An ultrasonic surgical tool capable of vibrating in a plurality of modes and a drive system that provides non-linear vibration of the tool tip

Abstract

Ultrasonic surgery with a tip capable of vibrating in multiple modes simultaneously We provide a tool system for An ultrasonic surgical tool system includes a tip capable of vibrating simultaneously in multiple modes. The system includes a console capable of applying a drive signal to the tip, the drive signal including multiple components. Each component has a frequency characteristic based in part on an equivalent current flowing through a mechanical element in the tip. Each frequency component is distinct from the others. Upon application of the drive signal, the tip undergoes nonlinear vibration.

Description

Technical Field

[0001] This application generally relates to an ultrasonic-driven surgical handpiece. More specifically , the present invention relates to an ultrasonic-driven handpiece having a plurality of vibration modes and a method of driving the handpiece such that the tip head vibrates non-linearly.

Background Art

[0002] Ultrasonic surgical instruments are useful for performing several medical and surgical procedures. Generally, an ultrasonic surgical tool comprises a handpiece that includes at least one piezoelectric driver. The tip extends forward from a housing or shell in which the driver is disposed and is mechanically coupled to the driver. The tip has a head, which is provided with a mechanism (often teeth) sized to perform a particular medical or surgical operation. The ultrasonic tool system also includes a control console. The control console supplies an AC drive signal to the driver. When a drive signal is applied to the driver, the driver expands and contracts periodically. The expansion and contraction of the driver causes a similar movement within the tip, and more specifically within the head of the tip. When the tip moves in this manner, the tip is considered to be vibrating. The head vibrating at the tip is applied to tissue to perform a particular surgical or medical operation. For example, some tip heads are applied to hard tissue. One form of hard tissue is bone. When this type of tip head vibrates, the teeth at the tip vibrate back and forth to saw, i.e., remove, adjacent hard tissue. Still other tip heads are designed to be applied to soft tissue. Also, some ultrasonic tools are for tissue and surrounding ​ Remove the tissue by inducing cavitation in the body fluid. As a result of the tip head moving back and forth, cavitation occurs. Specifically, as a result of these vibrations, small voids, that is, cavities, are formed in the tissue and the surrounding body fluid. These voids are very low-pressure, small regions. A pressure difference occurs between the cells forming the tissue and these cavities. Since this pressure difference is relatively large, the cell wall ruptures. Due to the rupture of the cell wall, the cells forming the tissue are removed, that is, excised.

[0003] The heads of ultrasonic tips are often relatively small. Some heads have a diameter of less than 1.0 cm. Basically, an ultrasonic tool removes the tissue adjacent to the location where the head is applied. Since the surface area of the head is relatively small, ultrasonic handpieces have been found to be useful tools for accurately removing both hard and soft tissues.

[0004] Most tips are designed such that when a drive signal is applied, the tip head vibrates in a single mode. Here, the vibration mode should be understood as the movement path along which the tip head moves. Most of the tip is designed to vibrate linearly. This means that the head reciprocates along an axis. This axis basically coincides with the longitudinal axis from proximal to distal along the tip. Some tips are designed to vibrate in a torsional vibration or rotational vibration when vibrating. This means that when the head is activated and enters a vibrating state, it rotates around the longitudinal axis of the tip. Another tip is designed to be able to flex. This means that when the tip is activated, the longitudinal axis of the tip bends back and forth. This means that as the tip bends, i.e., flexes, the tip head moves.

[0005] Problems can occur if the tip head vibrates only longitudinally. This is because the movement of this type of tip head frequently induces cavitation within the tissue along the tip shaft. This can be a problem when the tip is used to remove hard tissue, i.e., bone, that is very close to soft tissue that should not be removed. The types of soft tissue that should not be removed include both blood vessels and tissue that is part of the nervous system. As a result of cavitation, unwanted removal of this soft tissue can occur, thus causing such problems.

[0006] Currently, tips are available that reduce this unwanted cavitation. These tips are designed to vibrate in two modes. The tip vibrates longitudinally. Also, the tip vibrates such that it twists about the longitudinal axis of the tip shaft. One such tip is the Long Micro Claw tip, commercially available from Stryker Corporation, Kalamazoo, Michigan, the applicant for this application. The structure of this tip is disclosed in U.S. Patent No. 6,955,680, "COUPLING VIBRATION ULTRASONIC HAND PIECE", the contents of which are hereby incorporated by reference to be clearly part of this specification.

[0007] When a drive signal is applied to a tip that can vibrate in different modes, the tip head undergoes a motion that is the sum of the vibratory displacements. When driven, it vibrates simultaneously in the longitudinal and torsional directions. The tip head that can vibrate vibrates simultaneously in the longitudinal direction and the rotational direction. Figure 1 shows this motion at a point on the tip head portion. As a result of these simultaneous vibrations, a point on the tip head portion reciprocates along a part of a helix. Therefore, this motion is along the proximal and distal sides of the longitudinal axis of the head and rotates around the longitudinal axis.

[0008] The advantage of vibrating the tip in this way is that the range in which the tip shaft vibrates in the longitudinal direction is small becomes. As a result, unwanted removal of the tissue adjacent to the shaft is similarly reduced.

[0009] The ultrasonic tool system described above is useful, but it is not without drawbacks. One dis advantage is that for this system to function, the two vibration modes must occur at the same frequency not. This requires the tip to be specially designed to vibrate in this mode become necessary. This limits the size and shape of the tip. This is a To perform a particular tissue removal technique, it is difficult to provide a tip that can be applied to the site There is a possibility. Furthermore, if the tip has to be designed to meet this requirement In some cases, it may be relatively expensive to manufacture the tip.

[0010] Furthermore, when the tip head undergoes this type of motion, the individual teeth of the tip head move reciprocally in a part of the helix This motion extends over a track usually less than 300 microns in length In fact, the motion of a single tooth is along a line oblique to the longitudinal axis of the tip shaft is. When an individual tooth cuts into the bone, the tooth forms a groove oblique to this axis. In the groove, the tooth When it reciprocates, the tip receives a resistance that hinders the movement of the head in directions other than the direction of the groove. Since each tooth moves within each groove, this resistance can be quite large. This hinders the operator's ability to direct, i.e., position, the tip in the desired direction.

[0011] Furthermore, as a result of any resection operation, the resected material forms debris in the vicinity of the tool performing the resection. This applies to the situation where an ultrasonic surgical tool is used to remove tissue. When the teeth of the ultrasonic surgical tool reciprocate in a linear movement path, debris tends to accumulate between the teeth. Such accumulation of debris has an adverse effect on the ability of the teeth to penetrate and remove tissue. SUMMARY OF THE INVENTION

[0012] The present invention relates to a novel and useful ultrasonic surgical tool system. The system of the present invention comprises a tip that vibrates in multiple modes during vibration. The system of the present invention further has a drive system that applies a drive signal to the tip to move the tip head along a non-linear travel path during vibration.

[0013] The system of the present invention typically has a drive system capable of providing a superimposed drive signal. This superimposed drive signal is the sum of a plurality of different components. Usually, the drive signal has one component for each vibration mode of the tip. In many versions of the present invention, each component has a frequency characteristic. This frequency characteristic is a frequency that is at or near the target frequency of a particular vibration mode of the tip. Here, the vibration mode can be the vibration of the tip in a single plane in the longitudinal, torsional or telescopic direction. Usually, different vibration modes ​​​​​​​​​ The frequencies of the holes are different from each other. Alternatively, the vibration mode can be vibration that occurs simultaneously in two or more planes. Here, the target frequency is any frequency between the resonance frequency and the anti-resonance frequency of the tip, which is within the frequency range for the specific frequency range in which the tip will vibrate.

[0014] A further feature of the present invention is to change the characteristics, namely the frequency and voltage, of each component of the drive signal. During the use of the ultrasonic tool, the tip head is subject to resistance, i.e., mechanical load, so these characteristics change. Due to this load, the equivalent impedance of the mechanical elements of the handpiece changes. This change in characteristics in the handpiece changes how, i.e., how the tip head vibrates, in response to the application of the drive signal. To ensure that the tip head is involved in the movement desired by the operator, the system of the present invention adjusts the drive signal. This adjustment of the drive signal is performed by adjusting the characteristics of the components of the drive signal.

[0015] The present invention is shown in detail in the claims. The above features and advantages of the present invention, as well as other features and advantages, will be further understood from the following detailed description taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0016]

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[0017] [I. Overview of the System and Hardware] Referring to Figures 2 and 3, an ultrasonic tool system 30 with the mechanism of the present invention is comprehensively will be described. System 30 includes a handpiece 32. The distal end portion 142 is attached to the handpiece 32 and extends forward distally from the handpiece 32. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142. (It should be understood that "distal" means away from the operator toward the site where the handpiece is applied. "Proximal" should be understood to mean the side of the operator having the handpiece, i.e., away from the site where the handpiece is applied). The distal end portion 142 is an element within the system 30 that is applied to tissue to perform a desired medical or surgical procedure. Also, the system 30 includes a control console 240. The control console 240 supplies a drive signal applied to the handpiece 32. In response to the application of the drive signal, the handpiece 32 vibrates the distal end portion 142.

