Convergence ultrasonic treatment device

Abstract

To provide a convergence ultrasonic treatment device and a method thereof.SOLUTION: There are provided a convergence ultrasonic treatment device and a method thereof. The convergence ultrasonic treatment device includes: a convergence ultrasonic transducer for outputting a convergence ultrasonic signal including a first frequency signal range for a thermal effect and a second frequency signal range for a mechanical effect to a tissue; a cavitation sensor for detecting a cavitation signal by a cavitation phenomenon generated in the tissue by the convergence ultrasonic signal; and a processor for analyzing a cavitation detection value in the first frequency signal range and a cavitation detection value in the second frequency signal range detected through the cavitation sensor at the time of primary output of the convergence ultrasonic signal to a first region, determining whether to move to a new second region and output the convergence ultrasonic signal, or to perform secondary output of the convergence ultrasonic signal in the first region by a result of the analysis, and adjusting at least one of the output time and the frequency of the convergence ultrasonic signal when performing the secondary output of the convergence ultrasonic signal in the first region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to diagnostic and therapeutic techniques using ultrasound, and more particularly to image scanning and therapeutic techniques using focused ultrasound (FUS). [Background technology]

[0002] Ultrasound signals can be used to treat biological tissues such as cancer, tumors, and lesions. Ultrasound therapy is a method of treating lesions by outputting ultrasonic signals to lesions in the human body. Compared to general surgery and chemotherapy, ultrasound therapy can realize non-invasive treatment with relatively little trauma to the patient. Its application examples are diverse, including liver cancer, bone sarcoma, breast cancer, pancreas cancer, kidney cancer, soft tissue tumors, and pelvic tumors. Focused ultrasound (FUS) signals can be used to treat tissues such as cancer, tumors, and lesions. Treatments using focused ultrasound signals have mainly been developed as thermal ablation, which uses thermal effects to thermally cauterize tissue. However, thermal ablation has problems in that it can cause thermal damage to surrounding tissues and cause pain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Korea Publication No. 10-2023-0071056 [Patent Document 2] Korea Publication No. 10-2022-0156025 Summary of the Invention [Problem to be solved by the invention]

[0004] According to one embodiment, a focused ultrasound tissue disruption treatment method and apparatus is proposed that overcomes the limitations of thermal effects by applying mechanical effects to the focused ultrasound tissue disruption treatment, making it safer and more effective.

[0005] Furthermore, the present invention provides a focused ultrasound processing device and method capable of disrupting tissue without generating a shock wave scattering effect when applying a mechanical effect to focused ultrasound tissue disruption. [Means for solving the problem]

[0006] According to one embodiment, a focused ultrasound processing device includes a focused ultrasound transducer that outputs a focused ultrasound signal including a first frequency signal range for a thermal effect and a second frequency signal range for a mechanical effect to tissue; a cavitation sensor that detects a cavitation signal due to a cavitation phenomenon generated in tissue by the focused ultrasound signal; and a processor that analyzes a cavitation detection value of the first frequency signal range and a cavitation detection value of the second frequency signal range detected through the cavitation sensor when the focused ultrasound signal is primarily output to a first region, and determines whether to move to a new second region and output the focused ultrasound signal or to secondarily output the focused ultrasound signal to the first region according to a result of the analysis, and adjusts at least one of an output time and a frequency of the focused ultrasound signal when the focused ultrasound signal is secondarily output to the first region.

[0007] According to one embodiment, a focused ultrasound processing device includes a focused ultrasound transducer that outputs a focused ultrasound signal to tissue; a cavitation sensor that detects a cavitation signal caused by a cavitation phenomenon occurring in tissue by the focused ultrasound signal; and a processor that analyzes the cavitation signal detected through the cavitation sensor and adjusts at least one of the output time and frequency of the focused ultrasound signal based on the analysis result.

[0008] The processor can compare the cavitation detection value detected through the cavitation sensor with a predetermined cavitation threshold or cavitation limit value, and adjust at least one of the output time and frequency of the focused ultrasound signal based on the result of the comparison so that the cavitation detection value is lowered.

[0009] The processor can compare the cavitation detection value with a boiling cavitation threshold, and if the cavitation detection value is equal to or greater than the boiling cavitation threshold, adjust at least one of the output time and frequency of the focused ultrasound signal so that the cavitation detection value is lowered.

[0010] The processor can compare the cavitation detection value detected through the cavitation sensor with at least one of a boiling cavitation threshold, a non-thermal cavitation limit value, and a non-thermal cavitation threshold value, and adjust at least one of the output time and frequency of the focused ultrasound signal based on the result of the comparison.

[0011] The processor controls to output the focused ultrasound signal in a repeated multiple cycles, each cycle including a first frequency interval consisting of at least one first pulse and a second frequency interval consisting of at least one second pulse, the first frequency interval being a thermal interval for a thermal effect and the second frequency interval being a boiling interval for a mechanical effect.

[0012] The first frequency interval may include fh and Ph frequencies for thermal effects, and the second frequency interval may include fm and Pm frequencies for mechanical effects.

[0013] The processor can check the cavitation detection value within a first frequency section of a first cycle, and if the cavitation detection value is equal to or greater than the boiling cavitation limit value, control the number of first pulses in the first frequency section and the number of second pulses in the second frequency section in the second cycle following the first cycle to be reduced and increased.

