Control of ultrasonic handpieces

Abstract

A system and method for controlling vibration of an ultrasonic handpiece generates an AC drive signal that is applied to a transducer of the ultrasonic handpiece to vibrate the tip of the ultrasonic handpiece. A stiffness characteristic of tissue contacted by the vibrating tip is determined based on the measured voltage and current of the AC drive signal. A target tip displacement is determined based on the tissue characteristics, and the AC drive signal is adjusted to achieve the determined target displacement.

Description

[Background technology]

[0001] Ultrasonic handpieces used for surgical procedures can typically cut through various different types of tissue. However, in many surgical procedures, the surgeon wants to cut through only certain types of tissue while leaving other types intact. [Overview of the Initiative]

[0002] According to a first embodiment, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console comprises a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. A processor is configured to determine a characteristic relating to the stiffness of the tissue in contact with the vibrating tip in response to the signal generator supplying the AC drive signal to the ultrasonic handpiece and vibrating the tip. The processor is then configured to adjust the AC drive signal output by the signal generator based on the determined characteristic.

[0003] According to a second aspect, a method for operating the control console of the first aspect and / or performing the functions of the control console is provided.

[0004] Any of the above embodiments can be implemented using any of the following embodiments.

[0005] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0006] In one embodiment, the control console includes a sensor for measuring the voltage of the AC drive and a sensor for measuring the current of the AC drive signal. A processor is coupled to the sensors and is configured to determine the tissue stiffness value of the tissue contacted by the tip based on the measured current and voltage of the AC drive signal, and to adjust the AC drive signal output by the signal generator based on the tissue stiffness value.

[0007] According to a third embodiment, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console comprises a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further comprises a sensor for measuring the voltage of the AC drive signal, a sensor for measuring the current of the AC drive signal, and a processor coupled to the sensors and the signal generator. The processor is configured to determine a first displacement level of the tip, which is the maximum displacement level of the tip, and to receive a tissue response model that defines a stiffness threshold and a second displacement level of the tip, which is associated with different potential tissue stiffness values, each of which is smaller than the first displacement level and larger than the stiffness threshold in the tissue response model. The processor is further configured to determine the tissue stiffness value of the tissue in contact with the tip, based on the measured voltage and current of the AC drive signal, and to determine whether the determined stiffness value is smaller than or greater than the stiffness threshold. The processor is further configured to set the target displacement level of the tip of the ultrasonic handpiece to a first displacement level in response to determining that the determined stiffness value is less than the stiffness threshold, and to set the target displacement of the tip to a second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value in response to determining that the stiffness value is greater than the stiffness threshold. The processor is further configured to adjust the AC drive signal output by the signal generator to achieve the set target displacement level.

[0008] According to a fourth aspect, a method for operating the control console of the third aspect and / or a method for performing the functions of the control console are provided.

[0009] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0010] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0011] In one embodiment, the processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal as a determined tissue stiffness value, the stiffness threshold is defined by the mechanical resistance threshold, and the potential tissue stiffness value is defined by the potential mechanical resistance of the ultrasonic handpiece.

[0012] In one embodiment, the processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal by determining the capacitance of the transducer of the ultrasonic handpiece, determining the resonant frequency of the ultrasonic handpiece, setting the frequency of the AC drive signal to the determined resonant frequency of the ultrasonic handpiece, calculating the current flowing through the mechanical components of the ultrasonic handpiece based on the capacitance of the transducer, the frequency of the AC drive signal, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, and calculating the mechanical resistance of the ultrasonic handpiece based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal.

[0013] In one embodiment, the tissue response model defines a second displacement level such that the second displacement level decreases as the potential tissue stiffness value increases.

[0014] In one embodiment, the stiffness threshold is a first stiffness threshold, the tissue response model defines a third tip displacement level which is the minimum non-zero tip displacement level, each less than a second displacement level, and a second stiffness threshold which is greater than the potential tissue stiffness value. The processor is configured to set the target tip displacement level to the third displacement level in response to the determined tissue stiffness value being greater than the second stiffness threshold, and to set the target tip displacement level to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value in response to the determined tissue stiffness value being greater than the first stiffness threshold and less than the second stiffness threshold.

[0015] In one embodiment, at least one of the following is based on user settings: a first displacement level, a second displacement level, a third displacement level, a first stiffness threshold, a second stiffness threshold, or the relationship between the second displacement level and the potential structural stiffness value.

[0016] In one embodiment, the relationship between a second displacement level and a potential structural stiffness value is defined by a negative linear function that maps a first stiffness threshold to a first displacement level and a second stiffness threshold to a third displacement level.

[0017] In one embodiment, the relationship between a second displacement level and a potential structural stiffness value is defined by a decreasing curve function that maps a first stiffness threshold to a first displacement level and a second stiffness threshold to a third displacement level.

[0018] In one embodiment, the tissue response model is configured to reduce tissue type ablation during the operation of the ultrasonic handpiece, and the relationship between a second displacement level and a potential tissue stiffness value is defined by a curve-declining function based on the voltage of the AC drive signal corresponding to the tissue type puncture.

[0019] In one embodiment, the curve reduction function is further based on the resistance offset corresponding to the vibration components of the ultrasonic handpiece.

[0020] In one embodiment, the tissue response model is a first tissue response model, and the control console further includes memory for storing the first tissue response model and a second tissue response model configured to ablate tissue harder than the first tissue response model. The processor is configured to receive user selections of the first and second tissue response models via a user interface. The processor is configured to set the target displacement level to a first displacement level in response to the user selection of the first tissue response model and in response to the tip being positioned against a first tissue type, and to set the target displacement level to a displacement level less than the first displacement level in response to the user selection of the first tissue response model and in response to the tip being positioned against a second tissue type harder than the first tissue type. The processor is further configured to set the target displacement level to a first displacement level in response to the user selection of the second tissue response model and in response to the tip being positioned against both the first and second tissue types.

[0021] In one embodiment, the stiffness threshold is a first stiffness threshold, the latent tissue stiffness value is a first latent tissue stiffness value, the second tissue response model defines a second stiffness threshold greater than the first stiffness threshold, associates each of the second displacement levels with a different second latent tissue stiffness value greater than the second stiffness threshold, and at least one of the first latent tissue stiffness values ​​is less than each of the second latent tissue stiffness values.

[0022] In one embodiment, the relationship between a second displacement level and a second potential tissue stiffness value is defined by a function based on the voltage of the AC drive signal corresponding to puncturing a third tissue type that is stiffer than the second tissue type.

[0023] In one embodiment, the target displacement level of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the processor is configured to adjust the AC drive signal output by the signal generator to achieve the set target displacement level by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece.

[0024] According to a fifth aspect, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console comprises a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further comprises a processor coupled to the signal generator. The processor is configured to activate a stall mode in which the displacement of the tip of the ultrasonic handpiece caused by the ultrasonic handpiece is non-zero and insufficient to ablate the tissue in contact with the tip, and to maintain the resonant frequency of the ultrasonic handpiece while the stall mode is active.

[0025] According to the sixth aspect, a method for operating the control console of the fifth aspect and / or a method for performing the functions of the control console are provided.

[0026] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0027] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0028] In one embodiment, the processor is configured to receive user input indicating a tissue type that is to be kept intact, and to activate a stall mode in response to the tip being positioned relative to the tissue type during tip vibration by the control console.

[0029] In one embodiment, the control console further includes a sensor for measuring the voltage of the AC drive signal and a sensor for measuring the current of the AC drive signal. The processor is configured to determine a tissue stiffness value based on the measured voltage and current of the AC drive signal, to determine whether the tissue stiffness value is greater than a stiffness threshold, and to activate stall mode in response to the determination that the tissue stiffness value is greater than the stiffness threshold.

[0030] In one embodiment, the stiffness threshold is defined by a mechanical resistance threshold, and the processor is configured to determine the mechanical resistance of the ultrasonic handpiece as a tissue stiffness value based on the measured voltage and current of the AC drive signal.

[0031] In one embodiment, the processor is configured to determine a second mechanical resistance of the ultrasonic handpiece based on a second voltage and current of the AC drive signal measured by a sensor when stall mode is active; to determine whether the second mechanical resistance is below a stiffness threshold; and, in response to the determination that the second mechanical resistance is below a stiffness threshold, to deactivate stall mode, adjust the AC drive signal output by the signal generator, and to ensure that the tip displacement caused by the adjusted AC drive signal is at a maintained resonant frequency and can ablate the tissue in contact with the tip.

[0032] According to a seventh aspect, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console includes a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further includes a sensor for measuring the voltage of the AC drive signal, a sensor for measuring the current of the AC drive signal, and a processor coupled to the sensors and the signal generator. The processor is configured to determine the characteristics of the ultrasonic handpiece associated with the tissue contacted by the tip based on the measured voltage and current of the AC drive signal, to determine a target displacement of the tip based on the determined characteristics and a puncture voltage corresponding to the tissue contacted by the tip, and to adjust the AC drive signal output by the signal generator to achieve the determined target displacement of the tip.

[0033] According to the eighth aspect, a method for operating the control console of the seventh aspect and / or a method for performing the functions of the control console are provided.

[0034] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0035] According to one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0036] According to a ninth aspect, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console includes a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further includes a sensor for measuring the voltage of the AC drive signal, a sensor for measuring the current of the AC drive signal, a memory for storing a first tissue response model and a second tissue response model configured to ablate tissue harder than the first tissue response model, and a processor coupled to the sensors, the memory, and the signal generator. The processor is configured to determine a first displacement level of the tip, which is the maximum displacement level of the tip, and to receive user selections of the first and second tissue response models via a user interface. The processor is further configured to set the target displacement level of the tip to a first displacement level in response to a user selection of a first tissue response model and in response to the tip being positioned relative to a first tissue type, and to set the target displacement level to a second displacement level that is less than the first displacement level in response to a user selection of a first tissue response model and in response to the tip being positioned relative to a second tissue type that is harder than the first tissue type. The processor is further configured to set the target displacement level to a first displacement level in response to a user selection of a second tissue response model and in response to the tip being positioned relative to both the first and second tissue types. The processor is further configured to adjust the AC drive signal output by the signal generator to achieve the set target displacement level of the tip.

[0037] According to the tenth aspect, a method for operating the control console of the ninth aspect and / or a method for performing the functions of the control console are provided.

[0038] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0039] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0040] According to an eleventh aspect, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console includes a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further includes a sensor for measuring the voltage of the AC drive signal, a sensor for measuring the current of the AC drive signal, and a processor coupled to the sensors and the signal generator. The processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal, to determine a target displacement of the tip based on the mechanical resistance, and to adjust the AC drive signal output by the signal generator to achieve the determined target displacement of the tip.

[0041] According to the twelfth aspect, a method for operating the control console of the eleventh aspect and / or a method for performing the functions of the control console are provided.

[0042] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0043] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0044] In one embodiment, the processor is configured to determine a target displacement of the tip such that, in response to the determined mechanical resistance of the ultrasonic handpiece representing an increased mechanical resistance of the ultrasonic handpiece, the target displacement represents a decreased displacement of the tip.

[0045] In one embodiment, the processor is configured to determine a target displacement of the tip such that, in response to the determined mechanical resistance representing an increased mechanical resistance of the ultrasonic handpiece and the determined mechanical resistance being greater than a mechanical resistance threshold, the target displacement represents a decreased displacement of the tip, and in response to the determined mechanical resistance being less than a mechanical resistance threshold, the target displacement represents a maximum displacement level of the tip.

[0046] In one embodiment, the processor is configured to determine the capacitance of the transducer of the ultrasonic handpiece, determine the resonant frequency of the ultrasonic handpiece, set the frequency of the AC drive signal to the determined resonant frequency of the ultrasonic handpiece, calculate the current flowing through the mechanical components of the ultrasonic handpiece based on the capacitance of the transducer, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, and calculate the mechanical resistance of the ultrasonic handpiece based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal.