[0018] The handpiece 32 includes a body or shell 34 shown only in FIG. 2. As can be seen from FIGS. 3 and 4, one or more vibrating piezoelectric drivers 36 (four are shown) are disposed within the shell 34. Each driver 36 is formed of a material that undergoes instantaneous expansion or contraction when an electric current is applied to the driver. These expansions and contractions occur along the longitudinal axis of the driver 36. This axis extends between the proximal and distal faces of the driver. The handpiece 32 includes a body or shell 34 shown only in FIG. 2. As can be seen from FIGS. 3 and 4, one or more vibrating piezoelectric drivers 36 (four are shown) are disposed within the shell 34. Each driver 36 is formed of a material that undergoes instantaneous expansion or contraction when an electric current is applied to the driver. These expansions and contractions occur along the longitudinal axis of the driver 36. This axis extends between the proximal and distal faces of the driver. The handpiece 32 includes a body or shell 34 shown only in FIG. 2. As can be seen from FIGS. 3 and 4, one or more vibrating piezoelectric drivers 36 (four are shown) are disposed within the shell 34. Each driver 36 is formed of a material that undergoes instantaneous expansion or contraction when an electric current is applied to the driver. These expansions and contractions occur along the longitudinal axis of the driver 36. This axis extends between the proximal and distal faces of the driver. The handpiece 32 includes a body or shell 34 shown only in FIG. 2. As can be seen from FIGS. 3 and 4, one or more vibrating piezoelectric drivers 36 (four are shown) are disposed within the shell 34. Each driver 36 is formed of a material that undergoes instantaneous expansion or contraction when an electric current is applied to the driver. These expansions and contractions occur along the longitudinal axis of the driver 36. This axis extends between the proximal and distal faces of the driver. The handpiece 32 includes a body or shell 34 shown only in FIG. 2. As can be seen from FIGS. 3 and 4, one or more vibrating piezoelectric drivers 36 (four are shown) are disposed within the shell 34. Each driver 36 is formed of a material that undergoes instantaneous expansion or contraction when an electric current is applied to the driver. These expansions and contractions occur along the longitudinal axis of the driver 36. This axis extends between the proximal and distal faces of the driver. A pair of leads 38 extends away from each driver 36. The leads 38 are attached to the opposing proximal and distal faces of the driver. Most, but not all, handpieces 32 include disk-shaped drivers 36. The drivers 36 are arranged in a stack with their ends connected. The leads 38 are through which the drive signal is applied to the driver. A pair of leads 38 extends away from each driver 36. The leads 38 are attached to the opposing proximal and distal faces of the driver. Most, but not all, handpieces 32 include disk-shaped drivers 36. The drivers 36 are arranged in a stack with their ends connected. The leads 38 are through which the drive signal is applied to the driver. A pair of leads 38 extends away from each driver 36. The leads 38 are attached to the opposing proximal and distal faces of the driver. Most, but not all, handpieces 32 include disk-shaped drivers 36. The drivers 36 are arranged in a stack with their ends connected. The leads 38 are through which the drive signal is applied to the driver. A pair of leads 38 extends away from each driver 36. The leads 38 are attached to the opposing proximal and distal faces of the driver. Most, but not all, handpieces 32 include disk-shaped drivers 36. The drivers 36 are arranged in a stack with their ends connected. The leads 38 are through which the drive signal is applied to the driver. It is an element of the system 30 applied to the bar 36. An insulating disk 40 shown is disposed between adjacent drivers. In FIG. 2, the driver 36 and the insulating disk 40 are shown as being spaced apart from each other. This is to facilitate the illustration of the elements. Actually, the driver 36 and the insulating disk 40 are in contact without a gap.

[0019] The post 44 extends longitudinally through the driver 36, the lead 38, and the insulating disk. The post 44 passes through the driver 36, the lead 38, and the insulating disk 40 and extends along the longitudinal axis that forms the same straight line of these elements. Although the through holes inside the driver 36, the lead 38, and the insulating disk are not visible, the post 44 extends through the through holes. The post 44 projects outward from both the driver 36 located on the most proximal side and the driver located on the most distal side.

[0020] The proximal end mass 46 is located adjacent to and in contact with the proximal side surface of the driver 36 located most proximally. The mass 46 is attached to the proximal end portion of the post 44. When the post 44 is threaded, the mass 36 can be a nut.

[0021] The horn 48 shown only in FIG. 3 extends forward from the distal side surface of the driver 36 located most distally. The horn 48 has a base having a diameter approximately equal to the diameter of the driver 36. As it extends forward from the driver 36 towards the distal side, the diameter of the horn 48 decreases. The exposed distal end surface of the post 44 is fixed to the horn 48. In many versions of the present invention, the post 44 and the horn 48 are an integrally formed unit. Hand ​​​​​​​​​​ The piece 32 is configured such that a stack of the driver 36 and the insulating disks is compressed between the proximal end mass 36 and the horn 48 and the like.

[0022] A handpiece memory 56 is also disposed within the handpiece shell 34. The memory 5 6 contains data used to control the operation of the handpiece 32 and the distal end portion 142 . The memory 56 can take the form of an EPROM, an EEPROM, or an RFID tag . The structure of the memory is not part of the present invention. For illustrative purposes, the handpiece memory 56 is an RF ID tag. A coil 54 connected to the memory 56 is shown. The coil 54 is an element associated with the handpiece through which the control console 240 reads from and writes to the handpiece memory 56 .

[0023] FIG. 5 shows the types of data stored in the handpiece memory 56. These data include data identifying the handpiece 32, as represented by the field 62 . These data are useful for verifying that the console 240 can apply a drive signal to the handpiece. The data within the field 62 can also indicate the type of information regarding the handpiece presented on the console display 278. Other data within the handpiece memory 56 are used to control the supply of the drive signal to the driver 36 . The use of these data will be described later, but here, the types of data are described. The field 64 contains data indicating the capacitance C , that is, the capacitance of the stack of the driver 36 . The driver capacitance is analyzed during the assembly process of the handpiece 34 . O It can be obtained by. In many cases, the sum of the capacitances of the drivers is 50 0 pF to 5000 pF. Field 66 contains data regarding the maximum current to be applied to the handpiece 36, that is current

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[0024] Also, in the handpiece memory 56, data indicating the minimum frequency and the maximum frequency of the drive signal to be applied to the handpiece 32 is stored. The minimum frequency stored in field 72 is usually the minimum frequency of the drive signal that can be supplied by the control console . The maximum frequency of the drive signal stored in field 74 is usually 5 kHz to higher than the minimum frequency . . The maximum frequency of the drive signal stored in field 74 is usually 5 kHz to 40 kHz is high.

[0025] Field 76 includes coefficients for filtering the control signals output from the controller 96. To determine the respective final levels of these signals, a PID control loop is used. Field 76 includes coefficients for each of these control loops. The data within fields 62, 66, 68, 70, 72, 74, and 76 is stored in the handpiece memory 56 as part of the handpiece assembly process, similar to the data within field 64. It should be understood.

[0026] Also, the handpiece memory 56 also includes a field 78 as a usage history field. The control console 240 writes data to field 128 to provide a log of the operation of the handpiece during use of the handpiece 32.

[0027] Returning to FIG. 4, it can be seen that two conductors 132 are also shown inside the handpiece 32. The conductors 132 extend from the coil 54 to the distal end of the handpiece. Conductor 1 32 is also connected to a coil 134, which is a second coil disposed within the handpiece 32.

[0028] The tip 142 extends forward from the horn 48 of the handpiece. The tip 142 has a generally cylindrical shaft 144. Although not in all of the present invention, in some bar geons, the shaft 144 has a plurality of portions each having a different cross-sectional diameter. In the illustrated version of the present invention, the shaft 144 of the tip has a proximal portion 146. The shaft proximal portion 146 removably couples the tip to the handpiece 32. In one version of the invention, a coupling mechanism is formed that is designed to facilitate The handpiece coupling mechanism is a boss 49 extending forwardly from the horn 48 . The boss 49 has an outer surface formed with threads (not shown). A closed end bore 144 extends inwardly from the proximal end of shaft 144 partially through distal portion 145. 45. The hole 145 accommodates a threaded boss that is integral with the handpiece horn 48. The nut is provided with threads (not shown) designed to engage with the nut.

[0029] In the illustrated version of the invention, shaft 144 extends from shaft proximal portion 146 to The proximal portion 146 has a forwardly extending central portion 150. The central portion 150 has a diameter smaller than that of the proximal portion 146. The shaft 144 shown has a distal portion 156. Portion 156 has a diameter smaller than the diameter of central portion 150 .

[0030] The head 158 is the distal-most portion of the tip 142. The head 158 is located proximal to the shaft. The head 158 is located adjacent and forward of the distal end portion 156. The head 158 may have teeth or grooves. The distal head 158 is assembled to perform the desired procedure. The teeth or grooves are the portion of the system 30 that is pressed against the weave. These teeth or grooves are designed to compress tissue. As a result of the head moving, The teeth or grooves remove the tissue. The geometry of the tip teeth or grooves is not part of the present invention.

