Ultrasonic focal region regulation and control system and method for realizing local compound motion of focal region in superficial tissue

Abstract

The invention discloses an ultrasonic focal region regulation and control system and method for realizing focal region local composite motion in superficial tissue. The ultrasonic focal region regulation and control system comprises a transducer, a cavity, a regulation and control structure and an acoustic Fresnel zone plate FZP, under the adjusting effect of the adjusting structure, the ultrasonic generator can reciprocate in the axial direction of the cavity and is used for adjusting the focal region form of the ultrasonic waves emitted by the transducer, so that the ultrasonic waves irradiate the cells at the target position. The system can effectively regulate and control the form of the focal region of the sound field, so that the effects of generating a variable force field effect on tissues in the range of the focal region, uniformly outputting energy, expanding the action area and improving the cell irradiation effect and safety are achieved. According to the ultrasonic cell irradiation device, the complexity of a traditional ultrasonic cell irradiation device in the operation process is reduced, the operation frequency and difficulty are greatly reduced, a cell irradiator can more concentrate on optimization of a treatment scheme, and meanwhile treatment convenience and efficiency are effectively improved. A high-precision sound field regulation and control technology is combined with a humanized mechanical design.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an ultrasonic focal region control system and method for realizing localized compound motion of focal regions within superficial tissues. Background Art

[0002] Ultrasound refers to sound waves with a frequency higher than 20kHz. It has the advantages of strong directionality, good penetration, and easy concentration of sound energy. Therefore, it has been widely used in the medical field. Ultrasonic cell irradiation equipment converts electrical energy into ultrasonic energy through a high-frequency electric power generator, and applies it to cells with the help of a treatment head. In in vitro clinical experiments, it is mostly used to study the effects of ultrasound on cell permeability, proliferation, apoptosis, etc., to evaluate the effects of ultrasound in tumor treatment, tissue regeneration, etc., and to verify the safety and effectiveness of ultrasound in disease treatment.

[0003] Ultrasonic cell irradiation mainly relies on its thermal effect, mechanical effect, cavitation effect and sonochemical effect: 1. Thermal effect: Promote local blood circulation and metabolism by generating heat; 2. Mechanical effect: When ultrasonic waves propagate in the medium, they produce periodic pressure changes, affecting the cell membrane and internal structure. At the same time, sound waves produce flow in the liquid, affecting the surrounding environment and cell function of the cells through micro-vibration and massage. 3. Cavitation effect: Inertial cavitation causes bubbles to expand and burst rapidly, generating high-energy shock waves; in addition, non-inertial cavitation causes bubbles to oscillate in the sound field, generating microflows and shear forces; 4. Sonochemical effect: Ultrasonic waves generate free radicals in liquids, triggering chemical reactions. Used to enhance drug release and cell killing.

[0004] The cell irradiation effect of focused ultrasound depends largely on whether the focal area morphology meets specific requirements. The ideal focal area is usually in the shape of a long ellipsoid or cigar, and its major and minor axis ratios must be appropriate to ensure that the energy is evenly distributed in the target area while minimizing damage to surrounding tissues. However, existing ultrasound cell irradiation equipment still has the following problems in practical applications: The treatment depth and focal area are relatively fixed, and the treatment mode is relatively single; The effect of cell irradiation is highly dependent on the operator's technical level, and the equipment is difficult to promote and apply.

[0005] In order to solve the above problems, researchers began to explore the design of acoustic artificial structures to achieve more flexible and precise control of sound waves. Acoustic artificial structures can effectively regulate the propagation path and focusing effect of sound waves through specific geometric configurations and material properties, thus providing a new technical approach for more precise treatment and imaging. In this context, Fresnel Zone Plate (FZP), as an acoustic artificial structure with special structure and function, has gradually become a research hotspot due to its excellent ability in wavefront control and sound focusing. As an acoustic lens based on the Fresnel diffraction principle, the acoustic Fresnel zone plate (FZP) can achieve a variety of focusing modes by precisely controlling the sound waves, providing an effective way to solve the problem of the single treatment mode of traditional ultrasonic cell irradiation equipment. Compared with traditional acoustic lenses, the Fresnel zone plate has the significant advantages of flexible structure, light weight and low cost. By adjusting the number, thickness, width and material parameters of the Fresnel zone, the focal length, focal size and focusing efficiency of the lens can be flexibly adjusted, thereby achieving precise control of the acoustic field morphology. For example, the study of Daniel et al. showed that by optimizing the radius of the central ring of FZP, the side lobes can be effectively suppressed and the lateral resolution can be improved; the study of Liu et al. further revealed the linear relationship between the radial width of the outermost ring of FZP and the lateral focal spot size, providing a theoretical basis for the precise design of the focal morphology; Calvo et al. proposed an ultra-thin FZP structure through innovative material design, which significantly improved the acoustic field gain. These studies fully demonstrate the excellent ability of Fresnel zone plates in acoustic field control, making it an ideal choice for realizing diversified treatment modes.