[0047] In one embodiment, the processor is configured to receive a microstructure response model that defines the target displacement of the tip as a function of mechanical resistance, and to determine the target displacement of the tip based on the microstructure response model and mechanical resistance.

[0048] In one embodiment, the tissue response model defines a decreasing tip displacement level over increasing mechanical resistance values.

[0049] In one embodiment, the tissue response model defines a maximum tip displacement level associated with a first mechanical resistance threshold, a minimum tip displacement level associated with a second mechanical resistance threshold greater than the first mechanical resistance threshold, and an intermediate tip displacement level between the maximum tip displacement level and the minimum tip displacement level, associated with an intermediate mechanical resistance value between the first and second mechanical resistance thresholds, wherein the intermediate tip displacement level decreases over the intermediate mechanical resistance value.

[0050] In one embodiment, the processor is configured to select the maximum tip displacement level as the target tip displacement in response to the determined mechanical resistance being less than a first mechanical resistance threshold, to select the minimum tip displacement level as the target tip displacement in response to the determined mechanical resistance being greater than a second mechanical resistance threshold, and to select one of the intermediate tip displacement levels associated with the determined mechanical resistance in response to the determined mechanical resistance being between the first and second mechanical resistance thresholds.

[0051] In one embodiment, at least one of the relationships between the maximum tip displacement level, the minimum tip displacement level, the first mechanical resistance threshold, the second mechanical resistance threshold, or the intermediate tip displacement level is based on user settings.

[0052] In one embodiment, the intermediate tip displacement level is defined by a decreasing curve function that maps a first mechanical resistance threshold to the maximum tip displacement level and a second mechanical resistance threshold to the minimum tip displacement level.

[0053] In one embodiment, the intermediate tip displacement level is defined according to a curve-decrease function based on the voltage corresponding to the puncture of tissue contacted by the tip of the ultrasonic handpiece.

[0054] In one embodiment, the curve reduction function is further based on the resistance offset corresponding to the vibration components of the ultrasonic handpiece.

[0055] In one embodiment, the control console includes a memory for storing multiple tissue response models, each of which is defined based on voltages corresponding to punctures of different tissue types. The processor is configured to receive tissue response models by receiving a user selection of one of the tissue types and retrieving a tissue response model corresponding to the selected tissue type from memory.

[0056] In one embodiment, the intermediate tip displacement level is defined by a negative linear function that maps a first mechanical resistance threshold to the maximum tip displacement level and a second mechanical resistance threshold to the minimum tip displacement level.

[0057] In one embodiment, the target displacement of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the processor is configured to adjust the AC drive signal output by the signal generator to achieve the determined target displacement by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece.

[0058] According to a thirteenth aspect, a control console is provided for controlling the vibration of an ultrasonic handpiece. The control console comprises a signal generator that generates an AC drive signal applied to a transducer of the ultrasonic handpiece, the transducer being coupled to the tip of the ultrasonic handpiece and configured to vibrate the tip of the ultrasonic handpiece in response to the reception of the AC drive signal. The control console further comprises a sensor for measuring the voltage of the AC drive signal, a sensor for measuring the current of the AC drive signal, and a processor coupled to the sensors and the signal generator. The processor is configured to receive a tissue response model that defines a maximum tip displacement level of the tip of the ultrasonic handpiece associated with a first tissue stiffness value, a minimum tip displacement level of the tip of the ultrasonic handpiece associated with a second tissue stiffness value greater than the first tissue stiffness value, and an intermediate tip displacement level of the tip of the ultrasonic handpiece in a range between the maximum tip displacement level and the minimum tip displacement level, wherein the intermediate tip displacement level is associated with an increasing intermediate tissue stiffness value in a range between the first and second tissue stiffness values ​​and decreases as a function of the increasing intermediate tissue stiffness value. The processor is further configured to determine the stiffness value of the tissue in contact with the tip of the ultrasonic handpiece based on the measured current and measured voltage, to determine a target displacement level of the tip based on the determined stiffness value and tissue response model, and to adjust the AC drive signal output by the signal generator to achieve the determined target displacement of the tip.

[0059] According to the 14th aspect, a method for operating the control console of the 13th aspect and / or a method for performing the functions of the control console are provided.

[0060] Any of the above embodiments can be combined in part or in whole. Furthermore, any of the above embodiments can be implemented using any of the following embodiments.

[0061] In one embodiment, an ultrasonic handpiece is coupled to a control console and / or defines a lumen that provides suction to the surgical site.

[0062] Any of the above embodiments can be used in any of the above aspects. Any of the above embodiments can be combined in whole or in part with any one or more aspects described above.

[0063] The merits of this disclosure will be readily apparent, as they will be more readily understood by referring to the following detailed description when considered in relation to the attached drawings. Non-exclusive and non-exclusive examples of this disclosure are described with reference to the following figures, and unless otherwise specified, similar figures throughout the various figures refer to similar parts. [Brief explanation of the drawing]

[0064] [Figure 1] This is a perspective view of an ultrasonic tool system with tissue selection capabilities. [Figure 2] Figure 1 is a schematic diagram of the system components. [Figure 3] This is a circuit diagram modeling the components of an ultrasonic handpiece. [Figure 4] This is a flowchart showing how to perform tissue selection while an ultrasonic handpiece is in operation. [Figure 5] Figure 4 is a flowchart showing additional details of the method. [Figure 6] This is a graph of an tissue response model that includes a linear transition function. [Figure 7] These are graphs of multiple tissue response models, each containing a linear transition function. [Figure 8] This is a graph of a tissue response model that includes a curved transition function. [Figure 9] This is a circuit diagram of components that can contribute to the mechanical resistance of an ultrasonic handpiece. [Modes for carrying out the invention]

[0065] The following description includes numerous specific details to provide a complete understanding of the invention. However, it will be apparent to those skilled in the art that it is not necessary to use these specific details to carry out the invention. In some examples, known materials or methods are not described in detail to avoid obscuring the invention.

[0066] Throughout this specification, any reference to “one case,” “case,” “one example,” or “one example” means that a particular feature, structure, or characteristic described in relation to the case or example is included in at least one case or example of the present invention. Therefore, the appearance of the phrases “in one case,” “in case,” “one example,” or “one example” in various places throughout this specification does not necessarily all refer to the same case or example. Furthermore, a particular feature, structure, or characteristic may be combined in any suitable combination and / or partial combination in one or more cases or examples. In addition, the figures provided with this specification are intended for those skilled in the art and should be understood that the drawings are not necessarily drawn to scale.

[0067] Systems and methods for controlling an ultrasonic handpiece to perform tissue selection are disclosed herein. During a surgical procedure, a surgeon may use an ultrasonic handpiece to contact, cut, and ablate biological tissue. Often, the surgeon intends to cut and / or ablate some types of biological tissue, such as relatively soft tissue, while leaving other types of tissue intact, such as relatively hard (rigid) tissue. For example, a surgeon may use an ultrasonic handpiece to cut and / or ablate a portion of the brain with the intention of cutting and / or ablating softer tissues, such as gray matter and white matter, without cutting and / or ablating stiffer tissues, such as blood vessels, dura mater, arachnoid mater, and pia mater.

[0068] Therefore, this system and method can perform tissue selection to avoid cutting and / or ablation of tissue that the practitioner wishes to keep intact. Specifically, this system and method can control the displacement of the tip of the ultrasonic handpiece based on the stiffness of the tissue in contact with the tip. In response to the tip contact of relatively hard tissue that the practitioner wishes to keep intact, this system and method can reduce the displacement of the tip, thereby making the vibration of the tip insufficient to cut and / or ablate the tissue without excessive force from the practitioner. By controlling the vibration of the tip in this way, the practitioner can operate the ultrasonic handpiece with increased safety and avoid unintended cutting and / or ablation. This system and method also provides improved tactile sensation, which allows the practitioner to better understand contact with different tissue types.

[0069] Figure 1 shows a system 100 for performing tissue selection by controlling the vibration of the tip 102 of an ultrasonic handpiece 104. The ultrasonic handpiece 104 may include a transducer 106 coupled to the tip 102. The transducer 106 may be a stack of piezoelectric drivers located at the proximal end of the ultrasonic handpiece 104. The transducer 106 may be configured to vibrate the tip 102 in response to the reception of an alternating current (AC) drive signal.

[0070] The ultrasonic handpiece 104 can define a lumen 108 extending from the proximal end of the ultrasonic handpiece 104 to the distal end of the tip 102. The lumen 108 can provide suction to the surgical site being treated by the ultrasonic handpiece 104. The ultrasonic handpiece 104 may also include a sleeve 109 positioned to cover and surround the tip 102. The sleeve 109 may be radially spaced away from the tip 102 or longitudinally spaced away from the distal end of the tip 102. During tissue treatment with the ultrasonic handpiece 104, an irrigation fluid can flow through the gap between the tip 102 and the sleeve 109, providing irrigation to the surgical site.

[0071] The ultrasonic handpiece 104 may be a surgical instrument including a cutting accessory (e.g., tip 102) for treating biological tissue. For example, the ultrasonic handpiece 104 may be the ultrasonic surgical handpiece disclosed in U.S. Patent Application No. 16 / 580,639, which, by reference, forms part of this specification in its entirety. As disclosed in U.S. Patent Application No. 16 / 580,639, the tip 102 may have a cutting feature configured for cutting, shaping, and / or removing biological tissue. The tip 102 may have various other features as described in U.S. Patents No. 6,497,715, No. 6,955,680, and No. 6,984,220, which, by reference, also form part of this specification in their entirety.

[0072] The system 100 may include a control console 110, which is coupled to and drives the ultrasonic handpiece 104. The control console 110 may be configured to supply an AC drive signal to the transducer 106 of the ultrasonic handpiece 104. Specifically, referring to Figure 2, the control console 110 may include a signal generator 112 that generates an AC drive signal 114 supplied to the transducer 106 of the ultrasonic handpiece 104. The control console 110 can supply the AC drive signal 114 via a cable 119 (shown in Figure 1) to which the ultrasonic handpiece 104 is connected. The AC drive signal 114 has an AC voltage component v s and AC current component i s This may include: In response to receiving the AC drive signal 114, the transducer 106 controls the voltage v of the AC drive signal 114. s and current i s The tip portion 102 can be vibrated accordingly.

[0073] Referring again to Figure 1, the control console 110 may be configured to generate an AC drive signal 114 based on user input provided to the control console 110 through a foot switch 121 or remote unit 123 coupled to the control console 110. The control console 110 may also include a display 186 that presents information to the practitioner. Non-limiting examples of the information presented may include identification information of the ultrasonic handpiece 104 connected to the control console 110, and the operating status of the system 100. The display 186 may also be a touchscreen display that allows the practitioner to provide user input to the control console 110, such as via on-screen control.

[0074] Referring again to Figure 2, the control console 110 may comprise a processor 122, a memory 124, and a sensor 126. The processor 122 may include one or more devices selected from a microprocessor, a microcontroller, a digital signal processor, a microcomputer, a central processing unit, a field-programmable gate array, a programmable logic device, a state machine, a logic circuit, an analog circuit, a digital circuit, or any other device that operates signals (analog or digital) based on operation instructions stored in the memory 124. The memory 124 may include, but is not limited to, a single memory device or multiple memory devices, including read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, and / or any other device capable of storing information. The memory 124 may also include one or more persistent data storage devices, such as non-volatile solid-state memory, an EPROM, an EEPROM, an RFID tag, or any other device capable of permanently storing information.

[0075] The processor 122 can be configured to implement the functions, features, processes, methods, and modules of the control console 110 as described herein. In particular, the processor 122 may operate under the control of an operating system and / or one or more computer software applications residing in memory 124. When the operating system is run by the processor 122, it can be configured to manage computer resources so that each of the applications can be run by the processor 122. Alternatively, the processor 122 may run the applications directly, in which case the operating system may be omitted.

