3 , is formed. 
         [0245]    Subsequently, the handle unit  4  and the sheath unit  5  are coupled. When the handle unit  4  and sheath unit  5  are coupled, the connection tube body  34  is inserted in the rotation transmission member  71  of the handle unit  4  in the state in which the handle member  32  of the sheath unit  5  is held. When the sheath unit  5  and handle unit  4  are coupled, the engaging lever  43  on the handle unit  4  side is held in the state in which the engaging lever  43  rests on the inclined surface of the guide groove  41  of the handle member  32  of the sheath unit  5 , as shown in  FIG. 29  and  FIG. 30 . At this time, as shown in  FIG. 41A , the electrically conductive rubber ring  94   b  is held in the positional state in which the inner peripheral surface shape of the electrically conductive rubber ring  94   b  corresponds to the engaging portion  46  of the connection flange portion  33   c , that is, in the state in which the three corner portions  46   b  of the connection flange portion  33   c  correspond in position to the three corner portions  94   b   2  of the electrically conductive rubber ring  94   b . Accordingly, the connection flange portion  33   c  of the sheath unit  5  is inserted straight into the electrically conductive rubber ring  94   b . At the time of this insertion operation, as shown in  FIG. 41A , the conductive rubber ring  94   b  is held in the natural, non-compressed position. In this state, the sheath-unit-side electric path  40  and the handle-unit-side electric path  95  are not electrically connected. 
         [0246]    Subsequently, following this insertion operation, the handle member  32  of the sheath unit  5  is rotated about the axis thereof, relative to the handle unit  4 . By this operation, as shown in  FIG. 31  and  FIG. 32 , the engaging lever  43  on the handle unit  4  side is inserted and engaged in the engaging recess portion  42  at one end portion of the guide groove  41 . At this time, as shown in  FIG. 41B , the electrically conductive rubber ring  94   b  is switched to the pressure contact position where the electrically conductive rubber ring  94   b  is put in pressure contact with the three corner portions  46   b  of the connection flange portion  33   c . Thereby, the sheath-unit-side electric path  40  and the handle-unit-side electric path  95  are electrically connected via the electrically conductive rubber ring  94   b . As a result, the second high-frequency electric path  97 , which transmits a high-frequency current, is formed in the coupled body of the sheath unit  5  and handle unit  4 . 
         [0247]    When the sheath unit  5  is rotated about the axis thereof, the pair of engaging pins  45  on the handle unit  4  side are, at the same time, disengageably engaged in the engaging groove  44   a  at the terminal end portion of the guide groove  44  of the sheath unit  5 . Thereby, the spring receiving member  64  on the handle unit  4  side and the connection tube body  34  on the sheath unit  5  side are coupled via the engaging pins  45 . As a result, the operation force on the handle unit  4  side at the time when the movable handle  49  is closed relative to the stationary handle  47  can be transmitted to the driving pipe  19  of the jaw  17  on the sheath unit  5  side. This state is the coupled state between the sheath unit  5  and the handle unit  4 . 
         [0248]    Thereafter, the coupled body of the sheath unit  5  and handle unit  4  and the coupled body of the ultrasonic transducer  6  and probe unit  3  are assembled as one body. In this assembling work, the contact-point unit  66  of the handle unit  4  is connected to the front end portion of the transducer unit  2 . At this time, the electrode member  87 A of the contact-point unit  66  and the first contact-point member  131  of the transducer unit  2  are connected. At the same time, the electrode member  87 B of the contact-point unit  66  and the second contact-point member  132  of the transducer unit  2  are connected, the electrode member  87 C of the contact-point unit  66  and the third contact-point member  133  of the transducer unit  2  are connected, and the C-shaped electric contact-point member  96  of the contact-point unit  66  and the fourth contact-point member  134  of the transducer unit  2  are connected. Thereby, the second high-frequency electric path  97  of the coupled body of the sheath unit  5  and handle unit  4  is connected to the wiring line  104  for high-frequency power within the cable  9 . Further, the three wiring lines  105 ,  106  and  107  within the cable  9  are connected to the wiring circuit board within the switch hold section  51 . This state is the completion state of the assembly of the handpiece  1 . 
