System and method for driving ultrasonic handpiece as function of mechanical impedance of handpiece

Abstract

To apply a drive signal to a handpiece in response to a change in impedance of a mechanical component of the handpiece.SOLUTION: A voltage and frequency of a drive signal applied to a handpiece driver is a function of mechanical components of a handpiece and equivalent components of a current passing through a tip, and the frequency responsiveness of these components. A system performs: monitoring the voltage and the current of the drive signal flowing to the handpiece (154); calculating the equivalent component of the current applied to the mechanical components of the handpiece (155); setting a potential of the drive signal output from an assembly generating the drive signal based on the comparison of the currents (160); and setting the frequency of the drive signal output from the assembly generating an AC drive signal (166).SELECTED DRAWING: Figure 6B

Description

Technical Field

[0001] The present invention comprehensively relates to an ultrasonic-driven surgical handpiece. More specifically, the present invention relates to applying a driving signal to the handpiece according to a change in the impedance of a mechanical component of the handpiece.

Background Art

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

[0003] The heads of ultrasonic tips are often relatively small. Some heads have a diameter of less than 1.0 cm. Ultrasonic tools basically remove the tissue adjacent to the location where the head is applied. Therefore, 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 tissue. The heads of ultrasonic tips are often relatively small. Some heads have a diameter of less than 1.0 cm. Ultrasonic tools basically remove the tissue adjacent to the location where the head is applied. Therefore, 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 tissue.

[0004] In the case of ultrasonic surgical instruments, which may also be called handpieces or tools, a drive signal having appropriate characteristics should be applied to the tool for efficient operation. If the drive signal does not have appropriate characteristics, the tip head may receive vibrations that are less than the optimal amplitude and / or may not vibrate as fast as possible. If the handpiece is in any state, the ability of the handpiece at a given point in time to remove tissue is affected. In the case of ultrasonic surgical instruments, which may also be called handpieces or tools, a drive signal having appropriate characteristics should be applied to the tool for efficient operation. If the drive signal does not have appropriate characteristics, the tip head may receive vibrations that are less than the optimal amplitude and / or may not vibrate as fast as possible. If the handpiece is in any state, the ability of the handpiece at a given point in time to remove tissue is affected. If the handpiece is in any state, the ability of the handpiece at a given point in time to remove tissue is affected. It may decrease or fall.

[0005] One means of ensuring that the ultrasonic handpiece operates efficiently is to apply a drive signal at the resonant frequency of the handpiece to the handpiece. When the drive signal is at a given voltage or current, applying a drive signal at the resonant frequency induces vibration at the tip at a relatively large amplitude compared to applying the same voltage at a frequency off resonance. When the drive signal is at a given voltage or current, applying a drive signal at the resonant frequency induces vibration at the tip at a relatively large amplitude compared to applying the same voltage at a frequency off resonance. When the drive signal is at a given voltage or current, applying a drive signal at the resonant frequency induces vibration at the tip at a relatively large amplitude compared to applying the same voltage at a frequency off resonance. is induced.

[0006] Still other ultrasonic tool systems are designed to apply a drive signal at the anti - resonant frequency of the handpiece. The anti - resonant frequency can be the frequency at which the handpiece will have its highest impedance. Still other ultrasonic tool systems are designed to apply a drive signal at the anti - resonant frequency of the handpiece. The anti - resonant frequency can be the frequency at which the handpiece will have its highest impedance. is induced.

[0007] The applicant's SONOPET (trademark) ultrasonic aspirator has a console with components designed to generate a variable drive signal and apply it to an attached handpiece. There is a resonant circuit inside the console. At the time of manufacturing the console, the inductance and capacitance of this resonant circuit are set as a function based on the impedance of a particular handpiece intended to be used with the console. The characteristics of the drive signal output from the console are set according to the voltage across this impedance circuit. The applicant's SONOPET (trademark) ultrasonic aspirator has a console with components designed to generate a variable drive signal and apply it to an attached handpiece. There is a resonant circuit inside the console. At the time of manufacturing the console, the inductance and capacitance of this resonant circuit are set as a function based on the impedance of a particular handpiece intended to be used with the console. The characteristics of the drive signal output from the console are set according to the voltage across this impedance circuit. The applicant's SONOPET (trademark) ultrasonic aspirator has a console with components designed to generate a variable drive signal and apply it to an attached handpiece. There is a resonant circuit inside the console. At the time of manufacturing the console, the inductance and capacitance of this resonant circuit are set as a function based on the impedance of a particular handpiece intended to be used with the console. The characteristics of the drive signal output from the console are set according to the voltage across this impedance circuit. The applicant's SONOPET (trademark) ultrasonic aspirator has a console with components designed to generate a variable drive signal and apply it to an attached handpiece. There is a resonant circuit inside the console. At the time of manufacturing the console, the inductance and capacitance of this resonant circuit are set as a function based on the impedance of a particular handpiece intended to be used with the console. The characteristics of the drive signal output from the console are set according to the voltage across this impedance circuit. is set. The applicant's SONOPET (trademark) ultrasonic aspirator has a console with components designed to generate a variable drive signal and apply it to an attached handpiece. There is a resonant circuit inside the console. At the time of manufacturing the console, the inductance and capacitance of this resonant circuit are set as a function based on the impedance of a particular handpiece intended to be used with the console. The characteristics of the drive signal output from the console are set according to the voltage across this impedance circuit. is set.

[0008] In many procedures, the SONOPET console outputs a drive signal. This drive signal is basically the same as, or at least close to, the resonant frequency of the mechanical components of the handpiece. However, in many normal usage situations, the ultrasonic is basically the same as, or at least close to, the resonant frequency of the mechanical components of the handpiece. However, in many normal usage situations, the ultrasonic The handpiece may be subject to significant mechanical loads. This may occur, for example, when the tip is pressed against bone. In this situation, the mechanical load applied to the tip may cause a significant change in the impedance of the mechanical components of the handpiece . When this event occurs, the control console may not be able to output a drive signal at a frequency close to the resonance frequency of the mechanical components of the handpiece.

[0009] Furthermore, the impedance circuit inside a prior art console is typically set with inductance and capacitance according to a specific handpiece that the console is to be used with. When a handpiece having different internal inductance, capacitance, and resistance is attached to the console, the drive signal output from the console is very likely not to have characteristics that promote efficient operation of the handpiece. This makes it difficult, if not impossible, to use a console designed to be used with one handpiece as a power source to supply a drive signal to another handpiece. SUMMARY OF THE INVENTION

[0010] The present invention relates to a novel and useful ultrasonic surgical tool system. The tool system of the present invention is designed to ensure that, within the design limits, the drive signal applied to the system handpiece induces vibrations of an appropriate amplitude at the tip of the handpiece. More specifically, when various handpieces are attached to the control console, the system can set the drive signal accordingly. Also, the system uses the handpiece As a result, when the impedance characteristics of the handpiece change, the characteristics of the drive signal are adjusted.

[0011] The system of the present invention has a control console to which the handpiece is attached. The control co nsole generates a drive signal and supplies it to the handpiece. The control console sets the frequency of the drive signal and the current supplied to the handpiece. The supplied current is set by controlling (regulating) the voltage of the drive signal . These characteristics of the drive signal are set according to two variables and one constant. One of the variables is the voltage of the drive signal . The second variable is the current passing through the handpiece, i.e., the current of the drive signal. The constant is the capacitance of one or more piezoelectric drivers inside the handpiece. Based on these three inputs, the control console sets the frequency and voltage level of the drive signal

[0012] . The frequency of the drive signal is set to match the target frequency as closely as possible . This ensures that the vibration of the tip head is at its most efficient frequency . The voltage is set to provide control over the amplitude of the vibration of the tip head. In some versions of the present invention, the drive signal is adjusted to control the equivalent component of the current applied to the mechanical components of the handpiece

[0013] . The frequency of the drive signal can be adjusted to ensure that the signal is at a target frequency related to the resonance frequency and / or anti - resonance frequency of the mechanical components of the handpiece . The voltage and current of the drive signal are measured by a circuit inside the control console.

[0014] ​

[0015] The driver capacitance is considered constant in that it remains unchanged over many series of adjustments of the drive signal. In some versions of the present invention, the driver capacitance is obtained from data read from a memory configured integrally with a handpiece attached to the console. Alternatively, based on a set of interrogation signals, the console can periodically request the driver capacitance.

[0016] The target frequency of the handpiece is, in part, a function of the mechanical components of the handpiece. Also, the target frequency is a function of the varying load applied to these components. The target frequency can be the resonant frequency of the mechanical components of the handpiece. In some versions of the present invention, the target frequency is the anti-resonant frequency of the mechanical components of the handpiece. In yet another version of the present invention, the target frequency is a frequency between the resonant frequency and the anti-resonant frequency of the mechanical components of the handpiece. In yet another version of the present invention, the target frequency is outside the band between the resonant frequency and the anti-resonant frequency.

[0017]

[0018] ​​​​​​​​​​​​​​​​ It is not necessary to connect to only a single specific console.

[0019] In some alternative versions of the present invention, only the frequency of the drive signal is set. This frequency is regulated to ensure that it results in an equivalent component of the current to which the drive signal is applied to the mechanical components of the handpiece and that the signal is at a frequency close to the desired target frequency for these components.