[0076] Each application and / or operating system may be configured to perform, at runtime, one or more of the functions, features, processes, methods, and modules of the control console 110 described herein. Specifically, each application and / or operating system may be embodied by a set of computer-executable instructions residing in memory 124. Each set of computer-executable instructions, when executed by the processor 122, may be configured to cause the processor 122 to perform one or more of the functions, features, processes, methods, and modules of the control console 110 described herein.

[0077] For example, the processor 122 may be configured to adjust the frequency and amplitude of the AC drive signal 114 generated by the signal generator 112, such as by executing computer executable instructions that embody one or more software applications residing in memory 124, in order to perform tissue selection by the ultrasonic handpiece 104. In particular, the signal generator 112, shown as an AC voltage source in Figure 2, may include a power supply, an amplifier, and a transformer. The ultrasonic handpiece 104 may be coupled to the secondary winding of the transformer. During the operation of system 100, the power supply may output a constant voltage to an amplifier, which may be a variable-gain amplifier. The processor 122 may also be configured to supply control signals to the amplifier. The control signals may set the frequency and amplitude of the voltage generated by the amplifier from the constant voltage. The voltage generated by the amplifier may be applied across the primary winding of the transformer, thereby generating the AC drive signal 114 across the secondary winding. s The frequency of the AC drive signal 114 may be proportional to the voltage applied across the primary winding, and the frequency of the AC drive signal 114 may be equal to the frequency of the applied voltage. Therefore, the processor 122 is configured to set the frequency and voltage of the signal generated by the amplifier, thereby setting the frequency and voltage of the AC drive signal 114 v s It can be configured to set. Exemplary signal generators of this type are disclosed in PCT International Publication 2016 / 183084 and U.S. Patent Application Publication 2018 / 0056328, which together constitute a part of this specification by reference.

[0078] One or more databases that collect and organize data used by the processor 122 when the operating system and / or applications are executed may also reside in memory 124. A database may include data and supporting data structures for storing and organizing the data. A database may be arranged in any database organization or structure, including but not limited to relational databases, hierarchical databases, network databases, or combinations thereof. A database management system in the form of a computer software application executed as instructions on the processor 122 may be used to access information or data stored in database records in response to queries, which may be dynamically determined and executed by the processor 122.

[0079] For example, one or more databases residing in memory 124 may organize tissue data 128. The tissue data 128 may represent one or more tissue response models, which define the target displacement level of the tip 102 of the ultrasonic handpiece 104 as a function of tissue stiffness, or more specifically, as a function of latent tissue stiffness values ​​corresponding to tissues of different stiffness. As will be described in more detail below, the latent tissue stiffness value may be defined by the latent mechanical resistance of the ultrasonic handpiece 104.

[0080] Each tissue response model can be associated with different user settings, which can be provided via the user interface of the control console 110 (e.g., display 168, remote unit 123, foot switch 121), and can indicate one or more tissue types that are desired to be cut and / or ablated, and / or can indicate one or more tissue types for which ablation and / or cutting is desired to be reduced or avoided. The processor 122 can be configured to receive user settings and obtain a tissue response model corresponding to the user settings from the tissue data 128 when the control console 110 is activated. Then, the processor 122 can be configured to control the displacement of the tip 102 based on the obtained tissue response model, cut and / or ablate only the desired tissue types, and / or avoid or reduce the cutting and / or ablation of the undesired tissue types indicated by the user settings.

[0081] The sensor 126 can be configured to measure the voltage v s and current i s of the AC drive signal 114 and communicate these measurements to the processor 122. Although FIG. 2 shows the sensor 126 as a single sensor, the sensor 126 can include any suitable number of sensors that measure the voltage v s and current i s of the AC drive signal 114. The sensor 126 can also include any suitable type of sensor that measures the voltage v s and current i s of the AC drive signal 114. For example, the sensor 126 can include a capacitive or resistive voltage sensor that measures the voltage v s and can include an open-loop or closed-loop current sensor that measures the current i s .

[0082] The ultrasonic handpiece 104 may include a handpiece (HP) memory 130 which may be located within the sleeve 109 of the ultrasonic handpiece 104. The HP memory 130 can store data specific to the ultrasonic handpiece 104 and / or tip 102, such as data identifying the ultrasonic handpiece 104 and / or tip 102, and data defining operating parameters specific to the ultrasonic handpiece 104 and / or tip 102. The HP memory 130 may include one or more of the memory devices described above in relation to the console memory 124, such as an EPROM, EEPROM, or RFID tag.

[0083] When the ultrasonic handpiece 104 is connected to the control console 110, the HP memory 130 may be coupled to the memory reader 132 of the control console 110 in a communicative manner. The memory reader 132 may also be coupled to the processor 122, and may be configured to read data from the HP memory 130 and write data to the HP memory 130 when coupled to the memory reader 132, according to instructions from the processor 122. The structure of the memory reader 132 can complement the HP memory 130. For example, the memory reader 132 may be an assembly capable of reading data from an EPROM or EEPROM, or an assembly capable of interrogating an RFID tag and reading data from it.

[0084] For example, the HP memory 130 may store HP tissue data 133 specific to the ultrasonic handpiece 104 and / or tip 102. The HP tissue data 133 may be similar to the tissue data 128 present in the memory 124 of the control console 110. Specifically, different ultrasonic handpieces 104 and / or tip 102 may respond differently to the reception of the same AC drive signal 114 and affect various tissue types. For example, one type of tip 102 may have cutting features that are effective in cutting a tissue type in response to the ultrasonic handpiece 104 receiving a given AC drive signal 114, while another type of tip 102 may have different cutting features that are relatively less effective in cutting a tissue type in response to the ultrasonic handpiece 104 receiving a given AC drive signal 114. Therefore, the HP tissue data 133 present in the HP memory 130 of the ultrasonic handpiece 104 can define a different tissue response model or set of tissue response models than that defined by the HP tissue data 133 present in the HP memory 130 of another ultrasonic handpiece 104.

[0085] Therefore, in response to the ultrasonic handpiece 104 being connected to the control console 110, the processor 122 may be configured to read HP tissue data 133 specific to the ultrasonic handpiece 104 and / or tip 102 residing in the HP memory 130 via the memory reader 132, and to control the displacement of the tip 102 based on one of the tissue response models defined by the acquired HP tissue data 133, as described above. Alternatively, tissue data 128 residing in the memory 124 of the control console 110 may associate each identifier of a plurality of different ultrasonic handpieces 104 and / or tip 102 with a different tissue response model or a different set of tissue response models. In this case, in response to the ultrasonic handpiece 104 being connected to the control console 110, the processor 122 may be configured to read identification data indicating the identifier of the ultrasonic handpiece 104 and / or tip 102 from the HP memory 130, and to adjust the displacement of the tip 102 using one of the tissue response models associated with the identifier in the tissue data 128.

[0086] Figure 3 shows a circuit modeling the components of the ultrasonic handpiece 104 in operation of system 100. According to this model, the current i of the AC drive signal 114 supplied to the ultrasonic handpiece 104 s It consists of two components, namely the current applied to the transducer 106 of the ultrasonic handpiece 104.

number

[0087] Resistance R of ultrasonic handpiece 104 m (In this specification, "mechanical resistance R m The resistance R (also referred to as "vibration") can be a function of both the vibration components of the ultrasonic handpiece 104 and any material such as biological tissue that is in contact with the vibration components of the ultrasonic handpiece 104 (e.g., the tip 102). Accordingly, when the tip 102 is in contact with tissue, the resistance R m This may include the resistance of the contacting tissue. Tissue resistance may indicate the tissue's stiffness. Therefore, the mechanical resistance R of the ultrasonic handpiece 104... m This can correspond to the rigidity of the tissue in contact with the tip 102 of the ultrasonic handpiece 104. The rigidity of the contacted tissue can be understood to correspond to the elastic modulus of the given tissue, and the mechanical resistance R of the ultrasonic handpiece 104. m The mechanical resistance R can vary as a function of the stiffness of the contacting tissue. Specifically, as the stiffness of the tissue contacted by the tip portion 102 increases, the mechanical resistance R m It can increase. Similarly, as the stiffness of the tissue in contact with the tip 102 decreases, the mechanical resistance R m It can decrease.

[0088] The following relationships related to the example described below can be derived from the circuit in Figure 3 through various circuit analysis techniques.

number

[0089] Figure 4 shows a method 134 for performing tissue selection by adjusting the vibration of the tip 102 of an ultrasonic handpiece 104. In particular, method 134 can cut desired tissue by adjusting the vibration of the tip 102, while avoiding cutting tissue that is desirable to remain intact. Method 134 can also provide improved tactile sensation, which helps the practitioner distinguish between different tissue types being contacted by the tip 102 of the ultrasonic handpiece 104. The processor 122 may be configured to execute method 134 via a set of computer executable instructions, etc., which reside in memory 124 and are configured to cause the processor 122 to execute method 134 when the processor 122 is running. Each step of method 134 is described in more detail below.

[0090] In step 136, the characteristics of the ultrasonic handpiece 104 associated with the tissue in contact with the tip 102, for example, the stiffness value of the tissue in contact, can be measured by the sensor 126 using the voltage v of the AC drive signal 114. s and the current i of the AC drive signal 114 s This can be determined based on the following: As mentioned above, the mechanical resistance R of the ultrasonic handpiece 104 m This can correspond to the rigidity of the tissue contacted by the tip portion 102. Therefore, the mechanical resistance R m This value is determined as the determined stiffness value of the tissue that is in contact with the tip portion 102 and can be used.

[0091] In step 138, the target displacement of the tip 102 can be determined based on the determined characteristics. The displacement of the tip 102 may correspond to the ability of the tip 102 to cut and / or ablate tissue. In particular, given a constant vibration frequency, the ability of the tip 102 to cut and / or ablate tissue can be increased by increasing the displacement of the tip 102 per vibration cycle. Thus, the mechanical resistance R determined in step 136 m However, if the tip 102 corresponds to the tissue that the operator wishes to cut and / or ablate according to the current tissue selection settings, the processor 122 may be configured to select a relatively high target displacement for the tip 102 in order to facilitate tissue cutting. Alternatively, the mechanical resistance R determined in step 136 m However, if the tip 102 corresponds to tissue to which cutting and / or ablation is undesirable according to the current tissue selection settings, the processor 122 may be configured to select a relatively low target displacement for the tip 102 so as to prevent the tip 102 from cutting and / or ablating the tissue.

[0092] For example, the tissue selection setting may indicate that tissue types with stiffness below the stiffness threshold (i.e., relatively soft tissues) will be cut and / or ablated, while tissue types with stiffness above the stiffness threshold (i.e., relatively hard tissues) will be avoided. As described above, the mechanical resistance R of the ultrasonic handpiece 104 m This can indicate the rigidity of the tissue in contact with the tip portion 102. Therefore, the rigidity threshold is the mechanical resistance R m It can be defined in relation to the following: In step 138, the determined mechanical resistance R of the ultrasonic handpiece 104 m The increased mechanical resistance R of the ultrasonic handpiece 104 m In response to this and / or being greater than the stiffness threshold, the processor 122 may be configured to select a reduced target displacement of the tip 102 to avoid cutting and / or ablation of the tissue currently in contact.

[0093] In step 140, the AC drive signal 114 output by the signal generator 112 and supplied to the ultrasonic handpiece 104 can be adjusted to achieve a determined target displacement of the tip 102. In particular, the processor 122 can be configured to generate a control signal that causes the signal generator 112 to generate an AC drive signal 114 that results in a determined target displacement of the tip 102.