         [0249]    When the handpiece  1  is used, the movable handle  49  is opened/closed relative to the stationary handle  47 . The driving pipe  19  is axially moved in interlock with the operation of the movable handle  49 , and the jaw  17  is opened/closed, relative to the probe distal end portion  3   a  of the probe unit  3 , in interlock with the advancing/retreating movement of the driving pipe  19  in its axial direction. When the movable handle  49  is closed relative to the stationary handle  47 , the driving pipe  19  is pushed forward in interlock with the operation of the movable handle  49 . The jaw  17  is rotated and driven (to a closed position) in a direction toward the probe distal end portion  3   a  of the probe unit  3  in interlock with the pushing operation of the driving pipe  19 . By the rotation of the jaw  17  to its closed position, a living body tissue is held between the jaw  17  and the probe distal end portion  3   a  of the probe unit  3 . 
         [0250]    In this state, one of the switch button  54  for coagulation and the switch button  55  for incision, which are provided on the stationary handle  47 , is selectively pressed. When the switch button  54  for coagulation is pressed, power is supplied to the first high-frequency electric path  13  for supplying a high-frequency current to the probe distal end portion  3   a  of the probe unit  3  and to the second high-frequency electric path  97  for supplying a high-frequency current to the jaw body  28  of the sheath unit  5 . Thereby, the two bipolar electrodes for high-frequency therapeutic treatment are constituted by the probe distal end portion  3   a  of the probe unit  3  and the jaw body  28  of the sheath unit  5 . By supplying a high-frequency current between the two bipolar electrodes which are constituted by the probe distal end portion  3   a  of the probe unit  3  and the jaw body  28  of the sheath unit  5 , bipolar high-frequency therapeutic treatment can be performed for the living body tissue between the jaw  17  and the probe distal end portion  3   a  of the probe unit  3 . 
         [0251]    When the switch button  55  for incision is pressed, a driving current is supplied to the ultrasonic transducer  6  at the same time as the supply of high-frequency current, and the ultrasonic transducer  6  is driven. At this time, ultrasonic vibration from the ultrasonic transducer  6  is transmitted to the probe distal end portion  3   a  via the vibration transmission member  11 . Thereby, incision, resection, etc. of the living body tissue can be performed by making use of ultrasonic at the same time as the supply of high-frequency current. In the meantime, coagulation for the living body tissue can be performed by using ultrasonic. 
         [0252]    When the movable handle  49  is opened relative to the stationary handle  47 , the driving pipe  19  is pulled to the proximal side in interlock with the opening operation of the removable handle  49 . The jaw  17  is driven (to an open position) in a direction away from the probe distal end portion  3   a  of the probe unit  3  in interlock with the pulling operation of the driving pipe  19 . 
         [0253]    When the rotational operation knob  50  is rotated, the rotational movement of the rotation transmission member  71 , which rotates together with the rotational operation knob  50 , is transmitted to the spring receiving member  64  side via the pin  81 . Thereby, when the rotational operation knob  50  is rotated, the assembly unit of the rotation transmission member  71 , pin  81 , spring receiving member  64 , slider member  65  and coil spring  67  within the hold cylinder  48  is rotated together with the rotational operation knob  50  as one body about the axis thereof. Further, the rotational operation force of the rotational operation knob  50  is transmitted to the vibration transmission member  11  of the probe unit  3  via the tubular member  98  that rotates together with the spring receiving member  64  within the hold cylinder  48 . Thereby, the assembly unit within the hold cylinder  48  and the coupled body of the transducer unit  2  and probe unit  3  are rotated about the axis as one body. 