[0014] The processor can check the cavitation detection value within the first frequency section of the first cycle, and if the cavitation detection value is equal to or greater than the boiling cavitation threshold, reduce the overall output time of the second cycle; if the cavitation detection value is between the boiling cavitation threshold and the non-thermal cavitation limit value, increase the number of first pulses in the first frequency section of the second cycle and reduce the number of second pulses in the second frequency section; if the cavitation detection value is between the non-thermal cavitation limit value and the non-thermal cavitation threshold value, maintain the number of first pulses in the first frequency section of the second cycle and the number of second pulses in the second frequency section; and if the cavitation detection value is equal to or less than the non-thermal cavitation threshold, reduce the number of first pulses in the first frequency section of the second cycle and increase the number of second pulses in the second frequency section.

[0015] When the processor primarily outputs the focused ultrasonic signal in the first region, the processor checks the cavitation detection value in the first frequency section of the first cycle and the cavitation detection value in the second frequency section, and if the cavitation detection value in the first frequency section is equal to or greater than the boiling cavitation threshold and the cavitation detection value in the second frequency section is equal to or greater than the non-thermal cavitation threshold, the processor controls to move to a new second region and output the focused ultrasonic signal; otherwise, the processor controls to secondary output the focused ultrasonic signal to the first region.

[0016] When the focused ultrasound signal is primarily output in the first region, the processor checks the cavitation detection value in the first frequency section of the first cycle and the cavitation detection value in the second frequency section, and if the cavitation detection value in the first frequency section or the cavitation detection value in the second frequency section is greater than or equal to the non-thermal cavitation threshold, controls to move to a new second region and output the focused ultrasound signal, and otherwise controls to secondarily output the focused ultrasound signal to the first region.

[0017] The focused ultrasound processing device further includes an input section to which tissue characteristics and treatment information are input, and the processor can determine the cavitation limit value, cavitation threshold value, output time and frequency of the focused ultrasound signal based on the input tissue characteristics and treatment information.

[0018] The processor can determine a first frequency for maximizing a thermal effect of the focused ultrasound signal prior to heat onset and a second frequency for maximizing a mechanical effect of the focused ultrasound signal after heat onset.

[0019] The processor can control the focused ultrasonic transducer to output a focused ultrasonic signal having the determined first frequency, compare the cavitation detection value with at least one of the boiling cavitation limit value and the non-thermal cavitation limit value, and if the cavitation detection value is equal to or greater than the non-thermal cavitation limit value or the boiling cavitation limit value, adjust the frequency of the focused ultrasonic signal from the first frequency to a second frequency, and then control the focused ultrasonic transducer to output a focused ultrasonic signal having the adjusted second frequency.

[0020] The focused ultrasound processing device further includes an image transducer that outputs an image ultrasound signal to the tissue and receives an ultrasound echo signal reflected from the tissue, and the processor processes the received ultrasound echo signal to generate an ultrasound image signal, analyzes the generated ultrasound image signal, and adjusts at least one of the output time and frequency of the focused ultrasound signal depending on the result of the analysis.

[0021] The processor controls to output a focused ultrasound signal by repeating a plurality of cycles, each cycle including a first frequency section consisting of at least one first pulse and a second frequency section consisting of at least one second pulse, the first frequency section being a thermal section for a thermal effect, and the second frequency section being a boiling section for a mechanical effect. The processor checks an image brightness value of a focal point within the first frequency section of the first cycle through analysis of the image signal, and if the image brightness value of the focal point is equal to or greater than a boiling cavitation image brightness limit value, the processor can control to reduce the number of first pulses in the first frequency section in the second cycle and increase the number of second pulses in the second frequency section.

[0022] The processor controls the device to output the focused ultrasound signal by repeating a plurality of cycles, each cycle including a first frequency section including at least one first pulse and a second frequency section including at least one second pulse, the first frequency section being a thermal section for a thermal effect, and the second frequency section being an effervescent section for a mechanical effect. The processor checks an image brightness value of a focal point within the first frequency section of the first cycle through analysis of the image signal, and if the image brightness value of the focal point is equal to or greater than an effervescent cavitation image brightness value, reduces the entire output time of the second cycle, and controls the image brightness value of the focal point to be equal to or greater than an effervescent cavitation image brightness value. and the non-thermal cavitation image brightness limit value, the number of first pulses in the first frequency section of the second cycle is increased and the number of second pulses in the second frequency section is decreased; if the image brightness value of the focal area is between the non-thermal cavitation image brightness limit value and the non-thermal cavitation image brightness threshold value, the number of first pulses in the first frequency section of the second cycle and the number of second pulses in the second frequency section are maintained; and if the image brightness value of the focal area is equal to or lower than the non-thermal cavitation image brightness threshold value, the number of first pulses in the first frequency section of the second cycle is decreased and the number of second pulses in the second frequency section is increased.