[0006] In addition, in order to reduce the difficulty of using the equipment and reduce the dependence on the operator's technical level, the Fresnel zone plate can be combined with a miniaturized motion mechanism to achieve dynamic changes in focal length through mechanical adjustment. This design not only avoids frequent manual adjustments in traditional equipment, but also significantly improves the convenience of operation and treatment efficiency. For example, by integrating a micro-stepping motor or piezoelectric drive, FZP can achieve precise focal length adjustment within a small range, thereby adapting to treatment needs of different depths and morphologies. This semi-automatic operation method not only lowers the threshold for using the equipment, but also provides technical support for the promotion and application of ultrasonic cell irradiation equipment.

[0007] Therefore, there is a need for a focal regulation system that can regulate the focal area within superficial tissues. Summary of the invention

[0008] In view of this, an object of the present invention is to provide an ultrasonic focal range control system for realizing localized compound motion of the focal range within superficial tissue, wherein the system realizes ultrasonic focal range control by combining an acoustic Fresnel zone plate with a motion mechanism.

[0009] In order to achieve the above object, the present invention provides the following technical solutions: The ultrasonic focal region control system for realizing localized compound motion of focal region in superficial tissue provided by the present invention comprises a transducer, a cavity, a control structure, and an acoustic Fresnel zone plate FZP; The transducer is connected to the cavity, and the acoustic Fresnel zone plate FZP is arranged on the cavity. The acoustic Fresnel zone plate FZP is arranged on the adjustment structure, and can reciprocate along the axial direction of the cavity under the adjustment of the adjustment structure, so as to adjust the focal zone shape of the ultrasonic wave emitted from the transducer, so that the ultrasonic wave irradiates the cells at the target position.

[0010] Further, the control structure includes a driving mechanism and a FZP clamp assembly; The acoustic Fresnel zone plate FZP is arranged on a FZP fixture assembly, and the FZP fixture assembly is connected to a driving mechanism and moves axially along the cavity under the action of the driving mechanism.

[0011] Furthermore, the driving mechanism includes a motor and a connecting rod mechanism; The motor is connected to the FZP clamp assembly through a connecting rod mechanism. The FZP clamp assembly is used to clamp the FZP. Under the driving action of the motor, the FZP clamp assembly is moved through the connecting rod mechanism, thereby driving the acoustic Fresnel zone plate FZP set on the FZP clamp assembly to perform periodic reciprocating motion along the axial direction in the cavity.

[0012] Further, the FZP fixture assembly includes a fixing bracket and an adjusting screw; The fixing bracket is arranged on the cavity wall, the fixing bracket is connected to the connecting mechanism, and the fixing bracket is used to clamp and fix the acoustic Fresnel zone plate FZP; the adjusting screw is arranged on the fixing bracket, and is used to adjust the clamping tension of the acoustic Fresnel zone plate FZP by the fixing bracket.

[0013] Furthermore, a scale is provided on the shell of the cavity for marking the displacement of the acoustic Fresnel zone plate FZP, or / and A flexible sound-permeable membrane is arranged on the cavity, and a closed cavity is formed between the flexible sound-permeable membrane and the outer shell, and degassed water is arranged inside the cavity.

[0014] Furthermore, the transducer is connected via a transducer interface disposed on the cavity, and the transducer interface connection is threaded.

[0015] Furthermore, the size of the acoustic Fresnel zone plate FZP is determined according to the following formula: in, is the total number of rings of the acoustic Fresnel zone plate, is to set the focal length, λ is the wavelength of the sound wave; Represents the total number of rings of the acoustic Fresnel zone plate; Indicates the distance between the sound source and the zone plate; Represents the radius of each zone of the Fresnel zone plate.

[0016] Furthermore, the acoustic Fresnel zone plate FZP is a phase inversion type Fresnel zone plate, and the thickness of the phase inversion zone of the FZP is such that the phase difference between the phase inversion zone and the acoustic transparent zone is an odd multiple of π.

