Patent Publication Number: US-2012029395-A1

Title: Ultrasound operation system and surgical treatment instrument

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of PCT/JP2011/057357 filed on Mar. 25, 2011 and claims benefit of U.S. Provisional Patent Application No. 61/322,510 filed in the U.S.A. on Apr. 9, 2010, the entire contents of which are incorporated herein by this reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an ultrasound operation system and a surgical treatment instrument, and particularly relates to an ultrasound operation system and a surgical treatment instrument which perform amplitude regulation of an ultrasound transducer. 
     2. Description of the Related Art 
     Conventionally, as an operation system for a surgical operation, an ultrasound operation system has been developed, which dissects or coagulates a living tissue by using an ultrasound probe which is ultrasound-vibrated. 
     In such an ultrasound operation system, for example, an amplitude value of an ultrasound probe varies depending on a component variation or an assembly variation of an ultrasound transducer, or a component variation or an assembly variation of the ultrasound probe. When the value of the amplitude is large, stress of the ultrasound probe increases. 
     Further, for example, when a hand piece is in a shape of scissors, a grasping force amount of a handle varies depending on a component variation or an assembly variation. When the grasping force amount is small, a dissection speed decreases, and when the grasping force amount is large, wear promotion of a Teflon pad and stress of the ultrasound probe increase. 
     Furthermore, for example, a hardness of a site to be treated which a surgeon treats differs in accordance with a site. When the site to be treated is a thin tissue, a dissection speed decreases, whereas when the site to be treated is a hard tissue, the stress of an ultrasound probe increases and/or a main apparatus cannot output ultrasound in some cases. 
     Consequently, for example, Japanese Patent Application Laid-Open Publication No. 2005-27907 proposes an ultrasound operation system which detects impedance at a drive time of an ultrasound transducer, and performs control of a drive signal which is supplied to the ultrasound transducer. 
     SUMMARY OF THE INVENTION 
     An ultrasound operation system of one aspect of the present invention includes a drive current generating portion, a surgical treatment instrument including an object to be driven including an ultrasound transducer which is driven by the drive current generating portion, and a treatment portion which is connected to the ultrasound transducer to perform treatment of a living tissue by an ultrasound vibration generated in the ultrasound transducer, and an amplitude regulating portion which is provided between the drive current generating portion and the object to be driven, and performs regulation of an amplitude of the ultrasound transducer by diverting a current which flows into the object to be driven from the drive current generating portion in accordance with a state of a load exerted on the treatment portion and regulating an amount of a current which flows into the object to be driven. 
     Further, a surgical treatment instrument of another aspect of the present invention includes an object to be driven including an ultrasound transducer, and an amplitude regulating portion which is provided in parallel with the object to be driven, diverts a current which flows into the object to be driven and is for driving the object to be driven, and performs regulation of an amplitude of the ultrasound transducer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing a configuration of an ultrasound operation system according to an embodiment of the present invention. 
         FIG. 2  is a diagram showing an equalizing circuit of the ultrasound operation system before ultrasound output of the present embodiment. 
         FIG. 3  is a diagram showing the equalizing circuit of the ultrasound operation system during ultrasound output of the present embodiment. 
         FIG. 4  is an explanatory diagram for explaining a relationship of a non-inductive resistance value and a current which is supplied to an ultrasound transducer. 
         FIG. 5  is an explanatory diagram for explaining a relationship of a load on a treatment portion and a current which is supplied to the ultrasound transducer. 
         FIG. 6  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and an oscillation efficiency of a main apparatus. 
         FIG. 7  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and a dissection time. 
         FIG. 8  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and a vascular withstanding pressure average value. 
         FIG. 9  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and a number of dissection times. 
         FIG. 10  is a diagram showing an equalizing circuit of a conventional ultrasound operation system. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     (Entire Configuration) 
       FIG. 1  is a view showing a configuration of an ultrasound operation system according to an embodiment of the present invention. An ultrasound operation system  1  is configured by including a hand piece  2 , a main apparatus  3  that is an output control apparatus, and a foot switch  4 . 