[0023] According to another embodiment, a focused ultrasound processing method using a focused ultrasound processing device includes a step of determining a first output condition including at least one of an output time and a frequency of a focused ultrasound signal; a step of outputting a focused ultrasound signal to tissue under the determined first output condition through a focused ultrasound transducer; a step of detecting a cavitation signal caused by a cavitation phenomenon occurring in tissue by the outputted focused ultrasound signal through a cavitation sensor; a step of analyzing a cavitation detection value detected through the cavitation sensor, and adjusting an output condition including at least one of an output time and a frequency of the focused ultrasound signal to a second output condition according to a result of the analysis; and a step of outputting a focused ultrasound signal to tissue under the adjusted second output condition through the focused ultrasound transducer.

[0024] The step of adjusting the output condition to the second output condition includes the steps of: checking a cavitation detection value within a first frequency section of the first cycle when a focused ultrasound signal is output to tissue during a first cycle under the first output condition; and, if the cavitation detection value is equal to or greater than a boiling cavitation threshold value, reducing the number of first pulses in the first frequency section and increasing the number of second pulses in the second frequency section under the second output condition of a second cycle; each cycle includes a first frequency section consisting of at least one first pulse and a second frequency section consisting of at least one second pulse, the first frequency section being a thermal section for a thermal effect, and the second frequency section being a boiling section for a mechanical effect.

[0025] The step of adjusting the output condition to the second output condition includes the steps of: checking a cavitation detection value within a first frequency section of the first cycle when a focused ultrasound signal is output to tissue during a first cycle under the first output condition; if the cavitation detection value is equal to or greater than a boiling cavitation threshold, reducing the total output time under the second output condition of the second cycle; if the cavitation detection value is between the boiling cavitation threshold and a non-thermal cavitation threshold, increasing the number of first pulses in the first frequency section and reducing the number of second pulses in the second frequency section under the second output condition of the second cycle; if the cavitation detection value is between the boiling cavitation threshold and a non-thermal cavitation threshold, and if the cavitation detection value is below the non-thermal cavitation threshold, reducing the number of first pulses in the first frequency section and increasing the number of second pulses in the second frequency section under the second output condition of the second cycle. Each cycle includes a first frequency section consisting of at least one first pulse and a second frequency section consisting of at least one second pulse, the first frequency section being a thermal section for a thermal effect and the second frequency section being a boiling section for a mechanical effect.

[0026] The step of adjusting the output condition to the second output condition includes a step of checking a cavitation detection value in a first frequency section of the first cycle and a cavitation detection value in a second frequency section when the focused ultrasonic signal is primarily output for the first region; and a step of controlling to move to a new second region and output the focused ultrasonic signal if the cavitation detection value in the first frequency section is equal to or greater than a boiling cavitation threshold and the cavitation detection value in the second frequency section is equal to or greater than a non-thermal cavitation threshold, and otherwise controlling to output the focused ultrasonic signal to the first region for a second time; each cycle includes a first frequency section consisting of at least one first pulse and a second frequency section consisting of at least one second pulse, the first frequency section being a thermal section for a thermal effect, and the second frequency section being a boiling section for a mechanical effect.

[0027] The step of adjusting the output condition to the second output condition includes a step of checking a cavitation detection value in a first frequency section of the first cycle and a cavitation detection value in a second frequency section when the focused ultrasonic signal is primarily output for the first region; and a step of controlling to move to a new second region and output the focused ultrasonic signal if the cavitation detection value in the first frequency section or the cavitation detection value in the second frequency section is equal to or greater than a non-thermal cavitation threshold, and otherwise controlling to output the focused ultrasonic signal to the first region for a second time; each cycle includes a first frequency section consisting of at least one first pulse and a second frequency section consisting of at least one second pulse, the first frequency section being a thermal section for a thermal effect, and the second frequency section being a boiling section for a mechanical effect. Effect of the Invention

[0028] According to one embodiment of a focused ultrasound processing device and method thereof, as a mechanical effect is applied in focused ultrasound tissue ablation, tissue can be ablated more safely and effectively by going beyond the limits of thermal effects.

[0029] Furthermore, when applying a mechanical effect to focused ultrasound tissue ablation, the pressure and strength of the focused ultrasound signal can be reduced by adjusting the frequency or output time of the focused ultrasound signal using the cavitation signal and the ultrasound image signal, thereby enabling tissue to be ablated without generating a shock wave scattering effect.Also, the accuracy of treatment can be improved by locally generating bubbles and controlling the size and duration of the bubbles. [Brief description of the drawings]

[0030] [Figure 1] 1 is a diagram showing a configuration of a focused ultrasound processing device according to an embodiment of the present invention; [Diagram 2] 1 is a flowchart showing a focused ultrasound processing method according to an embodiment of the present invention. [Diagram 3]1 is a diagram showing a cavitation detection value according to an embodiment of the present invention and a cavitation limit value and a cavitation threshold value to be compared; [Figure 4] 4 is a diagram showing signal waveforms illustrating an example of adjusting an output time of a focused ultrasound signal according to an embodiment of the present invention; [Diagram 5] 4 is a diagram illustrating a signal waveform for explaining an example of adjusting an output time of a focused ultrasound signal according to an embodiment of the present invention in more detail; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The advantages and features of the present invention, and the method of achieving the same, will become clear from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. The present embodiments are provided merely to complete the disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

[0032] In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may obscure the gist of the present invention, the detailed description will be omitted, and the terms described below are defined to reflect the functions in the embodiments of the present invention, and may vary depending on the intentions or practices of users or operators, etc. Therefore, the definitions must be based on the overall contents of this specification.

