System and method for driving ultrasonic type handpiece by using linear amplifier

Abstract

To provide an ultrasonic type tool system including a console capable of outputting a drive signal at a wide range of frequency and a wide range of voltage.SOLUTION: Provided is a control console 50 for a motor-driven surgical tool 330. The console has a transformer 250 that supplies a drive signal to the surgical tool. A linear amplifier 115 including an active resistor connects an end portion of primary winding of the transformer selectively to the ground and an open circuit state. A feedback voltage from the winding of the transformer adjusts resistance of the active resistor.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates generally to ultrasonically driven surgical tool systems. The present invention provides a controller capable of outputting drive signals over a wide range of frequencies and voltages. The present invention relates to an ultrasonic tool system equipped with a console. [Background technology]

[0002] Ultrasonic surgical instruments are surgical instruments that are useful in performing certain medical and surgical procedures. Generally, ultrasonic surgical tools include a handheld device having at least one piezoelectric driver. The tip is mechanically connected to the driver, and the tip is The distal end extends forward from a housing or shell in which the distal end is disposed. The distal end has a head. They have features, often teeth or grooves, sized to perform a particular medical or surgical task. The handpiece is part of an ultrasonic tool system. It also has a control console, which provides the AC drive signals to the driver. When a drive signal is applied to the driver, the driver expands and contracts periodically. Contraction induces a similar movement in the tip, more specifically in the head of the tip. When moving in this way, the tip is considered to be vibrating. The needle is applied to a tissue to perform a specific surgical or medical task. The apical head of the seed is applied to hard tissue. One form of hard tissue is bone. This type of When the tip head vibrates, it vibrates back and forth, causing the adjacent hard The other tip head is designed to be applied to soft tissue. When this tip head vibrates, the teeth often cut into the tissue with a cutting action. Other ultrasonic tips induce cavitation in the tissue and surrounding fluids. The tip head moves back and forth, resulting in cavitation. Specifically, these vibrations result in the body fluids located immediately adjacent to the tissues becoming Small cavities form within the cavity. These cavities are very small areas of extremely low pressure. A pressure difference occurs between the contents of the cells that make up the tissue and these cavities. These cell wall ruptures remove the cells that make up the tissue. To be removed, i.e. excised.

[0003] Ultrasonic tip heads are often relatively small. Some heads are less than 1.0 cm. The ultrasonic tool is essentially a device that cuts the tissue adjacent to where the head is placed. Due to the relatively small surface area of ​​the head, ultrasonic handpieces are able to penetrate hard tissue. It has proven to be a useful tool for precise removal of both hard and soft tissue.

[0004] Some ultrasonic tips have a through hole. At the same time that pressure is applied, suction is applied through the holes. The suction is generated by the tissue removal process. This is why some ultrasonic tools are called ultrasonic aspirators. This is why there are cases.

[0005] Ultrasonic surgical instruments, sometimes called handpieces or tools, operate efficiently. In order for the tool to function properly, a drive signal with the appropriate characteristics must be applied to the tool. If the head does not have the required characteristics, it may be subjected to vibrations of less than the optimum amplitude. When the handpiece is in this state, the handpiece is This may result in a significant reduction in endpiece capacity.

[0006] One way to ensure that an ultrasonic handpiece operates efficiently is to The goal is to apply a drive signal to the handpiece that is at the resonant frequency of the By applying a drive signal at the resonant frequency when the Compared to when a voltage of the same wave number is applied, a vibration of a relatively large amplitude is induced at the tip. do.

[0007] Yet another ultrasonic tool system generates a drive signal at the anti-resonant frequency of the handpiece. The anti-resonance frequency is the frequency at which the handpiece experiences the highest impedance. The resonant and anti-resonant frequencies of the handpiece may be It may also be desirable to apply a drive signal at a frequency between

[0008] Furthermore, the amplitude of the tip vibration is also related to the potential or voltage of the drive signal. The amplitude of the end vibration is proportional to the voltage of the drive signal. However, even if the voltage exceeds that, the result is usually There is a voltage at which the amplitude of the tip vibration no longer increases.

[0009] Within the console are components that generate the drive signals. The components can be divided into four main subassemblies: These components detect the characteristics of the drive signal delivered to the handpiece. The input / output assembly monitors the characteristics of the drive signal that is to be applied to the handpiece. The surgeon inputs commands through the input / output assembly to control the system's operating state. It serves as an interface on which information about the third asset is displayed. The assembly is the controller. The controller processes the commands entered by the user and the sensing configuration. The controller generates a control signal based on the signal from the input / output assembly. It also generates the information presented on the assembly.

[0010] The control signal generated by the controller is sent to the fourth subassembly of the console component. This places constraints on the components that make up the controller. Therefore, the control signals usually have a potential of 10 volts or less, and often 5 volts or less. For a drive signal to induce the desired contraction and expansion of the transducer, the signal Typically, it must have a potential of at least 500 volts, and often 1000 volts. Many console amplifiers amplify the control signal to produce an output signal that is so that the signal reaches a potential that can act as a drive signal applied to the handpiece. do.

[0011] Applicant's SONOPET® ultrasonic aspirator produces a variable drive signal. A console with components designed to apply voltage to an attached handpiece. There is a resonant circuit inside the console. During the manufacture of the console, this resonant circuit The inductance and capacitance of the It is set according to the impedance of the particular handpiece being used. The characteristics of the drive signal are set according to the voltage across this impedance circuit.

[0012] The control consoles provided with many ultrasonic tool systems operate in a narrow frequency range. and outputting a drive signal that promotes expansion and contraction of the desired handpiece driver over a period of time. For example, some control consoles have amplifiers capable of handling 25.2 kHz to 25 This type of control console outputs a drive signal with a frequency of .6 kHz. A driver designed to operate with a drive signal having a frequency within the frequency range. Works well with handpieces that include a 300-mW 10 ... When a handpiece with a driver that has been The responsiveness of the handpiece to the signal will not be optimal.

[0013] As a result of these constraints, widely differing drive signals may be applied in a given installation. If ultrasonic handpieces are desired, multiple control consoles may be provided. Specifically, it may be necessary to use one console to define a first set of characteristics. A drive signal is applied to the handpiece having the drive signal. and providing a drive signal to a handpiece to which the drive signal having the second set of characteristics is applied. The only difference between these consoles is the form of the drive signal that is generated. This increases the cost and administrative burden of operating a facility that uses this equipment.

[0014] Additionally, the console may be designed to generate a drive signal that is in accordance with the intended Even when generating signals that are within the frequency range that is optimal for some operating conditions, This may not generate the correct drive signal that the console was intended to generate. At one or both ends of the signal voltage range, amplifiers in the console adjust the voltage of the drive signal This is because the input signal used to establish .

[0015] Additionally, some tips, when activated, perform a motion that is a combination of two different motions. For example, some tips are designed to vibrate with a The first component is a longitudinal vibration. This is caused by the longitudinal axis of the tip. The second component is a rotational or torsional vibration. It is a reciprocating rotational motion around the longitudinal axis of the end. In general, it can vibrate in two modes simultaneously. A tip that can participate in two-mode vibration is called a tip that can participate in three or more modes. A tip designed to vibrate simultaneously at multiple modes can participate in multi-mode vibration. It is called.

[0016] Since the tip is involved in two-mode or multi-mode vibration, A drive signal that is a combination of signals that is most suitable for driving the tip is applied to the tip. Often these signals are at different frequencies. Consoles that can only generate dynamic signals often have frequencies that differ by more than 1000 Hz. However, it is not suitable for generating a drive signal that is a composite of components having frequencies that overlap. Summary of the Invention

[0017] The present invention relates to a new and useful ultrasonic tool system. The handpiece has a console to which the handpiece is attached. The console is adapted to control the driver in the handpiece. A further feature of the present invention is that the console is The advantage of the present invention is that it can provide drive signals over a wide range of potentials and in a wide range of number. The console is used to drive different handpieces that require drive signals with different characteristics. A dynamic signal can be provided.

[0018] A further feature of the system of the present invention is that it is designed to have relatively low internal energy losses. More specifically, the console of the present invention is designed with While the energy loss is relatively small, it is applied to the handpiece driver when needed. The potential of the drive signal can be rapidly ramped up. The time when the tip of the handpiece is applied to tissue to perform a procedure and the time when the tip is used The time difference between when the tip vibrates and when it does so at the interval desired by the practitioner is minimized.

[0019] The console of this system typically consists of an amplifier assembly consisting of a linear amplifier, a power supply, and a transformer. The power supply applies a DC signal to the center tap of the primary winding of the transformer. The amplifier selectively pulls both ends of the transformer primary winding to ground or to a substantially open circuit condition. By sequentially connecting the ends of the transformer primary winding to ground or to an open circuit, the winding is This induces an AC signal in the secondary winding of the transformer. This signal appearing on the line is the drive signal applied to the handpiece driver.

[0020] A linear amplifier has a transistor connected across the primary winding of a transformer. , controls application of a signal to the transistor. This causes the transistor to selectively The ends of the primary winding are connected to ground and disconnected from ground. Thus, the transistor acts as an active resistor. It functions as a vessel.

[0021] In a preferred version of the invention, the linear amplifier is implemented as a negative feedback loop. This negative feedback loop controls the application of a signal to the transistor. do.

[0022] In a preferred version of the invention, at least one of the gate or base of each transistor is This means that when a transistor needs to be turned on, , ensuring a fast response of the transistor. In this embodiment, the transistor connected to the primary winding of the transformer is a MOSFET.

[0023] In a preferred version of the invention, the voltage of the signal that the power supply applies to the center tap varies It can be done.

[0024] The processor, which is also part of the control console, measures the DC voltage level of the signal coming out of the power supply. More specifically, the processor sets the transceiver and applies the input signal to the linear amplifier. The minimum voltage across the resistor is ideally at least the headroom voltage from the power supply. Sets the DC voltage of the signal that is output. This ensures that the transistor is always saturated. In order to ensure that the voltage across the transistors is Keep the headroom voltage at a level that is not too high. This is to prevent the transistors from heating up. This is to minimize losses. Also, by maintaining the headroom voltage, the amplifier , the initially increased drive signal potential is increased without appearing as a clipped signal. can be rapidly increased.

[0025] The processor adjusts the signal output from the linear amplifier and the power supply so that the voltage of the drive signal increases. When a transistor is applied, the voltage across the primary winding can suddenly rise and take the transistor out of saturation. The processor adjusts the signal output from the power supply so that the voltage of the drive signal is reduced. When the center tap voltage is increased, the center tap voltage is increased so that the center tap voltage is increased. The drive signal does not significantly slow this voltage increase.

[0026] One specific embodiment of the present invention is an ultrasonic surgical tool system. It should be understood that the tools can be applied to other purposes. A surgical electric handpiece in which a power generating unit is an assembly other than a pair of ultrasonic drivers An AC drive signal can be applied to the

[0027] The invention is pointed out with particularity in the appended claims. The above and further features and advantages of the invention are set forth in the appended claims. As will be understood from the following detailed description taken in conjunction with the following drawings, do. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 illustrates the basic components of an ultrasonic tool system including features of the present invention. [Diagram 2] FIG. 2 is an illustration of the mechanical components of the tool or handpiece of the system. [Diagram 3] FIG. 2 is a block diagram of the electrical components of both the control console and handpiece components of the system of the present invention. [Figure 4] FIG. 1 is a block diagram of the linear amplifier and DC power supply located in the control console. [Diagram 5] FIG. 2 is an illustrative block diagram of some of the components integral with the boost converter of the control console's power supply. [Figure 6] FIG. 6 is an assembly diagram showing the configuration of the linear amplifier of the control console of the present invention according to FIGS. 6A to 6D. [Figure 6A] FIG. 2 is an illustration of a linear amplifier of the control console of the present invention. [Figure 6B] FIG. 2 is an illustration of a linear amplifier of the control console of the present invention. [Figure 6C] FIG. 2 is an illustration of a linear amplifier of the control console of the present invention. [Figure 6D] FIG. 2 is an illustration of a linear amplifier of the control console of the present invention. [Figure 7] FIG. 7 is a diagram showing the waveform appearing at the output of the operational amplifier of a linear amplifier. [Figure 8A] FIG. 8A shows the waveforms appearing at the output of the rectifier and splitter of a linear amplifier. [Figure 8B] FIG. 8B shows the waveforms appearing at the output of the rectifier and splitter of the linear amplifier. [Figure 9A] FIG. 9A is a diagram showing a waveform of a current generated by a first current source of a linear amplifier. [Figure 9B] FIG. 9B is a diagram showing a waveform of a current generated by a second current source of the linear amplifier. [Figure 10] FIG. 10 is a diagram showing the voltages appearing at each end of the primary winding of a transformer. [Figure 11] FIG. 11 is a diagram showing the voltages appearing across the primary winding of a transformer when the voltages of FIG. 10 appear at each end of the winding. [Figure 12] FIG. 12 is a diagram showing the voltage appearing across the primary winding of the transformer when the minimum voltage is at the headroom voltage. [Figure 13]FIG. 13 is a diagram illustrating the voltage appearing across the primary winding of a transformer when an increase in voltage swing causes the minimum voltage to fall below the headroom voltage. [Figure 14] FIG. 2 illustrates the types of data stored in memory within the handpiece. [Figure 15] FIG. 15 is an assembly diagram showing how FIGS. 15A-15D are assembled to represent software modules executing on a processor within the control console for adjusting the characteristics of the drive signal output from the console. [Figure 15A] FIG. 13 is a diagram representing a software module executing on a processor within the control console for adjusting characteristics of the drive signal output from the console. [Figure 15B] FIG. 13 is a diagram representing software modules executing on a processor within the control console for adjusting characteristics of the drive signal output by the console. [Figure 15C] FIG. 13 is a diagram representing software modules executing on a processor within the control console for adjusting characteristics of the drive signal output by the console. [Figure 15D] FIG. 13 is a diagram representing software modules executing on a processor within the control console for adjusting characteristics of the drive signal output by the console. [Figure 16] 1 is a flow chart of process steps performed by a base voltage limiter module executing on the console processor. [Figure 17] 4 is a flow chart of process steps performed by a power supply voltage limiter module executing on the console processor. [Figure 18] FIG. 2 is an illustration of an alternative circuit of the present invention for generating a signal across a transistor forming an active resistor of a linear amplifier. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] 1 and 2, an ultrasonic tool system 40 having the mechanism of the present invention will be generally described. The system 40 includes a handpiece 330. The handpiece 330 includes a hand The handpiece has a body or shell 342 that forms the proximal end of the handpiece. This means that the handpiece is closer to the practitioner who holds it and is farther away from the area where the handpiece is applied. "Distal" should be understood to mean away from the practitioner and closer to the site where the handpiece is applied. (This should be understood to mean that.)