[0094] Figure 5 also shows a method 142 for performing tissue selection by adjusting the vibration of the tip 102 of the ultrasonic handpiece 104. The steps of method 142 can be performed in steps 136, 138, and 140 of method 134 shown in Figure 4. Thus, similar to method 134, method 142 can adjust the vibration of the tip 102 to cut and / or ablate desired tissue and avoid cutting and / or ablating tissue that is to be left intact. Method 142 can also provide an improved tactile sensation, which helps the practitioner distinguish between different tissue types being contacted by the tip 102 of the ultrasonic handpiece 104. The processor 122 may be configured to execute method 142 via a set of computer executable instructions, etc., which reside in memory 124 and are configured to cause the processor 122 to execute method 134 when the processor 122 is running.

[0095] Steps 144-152 of Method 142 are performed in step 136 of Method 134, and the tissue stiffness value, more specifically the mechanical resistance R of the ultrasonic handpiece 104, is measured. m This can be determined. In step 144, the capacitance C corresponding to the transducer 106 of the ultrasonic handpiece 104 can be determined. o This can be determined. The capacitance C of transducer 106 o The capacitance C of the transducer 106 can be considered constant during the operation of the ultrasonic handpiece 104. oThe capacitance C of the transducer 106 is measured during the manufacturing of the ultrasonic handpiece 104 and can be stored in HP memory 130. When the ultrasonic handpiece 104 is connected to the control console 110 for surgical procedures, the processor 122 retrieves the capacitance C of the transducer 106 from HP memory 130 via memory reader 132, etc. o It can be configured to read the data.

[0096] In step 146, the resonant frequency of the ultrasonic handpiece 104 can be determined. The processor 122 can be configured to determine the resonant frequency using various methods. For example, the processor 122 may perform a frequency sweep and calculate the mechanical current i using equation (2) above. m The processor 122 may be configured to determine the frequency at which is minimized. Alternatively, the processor 122 may be configured as disclosed in U.S. Patent No. 10, 16, 209, i m against

number

[0097] In step 150, the mechanical current i of the ultrasonic handpiece 104 m This can be calculated. As shown in equation (2), this calculation is the capacitance C of transducer 106. o , the measured voltage v of the AC drive signal 114 s , the measured current i of the AC drive signal 114 s This can be determined based on the frequency of the AC drive signal 114 (for example, the resonant frequency of the ultrasonic handpiece 104).

[0098] In step 152, the mechanical resistance R of the ultrasonic handpiece 104 mThe mechanical current i of the AC drive signal 114 m and the measured voltage v s It can be calculated based on the following. In particular, the mechanical resistance R m The mechanical impedance Z can be calculated using equation (3). m The real part may be equal to the mechanical impedance Z of the ultrasonic handpiece 104 when the ultrasonic handpiece 104 is operating at resonance (i.e., the frequency of the AC drive signal 114 is the resonant frequency of the ultrasonic handpiece 104). m The inactive component, i.e., the inductance L m and capacitance C m These can cancel each other out. As a result, the mechanical impedance Z of the ultrasonic handpiece 104 m The mechanical resistance R of the ultrasonic handpiece 104 is m It can be equal to . In this case, the processor 122 uses the following formula to determine the mechanical resistance R of the ultrasonic handpiece 104. m It can be configured to determine.

number

[0099] In the formula, the voltage v of the AC drive signal 114. s This can be measured by sensor 126, and the mechanical current i m This can be calculated using equation (2). Alternatively, if the ultrasonic handpiece 104 is not operating in resonance (for example, if steps 146 and 148 are omitted), the processor 122 will calculate Z m The mechanical resistance R of the ultrasonic handpiece 104 is calculated by calculating the real part of R. m It can be configured to determine.

[0100] Steps 154 and 156 of Method 142 can be performed to determine the target displacement of the tip 102 in step 138 of Method 134. In step 154, a tissue response model (e.g., tissue response model 166A in Figure 6) can be acquired by a processor 122, etc. The tissue response model may correspond to a potential tissue stiffness value, or more specifically, a potential mechanical resistance R, that can be associated with the tissue in contact with the ultrasonic handpiece 104. m The target displacement of the tip 102 can be defined as a function of . In step 156, the target displacement of the tip 102 can be determined based on the tissue response model and a previously determined stiffness value corresponding to the stiffness of the contacted tissue.

[0101] Step 158 of Method 142 can be performed to adjust the AC drive signal 114 in step 140 of Method 134 to achieve the determined target displacement of the tip 102. The displacement level of the tip 102 during the vibration cycle is controlled by the mechanical current i of the ultrasonic handpiece 104. m It can be proportional to the mechanical current i. m As the mechanical current i increases, the displacement of the tip portion 102 changes. m It can increase in proportion to the increase of the mechanical current i m When the mechanical current i decreases, the displacement of the tip portion 102 changes. m It can be reduced in proportion to the decrease in the target mechanical current i of the ultrasonic handpiece 104. Therefore, the target displacement of the tip portion 102 is proportional to the target mechanical current i of the ultrasonic handpiece 104. m_target This can correspond to the actual mechanical current i of the ultrasonic handpiece 104 in step 158. m However, the target mechanical current i corresponding to the target displacement m_target To be substantially equal to (for example, target mechanical current i m_target Target mechanical current i within 20 milliamperes, 10 milliamperes, or 2 milliamperes m_target Within 1 milliampere, target mechanical current i m_target It can be adjusted by 10%, 5%, or 1%.

[0102] Specifically, in response to determining the target displacement of the tip 102, the processor 122 adjusts the AC drive signal 114 such that the actual mechanical current i m becomes substantially equal to the target mechanical current i m_Target corresponding to the target displacement. For example, the processor 122 may perform an iterative process, such as using a PID control loop, to make the actual mechanical current i m calculated using Equation (2) substantially equal to the target mechanical current i m_Target by generating a voltage v s of the AC drive signal 114.

[0103] FIGS. 6-8 show various exemplary tissue response models 166 that can be used by the processor 122 to determine the target displacement of the tip 102 based on the determined tissue stiffness value, or more specifically, based on the mechanical resistance R m of the ultrasonic handpiece 104. The illustrated tissue response models 166 are intended to be non-limiting, as other tissue response models that define the target displacement of the tip 102 as a function of the tissue stiffness value may be suitable.

[0104] Each tissue response model 166 can be represented by a graph where the y-axis represents the target displacement and the x-axis represents the potential tissue stiffness value. The illustrated tissue response models 166 define the tissue stiffness value with respect to the mechanical resistance R m of the ultrasonic handpiece 104 and define the target displacement with respect to the target mechanical current i m_Target .

[0105] In other examples, the tissue response model may represent the target displacement with respect to the amplitude of the displacement of the tip 102 during the vibration cycle, and / or may represent the tissue stiffness value with respect to another characteristic derivable from the voltage v s and current i s of the AC drive signal 114. For example, the tissue response model may represent the target displacement in micrometers. In this case, the processor 122 may, for example, via a look-up table, convert the determined target displacement of the tip 102 to the target mechanical current i corresponding to the determined target displacementm_Target may be configured to convert to. Then, the processor 122 may be configured to implement the target displacement by generating a control signal to the signal generator 112 that causes the measured mechanical current i of the ultrasonic handpiece 104 to be equal to the determined target mechanical current i m m_Target Another example, the tissue response model may represent a tissue stiffness value with respect to the impedance of the ultrasonic handpiece 104 that may be determined by dividing the measured voltage v of the AC drive signal 114 by the measured current i of the AC drive signal 114 s s

[0106] Referring to FIG. 6 as an example, each tissue response model 166 may define a maximum tip displacement level 176, a minimum tip displacement level 178 less than the maximum tip displacement level 176, and a plurality of intermediate tip displacement levels extending between the maximum tip displacement level 176 and the minimum tip displacement level 178. The maximum tip displacement level 176 of each tissue response model 166 may be associated with a potential tissue stiffness value below a lower stiffness threshold 182 represented by a lower mechanical resistance threshold, and the minimum tip displacement level 178 of each tissue response model 166 may be associated with a potential tissue stiffness value above an upper stiffness threshold 184 represented by an upper mechanical resistance threshold

[0107] The intermediate tip displacement levels of each tissue response model 166 may be associated with intermediate potential tissue stiffness values, and the intermediate potential tissue stiffness values may extend between a lower stiffness threshold 182 and an upper stiffness threshold 184 according to a transition function 167, and may be represented by an intermediate potential mechanical resistance R value. In particular, each intermediate tip displacement level may be based on the application of different intermediate tissue stiffness values to the transition function 167, and thus may be associated with different potential intermediate tissue stiffness values within the tissue response model 166. Therefore, the relationship between the intermediate tip displacement level and the intermediate potential stiffness value can be defined by the transition function 167. The transition function 167 increases as the intermediate potential tissue stiffness value increases (e.g., mechanical resistance R m m ​​​​It can be a decreasing function that decreases from a maximum tip displacement level of 176 to a minimum tip displacement level of 178 over a range where the value increases.

[0108] In step 156 of method 142, the processor 122 measures the mechanical resistance R of the ultrasonic handpiece 104. m The system can be configured to determine the target displacement of the tip portion 102 based on the acquired tissue response model 166 by determining whether the mechanical resistance R is below the lower stiffness threshold 182, above the upper stiffness threshold 184, or between the lower stiffness threshold 182 and the upper stiffness threshold 184. m In response that the lower stiffness threshold R is less than 182, the processor 122 can select the maximum tip displacement level 176 as the target displacement level. m In response to the upper stiffness threshold being 184 or higher, the processor 122 can select the minimum tip displacement level 178 as the target displacement level. Mechanical resistance R m In response to the fact that the value is between the lower stiffness threshold 182 and the upper stiffness threshold 184, the processor 122 sets the target displacement level of the tip portion 102 according to the transition function 167, based on the mechanical resistance R m This can be set as the intermediate tip displacement level associated with it.

[0109] For example, referring to the tissue response model 166A in Figure 6, the processor 122 determines the mechanical resistance R m In response to the fact that is 1000Ω or less, the target displacement may be set to 50 milliamperes (mA). The processor 122 then determines the mechanical resistance R m In response to the fact that is 10000Ω or more, the target displacement may be set to 5mA. The processor 122 determines the mechanical resistance R m In response to the value being 1000Ω to 10000Ω, the target displacement may be set to 50mA to 5mA. For example, the processor 122 determines the mechanical resistance R m In response to the resistance being 5000Ω, a target displacement of 30mA may be set.

[0110] The maximum tip displacement level 176 for each tissue response model 166 may correspond to the maximum allowable displacement level of the tip 102 of the operating ultrasonic handpiece 104. This level may be set by the user, for example, using the display 186 on the control console 110. In particular, memory 124 and / or HP memory 130 may contain data defining the global maximum displacement level of the ultrasonic handpiece 104. Prior to the operation of the ultrasonic handpiece 104, the user may input into the control console 110 an input that defines a percentage of the global maximum displacement level to be used as the maximum tip displacement level 176. Such user input may be referred to as the "power level". Based on the power level provided by the user, the processor 122 may be configured to set the maximum tip displacement level 176 to a percentage of the global maximum displacement level corresponding to the power level. Referring to Figure 6, for example, the global maximum displacement level of the ultrasonic handpiece 104 may be 100 mA, and the user-supplied power level may be 50 percent, so that the processor 122 sets the maximum tip displacement level 176 to 50 mA.

[0111] The processor 122 determines the rigidity of the tissue contacted by the tip 102, which is determined by the tissue rigidity value, or more specifically, the mechanical resistance R of the ultrasonic handpiece 104. m When the lower limit stiffness threshold is 182 or less, the tip 102 can be configured to operate at the maximum tip displacement level 176. The maximum tip displacement level 176 occurs when the tip 102 of the ultrasonic handpiece 104 makes contact with the mechanical resistance R of the ultrasonic handpiece 104. m This may be sufficient to cut and / or ablate tissue types whose lower stiffness threshold is 182 or less. In other words, the processor 122 controls the mechanical resistance R of the ultrasonic handpiece 104. m For each contacted tissue type having stiffness that keeps the lower limit stiffness threshold below 182, the tip 102 may be configured to vibrate at the same tip displacement level, i.e., the maximum tip displacement level of 176.