[0033] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following exemplary embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the following detailed embodiments. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

[0034] FIG. 1 is a diagram showing the configuration of a focused ultrasound processing apparatus according to an embodiment of the present invention.

[0035] The focused ultrasound processing device 1 according to an embodiment can physically remove soft tissue using not only the thermal effect of the focused ultrasound signal but also the physical effect of the focused ultrasound signal. This technology, called "focused ultrasound soft tissue removal technology" or "boiling histotripsy," is a technology that physically breaks tissue by artificially generating an acoustic cavitation phenomenon at the focal position using a pressure several tens of times stronger than the acoustic pressure used in the focused ultrasound signal.

[0036] However, in the focused ultrasound tissue disruption technique, a shock wave scattering effect may occur in which secondary microbubbles are simultaneously generated not only at the focal position but also around the focal position. The focused ultrasound tissue disruption technique has the advantage of being able to physically disrupt tissue, but is difficult to apply when tissue or tumors located close to major organs and blood vessels must be removed because the accuracy is reduced due to the shock wave scattering effect. The focused ultrasound processing device 1 according to an embodiment can disrupt tissue without generating the shock wave scattering effect in the focused ultrasound tissue disruption technique.

[0037] The configuration of a focused ultrasound processing device 1 having the above-mentioned characteristics will be described below with reference to FIG.

[0038] Referring to FIG. 1, a focused ultrasound processing device 1 includes a focused ultrasound pulse generator 10, a focused ultrasound transducer 11, a diagnostic ultrasound pulse generator 12, an image transducer 13, a processor 14, a cavitation sensor 15, an input section 16, a storage section 17 and an output section 18.

[0039] The focused ultrasonic pulse generator 10 generates a pulsed driving signal having a pulse repetition frequency (PRF, hereinafter referred to as “PRF”) and a duty, and transmits it to the focused ultrasonic transducer 11 .

[0040] The focused ultrasound transducer 11 converts an electrical waveform, which is a driving signal received from the focused ultrasound pulse generator 10, into a focused ultrasound signal and outputs the converted focused ultrasound signal to tissue. At this time, a temperature rise occurs in the local tissue through the transmission of ultrasound energy within the tissue. The focused ultrasound signal is a high intensity focused ultrasound (HIFU).

[0041] The image transducer 13 outputs an image ultrasound signal into the tissue by a short pulse electric signal, which is a drive signal received from the diagnostic ultrasound pulse generator 12, and receives an ultrasound echo signal reflected from the tissue. The image transducer 13 receives the ultrasound echo signal until the next pulse is generated, and transmits it to the processor 14. The focused ultrasound processing device 1 has a structure in which an image transducer 13 is located at the center and focused ultrasound transducers 11 are arranged around the center. However, the structure of the image transducer 13 and the focused ultrasound transducer 11 is not limited to this and can be modified in various ways.

[0042] The focused ultrasound processing apparatus 1 according to the embodiment performs a treatment operation using focused ultrasound from the focused ultrasound transducer 11 and simultaneously obtains a diagnostic image using image ultrasound from the image transducer 13 .

[0043] The focused ultrasound signal output from the focused ultrasound transducer 11 may cause cavitation in tissue. The cavitation phenomenon means that when the ultrasound signal comes into contact with tissue, small bubbles are formed due to the action of negative and positive pressures caused by pressure changes in the tissue, and the process of these bubbles becoming as large as possible and exploding is repeated, destroying cells in the tissue. The cavitation phenomenon causes bubbles to vibrate and collapse due to acoustic pressure changes, generating shock waves. The boiling histotripsy technology can destroy tissue through shock waves generated by the cavitation phenomenon.

[0044] The cavitation sensor 15 detects a cavitation signal generated by the cavitation phenomenon from the tissue.

[0045] The boiling histotripsy method can cause a shock wave scattering effect in which secondary microbubbles are generated simultaneously not only at the focal point of the tissue but also around it. The bubble cloud generated by the unintended shock wave scattering effect can cause impacts at points other than the focal point, damaging undesired tissue sites.

[0046] Thus, the focused ultrasound processing device 1 according to an embodiment attempts to disrupt tissue without generating a shock wave scattering effect. For example, the processor 14 analyzes a cavitation detection signal detected through the cavitation sensor 15, and adjusts at least one of the output time and frequency of the focused ultrasound signal according to the analysis result, thereby preventing the shock wave scattering effect. The processor 14 adjusts at least one of the output time and frequency of the focused ultrasound signal through the analysis of the cavitation detection signal, thereby precisely controlling the movement change of bubbles so that there is no shock wave scattering effect.

[0047] More specifically, the processor 14 compares the cavitation detection value detected through the cavitation sensor 15 with the boiling cavitation threshold value, and if the cavitation detection value is equal to or greater than the boiling cavitation threshold value, adjusts at least one of the output time and frequency of the focused ultrasonic signal so that the cavitation detection value is lowered. An embodiment of this will be described later with reference to Figs. 2 and 5.