[0030] One or more vibratory piezoelectric drivers 344 (four shown) are disposed within shell 342. In FIG. 2, the internal components of handpiece 330 are shown. The handpiece shell 342 is not shown. Each driver 344 is connected to a power supply 346. It is made of materials that undergo instantaneous expansion or contraction when pressure is applied. This occurs on the longitudinal axis of the driver 344. This axis is bounded by the proximal and distal faces of the driver. A pair of leads 346 (FIG. 3) extend from each driver 344. Leads 346 are attached to opposing proximal and distal faces of driver 344. Many, but not all, handpieces 330 include a disk-shaped piezoelectric driver. These drivers 348 are arranged end-to-end in the stack. The lead 346 is a component of the system 40 that carries the current for the drive signal. The voltage is applied to the driver 348 in the form of an insulating disk 350. The adjacent leads 346 connected to the insulating disk 350 are separated from each other. In Figure 2, the drivers 348 are shown spaced apart from one another. This is for ease of illustrating the components. In reality, the isolated driver 344 And the disks 350 are in contact with each other without any gaps.

[0031] The post 336 extends longitudinally through the driver 348 and the insulating disk 350. The post 336 is aligned with the driver 344 along the driver's collinear longitudinal axis. It is located inside the driver 348 and the insulating disk 350 and extends through the post 3 The through hole through which post 336 extends is not shown. The protruding ends extend outwardly from both driver 40 and the distal-most driver.

[0032] A proximal end mass is provided on the proximal face of the proximal-most driver 348. The exposed proximal end face of post 336 is fixedly attached to mass 334. If post 336 is threaded, mass 334 can be a nut. do.

[0033] A horn 356 extends forward from the distal face of the distal-most driver 344. Although not shown, an insulating disk 344 is disposed between the distal driver 344 and the horn 356. 50. The horn 356 has a base with a diameter approximately equal to the diameter of the driver 344. As it progresses forward distally from the driver 348, the diameter of the horn 356 decreases. The exposed distal end face of post 336 is secured to horn 356. If post 336 is threaded, the base of the horn may be threaded to receive post 336. A threaded, closed end hole (not shown) may be formed. The driver 344 stacks The handpiece 330 is clamped between the proximal end mass 334 and the horn 356. It is composed.

[0034] A tip 360 extends forward from the distal end of the horn 356. The coupling assembly typically includes a tip 360 and a horn 356, and thus a handpiece 33. The structure of the coupling assembly is part of the present invention. The tip 360 has an elongated stem 362. The stem 362 is part of the tip. , and is attached to the horn 356 through a coupling assembly. The mandrel 362 is The tip 360 extends forward of the shell 342. The tip 360 is attached to the distal end of the stem 362 by a head 364. Some of the tip heads 364 have a smooth surface. Some of the heads 364 are formed with teeth 366. The shape of the heads 364 is in accordance with the present invention. The distal head 364 is applied to the area on the patient where the procedure is to be performed. This is part of the handpiece 330.

[0035] Some tips 360 have teeth designed to be applied directly to hard tissue, i.e. bone. When this type of tip reciprocates, it cuts tissue in the same way that a traditional saw blade does. In this way the teeth cut the tissue.

[0036] A sleeve 370, depicted as a ring in FIG. 2, is generally disposed over the tip shaft 362. The sleeve 370 is typically located near where the mandrel is attached to the horn 356. The handpiece 330 extends from the tip of the handpiece 330 to a location approximately 0.5 cm away from the head 364. The tip 360 and sleeve 370 are both formed with an outer surface of the tip and a surrounding inner surface of the sleeve. The sleeve is configured to define a fluid flow path (conduit) extending therebetween. Sleeve 370 also includes a fitting (not shown) adjacent the proximal end of the sleeve and extending into the flow passage. The flow passage is open at the distal end of the sleeve. During use, the irrigating solution flows down the sleeve from the sleeve fitting. , exiting adjacent tip head 364. In some versions of the system, The body acts as a medium through which the mechanical vibrations of the tip head are transmitted to the tissue. This perfusion fluid absorbs the thermal energy generated by the tip head as a result of the vibration of the head. It also acts as a heat sink for the gas.

[0037] Although not shown, the post 336, horn 356 and tip 360 of the handpiece may be In most cases, conduits are formed. Both of these conduits are connected to the tip head 36 4 to the proximal end of the handpiece 330. When the suction is applied, suction is created through these conduits. The suction is applied through sleeve 370. The tip of the catheter sucks in the perfusion fluid that is expelled and leaves the area where the tip is placed. Accompanying this are tissue fragments that are generated as a result of the action of the tip 360. Also, the suction The tissue is sucked toward the tip head. This increases the transmission of mechanical vibrations from the tip head to the tissue.

[0038] The handpiece 330 of the system 40 capable of providing suction may be an aspirator or an ultrasonic aspirator. It may be called a puller.

[0039] The handpiece 330 also includes a memory 338. The memory 338 stores the The memory 338 may be an EPROM, EEPROM or RFID tag. The structure of the memory is not part of the present invention. The memory 338 also includes data identifying the handpiece driver 34. The present invention also includes data describing the characteristics of drive signals that can be applied to the handheld device 8. Piece 330 contains a memory, which contains data that can be read. Additionally, data may be stored that is written to the memory after the handpiece is manufactured. Ancillary components, not shown, are responsible for reading and storing data from and to the memory. These components are attached to the handpiece to facilitate writing. The following components are included: conductors, exposed contacts / contact pins, coils / amps, The MOSFET may consist of one or more of a MOSFET, a MOSFET transmitter, or an isolation circuit.

[0040] A control console 50 is also part of the system 40 of the present invention. The drive signal is provided via cable 326 which is connected to end piece 330. System 4 In many, but not all, versions of the .0, the cable 326 and handpiece 33 0 are assembled as a single unit. The drive signal is applied to the driver 344. At any given time, the same drive signal is applied to each driver 344. This causes the driver 344 to expand and contract simultaneously and periodically. The stack is often 1cm to 5cm long. The distance of motion across the cycle, i.e., the amplitude, can be between 1 micron and 10 microns. The horn 356 amplifies this motion. As a result, the When the horn 356 moves to the fully expanded position, the distal end of the horn 356 and, by extension, the tip 364 is usually up to 1000 microns, and more often 500 microns. Some of the tips 360 move as the tip shaft 362 expands and contracts in the longitudinal direction. The actuator is further designed to induce a rotational motion in the actuator. This rotational motion is called twisting motion. When the handpiece 330 is actuated to cause cyclic movement of the tip , head 364 is considered to be vibrating.

[0041] Components present within control console 40, generally shown in FIG. 3, include power supply 84. The power supply 84 outputs a variable voltage of 25 VDC to 250 VDC. The resulting signal is applied to the center tap of the primary winding of an isolation transformer 250 . The potential of the signal output from the power supply 84 is the POWER_SUPPLY_C applied to the power supply. ONTROL (PS_CNTRL) signal. Both ends of the transformer primary winding The section is connected to an amplifier 115. The amplifier 115 outputs an AC A signal is applied across the primary winding of the transformer. It is applied as a control signal to amplifier 115. The BASE signal adjusts the frequency and potential of the signal output from the amplifier.

[0042] The AC signal produced at the primary winding of the transformer 250 is converted to an AC signal at the secondary winding 258 of the transformer 250. This signal on the secondary winding of the transformer 250 is transmitted to the harmonics via cable 326. This is the drive signal applied to the endpiece driver 348.

[0043] The transformer 250 includes a tickler coil 256. The voltage of the signal is applied to a voltage measurement circuit 66. The circuit 66 outputs a signal representing the magnitude and phase of the potential of the drive signal applied to the driver 344. V S Given the function and location of the regenerative coil 256, this component generates a sense winding Coil 262, also located within control console 50, is a transformer The coil is located in close proximity to one of the conductors extending from the secondary winding 258 of the transformer. The signal at 262 is applied to a current measurement circuit 68. The circuit 68 measures the current i S , i.e. That is, a signal representing the magnitude and phase of the current of the drive signal supplied to the handpiece driver 344. Generate a number.

[0044] Signals representing the voltage and current of the drive signal applied to the handpiece 330 are also The control console 50 also has a memory The handpiece also has a memory reader 78. The memory reader 78 reads the data in the handpiece memory 338. The structure of the memory reader 78 is complementary to the handpiece memory 338. Therefore, the memory reader can read the data in the EPROM or EEPROM. An assembly that can read and read information from an RFID tag. The assembly may be capable of reading data from the memory 338. The stored data is read out via the conductors through which the drive signals are provided to the handpiece 32. In some versions of the invention, memory reader 78 includes an isolation circuit. The data read by the reader 78 is applied to a processor 80. do.

[0045] An on-off switch is connected to the control console 64. In FIG. The off switch is represented by a foot pedal 54. The state of the pedal 54 is 80. The on-off switch controls the on-off state of the system 30. In FIG. 1, foot pedal 54 is a user-operated control that An additional pedal may be used to control the perfusion pump. These auxiliary devices can control devices such as a water heater, a suction pump, or a light. is not part of this invention.

[0046] The control console 50 is shown as having a slide switch 56. Similar to controller 54, the state of switch 56 is monitored by processor 80. The switch 56 is set by the practitioner to control the magnitude of the vibration amplitude of the tip head 52. Foot pedal 54 and switch 56 control the system 40 to on / off and amplitude settings. It should be understood to generally represent any means of entering commands. In this configuration, a single control member can perform both functions. When the foot pedal is first pressed, the system releases a relatively small tip head. The system can be configured to undergo a vibration cycle consisting of a lever or As a result of continuing to press the foot pedal, the tip head 364 vibrates at a greater magnitude. The control console reconfigures the drive signal applied to the handpiece to undergo the cycle. do.

[0047] The control console 50 includes a display 82. is shown as being generated by processor 80. The information provided includes information identifying the handpiece and, in some cases, the tip, and the system. and information characteristic of the rate of operation of the display 82. The display 82 is a touch screen display. In these versions of the invention, the display 82 may be Entering commands into the processor 80 by pressing the image of a button that is displayed on the screen. The interface components between the display 82 and the processor 80 are shown in FIG. These interface components are responsible for the presentation of images on the display 82 and and facilitates input of commands to processor 80.

[0048] The processor 80 regulates the output of the drive signals from the control console 40. The control input from the practitioner on which 80 sets the drive signal is the state of the on-off pedal 54 and and the state of slide switch 56. Commands entered through display 82 are The drive signal settings can also be controlled. The characteristics of the drive signal can also be set in the handpiece memory. The characteristics of the drive signal are set based on the data read from the drive 338. It is used by the console as a feedback signal to further contribute to the setting of the signal. Based on these multiple inputs, the processor 80 outputs a signal that controls the drive signal. These signals correspond to the POWER_SUPPLY_CONTROL signals applied to the power supply 84. and the BASE signal applied to amplifier 115.

[0049] FIG. 4 is a block diagram of the subassemblies within the console that comprise the power supply 84 and amplifier 115. The power supply 84 includes a constant voltage power supply 86. In one version of the invention, The voltage source 86 outputs a 24 VDC signal. Transformers, rectifiers, filters and voltage regulators that convert the 1000V (1000mV) into a stable DC voltage. The processor 80 and the console such as the display 82 are not shown. A voltage within the console that generates the constant voltage signal required to operate the components within These voltage sources are also not shown in the figure. CC Voltage and -V EE Voltage Includes a voltage source that generates

[0050] The stable DC voltage output from power supply 86 is supplied by an adjustable boost regulator that is also part of power supply 84. The boost converter 88 receives the signal from the constant voltage power supply 86. The potential of the amplifier is amplified to a different potential, and the resulting signal is output as a VAMP signal. In this version, the boost converter 88 converts the potential received from the constant voltage source into a 25V In other versions of the invention, the boosted signal is The processor 88 generates a variable output signal from 25 VDC to 250 VDC. The POWER_SUPPLY_CONTROL signal output by the 80 is the boost The POWER_SUPPLY_CONTROL signal is applied to the boost converter 88. A strip converter 88 serves as a control input signal that sets the potential of the VAMP signal.

[0051] The amplifier 115 is a linear amplifier. One of the subassemblies of the amplifier 115 is a summing The summing amplifier 122 has two inputs. The first of these inputs is The first input is the BASE signal from the processor 80. The second input to the operational amplifier is the The input signal is a feedback signal, the supply of which is described below. Amplifier 122 produces the feedback conditioned BASE signal.

[0052] The feedback regulated BASE signal is applied to a rectifier and splitter 138 . Rectifier and splitter 138 splits the feedback conditioned BASE signal into a positive component and The negative component of the feedback-regulated BASE signal is split into an inverted voltage-controlled The voltage is applied to an inverting voltage controlled current source 156. The positive component of the feedback-adjusted BASE signal is driven by a non-inverting voltage controller current source. 6D, the current source 174 is connected to the The output signal from 156 can be seen applied to the gate of MOSFET 162. The output of current source 174 is applied to the gate of a MOSFET 184 .