[0020] The present invention is set forth in detail in the claims. The above features and advantages of the present invention, as well as further features and advantages, will be understood from the following detailed description taken in conjunction with the following drawings.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

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Figure 4B

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Figure 6B

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Figure 15A

Figure 15B

[0022] [I. System Overview and Hardware] Regarding the ultrasonic tool system 30 having the mechanism of the present invention, refer to FIGS. 1 and 2. will be described comprehensively. System 30 has a handpiece 32. The handpiece 3 2 has a body or shell 34 that forms the proximal end of the handpiece. (“Proximal” is understood to mean close to the operator holding the handpiece and far from the site where the handpiece is applied. “Distal” is understood to mean far from the operator and close to the site where the handpiece is applied.) ).

[0023] One or more vibratory piezoelectric drivers 40 (four are shown) are disposed inside the shell 34. Each driver 40 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 40, which extends between the proximal and distal faces of the driver. A pair of leads 41 extend away from each driver 40. The leads 41 are attached to the opposing proximal and distal faces of the driver. Although not all, many handpieces 32 have disk-shaped piezoelectric drivers 40. These drivers 40 are arranged such that their end faces face each other within the stack. The leads 41 are components of the system 3 0, and an electric current is applied to the driver 40 in the form of a drive signal. Insulating disks 37 separate adjacent leads 41 connected to adjacent drivers 40 from each other. One of the insulating disks 37 is shown. In FIG. 2, the drivers 40 are shown as being spaced apart from each other. This is for ease of illustration of the components. In reality, the insulating disks 37 and the drivers 40 are in abutment without a gap. ​

[0024] A post 39 extends longitudinally through the insulating disk 37 and the driver 40 . Post 39 extends through the driver along a collinear longitudinal axis of the driver. The insulating disk 37 and the driver 40 are internal to the post 39 passing therethrough. The post 39 is connected to the proximal most driver 40. and the distal-most driver.

[0025] A proximal end mass is provided on the proximal face of the proximal-most driver 40. 36 is attached to the exposed proximal end face of the post 39. If the post 39 is threaded, the mass 36 may be a nut.

[0026] A horn 42 extends forward from the distal face of the distal-most driver 40 . Although not shown, there may be an insulating disk 37 between these components. 2 has a base with a diameter approximately equal to the diameter of the driver 40. As the horn 42 extends forward from the distal end, the diameter of the horn 42 decreases. A horn 42 is secured to the distal end surface of the post 39. When the post 39 is threaded, the horn The base of the pin has a threaded, closed-ended bore (not shown) to receive the post 39. The handpiece 32 may be configured such that the stack of drivers 40 is in contact with the proximal mass 36. The screw 42 is configured to be clamped between the screw 42.

[0027] A tip 48 extends forward from the distal end of the horn 42. The coupling assembly typically removably holds the distal end 48 between the horn 42 and the remainder of the handpiece 32. The structure of the coupling assembly is not part of the present invention. The distal end 48 has an elongated stem 50. The stem 50 is part of the distal end and is attached to the horn 42 through the coupling assembly. The stem 50 extends forward of the handpiece shell 34. The distal end 48 is formed to have a head 52 at the distal end of the stem 50. Some of the tip heads 52 have smooth surfaces. Some of the heads 52 have teeth 53 formed thereon. The shape of the head 52 is not part of the present invention. The tip head 52 is the part of the handpiece 32 that is applied to the site of the patient where the procedure is being performed. Some distal ends 48 are provided with teeth designed to be applied directly to hard tissue, i.e., bone. When this type reciprocates, the teeth cut tissue in the same way that conventional serrated teeth cut tissue. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. Some of the tip heads 52 have smooth surfaces. Some of the heads 52 have teeth 53 formed thereon. The shape of the head 52 is not part of the present invention. The tip head 52 is the part of the handpiece 32 that is applied to the site of the patient where the procedure is being performed. Some distal ends 48 are provided with teeth designed to be applied directly to hard tissue, i.e., bone. When this type reciprocates, the teeth cut tissue in the same way that conventional serrated teeth cut tissue. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve.

[0028] Some distal ends 48 are provided with teeth designed to be applied directly to hard tissue, i.e., bone. When this type reciprocates, the teeth cut tissue in the same way that conventional serrated teeth cut tissue. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve.

[0029] A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. A sleeve 55, represented as a ring in Figure 2, is typically arranged to cover the distal shaft 50. The sleeve 55 usually extends from a location near where the shaft is attached to the horn 42 to a location approximately 0.5 cm close to the head 52. The handpiece 32, the distal end 48, and the sleeve 55 are configured such that the sleeve defines a fluid flow conduit that extends between the outer surface of the distal end and the inner surface surrounded by the sleeve. The sleeve 55 also has a mounting fitting (not shown) adjacent to the proximal end of the sleeve and extending to this conduit. The conduit opens at the distal end of the sleeve. It is. When the handpiece is in use, the cleaning solution flows from the sleeve mounting fitting under the sleeve towards the distal end and is discharged adjacent to the tip head 52. In some versions of the system the fluid serves as a medium through which the mechanical vibrations of the tip head are transmitted to the tissue. This cleaning solution also functions as a heat sink for the heat energy generated by the tip head as a result of the head's vibration.

[0030] Although not shown, the tip portion, horn 42 and handpiece post 39 often define together a conduit that defines the fluid flow path from the tip head 52 to the proximal end of the handpiece. When the handpiece is operating, suction occurs through these conduits. The suction is discharged through the sleeve 55 and draws in the cleaning fluid that is leaving the site where the tip is applied. Also, the suction draws the tissue towards the tip head. By shortening the distance between the tip head and the tissue, the transmission of mechanical vibrations from the tip head to the tissue is improved.

[0031] Also, the handpiece 32 also has a memory 58. The memory 58 contains data that describes the characteristics of the handpiece, as will be discussed later. The memory 58 can take the form of an EPROM, EEPROM or RFID tag. The structure of the memory is not part of the present invention. Most handpieces 32 of the present invention include a memory that, in addition to containing data that can be read, can store data that is written to the memory after the handpiece is manufactured. Auxiliary components (not shown) read the data from the memory. To facilitate data writing to the memory, it is attached to the handpiece . These components consist of one or more of the following components, namely, conductors, exposed contacts / contact pins, coils / antennas, or isolation circuits .

[0032] The control console 64 is also part of the system 30 of the present invention. The control console 64 supplies a drive signal via a cable 62 to which the handpiece 32 is connected . In many versions, although not all, of the system 30, the handpiece 32 and the cable 62 are assembled as a single unit . The drive signal is applied to the driver 40. At any given point in time, the same drive signal is applied to each driver 40 . By applying the drive signal, the driver expands and contracts simultaneously and periodically . The stack of drivers 40 is often 1 cm to 5 cm in length . The distance of movement of the driver during one expansion and contraction cycle, i.e., the amplitude, can be 1 micron to 10 microns . The horn 42 amplifies this movement . As a result, when moving from the fully contracted position to the fully expanded position, the distal end of the horn 42 and, considering its extension, the tip head 52 typically move a maximum of 1000 microns and, in more cases, 500 microns or less . Depending on the tip portion 48, the longitudinal expansion and contraction of the tip shaft also induce a rotational movement in the head . When the handpiece 32 operates to cause a periodic movement of the tip portion, the head 52 can be considered to be vibrating . . . .

[0033] As shown in FIG. 3, the components inside the control console 64 include a power supply 68 It does. The power supply 68 usually outputs a constant voltage signal of 1 VDC to 250 VDC. In many versions of the present invention, the maximum potential of the voltage output by the power supply 68 is 150 VDC or less and there is. The potential of the signal output by the power supply 68 can be selectively set. In the version described in the present invention, the power supply 68 receives a VOLTAGE_SET (V_S) signal . The power supply 68 establishes the level of the output voltage according to the VOLTAGE_SET signal. The output voltage generated by the power supply 68 is applied to an adjustable amplifier 70. A control signal , specifically, a FREQUENCY_SET (F_S) signal, is applied to the amplifier 70 . The frequency of the output signal generated by the amplifier 70 corresponds to the FREQUENCY_SET signal . The output signal from the amplifier 70 is applied to a filter 72. In some versions of the present invention , the amplifier 70 is often a class D amplifier. The output signal from the amplifier 70 is applied to the filter 72. The filter 72 outputs a sine wave version of the square wave applied from the amplifier 70 to the filter . In some versions of the present invention, the filter 72 is a bandpass filter. The signal output from the filter 72 is usually 1 0 kHz to 100 kHz. Often, the signal has a minimum frequency of 20 kHz .

[0034] The output signal from the filter 72 is applied to a primary winding 78 of a transformer 76, which is also part of the control console 64. The voltage present across the secondary winding 82 of the transformer 76 is the drive signal applied to the handpiece driver 40 through the cable 62. This voltage is usually a maximum of AC peak 1500 volts. The drive signal is applied in parallel across both ends of the driver 40 . This is done. More specifically, the drive signal is applied in parallel to each pair of leads 41.