     The hand piece  2  is a surgical treatment instrument capable of outputting ultrasound. The hand piece  2  is connected to the main apparatus  3  via a cable  2   a  which is attachable and detachable. The hand piece  2  has an insertion portion  2   b  and a handle portion  2   c.  Further, the hand piece  2  contains an object to be driven including an ultrasound transducer  2   f.  The ultrasound transducer  2   f  has a vibration block which is configured into a cylindrical shape in such a manner that a plurality of piezoelectric elements each formed into a donut shape are stacked to sandwich a plurality of annular electrodes which are disposed between adjacent piezoelectric elements. Further, a bolt is penetrated through through-holes in centers of the piezoelectric elements and the electrodes which are stacked, and the bolt is screwed into a horn portion, whereby the ultrasound transducer  2   f  is configured so that the piezoelectric elements and the electrodes are firmly brought into close contact with one another. The ultrasound transducer  2   f  is a unit of a Langevin type bolted ultrasound transducer. 
     Furthermore, the hand piece  2  has an ultrasound probe  2   d,  and at a distal end side of the ultrasound probe  2   d,  a treatment portion  2   e  is formed by a distal end portion of the ultrasound probe  2   d  and a movable piece which is openable and closable with respect to the distal end portion. 
     The main apparatus  3  supplies a drive signal for ultrasound output to the ultrasound transducer  2   f  contained in the hand piece  2 . The ultrasound transducer  2   f  ultrasound-vibrates by being supplied with the drive signal. The ultrasound vibration is transmitted to the distal end portion of the ultrasound probe  2   d  via the ultrasound probe  2   d  in the insertion portion  2   b.  The hand piece  2  can generate a friction heat in a living tissue of an object to be treated, and can perform treatment such as coagulation, dissection, and the like. 
     The foot switch  4  is connected to the main apparatus  3  via a cable  4   a.  The foot switch  4  is a switch for turning on or off ultrasound output at the time of ultrasound output. 
     A surgeon pulls a wire (not illustrated) which is inserted in the insertion portion  2   b  by putting a finger on the handle portion  2   c  and performing an opening and closing operation to open and close a movable piece in the treatment portion  2   e  to be able to grasp a living tissue which is the object to be treated. Further, the surgeon can perform, for example, a laparoscopic surgical operation with the hand piece  2  in one hand, and another treatment instrument in the other hand. 
     Here, an equalizing circuit of a conventional ultrasound operation system will be described.  FIG. 10  is a diagram showing the equalizing circuit of the conventional ultrasound operation system. 
     As shown in  FIG. 10 , an ultrasound transducer  104  provided in a hand piece  102  of an ultrasound operation system  101  is configured by a series resonance circuit in which a resistor R 1 , a capacitor C 1  and a coil L 1  are connected in series, and a capacitor C 2  connected in parallel to the series circuit. 
     A main apparatus  103  of the ultrasound operation system  101  is configured by an output transformer Tr, and a coil L 2  which is connected to the output transformer Tr in parallel. A signal which is oscillated by an oscillation circuit not illustrated is supplied to a primary winding of the output transformer Tr, and a drive signal for ultrasound output is generated in a secondary winding of the output transformer Tr. 
     The coil L 2  is a coil for performing matching of impedance for the drive signal so as to be able to supply the drive signal efficiently to the ultrasound transducer  104 . A current I 1  which is generated in the output transformer Tr, and a current I 1 +I′ which is a total of the current I 1  which is generated in the output transformer Tr and a reactive current I′ which is generated in the coil L 2  is supplied to the hand piece  102  via the aforementioned cable  2   a.    
     Of the current I 1 +I′ which is supplied to the hand piece  102 , the reactive current I′ is diverted to the capacitor C 2 , and the current I 1  is supplied to the series resonance circuit configured by the resistor R 1 , the capacitor C 1  and the coil L 1 . In this manner, the current I 1  which is generated in the output transformer Tr is supplied to the series resonance circuit. The series resonance circuit resonates in accordance with the value of the current I 1 , and the ultrasound transducer  104  ultrasound-vibrates. 
     The conventional ultrasound operation system  101  cannot regulate the current I 1  which is generated in the output transformer Tr. Therefore, an amplitude value of a treatment portion varies depending on a component variation or an assembly variation of the ultrasound transducer  104 , or a component variation or an assembly variation of the ultrasound probe. Further, in order to regulate the current I 1  which is generated in the output transformer Tr, the impedance at a drive time of the ultrasound transducer  104  needs to be sensed and fed back to the main apparatus, and a control program and a control section for performing feedback control need to be provided in the main apparatus. 