[0053] The current sources 156 and 174 are DC biased. , when it receives no component of the feedback-conditioned BASE signal applied to that current source. The drains of MOSFETs 162 and 184 are connected to the primary winding of the transformer. 252.

[0054] The signals appearing at the drains of MOSFETs 162 and 184 are part of a linear amplifier 115. The output signal of the differential amplifier 118 is also applied to the input of the differential amplifier 118. This is the back signal and is applied to a summing amplifier 122.

[0055] The signals appearing at the drains of MOSFETs 162 and 184 are fed to headroom monitor 190. The headroom monitor 190 monitors these signals and controls the MOSFET This ensures that there is sufficient voltage across MOSFETs 62 and 184 so that these MOSFETs are always The processor 80 ensures that the headroom is saturated. Using measurements made on the VAMP signal generated by boost converter 88, Adjust the pressure.

[0056] As shown in FIG. 5, the boost converter 88 includes multiple boost circuits. The circuit includes an inductor 110. One end of the inductor 110 is connected to the constant voltage bus 91. Bus 91 is connected to the power supply 86 through which a constant voltage signal is applied to the boost converter 88. In some versions of the invention, there is a 24 VDC signal on bus 91. The other end of the inductor 110 is coupled to an n-channel FET 112. The sources of boost 2 are grounded through resistors 114 which are also part of the boost circuit. The output circuit includes a diode 111 whose anode is connected to an inductor 110 and a FET 112. The gate of each FET 112 is controlled by the DC / DC controller 90. In the illustrated version of the invention, the controller 90 is The gate signal is output to two FETs 112. In one version of the present invention, the Linear T LTC38 available from Technology Corporation, Milpitas, Calif. 62 Multi-Phase Current Mode Boost DC / DC Controller Step-Up DC / DC Controller) can function as DC / DC controller 90. Each gate signal output from the controller 90 is applied to a gate driver 92. In one version of the invention, a 3.2 V MOSFET is available from Microchip Company of Chandra, Arizona. The TC4422 9Amp High-Speed ​​MOSFET Driver (9 Amp High-Speed ​​MOSFET A FET Driver is used as the gate driver 92.

[0057] The cathodes of the multiple diodes 111 are connected to a single rail 117. A capacitor 113 is connected between this and ground.

[0058] The signal present on rail 117 is the output signal VAMP from the boost amplifier, The voltage is applied to the center tap of the primary winding 252 of the voltage regulator 250. The signal is coupled to ground through resistors 96 and 98 connected in series. The POWER_SUPPLY_CONTROL signal from The signal present at the junction of resistors 96, 97 and 98 is applied to the junction of resistors 96, 97 and 98. is applied to the feedback input of the DC / DC controller 90. In addition to the controller 90, the device may be programmed to adjust variables such as duty cycle, operating frequency and phase. The resistors and capacitors connected to the pins are not shown.

[0059] It will be appreciated that, in general, each FET 112 is gated on and off periodically. When each FET 112 is gated on, current flows through its associated inductor 110. When FET 112 is gated off, a current is built up in the magnetic field around inductor 110. The energy released causes a current to flow through the adjacent diode 111. The charge of this current is stored in capacitor 113. At the next turn-on of FET 112, inductor 11 The voltage present at the junction of diode 111 and FET 112 is grounded. As a result of this process, the potential of the signal present on rail 117 is applied to inductor 110. The potential of the signal increases above that of the

[0060] A plurality of inductors 110, diodes 111, FETs 112, and resistors 114 are arranged in a A boost circuit is provided. The boost circuits boost the voltage of the signal present on rail 117. The DC / DC converter is gated on and off at different times to smooth out the voltage. The controller 90 controls the gate of the boost circuit on and off. To ensure that the voltage present on rail 117 is at the desired potential, a feedback The gate control is adjusted based on the clock signal.

[0061] In FIG. 5, the boost converter 88 includes a single DC / DC controller 90 and two This is shown as having two boost circuits for ease of illustration and to provide redundancy. In some versions of the invention, the rail 117 To reduce ripple in the DC signal, the boost converter 88 is configured with three or more boost In some versions of the invention, the boost converter has six or more boost circuits. Many known DC / DC controllers have two boost circuits. It has been found that only the rectified converter can be gated. Many boost power supplies of the present invention will also have multiple DC / DC controllers 90. The time at which the controller gates the boost circuit attached to the controller is determined by: The connections between these multiple DC / DC controllers for regulation are not shown. In this case, the DC / DC controller gates on multiple boost circuits at different times. By providing signals from multiple converters, This further smooths the voltage present at rail 117.

[0062] 6A-6D taken together show the components of amplifier 115. The amplifier 122 as shown in FIG. 6C is an operational amplifier. The E signal is applied through resistor 120 to the inverting input of amplifier 122. The SE signal is used by amplifier 115 to adjust the voltage developed across transformer primary winding 252. The inverting input of amplifier 122 can be regarded as an external control signal received for the purpose of A voltage feedback signal from amplifier 240 is also applied. This signal from amplifier 240 is , is applied through resistor 121 to the inverting input of amplifier 122. A resistor 124 is connected between the output of amplifier 122 and the inverting input of the amplifier. Also connected to the summing amplifier 120 is a resistor 126 and a capacitor 128 connected in series. The non-inverting input of 22 is grounded.

[0063] Summing amplifier 122 is configured as an inverting amplifier. In many versions of the invention, this The gain of the amplifier is 4 to 10. The amplifier is made up of a resistor 126 and a capacitor 128 connected in series. The feedback circuit reduces the amplifier's utilization at high frequencies, typically above 1 MHz. This limits the local gain of the amplifier 122 by reducing the gain of the amplifier circuit. The signal generated by the summing amplifier 122 is fed back to This is called the adjusted BASE signal.

[0064] The feedback conditioned BASE signal from summing amplifier 122 is fed to capacitor 132 and and resistor 134 to the inverting input of operational amplifier 140. is part of the rectifier and splitter 138. The non-inverting input of the amplifier 140 is grounded. The output signal from amplifier 140 is fed to a Schottky diode, which is a series connection of two diodes. The resistor 144 is applied to the junction of the diodes 148 and 150. A resistor 146 is connected between the inverting input and the anode of a diode 148. 40 and the cathode of diode 150. The signal present at the connection of diode 148 is the negative of the feedback regulated BASE signal. The signal present at the junction of resistor 146 and diode 150 is the feedback signal. The positive component of the clock-adjusted BASE signal.

[0065] The rectifier and splitter 138 is configured so that the gain from the amplifier 140 is fixed. Usually the gain is less than 5. In most cases the gain is 1.

[0066] The negative component of the feedback regulated BASE signal is fed through resistor 154 to amplifier 1 The output of amplifier 158 is applied to the inverting input of amplifier 158. Amplifier 158 is part of an inverting voltage controlled current source 156. The non-inverting input of amplifier 158 is grounded. A capacitor is connected between the output and the inverting input of amplifier 158. The output signal from the amplifier 158 is connected to a resistor 161. The source of the MOSFET 162 is connected to a resistor A resistor 166 couples the inverting input of the amplifier 158 to ground through a MOSFET The resistor 165 is connected to the junction between T162 and resistor 168. The junction of amplifier 158 and resistor 166 is connected to -V EE Connect to a voltage source.

[0067] The positive component of the feedback conditioned BASE signal is applied to the non-inverting input of amplifier 176. The amplifier 176 is part of the non-inverting voltage controlled current source 174. The output signal from this amplifier is applied to the gate of a MOSFET 184 through a resistor 183. The signal present at the output of transformer 176 is applied through capacitor 178 to the inverting input of the amplifier. The inverting input of amplifier 176 is connected through resistor 179 to -V EE Connected to a voltage source The junction of the amplifier 176, the capacitor 178 and the resistor 179 is connected through a resistor 180. The resistor 182 is connected to the source of the MOSFET 184. The connection of SFET 184 is grounded.

[0068] Amplifiers 158 and 176 have the same fixed gain. Typically, this gain is less than 5. In most cases, the payoff is 1.

[0069] The signal present at the drain of MOSFET 162 is coupled through resistor 237 to a differential amplifier The signal present at the drain of MOSFET 184 is applied to the inverting input of resistor 240. The output of the differential amplifier 240 is applied through resistor 238 to the non-inverting input of the differential amplifier 240. A capacitor that may be in series between 38 and the associated input to amplifier 240 is (Not shown) The non-inverting input of differential amplifier 240 is connected to ground through resistor 239. The feedback to the amplifier 240 is provided by a resistor connected between the output and the inverting input of the amplifier. The signal present at the output of amplifier 240 passes through resistor 121. This is the signal that is applied to the summing amplifier 122.

[0070] An inductor 187 is connected between the drains of the MOSFETs 162 and 184. The drains of SFETs 162 and 184 are connected to opposite ends of a primary winding 252 of a transformer 250. will be done.

[0071] Inductor 187 is ideally connected in parallel across the driver. In this case, a circuit having a resonant frequency approximately equal to the resonant frequency of the handpiece is formed. The common inductance of the handpiece 330 is selected to be It will be appreciated that the oscillation frequency will change. The inductance of inductor 187 is fixed. Therefore, the inductance of the inductor is such that the inductor is connected in parallel to the driver 344. If the resonant frequency of this circuit is 50 times that of the resonant frequency of the handpiece 330, %, and more ideally within 25%. The resonant frequency of the handpiece is the frequency at which a drive signal is applied at a given voltage or current. When a voltage or current is applied to a frequency that is off resonance, the amplitude is larger than when the same voltage or current is applied at the frequency off resonance. It should be understood that this is the frequency of the drive signal such that a large vibration is induced in the tip.

[0072] Although not shown, in some versions of the invention, each of MOSFETs 162 and 18 The connection of 4 is made through a current sensing transformer. This current sensing transformer has two Each MOSFET 162 and 184 has a first winding on one side and a second winding on the other side. A MOSFET 162 is connected to one end of a separate primary winding of a current sensing transformer. The other end of the primary winding of the current sense transformer is connected to a first end of the transformer primary winding 252. The other end of the primary winding of the current sense transformer to which the MOSFET 184 is connected is connected to the primary winding of the transformer. 252. Thus, across the secondary winding of this current sensing transformer, The resulting signal represents the current delivered by the amplifier. The digitized representation is applied to a processor 80 which converts this signal into It monitors and determines if the amplifier is drawing too much power. The console If the processor 80 determines that such a condition exists, the processor reduces the current from the amplifier. The processor 80 performs this monitoring and Thus, the process of regulating the operation of the console is not part of the present invention.

[0073] Next, the theory of operation of the linear amplifier 115 will be explained with reference to FIGS. 7, 8A and 8B. The solution is obtained. FIG. 7 shows the feedback adjusted BAS output from summing amplifier 122. 1 is a waveform of the E signal. The rectifier and splitter 138 is a feedback regulated BASE The signal is split into positive and negative components. FIG. 8B shows the positive component of the feedback regulated BASE signal. 4 shows the negative component of the feedback regulated BASE signal present at the anode of the

[0074] The positive component of the feedback conditioned BASE signal is fed to a non-inverting voltage controlled current source 174. The half sine wave portion of the waveform seen in FIG. When the input signal is greater than 0 volts, the output signal from the current source follows the input signal. By going back to FIG. 8A, the time when the input signal to current source 174 is near zero is It will be appreciated that there is a -V EE A signal is applied Recall that amplifier 176 is thus -V EE As a result of the signal being applied, Even if the input signal is 0 volts, amplifier 176 produces a constant low voltage output signal. At A, this is represented by the straight line sections of the waveform between adjacent half-sine wave sections. These straight line portions of are above 0 volts.

[0075] The negative component of the feedback regulated BASE signal is applied to amplifier 158. The half-sine portion of the waveform seen at B is this of the feedback conditioned BASE signal. These parts are inverted by amplifier 158 and output. 58 also -V EE It will be understood that a signal is applied. This is the feedback regulated This means that when the negative component of the BASE signal is zero, the amplifier outputs a low level signal. In FIG. 9B, this is because is represented by the straight line portion of the waveform.

[0076] Therefore, the signals applied to the gates of MOSFETs 162 and 184 are 10 shows a MOSFET with both ends of the primary winding 252 of the transformer. 1 illustrates the effect of turning on and off MOSFETs 162 and 184 on the edge. The waveforms in this figure are generated when a power supply 84 applies a 100 VDC signal to the center tap of the winding. To facilitate understanding of the operation of amplifier 115, the waveform of FIG. The shape ensures that there is sufficient headroom voltage across MOSFETs 162 and 184. The need for

[0077] The solid waveform 186 in FIG. 10 is generated at the end of the winding 252 to which the MOSFET 162 is connected. This represents the voltage at the top end of winding 252 of transformer 250 in FIG. 6B. 188 represents the voltage developed at the end of the winding 252 to which the MOSFET 184 is connected. is the lower end of the winding of the transformer 250. In the first time frame, the MOSFET As a result of turning on MOSFET 184, the primary The voltage developed at the associated end of the winding is grounded and therefore pulled low. This is represented by the dashed waveform that drops from 100 volts to near 0 volts. At the same time, in this time frame, the electric field in MOSFET 16 2 is effectively off. The steepness of the electric field at the end of winding 252 to which MOSFET 184 is connected The drop induces an increase in the electric field at the other end of the winding. This end of the winding 252 effectively becomes an open circuit. Due to the fact that the winding is a stator, the voltage at this end of the winding increases. The voltage drop at the opposite end is essentially equal to the voltage drop at the opposite end. Therefore, the first positive transition of waveform 186 The voltage at this end of the winding rises from 100V to 200V, as represented by As a result of these changes in the voltage level at the opposite ends of the primary winding , the voltage developed at the top of the winding 252 is +200 volts higher than the voltage at the bottom of the winding. This is shown in Figure 11 by the initial rise of waveform 189 from 0 volts to 200 volts. It is expressed as follows.