[0035] The transformer 76 has a reproduction coil 80. The voltage existing at both ends of the reproduction coil 80 is applied to the voltage measurement circuit 86. Based on the signal applied to the reproduction coil 80, the circuit 86 generates a signal representing the voltage V of the drive signal applied to the handpiece 32 S and its potential and phase. The coil 90, which is also arranged within the control console 64, is positioned extremely close to one of the conductors extending from the secondary winding 8 2 of the transformer. The signal applied to the coil 90 is applied to the current measurement circuit 92. The circuit 92 generates a signal representing the magnitude and phase of the current i, which is the current of the drive signal supplied to the handpiece. S

[0036] The V S signal and the i S signal representing the characteristics of the drive signal supplied to the piezoelectric driver 40 are also applied to the processor 96 inside the control console 64. Also, the control console 64 has a memory reader 102. The memory reader 102 can read the data in the handpiece memory 58. The structure of the memory reader 102 complements the handpiece memory 1 02. Therefore, the memory reader can be an assembly that can read the data in an EPROM or EEPROM, or an assembly that queries an RFID tag and can read the data from the RFID tag. In some versions of the present invention where the data read from the memory 5 8 is read through the conductor through which the drive signal is supplied to the handpiece 32, the memory reader includes an isolation circuit. ​​​​​It is possible. The data read by the reader 102 is applied to the processor 96 to be.

[0037] The processor 96 generates a VOLTAGE_SET signal applied to the power supply 68. Also the processor 96 generates a FREQUENCY_SET signal applied to the amplifier 70 to be. These signals are control signals for regulating (or controlling) the voltage and frequency of the drive signal supplied by the control console 64. The processor 96 is based on the characteristics of the handpiece and the measured values obtained with respect to V S and i S to assert the control signal according to. to be.

[0038] Connected to the control console 64 is an on / off switch. In FIG. 1, the on / off switch is represented by the foot pedal 104. The state of the pedal 104 is monitored by the processor 96. The on / off switch is a user-operated control member for regulating the on / off state of the system 30. In FIG. 1, the foot pedal 1 04 is shown as part of a foot pedal assembly including a plurality of pedals. Additional pedals can be used to control devices such as a cleaning pump, a suction pump, or a light to be. These auxiliary devices are not part of the present invention. to be. to be. to be.

[0039] The control console 64 is shown as having a slide switch 106. Similar to the switch 104, the state of the switch 106 is monitored by the processor 96. to be. The switch 106 is used by the operator to control the amplitude of the vibration of the tip head 52 It is set. The foot pedal 104 and the switch 106 generally represent means for inputting on / off and amplitude setting commands to the system 30. It should be understood that in some configurations of the system a single control member can perform both functions. Thus when the lever or foot pedal is first depressed, the system can be configured so that the tip head receives a vibration cycle consisting of a relatively small amplitude. As a result of continuously depressing the lever or foot pedal, the control console resets the drive signal applied to the handpiece so that the tip head 52 receives a vibration cycle consisting of a larger magnitude.

[0040] The display 108 is built into the control console 64. The image on the display 108 is shown as being generated by the processor 96. The information represented on the display 108 includes information identifying the handpiece and, optionally, the tip portion, and information describing the operating speed characteristics of the shaft.

[0041] [II. Operating Principle] The plurality of components that make up the control console 64 are configured to output a drive signal to the handpiece, ideally resulting in a relatively large reciprocating back-and-forth vibration of the tip head 52 (the amplitude of the head movement is as large as possible). This is because the effectiveness with which the tip portion can remove tissue generally relates to the length of the movement of the tip head while in contact with the tissue.

[0042] One means of facilitating the large amplitude reciprocating movement of the tip head 52 is, within design limits, the ​​​It is to maximize and hold the current of the drive signal applied to the handpiece. This is because there is a proportional relationship between the current applied to the handpiece 32 and the amplitude of the movement of the tip head exists. The current i S applied to the handpiece can be considered mathematically to have two components shown in FIGS. 4A and 4B. The first component is the current i O , that is, the current applied to the capacitor of the driver 4 0. The second component is the current i M , that is, the mathematically equivalent component of the current applied to the mechanical components of the hand piece 32. The mechanical components of the handpiece are components of the handpiece that vibrate in response to the application of the drive signal . These components include the proximal mass 36, the post 39, the driver 40, the horn 42 having a coupling assembly , and the tip portion 48. The driver 40 is included in a part of these components . The reason is that since the driver 40 vibrates, it is a part of the mechanical assembly that vibrates in the present invention . The sleeve 55 is not usually regarded as one of these components . This is because although the sleeve 55 vibrates, the sleeve is not part of the vibration system. More specifically, the sleeve 55 can be regarded as a component that applies a load to the vibration system .

[0043] This system of the present invention is designed to keep the equivalent component i of the current applied to the mechanical components constant, apart from the change in the impedance of the handpiece M .

[0044] Based on the impedance of the components forming the handpiece 32, the current i M is obtained ​Therefore, it is controlled. The driver 40 of the handpiece and the mechanical components can be considered as two impedance circuits connected in parallel. Here, z is the impedance of the stack of the driver 40. The impedance of the driver is basically a function of the capacitance C O of the driver 40 and the frequency of the drive signal. This model assumes that the capacitance of the cable 62 and any other components through which the drive signal passes when applied to the driver is negligible. Therefore, the impedance Z has only a capacitive reactance component, 1 / jωC . The variable "ω" is the angular O wavenumber of the drive signal. The impedance Z has a negligible resistive reactance component and inductive reactance component. O That is , it has only the capacitive reactance component, 1 / jωC O . The variable "ω" is the angular wavenumber of the drive signal. The impedance Z O has a negligible resistive reactance component and inductive reactance component.

[0045] The impedance Z M is the mathematical equivalent component of the effective impedance of the mechanical components of the handpiece. The impedance Z M is based on the mechanical equivalent components of the inductance L of the mechanical components of the handpiece, the resistance R M , and the capacitance C M . The impedance M is the impedance of the entire handpiece. Therefore, the impedance Z is calculated according to the following formula. H That is, the impedance Z H is calculated according to the following formula.

Equation

[0046] In the case of the models of FIGS. 4A and 4B,

Equation

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[0047] In addition to regulating the equivalent component of the current applied to the mechanical components of the handpiece 32, the system 30 of the present invention regulates the frequency of the drive signal. More specifically, the drive frequency is regulated to be the target frequency based on the resonance frequency of the mechanical components of the handpiece 32. Although not always, in many cases, the resonance frequency of the mechanical components is the target frequency. Assuming a constant equivalent component of the current, and the mechanical components is the target frequency. Assuming a constant equivalent component of the current, and the mechanical components is the target frequency. Assuming a constant equivalent component of the current, and the mechanical components When vibrating at the resonant frequency, the periodic expansion and contraction (vibration) of the handpiece is highest and thus the resonant frequency is selected as the target frequency. A particular resonance type is called mechanical resonance.

[0048] One process by which the frequency of the drive signal can be set in this way is based on the understanding that, in mechanical resonance, the current passing through the stack of the driver 40 and the mechanical components should be out of phase by 90 degrees. This is because the capacitive reactance and inductive reactance phase shift effects of the mechanical components of the handpiece cancel each other out. The driver has a negligible inductive reactance in the frequency range to which the drive signal is applied. As a result, the driver induces a 90-degree phase shift in the current, but no 90-degree phase shift is induced in the equivalent component of the current applied to the mechanical components of the handpiece.

[0049] Current i O and i M can be expressed in polar form as follows.

Equation

Equation

Equation

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[0050] The driver current according to the above formula (4B) and the mechanical configuration of the handpiece according to formula (5) Substituting the equivalent components of the current applied to the element into the relationship in equation (10) gives the following at mechanical resonance: This means that the following relationship holds:

number

[0051] [III. Actual Operation] To facilitate the operation of the system 30, data is loaded into the memory 58 inside the handpiece during the assembly of the handpiece. These data, as represented by the field 112 in FIG. 5, include data for identifying the handpiece 32. These data are useful for verifying that the console 64 can apply a drive signal to the handpiece. The data within the field 112 can also indicate the type of information regarding the handpiece presented on the console display 108. The field 114 contains data indicating the capacitance C of the stack of the driver 40 which can be determined by analysis during the process of assembling the handpiece 34. In many cases, the sum of the capacitances of the driver is between 500 pF and 5000 pF. The maximum current applied to the handpiece, i.e., the current is included in the field 116. The current

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[0052] Also stored in the handpiece memory is data indicating the minimum and maximum frequencies of the drive signal applied to the handpiece 32. The minimum frequency stored in field 122 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 124 is usually between 5 kHz and 40 kHz and is greater than the minimum frequency.

[0053] Field 126 includes coefficients for filtering the control signal output from the controller 96. In many versions of the present invention, the calculation of the VOLTAGE_SET signal and the FREQUENCY_SET signal begins with the calculation of the target values for these signals. Using a PID control loop, the final level for each of these signals is established . Field 126 includes the respective coefficients for these control loops. The fie ld 126 includes the respective coefficients for these control loops. The fie ​​The data in the ludes 112, 116, 118, 120, 122, 124, and 126 is the fee Similar to the data in the lude 114, as part of the process of assembling the handpiece, the hand It should be understood that it is stored in the handpiece memory 58.