       FIG. 2  is a diagram showing an equalizing circuit of the ultrasound operation system before ultrasound output of the present embodiment. In  FIG. 2 , the same components as in  FIG. 10  are assigned with the same reference numerals and characters, and the description thereof will be omitted. 
     As shown in  FIG. 2 , the ultrasound operation system  1  is provided with a non-inductive resistor R 2  in parallel between the output transformer Tr and the ultrasound transducer  2   f.  The non-inductive resistor R 2  as an amplitude regulating portion diverts a current which is supplied to the ultrasound transducer  2   f  from the output transformer Tr as a drive current generating portion. Further, the non-inductive resistor R 2  is provided at the hand piece  2  side, and the value of the non-inductive resistor R 2  is the value substantially the same as a value of the resistor R 1 . The non-inductive resistor R 2  as the amplitude regulating portion is provided at the hand piece  2  side, but may be provided at the main apparatus  3  side. Further, the amplitude regulating portion may be a resistor instead of the non-inductive resistor R 2 . 
     A value of a current I 3  of the output transformer Tr is determined so that when a current I 2  is diverted to the non-inductive resistor R 2 , the current I 1  flows into the ultrasound transducer  2   f.  More specifically, the value of the current I 3  is a value which is obtained by addition of a value of the current I 1  and a value of the current I 2 . Whereby, the series resonance circuit resonates in accordance with the value of the current I 1 , and the ultrasound transducer  2   f  ultrasound-vibrates. 
       FIG. 3  is a diagram showing an equalizing circuit of the ultrasound operation system during ultrasound output of the present embodiment. 
     In the ultrasound operation system  1 , the capacitor C 1  and the coil L 2 , and the capacitor C 2  and the coil L 2  cancel out each other in the resonating state during ultrasound output. Accordingly, the equalizing circuit of the ultrasound operation system  1  has only the non-inductive resistor R 2  and the resistor R 1  of the ultrasound transducer  2   f.  The current I 1  which flows into the resistor R 1  is converted into ultrasound vibration, and a distal end portion of the ultrasound probe  2   d  vibrates with a predetermined amplitude value. 
     Here, the current I 1  which is supplied to the ultrasound transducer  2   f  will be described with use of  FIGS. 4 and 5 . 
       FIG. 4  is an explanatory diagram for explaining a relationship of the non-inductive resistance value and the current which is supplied to the ultrasound transducer. 
     As shown in  FIG. 4 , when the value of the non-inductive resistor R 2  increases to a×7[Ω] from a[Ω], the value of the current I 1  which is supplied to the resistor R 1  of the ultrasound transducer  2   f  increases to I 12 [A] from I 11 [A]. This is because the current I 2  which is diverted to the non-inductive resistor R 2  decreases as the value of the non-inductive resistor R 2  becomes larger. More specifically, when the value of the non-inductive resistor R 2  is large, the current I 2  which is diverted to the non-inductive resistor R 2  decreases, and therefore, the current I 1  which flows into the resistor R 1  of the ultrasound transducer  2   f  increases. Meanwhile, when the value of the non-inductive resistor R 2  is small, the current I 2  which is diverted to the non-inductive resistor R 2  increases, and therefore, the current I 1  which flows into the resistor R 1  of the ultrasound transducer  2   f  decreases. 
       FIG. 5  is an explanatory diagram for explaining a relationship of a load on the treatment portion and a current which is supplied to the ultrasound transducer. In an example of  FIG. 5 , the non-inductive resistor R 2  is fixed to a predetermined value, and the load (voltage) on the treatment portion  2   e  is changed. The load on the treatment portion  2   e  is equivalent to the load on the ultrasound transducer  2   f.  More specifically, increase in the load on the treatment portion  2   e  is equivalent to increase in the value of the resistor R 1  of the ultrasound transducer  2   f,  and decrease in a load on the treatment portion  2   e  is equivalent to decrease in the value of the resistor R 1  of the ultrasound transducer  2   f.    
     As shown in  FIG. 5 , when the load on the treatment portion  2   e  increases to b×2[V] from b[V], the value of the current I 1  which is supplied to the resistor R 1  of the ultrasound transducer  2   f  decreases to I 14 [A] from I 13 [A]. This is because the value of the resistor R 1  becomes larger as the load on the treatment portion  2   e  becomes larger, and the current I 1  which is diverted to the resistor R 1  decreases. 