[0031] The handpiece 32 generally has a tip 142 that vibrates in a similar manner as the driver reciprocates. The shaft is designed to induce a dynamic movement along the longitudinal axis of the tip, more specifically along the shaft. In terms of moving back and forth along the shaft, these reciprocating motions are longitudinal vibrations. This invention further provides a mechanism at the tip for changing the proximal-to-distal vibration applied to the proximal end of the shaft into at least two different types of vibrations. In the illustrated tip 142, these mechanisms are spiral grooves 15 extending inward from the outer surface of the central portion 150 of the shaft. 2. Due to the presence of the groove 152, a part of the longitudinal motion applied to the proximal portion of the shaft becomes a motion that vibrates the tip portion in front of the groove not only longitudinally but also rotationally while vibrating. It should be understood that the rotational vibration means that the shaft and the tip vibrate within an arc extending around the longitudinal axis of the shaft 144.

[0032] The tip 142 incorporated into the system 30 of the present invention is further designed such that the resonance frequencies of a plurality of vibration modes are different. In many cases, these resonance frequencies are spaced from each other by an interval of 200 Hz to 2000 Hz.

[0033] The sleeve 170 is disposed around the tip shaft 144. The sleeve 170 is formed of plastic material. At the proximal end of the sleeve, a mechanism is formed to facilitate detachably connecting the sleeve to the distal end of the handpiece horn 48. The elements forming the system 30 are such that the sleeve is formed to be radially spaced from the tip shaft 144 and longitudinally spaced from the tip head 160. More specifically, this element is dimensioned such that the tip does not contact the sleeve during normal vibration of the tip portion.

[0034] Although not part of the present invention, the sleeve 170 often has connecting parts (fittings) 17 ​​​​It can be seen that 2 is formed. The connecting part 172 is formed to receive the perfusion line. During the use of the system 30, in many cases, the perfusion fluid is poured into the sleeve 170. The fluid flows through the gap between the tip 142 and the sleeve 170 and flows out from the open distal end of the sleeve. Continuous holes are formed in the handpiece post 44 and the tip 142 (the holes are not shown). During the procedure, suction is performed through these holes. By suction, the perfusion fluid and the debris formed by the procedure and mixed in the fluid are sucked out from the site where the tip head 158 is applied. Also, by suction, the tissue is sucked out toward the tip head 158. By sucking out the tissue toward the tip head 158 in this way, the resection of the tissue by the tip head is promoted. The tip memory 184 shown as a dashed rectangle in FIG. 3 is disposed within the sleeve. Although this memory is disposed within the sleeve 170, since the memory is used to control the operation of the tip 142, it is called the tip memory. Furthermore, the tip 142 and the sleeve 170 usually circulate together as a single package. The tip 142 is usually first coupled to the handpiece 32. After the tip 142 is disposed at a predetermined position, the sleeve 170 is fitted into the handpiece.

[0035] The tip memory 184 is usually the same type of memory as the handpiece memory 56. Therefore, in the illustrated version of the present invention, the tip memory 184 is an RFID tag. The coil 182 shown only in FIG. 4 and embedded in the sleeve 170 is the input pin of the tip memory 172. is connected to. The elements forming the system 30 are such that when the sleeve 170 is fitted into the handpiece 32, the handpiece coil 134 and the coil 182 can be involved in inductive signal exchange. As represented by the field 188, these data include a tip identification information field. The data in the field 188 identifies the tip and is similar to the data identifying the handpiece in the handpiece identification information field 112 of the handpiece memory. In the field 190,

[0036] Figure 6 shows the types of data included in the tip memory 184. is stored data indicating the maximum equivalent current flowing through the mechanical elements of the handpiece. This concept will be explained later. The field 191 stores data indicating the maximum potential for the first component of the drive signal

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[0037] Field 206 contains data that defines the minimum frequency of the second component of the drive signal. Field 208 contains data that defines the maximum frequency of the second component of the drive signal. Field 210 contains data that defines the target frequency ω for the second component of the drive signal. TRGT2 Field 212 contains the virtual impedance coefficient m2 used in association with the target frequency for the second component of the drive signal.

[0038] The PID coefficient field 216 contains filtering coefficients for the control signal that may be more detailed than the data in the PID coefficient field 76 of the handpiece memory for the tip. Also, the tip memory 184 also includes a tip usage history field 218. During the operation of the system 30, the control console 240 writes data to the field 218 regarding the use of the tip 142.

[0039] Next, the control console 240 described with respect to FIGS. 2, 4, and 7 supplies a drive signal to the handpiece 32, as a result of which the tip 142 vibrates. These elements include a power supply 2 42. The power supply 242 outputs a constant voltage signal of typically DC1V to DC250V. In many versions of the invention, the maximum potential of the voltage output from the power supply 242 is DC150 V or less. The voltage generated by the power supply 242 is applied to the variable gain amplifier 244 . A control signal, specifically, the WAVEFORM_SET (W_S) signal, is applied to the amplifier 244 . The WAVEFORM_SET signal determines the gain of the signal generated by the amplifier . In many versions of the invention, the amplifier 244 is a variable gain class-A amplifier that can output an AC signal in response to the WAVEFORM_SE T signal. More specifically , the amplifier 244 can output a signal having a frequency of 10 kHz to 100 kHz . In many cases, the signal has a minimum frequency of 20 kHz

[0040] The output signal from the amplifier 244 is applied to the primary winding 254 of the transformer 2 48, which is also part of the same control console 240. The voltage present across the secondary winding 258 of the transformer 248 is the drive signal applied to the handpiece driver 36 . This voltage is typically at most 1500 volts AC peak. The drive signal is applied in parallel across both ends of the driver 36 .

[0041] The transformer 248 includes a tickler coil 256. The voltage present across both ends of the tickler coil 256 is applied to the voltage measurement circuit 262 . Based on the signal across both ends of the tickler coil 256, the circuit 262 generates a signal representing the potential and phase of the voltage V , that is, the voltage of the drive signal applied to the handpiece 32 S . A coil 264, also disposed within the control console 72, is very close to one of the conductors extending from the secondary winding 258 of the transformer . ​is located. The signals at both ends of the coil 264 are applied to the current measurement circuit 266. Circuit 2 66 generates a signal representing the current i S , that is, the magnitude and phase of the current of the drive signal flowing through the handpiece .

[0042] The drive signal existing at both ends of the secondary winding 258 of the transformer is present in two conductive contacts 266 attached to a socket (not shown) integrated with the control console .

[0043] The drive signal is applied to the handpiece driver by the cable 230 that is only seen in FIG. 1. In many configurations of the system 30, the handpiece 30 and the cable 23 0 are a single unit. The cable 230 is connected to the control console socket where the contact 266 is located.

[0044] In the version of the present invention where the handpiece 32 and the cable 230 are a single unit , the handpiece coil 54 is disposed within a plug integrated with the cable. A complementary coil 268 is disposed within the console socket. The elements forming the system are configured such that when the plug integrated with the cable 2 30 is inserted into the handpiece socket, the coils 54 and 2 68 can exchange signals by induction.

[0045] The drive signal voltage V S and the signal representing the current i S are supplied to the handpiece driver 36 and also applied to the processor 276 that is also inside the control console 240. The control console 240 also includes a memory reader 272. One end of the memory reader 272 is connected to the con ​One end is connected to the sole coil 268 and the other end is connected to the processor 276. Memory reader 2 72 converts the signals existing at both ends of the coil 268 into data signals that can be read by the processor 272 . Also, the memory reader 272 outputs a signal applied to the coil 268 according to the signal output from the processor 272, and by this signal, the coil outputs a signal and as a result, data is written into the handpiece memory 56 and the tip memory 184 . The structure of the memory reader 268 complements the handpiece memory 102 . Therefore, the memory reader can be an assembly (means, functional unit, component, device) that can read data in an EPROM or EEPROM , or can be an assembly that can call an RFID and read data therefrom .

[0046] The processor 272 generates a WAVEFORM_SET signal applied to the amplifier 244 . In this way, the processor 276 sets the characteristics of the drive signal output from the control console 240 and applied to the handpiece 32 . The characteristics of the drive signal set by the processor 276 are the voltage and frequency of the drive signal . The processor 276 determines these characteristics according to the characteristics of the handpiece 32 and the tip 134 . Also, the processor 96 determines the drive signal according to the captured measurement values of the voltage V S and the current i S .

[0047] The display 278 is incorporated in the control console 240. Display 27 ​​​The image on 8 is shown as being generated by processor 276. The display 27 The information displayed on 8 includes information identifying the handpiece 32 and the tip, and information describing the characteristics of the operating state of the system The display 278 is often a touchscreen display. Buttons are presented on the display by processor 272 By pressing those buttons, the operator can set what he desires as the specific operating characteristics of the system 30.