[0054] The handpiece memory 58 also includes a field 128 as a usage history field. Control The console 64 writes data to the field 128 in order to provide a log of the operation of the handpiece when the handpiece is in use.

[0055] The operation of the system 30 of the present invention is understood by referring to the flowcharts of FIGS. 6A and 6B. Step 140 represents the initial setting of the system 30. Step 140 includes attaching the tip 48 to the handpiece 32. If the cable 62 is not integrally configured with the handpiece 32, as part of step 140, the cable is connected to the handpiece 32. To connect the handpiece to the console, the cable 62 is connected to the control console 64. Optionally, the foot pedal 104 is attached to the console 64 Before operating the handpiece, the operator positions the switch 106 to set the amplitude of the tip head vibration.

[0056] When the handpiece 34 is connected to the control console 64, in step 142, the console processor 96 reads the data stored in the handpiece memory 58 through the memory reader 102. Any checks that the processor 96 may perform to verify that the console 64 can apply a drive signal to the handpiece 32 are illustrated These checks are not included and are not part of this invention. These checks are based on the data stored in the console. Verify that the product is designed for use with the product and, based on its usage history, and verifying that the handpiece is in working condition. Assuming the source passes these checks, the system 30 is ready for use. be.

[0057] Step 144 is when the processor 94 receives the action from the foot pedal 104 or other control member. indicates that the operator is waiting for a signal indicating that he or she wishes to activate handpiece 32. Before processor 96 received this signal, the processor was 8 does not assert the signal that would output the power signal.

[0058] The practitioner activates the handpiece by depressing the control member. 96, in response to receiving a signal that this event has occurred, in step 148 Current sometimes called target current

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[0059] Thereafter, at step 150, the processor 96 generates and outputs a VOLTAGE_SET signal. First, the VOLTAGE_SET signal is set to output a drive signal that is much smaller than the maximum drive signal voltage obtained from the handpiece memory 58. For example, in some versions of the present invention, this VOLTAGE_SET signal is such that the drive signal has an initial potential

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[0060] As part of step 150, the processor 96 also generates and outputs the FREQUENCY_SET signal. When the control member is first depressed to operate the handpiece, the processor 64 generates the FREQUENCY_SET signal, and based on this signal, the console outputs a drive signal at the initial frequency. This initial frequency can be the lowest possible frequency at which the drive signal should be applied to the handpiece, the highest possible frequency at which the drive signal should be applied, or any frequency between these two limit frequencies.

[0061] Although not specifically mentioned, in step 150, the processor asserts any necessary enable signals for the power supply 68, amplifier 70, and any safety components inside the console. Assertion of these signals ensures that the power supply 68 outputs the required level signals to the amplifier, the amplifier 70 outputs the intended square wave, and the signal from which the drive signal is inductively obtained is applied to the primary winding 78 of the transformer 76.

[0062] As a result of current flowing through the transformer 76, a drive signal is applied to the handpiece 32. As a result, periodic expansion and contraction of the driver 40 occur. This movement of the driver 40 vibrates the tip head 52. In this way, the vibration generated as a result of the execution of step 150 ​ As a result of the bus step, the handpiece 34 is activated. Step 150 is continuously executed until the processor 9 6 determines that the operator desires to stop the handpiece 32, as discussed below.

[0063] Thereafter, the system 30 is involved in a feedback control process to ensure that the output drive signal induces vibrations of appropriate amplitude at the tip head 52. To perform this control, in step 154, the system 96 monitors the voltage V of the drive signal flowing through the handpiece. This is the monitoring of the output signal generated by the voltage measurement circuit 86 by the processor 96. Also, in step 154, the processor 96 monitors the current i S , that is, the current flowing through the handpiece. This is the monitoring of the output signal generated by the current measurement circuit 92. S S

[0064] In step 156, the processor 96 determines the equivalent component of the current applied to the mechanical components of the handpiece, that is, the current

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[0065] In step 158, the current

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[0066] more preferably within 5% of each other, and ideally within 1% of each other, the current can be considered to be substantially the same.

[0066] When the two currents are substantially equal, the system 30 applies to the mechanical components of the handpiece Assuming that the level of the equivalent component of the current to be impressed is at the correct frequency, a drive signal is applied at a level that induces vibrations of an appropriate amplitude at the tip head 52. In this state. When the system 30 is in this state, the processor 96 proceeds to step 164.

[0067] In many situations, the comparison in step 158 indicates that the actual current

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[0068] Then, in step 160, based on this new target value for the drive signal potential the VOLTAGE_SET signal is adjusted and output to the generator 68.

[0069] In step 164, the processor determines whether the drive signal is for the mechanical components of the handpiece Determine whether it is at or substantially equal to the resonant frequency. This determination is made by evaluating whether the ratio of in Equation (11) is equal to or substantially equal to zero. Here , being substantially equal to zero means that Re is 0.10 or less, preferably 0.05 or less , and more desirably 0.01 or less.

[0070] The comparison in Step 164 can indicate that the drive signal applied to the handpiece is at or substantially equal to the resonant frequency of the mechanical components of the handpiece. This is , the target state regarding the drive signal. This means that the drive signal induces expansion and contraction of the driver 40 at a frequency that promotes relatively high-amplitude expansion and contraction. In extension, this results in the tip head operating and relatively large vibrations.

[0071] In the evaluation of Step 164, it may be determined that the drive signal is not applied to the handpiece at or near the resonant frequency of the mechanical components. If the process or 96 makes this determination, in Step 166, the processor resets the frequency of the drive signal. Since the ratio regarding the left side of Equation (11) is negative, the calculation in Step 164 that results in a negative result is interpreted as an instruction from the processor 96 that the frequency of the drive signal should be increased. If the calculation in Step 164 results in a positive result , to ensure that the drive frequency is closer to the resonant frequency of the mechanical components of the handpiece, the processor 96 interprets the result as indicating that the state of the handpiece is such that the drive signal needs to be decreased in frequency.

[0072] Processor 96 resets the frequency of the drive signal applied to the handpiece by adjusting the FREQUENCY_SET signal applied to amplifier 70. Step 1 66, the processor determines the current i , voltage V S , and driver capacitance C S are assumed to be constant. In the iterative process, different frequencies are inserted into equation (11). As a result of the new execution of equation (11), the real component of the ratio of the current through the driver to the equivalent component of the current applied to the mechanical components of the handpiece may be determined to be less than zero (or substantially less than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, processor 166 adjusts the FREQUENCY_SET signal output to amplifier 70 based on the result of this calculation. Thereafter, control console 64 will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. Although not shown, it should be understood that the characteristics of the drive signal applied to handpiece 32 are limited by the limit parameters read from the handpiece. Specifically, V the current through the driver, and the equivalent component of the current applied to the mechanical components of the handpiece may be determined to be less than zero (or substantially less than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, processor 166 adjusts the FREQUENCY_SET signal output to amplifier 70 based on the result of this calculation. Thereafter, control console 64 will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, the processor will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. the current through the driver, and the equivalent component of the current applied to the mechanical components of the handpiece may be determined to be less than zero (or substantially less than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, processor 166 adjusts the FREQUENCY_SET signal output to amplifier 70 based on the result of this calculation. Thereafter, control console 64 will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, the processor will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this state occurs, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, the processor will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece.

[0073] Although not shown, it should be understood that the characteristics of the drive signal applied to handpiece 32 are limited by the limit parameters read from the handpiece. Specifically, V the current through the driver, and the equivalent component of the current applied to the mechanical components of the handpiece may be determined to be less than zero (or substantially less than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be higher than the previously inserted frequency. As a result of the execution and evaluation of equation (11), the ratio may be determined to be greater than zero (or substantially greater than zero). If this is the case, then in the subsequent iteration, the frequency to be inserted will be lower than the previously inserted frequency. As a final result of this calculation, when the ratio is zero or substantially zero, the frequency of the drive signal is set to the inserted frequency. Thereafter, processor 166 adjusts the FREQUENCY_SET signal output to amplifier 70 based on the result of this calculation. Thereafter, control console 64 will then output a drive signal at the resonant frequency of the mechanical components of handpiece 32 to the handpiece. The adjustment of the VOLTAGE_SET signal is limited to ensure that the drive signal does not exceed the potential defined by the maximum voltage level

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[0074] In FIGS. 6A and 6B, after the execution of step 160, or step 164 if necessary, the system is shown to loop back to step 144. This is because the processes of recalculating the target current

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[0075] There are several reasons why the control loop is repeatedly executed. Generally, as a result of the adjustment, if the frequency of the drive signal is adjusted, it should be understood that both the driver impedance Z O and the impedance Z of the mechanical components of the handpiece M will change. As a result, the current through the handpiece, more specifically, the current through the mechanical components of the handpiece

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[0076] Similarly, as a result of adjusting the potential of the drive signal, changes in the voltage V S and the voltage i S also occur . This means that at the next time step 164 is executed, the evaluation indicates that the drive signal is no longer at the resonant frequency of the mechanical components of the handpiece. This means that at the next time step 164 is executed, the evaluation indicates that the drive signal is no longer at the resonant frequency of the mechanical components of the handpiece.