[0078] When MOSFET 184 turns off, the voltage on the bottom side of winding 252 rises to 100 volts. The voltage on the upper side of winding 252 drops back to the center tap voltage. Returning to the tap voltage, the voltage across winding 252 drops to essentially zero. This is represented in FIG. 11 by the initial drop of waveform 189 from 200 volts to 0 volts. It has been done.

[0079] In the next time frame, MOSFET 162 turns on while MOSFET 184 remains off. The turn-off of MOSFET 162 causes the associated end of the winding The voltage on the top side of winding 252 drops from 100 volts to near ground. This is shown in FIG. 10 at the portion of waveform 186 that drops from 100 volts to approximately 0 volts. At this point, MOSFET 184 is off, thereby The bottom of the wire 252 is effectively an open circuit. The electric field near the top of the winding 252 drops sharply, resulting in The electric field near the bottom of the winding increases. This results in an increase in the potential at the bottom of the winding. This is called The primary winding is represented by the portion of waveform 188 that rises from 00 volts to 200 volts. As a result of the voltage shift across wire 252, the top of the winding will see a voltage shift higher than the bottom of the winding. This generates a voltage that is negative with respect to the voltage in the range of 0 volts to -200 volts in FIG. This is represented by the drop of waveform 189 to the zero point.

[0080] After the MOSFET 162 is turned on, the MOSFET 162 is turned off. MOSFET 184 remains off. This results in a voltage at the top of winding 252 At the same time, the voltage at the bottom of winding 252 drops back down to 100 volts. At the point when both MOSFETs 162 and 184 are effectively off, There is no effective voltage drop across the winding. This is shown in Figure 11 at -200V. This is represented by the rise of waveform 189 from its default state back to 0 volts. The turn-on and turn-off of ET162 and 184 causes both windings of the transformer primary winding 252 to An AC voltage is generated at the end.

[0081] These frames are repeated. In some versions of the invention, the primary winding 252 The turns ratio of the secondary winding 258 to the The range is 2 to 5.

[0082] In practice, the MO is turned on only when it is necessary to develop maximum voltage across the transformer primary winding 252. SFETs 162 and 184 are not turned on or off completely. It will be understood that these MOSFETs 162 and 184 are active resistors. When the resistance of the MOSFET is changed by the current sources 156 and 174, , the primary winding has a peak-to-peak voltage of less than twice the DC voltage present at the center tap. A voltage is generated.

[0083] As previously mentioned, in addition to adjusting the characteristics of the BASE signal, processor 80 It also adjusts the voltage of the VAMP signal applied to the center tap of transformer winding 252. MOSFETs 162 and 18 remain in the ON state regardless of the voltage present at the ends of transformer winding 252. Ensure that there is sufficient, but not excessive, headroom voltage present at the drain of 4 The reason for this monitoring can be understood by first referring to FIG. This diagram represents the voltage present at one end of the transformer winding 252, although not necessarily the top end. More specifically, FIG. 12 shows a 40 volt center tap voltage and a 30 volt center tap voltage. This occurs when MOSFETs 162 and 184 operate in a peak-to-peak oscillating manner. This represents the minimum voltage across the MOSFET 184 when the console 50 is in this state. The drain-source voltage is 10 volts. Assume that the minimum headroom voltage for the operating condition of the MOSF is 10 volts. When 10 volts is applied to the ET162 and 184, the MOSFETs are saturated. This means that there is enough voltage across the MOSFET to ensure that it remains in the on-state. This is the result of any change in the voltage applied to the gates of each of the MOSFETs 162 and 184. to ensure that the desired proportional change in current flows through the MOSFET. do.

[0084] In Figure 13, the voltage at the center tap remains at 30 volts, but the drive signal The need to increase the voltage means that the voltage across the primary winding of the transformer is 50 volts peak to This shows the state when MOSFETs 162 and 184 are operated to oscillate at the peak. If the voltage level at the center tap remains at 30 volts, the minimum drain The source voltage drops to 5 volts. The voltage across MOSFET 184 drops to this level. When the MOSFET 184 drops below 1V, the MOSFET may no longer be saturated. As we move away from saturation, the voltage of the signal applied to the gate changes, resulting in a There may be cases where the desired proportional change in current through the SFET does not occur. As a result, the potential present at the associated end of the transformer primary winding 252 is They are not at the potential required for a drive signal of the appropriate potential to appear across them.

[0085] Furthermore, like any amplifier, the linear amplifier 115 of the present invention generates an output signal, here a drive The output of the drive signal changes proportionally to the change in the potential of the input drive signal. This occurs when the change in drive signal voltage is based on a change in the load to which the drive signal is applied. This is especially true when the presence of this headroom voltage at the transformer center tap causes the load This allows the amplifier output to change quickly even if

[0086] The console 50 ensures that the MOSFET 162 remains in operation even during the largest winding voltage swings. and a sufficiently high voltage so that the voltage at the drain of 184 is always higher than the saturation level. Pressure can be configured to be applied to the center tap at any time. The disadvantage of operating the console in this manner is that the MOSFETs 162 and 184 By constantly applying a voltage, a significant amount of the electrical energy applied to the MOSFET The amount of heat that is converted into thermal energy, i.e., unwanted heat, is called excessive heat. To prevent unnecessary heat loss, the processor 80 determines whether the VAMP signal output from the converter is: While providing sufficient headroom for MOSFETs 162 and 184, the resulting To ensure that the power dissipation in the boost converter is not at a level that would result in unnecessary heat loss in T, Constantly adjust the 88.

[0087] In order for the processor 80 to adjust the VAMP and BASE signals, The processor receives as input the HEADROOM (HDRM) signal, which represents the headroom voltage. The HEADROOM signal will now be described with reference to Figures 6A and 6B. The headroom monitor 190 receives the signal from two diodes. The anodes of both diodes 196 and 198 are connected to a capacitor. V through Ta 192 CC The cathode of diode 196 is connected to a voltage source. The cathode of diode 198 is connected to the drain of MOSFET 184. A resistor 202 is connected across the capacitor 192. The signal appearing at the junction of the resistor 192, the diodes 196 and 198, and the resistor 202 is The input of the amplifier 212 is applied through a resistor 204 to the non-inverting input of the amplifier 212. A capacitor 206 is connected between the input and ground. The output signal of the amplifier 212 is Connected to the inverting input.

[0088] The output signal of amplifier 212 is applied through resistor 214 to the non-inverting input of amplifier 230. A resistor 216 and a capacitor 218 are connected between the non-inverting input of amplifier 230 and ground. are connected in parallel.

[0089] The headroom monitor 190 also includes two resistors 224 and 226 connected in series. The free terminal of resistor 224 is V CC The free end of resistor 226 is connected to the rail. The resistor 224 and the capacitor 228 are connected across the resistor 226. The signal appearing at the junction of capacitor 226 and capacitor 228 is amplified through resistor 229. The inverting input of the resistor 230 is connected in parallel to the capacitor 232 and the resistor 234. is between the output of amplifier 230 and its inverting input. The output signal of amplifier 230 is The end of resistor 234 away from amplifier 228 is connected to a capacitor. The signal generated at the junction of resistor 234 and capacitor 236 is The signal is the V across the MOSFETs 162 and 184. DS HEADROOM signal representing voltage be.

[0090] The Headroom Monitor 190 is a DS It does not monitor voltage directly. Instead, , the headroom monitor 190 monitors the voltages of the MOSFETs 162 and 184 with respect to ground. The voltage at the drain of the MOSFET 164 is monitored. and the voltage across resistor 168. In the case of MOSFET 182, and the voltage across resistor 182. The voltage of V CC When the potential drops below the signal potential, current flows through diode 196 or 198. When this state ends, a voltage is applied through resistor 204 to the non-inverting input of amplifier 212. The potential of the signal drops. The output signal of amplifier 212 also drops. A similar drop occurs in the output signal of the 28, which in turn causes a voltage drop in the HEADROOM signal. do.

[0091] By selectively setting the resistance of resistors 224 and 226, MOSFET 162 and and 184 to selectively adjust the potential of the HEADROOM signal relative to the actual headroom voltage applied to the In one version of the invention, resistors 224 and 226 can be set to: When the HEADROOM signal potential is 0 volts, The voltage is selected to be a specific voltage in the range of 8.5 volts to 10.5 volts.

[0092] The VAMP signal from the boost converter 88 is fed to the sensor of the primary winding 252 of the transformer 250. The VAMP signal is applied to the transformer tap 250. Also shown is a single capacitor 248 connected to the ac component of the signal. represents the filtering of the VAMP signal to minimize

[0093] The VAMP signal is applied from the boost converter 88 to the transformer center tap 252. Not shown is a relay that may be in series with the conductors passing through the switch. The diagnostic checks that are part of the system preparation process confirmed that no faults were detected. It is switched on by the processor after it indicates that The process by which this occurs is not part of this invention. If a relay is present, the VAMP signal passes through it. A reverse-biased diode is also connected between the buses that are applied to the center tap of the transformer. This diode protects the console if the relay is opened.

[0094] In FIG. 6B, both ends of the transformer secondary winding 258 are connected to the handpiece driver 344. The regenerative coil 256 is a source of the applied drive signal. One end of the regenerative coil 256 is grounded. The HPVMON signal that appears at the other end of 256 is the drive signal V S This is a signal that represents the voltage of HP The VMON signal is applied to a voltage monitor 66. At the console 40, the secondary winding of the transformer One of the conductors extending from line 258 is shown in close proximity to coil 262. The signals applied to coil 262 in FIG. The signal is the drive signal current i S The HPISNS+ and HPISNS- signals are is the signal applied to the current monitor 68. Based on the signal, the current monitor 68 measures the current i S Generate a representation of

[0095] To facilitate operation of the system 40, the handpiece internal memory 338 is The data is loaded when the end piece is assembled. The data includes data identifying the handpiece 330. Useful for verifying that the console 50 can apply a drive signal to the handpiece. The data in field 372 is used to determine the hand-picker status presented on the console display 82. The field 374 may also indicate the type of information about the driver 348. Stack capacitance C OThe capacitance of the driver is This can be determined analytically during the process of assembling the handpiece 330. In this case, the sum of the capacitances of the drivers 348 is 500 pF to 5000 pF. The maximum current that can be applied to the

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[0096] Also stored in handpiece memory 338 is the frequency of the power supply applied to handpiece 330. The data stored in field 382 indicates the minimum and maximum frequencies of the drive signal. The minimum frequency that can be achieved is usually the minimum frequency of the drive signal that can be provided by the control console. The maximum frequency of the drive signal stored in field 384 is typically 5 kHz to 40 kHz. z, which is greater than the minimum frequency.

[0097] Field 386 is a field for filtering the signal output from processor 80. Field 388 contains a coefficient that indicates the magnitude of the drive signal potential applied to the handpiece. Includes data regarding any step limits associated with the increment. As well as the data in field 374, fields 372, 376, 378, 380, and 38 The data in 2, 384, 386 and 388 are part of the process of assembling the handpiece. It should be understood that the time stamp is stored in the handpiece memory 58 as

[0098] The handpiece memory 338 also has a field 390 as a usage history field. The control console 50 is configured to provide a log of the operation of the handpiece as it is being used. The data is written to field 388 as follows:

[0099] 15A to 15D, the console 50 can be connected to the handpiece 330. A diagram of the process executed on processor 80 to adjust the output drive signal is provided. Briefly, the purpose is to allow the console 50 to, and in turn, the handpiece driver 34 4 outputs a drive signal of a frequency and voltage that periodically expands and contracts as desired. It should be understood that the BASE signal and the POWER_SUPPLY_CON The TROL signal is a control signal that other components within the console 50 use to generate target drive signals. The processor 80 outputs the BASE The amplifier 115 generates a BASE signal and a signal generated by the amplifier. This feedback regulated BASE signal is generated according to the The BASE signal is the signal that amplifier 115 subsequently generates across the transformer primary winding 252. The frequency and potential of the transformer are such that a signal is generated across the primary winding 252 of the transformer. The particular signal generated by amplifier 115 is a signal that induces a target drive signal across secondary winding 258. This is a signal that

[0100] The processor 80 outputs the POWER_SUPPLY_CONTROL signal. , the potential VAMP applied by the power supply 84 to the center tap of the transformer primary winding 252 is sufficiently MOSFETs 162 and 184 have a headroom at the drains that is not too large. This ensures that the voltage is at a level that

[0101] To generate the BASE and POWER_SUPPLY_CONTROL signals, The processor 80 continuously executes three control loops. The first control loop controls the BASE signal. The second control loop sets the voltage of the BASE signal. The outputs of these two control loops are combined to generate the BASE signal. The second control generates the POWER_SUPPLY_CONTROL signal. The output of the control loop for setting the voltage of the BASE signal is the third control This is the input to the control loop.

[0102] Amplifiers 118 and 122, rectifier and splitter 138, and current sources 156 and 17 The gain of the transformer is fixed. Therefore, the voltage of the signal applied across the transformer primary winding 252 is The voltage of the BASE signal is proportional to the voltage of the BASE signal. The frequency of the BASE signal is 2. Therefore, the module running on the processor 80 In the following description of the module, the voltage and frequency of the BASE signal is These characteristics of the signal generated at the BASE signal are used as input variables. The frequency of the BASE signal is , is the frequency of the drive signal developed across the secondary winding 258 of the transformer. This is what the module running on the processor takes as input variable the frequency of the drive signal. This is why the frequency of the BASE signal can be used.

[0103] One of the modules of the first control loop is the frequency tracking calculation unit 292. The frequency tracking calculator 292 calculates the frequency currently applied to the handpiece driver 348. In one version of the invention, a frequency tracking meter is used to determine the characteristics of the drive signal. The calculation unit 292 is M i for O , i.e., flowing through the handpiece driver 344 Determine the ratio of the currents in the variable i M is applied to the mechanical components of the handpiece 330. The mechanical components of the handpiece respond to the application of a drive signal. These components are the proximal mass 334 and The post 336, the driver 344, the horn 356 including the connection assembly, and the tip 36 0. The driver 344 vibrates and is therefore one of the vibrating mechanical assemblies of the present invention. The sleeve 370 is usually included in these components. This is because the sleeve 370 vibrates but is not considered one of the components of the More specifically, the sleeve 370 is not part of the vibration system. The load on the system can be considered as a component.