     As above, when the noninductive resistor R 2  is fixed to the predetermined value, the current which flows into the ultrasound transducer  2   f  is regulated in accordance with the load on the treatment portion  2   e,  and the amplitude value of the ultrasound transducer  2   f  can be regulated. 
     Here, the technical problem during treatment will be described with use of  FIGS. 6 to 9 . 
       FIG. 6  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and the oscillation efficiency of the main apparatus. 
     When the amplitude value of the treatment portion  2   e  is A 2  which is a target (hereinafter, also called a central value), the oscillation efficiency of the main apparatus  3  is c×0.8[%]. When the amplitude value of the treatment portion  2   e  is A 1  which is smaller than the central value, the oscillation efficiency of the main apparatus  3  is c[%]. When the amplitude value of the treatment portion  2   e  is A 3  which is larger than the central value, the oscillation efficiency of the main apparatus  3  is c×0.6[%]. 
     As above, when the amplitude value of the treatment portion  2   e  changes by about several tens μm from A 1  to A 3 , the oscillation efficiency of the main apparatus  3  is reduced by about 40%. When the amplitude value of the treatment portion  2   e  becomes large, the oscillation efficiency of the main apparatus  3  is reduced. When the amplitude value of the treatment portion  2   e  further becomes larger to be an amplitude value outside a certain specified range, the oscillation efficiency of the main apparatus  3  is further reduced and ultrasound output cannot be performed. 
       FIG. 7  is an explanatory diagram for explaining a relationship of the amplitude value of the treatment portion and a dissection time. The dissection time of  FIG. 7  is a time which is taken when a certain tissue is dissected by 20 cm. 
     As shown in  FIG. 7 , when the amplitude value of the treatment portion  2   e  is B 2  which is a central value, the dissection time is T[S]. When the amplitude value of the treatment portion  2   e  is B 1  which is smaller than the central value, the dissection time is T×2.5[S] which is about 2.5 times as large as T[S]. When the amplitude value of the treatment portion  2   e  is B 3  which is larger than the central value, the dissection time is T/2[S] which is about ½ of T[S]. 
     As above, when the amplitude value of the treatment portion  2   e  decreases, the dissection speed decreases, and the treatment time becomes long. Meanwhile, when the amplitude value of the treatment portion  2   e  is large, the dissection speed increases, but the stress of the ultrasound probe increases. 
       FIG. 8  is an explanatory diagram for explaining a relationship of the treatment portion amplitude value and a vascular withstanding pressure average value. 
     When the amplitude value of the treatment portion  2   e  is C 2  which is a central value, the vascular withstanding pressure average value is about d×0.6 [mmHg]. When the amplitude value of the treatment portion  2   e  is C 1  which is smaller than the central value, the vascular withstanding pressure average value is about d[mmHg]. When the amplitude value of the treatment portion  2   e  is C 3  which is larger than the central value, the vascular withstanding pressure average value is about d×0.3[mmHg]. 
     As above, when the amplitude value of the treatment portion  2   e  increases, the vascular withstanding pressure ability is reduced by about 70%. 
       FIG. 9  is an explanatory view for explaining a relationship of the treatment portion amplitude value and the number of dissection times. 
     As shown in  FIG. 9 , when the amplitude value of the treatment portion  2   e  is D 2  which is a central value, the number of dissection times is N. When the amplitude value of the treatment portion  2   e  is D 1  which is smaller than the central value, the number of dissection times is 2N which is twice as compared with the dissection times when the amplitude value is the central value. When the amplitude value of the treatment portion  2   e  is D 3  which is larger than the central value, the number of dissection times becomes 2/N which is ½ times as compared with the dissection times when the amplitude value is the central value. 
     As above, when the amplitude value of the treatment portion  2   e  increases, the number of dissection times decreases. This is because when the amplitude value of the treatment portion  2   e  increases, the Teflon pad of the treatment portion  2   e  easily wears. When the Teflon pad of the treatment portion  2   e  reaches a failure mode in which the Teflon pad is worn, the ultrasound probe  2   d  and the movable piece are in contact with each other, and a crack occurs to the ultrasound probe  2   d.    