[0048] In addition to the buttons presented on the display 278, there is usually at least one on / off switch associated with the control console In FIGS. 2 and 7, this on / off switch is represented by footswitch 280. The footswitch 280 is configured to generate a signal that varies according to the degree to which the switch is depressed. That signal is supplied to processor 280. Based on the state of the signal supplied by footswitch 280 the processor 276 adjusts the generation of the drive signal to control both whether the tip vibrates and the magnitude of the vibration of the tip head

[0049] [II. Basic Operations] The system 30 of the present invention is designed such that the control console 240 outputs a drive signal that causes the tip head 158 to move along a movement path that can be regarded as non-linear as a result In the context of the present invention, a non-linear travel path is a travel path such that when the tip head 158 vibrates back and forth the movement of a single point of the head follows two different sets of points in space as if. The tip head, relative to the starting point, has an outbound of a single motion cycle ​​​ When participating in the outbound phase, the tip head travels along a first set of points. . For the tip head to return to the starting point during the inbound phase of the same cycle When participating in, the tip head travels along a second set of points that is different from the first set of points. . Furthermore, the set of points that the tip head travels along during the first complete oscillation cycle may be different from the set of points that the tip head travels along in the next oscillation cycle. During the oscillation cycle, it should be understood that the set of points that the tip head travels along may not lie in a single plane. The set of points may be in multiple planes. In other words, the set of points can rotate around one or more axes. cycle. During the oscillation cycle, the set of points that the tip head travels along may not lie in a single plane. It should be understood that the set of points may be in multiple planes. In other words, the set of points can rotate around one or more axes. The set of points along which the tip head travels may not be in a single plane. It should be understood. The set of points may be in multiple planes. In other words, the set of points can rotate around one or more axes. The set of points can rotate around one or more axes.

[0050] FIG. 8 shows the waveform of the drive signal that the control console 240 outputs to the handpiece driver 36 to induce the above-described movement of the tip head 158. The drive signal is the sum of two AC signals, which are here called drive signal components. Each drive signal component has its own frequency and its own potential. Usually, the frequencies of these different components are different. Also, in many cases, the potentials of the different components of the drive signal are different from each other. The drive signal is the sum of two AC signals, which are here called drive signal components. Each drive signal component has its own frequency and its own potential. Usually, the frequencies of these different components are different. Also, in many cases, the potentials of the different components of the drive signal are different from each other. The drive signal is the sum of two AC signals, which are here called drive signal components. Each drive signal component has its own frequency and its own potential. Usually, the frequencies of these different components are different. Also, in many cases, the potentials of the different components of the drive signal are different from each other. potential. Usually, the frequencies of these different components are different. Also, in many cases, the potentials of the different components of the drive signal are different from each other. The drive signal is the sum of two AC signals, which are here called drive signal components. Each drive signal component has its own frequency and its own potential. Usually, the frequencies of these different components are different. Also, in many cases, the potentials of the different components of the drive signal are different from each other.

[0051] A further feature of many versions of the present invention is that each component of the drive signal is at or near the target frequency of a particular vibration mode of the tip. The system 30 can be configured such that the vibration mode is a vibration of the tip in a single plane in the longitudinal, torsional, or telescopic direction. Here, it should be understood that the vibration in the longitudinal plane is a reciprocating motion along the longitudinal axis of the tip 142. The vibration in the torsional plane is the tip head A further feature of many versions of the present invention is that each component of the drive signal is at or near the target frequency of a particular vibration mode of the tip. The system 30 can be configured such that the vibration mode is a vibration of the tip in a single plane in the longitudinal, torsional, or telescopic direction. Here, it should be understood that the vibration in the longitudinal plane is a reciprocating motion along the longitudinal axis of the tip 142. The vibration in the torsional plane is the tip head A further feature of many versions of the present invention is that each component of the drive signal is at or near the target frequency of a particular vibration mode of the tip. The system 30 can be configured such that the vibration mode is a vibration of the tip in a single plane in the longitudinal, torsional, or telescopic direction. Here, it should be understood that the vibration in the longitudinal plane is a reciprocating motion along the longitudinal axis of the tip 142. The vibration in the torsional plane is the tip head A further feature of many versions of the present invention is that each component of the drive signal is at or near the target frequency of a particular vibration mode of the tip. The system 30 can be configured such that the vibration mode is a vibration of the tip in a single plane in the longitudinal, torsional, or telescopic direction. Here, it should be understood that the vibration in the longitudinal plane is a reciprocating motion along the longitudinal axis of the tip 142. The vibration in the torsional plane is the tip head It should be understood that the vibration in the longitudinal plane is a reciprocating motion along the longitudinal axis of the tip 142. The vibration in the torsional plane is the tip head It is understood to be the reciprocating rotational motion of the tip head 158 in a plane perpendicular to the longitudinal axis of . The bending motion is the reciprocating motion of the tip head in the plane in which the longitudinal axis of the tip is arranged . Therefore, the bending motion is the deflection of the tip around the shaft 144. This bending motion may occur in any direction of 360 degrees around the shaft. Alternatively, the vibration mode of the tip portion 42 can be a vibration that is the simultaneous reciprocating motion of the tip portions in two planes . For example, one vibration mode can be such that the movement is along a first line that intersects the longitudinal axis of the tip shaft , and can be in the longitudinal and torsional directions. The second mode can be the second combined longitudinal and torsional direction of motion along one line. The difference between these two vibration modes is that the vibration of the second mode is along a line different from the line of the vibration of the first mode.

[0052] The "target frequency" for the vibration mode according to the present invention is a frequency within the range in which the tip portion 142 vibrates . The target frequency is usually one of the resonance frequency for the vibration mode, the anti-resonance frequency for the vibration mode , or a frequency between the resonance frequency and the anti-resonance frequency. Since the resonance frequencies of the vibration modes of the tip portion are different from each other, the target frequencies of the vibration modes are also understood to be different.

[0053] In many versions of the present invention, the potential of each component of the drive signal promotes the flow of a target equivalent current through what is known as the mechanical elements of the handpiece 32 and the tip portion 142. These elements include the driver 36, the post 44, and the proximal . It includes a tip mass 46, a horn 48, and a tip portion 152. The sleeve 170 is not normally considered an element through which an equivalent current flows. This is because when the sleeve 170 vibrates, the vibration of the sleeve is due to the vibration of other elements. To simplify further explanation, this will be simply referred to as the equivalent current flowing through the mechanical elements of the handpiece. This terminology will be used even when the shell 170 can be regarded as a mechanical element of the handpiece 32.

[0054] Figure 9A is a schematic diagram showing how the drive signal current i S is divided into two components. The first component is the current i which is, that is, the current flowing through the handpiece driver 36. O The second component is the current i which is, that is, the equivalent M current flowing through the mechanical elements of the handpiece. According to Ohm's law, the current flowing through the driver and the equivalent current flowing through the mechanical elements of the handpiece are functions of the drive signal voltage V and the impedance of these elements. In Figure 9A, Z S is the impedance of the handpiece driver 36. The impedance Z O is the equivalent reactance of the mechanical elements of the handpiece. The impedance Z M is the equivalent reactance of the mechanical elements of the handpiece.

[0055] The impedance of the driver 36 is mainly due to its capacitive reactance. Therefore, in the schematic diagram of Figure 9B, the driver impedance Z O is simply represented as a function of the driver capacitor tance C O For the purpose of the system 30 of the present invention, the driver capaci tance C Ois generally constant. The equivalent impedance of the mechanical elements of the handpiece has a resistance component, an inductive reactance component, and a resistance component. Thus, in FIG. 9B , the mechanical equivalent impedance Z M is the resistance R M , the capacitance C M and the inductance L M expressed as a function of. In FIG. 9B, the mechanical equivalent resistance R M , the equivalent capacitance C M and the equivalent inductance L M are shown as variable. This is because these characteristics of the handpiece change according to the mechanical resistance to which the tip 142 is exposed when the tip is applied to the tissue .

[0056] At any given time, the equivalent current flowing through the mechanical elements of the handpiece is determined based on the following equation .

Equation

Number

[0057] As already mentioned, the system 30 of the present invention further configures the drive signal such that each component of the drive signal is at a frequency that closely follows as close as possible to the target frequency of the mechanical elements of the handpiece

[0058] Generally, the relationship between the frequency of the drive signal and the target frequency can be obtained by first obtaining the real component of the ratio of the current flowing through the handpiece driver 36 to the equivalent current flowing through the mechanical elements of the handpiece This ratio is represented by the following equation.

Number

[0059] Since the drive signal applied to the handpiece driver according to the present invention is composed of a plurality of components, the ratio in the case of a single component is as follows.