[0048] The processor 14 can determine the primary and secondary outputs of the focused ultrasound signal to the first region, the movement and output from the first region to the second region (next tissue region), the interruption of the output of the focused ultrasound signal, the duration of the output of the focused ultrasound signal, etc., depending on the magnitude of the cavitation signal. An embodiment of this will be described later with reference to Figs. 2 and 4.

[0049] The processor 14 can analyze the image ultrasound signal and adjust at least one of the output time and frequency of the focused ultrasound signal according to the analysis result. To this end, the processor 14 receives an ultrasound echo signal from the image transducer 13, converts it into a digital signal, and generates an ultrasound image signal through image processing. At this time, the processor 14 can analyze the generated ultrasound image signal and adjust at least one of the output time and frequency of the focused ultrasound signal according to the analysis result. An embodiment of this will be described later with reference to FIGS. 2 and 5.

[0050] The output unit 18 outputs the ultrasound image. The storage unit 17 stores information required for the signal analysis by the processor 14 or stores information analyzed by the processor 14.

[0051] FIG. 2 is a flowchart showing a method for focused ultrasonic processing according to an embodiment of the present invention.

[0052] 1 and 2, the focused ultrasound processing device 1 receives tissue characteristics and treatment information from a user (210). The tissue characteristics information may include tissue thickness information. The treatment information may include treatment depth and treatment range.

[0053] Next, the focused ultrasound processing device 1 determines a first output condition including at least one of an output time and a frequency of the focused ultrasound signal, reflecting the characteristics of the tissue and the treatment information (220). Furthermore, the focused ultrasound processing device 1 may set a boiling cavitation threshold, a boiling cavitation limit value, a non-thermal cavitation threshold value, a non-thermal cavitation limit value, etc. for determining the first output condition. Each of the above-mentioned cavitation values ​​will be described later with reference to FIG. 3. The focused ultrasound processing device 1 may store the first output condition in the storage unit 17.

[0054] Next, the focused ultrasound processing device 1 outputs a focused ultrasound signal to the tissue through the focused ultrasound transducer 11 under the determined first output condition (230).

[0055] Next, the focused ultrasound processing device 1 detects a cavitation signal caused by a cavitation phenomenon occurring in tissue due to the output focused ultrasound signal through the cavitation sensor 15 (240).

[0056] Subsequently, the focused ultrasonic processing device 1 analyzes the cavitation detection signal detected through the cavitation sensor 15, and adjusts the output conditions including at least one of the output time and frequency of the focused ultrasonic signal to a second output condition according to the analysis result.

[0057] For example, the focused ultrasonic processing device 1 compares the cavitation signal detected through the cavitation sensor 15 with the boiling cavitation threshold value to determine whether the cavitation detection value is equal to or greater than the boiling cavitation threshold value (250). At this time, if the cavitation detection value is equal to or greater than the boiling cavitation threshold value, at least one of the output conditions of the output time and frequency of the focused ultrasonic signal is adjusted to a second output condition (260).

[0058] Subsequently, the focused ultrasound processing device 1 outputs a focused ultrasound signal to the tissue under the adjusted second output condition through the focused ultrasound transducer (270).

[0059] An embodiment in which the output time is adjusted as an output condition will be described below.

[0060] First, the focused ultrasound output section is composed of a plurality of cycles, and each cycle includes a first frequency section composed of at least one first pulse and a second frequency section composed of at least one second pulse. In this case, the first frequency section is a thermal section for a thermal effect, and the second frequency section is a boiling section for a mechanical effect.

[0061] In the step of adjusting to the second output condition (260), the focused ultrasonic processing device 1 compares the cavitation detection value detected through the cavitation sensor with a predetermined cavitation threshold or cavitation limit value, and adjusts at least one of the output time and frequency of the focused ultrasonic signal according to the result of the comparison so that the cavitation detection value becomes lower. This method can be classified into a method using a boiling condition and a method not using a boiling condition.

[0062] As an example of a method using a boiling condition, the focused ultrasonic processing device 1 compares the cavitation detection value with the boiling cavitation threshold value. At this time, if the cavitation detection value is equal to or greater than the boiling cavitation threshold value, the focused ultrasonic processing device 1 can adjust at least one of the output time and frequency of the focused ultrasonic signal so that the cavitation detection value becomes lower.

[0063] As an example of a method that does not utilize a boiling condition, the focused ultrasonic processing device 1 can compare the cavitation detection value with at least one of a boiling cavitation threshold, a non-thermal cavitation limit value, and a non-thermal cavitation threshold value, and adjust at least one of the output time and frequency of the focused ultrasonic signal according to the result of the comparison. An embodiment of this will be described later with reference to FIG.

[0064] An embodiment in which the frequency is adjusted as an output condition will be described below.

[0065] In the first output condition determination step (220), the focused ultrasound processing device 1 determines a first frequency for maximizing the thermal effect of the focused ultrasound signal before heat generation, and a second frequency for maximizing the mechanical effect of the focused ultrasound signal after heat generation.

[0066] Subsequently, in a focused ultrasound signal output step (230) for a first output condition, the focused ultrasound processing device 1 outputs focused ultrasound of a first frequency to the tissue.