[0077] After circulating through the control loop several times, the console 64 asserts the drive signal, and as a result, the current passing through the mechanical components of the handpiece becomes substantially equal to

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[0078] Another reason for continuously executing the control loop is related to the very nature of how the handpiece 32 is used. For the handpiece to function, the head 52 is applied to the tissue This is related to the very nature of how the handpiece 32 is used. For the handpiece to function, the head 52 is applied to the tissue is arranged in contact therewith (steps not shown). This is because, as a result of the back-and-forth movement of the teeth in contact with the tissue, the tissue is sawed, i.e., removed. Here too, in several embodiments of the present invention, as a result of this back-and-forth movement, cavitation is caused in the body fluid adjacent to the tissue and, in some cases, in the tissue itself. This is because, as a result of the back-and-forth movement of the teeth in contact with the tissue, the tissue is sawed, i.e., removed. Here too, in several embodiments of the present invention, as a result of this back-and-forth movement, cavitation is caused in the body fluid adjacent to the tissue and, in some cases, in the tissue itself.

[0079] When the head is arranged in contact with the tissue, a mechanical load is applied to the components forming the handpiece. This mechanical load changes the impedance of the mechanical load of the handpiece. Also, when the system 30 is operating, the temperature of the mechanical components of the handpiece changes in many cases. This change in the component temperature causes a change in the characteristics of these components. When the characteristics of the components change, the target frequency may shift. These shifts in the characteristics of the mechanical components of the handpiece are represented in FIG. 7 by the respective changes in inductance L M , resistance R M and capacitance C . M are represented in FIG. 7 by the respective changes in inductance L, resistance R and capacitance C.

[0080] As a result of the change in impedance and resonance frequency, as a result, changes occur in both the flow of current i through the handpiece S and the flow of current

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[0081]

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[0082] Therefore, the above control loop starting from the evaluation in step 144 is continuously executed as long as the foot pedal 10 4 or other on / off control remains activated. The operator stops the handpiece by releasing the foot pedal 104. As a result, the program In any subsequent execution after step 144, the processor receives a signal indicating that this control member is at the off position. In response to the processor 96 receiving this signal, , the processor negates the application of the signal that was being asserted to output a drive signal. This step is not shown. The system 30 returns to the standby state and continuously monitors the signal from the on-off control member to determine whether the operator desires to actuate the hand piece 32.

[0083] By repeatedly executing steps 164 and 166, the system 30 of the present invention is configured such that the system maintains the drive signal at a frequency substantially equal to the resonance frequency of the mechanical components of the handpiece 32. This relationship is maintained even when the resonance frequency of the mechanical components of the handpiece changes due to the mechanical load and / or temperature change of these components. Therefore, the system of the present invention can vibrate the tip head at a desired amplitude even when the tip of the handpiece and other components are subjected to mechanical load or temperature change. This reduces the need for the surgical personnel using the system to continuously adjust the drive signal to ensure that the tip head vibrates continuously at the desired amplitude. / or when the resonance frequency of the mechanical components of the handpiece changes due to temperature change.

[0084] Also, during a procedure, the tip head may suddenly be pressed against tissue. This rapidly and significantly increases the impedance of the mechanical components of the handpiece. In response to this rapid impedance change, the system 30 of the present invention rapidly adjusts the potential and frequency of the drive signal. The adjustment of these characteristics of the drive signal ensures that the tip head vibration is at the desired amplitude. It plays a role in ensuring the retention of the amplitude. This is to suppress the degree to which the amplitude of the tip head vibration suddenly decreases as a result of a mechanical load suddenly being applied to the handpiece. .

[0085] A further feature of the system 30 is that the system does not track a specific phase relationship between the voltage and current of the drive signal. Instead, the system 30 tracks the phase of the equivalent component of the drive signal applied to the mechanical components of the handpiece. For the reasons explained above, this ensures that the supplied drive signal has the characteristic of maintaining the mechanical resonance of the handpiece. .

[0086] The system 30 of the present invention is further configured such that the control of the handpiece is not based on matching the capacitance, resistance, or inductance of components inside the control console to the characteristics of the handpiece. This means that the system 30 of the present invention can be configured with another handpiece having a unique driver capacitance using a single console 64. The console configures the system for each handpiece based on the data read from the handpiece memory 58 representing the driver capacitance. Similarly, one handpiece can be used with a plurality of different control consoles when assembling the system 30 of the present invention. .

[0087] The system 30 of the present invention is further designed to apply an equivalent component of current substantially equal to the target current to the mechanical components of the handpiece. This target current is based on the operator setting the desired amplitude of the tip head vibration. Therefore, the system of the present invention ​​​​​​​​​​​​Provide the operator with a relatively accurate means of controlling the amplitude of the tip head vibration.

[0088] [IV. First Alternative Method of Drive Signal Frequency Control] In an alternative configuration of the system 30 of the present invention, the target frequency of the drive signal is set to the anti-resonant frequency of the mechanical components of the handpiece. The anti-resonant frequency is the frequency at which the impedance of the handpiece 32 is maximum. Ideally, this approaches infinity. In this version of the present invention, in step 164, the real component of the ratio of the current supplied to the piezoelectric driver 40 to the equivalent component of the current applied to the mechanical components of the handpiece 32 is evaluated as follows.

[0089] [Equation]

[0090] If, as a result of the evaluation in step 164, the ratio is not substantially equal to 1, the processor, in step 166, enters a different frequency into equation (13). This process continues until the processor determines a frequency that is substantially equal to 1. This frequency is the anti-resonant frequency. Thereafter, the processor outputs a FREQUENCY_SET signal, and as a result of that signal, the control console supplies a drive signal at this frequency.

[0091] In another version of the present invention, the processor 96 can evaluate the real component of the ratio of the current supplied to the piezoelectric driver 40 to the equivalent component of the current applied to the mechanical components of the handpiece 32 in order to obtain a target frequency that is different from the resonant frequency or the anti-resonant frequency. Thus, the evaluation can be made for values between 0 and 1, and even for values greater than 1. ​​​​​​​​​​​ 。

[0092] [V. Alternative Second and Third Methods of Driving Frequency Control] Regarding some configurations of the system 30 of the present invention, the circuit of FIG. 4B shows the impedance of the mechanical components that make up the handpiece in a highly simplified manner. In this version of the present invention, as shown in FIG. 8, mathematically, some ultrasonic tool mechanical components can be regarded as having a plurality of RLC series-connected circuits connected in parallel with each other. This means that these components have a plurality of frequencies at which they resonate within a certain frequency range. Here, the reactive component of the impedance is 0. The impedance Z of this type of handpiece 32 and tip 48 is expressed as follows. and tip 48 is expressed as follows. H is expressed as follows.

Equation

Equation

[0093] When these multiple resonance frequencies are within the frequency range of the drive signal to be applied to the handpiece, difficulties may occur when applying the drive signal to this type of handpiece and tip assembly. The nature of this problem can be understood by referring to FIG. 9. Here, plot 182 shows the handpiece when the tip is operating in air. The nature of this problem can be understood by referring to FIG. 9. Here, plot 182 shows the handpiece when the tip is operating in air. When the tip is operating in air, the ​It represents the reactance of the mechanical components over a certain frequency range. The driving signal is 25 .20kHz to 25.65kHz range, i.e., the two thick vertical lines 181 and 183. Within this frequency range, The reactance component of the mechanical impedance is a resonant impedance at about 25.54 kHz. The reactance of the handpiece is about 25.86k. Hz, it passes through a point of zero reactance outside the range of the driving frequency. However, the second time The only thing passing through is the mechanical reactor because it is outside the range where the control console 64 applies the drive signal. The fact that the impedance is zero at this frequency does not affect the operation of the system.

[0094] Plot 184 shows the relationship between frequency and the tip as it is pressed against a load during vibration. This load represents the change in reactance of the mechanical components of the handpiece. is understood to be the tissue that is intended to be removed. As discussed above, As a result, the equivalent resistance and reactance of the mechanical components that make up the handpiece change. The reactance at a given frequency changes from plot 182 to plot 184. Here, the mechanical components of the handpiece are adjusted to the frequency range in which the drive signal is applied. The equivalent reactance of the reactor is twice as large at 25.30 kHz and 25.45 kHz. It can be seen that the path may pass through a point with zero impedance.

[0095] For a particular handpiece and tip assembly to function most efficiently, there are usually two Applying a drive signal at or near the lower resonant frequency This is desirable. Therefore, this lower frequency of the two resonance frequencies is the target frequency At a given point in time when step 164 is executed, the result of the evaluation of step 164 is

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[0096] To reduce the possibility of the events identified above from occurring, in some versions of the present invention the system selectively adds a virtual impedance X to the impedance of the mechanical components of the handpiece. Diagrammatically, as seen in FIG. 10, the virtual i adj mpedance X is considered to exist in series with the mathematical model of the impedance of the mechanical components of the handpiece. adj

[0097] FIG. 11 shows the effect of adding this virtual impedance to the impedance of the mechanical components of the handpiece. In FIG. 11, plot 184 is the same plot of the reactance of the mechanical components of the handpiece when a load is applied to the tip as shown in FIG. 9. Plot 185 is the reactance of the virtual impedance X adj ance component​​​​​​ is minutes. Here, the reactance component of the virtual impedance is assumed to be 0 at the frequency where the reactance of the mechanical components of the handpiece is 0. Plot 186 is the sum of the reactances of Plot 184 and 186. As shown in Plot 186, when the virtual impedance is added to the mechanical reactance, the total reactance passes through 0 only once in the frequency range where the drive frequency will be applied.