         [0254]    At this time, the handle member  32  and guide cylindrical body  33  of the sheath unit  5  rotate together with the rotational operation knob  50 . Furthermore, the sheath  18  rotates together with the guide cylindrical body  33 , and the rotation of the guide cylindrical body  33  is transmitted to the connection tube body  34  and driving pipe  19  via the threaded pin  235 . Thus, the jaw  17  and probe distal end portion  3   a  of the therapeutic section  1 A are rotated about the axis at the same time together with the rotational operation knob  50 . 
         [0255]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the handpiece  1  of the ultrasonic therapeutic apparatus of the present embodiment, the jaw  17  has the distal end chip  208  at a distal end portion of the engaging surface  206  for engagement with the probe distal end portion  3   a . When the jaw  17  and probe distal end portion  3   a  are engaged, a positional displacement relative to the probe distal end portion  3   a  is tolerated by the distal end chip  208 . Even in the case where a positional displacement occurs in the assembly position between the jaw  17  and the probe distal end portion  3   a  in the axial direction of the probe unit  3  when the probe unit  3  and the sheath unit  5  are assembled and the jaw  17  is positioned to face the probe distal end portion  3   a  of the probe unit  3 , the distal end of the probe distal end portion  3   a  can exactly be put in contact with the distal end chip  208  which is the insulator. As a result, a fixed amount of clearance can be kept between the electrode member  203  of the jaw  17  and the probe distal end portion  3   a  after assembly, and contact between the electrode member  203  of the jaw  17  and the probe distal end portion  3   a  can be prevented. Since the bipolar high-frequency therapeutic function can be secured, it is not necessary to precisely manage a fabrication error of parts of the apparatus and an error in assembly, and the manufacturing cost can be reduced. 
         [0256]    Moreover, in the present embodiment, in the jaw  17 , the entire distal end portion of the engaging surface  206  for engagement with the probe distal end portion  3   a  is formed by the distal end chip  208 . Thus, when the probe unit  3  and the sheath unit  5  are assembled, even if a positional displacement occurs in either the longitudinal direction or transverse direction between the jaw  17  and the probe distal end portion  3   a , the clearance between the electrode member  203  of the jaw  17  and the probe distal end portion  3   a  after assembly can surely be secured. 
         [0257]    As shown in  FIGS. 17 and 19 , the jaw  17  has, at the distal end portion of the groove portion  205 , the distal-end-side groove width varying section  205   t   1  which has such a tapering shape that the groove width of the groove portion  205  gradually increases toward the distal end. Thereby, when the probe unit  3  and the sheath unit  5  are assembled, even if a positional displacement occurs in either the longitudinal direction or transverse direction between the jaw  17  and the probe distal end portion  3   a , the positional displacement can be tolerated by the distal-end-side groove width varying section  205   t   1 . As a result, the clearance between the electrode member  203  of the jaw  17  and the probe distal end portion  3   a  after assembly can surely be secured. 
         [0258]    In addition, the jaw  17  has, at the proximal end portion of the groove portion  205 , the proximal-end-side groove width varying section  205   t   2  which has such a tapering shape that the groove width of the groove portion  205  gradually increases toward the proximal end. Thereby, when the probe unit  3  and the sheath unit  5  are assembled, even if a positional displacement occurs in either the longitudinal direction or transverse direction between the jaw  17  and the probe distal end portion  3   a , the positional displacement can be tolerated by the proximal-end-side groove width varying section  205   t   2 . As a result, the clearance between the electrode member  203  of the jaw  17  and the probe distal end portion  3   a  after assembly can surely be secured. 
         [0259]    The jaw  17  has the tooth portions  203   b  for preventing a slip, which are formed on both side walls  203   a  of the groove portion  205  of the electrode member  203 . Thus, when the jaw  17  and probe distal end portion  3   a  are engaged, the tooth portions  203   b  can be made to bite into a clamped object between the probe distal end portion  3   a  and the jaw  17 . Thereby, a slip of the clamped object between the probe distal end portion  3   a  and the jaw  17  can be prevented. 
         [0260]      FIG. 53  shows a second embodiment of the ultrasonic therapeutic apparatus of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows. In the jaw  17  of this embodiment, a plurality of substantially trapezoidal teeth  301  are juxtaposed on both side walls  203   a  of the electrode member  203 . 