Number

[0060] This ratio is compared with a fixed target ratio (TR). The target ratio is usually a number between 0 and 1, including 0 and 1. When it is desired that the component of the drive signal be at the resonance frequency of the vibration mode, the target ratio is 0. When it is desired that the component of the drive signal be at the anti-resonance frequency of the vibration mode, the target ratio is 1. In embodiments of the present invention where the target frequency of the component of the drive signal is at a frequency between the resonance frequency and the anti-resonance frequency of the vibration mode, the drive frequency is a fraction between 0 and 1. When comparing the ratio of Equation (2A) with the target ratio alone, there may be situations where it does not give a good measure of the relationship between the frequency of the drive signal component and the desired target frequency. This can occur as a result of the placement of the tip head 158 relative to the tissue. More specifically,

[0061] some inherent characteristics of the tip heads are such that when the tip head is placed against the tissue and loaded, there are large variations in the equivalent reactance of the mechanical elements of the handpiece over the frequency range including the target frequency. Further, sometimes the operator may want to position the tip head 158 against the tissue before activating the handpiece 32. When this occurs, the resistive component of the equivalent impedance of the mechanical elements of the handpiece can be much larger than both the capacitive reactance and the inductive reactance of this component of the impedance. In either of these situations, the steps described later of changing the frequency of the drive signal component so that the ratio of Equation (2A) becomes closer to the target ratio are such that when the tip head is placed against the tissue and loaded, there are large variations in the equivalent reactance of the mechanical elements of the handpiece over the frequency range including the target frequency. Further, sometimes the operator may want to position the tip head 158 against the tissue before activating the handpiece 32. When this occurs, the resistive component of the equivalent impedance of the mechanical elements of the handpiece can be much larger than both the capacitive reactance and the inductive reactance of this component of the impedance. In either of these situations, the steps described later of changing the frequency of the drive signal component so that the ratio of Equation (2A) becomes closer to the target ratio are such that when the tip head is placed against the tissue and loaded, there are large variations in the equivalent reactance of the mechanical elements of the handpiece over the frequency range including the target frequency. Further, sometimes the operator may want to position the tip head 158 against the tissue before activating the handpiece 32. When this occurs, the resistive component of the equivalent impedance of the mechanical elements of the handpiece can be much larger than both the capacitive reactance and the inductive reactance of this component of the impedance. In either of these situations, the steps described later of changing the frequency of the drive signal component so that the ratio of Equation (2A) becomes closer to the target ratio are does not lead to supplying a drive signal having a component at a frequency close to the target frequency There may be cases.

[0062] Therefore, in order to determine whether the component of the drive signal is at a frequency close to the target frequency for the vibration mode to which the component is associated, the following modified version of Equation (2A) is used. [Number] In Equation (2B), the part on the right side of the plus sign is the actual frequency ω X of the component of the drive signal, and ω TRGT-X , that is, the difference from the desired target frequency for the component of the drive signal, and accordingly, changes the basic ratio. The exponent A exists because the change may be based on a difference of quadratic or higher order between the two frequencies . The coefficient m X is a coefficient that defines a gradient for defining the change of the ratio according to the difference between the actual frequency and the target frequency .

[0063] [III. Actual Operation] The operation of the system 30 of the present invention starts from connecting the tip 142 to the handpiece 32 . The sleeve 170 is fitted over the tip and also attached to the handpiece 32 . The cable 230 is attached to the control console 240. At that point, the console 240 is ready to be switched on. The above sub-steps constitute the initial assembly and startup of the system , that is, step 302 in FIG. 10A. When the control console 240 is first switched on, the processor 276 reads the data stored in the handpiece memory 56 and the tip memory 184 in step 304 . The p ​The processor 276 asserts an appropriate command to the memory reader 272 to receive this data.

[0064] Based on the read data, at step 306, the processor completes the initial configuration of the system. Step 306 includes performing several evaluations to determine whether the system 30 is appropriately configured for use. These evaluations include determining whether the handpiece is a handpiece to which the control console 240 can supply a drive signal, and determining whether the tip 142 is a tip operable by the handpiece. These evaluations can be based on the data in the handpiece identification information field 62 and the tip identification information field 188. Also, the processor 276 evaluates whether the handpiece 32 and the tip 142 are in a state of being used, based on the data read from the handpiece usage history field 78 and the tip usage history field 218. An example of data indicating that it may not be suitable for use

[0065] is data indicating that a particular element, namely the handpiece or tip, has been used for a number of times or for a total time exceeding the designed product life of that element. If the element is considered to be appropriately assembled for use as . The above are all part of step 306. The reception of the operator's initial setting command is also part of step 306.

[0066] Based on the data in the handpiece memory 56 and the tip memory 184, and the command input by the operator, the processor 276, in step 308, determines the component of the drive signal for each mechanical element of the handpiece to be the selected maximum equivalent current i SELECTMA X-X . The main operation example of the system is based on the tip portion 142 of FIG. 3. Specifically, the tip portion 142 is designed such that the drive signal causes the movement of the tip heads 158 in two planes, namely the longitudinal direction and the bending direction. Therefore, the drive signal consists of two components . That is, the first component is based on the target frequency associated with the vibration in the longitudinal plane, and the second component is based on the target frequency associated with the vibration in the torsional plane. In step 308, the selected maximum equivalent current is determined for each component of the drive signal using the following equation.

Equation

Equation

Number

[0067] In the described version of the present invention, the drive signal has two components. Therefore, in step 308, equation (3) is executed twice. When the equation is first executed, the maximum equivalent current for the first drive signal component, i.e., the equivalent current of the maximum current field 192 equivalent current

Number

Number

Number

[0068] Step 310 is whether the processor has activated the control unit to instruct that the operator wants to operate the handpiece, i.e., wants to vibrate the tip head 158 Indicates waiting to make a determination. In the embodiment of the present invention to be described, the processor 2 76 monitors the signal output by the foot switch 280 to perform step 310. When the operator wants to activate the tip, the operator presses the foot switch 280 . The magnitude of the vibration of the tip head is set by the operator controlling the degree to which the foot switch 280 is pressed .

[0069] When the processor 276 receives a signal from the foot switch indicating that the switch has been pressed , the processor performs step 312. In step 312, the processor 2 72 determines the target equivalent current of each component of the drive signal

Number

Number

Number

[0070] When the console 240 first executes the control loop of FIGS. 10A-10D, that is, , at the first execution of the loop after the evaluation result of step 310 is positive, the processor 27 6 executes step 314. In step 314, the initial characteristics of the components of the drive signal are generated . The frequency of each component is called the variable FREQ_COMP-X. The voltage of each component is called the variable VOLTAGE_COMP-X. Each component of the drive signal has an initial frequency and an initial potential. The initial frequency of a certain component is the minimum frequency of the component, such as being read from the tip memory 158. For the first component, this is the frequency included in the memory field 196. For the second component, this is the frequency included in the memory field 206. The initial potential is a potential less than the maximum potential of the component of the drive signal. In some aspects of the present invention, the initial potential is 0.03 to 0.07 times the maximum potential for the component of the drive signal. [Number] For the first component of the drive signal, the potential of the tip memory field 19 1 is [Number] used as. When calculating the initial potential of the second component of the drive signal, the potential of the tip memory field 193 serves as [Number] .

[0071] Next, based on the characteristics of each component of the drive signal, the control console 240 proceeds to step 315 Outputs a drive signal. As part of step 315, the processor 276 generates a waveform representing the sum of two components of the drive signal. This waveform has the shape of the waveform shown in FIG. 8. The processor 276 generates a WAVEFORM_SET signal representing this waveform. Thereafter, the WAVEFORM_SET signal is applied to the input of the amplifier 244 to which the gain control signal is supplied.

[0072] In response to receiving the WAVEFORM_SET signal, the amplifier 244 selectively amplifies and attenuates the signal from the power supply 242 as part of step 315. The output signal of the amplifier is applied to the primary winding 254 of the transformer. The transformer 248 outputs a drive signal to the handpiece driver 36 through the cable 230. The above are all part of step 315.

[0073] In response to the drive signal being applied to the handpiece driver 36, the driver expands and contracts periodically. The expansion and contraction of the driver are proportional to the potential of the drive signal. The expansion and contraction are proportional to the amplitude of the drive signal and are at the frequency of the drive signal. The handpiece horn 48 amplifies these expansions and contractions and transmits them to the proximal portion 146. These vibrations are along the longitudinal plane of the distal portion. The groove 152 converts a part of the movement of this shaft into vibrations in the torsional plane. Due to these changing potentials of the vibrations and the structure of the distal portion, the distal head 158 is oriented to vibrate, and its movement is non-linear as shown in FIG. 11. In FIG. 11, immediately to the right of the leftmost equal sign, this movement is shown as a single elliptical travel path.

[0074] ​​​​​​​​​​​​​​In the present invention, since each component of the drive signal does not have the same frequency, two consecutive vibrations The paths of the cycles do not coincide. As a result, the tip head, in addition to being non-linear, receives vibrations whose directions change over time. The single elliptical loop in FIG. 11 does not actually form a closed loop. In FIG. 11, the central plot to the right of the equal sign in the center shows the path of a point on the tip head after the tip head has been involved in a plurality of vibration cycles. In FIG. 11, the plot at the right end of the equal sign shows the path of the tip head point after the tip head has been involved in even more vibration cycles . These plots show that over a certain period, a point on the tip head, i.e., a point on the tooth, subtends one surface . The surface in FIG. 11 originally appears curved, but it should be understood that the surface may curve around one or more axes . Implied in this movement of the tip head point is that the direction of the point's path changes in a continuous series of multiple vibration cycles.