[0098] FIG. 12 is a partial block diagram of an alternative component of one version of the present invention designed to add a virtual impedance to the actual impedance of the mechanical components of the handpiece. The handpiece 190 represented by the rectangle has a mechanism similar to the handpiece 32 described above. These mechanisms include conductive sockets or other contacts 196 and 19 8 for supplying a drive signal to the driver 40 inside the handpiece. The drive signal is supplied from pins or other conductive contacts 188 and 189 configured integrally with the control console socket to which the handpiece is connected. For ease of illustration, the cable 62 is not shown in FIG. 12.

[0099] A specific memory 58 inside the handpiece 190 is an RFID tag. Since the memory 58 is an RF ID tag, it is also shown inside the handpiece 190, and connected to the memory 58 is a coil or antenna 202. The coil 202 is understood to be at the end of a cable connected to the control console socket. The coil 202 is configured to inductively exchange signals with a complementary coil 187 disposed within the console socket, and the position ​​​​​​​​​​​​It has been determined. Although not shown, the console coil 187 is connected to the console memory reader 102. The memory reader 102 converts the signal received via the coil 187 into a signal that can be read by the processor 96. Also, the memory reader 102 outputs the data that the processor 96 wants to write to the memory to the handpiece memory 58.

[0100] The second coil, that is, the coil 206, is also disposed within the handpiece 190. The coil 202 is normally located adjacent to the proximal end of the handpiece 190, while the coil 206 is located adjacent to the distal end. More specifically, the coil 206 is positioned to exchange signals with the sleeve coil 212 discussed below. The conductor 204 within the handpiece 190 connects the coil 202 to the coil 206.

[0101] The sleeve 55 is represented as the tapered unit in FIG. 12. The tip portion 48 extends from this sleeve 55. The tip memory 214 is disposed within the sleeve 55. Even when the memory 214 is within the sleeve 55, the memory 214 is called the "tip memory" for two reasons. First, the tip portion 48 and the sleeve 55 are separate components but are usually packaged together as one kit. Second, the data contained in the memory 55 is mainly used to control the operation of the tip portion 48. The coil 212 incorporated in the sleeve 55 is connected to the tip memory 55.

[0102] FIG. 13 shows some of the data stored in the tip memory 214. The tip ​​​​​​​​​​​​​The end identification data field 218 contains tip identification data similar to the handpiece identification data within field 112. There are a minimum current field 220 and a maximum current field 22 4. Fields 220 and 222 contain data indicating the range of the equivalent components of the current to be applied to the mechanical components of the handpiece with respect to a particular tip to which the memory 214 is associated . There is a maximum voltage field 224 similar to the maximum voltage field 120 within the handpiece memory. There are drive frequency fields 226 and 228. The data within fields 22 6 and 228 respectively define a tip-specific frequency range for the drive signal, which may be different from the frequency range of the handpiece drive signal defined in the minimum drive frequency field 122 and the maximum drive frequency field 124 of the handpiece memory. The PID coefficient field 230 contains filtering coefficients for the control signal and may be more precise than the data in the handpiece PID coefficient field 126 with respect to the tip . The tip usage history field 232 contains data regarding the use of the tip. The console processor 96 can write data to field 232 through the memory reader 102 . Also, the tip memory also includes a target frequency field 234 and an impedance adjustment coefficient field 236. The target frequency field 234 contains data representing a frequency ω within the frequency range of the drive signal applied to the handpiece . More specifically, the frequency ω is the frequency within the drive frequency range of the handpiece at which the mechanical reactance is minimized when a load is applied to the tip. The load to which the tip is exposed is determined by the procedure

[0103] target target ​​​​​​​​​ It is to be understood that this is different, and within a single procedure, it is also different. This is because, depending on the procedure, and within a single procedure, the frequency at which the mechanical reactance of the handpiece reaches its minimum point is not constant. Therefore, the frequency ω target is the frequency within the normally expected range where the reactance minimum point is predicted for that handpiece load. The coefficient field 236 includes the above coefficient m that defines the change in reactance with respect to frequency.

[0104] The system of the present invention to which the handpiece 190 is attached is driven in substantially the same manner as the handpiece 32 is driven. Nevertheless, there are several differences in the process steps as outlined in FIGS. 6A and 6B. In step 142, the control processor 96 does more than simply read the data in the handpiece memory 58. Also, in step 142, the control processor reads the data in the tip memory 214.

[0105] Based on the data in the handpiece memory 58 and the tip memory 214, the processor Based on this data, the step of determining whether the system can vibrate the tip 48 is not shown. Data indicating that the system is not suitable for vibrating the tip includes data indicating that the tip has been used beyond its designed lifespan. Other data indicating that the system should not vibrate the tip includes identification data from the handpiece and the tip, indicating together that the tip is not intended to be vibrated by the handpiece. Whether the system can drive the tip in the current configuration If it is not suitable for driving, usually, the control processor 96 causes the console to display on the display 108 information indicating why the drive signal is not supplied to the handpiece 190. In some versions of the present invention, this information is presented only as a warning. After this information is presented, the operator is still given the opportunity to operate the handpiece. In some versions of the present invention, this information is presented only as a warning. After this information is presented, the operator is still given the opportunity to operate the handpiece. In some versions of the present invention, this information is presented only as a warning. After this information is presented, the operator is still given the opportunity to operate the handpiece.

[0106] In step 148, the processor 94 sets the target current based on the maximum current value obtained from the tool memory 214. The frequency range of the drive signal can also be set based on the frequency range obtained from the memory 214. In step 148, the processor 94 sets the target current based on the maximum current value obtained from the tool memory 214. The frequency range of the drive signal can also be set based on the frequency range obtained from the memory 214.

Number

[0107] Further changes regarding how to determine the characteristics of the drive signal occur when step 164 is performed. In this version of the present invention, the control processor 96 does not use the evaluation of equation (11) to determine whether the mechanical components of the handpiece are resonating. Instead, the processor uses the following equation to evaluate whether the mechanical components of the handpiece are resonating. Further changes regarding how to determine the characteristics of the drive signal occur when step 164 is performed. In this version of the present invention, the control processor 96 does not use the evaluation of equation (11) to determine whether the mechanical components of the handpiece are resonating. Instead, the processor uses the following equation to evaluate whether the mechanical components of the handpiece are resonating. Further changes regarding how to determine the characteristics of the drive signal occur when step 164 is performed. In this version of the present invention, the control processor 96 does not use the evaluation of equation (11) to determine whether the mechanical components of the handpiece are resonating. Instead, the processor uses the following equation to evaluate whether the mechanical components of the handpiece are resonating. Further changes regarding how to determine the characteristics of the drive signal occur when step 164 is performed. In this version of the present invention, the control processor 96 does not use the evaluation of equation (11) to determine whether the mechanical components of the handpiece are resonating. Instead, the processor uses the following equation to evaluate whether the mechanical components of the handpiece are resonating. Further changes regarding how to determine the characteristics of the drive signal occur when step 164 is performed. In this version of the present invention, the control processor 96 does not use the evaluation of equation (11) to determine whether the mechanical components of the handpiece are resonating. Instead, the processor uses the following equation to evaluate whether the mechanical components of the handpiece are resonating.

Number

[0108] For the real component of the reactance of the mechanical component of the reactance within the frequency range of the drive signal If there are multiple zero crossings, by including the virtual impedance in the evaluation of step 164 it is ensured that the evaluation still indicates whether the drive signal needs to be lowered or raised with respect to the desired resonance frequency. In this way, when using the example of plot 186, if this version of the evaluation of step 164 shows a negative result it clearly means that the frequency must be increased to drive the signal into resonance. Similarly, if the evaluation shows a positive result, the frequency of the drive signal must clearly be lowered .

[0109] This version of the present invention is also useful when the operator desires to first place the distal head 52 in contact with the tissue and then activate the handpiece 32. In this situation the handpiece and the distal end are already loaded when activated. Due to its mechanical characteristics, some distal ends have the property that when starting with a load applied, the load resistance immediately attenuates the vibration to a level where there is basically no vibration. When the handpiece and the distal end are in that state, the system can basically be regarded as being in a stalled state . When the system is in this state, the reactance of the mechanical components of the handpiece resistance is such that when starting with a load applied, the load resistance immediately attenuates the vibration to a level where there is basically no vibration. When the handpiece and the distal end are in that state, the system can basically be regarded as being in a stalled state . When the handpiece and the distal end are in that state, the system can basically be regarded as being in a stalled state and when the system is in this state, the reactance of the mechanical components of the handpiece The reactance is basically constant over the drive frequency range. Basically, the mechanical resistance component of the impedance is significantly larger than the mechanical equivalent components of the inductive and capacitive impedances. This means that, for example, as shown by Plot 184, if there is a change in reactance with frequency, detection is difficult.