         [0261]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the substantially trapezoidal teeth  301  are provided on the hold surface that comes in contact with a living body tissue. Thus, when the jaw  17  and probe distal end portion  3   a  are engaged, the trapezoidal teeth  301  can be made to bite into a clamped object between the probe distal end portion  3   a  and the jaw  17 . Thereby, a slip of the clamped object between the probe distal end portion  3   a  and the jaw  17  can be prevented. 
         [0262]    Furthermore, the trapezoidal teeth  301  have obtuse-angled corner portions, and have no acute-angled edge portions. In the case where the electrode member  203  of the jaw  17  has acute-angled edge portions, electricity concentrates at the acute-angled edge portions of the electrode member  203 . Consequently, a spark occurs between the edge portion of the jaw  17  and the probe distal end portion  3   a . Owing to the occurrence of the spark, heat will concentrate and the living body tissue may be burnt. By contrast, in the jaw  17  of this embodiment, since corner portions of the trapezoidal teeth  301  have obtuse-angled shapes, no spark occurs between the jaw  17  and the probe distal end portion  3   a , and burning of the living body tissue can be prevented. 
         [0263]      FIG. 54  shows a third embodiment of the ultrasonic therapeutic apparatus of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows. In the jaw  17  of this embodiment, a plurality of large-wavy-shaped teeth  302  are juxtaposed on both side walls  203   a  of the electrode member  203 . 
         [0264]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the large-wavy-shaped teeth  302  are provided on the hold surface that comes in contact with a living body tissue. Thus, when the jaw  17  and probe distal end portion  3   a  are engaged, the wavy-shaped teeth  302  can be made to bite into a clamped object between the probe distal end portion  3   a  and the jaw  17 . Thereby, a slip of the clamped object between the probe distal end portion  3   a  and the jaw  17  can be prevented. 
         [0265]    Furthermore, since the large-wavy-shaped teeth  302  have no corner portions and have gently curved shapes, no acute-angled edge portions are formed. In this embodiment, like the second embodiment (see  FIG. 53 ), no spark occurs between the jaw  17  and the probe distal end portion  3   a , and burning of the living body tissue can be prevented. 
         [0266]      FIG. 55  shows a fourth embodiment of the ultrasonic therapeutic apparatus of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows. In the jaw  17  of this embodiment, a plurality of small-wavy-shaped teeth  303  are juxtaposed on both side walls  203   a  of the electrode member  203 . 
         [0267]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the small-wavy-shaped teeth  303  are provided on the hold surface that comes in contact with a living body tissue. Thus, when the jaw  17  and probe distal end portion  3   a  are engaged, the wavy-shaped teeth  303  can be made to bite into a clamped object between the probe distal end portion  3   a  and the jaw  17 . Thereby, a slip of the clamped object between the probe distal end portion  3   a  and the jaw  17  can be prevented. 
         [0268]    Furthermore, since the small-wavy-shaped teeth  303  have no corner portions and have gently curved shapes, no acute-angled edge portions are formed. In this embodiment, like the second embodiment (see  FIG. 53 ), no spark occurs between the jaw  17  and the probe distal end portion  3   a , and burning of the living body tissue can be prevented. 
         [0269]      FIG. 56  shows a fifth embodiment of the ultrasonic therapeutic apparatus of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows. In the jaw  17  of this embodiment, planar hold surfaces  304  with no teeth are formed on both side walls  203   a  of the electrode member  203 . 
         [0270]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the planar hold surfaces  304  on both side walls  203   a  of the electrode member  203  are put in contact with a living body tissue. Thus, no spark occurs between the jaw  17  and the probe distal end portion  3   a , and burning of the living body tissue can be prevented. 
         [0271]      FIGS. 57 to 61  show a sixth embodiment of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows.  FIG. 57  shows the external appearance of the jaw  17  of this embodiment. As shown in  FIGS. 58 and 59 , in the jaw  17  of this embodiment, the pad member  207 , which is formed of an insulator, has an outer contact surface that comes in contact with the probe distal end portion  3   a , and this contact surface is provided with a wear-prevention portion  311  for preventing wear of the pad member  207 . 