[0067] Subsequently, in the adjustment step (260) to the second output condition, the focused ultrasonic processing device 1 compares the cavitation detection value with the boiling cavitation limit value and the non-thermal cavitation limit value, and if the cavitation detection value is equal to or greater than at least one of the boiling cavitation limit value and the non-thermal limit value, adjusts the frequency of the focused ultrasonic signal from the first frequency to the second frequency.

[0068] Subsequently, in a step (270) of outputting a focused ultrasound signal to a second output condition, the focused ultrasound processing device 1 outputs focused ultrasound of the adjusted second frequency to the tissue.

[0069] An embodiment in which the focused ultrasound processing device 1 determines the first frequency for maximizing the thermal effect of the focused ultrasound signal before heat generation will be described below.

[0070] The sound absorption coefficient α(f) of tissue increases with increasing frequency.

[0071]

number

[0072] , where α0 is the sound absorption coefficient at 1 MHz, and f is the frequency in MHz.

[0073] Depending on the treatment depth, there is a frequency at which maximum sound absorption is achieved.

[0074] The amount of heat generated, Q(z), is given by:

[0075] Amount of heat generated

[0076]

number

[0077] where α is the sound absorption coefficient, z is the treatment depth, and f is the frequency in MHz.

[0078] Continuing, differentiating the amount of heat generated Q(z) gives:

[0079]

number

[0080] The first frequency f, which is the maximum heat generation frequency at which the differentiated value of the heat generation amount Q(z) becomes zero, is a function of the sound absorption coefficient α and the treatment depth z as follows:

[0081]

number

[0082] An embodiment in which the focused ultrasound processing device 1 determines the second frequency for maximizing the mechanical effect of the focused ultrasound signal after heat generation will be described below.

[0083] The focused ultrasonic processing device 1 can determine the second frequency f using a mechanical index as follows:

[0084] Mechanical Index=

[0085]

number

[0086] where Pr is the rarefactional pressure and f is the frequency.

[0087] Meanwhile, the focused ultrasound processing device 1 may analyze not only the cavitation detection signal but also the ultrasound image signal, and adjust at least one of the output time and frequency of the focused ultrasound signal according to the analysis result of the image signal. An embodiment of this will be described later with reference to FIG.

[0088] FIG. 3 is a diagram showing a cavitation limit value and a cavitation threshold value to be compared with a cavitation detection value according to an embodiment of the present invention.

[0089] Referring to FIG. 3, the focused ultrasonic processing device 1 can compare the cavitation detection value with the boiling cavitation limit value, the boiling cavitation threshold value, the non-thermal cavitation limit value, and the non-thermal cavitation threshold value, respectively.

[0090] The sections to be compared with the cavitation detection value are divided into (1) section above the boiling cavitation limit value, (2) section between the boiling cavitation limit value and the boiling cavitation threshold value, (3) section between the boiling cavitation threshold value and the non-thermal cavitation limit value, (4) section between the non-thermal cavitation limit value and the non-thermal cavitation threshold value, and (5) section below the non-thermal cavitation threshold value.

[0091] The boiling cavitation limit value, boiling cavitation threshold value, non-thermal cavitation limit value, and non-thermal cavitation threshold value are preset to reflect inputted tissue characteristics and treatment information, and can be changed by the user.

[0092] FIG. 4 is a diagram showing signal waveforms illustrating an example of adjusting the output time of a focused ultrasound signal according to an embodiment of the present invention.

[0093] Referring to Figures 1 and 4, the focused ultrasound processing device 1 can determine the primary and secondary output of the focused ultrasound signal to a first region, movement and output from the first region to a second region (next tissue region), interruption of the output of the focused ultrasound signal, and duration of the output of the focused ultrasound signal, depending on the magnitude of the cavitation signal.

[0094] First, the focused ultrasound output section is composed of a plurality of cycles, and each cycle includes a first frequency section composed of at least one first pulse and a second frequency section composed of at least one second pulse. In this case, the first frequency section is a thermal section for a thermal effect, and the second frequency section is a boiling section for a mechanical effect.

[0095] As an example of using boiling conditions, the focused ultrasound device 1 targets a first region and when the cavitation detection value in a first frequency range is above the boiling cavitation threshold and the cavitation detection value in a second frequency range is above the non-thermal cavitation threshold, it moves to a new second region and outputs a focused ultrasound signal.

[0096] In other cases, the focused ultrasound device 1 outputs a focused ultrasound signal to the first region as a first output, and then outputs a focused ultrasound signal to the first region as a second output. This embodiment is an example in which a boiling condition is utilized for tissue disruption.

[0097] As an example of a case where the boiling condition is not used, the focused ultrasound device 1 moves to a new second region and outputs a focused ultrasound signal when the cavitation detection value in the first frequency range or the cavitation detection value in the second frequency range for the first region is equal to or greater than the non-thermal cavitation threshold. In other cases, the focused ultrasound device 1 can output a second focused ultrasound signal to the first region. This embodiment is an example of a case where the boiling condition is not used for tissue disruption.

[0098] Meanwhile, the focused ultrasound processing device 1 can adjust the frequency or output time of the second cycle when it outputs a focused ultrasound signal to the first region during a first cycle after first outputting the focused ultrasound signal to the first region during a second cycle.