[0104] The current i flowing through the driver 344 O is the capacitance of the driver, C O And dry The function is the voltage applied to the inverter and the angular frequency ω of the drive signal. More specifically, It is.

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[0105] current i S and i O , equivalent current component i M , and voltage V S are magnitude and phase components, respectively. It should be understood that the vector has the components:

[0106] To this end, the frequency tracking calculation unit 292 receives as input the V as measured at S and i based on the potential across the coil 262. S A third input to the calculation unit 292 is the handpiece memory 3 Capacitance C in field 374 of 38 O The fourth input to the calculation unit 292 is , is the current frequency of the drive signal. Based on these variables, the frequency tracking calculation section 292 is the equivalent component of the current flowing through the mechanical components of the handpiece according to the following formula: Find the ratio of the current flowing through the driver to the

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[0107] The ratio output from the calculation unit 292 is input to the base frequency controller 294. The base frequency controller 294 compares the ratio of equation (3) to a fixed value, which may be, but is not required to be, F. In practice, F can be from -100 to 100. This range is merely an example. It should be understood that the present invention is not limited to this. There are several configurations of the present invention, where F is between -1.0 and 1. 0. The system applies a drive signal that matches the mechanical resonance of the handpiece. When intended, F is typically 0. The value of F typically varies over a single use of the system 40. It is constant.

[0108] Therefore, the controller 294 performs the following evaluation:

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[0109] If the evaluation of equation (4) fails, the controller 294 This new frequency will result in The frequency at which the evaluation should pass. The new frequency is the current frequency of the drive signal. The current frequency of the drive signal is based in part on the previous cycle of the frequency calculation process. This is understood to be the frequency of the drive signal previously calculated by the controller 294 at This is why, in FIG. 15B, the previously calculated drive frequency is This is why it is shown to be a feedback to the controller 294. The calculated driving frequency is fed back to the frequency tracking calculation unit 292. The calculation unit 292 converts this previously calculated value of the BASE signal frequency into the input We use the force variable ω as the angular frequency of the drive signal.

[0110] A detailed analysis of the basis for equations (1), (2), (3), and (4) is provided in International Publication No. 2015. No. 2003 / 021216, incorporated herein by reference in its entirety. and is hereby expressly incorporated by reference in its entirety as a part of this specification.

[0111] The new frequency for the drive signal is proportional, integral and differential. Although not shown in FIG. 15B, the output is generated using a proportional-integral-derivative (PID) control loop. The coefficients for the PID loop are based on the coefficients from field 388 in the handpiece memory. A new frequency for the drive signal generated by the base frequency controller 294 can be used. The new frequency is applied to the base signal generating section 310. The degree is based on the data in fields 382 and 386 in handpiece memory 338 .

[0112] The second control loop includes a current equivalent component calculation unit 296. The current equivalent component calculation unit 296 Then, the equivalent current components of the mechanical components of the handpiece 330 are calculated according to the following equation (2): To distinguish it from the target current equivalent component described below, The calculated current equivalent components are the variables

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[0113] A second input to the base voltage controller 306 is a value representing a target machine current equivalent component

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[0114] The base voltage controller 306 is a modulator that generates the next value of the voltage for the BASE signal. The base voltage controller 306 first calculates the target current equivalent component

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[0115] In theory, the base voltage controller 306 can be implemented using a conventional control loop, such as a PID control loop. Based on the loop, a signal should be generated that indicates the newly adjusted potential for the BASE signal. do.

[0116] The rate of change of the BASE signal also allows the linear amplifier 115 to quickly ramp up the drive signal. the ability of the handpiece driver 344 to respond to rapid changes in drive signal voltage, etc. It should be understood that the voltage controller 306 may be further configured to It will be appreciated that the change in voltage level of the BASE signal is limited based on these variables. The handpiece specific voltage step limit variables are initially configured for use by the system 40. When the handpiece is started, the data read from field 388 of handpiece memory 338 is The console specific voltage step limit variables are programmed during assembly of the console 50. The data is loaded into processor 80.

[0117] In practice, other factors affect the voltage level of the drive signal applied to the handpiece driver 344. These factors include the MOSFET 162 and and 184, the maximum current that can be drawn from the transformer 250, and the and the maximum voltage of the drive signal that should be applied to the driver 344. , i.e., another control module running on the processor 80 controls the voltage controller 3 A command that limits the increase in the commanded voltage level for the BASE signal output from 06. The method selectively generates

[0118] The voltage limiter 304 limits the voltage magnitude of the BASE signal, and A voltage limiter 304 selectively limits the rate of change of the voltage of the BASE signal. One variable that can determine whether the voltage on the E signal needs to be limited is the As a result of the number of voltages, signals that exceed the maximum voltage designed for may appear on the secondary winding 258 of the transformer. In most cases, this value is fixed. In some versions of the invention, this The voltage should be at least 1000 volts peak, and more preferably at least 1250 volts. In yet another version of the invention, this voltage can be varied. The main reason this voltage can vary is that the characteristics of the handpiece 330 Under some operating conditions, the handpiece may draw excessive current from the console 50. This is because it is possible.

[0119] Therefore, in some versions of the invention, processor 80 performs full-scale voltage calculations. The input to the calculation unit 298 is the handpiece driver capacitance C O and the frequency of the drive signal. Again, the frequency of the BASE signal is It should be understood that these values ​​are used as a proxy for the total handpiece When the drive signal applied to 330 reaches a certain potential, the impedance of the driver This causes the driver to draw more current than the console 50 will provide. In general, the impedance of the driver is When the impedance is relatively low and the drive signal is at a relatively high frequency, the handpiece Conditions may arise where excessive current may be drawn by driver 344.

[0120] The calculation unit 298 uses the previously calculated frequency of the BASE signal as an input variable. The second module is the driver capacitance C O Again, the capacitance of the handpiece driver, C O is the initial setting of the system. It should be understood that the calculation unit 2 is loaded into the processor 80 at the time of initialization. 98 indicates that the handpiece driver 344 is It can be determined that the system is entering a state where excessive current is being drawn from the system. If the calculation unit 298 determines that the system 30 is in this state, the calculation unit calculates the secondary winding of the transformer. 258, i.e. the maximum voltage that should be output from the console 50. A signal to the voltage limiter 304 indicating that the voltage is at a level below the default maximum voltage. In some versions of the invention, the calculation unit 298 actually generates the transformer Determine the maximum voltage that should be allowed to develop across the primary winding 252.

[0121] The voltage limiter 304 also limits the previously calculated voltage used to generate the BASE signal. The data indicating the voltage level of the BASE signal obtained in the calculation cycle is This voltage is received from the input controller 306. This voltage determines the present input voltage appearing across the primary winding 252. The ratio of the voltage across the secondary winding 258 to the voltage across the primary winding is used as an input variable for If we assume that is constant, the previously calculated voltage of the BASE signal also appears across the secondary winding 258. It is used as a variable that inferentially indicates the voltage

[0122] Another variable applied to the voltage limiter 304 can be applied to the handpiece 330. This voltage is the maximum voltage that can be

number

[0123] The voltage limiter 304 also receives as input variables the measured The headroom voltage, or HDRM signal, is then input to limiter 304. The circuitry providing the digital representation is not shown. The variable to be considered is the target headroom voltage. This is the limit below which the headroom voltage will drop. The target headroom voltage is a voltage level that should not be exceeded. This is obtained from another module, namely the target headroom calculation unit 312 .

[0124] Based on these variables and the time it takes for the limiter 304 to perform a series of evaluations, 16. In the first step, step 402, The limiter 304 limits the voltage on the secondary winding 258 of the transformer to a voltage

number

[0125] The evaluation of step 402 determines whether the voltage across the transformer secondary winding 258 is greater than the handpiece driver voltage. This indicates that the maximum voltage of the drive signal that can be applied to the driver 344 is being approached. If this is the result of the evaluation, then in step 404 the voltage limiter 304 The voltage calculated for the BASE signal should be controlled so that it does not exceed a given amount. 4. Another result of the evaluation of step 402 is asserted to the voltage controller 306. This means that the voltage applied to the driver 344 is already at its maximum voltage. If the result of the evaluation in step 402 is 4. The controller can increase the voltage of the BASE signal above the current level The power supply 304 generates a command to the voltage controller 306 indicating that the power supply 304 is not in a standby state.

[0126] In step 406, the voltage limiter 304 detects the voltage across the transformer primary winding 252. Is the voltage that is allowed to be applied to this winding approaching the maximum voltage of the signal that is allowed to appear on this winding? The winding maximum voltage level is evaluated to see if it is equal to or greater than the default maximum voltage. , or the maximum voltage level generated by the full-scale voltage calculation unit 298, whichever is lower. It should be understood that.

[0127] In step 406, it may be determined that the drive signal is near the maximum voltage of the transformer. If this is the result of the evaluation, then in step 408, the voltage limiter 304 The voltage controller is instructed to step up the voltage of the BASE signal. Step 4 Another result of the evaluation of 06 is that the voltage limiter 304 detects that the voltage on the secondary winding 258 of the transformer is already If this is the result of the analysis in step 406, If so, in step 408, the voltage limiter 304 notifies the voltage controller 306 and the controller issues a command to increase the voltage on the BASE signal above its current level. Print the command that will prevent output.

[0128] In step 410, the voltage limiter 304 detects whether the headroom voltage is greater than the MOSFET 1 Check whether the amplifier is in a state that is sufficient to ensure saturation of 62 and 184. In step 410, the measured headroom voltage, i.e., the HDRM signal, is evaluated. In some versions of the invention, the voltage based on The target headroom voltage is between 2 volts and 20 volts. In most cases, the minimum target headroom voltage is The headroom voltage is between 4 volts and 15 volts. The measured headroom voltage is equal to the target headroom voltage. If the voltage is less than the threshold voltage, the voltage limiter 304 executes step 412. In step 412, the voltage limiter 304 is turned on to limit the increase in the level of the BASE signal. The voltage controller 306 generates an instruction to limit the magnitude of the Specifically, the voltage controller 306 can only supply BA to the maximum extent that it is configured to supply. It is indicated that the voltage level of the SE signal cannot be increased.

[0129] In FIG. 16, step 406 is shown to be performed after step 404. Step 410 is shown to be performed after step 408. This may be necessary. In response, the voltage limiter 304 issues a number of commands to limit the level of the voltage increase, based on the three evaluations. Voltage control may be used if any combination of values ​​indicates that such a limit is necessary. This is to indicate that the data can be transmitted to the data recorder 306 in step 402, 406, or 410. If one of them is executed, the voltage controller 306 acts on the received command. and limiting the voltage level of the drive signal included in the command generated by the controller. .

[0130] The evaluation of step 402 determines whether the drive signal to be applied is This often indicates that the maximum voltage to be applied is exceeded. It is determined that the voltage across the console's transformer 250 is less than the maximum allowable voltage. Similarly, in step 410, the measured headroom voltage is In many cases, it is determined that the headroom voltage is exceeded. If the evaluation results of the step 402, 406 and 410 are as described above, the voltage limiter 3 04 results in the voltage level of the BASE signal that was initially calculated by the controller 306. The controller 306 does not assert a command to limit the The voltage level of the BASE signal is the first PID calculation performed by the controller. The step generates an instruction indicating not to attenuate the level from the level calculated by the step.

[0131] In FIG. 15A, FIG. 15B, and FIG. 15C, the command from the voltage controller 306 is As mentioned above, the frequency controller 310 is shown to be applied to the base signal generator 310. The command from 294 is also applied to the base signal generator 310. Based on the received signal, the base signal generating section generates an appropriate BASE signal. This is applied to amplifier 115 to induce the desired drive signal in secondary winding 258. This is the BASE signal that is added.

[0132] As mentioned above, the control console 50 of the present invention is The voltage applied to the center tap is constantly adjusted. A single resistor determines the level of this adjustment. The input variables are the target headroom that will be present at the drains of MOSFETs 162 and 184. This target headroom voltage is also called the minimum headroom voltage. It can be a constant voltage. Although not required, this voltage can be 10 volts. This headroom voltage can be considered the default headroom voltage. Due to the characteristics of the handpiece driver 344 and the characteristics of the drive signal applied to the driver, This voltage is generated to ensure that MOSFETs 162 and 184 are saturated. There is a point in time when the voltage required for the system 40 of the present invention is significantly higher than the The minimum required to ensure that the MOSFET is saturated when in operation. The headroom voltage can be 5 volts or less.

[0133] The target headroom calculation unit 312 calculates the target headroom based on the operating conditions of the system 40. Determine if the headroom voltage may be below the default target headroom voltage One input to the headroom calculation unit 318 is the capacitance of the handpiece driver. C O The previously calculated voltage and frequency data for the BASE signal are also included in the calculation. A further input to the headroom calculation unit 318 is the handpiece 3 30 is the target machine current.

[0134] Based on the above input variables, the target headroom calculation unit 318 calculates the current The target headroom voltage for the amplifier when in operation is the default target headroom voltage. If the target machine current is relatively low, the calculation section 318 can lower the level of the target headroom voltage. If the target headroom voltage is too high, the calculation unit 318 can also lower the target headroom voltage. For a given target machine current, when the drive signal is relatively high, the overall handpiece impedance is This impedance is close to the maximum impedance value. This maximum impedance value is based primarily on the capacitance of the driver. This is a case where the drive signal voltage increases significantly during an arbitrarily short period of time, for example, 0.5 seconds or less. As a result, the voltage developed across the transformer primary winding 252 saturates the MOSFET. This means that the probability of the storm dropping below the value required to maintain the current level is low. The headroom voltage can be reduced. The capacitance of the driver is adjusted to the target headroom. It does not directly affect the voltage level, but rather the drive signal frequency or capacitance. If so, the calculation unit 318 determines whether the change in the voltage of the drive signal is related to the target headroom voltage. Increase your impact.