         [0272]      FIG. 60  shows the external appearance of the pad member  207 . A mounting groove  312  for mounting the wear-prevention portion  311  is provided in the outer contact surface of the pad member  207 , which comes in contact with the probe distal end portion  3   a . Further, a front end fixing portion  313   a  for fixing a front end of the wear-prevention portion  311  is formed at a front end portion of the pad member  207 , and a rear end fixing portion  313   b  for fixing a rear end of the wear-prevention portion  311  is formed at a rear end portion of the pad member  207 . 
         [0273]    The wear-prevention portion  311  in this embodiment includes, for example, an elongated plate-shaped metallic pad  314  which is formed of a metallic material.  FIG. 61  shows the metallic pad  314 . A front end bend portion  315 , which is attached to the front end fixing portion  313   a  of the pad member  207 , is formed at a front end portion of the metallic pad  314 . Similarly, a rear end bend portion  316 , which is attached to the rear end fixing portion  313   b  of the pad member  207 , is formed at a rear end portion of the metallic pad  314 . 
         [0274]    The front end bend portion  315  of the metallic pad  314  is attached to the front end fixing portion  313   a  of the pad member  207 , and the rear end bend portion  316  of the metallic pad  314  is attached to the rear end fixing portion  313   b  of the pad member  207 . In addition, the metallic pad  314  is inserted in the mounting groove  312  of the pad member  207 . In this state, the metallic pad  314  is fixed to the pad member  207 . As shown in  FIG. 59 , the pad member  207  is interposed between the metallic pad  314  and the electrode member  203 . Thereby, the metallic pad  314  and the electrode member  203  are electrically insulated. 
         [0275]    The following advantageous effect can be obtained by the above-described structure. Specifically, in the jaw  17  of this embodiment, the outer contact surface of the pad member  207 , which comes in contact with the probe distal end portion  3   a , has the metallic pad  314  for preventing wear of the pad member  207 . Thereby, the pad member  207  of the jaw  17  is prevented from coming in direct contact with the probe distal end portion  3   a . Therefore, the pad member  207  of the jaw  17  can be prevented from being worn due to contact with the probe distal end portion  3   a . As a result, the wear-resistance properties of the part of the jaw  17 , which comes in contact with the probe distal end portion  3   a , can be improved. 
         [0276]    The wear-prevention portion  311  is not necessarily limited to the metallic pad  314  of the metallic material. For instance, the wear-prevention portion  311  may be formed of a ceramic material, a hard resin material, etc. 
         [0277]      FIGS. 62 to 68  show a seventh embodiment of the present invention. In this embodiment, the structure of the jaw  17  in the sixth embodiment of the invention (see  FIG. 57  to  FIG. 61 ) is altered as follows. 
         [0278]    Specifically, in this embodiment, a metallic pad  314  is assembled to an insulation member  204  shown in  FIG. 63  by bending a metallic plate  321  shown in  FIG. 64 . A recess-shaped front end fixing portion  313   a  for fixing a front end of the metallic pad  314  is formed at a front end portion of the insulation member  204 , and a recess-shaped rear end fixing portion  313   b  for fixing a rear end of the metallic pad  314  is formed at a rear end portion of the insulation member  204 . 
         [0279]      FIG. 64  shows a metallic plate  321  prior to bending of the metallic pad  314  of the jaw  17 . A front end bend portion  322 , which is bent substantially at right angles, is formed at a front end portion of the metallic plate  321 . A small bend portion  323 , which is bent at right angles, is further formed at a distal end portion of the front end bend portion  322 . A substantially L-shaped bend portion  324  is formed of the front end bend portion  322  and the small bend portion  323 . A rear end bend portion  325 , which is bent substantially at right angles, is formed at a rear end portion of the metallic plate  321 . 