[0075] System 30 is involved in a feedback control process to ensure that the output drive signal continues to bring about the desired movement of tip head 158 . To perform this control, in step 154, processor 272, in step 316, system 96 monitors the voltage V of the drive signal flowing through the handpiece . This is to monitor the output signal generated by voltage measurement circuit S 262 by processor 272. As part of this monitoring, the processor divides voltage V into a plurality of components. Specifically, voltage V S is divided into one component for each component that makes up the drive signal. In the aspect of the present invention being described S ​ The drive signal has two components. Therefore, the voltage V S is the potential of the first component

Number

Number

[0076] As part of the feedback control, at step 318, the processor 272 monitors the current i which is the drive signal current flowing through the handpiece. This monitoring is performed using the current measurement circuit S 266. Similar to the drive signal potential, the drive signal current consists of multiple components, one for each component of the drive signal. Therefore, as part of step 318, the processor divides the drive signal current into a first component characteristic current

Number

Number

Number

Number

[0077] In step 320, the processor determines the equivalent current for each component of the drive signal. Since this equivalent current is not measured but calculated, it is sometimes referred to as the calculated equivalent current. In step 320, using Equation (1A),

Number

Number

[0078] Calculated current

Number

Number

Number

Number

Number

Number

[0079] Equation (1A) has an additional variable for the handpiece driver 36, namely capacitance C0. The processor 272 utilizes, as this capacitance, the driver capacitance read from the handpiece memory field 64.

[0080] In step 322, the calculated equivalent current of the first component of the drive signal is compared with the target equivalent current of that component of the drive signal. This comparison is made because if the equivalent current is less than the target equivalent current, there is a high probability that the vibration in the associated vibration mode will not have an amplitude sufficient to promote the desired movement of the tip head 158. If the equivalent current applied to the mechanical elements of the handpiece is greater than the target equivalent current, the tip head 158 may be subjected to vibrations with an amplitude greater than that desired by the operator.

[0081] In some versions of the present invention, when the calculated equivalent current is within 10% of the target current, the equivalent current applied to the mechanical part of the handpiece promotes the desired vibration. Alternatively, when the two currents are within 5% of each other, ideally within 1% of each other, the current is of sufficient magnitude.

[0082] When the two equivalent currents are approximately equal, the system 30 The flowing equivalent current is at a level assumed to result in vibrations of an appropriate amplitude at the tip in the relevant vibration mode with the application of the drive signal at the correct frequency. When the system 30 is in this state, the processor 96 proceeds to step 326. head 52. If the system 30 is in this state, the processor 96 proceeds to step 326.

[0083] In many cases, the comparison in step 322 indicates that the calculated mechanical equivalent current

Number

Number

Number

[0084] In step 326, the processor 272 determines whether the frequency characteristics of the first component of the drive signal are at or approximately equal to the target frequency of the said component of the drive signal. This determination is made to ensure that, as a result of the frequency characteristics of the first component, the output of the drive signal promotes the desired movement of the tip head. In step 326, equation (2 is used. This determination is made based on the driver capacitance and the constant frequency characteristics of the drive signal. is used to ensure that the output of the drive signal promotes the desired movement of the tip head. In step 326, equation (2 This determination is made by comparing the ratio of (B) with a target ratio. The variables used in step 318 to generate the calculated equivalent current are used to generate this ratio. The remaining variables used to generate this ratio are the target values of the frequency components. This is the variable ω in field 202 of the tip memory 184. The coefficient m1 is from the coefficient field 204 of the tip memory 184. The exponent A is assumed to be constant and the same for all calculations that generate a ratio modifier (which changes the ratio). It is also within the scope of the present invention for the exponent TARGET1 A to be variable. The frequency characteristics are, in some cases, considered to be approximately equal to the target frequency characteristics when the ratio is within 10% of the target ratio. In yet another version of the present invention, they are considered to be approximately equal when the ratio is within 5% of the target ratio, and more preferably within 1% of the target ratio. The comparison in step 326 may indicate that the frequency characteristics of the first component of the drive signal are at or approximately equal to the target frequency of that component of the drive signal. This means that the drive signal is inducing expansion and contraction of the actuator 40, and as a result, the tip head is moving in the desired pattern. When the system 30 is in this state, the processor 272 proceeds to execute step 330.

[0085] In the evaluation of step 326, it may be determined that, as a result of the frequency characteristics of the first component of the drive signal, an output of the drive signal is occurring that does not induce the desired pattern with respect to tip head movement. When the processor 272 makes this determination, at step 328,

[0086]

[0087] The processor adjusts the frequency characteristic FREQ-COMP1 of the said component of the drive signal. Since the ratio regarding the left side of formula ( 2B) is negative, the calculation in step 164 that brings about a negative result is interpreted at sign 328 as an instruction by the processor 272 that the frequency characteristic of the first component of the drive signal should be increased. If the calculation in step 326 brings about a positive result then the processor 272 interprets the result as indicating that the handpiece is in a state where it is necessary to lower the frequency characteristic of the first component in order to enhance the possibility of the tip head passing through the desired travel path. After the execution of step 326, or after the execution of step 328 if necessary, the processor executes step 330. Step 330 is a comparison between the calculated equivalent current of the second component of the drive signal and the target of this equivalent current. Step 330 is substantially the same as step 322. The difference between step 322 and step 330 is that in step 330, the calculated

[0088]

number

number

number

[0089] If the two values are approximately equal, the voltage characteristic of the second component of the drive signal is not adjusted. The processor executes step 334.

[0089] If the two values compared in step 330 are not substantially equal, then in step 332, the processor resets the voltage characteristic of the second component of the drive signal. The meaning of step 332 is the same as step 324 for resetting the voltage characteristic of the first component of the drive signal. is substantially the same as the meaning in. As part of step 332, the processor 272 , based on any reset of the voltage characteristics of the second component of the drive signal, resets the WAVEFORM_SE T signal. The characteristics of the drive mode also change accordingly.

[0090] After step 330 and, if necessary, step 332 are executed, in step 3 34, the frequency characteristics of the second component of the drive signal are evaluated. This evaluation is performed using the same procedure as used in step 326 to evaluate the frequency characteristics of the first component of the drive signal. In step 334, the variables of the second component of the drive signal are applied to equation (2 B). In this use of equation (2B), the target frequency ω of the tip memory field 210 is used in the ratio change component to determine whether the second component of the drive signal has appropriate frequency characteristics . The coefficient m2 of the field 208 of the tip memory is used as the coefficient of the ratio change component. The evaluation in step 334 may indicate that the frequency characteristics of the second component of the drive signal are sufficiently equal to the target frequency. When the system 3 0 is in this state, the processor returns to step 310 to determine whether the control unit remains activated TARGET2 is . Or, the evaluation in step 334 may indicate that the frequency characteristics of the second component of the drive signal are not approximately equal to the target frequency. When the system 30 is in this state , the processor 276 resets this frequency characteristic in step 336 .

[0091] Alternatively, the evaluation in step 334 may indicate that the frequency characteristics of the second component of the drive signal are not approximately equal to the target frequency. When the system 30 is in this state , the processor 276 resets this frequency characteristic in step 336 .

[0092] After the execution of step 336, the processor returns to step 310. When this step is executed​​ In the case where the evaluation in step 310 indicates that the on-off switch remains activated, step 312 is executed again. Since the operator may input a command indicating that the magnitude of vibration should be reset from the previous setting, this step is executed again. Since the frequency characteristics and voltage characteristics of each component of the drive signal have been set previously, step 314 is not executed in this execution of the control loop. Instead, based on the set of drive signal component characteristics generated previously, step 315 is executed again. If the characteristics of the drive signal components have changed since step 315 was last executed, as a result, the processor 276 generates a new WAVEFORM_SET signal. Subsequently, the control console outputs a new drive signal whose characteristics are adjusted based on the adjustments calculated so far for the characteristics of each component of the drive signal accordingly. It should be understood that the reset frequency characteristics of each component of the drive signal are used as variables ω1 and ω2 to determine whether the drive signal induces the desired movement of the tip head 158 during subsequent execution of the control loop. There will inevitably come a time when the handpiece stops. The operator stops operating the on-off switch. When it is determined in step 310 that this event has occurred, the processor 276, as a result, asserts a command to terminate the application of the drive signal to the handpiece by the other elements of the console 240 (this step is not shown).

[0093] In the case where the evaluation in step 310 indicates that the on-off switch remains activated, step 312 is executed again. Since the operator may input a command indicating that the magnitude of vibration should be reset from the previous setting, this step is executed again. Since the frequency characteristics and voltage characteristics of each component of the drive signal have been set previously, step 314 is not executed in this execution of the control loop. Instead, based on the set of drive signal component characteristics generated previously, step 315 is executed again. If the characteristics of the drive signal components have changed since step 315 was last executed, as a result, the processor 276 generates a new WAVEFORM_SET signal. Subsequently, the control console outputs a new drive signal whose characteristics are adjusted based on the adjustments calculated so far for the characteristics of each component of the drive signal accordingly. It should be understood that the reset frequency characteristics of each component of the drive signal are used as variables ω1 and ω2 to determine whether the drive signal induces the desired movement of the tip head 158 during subsequent execution of the control loop. There will inevitably come a time when the handpiece stops. The operator stops operating the on-off switch. When it is determined in step 310 that this event has occurred, the processor 276, as a result, asserts a command to terminate the application of the drive signal to the handpiece by the other elements of the console 240 (this step is not shown). Since the frequency characteristics and voltage characteristics of each component of the drive signal have been set previously, step 314 is not executed in this execution of the control loop. Instead, based on the set of drive signal component characteristics generated previously, step 315 is executed again. If the characteristics of the drive signal components have changed since step 315 was last executed, as a result, the processor 276 generates a new WAVEFORM_SET signal. Subsequently, the control console outputs a new drive signal whose characteristics are adjusted based on the adjustments calculated so far for the characteristics of each component of the drive signal accordingly. It should be understood that the reset frequency characteristics of each component of the drive signal are used as variables ω1 and ω2 to determine whether the drive signal induces the desired movement of the tip head 158 during subsequent execution of the control loop. There will inevitably come a time when the handpiece stops. The operator stops operating the on-off switch. When it is determined in step 310 that this event has occurred, the processor 276, as a result, asserts a command to terminate the application of the drive signal to the handpiece by the other elements of the console 240 (this step is not shown).