[0099] For example, the focused ultrasonic processing device 1 may output a focused ultrasonic signal in which N first pulses for a thermal effect and M second pulses for a mechanical effect are combined in a first cycle, and then output a focused ultrasonic signal in which the number of N and M is changed and combined while maintaining the same total number of pulses in a second cycle. A detailed description of this will be given later with reference to FIG.

[0100] FIG. 5 is a diagram showing a detailed signal waveform illustrating an example of adjusting the output time of a focused ultrasound signal according to an embodiment of the present invention.

[0101] The focused ultrasound output section is composed of a plurality of cycles, and each cycle includes a first frequency section composed of at least one first pulse 51 and a second frequency section composed of at least one second pulse 52. In this case, the first frequency section is a thermal section for a thermal effect, and the second frequency section is a boiling section for a mechanical effect.

[0102] 1 and 5, a focused ultrasonic processing device 1 outputs a focused ultrasonic signal by combining a first pulse for a thermal effect of an ultrasonic signal and a second pulse for a mechanical effect.

[0103] For example, the focused ultrasound processing device 1 can generate N (N is a positive integer) first pulses 51 and M (M is a positive integer) second pulses 52 per cycle, combine the N first pulses 51 and the M second pulses 52 to generate one pulse, and output the pulse one by one per cycle through the focused ultrasound transducer.

[0104] The first pulse 51 is a long burst pulse signal, and the second pulse 52 is a short burst pulse signal. The first pulse 51 may include an fh frequency for a thermal effect and a Pulse Length Ph frequency. The second pulse 52 may include an fm frequency for a mechanical effect and a Pulse Length Pm frequency.

[0105] At this time, the focused ultrasonic processing device 1 can combine various frequencies, and combinations of fh≠fm, Ph≠Pm, fh=fm, Ph≠Pm, and fh≠fm, Ph=Pm are possible.

[0106] The focused ultrasonic processing device 1 checks the cavitation detection value in the first frequency section of the first cycle. If the cavitation detection value is equal to or greater than the boiling cavitation threshold value (section (1) in FIG. 3), the focused ultrasonic processing device 1 reduces the number of first pulses 51 in the first frequency section and increases the number of second pulses 52 in the second frequency section in the second cycle to output a focused ultrasonic signal.

[0107] For example, if the cavitation detection value is equal to or greater than the boiling cavitation threshold at the point where Na first pulses 51 are output among N first pulses in the first cycle, the focused ultrasonic processing device 1 reduces the number of first pulses 51 to generate Na first pulses, and outputs the remaining M+a second pulses 52 after generating them. This method is an embodiment that utilizes boiling conditions.

[0108] As another example, an embodiment that does not utilize boiling conditions is described below.

[0109] If the cavitation detection value is equal to or higher than the boiling cavitation threshold (section (2) in FIG. 3), the focused ultrasonic processing device 1 reduces the total output time of the second cycle and outputs a focused ultrasonic signal.

[0110] In contrast, if the cavitation detection value is between the boiling cavitation threshold and the non-thermal cavitation limit value (section (3) in Figure 3), the focused ultrasound processing device 1 increases the number of first pulses 51 in the first frequency section of the second cycle and decreases the number of second pulses 52 in the second frequency section to output a focused ultrasound signal.

[0111] If the cavitation detection value is between the non-thermal cavitation limit value and the non-thermal cavitation threshold value (section (4) in Figure 3), the focused ultrasound processing device 1 outputs a focused ultrasound signal while maintaining the number of first pulses 51 in the first frequency section of the second cycle and the number of second pulses 52 in the second frequency section.

[0112] If the cavitation detection value is below the non-thermal cavitation threshold (section (5) in Figure 3), the focused ultrasound processing device 1 reduces the number of first pulses 51 in the first frequency section of the second cycle and increases the number of second pulses 52 in the second frequency section to output a focused ultrasound signal.

[0113] This allows the focused ultrasound treatment device 1 to generate bubbles locally and control the size and duration of the bubbles to enhance the accuracy of treatment.

[0114] Meanwhile, the focused ultrasound processing device 1 can further analyze the ultrasound image signal and adjust at least one of the output time and frequency of the focused ultrasound signal according to the analysis result.

[0115] For example, when using the boiling condition, the focused ultrasound processing device 1 checks the image brightness value of the focal point in the first frequency range of the first cycle through the analysis of the image signal during the first cycle. At this time, if the image brightness value of the focal point is equal to or greater than the boiling cavitation image brightness limit value, the focused ultrasound processing device 1 reduces the number of first pulses 51 in the first frequency range in the second cycle and increases the number of second pulses 52 in the second frequency range to output a focused ultrasound signal.

[0116] For example, when the boiling condition is not used, the focused ultrasound processing device 1 checks the image brightness value of the focal point within the first frequency range of the first cycle through the analysis of the image signal during the first cycle. At this time, if the image brightness value of the focal point is equal to or greater than the boiling cavitation image brightness value, the focused ultrasound processing device 1 reduces the total output time of the second cycle and outputs the focused ultrasound signal.