[0112] The tip 102 of the ultrasonic handpiece 104 reacts to the determined tissue stiffness value, or more specifically, the mechanical resistance R m In response to contact with tissue having a stiffness greater than the lower stiffness threshold 182, the processor 122 may be configured to reduce the displacement of the tip 102 according to the transition function 167, thereby reducing the effect of the tip 102 when cutting and / or ablating the contacted tissue. The operator may feel vibration and reduced effect of the tip 102, which can be interpreted as an indicator that the tip 102 is in contact with or approaching tissue that should not be cut and / or ablated. In response, the operator can withdraw the ultrasonic handpiece 104 from the tissue. Thus, the lower stiffness threshold 182 of each tissue response model 166 may define tissue types that are desirable to cut and / or ablate (e.g., tissues with stiffness values ​​less than or equal to the lower stiffness threshold 182), or it may define tissue types that should remain intact (e.g., tissues with stiffness values ​​greater than the lower stiffness threshold 182).

[0113] In some examples, the processor 122 may be configured to determine a lower stiffness threshold 182 for each tissue response model 166 based on user inputs, such as the user input power level described above. For example, for each tissue response model 166 available to the processor 122 for controlling the displacement of the tip 102, the tissue data 128 and / or HP tissue data 133 may define the transition function 167, the minimum tip displacement level 178, and the upper stiffness threshold 184 such that the transition function 167 intersects with the minimum tip displacement level 178 at the upper stiffness threshold 184. In response to obtaining the tissue response model 166 from the tissue data 128 or HP tissue data 133, the processor 122 may be configured to determine the intersection of the transition function 167 and the user-defined maximum tip displacement level 176 as the lower stiffness threshold 182 for the tissue response model 166.

[0114] The minimum tip displacement level 178 of each tissue response model 166 may correspond to a non-zero minimum tip displacement level of the tip 102, and advantageously, the stiffness of the contacting tissue is relatively high, i.e., the mechanical resistance R is greater than or equal to the upper stiffness threshold 184, which may also be referred to herein as the stall threshold. m If this is indicated, it may be possible for the ultrasonic handpiece 104 to enter a non-zero “stall mode.” This may occur if the tip 102 comes into contact with relatively stiff tissue that is undesirable to be cut and / or ablated, or if the operator continues to press the tip 102 into stiff tissue that is undesirable to be cut and / or ablated. During stall mode, the target displacement of the tip 102 may be set to a minimum tip displacement level 178 (e.g., 5 mA), which may be insufficient to cut and / or ablate the contacted tissue.

[0115] By setting the minimum tip displacement level 178 to a non-zero value, the processor 122 can continuously track the resonant frequency of the ultrasonic handpiece 104 and, accordingly, maintain the operation of the ultrasonic handpiece 104 in a resonant state during stall mode. Such a configuration is advantageous when the tip 102 transitions from contact with more rigid tissue that is undesirable to be cut and / or ablated to contact with softer, more rigid tissue that is desirable to be cut and / or ablated. By maintaining the operation of the ultrasonic handpiece 104 in a resonant state during stall mode, the processor 122 can continuously monitor the tissue that the tip 102 is in contact with and determine the timing of the transition of the tip 102 to such soft tissue. In response to this transition, the processor 122 may be configured to adjust the AC drive signal 114 output by the signal generator 112 so that the displacement of the tip 102 caused by the adjusted AC drive signal 114 is the maintained resonant frequency of the ultrasonic handpiece 104, allowing the tissue in contact with the tip 102 to be cut and / or ablated (e.g., at the maximum tip displacement level 176). The processor 122 can perform this adjustment without first establishing resonance, and as a result, can switch back to a tip displacement level 102 sufficient to cut and / or ablate the tissue relatively quickly.

[0116] Specifically, if the processor 122 stops the displacement of the tip 102 in stall mode rather than placing the tip 102 at a non-zero displacement level, the processor 122 may need to be configured to periodically or as needed restart the ultrasonic handpiece 104 to check for a transition to softer, stiffer tissue that is desirable to be cut and / or ablated. When the ultrasonic handpiece 104 is restarted, the processor 122 needs to dedicate processing time to determining the frequency of the AC drive signal 114 and setting it to the resonant frequency, which may result in a relatively irregular and slow transition back to the maximum tip displacement level 176. Therefore, a non-zero stall mode allows the processor 122 to transition the tip 102 from the minimum tip displacement level 178 to the maximum tip displacement level 176 relatively smoothly and quickly.

[0117] The transition function 167 for each tissue response model 166 can be understood as defining the sensitivity of the tissue response model 166. In particular, the transition function 167 may be a decreasing function that extends from the maximum tip displacement level 176 to the minimum tip displacement level 178. The faster the rate at which the transition function 167 decreases from the maximum tip displacement level 176 to the minimum tip displacement level 178 over the range of stiffness values, the faster the processor 122 can be configured to place the ultrasonic handpiece 104 into stall mode after the tip 102 has contacted tissue that should be avoided, and accordingly, the sensitivity of the tissue response model 166 will be higher.

[0118] As shown in Figures 6 and 7, one or more transition functions 167 of the stored tissue response models 166 are:

number

number

[0119] The transition functions 167 for each tissue response model 166 may provide advantages to the user of the ultrasonic handpiece 104 by providing the user with gradually increasing tactile feedback as the tip 102 comes into contact with tissue of increasing stiffness. In particular, the force applied to the ultrasonic handpiece 104 when the tip 102 is vibrating against the tissue increases as the tip displacement decreases and the tissue stiffness increases. According to the transition function 167, as the stiffness of the tissue in contact with the tip 102 increases from the lower stiffness threshold 182 to the upper stiffness threshold 184, the displacement of the tip 102 may decrease from the maximum tip displacement level 176 to the minimum tip displacement level 178. Correspondingly, as the tip 102 vibrates against stiffer tissue, the force applied to the ultrasonic handpiece 104 and felt by the user may gradually increase. This may serve to provide the user with feedback that the tip 102 is in contact with stiffer tissue that is undesirable to be cut and / or ablated.

[0120] This configuration allows the user to perceive the stiffness of the tissue being contacted by the tip 102, and to indicate to the user when the tip 102 is in contact with, or nearly in contact with, the tissue intended to be avoided, before the ultrasonic handpiece 104 enters stall mode. Specifically, the tip 102 first detects the mechanical resistance R near the lower stiffness threshold 182. m When contact is made with tissue having the corresponding rigidity, the practitioner can continue to press the tip 102 against this tissue. As the practitioner continues to press the tip 102 against the tissue, the mechanical resistance R of the ultrasonic handpiece 104 increases. m This can increase toward the upper stiffness threshold 184. By decreasing the displacement of the tip 102 according to the transition function 167, the tactile feedback provided increases, allowing the practitioner to perceive the mechanical resistance R of the ultrasonic handpiece 104. m Before reaching the upper stiffness threshold 184, it may be possible to detect contact with harder tissue and retract the tip 102 from the tissue accordingly. As a result, the practitioner can avoid entering stall mode and avoid tissue damage that may occur if the practitioner continues to apply excessive force to the ultrasonic handpiece 104, causing the tip 102 to penetrate the tissue.

[0121] As described above, the tissue data 128 and HP tissue data 133 can each define multiple tissue response models 166, each containing different tissue selectivity settings (e.g., different lower stiffness thresholds 182) and / or different sensitivity settings (e.g., different transition functions 167). Therefore, the processor 122 may be configured to select one of these tissue response models 166 to adjust the ultrasonic handpiece 104 based on user input defining tissue selectivity and / or sensitivity. Specifically, prior to the operation of the ultrasonic handpiece 104, the user can input such input to the control console 110 via a display 186, etc. In response to the control console 110 receiving user input, the processor 122 may be configured to acquire the tissue response model 166 corresponding to the user input.

[0122] For example, Figure 7 shows tissue response models 166A to 166E, which may be defined by tissue data 128 or HP tissue data 133. Each tissue response model 166A to 166E may have the same tissue sensitivity, as indicated by the similar slope and length of their respective transition functions 167. However, the lower stiffness thresholds 182 of each tissue response model 166A to 166E are different, indicating that the tissue response models 166A to 166E have different tissue selectivity.

[0123] In particular, tissue response model 166A can be configured to avoid cutting softer tissue than tissue response model 166B, tissue response model 166B can be configured to avoid cutting softer tissue than tissue response model 166C, and so on. More specifically, the lower stiffness threshold 182A of tissue response model 166A is less than the lower stiffness threshold 182B of tissue response model 166B. Therefore, when the tip 102 comes into contact with tissue with increased stiffness, tissue response model 166A reduces the displacement of the tip 102 to the processor 122 before tissue response model 166B reduces the displacement of the tip 102 to the processor 122. Thus, tissue response model 166A can avoid cutting and / or ablating softer tissue than tissue response model 166B. Therefore, in response to receiving user input indicating a tissue selectivity setting that corresponds to avoiding all tissues except the softest tissue, the processor 122 can be configured to acquire and implement tissue response model 166A. Alternatively, in response to receiving user input indicating a tissue selectivity setting that corresponds to avoiding only the toughest tissue, the processor 122 can be configured to acquire and implement a tissue response model 167E.

[0124] As described above, the relationship between one or more intermediate tip displacement levels and intermediate potential stiffness values ​​among the tissue response models 166 can be defined by a decrease curve function. Each of these decrease curve functions of the tissue response models 166 can be configured to prevent puncture of one or more different tissue types. Before operating the ultrasound handpiece 104, the operator can provide a user selection of tissue types to avoid puncture, ablation, and / or cutting. In response to receiving such input, the processor 122 may be configured to acquire the tissue response model 166 corresponding to the selected tissue type and adjust the displacement level of the tip 102 based on the tissue response model 166 to avoid or reduce puncture of the indicated tissue type.

[0125] As an example, Figure 8 shows a tissue response model 166F in which the intermediate tip displacement level is defined by a curve transition function 167F for preventing puncture of a particular tissue type. In particular, Figure 8 shows a tissue puncture curve 188 corresponding to a combination of displacement level and stiffness value in which puncture of a particular tissue type may occur. For example, the tissue puncture curve 188 is in which the mechanical current i m The current is 20mA, and the mechanical resistance R of the ultrasonic handpiece 104 is m This indicates that the ultrasonic handpiece 104 can puncture a specific tissue type when the impedance is 7500Ω. The tissue puncture curve 188 for a specific tissue type may be determined empirically, as will be described in more detail below. The curve transition function 167F of the tissue response model 166F is obtained from the tissue puncture curve 188 with a safety margin i safety This can be determined by subtracting, thereby preventing or reducing punctures of specific tissue types associated with the tissue response model 166F during the operation of the ultrasound handpiece 104 by the tissue response model 166F.

[0126] As described above, the tissue puncture curve 188 for a particular tissue type can be determined empirically. In particular, the tissue puncture curve 188 can be determined by operating the ultrasound handpiece 104 on this tissue type and determining the average force (referred to herein as the "force limit") required to puncture this tissue. The tissue puncture curve 188 can then be calculated using the following formula.

number

[0127] The force limit for a given tissue type is the puncture voltage v corresponding to the puncture of that tissue type. Tissue This can be represented by the following. Referring to Figure 9, during normal operation of the ultrasonic handpiece 104, the mechanical resistance R of the ultrasonic handpiece 104 m The puncture voltage v corresponding to puncturing the tissue type Tissue To determine this, the ultrasonic handpiece 104 can be applied to tissue types under various power level settings without one or more of these additional resistive components such as the sleeve 109, irrigation, and aspiration. Immediately before puncturing the tissue type at each power level setting, the voltage v of the AC drive signal 114 supplied to the ultrasonic handpiece 104 s The measured voltages v may also be measured, and these measured voltages v s The average of R in equation (5) may be used as the force limit. offset This includes the vibration components of the ultrasonic handpiece 104, and the mechanical resistance R of the ultrasonic handpiece 104. m The resistance offset may correspond to components other than tissue that contribute to the effect, and when the tip 102 is vibrating in water or air and not pressed against tissue, the mechanical resistance R of the ultrasonic handpiece 104 is as described above. mThis may be determined by calculating [the value].