[0094] Since the frequency characteristics and voltage characteristics of each component of the drive signal have been set previously, step 314 is not executed in this execution of the control loop. Instead, based on the set of drive signal component characteristics generated previously, step 315 is executed again. If the characteristics of the drive signal components have changed since step 315 was last executed, as a result, the processor 276 generates a new WAVEFORM_SET signal. Subsequently, the control console outputs a new drive signal whose characteristics are adjusted based on the adjustments calculated so far for the characteristics of each component of the drive signal accordingly. It should be understood that the reset frequency characteristics of each component of the drive signal are used as variables ω1 and ω2 to determine whether the drive signal induces the desired movement of the tip head 158 during subsequent execution of the control loop. There will inevitably come a time when the handpiece stops. The operator stops operating the on-off switch. When it is determined in step 310 that this event has occurred, the processor 276, as a result, asserts a command to terminate the application of the drive signal to the handpiece by the other elements of the console 240 (this step is not shown).

[0095] There will inevitably come a time when the handpiece stops. The operator stops operating the on-off switch. When it is determined in step 310 that this event has occurred, the processor 276, as a result, asserts a command to terminate the application of the drive signal to the handpiece by the other elements of the console 240 (this step is not shown). In the case where the evaluation in step 310 indicates that the on-off switch remains activated, step 312 is executed again. Since the operator may input a command indicating that the magnitude of vibration should be reset from the previous setting, this step is executed again. Since the frequency characteristics and voltage characteristics of each component of the drive signal have been set previously, step 314 is not executed in this execution of the control loop. Instead, based on the set of drive signal component characteristics generated previously, step 315 is executed again. If the characteristics of the drive signal components have changed since step 315 was last executed, as a result, the processor 276 generates a new WAVEFORM_SET signal. Subsequently, the control console outputs a new drive signal whose characteristics are adjusted based on the adjustments calculated so far for the characteristics of each component of the drive signal accordingly. It should be understood that the reset frequency characteristics of each component of the drive signal are used as variables ω1 and ω2 to determine whether the drive signal induces the desired movement of the tip head 158 during subsequent execution of the control loop.

[0096] Although not shown, at the initial setting of the WAVEFORM_SET signal and subsequent readjustments, in both cases, the processor 272 ensures that the drive signal is limited by the boundary characteristics read from both the handpiece memory 56 and the tip memory 184. These limitations are the voltage of the drive signal based on the maximum drive signal voltage of field 70 of the handpiece memory, the voltage characteristic of the first component of the drive signal based on the voltage data in field 191 of the tip memory, the voltage characteristic of the second component of the drive signal based on the voltage data in field 193 of the tip memory, the maximum current of the drive signal based on the data in field 66 of the handpiece memory, the maximum equivalent current to the handpiece based on the data in field 68 of the handpiece memory, the maximum equivalent current related to the first component of the drive signal based on the data in field 192 of the tip memory, and the maximum equivalent current related to the second component of the drive signal based on the data in field 194 of the tip memory. Including limiting the maximum equivalent current related to the second component of the drive signal based on the data in field 194 of the tip memory. The frequency characteristics of the drive signal are similarly set based on the data read from the handpiece memory 56 and the tip memory 184 respectively.

[0097] In this way, the data in fields 72 and 74 of the handpiece memory are used to define the overall boundary of the drive signal. The frequency range data in fields 196 and 198 of the tip memory defines the frequency range of the frequency characteristics of the first component of the drive signal. The frequency range data in fields 206 and 208 of the tip memory defines the frequency range of the frequency characteristics of the second component of the drive signal. As described above, the system 30 of the present invention, in a single vibration cycle, the tip head As described above, the system 30 of the present invention, in a single vibration cycle, the tip head As described above, the system 30 of the present invention, in a single vibration cycle, the tip head

[0098] As described above, the system 30 of the present invention, in a single vibration cycle, the tip head The tip head 158 is vibrated so that a point on the tip does not simply reciprocate along a line. Instead, the point is involved in a non-linear path. When the point on the head moves against the bone, the teeth hit the bone and immediately grind against it. When the teeth strike the bone, they break the bone, leading to the removal of tissue. This removes the newly removed material from the bone. The time between when the bone is removed and when the removed tissue is removed is short. There is only a relatively small amount of debris in the crater. Thus, the extent to which the presence of these debris adversely affects the bone resection process is similarly reduced.

[0099] When the system of the present invention drives the teeth of the tip head in a nonlinear motion, In the case of a toothed tooth, essentially the entire circumference of the tooth is pressed against the tissue against which the tip head is placed. This movement of the teeth against the tissue results in the desired abrasion of the tissue. In a single cycle of movement, essentially the entire surface of the tooth is pressed against the tissue. As the teeth are rotated, each surface is subject to at least some wear. Reduces the extent to which surfaces are subject to apparent uneven wear. Minimizes uneven wear of individual teeth. It is believed that by keeping the tooth extraction efficiency to a minimum, the degree to which it decreases can be similarly reduced. The efficiency of the removal of the apical set of teeth in one procedure is such that the apical part is replaced without any need for replacement. This reduces the possibility of deterioration to a level that requires

[0100] Furthermore, essentially every tooth surface is pressed against the tissue during a single motion cycle. Therefore, in that cycle, a single surface of a tooth is not pressed against tissue for a long time. Thus, over a long period of time, the surface is not constantly pressed against the tissue as would occur if it were constantly pressed against the tissue for a long time. This suppresses heating due to friction on the tooth surface that could occur if the surface were constantly pressed against the tissue. This suppression of heating reduces the extent to which this heat, even if it unavoidably occurs, could damage the tissue surrounding

[0101] It should be further understood that the system 30 can vibrate the tip in a plurality of vibration modes comprising different frequencies. It is possible to use a plurality of tips with this system, and the tips are not limited to those that vibrate at a common frequency when vibrating in two modes. When vibrating in a plurality of modes, there are significant manufacturing constraints and costs associated with having to provide tips that vibrate at a common frequency. These constraints and costs are usually irrelevant when providing tips that vibrate at different frequencies when vibrating in a plurality of modes. Therefore, the system 30 of the present invention enhances the feasibility of providing different tips that can vibrate simultaneously in different modes, with respect to both manufacturing and economic aspects.

[0102] A further feature of the present invention is that the operator can set a non-linear path for the tip head. More specifically, in response to the operator setting this path, the processor 276, in step 308, sets an individual maximum equivalent current i SELECTMAX-X for each vibration mode. One current i is set to be relatively large, and a second current i SELECTMAX-X is set to be relatively large, and a second current i is set to be relatively large, and a second current iSELECTMAX-X By setting it to be relatively small, the resulting drive signal causes the tip to undergo a relatively large movement along the first vibration path and a relatively small movement along the second vibration path in a single movement cycle of the tip head. In a single movement cycle of the tip head, the resulting drive signal causes the tip to undergo a relatively large movement along the first vibration path and a relatively small movement along the second vibration path. In a single movement cycle of the tip head, the resulting drive signal causes the tip to undergo a relatively large movement along the first vibration path and a relatively small movement along the second vibration path. The current i for the two vibration modes SELECTMAX-X is set to be approximately equal, so that the drive signal results in the tip being able to undergo more equivalent simultaneous movements with respect to displacement in two different vibration paths. The drive signal will result in the tip being able to undergo more equivalent simultaneous movements with respect to displacement in two different vibration paths. will result in.

[0103] Sometimes, the operator may want to apply the tip head to tissue that is significantly radially spaced from the longitudinal axis of the tip shaft. To perform the procedure on tissue located in such a position, it is desirable to provide a tip portion with a head that is asymmetrically positioned with respect to the longitudinal axis of the tip shaft. To perform the procedure on tissue located in such a position, it is desirable to provide a tip portion with a head that is asymmetrically positioned with respect to the longitudinal axis of the tip shaft. To perform the procedure on tissue located in such a position, it is desirable to provide a tip portion with a head that is asymmetrically positioned with respect to the longitudinal axis of the tip shaft. Due to this asymmetry, the tip head necessarily vibrates in multiple modes. Usually, these vibration modes are at different frequencies. The system 30 of the present invention controls the vibrations in these multiple modes so that when the tip head vibrates, its movement is predictable and leads to an efficient removal of tissue along a path. Due to this asymmetry, the tip head necessarily vibrates in multiple modes. Usually, these vibration modes are at different frequencies. The system 30 of the present invention controls the vibrations in these multiple modes so that when the tip head vibrates, its movement is predictable and leads to an efficient removal of tissue along a path. By controlling the vibrations in these multiple modes, when the tip head vibrates, its movement is predictable and leads to an efficient removal of tissue along a path. By controlling the vibrations in these multiple modes, when the tip head vibrates, its movement is predictable and leads to an efficient removal of tissue along a path. can be ensured.