[0117] In contrast, if the image brightness value of the focal area is between the boiling cavitation image brightness value and the non-thermal cavitation image brightness limit value, the focused ultrasound processing device 1 increases the number of first pulses 51 in the first frequency section of the second cycle and decreases the number of second pulses 52 in the second frequency section to output a focused ultrasound signal.

[0118] In contrast, if the image brightness value of the focal area is between the non-thermal cavitation image brightness limit value and the non-thermal cavitation image brightness threshold value, the focused ultrasound processing device 1 outputs a focused ultrasound signal while maintaining the number of first pulses 51 in the first frequency section of the second cycle and the number of second pulses 52 in the second frequency section.

[0119] In contrast, if the image brightness value of the focal area is below the non-thermal cavitation image brightness threshold, the focused ultrasound processing device 1 reduces the number of first pulses 51 in the first frequency section of the second cycle and increases the number of second pulses 52 in the second frequency section to output a focused ultrasound signal.

[0120] The present invention has been described above with reference to its preferred embodiments. Those skilled in the art will understand that the present invention can be embodied in modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an explanatory perspective, not a limiting perspective. The scope of the present invention is defined in the claims, not the above description, and all differences within the scope of the claims should be interpreted as being included in the present invention.

Claims

1. a focused ultrasound transducer for outputting a focused ultrasound signal to tissue, the focused ultrasound signal including a first frequency signal range for a thermal effect and a second frequency signal range for a mechanical effect; a cavitation sensor for detecting a cavitation signal caused by a cavitation phenomenon generated in tissue by a focused ultrasound signal; A processor that analyzes the cavitation detection value of the first frequency signal range and the cavitation detection value of the second frequency signal range detected through the cavitation sensor when the focused ultrasonic signal is primarily output to the first region, and determines whether to move to a new second region and output the focused ultrasonic signal or to secondarily output the focused ultrasonic signal to the first region according to the analysis result, and adjusts at least one of the output time and frequency of the focused ultrasonic signal when the focused ultrasonic signal is secondarily output to the first region; 13. A focused ultrasonic treatment device comprising:

2. The processor Controlling the device to output a focused ultrasonic signal by repeating a plurality of cycles; Each cycle includes a first frequency interval consisting of at least one first pulse and a second frequency interval consisting of at least one second pulse; 2. The focused ultrasonic treatment apparatus of claim 1, wherein the first frequency range is a thermal range for a thermal effect and the second frequency range is a boiling range for a mechanical effect.

3. The first frequency interval includes the fh and Ph frequencies for thermal effects; The focused ultrasonic processing apparatus of claim 2 , wherein the second frequency section includes an fm frequency and a Pm frequency for a mechanical effect.

4. The processor The focused ultrasound processing apparatus of claim 1, further comprising: determining a first frequency for maximizing a thermal effect of the focused ultrasound signal before heat generation; and determining a second frequency for maximizing a mechanical effect of the focused ultrasound signal after heat generation.

5. The focused ultrasonic processing device is an imaging transducer for outputting an imaging ultrasound signal to the tissue and receiving an ultrasound echo signal reflected from the tissue; The processor The received ultrasonic echo signal is processed to generate an ultrasonic image signal; The focused ultrasound processing apparatus according to claim 1 , further comprising: analyzing the generated ultrasound image signal; and adjusting at least one of an output time and a frequency of the focused ultrasound signal according to a result of the analysis.

6. The processor Controlling the device to output a focused ultrasonic signal by repeating a plurality of cycles; Each cycle includes a first frequency interval consisting of at least one first pulse and a second frequency interval consisting of at least one second pulse; The first frequency interval is a thermal interval for thermal effects and the second frequency interval is a boiling interval for mechanical effects; The processor By analyzing the image signal, the image luminance value of the focal point is confirmed within a first frequency section of a first cycle; The focused ultrasound processing apparatus of claim 5, further comprising a control for decreasing the number of first pulses in the first frequency range in the second cycle and increasing the number of second pulses in the second frequency range when the image brightness value of the focal area becomes equal to or greater than the boiling cavitation image brightness limit value.

7. The processor Controlling the device to output a focused ultrasonic signal by repeating a plurality of cycles; Each cycle includes a first frequency interval consisting of at least one first pulse and a second frequency interval consisting of at least one second pulse; The first frequency interval is a thermal interval for thermal effects and the second frequency interval is a boiling interval for mechanical effects; The processor By analyzing the image signal, the image luminance value of the focal point is confirmed within a first frequency section of a first cycle; If the image brightness value of the focal area is equal to or greater than the effervescent cavitation image brightness value, reduce the total output time of the second cycle; If the image brightness value of the focal area is between the boiling cavitation image brightness value and the non-thermal cavitation image brightness limit value, increase the number of first pulses in the first frequency section of the second cycle and decrease the number of second pulses in the second frequency section; If the image brightness value of the focal area is between the non-thermal cavitation image brightness limit value and the non-thermal cavitation image brightness threshold value, the first pulse number in the first frequency section and the second pulse number in the second frequency section of the second cycle are maintained; The focused ultrasound processing device of claim 5, characterized in that if the image brightness value of the focal area is below a non-thermal cavitation image brightness threshold, the number of first pulses in the first frequency section of the second cycle is reduced and the number of second pulses in the second frequency section is increased.

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