[0128] The above procedure can be used to generate a tissue puncture curve 188 and, correspondingly, a curve transition function 167F, thereby reducing the displacement of the tip 102 to prevent or reduce tissue puncture, cutting, and / or ablation, while minimizing mechanical resistance R m It is not excessively reduced due to other contributing components, etc. As shown in Figure 8, the tissue puncture curve 188 and the curve transition function 167F are curve reduction functions, respectively. Since the force limit in equation (5) is considered to be a constant value for each tissue type, the mechanical resistance R of the ultrasonic handpiece 104 m As increases, the output of equation (5), and correspondingly, the safety margin i from the output of equation (5) safety The curve transition function 167F, which can be equal to the one obtained by subtracting the value of 167F, decreases.

[0129] This specification describes systems and methods for performing tissue selection during the operation of an ultrasonic handpiece to avoid cutting tissue types that should be left intact. Specifically, these systems and methods can avoid undesirable tissue cutting by controlling the displacement of the tip of the ultrasonic handpiece based on the rigidity of the tissue in contact with the tip. By controlling the ultrasonic handpiece in this way, the operator can operate the ultrasonic handpiece with increased safety and avoid unintended cutting. These systems and methods also provide improved tactile feedback and enable the operator to better understand contact with different tissue types.

[0130] The specific features of various examples in this disclosure may be shown in some drawings and not in others, but this is simply for convenience. In accordance with the principles of this disclosure, any feature of a drawing or other example may be referenced and / or claimed in combination with any feature of any other drawing or example.