[0104] Furthermore, since the tip head that vibrates according to the present invention moves in a non-linear pattern, each tooth tends to push the excised tissue out of the progression path. Removing the tissue from the teeth in this way reduces the degree to which these debris reduce the efficiency of tissue excision in subsequent vibration cycles. Furthermore, since the tip head that vibrates according to the present invention moves in a non-linear pattern, each tooth tends to push the excised tissue out of the progression path. Removing the tissue from the teeth in this way reduces the degree to which these debris reduce the efficiency of tissue excision in subsequent vibration cycles. Furthermore, since the tip head that vibrates according to the present invention moves in a non-linear pattern, each tooth tends to push the excised tissue out of the progression path. Removing the tissue from the teeth in this way reduces the degree to which these debris reduce the efficiency of tissue excision in subsequent vibration cycles. Reducing the degree to which these debris reduce the efficiency of tissue excision in subsequent vibration cycles.

[0105] The above description relates to one version of the system of the present invention. Other versions of the system of the present invention may have features different from those previously described. For example, some tips of this system may have three or more vibration modes. In this system configuration, the drive signal will have three or more components. It should be further understood that the target frequency characteristics for some of these components may not be the same but may be close to each other. Similarly, sometimes the equivalent

[0106] current applied to the mechanical elements of the handpiece may be approximately the same, but not exactly, for multiple components of the drive signal. The structure of the elements of the system may be different from that described. Therefore, in some versions of the system, there are multiple signal generators inside the console that operate simultaneously and independently of each other. The processor adjusts the voltage and frequency of the signals generated by each of these signal generators. More specifically, the processor controls each signal generator so

[0107] that it outputs a specific component of the drive signal. These individual components are added to each other to generate the drive signal applied to the handpiece driver 36. In some versions of the present invention, the assembly that supplies the drive

[0108] signal to the handpiece may not include an amplifier that changes the voltage applied To provide measurement results of the current flowing through the bit and the handpiece, it should be understood that assemblies other than the disclosed coils 256 and 264 may be utilized. In some versions of the present invention, one or more resistor networks can provide signals on which these measurement results of voltage and current are determined.

[0109] In all versions of the present invention, the driver capacitance need not be based on data read from memory integrated with the handpiece. In alternative versions of the present invention, the processor outputs drive signals at various frequencies and determines the capacitance of the driver by measuring the voltage and current of the drive signals.

[0110] In some versions of the present invention, based on performing a frequency sweep, the processor identifies the resonance and anti-resonance modes of each vibration mode.

[0111] In some configurations of the present invention, the travel path of a point on the tip head 158 is non-linear for any intention and purpose, but it should be understood that the path appears as a linear path.

[0112] In FIG. 11, the illustrated non-linear path is considered to be a path that is basically elliptical. It should be understood that this is an example and is not limited thereto. Other single vibration paths of the present invention may have other shapes. These shapes include basically circular and basically crescent shapes. Further, it is also within the scope of the present invention for non-linear paths to include paths that intersect each other. The conventional form of this type of path is an 8-shaped path.

[0113] In some versions of the present invention, the potential of one or more of the components of the drive signal is fixed and may be applied to the mechanical elements of the handpiece. In these versions of the present invention, the equivalent current applied to the mechanical elements of the handpiece is controlled by adjusting the target frequency associated with that component.

[0114] Furthermore, although the frequency characteristics of the components of the drive signal generally differ, it should be understood that this is not always the case. Sometimes, based on the type of mechanical load applied to the tip 158, the frequency characteristics of two or more components of the drive signal may be the same.

[0115] Therefore, the purpose of the appended claims is to encompass all such changes and modifications that fall within the true spirit and scope of the present invention. ​​​

Claims

1. An assembly for vibrating the tip of an ultrasonic surgical tool, said assembly being connected to said ultrasonic surgical tool, said ultrasonic surgical tool having at least one driver to which an AC drive signal is applied to vibrate said tip, said tip being configured to vibrate in a plurality of vibration modes, each of said plurality of vibration modes being associated with certain frequency characteristics, an assembly for generating a variable AC drive signal to be applied to said at least one driver, an assembly for measuring the voltage of said AC drive signal, an assembly for measuring the current of said AC drive signal, a processor and said processor being based on the measured voltage of said AC drive signal and the measured current of said AC drive signal, calculating the voltage characteristics of the components of said AC drive signal for each of said plurality of vibration modes, asserting a command to the assembly for generating said AC drive signal so that the assembly for generating said AC drive signal can generate an AC drive signal including components for each vibration mode based on the frequency characteristics associated with each of said plurality of vibration modes and the voltage characteristics calculated for each of said plurality of vibration modes. Assembly.

2. said processor asserting said command to the assembly so that the assembly for generating said AC drive signal can generate an AC drive signal including components for each vibration mode based on the frequency characteristics associated with each of said plurality of vibration modes and the voltage characteristics calculated for each of said plurality of vibration modes, said AC drive signal being applied to said at least one driver such that the head of said tip travels along a non-linear travel path in a single vibration cycle, An assembly for vibrating the tip of an ultrasonic surgical tool according to claim 1.

3. The processor asserts the command to the assembly so that the assembly that generates the AC drive signal can generate an AC drive signal including components for each vibration mode based on the frequency characteristics associated with each of the plurality of vibration modes and the voltage characteristics calculated for each of the plurality of vibration modes. When the AC drive signal is applied to the at least one driver, the head at the tip moves in a loop shape. An assembly for vibrating the tip of the ultrasonic surgical tool according to claim 1 or 2.

4. The processor receives the set travel path of the head at the tip of the ultrasonic surgical tool by the operator, calculates the voltage characteristics for each of the plurality of vibration modes based on the measured voltage of the AC drive signal, the measured current of the AC drive signal, and the travel path set by the operator, The processor asserts the command to the assembly so that the assembly that generates the AC drive signal can generate an AC drive signal including components for each vibration mode based on the frequency characteristics associated with each of the plurality of vibration modes and the voltage characteristics calculated for each of the plurality of vibration modes. When the AC drive signal is applied to the at least one driver, the head at the tip moves along the travel path set by the operator in a single vibration cycle. An assembly for vibrating the tip of the ultrasonic surgical tool according to any one of claims 1 to 3.

5. The processor Based on a command set by the operator, for each of the plurality of vibration modes, obtains a target equivalent value of the current flowing through the mechanical elements of the ultrasonic surgical tool. Calculate the voltage characteristics of each of the plurality of vibration modes based on the measured voltage of the AC drive signal, the measured current of the AC drive signal, and the target equivalent value of the current flowing through the mechanical elements of the ultrasonic surgical tool for the vibration mode. An assembly for vibrating the tip of an ultrasonic surgical tool according to any one of claims 1 to 3.

6. The command set by the operator indicates the travel path of the tip. The processor obtains the target equivalent value of the current flowing through the mechanical elements of the ultrasonic surgical tool for each of the plurality of vibration modes. By applying the AC drive signal to the at least one driver, the head of the tip moves in a single vibration cycle along the indicated travel path. An assembly for vibrating the tip of an ultrasonic surgical tool according to claim 5.

7. The processor For each vibration mode of the tip, obtain the maximum equivalent value of the current flowing through the mechanical elements of the ultrasonic surgical tool. Based on the command set by the operator, obtain the coefficient of each of the plurality of vibration modes. For each of the plurality of vibration modes, obtain the target equivalent value of the current flowing through the mechanical elements of the ultrasonic surgical tool based on the maximum equivalent value of the current of the vibration mode and the coefficient of the vibration mode. An assembly for vibrating the tip of an ultrasonic surgical tool according to claim 5 or 6.

8. The processor Read data indicating the maximum equivalent value of the current for each vibration mode from the memory of the ultrasonic surgical tool. Based on the read data, obtain the maximum equivalent value of the current for each vibration mode of the tip. An assembly for vibrating the tip of an ultrasonic surgical tool according to claim 7.

9. The processor, reads data indicating the initial voltage characteristics for each vibration mode from the memory of the ultrasonic surgical tool, and before calculating the voltage characteristics for each vibration mode based on the measured voltage of the AC drive signal and the measured current of the AC drive signal, asserts a command to the assembly that generates the AC drive signal, so that the assembly can generate an AC drive signal including components for each vibration mode based on the frequency characteristics associated with each of the plurality of vibration modes and the initial voltage characteristics for each of the plurality of vibration modes indicated by the read data. An assembly for vibrating the tip of an ultrasonic surgical tool according to any one of claims 1 to 8.

10. The frequency characteristics of at least two of the plurality of vibration modes are different. An assembly for vibrating the tip of an ultrasonic surgical tool according to any one of claims 1 to 9.

11. The processor reads data indicating the frequency characteristics for each of the plurality of vibration modes from the memory of the ultrasonic surgical tool. An assembly for vibrating the tip of an ultrasonic surgical tool according to any one of claims 1 to 10.

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