[0017] Furthermore, the acoustic impedance of the flexible sound-permeable membrane matches the acoustic impedance of human tissue, and the acoustic transmission coefficient τ of the selected material is calculated according to the following formula: Where Γ is the reflection coefficient of the soft silicone zone plate; is the acoustic impedance of the lens; is the acoustic impedance of water; Is an imaginary unit.

[0018] The control method provided by the present invention using the above-mentioned ultrasound focal area control system for realizing localized compound movement of focal areas in superficial tissues comprises the following steps: Step 1. Prepare the ultrasound focal range control system and set the control parameters; Step 2. Focal area morphology control Initial focal zone setting: Start the system and adjust the Fresnel zone plate to the initial position to form the default focal zone shape; Adjustment of focal zone shape: By designing the ring structure and control system of the Fresnel zone plate, the position of the zone plate in the acoustic system is changed, the phase distribution of the sound field is changed, and thus the major-minor axis ratio of the focal zone is adjusted; Step 3. Focus position movement Focus reciprocating motion: Activate the intracavitary reciprocating motion function of the Fresnel zone plate, so that the focus can reciprocate in a small range along the depth direction in the superficial tissue; Motion parameter adjustment: adjust the amplitude, frequency and trajectory of the focus movement to ensure uniform energy distribution and expand the effective area; Step 4. Cell irradiation Start irradiation: start the ultrasonic therapy gun to irradiate the cell sample; Dynamic regulation: During the irradiation process, the focal morphology and focal position are dynamically adjusted according to the real-time monitoring results to ensure that the cells are subjected to a uniform and effective force field. Step 5. Record and save the data.

[0019] The beneficial effects of the present invention are: The ultrasonic focal region control system for realizing localized compound motion of focal region in superficial tissue provided by the present invention can realize the ultrasonic focal region control system for compound reciprocating motion of focal region in superficial tissue within a certain range. The system is connected to an acoustic Fresnel zone plate that can realize reciprocating motion in the cavity outside the treatment gun, so as to realize the control of focal region morphology (long-short axis ratio of focal region) that can effectively control the sound field, and at the same time, the change of focal region morphology is adjusted by localized focal position (focal length) motion, so as to achieve the force field effect of changing tissue within the focal region, and the movement of the focal position can realize the reciprocating action of small-range deep and shallow positions in the cell irradiation process, output energy evenly, and expand the action area. Thereby improving the cell irradiation effect and safety. The system reduces the complexity of traditional ultrasonic cell irradiation equipment in the operation process, and provides an important basis for the semi-automatic operation of the cell irradiation process. The operator can realize precise stimulation and massage of the target area without frequent movement of position, which greatly reduces the frequency and difficulty of operation, enables cell irradiators to focus more on the optimization of treatment plans, and effectively improves the convenience and efficiency of treatment. By combining high-precision sound field control technology with humanized mechanical design, The control structure of this system can effectively adjust the ratio of the major and minor axes of the focal area while realizing the dynamic movement of the local focal position (focal length) and the redistribution of target energy. By precisely controlling the focal area morphology, a changing force field can be applied to the tissue within the focal area, thereby achieving precise mechanical stimulation of tissues at different depths and ranges. At the same time, the dynamic movement of the focal position enables the cell irradiation process to achieve reciprocating action between deep and shallow positions within a small range of superficial tissue, ensuring uniform distribution of energy in the tissue and expanding the effective area of ​​action. This dual control mechanism not only significantly improves the coverage and effect of cell irradiation, but also enhances the safety and controllability of treatment by avoiding excessive or low local energy. Ultimately, this design provides an efficient, precise and safe solution for acoustic cell irradiation, with broad application prospects.

[0020] This regulatory structure achieves a composite mode of mechanical stimulation and uniform energy distribution in superficial tissues through the reciprocating motion of FZP and dynamic regulation of focal zone morphology, significantly improving the coverage, therapeutic effect and safety of cell irradiation while reducing operational complexity. It is suitable for medical fields such as tumor treatment and tissue regeneration.

[0021] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for explanation.

[0023] Figure 1 This is the front view of the regulatory structure.

[0024] Figure 2 It is a side view of the regulatory structure.

[0025] Figure 3 This is the front view of the assembly of the control structure and transducer.

[0026] Figure 4 It is the side view of the assembly of the control structure and the transducer.

[0027] Figure 5 Schematic diagram of the effect on cell culture dishes.

[0028] Figure 6 This is a 3D printed model of the Fresnel zone plate.

[0029] Figure 7 Schematic diagram of the focusing principle of Fresnel zone plate.