     Here, control of the amplitude value of the treatment portion  2   e  in the case of the amplitude value of the treatment portion  2   e  varying due to a component variation or the like of the ultrasound transducer  2   f  or the like will be described. 
     When the amplitude value of the treatment portion  2   e  is around the central value, the load on the treatment portion  2   e  is around the central value. In this case, the value of the resistor R 1  of the ultrasound transducer  2   f  does not vary, and the current I 2  which is diverted to the non-inductive resistor R 2  and the current I 1  which flows into the resistor R 1  do not vary. Since the current I 1  which flows into the resistor R 1  does not vary like this, the amplitude value of the treatment portion  2   e  does not vary. 
     When the amplitude value of the treatment portion  2   e  is lower than a value around the central value, the load on the treatment portion  2   e  becomes small. This case is equivalent to the value of the resistor R 1  of the ultrasound transducer  2   f  becoming small, and the current I 2  which is diverted to the non-inductive resistor R 2  decreases, whereas the current I 1  which flows to the resistor R 1  increases. 
     When the amplitude value of the treatment portion  2   e  is lower than a value around the central value, the problem of reducing the dissection speed arises. However, when the amplitude value of the treatment portion  2   e  is lower than the value around the central value like this, the current I 1  which flows into the resistor R 1  increases, and therefore, the amplitude value of the treatment portion  2   e  increases, and reduction in the dissection speed can be suppressed. 
     When the amplitude value of the treatment portion  2   e  is higher than a value around the central value, the load on the treatment portion  2   e  becomes large. This case is equivalent to the value of the resistor R 1  of the ultrasound transducer  2   f  becoming large, and the current I 2  which is diverted to the non-inductive resistor R 2  increases, whereas the current I 1  which flows into the resistor R 1  decreases. 
     When the amplitude value of the treatment portion  2   e  is higher than a value around the central value, there arise the problems of reduction in a vascular withstanding pressure ability, promotion of wear of the Teflon pad and increases in stress of the ultrasound probe. However, when the amplitude value of the treatment portion  2   e  is higher than a value around the central value like this, the current I 1  which flows into the resistor R 1  decreases. Therefore, the amplitude value of the treatment portion  2   e  decreases, reduction in the vascular withstanding pressure ability, promotion of wear of the Teflon pad and increase in stress of the ultrasound probe can be suppressed. 
     Next, control of the amplitude value of the treatment portion  2   e  in the case in which the grasping force amount of the handle  2   c  varies due to a component variation or the like of the handle  2   c  will be described. 
     When the grasping force amount is around the central value, the load on the treatment portion  2   e  is around the central value. In this case, the value of the resistor R 1  of the ultrasound transducer  2   f  does not vary, and the current I 2  which is diverted to the non-inductive resistor R 2  and the current I 1  which flows into the resistor R 1  do not vary. Accordingly, the current I 1  which flows into the resistor R 1  does not vary, and therefore, the amplitude value of the treatment portion  2   e  does not vary. 
     When the grasping force amount is lower than a value around the central value, the load on the treatment portion  2   e  becomes small. This case is equivalent to the value of the resistor R 1  of the ultrasound transducer  2   f  becoming small, and the current I 2  which is diverted to the non-inductive resistor R 2  decreases, whereas the current I 1  which flows into the resistor R 1  increases. 
     When the grasping force amount is lower than a value around the central value, there arises the problem of reducing the dissection speed. However, since when the grasping force amount is lower than a value around the central value, the current I 1  which flows into the resistor R 1  increases, the amplitude value of the treatment portion  2   e  increases, and reduction in the dissection speed can be suppressed. 
     When the grasping force amount is higher than a value around the central value, the load on the treatment portion  2   e  becomes large. This case is equivalent to the value of the resistor R 1  of the ultrasound transducer  2   f  becoming large, the current I 2  which is diverted into the noninductive resistor R 2  increases, whereas the current I 1  which flows into the resistor R 1  decreases. 
     When the grasping force amount is higher than a value around the central value, there arise the problems of promotion of wear of the Teflon pad, and increase in stress of the ultrasound probe. However, since when the grasping force amount is higher than a value around the central value like this, the current I 1  which flows into the resistor R 1  decreases, the amplitude value of the treatment portion  2   e  decreases, and promotion of the wear of the Teflon pad and increase in stress of the ultrasound probe can be suppressed. 