[0110] In this way, in the version of the present invention in which such a state exists, the adjustment part of the above formula (16 ) becomes the main component of the ratio that changes with frequency. Therefore, even if the handpiece and the tip stall, when the processor executes Step 164, it will still obtain some information regarding how close the drive frequency is to the drive frequency required to drive the tip at the resonance frequency of the loaded state. In fact, what usually happens when the system is in this state is that the processor increases the frequency of the drive signal. By increasing the frequency of the drive signal in this way, the handpiece driver and the tip vibrate at the frequency at which the handpiece exits the stalled state.

[0111] It should be understood that it may not be necessary to consider the virtual impedance for all tips that may be incorporated into the system of the present invention. In the case of such tips that do not require such adjustment, the impedance adjustment coefficient m is set to 0. As a result, formula (15) is simplified to formula (11 ) .

[0112] In a fourth alternative version of the present invention, this additional virtual impedance is used so that the drive signal is at the anti-resonance frequency of the impedance of the mechanical components of the handpiece. As such, the setting of the drive signal frequency is regulated. Thus, Equation (13) and Equation ( 15) are combined as follows. [Number]

[0113] In yet another version of the present invention, the modified ratio on the left side of Equation (15) and Equation (16) can be compared with a target ratio representing a frequency between the resonance frequency and the anti-resonance frequency.

[0114] [VI. Fourth Alternative Means of Drive Frequency Control] In yet another version of the present invention, only the frequency of the drive signal is adjusted. In this version of the present invention, the frequency of the drive signal is near or at the resonance frequency of the mechanical components of the handpiece and is adjusted to apply a drive signal at a desired target or near current level with respect to the equivalent component of the current to be applied to the mechanical components of the handpiece.

[0115] This version of the present invention is understood by referring to the flowcharts of FIGS. 15A and 15B. In this version of the present invention, steps 140, 142, 144, 148, and 154 are executed substantially in the same manner as described above with respect to the process shown in the flowcharts of FIGS. 6A and 6B. In this version of the present invention, when the handpiece is first activated, step 150A, which is an alternative to step 150 described above, is executed when the handpiece is first activated. In step 150A, the processor 96 represents the VOLTAGE_SET signal, which represents the highest voltage to be applied to the handpiece. Outputs the number. Also, the processor 96 generates a FREQUENCY_SET signal and outputs it. The same process used to determine the initial FREQUENCY_SET signal in step 150 is used in step 150A to output the same signal in step 150A.

[0116] After step 154 is executed, in this method of the present invention, in step 252, the processor calculates the ratio of the current passing through driver 40 to the equivalent current passing through the mechanical components of the handpiece, that is, the ratio on the left side of equation (11). In step 254, this ratio is compared with the target ratio (TF). In the initial state, the target ratio is a scalar value representing the desired target frequency of the drive signal for the mechanical components of the handpiece. For example, if it is desired to drive the mechanical components of the handpiece at the resonance frequency, the initial target ratio is 0 (zero). If it is desired to drive the mechanical components of the handpiece at the anti-resonance frequency, the initial target ratio is 1 (unity). The initial target ratio may be between these values. This applies when it is desired to drive the tip at a frequency at which the mechanical components of the handpiece have a responsiveness between the responsiveness at the resonance frequency and the responsiveness at the anti-resonance frequency.

[0117] Based on this comparison, if necessary, in step 256, the frequency of the drive signal is selectively reset. This analysis and reset operation of the FREQUENCY_SET signal is similar to the analysis and frequency reset operations of steps 164 and 166.

[0118] ​​​​​​​​​​After step 254 and, if necessary, step 256 are executed, at step 25 8, the processor determines an equivalent current through the mechanical components of the handpiece, i.e., current

number

number

[0119] If the calculated current is relatively close to the target current, the processor 96 determines that the system is in a situation where the drive signal is at a frequency substantially equal to the desired target frequency for the mechanical components of the handpiece and the equivalent current through these components is substantially equal to the target of this equivalent component of the current. If the system is in this state, the processor loops back to step 144. This loopback is similar to the loopback to step 144 that is executed after step 164 or step 166 is executed Step 34 is similar to the loopback to step 144 that is executed after step 164 or step 166 is executed

[0120] As a result of executing step 260, it may be determined that there is a significant difference between the calculated current and the target current In many situations, this is because the calculated current is higher than the target current If the system of the present invention is in this state, at step 262 the processor adjusts the value of the target ratio. This new ratio is TR ADJ which is the target As a result of the subsequent resetting of the drive frequency away from the drive frequency, the mechanical This is because a similar reduction occurs in the equivalent component of the current applied to the objective component.

[0121] In step 264, the equivalent components of the current through the mechanical components of the handpiece are calculated. The ratio of the currents through the drivers is compared to a regulated target ratio. This will show that the actual ratio is significantly different from the adjusted target ratio. The processor then adjusts the FREQUENCY_SET signal in step 266. The FREQUENCY_SET signal controls the current applied to the mechanical components of the handpiece. is needed to reset the equivalent component of The initial target current and the adjusted target current are reset so that the new drive signal is closer to the If the difference from the target current is small, step 266 may not be performed.

[0122] After performing step 264, and often after performing step 262 Then, processor 96 loops back to execution of step 144.

[0123] This version of the invention allows for a frequency that is close to the desired target frequency for the handpiece. and the equivalent component of the current applied to the mechanical components of the handpiece is this current The result is a drive signal that is close to the target for the drive signal without the need to set the potential of the drive signal. The blood is delivered to the handpiece without any need for a special device.

[0124] VII. ALTERNATIVE OR ADDITIONAL MEANS OF OBTAINING DRIVER CAPACITANCE In another version of the invention, the control console 64 includes at least one piezoelectric actuator. Driver capacitance C O There are circuits that can measure the The capacitance is obtained by outputting a drive signal that is swept over a wide range. During this period, the V S and i S Based on these data, the processor 96 determines the driver capacity. Citans C O is mathematically calculated.

[0125] The system 30 of the present invention handles a memory having data representative of the driver capacitance. A process is carried out to determine this capacitance so that it is not necessary to provide a In these versions of the invention, the system may be configured to As part of the initial setup of the system, driver capacitance is determined. .

[0126] The system associates data representing the capacitance value of the driver with the handpiece. Even if the driver capacitance can be obtained from the memory, the system 30 There is also a reason to have this function of asking for One reason it is desirable to have the stem perform this process is because Specifically, the system performs this step and determines the state of the process. The determined value of the driver capacitor generated by the sensor and the value obtained from the handpiece memory The capacitance value thus obtained is compared with the capacitance value obtained in step 142. If these capacitance values are not substantially equal, The sensor interprets this difference as an indication that the handpiece may be in a malfunction state. This malfunction may occur due to some type of damage to the driver. At that time, the processor asserts a message indicating that the handpiece may not be functioning properly. The practitioner can use this information to determine whether it is appropriate to proceed with the procedure using this particular handpiece. In any configuration of the present invention, the system can be further configured to request the driver capacitance even after the procedure has started. As mentioned above, the driver capacitance is substantially constant for the purpose of supplying a drive signal according to the present invention. Nevertheless, during the procedure, a situation may occur where the driver capacitance may change over time. For example, if the handpiece is used for a long time, say, for more than 10 minutes, the handpiece including the driver 40 may be subjected to heat generation induced by friction. This heat generation is the result of the repeated expansion and contraction of the driver 40. As a result of the temperature change of the handpiece, the driver capacitance may change. Therefore, even when the initial capacitance is read from the handpiece memory 58, the system may periodically execute a process for requesting the driver capacitance. In this configuration of the present invention, when the obtained driver capacitance is within the previously set capacitance range, the processor 96 uses this newly obtained driver capacitance.

[0127] In any configuration of the present invention, the system can be further configured to request the driver capacitance even after the procedure has started. As mentioned above, the driver capacitance is substantially constant for the purpose of supplying a drive signal according to the present invention. Nevertheless, during the procedure, a situation may occur where the driver capacitance may change over time. For example, if the handpiece is used for a long time, say, for more than 10 minutes, the handpiece including the driver 40 may be subjected to heat generation induced by friction. This heat generation is the result of the repeated expansion and contraction of the driver 40. As a result of the temperature change of the handpiece, the driver capacitance may change. Therefore, even when the initial capacitance is read from the handpiece memory 58, the system may periodically execute a process for requesting the driver capacitance. In this configuration of the present invention, when the obtained driver capacitance is within the previously set capacitance range, the processor 96 uses this newly obtained driver capacitance.

[0128] In this configuration of the present invention, when the obtained driver capacitance is within the previously set capacitance range, the processor 96 uses this newly obtained driver capacitance. ​​​​​​​​​​​​Use the cabinet as a variable driver capacitance C O to set the characteristics of the drive signal. How ever, there may also be a situation where the newly required driver capacitance is outside the setting range of the previous driver capacitance. The processor 96 can be set to interpret the system 3 0 in this state as an indication that the handpiece 32 is in a malfunction state. When the processor 96 makes this determination, the processor causes a message indicating that the handpiece may be in this state to be displayed.

[0129] [VIII. Alternative Model of the Impedance of the Mechanical Components of the Handpiece] In an alternative configuration of the present invention, the model of the current applied to the driver 40 and the equivalent component of the current applied to the mechanical components of the handpiece can be based on alternative models of the resistance, inductance, and capacitance of these components.