[0131] This description uses examples to illustrate the cases of the Disclosure and enable any person skilled in the art to implement the cases, such as creating and using any device or system and implementing any incorporated method. The patentable scope of the Disclosure is defined by the claims and may include other examples that a person skilled in the art may conceive. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the literal wording of the claims, or if they include structural elements that are equivalent to the literal wording of the claims with only slight differences. Furthermore, in order to maintain the disclosures made at the time of filing this application, the contents of claims 1 to 74 at the time of filing this application are added below. (Claim 1) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises a signal generator that generates the AC drive signal applied to the transducer, a sensor that measures the voltage of the AC drive signal, a sensor that measures the current of the AC drive signal, and a processor coupled to the sensor and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Determining a first displacement level of the tip, which is the maximum displacement level of the tip, Receiving the tissue response model which defines a stiffness threshold and a second displacement level of the tip that is associated with different potential tissue stiffness values, each of which is smaller than the first displacement level and larger than the stiffness threshold in the tissue response model, Based on the measured voltage and current of the AC drive signal, the tissue stiffness value of the tissue contacted by the tip is determined. To determine whether the determined tissue stiffness value is less than the stiffness threshold, In response to the determination that the determined tissue stiffness value is less than the stiffness threshold, the target displacement level of the tip is set to the first displacement level. In response to the determination that the determined tissue stiffness value is greater than the stiffness threshold, the target displacement level of the tip is set to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value. The AC drive signal output to the ultrasonic handpiece by the signal generator is adjusted to achieve the set target displacement level. A system configured to control the vibration of the tip of an ultrasonic handpiece. (Claim 2) The system according to claim 1, wherein the processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal as the determined tissue stiffness value, the stiffness threshold is defined by the mechanical resistance threshold, and the potential tissue stiffness value is defined by the potential mechanical resistance of the ultrasonic handpiece. (Claim 3) The aforementioned processor, Determining the capacitance of the transducer of the ultrasonic handpiece, Determining the resonant frequency of the ultrasonic handpiece, The frequency of the AC drive signal is set to the determined resonant frequency of the ultrasonic handpiece, Based on the capacitance of the transducer, the frequency of the AC drive signal, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, the current flowing through the mechanical components of the ultrasonic handpiece is calculated. The mechanical resistance of the ultrasonic handpiece is calculated based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal. The system according to claim 2, configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal. (Claim 4) The system according to any one of claims 1 to 3, wherein the tissue response model defines the second displacement level such that the second displacement level decreases as the potential tissue stiffness value increases. (Claim 5) The stiffness threshold is a first stiffness threshold, the tissue response model defines a third displacement level of the tip, which is the minimum non-zero tip displacement level of the tip and is less than the second displacement level, and defines a second stiffness threshold greater than the potential tissue stiffness value, and the processor, In response to the determined tissue stiffness value being greater than the second stiffness threshold, the target displacement level of the tip is set to the third displacement level. In response to the determined tissue stiffness value being greater than the first stiffness threshold and less than the second stiffness threshold, the target displacement level of the tip is set to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value. A system according to any one of claims 1 to 4, configured to perform the following: (Claim 6) The system according to claim 5, wherein at least one of the first displacement level, the second displacement level, the third displacement level, the first stiffness threshold, the second stiffness threshold, or the relationship between the second displacement level and the potential structural stiffness value is based on user settings. (Claim 7) The system according to claim 5 or 6, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a negative linear function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level. (Claim 8) The system according to claim 5 or 6, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a decreasing curve function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level. (Claim 9) The system according to any one of claims 1 to 6 and 8, wherein the tissue response model is configured to reduce tissue ablation during the operation of the ultrasonic handpiece, and the relationship between the second displacement level and the potential tissue stiffness value is defined by a curve-declining function based on the voltage of the AC drive signal corresponding to the puncture of the tissue. (Claim 10) The system according to claim 9, wherein the curve reduction function is further based on the resistance offset corresponding to the vibration component of the ultrasonic handpiece. (Claim 11) The aforementioned tissue response model is the first tissue response model, The system further includes a memory for storing the first tissue response model and a second tissue response model configured to ablate tissue that is harder than the first tissue response model. The aforementioned processor, Receiving user selections of the first organizational response model and the second organizational response model via the user interface, In response to the user selection of the first tissue response model, the target displacement level is set to the first displacement level in response to the tip being positioned relative to a first tissue type, and in response to the tip being positioned relative to a second tissue type that is harder than the first tissue type, the target displacement level is set to a displacement level less than the first displacement level. In response to the user selection of the second tissue response model, and in response to the fact that the tip is positioned relative to the first tissue type and the second tissue type, the target displacement level is set to the first displacement level. A system according to any one of claims 1 to 10, configured to perform the following: (Claim 12) The system according to claim 11, wherein the stiffness threshold is a first stiffness threshold, the latent tissue stiffness value is a first latent tissue stiffness value, the second tissue response model defines a second stiffness threshold greater than the first stiffness threshold, each of the second displacement levels is associated with a different second latent tissue stiffness value greater than the second stiffness threshold, and at least one of the first latent tissue stiffness values ​​is less than each of the second latent tissue stiffness values. (Claim 13) The system according to claim 11 or 12, wherein the relationship between the second displacement level and the second potential tissue stiffness value is defined by a function based on the voltage of the AC drive signal corresponding to puncture of a third tissue type that is stiffer than the second tissue type. (Claim 14) The system according to any one of claims 1 to 13, wherein the target displacement level of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the processor is configured to adjust the AC drive signal output by the signal generator to achieve the set target displacement level by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece. (Claim 15) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises a signal generator that generates the AC drive signal applied to the transducer, and a processor coupled to the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Activating stall mode when the displacement of the tip of the ultrasonic handpiece caused by the ultrasonic handpiece is non-zero and insufficient to ablate the tissue in contact with the tip, While the stall mode is active, the resonant frequency of the ultrasonic handpiece is maintained. A system configured to control the vibration of the tip of an ultrasonic handpiece. (Claim 16) The aforementioned processor, Receiving user input indicating the type of tissue that should remain intact, The stall mode is activated in response to the tip being positioned relative to the tissue type during the vibration of the tip by the control console. The system according to claim 15, configured to perform the following: (Claim 17) The control console is A sensor for measuring the voltage of the AC drive signal, A sensor that measures the current of the AC drive signal and Furthermore, The aforementioned processor, Based on the measured voltage and current of the AC drive signal, the tissue stiffness value is determined. To determine whether the aforementioned tissue stiffness value is greater than the stiffness threshold, In response to the determination that the tissue stiffness value is greater than the stiffness threshold, the stall mode is activated. The system according to claim 15 or 16, configured to perform the following: (Claim 18) The system according to claim 17, wherein the stiffness threshold is defined by a mechanical resistance threshold, and the processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal as the tissue stiffness value. (Claim 19) The aforementioned processor, The second mechanical resistance of the ultrasonic handpiece is determined based on the second voltage and current of the AC drive signal measured by the sensor when the stall mode is active. Determining whether the second mechanical resistance is less than the stiffness threshold, In response to determining that the second mechanical resistance is below the stiffness threshold, the stall mode is deactivated, the AC drive signal output by the signal generator is adjusted so that the displacement of the tip caused by the adjusted AC drive signal is at the maintained resonant frequency and can ablate the tissue in contact with the tip. The system according to claim 18, configured to perform the following: (Claim 20) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises: a signal generator that generates the AC drive signal applied to the transducer; a sensor that measures the voltage of the AC drive signal; a sensor that measures the current of the AC drive signal; and a processor coupled to the sensor and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Based on the measured voltage and measured current of the AC drive signal, the characteristics of the ultrasonic handpiece associated with the tissue contacted by the tip are determined. Based on the determined characteristics and the puncture voltage corresponding to the tissue contacted by the tip, the target displacement of the tip is determined. The AC drive signal output by the signal generator is adjusted to achieve the determined target displacement of the tip. A system configured to perform the following actions. (Claim 21) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises: a signal generator that generates the AC drive signal applied to the transducer; a sensor that measures the voltage of the AC drive signal; a sensor that measures the current of the AC drive signal; a memory that stores a first tissue response model and a second tissue response model configured to ablate tissue harder than the first tissue response model; and a processor coupled to the sensor, the memory, and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Determining a first displacement level of the tip, which is the maximum displacement level of the tip, Receiving user selections of the first organizational response model and the second organizational response model via the user interface, In response to the user selection of the first tissue response model, the target displacement level of the tip is set to the first displacement level in response to the tip being positioned relative to a first tissue type, and in response to the tip being positioned relative to a second tissue type that is harder than the first tissue type, the target displacement level is set to a second displacement level that is less than the first displacement level. In response to the user selection of the second tissue response model and in response to the fact that the tip is positioned relative to the first tissue type and the second tissue type, the target displacement level is set to the first displacement level. The AC drive signal output by the signal generator is adjusted to achieve the set target displacement level of the tip. A system configured to perform the following actions. (Claim 22) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, The steps include supplying the AC drive signal to the ultrasonic handpiece, The steps include measuring the voltage and current of the AC drive signal, A step of determining a first displacement level of the tip, which is the maximum displacement level of the tip; The steps include receiving a tissue response model that defines a stiffness threshold and a second displacement level of the tip, each associated with different potential tissue stiffness values ​​that are smaller than the first displacement level and larger than the stiffness threshold in the tissue response model, The steps include determining the tissue stiffness value of the tissue contacted by the tip based on the measured voltage and current of the AC drive signal, The steps include determining whether the determined tissue stiffness value is less than the stiffness threshold, In response to the determination that the determined tissue stiffness value is less than the stiffness threshold, the step of setting the target displacement level of the tip portion to the first displacement level, In response to the determination that the determined tissue stiffness value is greater than the stiffness threshold, the step of setting the target displacement level of the tip portion to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value, The steps of adjusting the AC drive signal supplied to the ultrasonic handpiece to achieve the set target displacement level, A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above. (Claim 23) The step of determining the tissue stiffness value of the tissue contacted by the tip based on the measured voltage and current of the AC drive signal is as follows: Based on the measured voltage and current of the AC drive signal, the mechanical resistance of the ultrasonic handpiece is determined. The mechanical resistance is used as the determined structural stiffness value. The method according to claim 22, which includes the following: (Claim 24) Determining the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal is: Determine the capacitance of the transducer of the ultrasonic handpiece. The resonant frequency of the ultrasonic handpiece is determined, The frequency of the AC drive signal is set to the determined resonant frequency of the ultrasonic handpiece. Based on the capacitance of the transducer, the frequency of the AC drive signal, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, the current flowing through the mechanical components of the ultrasonic handpiece is calculated. The mechanical resistance of the ultrasonic handpiece is calculated based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal. The method according to claim 23, including the act of (Claim 25) The method according to any one of claims 22 to 24, wherein the tissue response model defines the second displacement level such that the second displacement level decreases as the potential tissue stiffness value increases. (Claim 26) The stiffness threshold is a first stiffness threshold, the tissue response model defines a third displacement level of the tip, which is the minimum non-zero tip displacement level of the tip and is less than the second displacement level, and the tissue response model defines a second stiffness threshold that is greater than the potential tissue stiffness value. In response to the determined tissue stiffness value being greater than the second stiffness threshold, the step of setting the target displacement level of the tip to the third displacement level, In response to the determined tissue stiffness value being greater than the first stiffness threshold and less than the second stiffness threshold, the step of setting the target displacement level of the tip to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value. The method according to any one of claims 22 to 25, further comprising: (Claim 27) The method according to claim 26, wherein at least one of the first displacement level, the second displacement level, the third displacement level, the first stiffness threshold, the second stiffness threshold, or the relationship between the second displacement level and the potential structural stiffness value is based on a user setting. (Claim 28) The method according to claim 26 or 27, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a negative linear function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level. (Claim 29) The method according to claim 26 or 27, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a decreasing curve function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level. (Claim 30) The method according to any one of claims 22 to 27 and 29, wherein the tissue response model is configured to reduce tissue ablation during the operation of the ultrasonic handpiece, and the relationship between the second displacement level and the potential tissue stiffness value is defined by a curve-declining function based on the voltage of the AC drive signal corresponding to the puncture of the tissue. (Claim 31) The method according to claim 30, wherein the curve reduction function is further based on the resistance offset corresponding to the vibration component of the ultrasonic handpiece. (Claim 32) The aforementioned tissue response model is the first tissue response model, The steps include receiving user selections of a first tissue response model and a second tissue response model via a user interface, wherein the second tissue response model is configured to ablate tissue that is stiffer than the first tissue response model; The steps include: setting the target displacement level to the first displacement level in response to the user selection of the first tissue response model and in response to the tip being positioned relative to a first tissue type, and setting the target displacement level to a displacement level less than the first displacement level in response to the tip being positioned relative to a second tissue type that is harder than the first tissue type; The steps of setting the target displacement level to the first displacement level in response to the user selection of the second tissue response model and in response to the fact that the tip is positioned relative to the first tissue type and the second tissue type, The method according to any one of claims 22 to 31, further comprising: (Claim 33) The method according to claim 32, wherein the stiffness threshold is a first stiffness threshold, the latent tissue stiffness value is a first latent tissue stiffness value, the second tissue response model defines a second stiffness threshold greater than the first stiffness threshold, associates each of the second displacement levels with a different second latent tissue stiffness value greater than the second stiffness threshold, and at least one of the first latent tissue stiffness values ​​is less than each of the second latent tissue stiffness values. (Claim 34) The method according to claim 32 or 33, wherein the relationship between the second displacement level and the second potential tissue stiffness value is defined by a function based on the voltage of the AC drive signal corresponding to puncture of a third tissue type that is stiffer than the second tissue type. (Claim 35) The method according to any one of claims 22 to 34, wherein the target displacement level of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the method further comprises the step of adjusting the AC drive signal supplied to the ultrasonic handpiece to achieve the set target displacement level by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece. (Claim 36) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, The steps include supplying the AC drive signal to the ultrasonic handpiece, The steps include activating a stall mode, wherein the displacement of the tip of the ultrasonic handpiece caused by the ultrasonic handpiece is non-zero and insufficient to ablate the tissue in contact with the tip, The steps include maintaining the resonant frequency of the ultrasonic handpiece while the stall mode is active, and A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above. (Claim 37) A step of receiving user input indicating the type of tissue that should remain intact, The steps include: activating the stall mode in response to the tip being positioned relative to the tissue type during the vibration of the tip; The method according to claim 36, further comprising: (Claim 38) The steps include measuring the voltage and current of the AC drive signal, The steps include determining the tissue stiffness value based on the measured voltage and current of the AC drive signal, The steps include determining whether the tissue stiffness value is greater than the stiffness threshold, The steps include: Activating the stall mode in response to determining that the tissue stiffness value is greater than the stiffness threshold; The method according to claim 36 or 37, further comprising: (Claim 39) The method according to claim 38, wherein the stiffness threshold is defined by a mechanical resistance threshold, and further comprises the step of determining the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal as the tissue stiffness value. (Claim 40) The steps include measuring the second voltage and current of the AC drive signal when the stall mode is active, The steps include determining the second mechanical resistance of the ultrasonic handpiece based on the measured second voltage and current of the AC drive signal, A step of determining whether the second mechanical resistance is less than the stiffness threshold, In response to determining that the second mechanical resistance is below the stiffness threshold, the stall mode is deactivated, the AC drive signal supplied to the ultrasonic handpiece is adjusted so that the displacement of the tip caused by the adjusted AC drive signal is at the maintained resonant frequency, and the tissue in contact with the tip can be ablated. The method according to claim 39, further comprising: (Claim 41) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, The steps include supplying the AC drive signal to the ultrasonic handpiece, The steps include measuring the voltage and current of the AC drive signal, A step of determining the characteristics of the ultrasonic handpiece associated with the tissue to be contacted by the tip, based on the measured voltage and measured current of the AC drive signal, A step of determining the target displacement of the tip based on the determined characteristics and the puncture voltage corresponding to the tissue contacted by the tip, The steps include adjusting the AC drive signal supplied to the ultrasonic handpiece to achieve the determined target displacement of the tip, A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above. (Claim 42) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, A step of determining a first displacement level of the tip, which is the maximum displacement level of the tip; A step of receiving a user selection of a first tissue response model and a second tissue response model via a user interface, wherein the second tissue response model is configured to ablate tissue that is stiffer than the first tissue response model; The steps include supplying the AC drive signal to the ultrasonic handpiece, Steps include: setting the target displacement level of the tip to the first displacement level in response to the user selection of the first tissue response model, in response to the tip being positioned relative to a first tissue type when the AC drive signal is supplied to the ultrasonic handpiece, and setting the target displacement level to a second displacement level less than the first displacement level in response to the tip being positioned relative to a second tissue type that is harder than the first tissue type when the AC drive signal is supplied to the ultrasonic handpiece; The steps of setting the target displacement level to a first displacement level in response to the user selection of the second tissue response model and in response to the tip being positioned relative to the first and second tissue types when the AC drive signal is supplied to the ultrasonic handpiece, The steps include adjusting the AC drive signal supplied to the ultrasonic handpiece to achieve the set target displacement level of the tip, and A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above. (Claim 43) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises a signal generator that generates the AC drive signal applied to the transducer, a sensor that measures the voltage of the AC drive signal, a sensor that measures the current of the AC drive signal, and a processor coupled to the sensor and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Based on the measured voltage and measured current of the AC drive signal, the mechanical resistance of the ultrasonic handpiece is determined. The target displacement of the tip portion is determined based on the aforementioned mechanical resistance, The AC drive signal output by the signal generator is adjusted to achieve the determined target displacement of the tip. A system configured to control the vibration of the tip of an ultrasonic handpiece. (Claim 44) The system according to claim 43, wherein the processor is configured to determine the target displacement of the tip such that the target displacement represents a decreased displacement of the tip, in response that the determined mechanical resistance of the ultrasonic handpiece represents an increased mechanical resistance of the ultrasonic handpiece. (Claim 45) The aforementioned processor, The determined mechanical resistance represents the increased mechanical resistance of the ultrasonic handpiece, and in response to the determined mechanical resistance being greater than the mechanical resistance threshold, the target displacement of the tip is determined such that the target displacement represents the decreased displacement of the tip. In response to the determined mechanical resistance being less than the mechanical resistance threshold, the target displacement of the tip is determined such that the target displacement represents the maximum displacement level of the tip. The system according to claim 44, configured to perform the following: (Claim 46) The aforementioned processor, Determining the capacitance of the transducer of the ultrasonic handpiece, Determining the resonant frequency of the ultrasonic handpiece, The frequency of the AC drive signal is set to the determined resonant frequency of the ultrasonic handpiece, Based on the capacitance of the transducer, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, the current flowing through the mechanical components of the ultrasonic handpiece is calculated. The mechanical resistance of the ultrasonic handpiece is calculated based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal. The system according to any one of claims 43 to 45, configured to determine the mechanical resistance of the ultrasonic handpiece by performing the following: (Claim 47) The aforementioned processor, Receiving a tissue response model that defines the target displacement of the tip as a function of the mechanical resistance, The target displacement of the tip portion is determined based on the tissue response model and the mechanical resistance. A system according to any one of claims 43 to 46, configured to perform the following: (Claim 48) The system according to claim 47, wherein the tissue response model defines a decreasing tip displacement level over increasing mechanical resistance. (Claim 49) The system according to claim 47 or 48, wherein the tissue response model defines a maximum tip displacement level associated with a first mechanical resistance threshold, a minimum tip displacement level associated with a second mechanical resistance threshold greater than the first mechanical resistance threshold, and an intermediate tip displacement level between the maximum tip displacement level and the minimum tip displacement level, associated with an intermediate mechanical resistance value between the first and second mechanical resistance thresholds, wherein the intermediate tip displacement level decreases over the intermediate mechanical resistance value. (Claim 50) The aforementioned processor, In response to the determined mechanical resistance being less than the first mechanical resistance threshold, the maximum tip displacement level is selected as the target displacement of the tip, In response to the determined mechanical resistance being greater than the second mechanical resistance threshold, the minimum tip displacement level is selected as the target displacement of the tip. In response to the determined mechanical resistance being between the first mechanical resistance threshold and the second mechanical resistance threshold, one of the intermediate tip displacement levels associated with the determined mechanical resistance is selected. The system according to claim 49, configured to perform the following: (Claim 51) The system according to claim 49 or 50, wherein at least one of the relationships between the maximum tip displacement level, the minimum tip displacement level, the first mechanical resistance threshold, the second mechanical resistance threshold, or the intermediate tip displacement level is based on user settings. (Claim 52) The system according to any one of claims 49 to 51, wherein the intermediate tip displacement level is defined by a decreasing curve function that maps the first mechanical resistance threshold to the maximum tip displacement level and the second mechanical resistance threshold to the minimum tip displacement level. (Claim 53) The system according to any one of claims 49 to 52, wherein the intermediate tip displacement level is defined according to a curve-decrease function based on the voltage corresponding to the puncture of tissue contacted by the tip of the ultrasonic handpiece. (Claim 54) The system according to claim 53, wherein the curve reduction function is further based on a resistance offset corresponding to the vibration component of the ultrasonic handpiece. (Claim 55) The system further includes a memory for storing multiple tissue response models, each of which is defined based on voltages corresponding to punctures of different tissue types, and the processor, Receiving a user selection from one of the aforementioned organizational types, To obtain the tissue response model corresponding to the selected tissue type from the memory. The system according to any one of claims 47 to 54, configured to receive the tissue response model by performing the following: (Claim 56) The system according to any one of claims 49 to 51, wherein the intermediate tip displacement level is defined by a negative linear function that maps the first mechanical resistance threshold to the maximum tip displacement level and the second mechanical resistance threshold to the minimum tip displacement level. (Claim 57) The system according to any one of claims 43 to 56, wherein the target displacement of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the processor is configured to adjust the AC drive signal output by the signal generator to achieve the determined target displacement by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece. (Claim 58) An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to a surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises: a signal generator that generates the AC drive signal applied to the transducer; a sensor that measures the voltage of the AC drive signal; a sensor that measures the current of the AC drive signal; and a processor coupled to the sensor and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Receiving a tissue response model that defines a maximum tip displacement level of the tip of the ultrasonic handpiece associated with a first tissue stiffness value, a minimum tip displacement level of the tip of the ultrasonic handpiece associated with a second tissue stiffness value greater than the first tissue stiffness value, and an intermediate tip displacement level of the tip of the ultrasonic handpiece in the range between the maximum tip displacement level and the minimum tip displacement level, wherein the intermediate tip displacement level is associated with an increasing intermediate tissue stiffness value in the range between the first tissue stiffness value and the second tissue stiffness value, and decreases as a function of the increasing intermediate tissue stiffness value. Based on the measured current and the measured voltage, the stiffness value of the tissue in contact with the tip of the ultrasonic handpiece is determined. Based on the determined stiffness value and the tissue response model, the target displacement level of the tip is determined, The AC drive signal output by the signal generator is adjusted to achieve the determined target displacement of the tip. A system that controls the vibration of the tip of an ultrasonic handpiece, which is programmed to perform this action. (Claim 59) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, The steps include supplying the AC drive signal to the transducer of the ultrasonic handpiece, The steps include measuring the voltage of the AC drive signal, The steps include measuring the current of the AC drive signal, The steps include determining the mechanical resistance of the ultrasonic handpiece based on the measured voltage and measured current of the AC drive signal, The steps include determining the target displacement of the tip portion based on the mechanical resistance, The steps include adjusting the AC drive signal to achieve the determined target displacement of the tip, A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above. (Claim 60) The method of claim 59, comprising the step of determining the target displacement of the tip such that the target displacement represents a decreased displacement of the tip in response that the determined mechanical resistance of the ultrasonic handpiece represents an increased mechanical resistance of the ultrasonic handpiece. (Claim 61) The steps include determining the target displacement of the tip such that the determined mechanical resistance represents the increased mechanical resistance of the ultrasonic handpiece, and in response that the determined mechanical resistance is greater than a mechanical resistance threshold, the target displacement represents the decreased displacement of the tip, In response to the determined mechanical resistance being less than the mechanical resistance threshold, the step of determining the target displacement of the tip such that the target displacement represents the maximum displacement level of the tip; The method according to claim 60, including the method described in claim 60. (Claim 62) The step of determining the mechanical resistance of the ultrasonic handpiece is: Determine the capacitance of the transducer of the ultrasonic handpiece. The resonant frequency of the ultrasonic handpiece is determined, The frequency of the AC drive signal is set to the determined resonant frequency of the ultrasonic handpiece. Based on the capacitance of the transducer, the measured voltage of the AC drive signal, and the measured current of the AC drive signal, the current flowing through the mechanical components of the ultrasonic handpiece is calculated. The mechanical resistance of the ultrasonic handpiece is calculated based on the current flowing through the mechanical components of the ultrasonic handpiece and the measured voltage of the AC drive signal. The method according to any one of claims 59 to 61, including the act of (Claim 63) The steps include receiving a tissue response model that defines the target displacement of the tip as a function of the mechanical resistance, A step of determining the target displacement of the tip based on the tissue response model and the mechanical resistance. The method according to any one of claims 59 to 62, further comprising: (Claim 64) The method according to claim 63, wherein the tissue response model defines a decreasing tip displacement level over increasing mechanical resistance. (Claim 65) The method according to claim 63 or 64, wherein the tissue response model defines a maximum tip displacement level associated with a first mechanical resistance threshold, a minimum tip displacement level associated with a second mechanical resistance threshold greater than the first mechanical resistance threshold, and an intermediate tip displacement level between the maximum tip displacement level and the minimum tip displacement level, associated with an intermediate mechanical resistance value between the first mechanical resistance threshold and the second mechanical resistance threshold, wherein the intermediate tip displacement level decreases over the intermediate mechanical resistance value. (Claim 66) In response to the determined mechanical resistance being less than the first mechanical resistance threshold, the step of selecting the maximum tip displacement level as the target displacement of the tip, In response to the determined mechanical resistance being greater than the second mechanical resistance threshold, the step of selecting the minimum tip displacement level as the target displacement of the tip, In response to the determined mechanical resistance being between the first mechanical resistance threshold and the second mechanical resistance threshold, the step of selecting one of the intermediate tip displacement levels associated with the determined mechanical resistance: The method according to claim 65, further comprising: (Claim 67) The method according to claim 65 or 66, wherein at least one of the relationships between the maximum tip displacement level, the first mechanical resistance threshold, the second mechanical resistance threshold, or the intermediate tip displacement level is based on user settings. (Claim 68) The method according to any one of claims 65 to 67, wherein the intermediate tip displacement level is defined by a decreasing curve function that maps the first mechanical resistance threshold to the maximum tip displacement level and the second mechanical resistance threshold to the minimum tip displacement level. (Claim 69) The method according to any one of claims 65 to 68, wherein the intermediate tip displacement level is defined according to a curve-decrease function based on the voltage corresponding to the puncture of tissue contacted by the tip of the ultrasonic handpiece. (Claim 70) The method according to claim 69, wherein the curve reduction function is further based on the resistance offset corresponding to the vibration component of the ultrasonic handpiece. (Claim 71) The memory stores multiple tissue response models, each of which is defined based on voltages corresponding to punctures of different tissue types, and the step of receiving the tissue response model is: Upon receiving a user selection from one of the aforementioned organizational types, The tissue response model corresponding to the selected tissue type is retrieved from the memory. The method according to any one of claims 63 to 70, including the act of (Claim 72) The method according to any one of claims 65 to 67, wherein the intermediate tip displacement level is defined by a negative linear function that maps the first mechanical resistance threshold to the maximum tip displacement level and the second mechanical resistance threshold to the minimum tip displacement level. (Claim 73) The method according to any one of claims 59 to 72, wherein the target displacement of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the step of adjusting the AC drive signal to achieve the determined target displacement includes adjusting the AC drive signal such that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece. (Claim 74) A method for controlling the vibration of the tip of an ultrasonic handpiece, wherein the ultrasonic handpiece defines a lumen for providing suction to a surgical site and comprises a transducer coupled to the tip, the transducer configured to vibrate the tip in response to the reception of an AC drive signal, The steps include supplying the AC drive signal to be applied to the transducer of the ultrasonic handpiece, The steps include measuring the voltage of the AC drive signal, The steps include measuring the current of the AC drive signal, Receiving a tissue response model that defines a maximum tip displacement level of the tip of the ultrasonic handpiece associated with a first tissue stiffness value, a minimum tip displacement level of the tip of the ultrasonic handpiece associated with a second tissue stiffness value greater than the first tissue stiffness value, and an intermediate tip displacement level of the tip of the ultrasonic handpiece in the range between the maximum tip displacement level and the minimum tip displacement level, wherein the intermediate tip displacement level is associated with an increasing intermediate tissue stiffness value in the range between the first tissue stiffness value and the second tissue stiffness value, and decreases as a function of the increasing intermediate tissue stiffness value. A step of determining the stiffness value of the tissue in contact with the tip of the ultrasonic handpiece based on the measured current and the measured voltage, The steps include determining the target displacement level of the tip portion based on the determined stiffness value and the tissue response model, The steps include adjusting the AC drive signal to achieve the determined target displacement of the tip, A method for controlling the vibration of the tip of an ultrasonic handpiece, comprising the above.