     Next, control of the amplitude value of the treatment portion  2   e  in the case of a hardness of a site to be treated varying will be described. 
     When the site to be treated is an ordinary tissue such as a vessel, the load on the treatment portion  2   e  becomes a value around the central value. In this case, the value of the resistor R 1  of the ultrasound transducer  2   f  does not vary, and the current I 2  which is diverted to the non-inductive resistor R 2  and the current I 1  which flows into the resistor R 1  do not vary. Accordingly, the current I 1  which flows into the resistor R 1  does not vary, and therefore, the amplitude value of the treatment portion  2   e  does not vary. 
     When the site to be treated is a thin tissue such as a mesenterium, the load on the treatment portion  2   e  becomes small. This case is equivalent to decrease in the value of the resistor R 1  of the ultrasound transducer  2   f,  and the current I 2  which is diverted to the non-inductive resistor R 2  decreases, whereas the current I 1  which flows into the resistor R 1  increases. 
     When the site to be treated is a thin tissue such as a mesenterium, there arises the problem that the dissection speed is reduced. However, since when the site to be treated is a thin tissue such as a mesenterium like this, the current I 1  which flows into the resistor R 1  increases, the amplitude value of the treatment portion  2   e  increases, and reduction in the dissection speed can be suppressed. 
     When the site to be treated is a hard tissue such as a uterine ligament, the load on the treatment portion  2   e  becomes large. This case is equivalent to increase in the value of the resistor R 1  of the ultrasound transducer  2   f,  and the current I 2  which is diverted to the non-inductive resistor R 2  increases, whereas the current I 1  which flows into the resistor R 1  decreases. 
     When the site to be treated is a hard tissue such as a uterine ligament, there arises the problem that the main apparatus  3  cannot output ultrasound since the stress increase and the load of the ultrasound probe are large. However, since when the site to be treated is a hard tissue such as a uterine ligament like this, the current I 1  which flows into the resistor R 1  decreases, the amplitude value of the treatment portion  2   e  decreases, and inability of the main apparatus  3  to output ultrasound due to large stress increase and load of the ultrasound probe can be suppressed. 
     As above, in the ultrasound operation system  1  of the present embodiment, the non-inductive resistor R 2  is provided in parallel between the output transformer Tr of the main apparatus  3  and the ultrasound transducer  2   f  in the hand piece  2 , whereby the current which is supplied to the ultrasound transducer  2   f  from the main apparatus  3  is diverted. Whereby, when the load on the treatment portion  2   e  becomes large, the current which flows into the non-inductive resistor R 2  increases, and the current which flows into the ultrasound transducer  2   f  decreases. Further, when the load on the treatment portion  2   e  becomes small, the current which flows into the non-inductive resistor R 2  decreases, and the current which flows into the ultrasound transducer  2   f  increases, 
     As a result, when the load on the treatment portion  2   e  becomes large, the ultrasound operation system  1  decreases the amplitude value of the treatment portion  2   e,  whereas when the load on the treatment portion  2   e  becomes small, the ultrasound operation system  1  can increase the amplitude value of the treatment portion  2   e . More specifically, even when the load on the treatment portion  2   e  varies, the ultrasound operation system  1  can control the amplitude value of the treatment portion  2   e  so that the amplitude value is close to the central value. 
     As above, the ultrasound operation system  1  diverts the current which is outputted from the output transformer Tr, and can increase or decrease the current which flows into the ultrasound transducer  2   f  in accordance to the load on the treatment portion  2   e,  by the non-inductive resistor R 2  provided in the hand piece  2 . Whereby, the ultrasound operation system  1  can automatically regulate the amplitude value in accordance with the load on the treatment portion  2   e.    
     As a result, the ultrasound operation system  1  of the present embodiment does not need to provide a control program and a control section for feedback in the main apparatus, does not need to feed back impedance from the ultrasound transducer, and perform feedback control of controlling the current which flows into the ultrasound transducer. 
     Consequently, according to the ultrasound operation system  1  of the present embodiment, the current which flows into the ultrasound transducer can be controlled without the need for the control program and the control section for performing feedback control. 
     The present invention is not limited to the aforementioned embodiment, and various changes, modifications and the like can be made within the range without departing from the gist of the present invention.