[0135] The operating condition adjusted target headroom voltage generated by the calculation unit 312 is a voltage limit voltage. In step 410, the limiter 304 is set to the target headroom voltage. 304 compares the measured headroom voltage to this target headroom voltage.

[0136] Another module executed on the processor 80 to adjust the center tap voltage of the windings. The control signal to the base voltage jump calculation unit 314 is the base voltage jump calculation unit 314. One input is the calculated voltage of the BASE signal generated by the base voltage controller 306. The second input to calculation unit 314 is the voltage level just calculated. These are the voltage levels of the BASE signal generated by the controller 306 in Based on the two voltages, the calculation unit 314 calculates the currently applied value (the voltage of the previous cycle) The voltage that will be generated across winding 252 (based on the current voltage level) is calculated by Determine the change in voltage across the primary winding 252 from the cycle-to-cycle voltage (based on the calculation). If the level is increasing, the value generated by the calculation unit 314 is positive. If the voltage level between cycles decreases, the value generated by calculation unit 314 is negative. It is.

[0137] The value generated by the calculation unit 314 is applied to the headroom adjustment module 316. The second input to module 316 is the measured headroom voltage, or HDRM signal. The magnitude of the voltage change from the voltage jump calculation unit 314 is The sum output from module 316 is the adjusted measured head voltage. The headroom voltage. If the voltage level of the BASE signal between two successive calculation cycles When increasing, the module 316 adjusts the voltage to be less than the actual measured headroom voltage. Outputs the adjusted, measured headroom voltage. Between two successive calculation cycles, When the voltage level of the ASE signal decreases, the module 316 detects the actual measured head Outputs an adjusted measured headroom voltage that is greater than the room voltage.

[0138] The regulated headroom voltage is applied to the power supply controller 324. The second input to the controller 324 is the target headroom voltage from the calculation unit 312. The controller 324 is a feedback loop controller. First, the difference between the adjusted measured headroom voltage and the target headroom voltage is determined. Based on this difference and the PID algorithm, the controller 324 determines the POWER_SUP More specifically, the controller 324 generates the PLY_CONTROL signal. The voltage applied to the center tap of the transformer 250 is such that the MOSFETs 162 and 184 are saturated. high enough to ensure that the MOSFET is not overheated as a result Adjust the POWER_SUPPLY_CONTROL signal so that the level is not too high.

[0139] The PID algorithm implemented by the controller 324 is Based on two additional variables other than the headroom voltage and the target headroom voltage, ER_SUPPLY_CONTROL signals. These variables control the A control that defines a lower and upper boundary voltage for the VAMP signal based on the current voltage. These limiting variables are separate modules that run on the processor 80. The power supply limiter 320 generates the

[0140] The input to limiter 320 is the POW previously generated by power supply controller 324. ER_SUPPLY_CONTROL signal. It will be appreciated that this voltage level of the ROL signal is proportional to the center tap voltage. Therefore, limiter 320 is a proportional regulator instead of the center tap voltage applied to transformer 250. Use the magnitude of the POWER_SUPPLY_CONTROL signal as the value to be used.

[0141] Based on this signal, which represents the current center tap voltage, as represented by Figure 17 , the limiter generates two commands to the controller 324. Specifically, in step 4 At 20, the limiter determines the maximum voltage that should next be generated by the center tap. The adjustable boost converter 88 calculates the maximum voltage level applied to the center tap. This maximum voltage must be generated because there is a limit to the rate at which the voltage can be ramped up. It is necessary to limit the rate at which the POWER_SUPPLY_CONTROL signal increases. , processor 80 forces boost converter 88 beyond its design specifications. Virtually eliminate the possibility of the power amplifier receiving a signal that would attempt to activate .

[0142] In many versions of the invention, the maximum level of change for the center tap voltage is: The center tap voltage is a constant scalar value over the range of the center tap voltage. In this case, in step 420, the POWER_SUPPLY_C The ONTROL voltage is the previous POWER_SUPPL The step 422 is performed when the limiter 320 detects the POW The instruction with this upper limit on the ER_SUPPLY_CONTROL signal is sent to Controller 3. This indicates that the message will be sent on the 24th.

[0143] In step 424, the power supply limiter 320 sets a minimum level for the center tap voltage. It is desirable to limit the rate at which the center tap voltage is allowed to drop. The reasons why this is desirable can be appreciated by understanding how the handpiece of the present invention is used. During the course of the procedure, the tip 360 is moved against the tissue on which the procedure is being performed. The handpiece is moved so that the tip 36 is repeatedly pulled in and out and pulled back. When the tip 36 is applied to tissue, the tip is subjected to a relatively large mechanical load. As the tip is pulled back away from the tissue, the mechanical load experienced by the tip decreases rapidly. As a result, the equivalent current component i flows through the mechanical components of the handpiece. M also decreased The controller 80 is configured to keep this current equivalent component constant. Therefore, when the handpiece is moved away from the tissue, the controller Lower the signal voltage and drive signal voltage V S Lower it.

[0144] This reduction in the drive signal voltage reduces the voltage that power supply 84 applies to the center tap of transformer 250. This means that the MOSFETs 162 and 184 can be significantly reduced. It is desirable to keep this voltage as low as possible to minimize heat loss through .

[0145] However, during a procedure, the handpiece tip 360 is exposed to tissue for less than 2 seconds. Hold the needle in place, pull it back away from the tissue for no more than 2 seconds, and then pull The tip is then pulled back away from the tissue for a short period of time. During this period, the power supply 84 is instructed to again significantly reduce the voltage applied to the center tap. If this occurs, when the tip head 364 is applied to the tissue again, The system then determines whether the center tap voltage is the voltage across both MOSFETs 162 and 184. There may be situations where the level is not high enough to keep the headroom voltage above the target. When the console enters this state, the base voltage limiter 304 and and base voltage controller 306 cooperate to regulate the rate at which the voltage, i.e. the drive signal voltage, is increased. This limits the location of the tip head 364 as desired by the practitioner when it is reapplied to tissue. The time it takes for the drive signal voltage to ramp up to a level that causes edge vibration is relatively long. This means that there is a possibility that

[0146] To reduce the incidence of practitioners having to wait for tip vibration to ramp up To achieve this, the power supply limiter 320 allows the power supply controller 324 to reduce the center tap voltage. Specifically, the power limiter limits the rate at which the power supply can be turned on and off in step 424. The controller 324 can generate the following POWER_SUPPLY_CONTROL In some versions of the invention, step 424 calculates the lower limit of the OL signal. The previous POWER_SUPPLY_CONTROL signal sent by the controller to the Limiter 320 This is done by subtracting a constant value from the value of the number.

[0147] In many versions of the invention, the POWER_SUPPLY_CONTROL signal level This constant value of the maximum allowable reduction in power is This is smaller than a certain value of the maximum allowable increase in the tip load. A fast response is beneficial to limit the heat dissipation through MOSFETs 162 and 184. This is because.

[0148] In step 426, the power limiter 304 determines which of the power supplies the controller is allowed to output. The power control sends a command indicating the minimum level of the POWER_SUPPLY_CONTROL signal that The data is sent to roller 306.

[0149] The voltage limit generated by the power supply limiter 304 is controlled by the power supply controller 320. It acts as an output range limiting variable for the PID algorithm being executed. The result of the calculated POWER_SUPPLY_CONTROL signal that is subsequently applied to the Then, given the current state of this signal, VAMP falls out of the voltage range for this signal. Ensure that no signal is output.

[0150] In addition, the power supply controller 324 outputs POWER_SUPPLY_CONTROL The OL signal causes the VAMP signal, which is outside the operating range of the console 50, to be Also ensure that the POWER_SUPPL The Y_CONTROL signal will result in the center tap voltage dropping below the minimum voltage level. In many cases, this minimum voltage level must not be allowed to drop below the level at which the Similarly, the controller 320 can adjust the voltage as needed. To prevent the power source from applying a voltage to the center tap that is higher than its design limit, the POWER_S Limits the UPPLY_CONTROL signal. Typically, this voltage is between 100V and 500V. Most often, this voltage limit is between 200 volts and 400 volts. In one version of the invention, this voltage is 250 volts.

[0151] The system 40 of the present invention is configured by attaching a tip 360 to a handpiece 330. A handpiece cable 326 is attached to the console 50. When the console 50 is first turned on, the processor 80 activates the memory reader 78. The data in the handpiece memory 338 is read through the By reading this data into the processor 80, you are essentially making the system ready for use. The process of preparing the stem 40 is complete.

[0152] The practitioner sets the position of the slide switch 56 or otherwise controls the display 8 The amplitude of vibration of the tip head 364 can be adjusted by inputting the appropriate command through Set it up.

[0153] The practitioner activates the handpiece by depressing a foot pedal 54 or equivalent control member. The processor 80 receives the command and operates the handpiece 330 accordingly. In response to the power supply 84 being turned on and causing the tip 360 to vibrate, the console To understand the present invention, These instructions supply the initial POWER_SUPPLY_CONT The processor 80 also outputs a ROL signal to the primary winding 252 of the transformer. It also outputs instructions that produce AC signals. For the purposes of understanding the present invention, these instructions are The E signal is output.

[0154] In response to an AC signal appearing on the transformer primary winding 252, a signal also appears on the secondary winding 258. The signal generated on the secondary winding is the drive signal. The drive signal is generated by the console 50. , and is output to the handpiece driver 338 via the cable 326. When a drive signal is applied to the driver, the driver vibrates. The driver vibration is transmitted to the horn 356 and the and through the tip stem 362 to the head 364, so that the head swings as desired. Move.

[0155] When the handpiece is in operation, the POWER_SUPPLY_CONTROL signal and the VAMP A signal proportional to the signal is applied to the DC / DC controller 90. The states of these signals Based on this, the DC / DC controller 90 selectively gates the MOSFET 112. The MOSFET 112 is gated and the controller 90 turns off the POWER_SU The VAMP signal is at a voltage determined by the PPLY_CONTROL signal. Output to the center tap.

[0156] During operation of the handpiece 330, the signal developed across the transformer primary winding 252 is The example signal is fed to both inputs of the differential amplifier 118, or more precisely, to amplifier 240. It should be understood that these signals are out of phase with each other. The components output an attenuated version of the difference between the signals to a summing amplifier 122 .

[0157] The output signal from amplifier 240 and the BASE signal are applied to the inverting input of summing amplifier 122. The two signals are combined before being added together. Ideally, these two signals are 180 degrees out of phase. In reality, the signals are not out of phase. Therefore, the summing amplifier 122 outputs the two Generates an AC signal based on the difference between the input signals. In many versions of the invention, this The signal is an amplified version of the difference between the two signals. This signal is the feedback The rectifier and splitter 138 is the feedback regulated BASE signal. The BASE signal is then split into its positive and negative components.

[0158] The negative component of the feedback regulated BASE signal is fed to an inverting voltage controlled current source 156. Based on the voltage of this signal, the current source 156 selects the MOSFET 162. Selectively turns on and off the positive component of the feedback regulated BASE signal. is the input signal to the non-inverting voltage controlled current source 174. Based on the voltage of this signal, Current source 174 selectively turns MOSFET 184 on and off. By applying a bias voltage to MOSFETs 162 and 184, the MOSFETs 162 and 184 are turned on. In fact, there is no point at which the transistor is completely turned off. This is because the voltage on the primary winding is positive. There is essentially no discontinuity or asymmetry in the rate of change of this potential when transitioning between positive and negative states. This in turn means that there is no current induced in the secondary winding 258 of the transformer. In other words, the drive signal does not have any abnormal inflections. The shape of the signal is basically a sine wave. This sine wave drive signal is sent to the handpiece driver 344. Applying a voltage ensures that the driver contracts and expands at a constant, regular rate. .

[0159] Additionally, control of the potential allowed to develop across the transformer primary winding 252 is based on two inputs. The console 50 is configured so that the first input is the BASE signal. , i.e., the signal that sets the target potential to be developed in winding 252. The second input is the The feedback signal is the actual potential across winding 252. This feature of the invention is As the voltage of the BASE signal changes, the voltage across the primary winding 252 changes accordingly. This further ensures that the secondary winding 2 varies approximately linearly with reasonable accuracy. 58, and a drive signal having relatively ideal characteristics is generated in the handpiece. Here, the relatively ideal characteristic is the signal applied to the driver 344. The drive signal then results in the tip head that the surgeon desires to perform the procedure. It has the characteristic of generating 364 vibration patterns.

[0160] Inductor 187 regulates the voltage and current across MOSFETs 162 and 184, respectively. The relatively high currents in each of the MOSFETs 162 and 194 are During periods of voltage application or relatively high current flow, the MOSFET This generates a lot more heat than when a low voltage or current is applied to the FET. By adjusting these voltages and currents, the MOSFETs 162 and 184 There are periods during which both the voltage applied and the current drawn are relatively low. This is because during these periods , serves to reduce the amount of heat generated by the MOSFET 162 or 184. Reducing the heat generated by the OSFET is achieved by the control console of the present invention. Reduce the total amount of heat generated.

[0161] The frequency tracking calculator 292 and the base frequency controller 294 are The frequency of the BASE signal output from 80 is monitored and adjusted as necessary. Assists in desired vibration of tip head 364 as the mechanical load experienced by tip 360 changes. In order to achieve a long operating time, the frequency of the drive signal must be in a proper relationship to the handpiece resonant frequency. Ensure that you do so.

[0162] The base voltage controller 306 adjusts the voltage of the BASE signal as needed. The adjustment of the tip head 364 is performed when the load of the tip head 364 changes. This is also done to ensure that 64 continues to vibrate at the amplitude desired by the practitioner.