[0030] Figure 8 Flow chart of the ultrasound focal area control method for achieving localized compound movement in the focal area of ​​superficial tissue.

[0031] Fig. 9 This is the changing trend of the focal area major-minor axis ratio and focal length as the position of the Fresnel zone plate changes.

[0032] Fig.10 It is the changing trend of the major axis and minor axis of the focal area during the reciprocating motion.

[0033] In the figure, 1 represents the control structure, 2 represents the transducer, 3 represents the cell culture dish, 4 represents the bracket, 11 represents the motor, 12 represents the connecting rod system, 13 represents the FZP clamp assembly, 14 and 15 represent the fixing screws, 16 represents the acoustic Fresnel zone plate FZP, 17 represents the graduated slide rail, 18 represents the flexible sound-transmitting membrane, and 19 represents the transducer interface. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0035] Example 1 like Figure 1 and Figure 2As shown, the ultrasonic focal region control system for realizing localized compound motion of focal region in superficial tissue provided by this embodiment includes a transducer, a cavity, a control structure, and an acoustic Fresnel zone plate FZP; The transducer is connected to the cavity, the acoustic Fresnel zone plate FZP is arranged on the cavity, and the acoustic Fresnel zone plate FZP is arranged on the adjustment structure. Under the adjustment of the adjustment structure, it can reciprocate along the axial direction of the cavity, and is used to adjust the focal zone shape (long-short axis ratio) of the ultrasound emitted from the transducer, so that the ultrasound can irradiate the cells at the target position; The acoustic Fresnel zone plate FZP in this embodiment is arranged in the cavity in a movable manner so as to be movable along the axial direction of the cavity; at the same time, the major-minor axis ratio of the focal area of ​​the ultrasonic wave emitted from the transducer can be adjusted.

[0036] The control structure in this embodiment includes a driving mechanism and a FZP fixture assembly; the acoustic Fresnel zone plate FZP is arranged on the FZP fixture assembly, and the FZP fixture assembly is connected to the driving mechanism and moves along the axial direction of the cavity under the action of the driving mechanism; The driving mechanism in this embodiment includes a motor and a connecting rod mechanism; The motor is connected to the FZP fixture assembly through a connecting rod mechanism. The FZP fixture assembly is used to clamp the FZP. Under the driving action of the motor, the FZP fixture assembly is moved through the connecting rod mechanism, thereby driving the acoustic Fresnel zone plate FZP set on the FZP fixture assembly to perform periodic reciprocating motion along the axial direction in the cavity. The motion amplitude and speed are adjustable to achieve dynamic changes in the focal zone morphology. The FZP clamp assembly in this embodiment includes a fixing bracket and an adjusting screw; The fixed bracket is arranged on the cavity wall, the fixed bracket is connected to the connecting mechanism, and the fixed bracket is used to clamp and fix the acoustic Fresnel zone plate FZP; the adjusting screw is arranged on the fixed bracket, and is used to adjust the clamping tension of the acoustic Fresnel zone plate FZP by the fixed bracket; it is adapted to FZP of different sizes to achieve rapid replacement and maintenance.

[0037] The shell of the cavity provided in this embodiment is provided with a scale ruler for marking the displacement of the acoustic Fresnel zone plate FZP; the shell is a transparent shell; The cavity in this embodiment is provided with a flexible sound-permeable membrane, and a closed cavity is formed between the flexible sound-permeable membrane and the outer shell. Degassed water is arranged inside to compensate for pressure fluctuations through piston movement, thereby ensuring stable transmission of ultrasonic energy.

[0038] The transducer in this embodiment is connected via a transducer interface disposed on the cavity, and the transducer interface connection is threaded connection; it may also be internal threaded connection.

[0039] The acoustic Fresnel zone plate FZP in this embodiment is used to generate interference and diffraction phenomena by setting different annular zones to generate phase differences for different wavelengths; the FZP in this embodiment is an annular phase inversion structure, and its annular zone width and phase difference are precisely designed to control the amplitude, phase and direction of the sound wave; the FZP is made of a material close to the acoustic impedance of human tissue, including soft silicone or vulcanized rubber, and is used to reduce the attenuation of sound energy and dynamically adjust the major-minor axis ratio and focal length of the focal zone; in this embodiment, the amplitude, phase and direction of the sound wave can be controlled, and the major-minor axis ratio of the focal zone of the sound field can be dynamically adjusted by changing its position to achieve periodic changes in the focal zone morphology; This embodiment changes the periodic change of the focal zone's major-minor axis ratio by changing the relative position between the acoustic Fresnel zone plate and the sound source. When the relative position between the sound source and the Fresnel zone plate changes, this change follows a periodic pattern, causing the major-minor axis ratio of the focal zone to also show corresponding periodic fluctuations. This device drives the Fresnel zone plate to perform precise reciprocating motion within a preset range through a high-performance motor drive. This movement process actually dynamically adjusts the relative position relationship between the sound source and the zone plate, thereby causing the size of the focal zone to change periodically. This change not only affects the geometric shape of the focal zone, but also leads to the redistribution of energy within the focal zone, presenting a state of dynamic equilibrium.