[0130] FIG. 14 shows one alternative model of the arrangement of the components of the handpiece that give impedance to the current and the equivalent applied current. In this model, the capacitance has two components, namely, a combined capacitance C and a blended capacitance C A and a blended capacitance C X Each of these capacitances is a function of both the driver capacitance and the equivalent capacitance of the mechanical components of the handpiece 40, as represented by equations ([[]] 14) and (15).

Equation

Equation

Equation

[0131] This means that the impedance of the handpiece, the equivalent component of the current applied to the mechanical components of the handpiece and the real component of the ratio of the equivalent current flowing through the mechanical components of the handpiece will change in the same way when used to calculate it.

[0132] Furthermore, although not shown, in other models of the equivalent impedance of the mechanical components of the handpiece, it should be understood that two of the three components contributing to the impedance, namely resistance, inductance or capacitance, may exist in parallel with each other. In this model, the third component exists in series with the two parallel components.

[0133] [IX Additional alternative version] The above relates to a specific version of the present invention. Some versions of the present invention may have mechanisms different from those described. For example, different versions of the present invention The above mechanisms can be combined.

[0134] The structural features of the present invention may also be different from those described. For example, the post on which the driver is arranged can be processed using a horn. Similarly, other means can be used to measure the voltage applied to the handpiece and the current flowing through the handpiece. Therefore, instead of an inductor, a resistor can also be used to perform this signal detection. In some versions of the present invention, there may be no insulating disk between adjacent drivers. There may be an insulating element between the closest driver and the mass 36, or between the driver and the horn. The number of drivers may be less than or more than the number of disclosed drivers. In some versions of the present invention, there may be no insulating disk between adjacent drivers. There may be an insulating element between the closest driver and the mass 36, or between the driver and the horn. The number of drivers may be less than or more than the number of disclosed drivers. In some versions of the present invention, there may be no insulating disk between adjacent drivers. There may be an insulating element between the closest driver and the mass 36, or between the driver and the horn. The number of drivers may be less than or more than the number of disclosed drivers. In some versions of the present invention, there may be no insulating disk between adjacent drivers. There may be an insulating element between the closest driver and the mass 36, or between the driver and the horn. The number of drivers may be less than or more than the number of disclosed drivers. In some versions of the present invention, there may be no insulating disk between adjacent drivers. There may be an insulating element between the closest driver and the mass 36, or between the driver and the horn. The number of drivers may be less than or more than the number of disclosed drivers.

[0135] In some versions of the present invention, a signal foot pedal or hand switch is a control member used to control both the on / off state of the handpiece and the magnitude of the drive signal applied to the handpiece. In some versions of the present invention, a signal foot pedal or hand switch is a control member used to control both the on / off state of the handpiece and the magnitude of the drive signal applied to the handpiece. In some versions of the present invention, a signal foot pedal or hand switch is a control member used to control both the on / off state of the handpiece and the magnitude of the drive signal applied to the handpiece.

[0136] Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Similarly, the electrical components of the system may be different from those described. For example, some versions of the control console may not include a class D amplifier. In one alternative version of the present invention, the signal output from the power supply is output to a class A amplifier. In one embodiment of this version of the present invention, the processor 96 still outputs a VOLTAGE_SET signal to the power supply 68 to establish the peak voltage of the drive signal. Also, the processor 68 outputs a variable frequency positive Outputs a sine wave signal. Based on this FREQUENCY_SET signal, the amplifier selectively amplifies the signal from the power supply so as to supply a drive signal having a desired frequency. In yet another embodiment of this version of the present invention, the power supply outputs a DC signal of a fixed potential. The processor outputs a sine wave that varies with respect to both frequency and peak-to-peak voltage. In this way, this signal is a synthesized VOLTAGE_SET signal and a FREQUENCY_SET signal. This sine wave is applied to the amplifier. Based on this signal, the amplifier selectively amplifies a constant signal from the power signal to generate a selected drive signal. In these versions of the present invention, it may not be necessary to filter the drive signal output by the amplifier before supplying the signal to the handpiece 32. The steps in the process may be performed in a sequence different from that described. Thus, with respect to the version of the present invention described with reference to the flowcharts of FIGS. 6A and 6B, the system can be configured to adjust the frequency of the drive signal before adjusting the voltage of the drive signal. In the version of the present invention described with reference to FIGS. 15A - 15C, one of the comparisons of the ratio of the current through the driver 40 to the equivalent component of the current applied to the mechanical component of the handpiece with respect to the target frequency can be omitted. In this version of the present invention, as a result of performing steps 260 and 262, it is understood that this ratio is compared with the target ratio that is being adjusted in most cases. Similarly, the control algorithm may be changed. For example, supplied to the handpiece driver 40

[0137]

[0138] ​​​​​​​​​​​​​​The ratio between the given current and the equivalent component of the current applied to the mechanical components of the handpiece The components of the algorithm used to change the are not necessarily the first-order difference between the target frequency and the actual frequency. In some versions of the present invention, the second- or even higher-order differences between these frequencies are used to generate components that change the basic ratio. In other versions of the present invention, within a first range of differences with respect to frequency, the component is based on a certain order of the differences with respect to these frequencies. Within a second range of differences with respect to these frequencies, the component is based on a second order of the differences with respect to frequency. Similarly, in some versions of the present invention, the component over a certain range of differences with respect to frequency is based on a certain order of the differences with respect to frequency. In this version of the present invention, the coefficients used to obtain the changing component may vary depending on the differences with respect to frequency. Therefore, the appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the present invention.

[0139] ​​​

Claims

1. a control console for vibrating a tip of an ultrasound instrument, comprising: the ultrasonic instrument having at least one driver to which an AC drive signal is applied to vibrate the tip, and at least one memory device that stores data indicative of a capacitance of the at least one driver of the ultrasonic instrument; an assembly for generating the AC drive signal applied to the at least one driver of the ultrasonic device; a processor connected to said assembly; Equipped with The processor: reading data indicative of a capacitance of the at least one driver from the at least one memory device of the ultrasound machine; determining a frequency corresponding to a target frequency of vibration of a mechanical component of the ultrasonic device based on the capacitance indicated by the read data; setting a frequency of the AC drive signal applied to the at least one driver based on the determined frequency. Control console.

2. The processor: determining a second capacitance of the at least one driver by setting a frequency and a voltage of the AC drive signal after setting a frequency of the AC drive signal based on the determined frequency; determining a second frequency corresponding to a target frequency of vibration of a mechanical component of the ultrasonic device based on the second capacitance; setting a frequency of the AC drive signal based on the determined second frequency; The control console of claim 1 .

3. The processor: comparing the second capacitance to the capacitance indicated by the read data; setting a frequency of the AC drive signal based on the determined second frequency if the comparison indicates that the second capacitance is within a threshold of the capacitance indicated by the read data.

3. The control console of claim 2.

4. The processor: Calculating an equivalent current equivalent to a current applied to a mechanical component of the ultrasonic device based on the capacitance indicated by the read data; determining a frequency corresponding to a target frequency of vibration of a mechanical component of the ultrasonic device based on the calculated equivalent current; A control console according to any one of claims 1 to 3.

5. The processor: determining a voltage level corresponding to a target amplitude of vibration of the tip portion based on the calculated equivalent current; setting a voltage level of the AC drive signal applied to the at least one driver based on the determined voltage level.

5. The control console of claim 4.

6. a transformer having a primary winding, a secondary winding in which the AC drive signal is induced by a signal applied to the primary winding, and a coil for measuring the voltage of the AC drive signal; the processor calculates the equivalent current to be applied to a mechanical component of the ultrasonic device based on the capacitance indicated by the retrieved data and the voltage of the AC drive signal measured by the coil of the transformer; 5. The control console of claim 4.

7. the at least one memory device of the ultrasound machine stores data indicative of PID coefficients for adjusting the AC drive signal; The processor: reading data indicative of the PID coefficients from the at least one memory device of the ultrasound machine; setting a frequency of the AC drive signal based on the PID coefficient indicated by the read data and the calculated frequency; A control console according to any one of claims 1 to 3.

8. 8. The control console of claim 7, wherein the processor sets a voltage level of the AC drive signal based on the PID coefficients indicated by the read data.

9. The processor: determining a voltage level corresponding to a target amplitude of vibration of the tip portion based on the capacitance indicated by the read data; setting a voltage level of the AC drive signal applied to the at least one driver based on the determined voltage level. A control console according to any one of claims 1 to 3.

10. 1. A method for adjusting an AC drive signal supplied from a control console to an ultrasonic device to vibrate a tip of said ultrasonic device, comprising: the ultrasonic instrument comprising at least one driver to which the AC drive signal is applied to vibrate the tip, and at least one memory device that stores data indicative of a capacitance of the at least one driver; the control console reading data indicative of a capacitance of the at least one driver from the at least one memory device of the ultrasound machine; determining, by the control console, a frequency corresponding to a target frequency of vibration of a mechanical component of the ultrasonic device based on the capacitance indicated by the read data; the control console setting a frequency of the AC drive signal applied to the at least one driver based on the determined frequency; A method comprising:

Images