[0163] The base voltage limiter 304 limits the MOSFET The voltage that causes T162 and 184 to move out of saturation appears on the primary winding of the transformer. This virtually eliminates the possibility of the drive signal being increased too quickly. Additionally, the drive signal may be clipped due to the MOSFET coming out of saturation. Clipping of the drive signal is permitted to occur, which can result in driver and The tip may transition from undergoing regular expansion and contraction to a less periodic motion. This clipping can also induce undesirable vibration modes within the tip. It is also possible.

[0164] Another module on the processor 80 applies a voltage to the center tap of the transformer primary winding 252. The voltage jump calculator 314 and the headroom adjuster 315 adjust the voltage of the signal to be applied. 6 together is the look forward measurement of this voltage Gives the adjusted value of headroom voltage. Look forward measurements are taken at the center of the transformer. If there is no change in the voltage applied to the tap, but there is a change in the voltage difference across the primary winding 252, This should be understood to be the value of this measurement when the power supply controller 324 is The ability to adjust the center tap voltage in anticipation of changes in voltage across the transformer winding 252 give.

[0165] This feature allows the system 40 to increase the drive voltage when the drive signal voltage is increased. is shown to increase in such a way that the center tap voltage begins to ramp up This is because the evaluation result of step 390 may be positive due to a sudden increase in the drive signal voltage. Again, in step 390, the measured headroom voltage is adjusted to match the target headroom voltage. If the drive voltage appears to drop below the ramp voltage, the processor will ramp up the drive voltage. Slow down the rate at which

[0166] When the system 40 is in a state where the drive signal voltage is reduced, this feature of the invention This helps to lower the tap voltage, which reduces heat loss through the MOSFET. Thus, the voltage drop across the terminals of the MOSFETs 162 and 184 is reduced.

[0167] A further feature of the present invention is that when the drive signal voltage drops, the power supply limiter 320 , allowing the transformer center tap voltage to decrease only at a relatively slow rate. Here, this rate of voltage reduction is limited by the power supply voltage limiter 304. It was understood that this is relatively slow compared to allowing the center tap voltage to increase. This feature of the system 40 of the present invention allows the tip head 260 to be positioned to receive the removal procedure during the procedure. It is useful when the handpiece is moved back and forth toward and away from the tissue it is attached to. During this stage of use of the tip 330, as the tip is moved towards tissue, This feature allows the drive signal voltage to be increased rapidly because the center tap voltage does not drop significantly. Ensure that there is enough headroom voltage to allow the Allowing the voltage of the drive signal to rise sharply in this manner ensures that tip 364 is initially This reduces the energy loss that occurs when the catheter is pressed against tissue.

[0168] When the system 40 of the present invention is in a specific operating state, the target headroom voltage calculation unit 3 12 lowers the target headroom voltage from its default level. The console will automatically reset the target headroom voltage when the system 40 is in these states. Adjust the center tap voltage to the voltage that must be maintained when at fault level. This feature of the invention must also be maintained in MOSFETs 162 and 184. Lowering the voltage level that cannot be tolerated and reducing the undesirable effects of holding this voltage at a high level do.

[0169] Furthermore, the linear amplifier 115 of the present invention produces very little distortion over a relatively wide range of frequencies. Many versions of the invention allow the amplification of the BASE signal without introducing In this case, the console can output a drive signal of 15 kHz to 45 kHz. In the more preferred version, the console will generate a drive signal of 10kHz to 100kHz. The output can be distortion-free or with an acceptable level of distortion. The system of the present invention is an ultrasonic handpiece to which a drive signal having multiple components is applied. More specifically, the console of the present invention is suitable for driving the It is possible to generate drive signals whose individual components differ in frequency by more than 2000 Hz. do.

[0170] The above description is directed to a specific embodiment of the system 40 of the present invention.

[0171] Alternative versions of the invention are possible. For example, each of the above features may be incorporated into the system of the invention. It is not necessary for each version of the system to include a Class A amplifier, a Class B amplifier, or a Class AB amplifier. Amplifiers or variations of these amplifiers and a constant voltage is applied to the center tap of the transformer primary winding. It is within the scope of the present invention to provide a power supply for the console. The system shall contain one or two class A amplifiers, or one or two class B amplifiers. can be done.

[0172] The console monitors the headroom voltage and adjusts the center tap based on the headroom voltage. In a version of the invention that regulates the loop voltage, all of the features of the disclosed system are present. Therefore, alternate versions of the system may not be The headroom voltage is then calculated using a look-forward function of the winding voltage before being compared to the target headroom voltage. In some versions of the invention, the target head may not be adjusted based on changes in head position. The headroom voltage may be a constant value.

[0173] Similarly, some versions of the console 50 may have the processor 80 turn primary winding 2 A model such as a full-scale voltage calculator 298 that reduces the maximum voltage that can appear on the input of the It is possible to configure the device so that there is no need to provide a separate module.

[0174] The structure of the features of the invention may also vary from that described. Bipolar transistors may be used in place of one or more of the T's. While this is happening, a voltage of over 150 volts peak is generated across the transformer primary winding 252. If so, a MOS transistor may be used to selectively connect the winding to ground or to an effectively open circuit. FETs are considered the preferred form of active resistor. Amplifiers, rectifiers and splitters , the current source, as well as the power supply that provides the VAMP signal to the center tap of the transformer, are described. It may have a different structure than that shown.

[0175] In the described version of the invention, the headroom monitor 190 is connected to the MOSFET 16 The present invention is configured to monitor the voltage present between the drains of the transistors 2 and 184 and ground. In an alternative version of the invention, the headroom monitor is connected to the MOSFETs 162 and 184. The drain-source voltage can be monitored. In the version of the present invention where the transistor acts as an active resistor, this type of head loop The system monitor monitors the collector-emitter voltage across the transistor.

[0176] One such headroom voltage monitoring circuit will now be described with reference to FIG. This circuit can monitor the headroom voltage as described with reference to FIG. Some of the components of the circuit in FIG. 6A are included in the circuit in FIG. To avoid redundancy in this document, the components described above are referred to herein as , which will be explained again only to a minimum. The input. In the circuit of FIG. 18, similar to the circuit of FIG. 6A Additionally, the anodes of diodes 196 and 198 are connected to the non-inverting input of amplifier 212 . The anodes of diodes 196 and 198 are connected to amplifier 212 through resistor 204. The reference voltage Vref is applied to the inverting input of amplifier 212 through resistor 452. In some versions of the invention, the voltage V ref Constant voltage of 15VDC~30VDC Voltage V ref The circuitry within console 50 that generates the Capacitor 454 is not part of V ref The rail where the diode 196 and A resistor 456 is connected between the junction of capacitor 198 and resistor 204. 54 in parallel.

[0177] Diode 458 and resistor 460 couple the inverting input of amplifier 212 to the output of the amplifier. More specifically, the anode of diode 458 is connected in parallel between amplifier 212 and It has its cathode connected to the junction of the amplifier and resistor 214 .

[0178] The circuit of FIG. 18 also uses the voltages at the sources of MOSFETs 162 and 184 as inputs. Each of these voltages is applied to a unity gain amplifier circuit that acts as a rectifier. The amplifier circuit to which the signal present at the source of MOSFET 162 is applied is amplifier 4. 64. The signal present at the source of MOSFET 162 is coupled to the non-inverting input of amplifier 464. The resistor through which the voltage is applied to the non-inverting input of amplifier 464, or The capacitor connected between the input and ground is not shown. The cathode of diode 466 is connected to the inverting input of amplifier 464. The output signal of the amplifier 464 is connected to the output of the diode 466 through a resistor 468. The voltage is applied to the anode of the electrode 470.

[0179] The source of MOSFET 184 is connected to the same type of MOSFET 162. is connected to the rectifier.

[0180] Any signal present at the cathode of diode 470 is applied to the non-inverting input of amplifier 480. A capacitor 472 is connected between the junction of diode 470 and the input of amplifier 480. A resistor 474 is connected in parallel across the capacitor 472. The output signal of 480 is applied back to the inverting input of the amplifier. The signal is applied through another resistor 462 to the inverting input of each of the amplifiers 464 .

[0181] The output signal of amplifier 480 is applied through resistor 482 to the inverting input of amplifier 230. Thus, the input to the non-inverting input of amplifier 230 is connected to MOSFETs 162 and 18. The input to the inverting input of amplifier 230 is This is the higher of the two peak voltages that appear at the sources of MOSFETs 162 and 184. The output of the amplifier 230 is the minimum of these drain voltages and the This is the difference between the higher of the source voltages of resistor 231 and capacitor 236 and the HEADROOM voltage output by the circuit of FIG. It's a signal.

[0182] In some versions of the invention, the signal gain of the individual subcircuits of the amplifier is It may be lower or higher than the gain.

[0183] Alternative assemblies for monitoring the headroom voltage are possible. In another version of the invention, an analog circuit generates the HDRM signal. The analog circuit includes a FET replacing the resistor placed across the capacitor 192. In each control loop cycle, the capacitor 192 is discharged. The capacitor is switched on only once. This is measured in the transistor This increases the response rate of the headroom monitoring circuitry to voltage changes. can be used to provide a reference voltage that is applied to the inverting input of amplifier 230. Therefore, the voltage can be provided by a digital-to-analog converter. This is useful in versions of the invention where it may be desirable to change the potential of In another version of the invention, the collector and drain of the switching transistor are digitally The modules executed on the processor are and generating an HDRM signal based on the evaluation.

[0184] Similarly, the control processes running on the console processor 80, i.e., the control modules The module may operate in a different manner than that described.

[0185] The present invention relates to an ultrasonic transducer that calculates the voltage and frequency of a drive signal using an equation based on equations (1) to (3). The present invention is not limited to sonic tool systems. Without relying on comparisons based on either the applied voltage, the drive signal frequency, or the equivalent component of the machine current , the voltage and frequency of the drive signal can be determined.

[0186] For example, in some versions of the present invention, the default target headroom voltage is A lower possible target headroom voltage may be used. Based on the system operating conditions, the headroom voltage calculation unit calculates the headroom voltage. This configuration of the present invention selectively increases the MOSFET 1 The voltage drops across 62 and 184 keep transistors 162 and 184 in saturation. can be further reduced beyond the value required for

[0187] In some versions of the invention, the headroom adjuster simply adjusts the measured headroom As a result of this version of the system, The center tap voltage exceeds the value required to hold up MOSFETs 162 and 184. It will be appreciated that in some cases, the benefits of this version of the invention are that the adjusted measured The aim of the present invention is to reduce the time required to generate a given headroom value.

[0188] In some versions of the invention, a power supply limiter 320 limits the current voltage of the VAMP signal is multiplied by a constant factor to obtain the POWER_SUPPLY_CONTROL signal. In yet another version of the invention, the power supply limiter Either 320 or the power supply controller 324 detects that the voltage of the drive signal is reduced. Shortly after this occurs, the controller 324 reduces the voltage applied to the center tap of the transformer. For example, in some versions of the invention, console 5 0 indicates that the voltage of this signal is reduced from the point when the console starts to reduce the drive signal. It is configured to prevent the discharge for 1 to 5 seconds. The advantage of this configuration is that the tip head During the step in the procedure where the 364 is reapplied to the bone, the center tap voltage clearly The aim is to achieve a voltage that allows the capacitor to rapidly increase the voltage of the drive signal.

[0189] In some versions of the invention, the power supply controller 324 In the main PID control algorithm to calculate the next value of the LY_CONTROL signal In some cases, the voltage limit output by the power supply limiter 320 is not used. In these versions of the invention, the power supply controller 324 first calculates the POWER The R_SUPPLY_CONTROL signal is compared to a voltage limit. If the SUPPLY_CONTROL signal is within the voltage limits, the first calculated PO The WER_SUPPLY_CONTROL signal is output to the boost converter 88. POWER_SUPPLY_CONTROL. The first calculated POWER_SUP If the PLY_CONTROL signal goes out of voltage limits, two things can happen: In some versions of the invention, one of these may occur: The closest voltage limit is output as the LY_CONTROL signal.

[0190] In another version of the invention, the power supply controller 324 uses a PID control algorithm. Rerun. In this run of the PID control algorithm, the voltage limit is the target headroom. The advantage of this version of the invention is that the individual Each execution performs a step to limit the POWER_SUPPLY_CONTROL signal. However, the POWER_SUPPLY_CONTROL signal is not included in the voltage control. It is understood that if there is a need to limit the PID algorithm, two runs will be performed. The first run will be the initial POWER_SUPPLY_CONTROL signal, i.e. The center tap voltage is prevented from falling outside the limits set by the power supply voltage limiter 320. The second execution of the algorithm results in a signal indicating the boost voltage being determined. Generates a POWER_SUPPLY_CONTROL signal that ensures that the supply voltage is within the specified limits. do.

[0191] Thus, all of the disclosed software modules executing on processor 80 It is understood that the For example, in the disclosed version of the invention, a transistor that functions as an active resistor is Heat dissipation through the transistors MOSFETs 162 and 184 is not a significant concern. There may be various configurations of the invention. In other versions, the center tap voltage can be held constant. The voltage applied to the center tap voltage may be changed, but the voltage is relatively Higher minimum voltage levels, such as a minimum voltage of 25 volts or, in some cases, a maximum voltage of 50 volts or more. In these versions of the invention, the transformer can be set to have a small voltage. The voltage present at the drain or collector of a transistor is always saturated. This means that To ensure that the amplifier is in this state, a voltage limiter 304 limits the voltage of the BASE signal. This eliminates the need to limit the increase in the voltage level. This makes the presence of the power limiter mentioned above unnecessary. It may be possible to do so.

[0192] In versions of the invention where the center tap voltages are constant, the voltages that generate these voltages are The source does not have to be a variable power supply. This means that the DC voltage of the signal produced by this power supply can be This eliminates the need for software to be installed for configuration.

[0193] For purposes of the present invention, the voltage applied to the center tap of the transformer primary winding 252 is It is understood that the DC voltage is a voltage above ground. For any design considerations, this may be the case even if the voltage levels change at a constant frequency. The voltage at can be considered to be constant.