Claims

1. An ultrasonic handpiece comprising a tip that defines a lumen for providing suction to the surgical site, and a transducer coupled to the tip and configured to vibrate the tip in response to the reception of an AC drive signal, A control console coupled to the ultrasonic handpiece comprises a signal generator that generates the AC drive signal applied to the transducer, a sensor that measures the voltage of the AC drive signal, a sensor that measures the current of the AC drive signal, and a processor coupled to the sensor and the signal generator. A system for controlling the vibration of the tip of an ultrasonic handpiece, comprising: The aforementioned processor, Determining a first displacement level of the tip, which is the maximum displacement level of the tip, Receiving the tissue response model which defines a stiffness threshold and a plurality of second displacement levels of the tip that are each associated with different potential tissue stiffness values ​​that are smaller than the first displacement level and larger than the stiffness threshold in the tissue response model, Based on the measured voltage and current of the AC drive signal, the tissue stiffness value of the tissue contacted by the tip is determined. To determine whether the determined tissue stiffness value is less than the stiffness threshold, In accordance with the determination that the determined tissue stiffness value is less than the stiffness threshold, the target displacement level of the tip is set to the first displacement level. In response to the determination that the determined tissue stiffness value is not less than the stiffness threshold, the target displacement level of the tip portion is set to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value. The AC drive signal output to the ultrasonic handpiece by the signal generator is adjusted to achieve the set target displacement level. A system configured to control the vibration of the tip of an ultrasonic handpiece.

2. The system according to claim 1, wherein the processor is configured to determine the mechanical resistance of the ultrasonic handpiece based on the measured voltage and current of the AC drive signal as the determined tissue stiffness value, the stiffness threshold is defined by the mechanical resistance threshold, and the potential tissue stiffness value is defined by the potential mechanical resistance of the ultrasonic handpiece.

3. The system according to claim 1, wherein the tissue response model defines the second displacement level such that the second displacement level decreases as the potential tissue stiffness value increases.

4. The stiffness threshold is a first stiffness threshold, the tissue response model defines a third displacement level of the tip, which is the minimum non-zero tip displacement level of the tip and is smaller than each of the second displacement levels, and defines a second stiffness threshold that is larger than the potential tissue stiffness value, and the processor, Depending on whether the determined tissue stiffness value is greater than the first stiffness threshold and the second stiffness threshold, the target displacement level of the tip is set to the third displacement level. Depending on whether the determined tissue stiffness value is greater than the first stiffness threshold and less than the second stiffness threshold, the target displacement level of the tip is set to the second displacement level associated with the potential tissue stiffness value corresponding to the determined tissue stiffness value. A system according to any one of claims 1 to 3, configured to perform the following:

5. The system according to claim 4, wherein at least one of the first displacement level, the second displacement level, the third displacement level, the first stiffness threshold, the second stiffness threshold, or the relationship between the second displacement level and the potential structural stiffness value is based on user settings.

6. The system according to claim 4, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a negative linear function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level.

7. The system according to claim 4, wherein the relationship between the second displacement level and the potential structural stiffness value is defined by a decreasing curve function that maps the first stiffness threshold to the first displacement level and the second stiffness threshold to the third displacement level.

8. The system according to any one of claims 1 to 3, wherein the tissue response model is configured to reduce tissue ablation during the operation of the ultrasonic handpiece, and the relationship between the second displacement level and the potential tissue stiffness value is defined by a curve-declining function based on the voltage of the AC drive signal corresponding to the puncture of the tissue.

9. The system according to claim 8, wherein the curve reduction function is further based on the resistance offset corresponding to the vibration component of the ultrasonic handpiece.

10. The system according to any one of claims 1 to 3, wherein the target displacement level of the tip corresponds to a target current flowing through the mechanical components of the ultrasonic handpiece, and the processor is configured to adjust the AC drive signal output by the signal generator to achieve the set target displacement level by adjusting the AC drive signal so that the actual current flowing through the mechanical components of the ultrasonic handpiece is substantially equal to the target current flowing through the mechanical components of the ultrasonic handpiece.

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