         [0280]      FIG. 65  illustrates a first step of assembling the metallic pad  314  to the insulation member  204  of the jaw  17 . In this step, the L-shaped bend portion  324  of the metallic plate  321  is engaged and fixed in the front end fixing portion  313   a  of the insulation member  204 . 
         [0281]      FIG. 66  illustrates a second step of assembling the metallic pad  314  to the insulation member  204  of the jaw  17 . In this step, the metallic plate  321  shown in  FIG. 65  is further bent in the vicinity of the L-shaped bend portion  324  in accordance with the shape of the front end fixing portion  313   a  of the insulation member  204 . The rear end bend portion  325  of the metallic plate  321  is moved to the position of the rear end fixing portion  313   b  of the insulation member  204 . 
         [0282]      FIG. 67  illustrates a third step of assembling the metallic pad  314  to the insulation member  204  of the jaw  17 . In this step, the rear end bend portion  325  of the metallic plate  321  shown in  FIG. 66  is further bent in accordance with the shape of the rear end fixing portion  313   b  of the insulation member  204 . The rear end bend portion  325  of the metallic plate  321  is engaged and fixed in the rear end fixing portion  313   b  of the insulation member  204 . Thereby, the bending process for assembling the metallic pad  314  to the insulation member  204  of the jaw  17  is completed.  FIG. 68  shows the shape of the metallic pad  314  of the jaw  17  after the bending process. 
         [0283]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the metallic pad  314  is assembled to the insulation member  204  shown in  FIG. 63  by bending the metallic plate  321  shown in  FIG. 64 . Therefore, the metallic pad  314  can be assembled in the insulation member  204  by a simple work, and the jaw  17  can be manufactured at low cost. 
         [0284]      FIG. 69  and  FIG. 70  show an eighth embodiment of the present invention. In this embodiment, the structure of the jaw  17  in the fifth embodiment of the invention (see  FIG. 56 ) is altered as follows. 
         [0285]    Specifically, in the jaw  17  of this embodiment, planar hold surfaces  304  with no teeth are formed on both side walls  203   a  of the electrode member  203 . Further, a plurality of teeth  331  are juxtaposed on the outer contact surface of the pad member  207  of the insulator, which comes in contact with the probe distal end portion  3   a.    
         [0286]    The following advantageous effects can be obtained by the above-described structure. Specifically, in the jaw  17  of the present embodiment, the planar hold surfaces  304  on both side walls  203   a  of the electrode member  203  are put in contact with a living body tissue. Thus, no spark occurs between the jaw  17  and the probe distal end portion  3   a , and burning of the living body tissue can be prevented. 
         [0287]    Moreover, in the present embodiment, the plural teeth  331  are juxtaposed on the outer contact surface of the pad member  207 , which comes in contact with the probe distal end portion  3   a . Thus, when the jaw  17  and probe distal end portion  3   a  are engaged, the teeth  331  of the pad member  207  can be made to bite into a clamped object between the probe distal end portion  3   a  and the jaw  17 . Thereby, a slip of the clamped object between the probe distal end portion  3   a  and the jaw  17  can be prevented. 
         [0288]      FIG. 71  shows a ninth embodiment of the present invention. In this embodiment, the structure of the jaw  17  in the first embodiment (see  FIG. 1  to  FIG. 52 ) is altered as follows. Specifically, in this embodiment, the distal end chip  208  at the distal end portion of the jaw  17  is dispensed with. In addition, the distal-end-side groove width varying section  205   t   1 , which is provided at the distal end portion of the groove portion  205  of the electrode member  203  of the jaw  17 , is extended to the distal end of the electrode member  203 . 
         [0289]    In the above-described structure, the electrode member  203  can be extended up to the foremost distal end of the jaw  17 . Therefore, when therapeutic treatment by the handpiece  1  is performed, the high-frequency therapeutic treatment can be performed up to the foremost position of the jaw  17 , and thus the range of high-frequency therapeutic treatment by the jaw  17  can be increased. 
         [0290]    Needless to say, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the invention. 
         [0291]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.