[0194] Some of the present invention's center tap voltages are adjusted to ensure adequate headroom voltage. Some versions may not include the circuitry that generates an indication of headroom voltage. In these versions of the invention, the virtual value of the headroom voltage is Calculated as a function of the voltage and / or drive signal current.

[0195] In some versions of the invention, the resistor attached to the secondary winding of the transformer The voltage provides a signal on which at least one of the drive signal voltage and the drive signal current is based. do.

[0196] Additionally, the present invention is not limited to amplifiers in which the boost converter functions as a variable DC voltage power supply. No. One alternative power source is the buck converter.

[0197] Alternative control consoles that do not include all of the inventive features of console 50 described above. Therefore, some consoles of the present invention may use the linear amplification of the present invention. may include a 100mV ... Similarly, the headroom voltage measurement circuit of the present invention can be implemented without using the linear amplifier. There may be versions of the invention of which it may be desirable to utilize one .

[0198] The amplifier of the present invention is a voltage controlled current source rather than a voltage controlled voltage source. In these versions of the invention, a voltage is typically applied to the primary winding of the transformer. There is no need to provide a feedback loop to regulate the voltage of the applied signal.

[0199] Similarly, the control console 50 of the present invention may be used to control power generating components other than ultrasonic drivers. Surgery other than handpieces with power generating units It should be appreciated that an AC drive signal can be provided to the tool. The AC drive signal can be applied using a voltage regulator, and the power generation section responds to the application of the drive signal by It emits light (photon energy) or some form of mechanical energy other than ultrasonic energy. Alternatively, the power generating portion may be an electrode, and the electrode The device applies a drive signal in the form of RF energy to the tissue to which the electrode is applied. In acupuncture procedures, electrical energy is applied to tissue in a way that converts the electrical energy into heat. The application of heat produces the desired therapeutic effect on the tissue. The effect is the ablation of tissue.

[0200] Additionally, the transformer and associated linear amplifier of the present invention may be used in applications other than medical or surgical related work. A drive signal used to power a device used to perform the work of It is possible to apply it to generate

[0201] It is, therefore, the object of the appended claims to include all such modifications as come within the true spirit and scope of the invention. It is intended to encompass such modifications and variations.

Claims

1. A controller that supplies an AC drive signal to the power generating unit (344) of the surgical power tool (330). A sole (50), a primary winding (252) having a center tap and both ends to which a DC voltage is applied; A secondary winding (258) on which the drive signal is induced for application to the power generating section (344) of the tool. A transformer (250) comprising: a primary winding (252) of the transformer for generating an AC voltage across the primary winding; A circuit (115) for grounding or opening both ends of the having The circuit that connects both ends of the primary winding (252) of the transformer to ground or open circuit is A number of transistors (164, 165) function as active resistors between each end of the winding and ground. 84), The linear transformer controls the first winding based on an external control signal and a voltage across the primary winding. The resistance of the active resistor is set to set the voltage across the secondary winding. Sole.

2. The linear amplifier (115) detects the voltage across the primary winding (252) of the transformer. A differential amplifier (240) to which The differential amplifier outputs a signal based on the difference in voltage across the primary winding of the transformer.

2. The control console (50) of claim 1, wherein the control console (50) generates as a feedback signal 。

3. The linear amplifier (115) further receives the feedback from the differential amplifier (240). The resistors of the transistors (162, 184) are controlled in combination with the external control signal.

3. The control console (50) of claim 2, for generating a signal to regulate

4. The linear amplifier (115) further receives the feedback from the differential amplifier (240). combining the external control signal with the The linear amplifier is configured such that the combined feedback signal and the external control signal a rectifier and splitter (138) to which the Separating the combined signal into positive and negative components, The negative component of the signal sets the resistance of a first one of the transistors (162). the positive component of the combined signal is used to 4. The resistor of claim 2 or 3, which is used to set the resistance of the second transistor (184) of The control console (50) described herein.

5. The linear amplifier (115) A first winding of the transformer is turned on based on the feedback signal and the external control signal. The resistance of a first transistor (162) of the transistors connected to the first end is a first voltage controlled current source generating a current to be set; A first winding of the transformer is turned on based on the feedback signal and the external control signal. The resistance of the second transistor (184) of the transistors connected to the second end a second voltage controlled current source for generating a current to be set; A control console (50) according to any one of claims 1 to 5, comprising:

6. The linear amplifier (115) includes a splitter (138), which outputs a positive output a feedback regulated external control signal having positive and negative components; The negative component of the clock-adjusted external control signal is fed to the first voltage-controlled current source (156). a positive component of the feedback regulated external control signal as a second voltage 7. The control circuit of claim 6, wherein the control signal is provided as a control signal to a voltage controlled current source (174). Console (50).

7. A power supply (8) that supplies a variable DC voltage to the center tap of the primary winding (252) of the transformer. 4) and The voltage across the transistors (164, 184) is monitored. a headroom monitor (190) for generating a signal representative of the voltage The headroom monitor indicates the voltage across the transistors (162, 184). a power supply connected to said power supply for receiving a signal from said power supply and for adjusting a DC voltage provided by said power supply; , a primary winding (25) of the transformer is connected from the power source based on the voltage across the transistor. 2) a power supply controller (324) for setting the level of DC voltage supplied to the The control console (50) of any one of claims 1 to 6, further comprising:

8. The headroom monitor (190) receives as input: When the transistor is a FET, the current at the drain and source of the FET is Receives pressure, When the transistor is a bipolar transistor, 8. The control circuit of claim 7, wherein the control circuit receives a voltage at the collector and emitter of the Console (50).

9. The DC power supply (84) A DC constant voltage supply (86); A DC voltage is applied from the DC constant voltage supply source, and the power supply controller (190) A DC variable voltage is applied to the center tap of the primary winding (252) of the transformer in response to a control signal from the A boost converter (88) for applying a pressure 9. A console (50) according to claim 7 or 8, comprising:

10. The transistor of the linear amplifier (115) functioning as the active resistor is a MOS A console (5) according to any one of claims 1 to 9, which is a FET (162, 184). ０）。

11. The transformer (250) is connected to at least one driver of the ultrasonic surgical tool (330). The present invention relates to a drive signal output device for outputting a drive signal to be applied to a drive unit (344). A control console (50) as described in paragraph 1.

12. The linear amplifier (115) is independent of the feedback signal and the external control signal. In addition, the front end of the transistor (162, 184) is set to a saturation mode so that each of the transistors (162, 184) is always in saturation mode. A method according to any one of claims 1 to 11, wherein a signal is applied to each of the transistors. On-board control console (50).

13. Controlling the supply of an AC drive signal to the power generating unit (344) of the surgical power tool (330) A console (50), a primary winding (252) having a center tap and both ends to which a DC voltage is applied; A secondary winding (258) on which the drive signal is induced for application to the power generating section (344) of the tool. A transformer (250) comprising: A transformer is connected to the primary winding of the transformer and to ground so as to generate an AC voltage across the primary winding. a transistor (162, 184) that is selectively turned on or off; A DC voltage level adjusting circuit for adjusting the level of the DC voltage applied to the center tap of the primary winding of the transformer. Variable Power Assembly and Equipped with The transistors (162, 184) act as active resistors; The transistors (162, 18) connected to the ends of the primary winding (252) of the transformer A headroom monitor (190) is connected to the end of the headroom monitor (190), and the headroom monitor determining a headroom voltage for the transistor based on a voltage at the end of the transistor; generating a headroom signal representing The DC variable power supply receives the headroom signal from the headroom monitor. and a processor (80) for controlling the variable power supply based on the headroom signal. A voltage is applied to the center tap of the primary winding of the transformer so that a saturation voltage is applied to the transistor. A control console which sets the level of the DC voltage applied to the power supply.

14. The headroom monitor (190) further monitors the voltage across the transistor. a first end of the transistor and a second end of the transistor; a headroom voltage based on a difference between a voltage at a second end opposite the first end; 14. The control console (50) of claim 13, for generating a signal representative of

15. A voltage level applied to the transistor is adjusted to adjust the level of the voltage across the primary winding of the transformer. a controller (80, 115) for adjusting the applied current; The DC variable power supply processor (80, 312) further comprises a primary winding (252) of the transformer. Receives a signal from the controller representative of a voltage to be applied to a primary winding of a transformer. A voltage applied to the center tap of the primary winding of the transformer based on the change in the voltage across the 15. A control controller according to claim 13 or 14, which sets the level of the DC voltage applied to the Sole.

16. The DC variable power supply processor (80, 312) further comprises a primary winding (252) of the transformer. The controller (80, 115) notifies the user that the voltage to be applied to the When these signals indicate that the voltage across the primary winding (252) of the transformer is reduced, A D applied to the center tap of the primary winding of the transformer at a rate slower than 16. The control console of claim 15, which reduces the level of the C voltage.

17. the transistor is a FET (162, 184); The headroom monitor (190) detects one of the two drain voltages of the transistor. and the higher of the two peak voltages at the source of the transistor. According to any one of claims 13 to 16, a signal representative of a headroom voltage is generated based on the A control console (50) as claimed in any one of the preceding claims.

18. At each connection between the transistors (162, 184) and the primary winding (252) of the transformer The headlamp is connected to a diode (196, 198) in reverse bias such that the voltage at the a diode between the anodes of the diodes is connected to each other; A constant voltage is applied to the junction, and the voltage at the junction between the anodes of the diodes is the lower of two voltages between the transistor and the primary winding of the transformer; The voltage is used as the voltage at the first end of the transistor.

8. A control console (50) as described in any one of claims 7.

19. The ends of the transistors (162, 184) that are distal from the primary winding of the transformer The head is arranged so that the voltage at the head is applied to a plurality of forward biased diodes (470). A room monitor is configured, the cathodes of the plurality of diodes are connected to a connection portion, The voltage at the junction of the plurality of diodes (470) is a first terminal of the transistor. The control console according to any one of claims 13 to 18, rule (50).

20. The transformer (250) is connected to at least one driver of the ultrasonic surgical tool (330).

20. The method according to claim 13, further comprising the step of: outputting a drive signal to be applied to the actuator (344). The control console (50) of any preceding claim.

21. An AC drive signal is provided to the driver (344) of the ultrasonic surgical handpiece tool (330). A console (50) for providing a primary winding (252) having a center tap and both ends to which a DC voltage is applied; A secondary winding (258) on which the drive signal is induced for application to the power generating section (344) of the tool. A transformer (250) comprising: A voltage source is connected between the primary winding of the transformer and ground to generate an AC voltage across the primary winding. Transistors (162, 184) that are selectively turned on or off to having The control assembly (80, 115) configures the transistor to function as an active resistor. In this way, the signal applied to the base or gate of the transistor (162, 184) is changed. 、 One end of the inductor (187) is connected to the first transistor (162) and the primary winding of the transformer. The other end of the inductor is connected to the connection with the first end of the line (252), and the other end of the inductor is connected to the connection with the second transistor. a connection between the transistor (184) and the second end of the primary winding of the transformer; If the inductor is in parallel with the handpiece driver (344), The circuit has a resonant frequency within 50% of the resonant frequency of the handpiece. The inductor has an inductance.

22. A controller that supplies an AC drive signal to the power generating unit (344) of the surgical power tool (330). A sole (50), a primary winding (252) having a center tap and both ends to which a DC voltage is applied; A secondary winding (258) on which the drive signal is induced for application to the power generating section (344) of the tool. A transformer (250) comprising: A voltage source is connected between the primary winding of the transformer and ground to generate an AC voltage across the primary winding. a transistor (162, 184) selectively turned on or off to A variable resistor is provided to adjust the level of the DC voltage applied to the center tap of the primary winding of the transformer. DC power assembly Equipped with The transistors (162, 18) connected to the ends of the primary winding (252) of the transformer A headroom monitor (190) is connected to the end of the headroom monitor (190), and the headroom monitor determining a headroom at the transistor based on a voltage at the end of the transistor; generating a signal representative of a voltage; The control circuit (80, 115) pre-configures the transistor to function as an active resistor. A variable current is applied to the transistor, and the control circuit outputs a headroom signal from the headroom monitor. a headroom signal and a current applied to the resistor based on the headroom signal; adjusting a current applied to the transistor based on the headroom signal; A console for selectively limiting the voltage across the primary winding of the transformer.

23. The headroom monitor (190) further comprises: a voltage at a first end of the transistor and a voltage at a front end of the transistor; determining a headroom voltage based on a difference between a voltage at a second end opposite the first end; 23. The control console (50) of claim 22, which generates a signal representative of

24. the transistor is a FET (162, 184); The headroom monitor (190) detects one of the two drain voltages of the transistor. and the higher of the two peak voltages at the source of the transistor.

24. The method according to claim 22 or 23, further comprising generating a signal representative of a headroom voltage based on The control console (50) described herein.

25. At each connection between the transistors (162, 184) and the primary winding (252) of the transformer The headlamp is connected to a diode (196, 198) in reverse bias such that the voltage at the A monitor is configured such that the anodes of the diodes are connected together, and The voltage at the anode-to-anode connection is connected between the transistor and the primary winding of the transformer. A constant voltage is applied to the connection between the anodes so that the voltage at the anode is the lower of the two voltages at the anodes. and this voltage is used as the voltage at the first end of the transistor. A control console (50) according to any one of clauses 22 to 24.

26. The ends of the transistors (162, 184) that are distal from the primary winding of the transformer The head is arranged so that the voltage at the head is applied to a plurality of forward biased diodes (470). A room monitor is configured, the cathodes of the plurality of diodes are connected to a connection portion, The voltage at the junction of the plurality of diodes (470) is a first terminal of the transistor. The control console according to any one of claims 22 to 25, rule (50).

27. The transformer (250) is connected to at least one driver of the ultrasonic surgical tool (330). Any one of claims 22 to 26, which outputs a drive signal to be applied to the switch (344). The control console (50) of any preceding claim.

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