[0040] The driving mechanism in this embodiment is used to drive the FZP clamp assembly to perform reciprocating motion to achieve periodic changes in the focal area's major-minor axis ratio and dynamic adjustment of the focal length; the reciprocating motion range of the driving mechanism is 1-10 mm, and the motion frequency is 0.1-5 Hz. The periodic changes in the focal area's major-minor axis ratio and dynamic adjustment of the focal length are achieved by adjusting the motor parameters. The driving mechanism integrates a micro stepping motor or a piezoelectric driver, and achieves millimeter-level precision displacement adjustment through a closed-loop control system.

[0041] The driving mechanism in this embodiment includes a motor and a connecting rod system. The motor is connected to the FZP through the connecting rod to drive the FZP to perform periodic reciprocating motion along the axial direction in the cavity. The motion amplitude and speed are adjustable to achieve dynamic changes in the focal zone morphology. The motor is a micro-stepping motor or a piezoelectric driver, and the FZP movement amplitude and frequency are precisely adjusted through closed-loop control. The focal zone major-minor axis ratio and focal length change periodically with the FZP position.

[0042] The FZP fixture assembly in this embodiment is used to fix the position of the acoustic Fresnel zone plate FZP, firmly install the FZP in the cavity, and ensure the linear accuracy of its reciprocating motion.

[0043] The FZP fixture assembly in this embodiment includes a detachable bracket and fixing screws, which are suitable for FZPs of different sizes to achieve quick replacement and maintenance.

[0044] The housing with a scale in this embodiment is a transparent structure with a fixed driving mechanism and FZP inside. A scale is provided on the surface of the housing for real-time observation and calibration of the motion range of the FZP. The scale of the housing has an accuracy of 0.1 mm and is used to quantify the displacement of the acoustic Fresnel zone plate and associate it with the trend of focal zone morphology changes to achieve real-time optimization of treatment parameters.

[0045] The scale of the housing in this embodiment is linked to the motor drive signal to adjust the FZP position through real-time feedback to optimize the treatment parameters.

[0046] Flexible sound-transmitting membrane: Covering the front end of the shell, it is made of waterproof and pressure-resistant soft silicone material, and filled with degassed water to balance the cavity pressure to ensure that the ultrasonic energy is efficiently coupled to the target tissue; In this embodiment, a closed cavity is formed between the flexible sound-permeable membrane and the outer shell, and the degassed water inside compensates for pressure fluctuations through piston movement, ensuring stable transmission of ultrasonic energy.

[0047] like Figure 3 and Figure 4 As shown, in this embodiment, the control structure (including the driving mechanism and the FZP fixture assembly) is connected to the ultrasonic transducer through the transducer interface to form a complete sound field output system; The Fresnel zone plate in this embodiment is fixed to the inside of the shell by a clamp, the connecting rod of the driving mechanism is mechanically connected to the clamp, the flexible sound-transmitting membrane is sealed and installed at the front end of the shell, and the transducer interface is arranged at the rear end of the shell. The components work together to realize dynamic regulation of the focal area morphology and periodic reciprocating motion of the focal position.

[0048] After the control structure in this embodiment is assembled with the transducer, the long axis of the focal area fluctuates periodically with the change of the position of the Fresnel zone plate, the short axis remains stable, and the uniformity of the energy distribution in the focal area is improved by 20%-40%.

[0049] like Figure 5 and Figure 6 As shown, the device of this embodiment can realize compound reciprocating motion of the focal area in the superficial tissue within a certain range, and the cell culture dish is placed above the wave zone plate to achieve the cell irradiation effect. By dynamically adjusting the major-minor axis ratio of the focal area and optimizing the energy distribution in the focal area, a compound mode effect on the target area during the cell irradiation process can be achieved.

[0050] When sound waves pass through the acoustic Fresnel zone plate, sound waves of different wavelengths will interfere and diffract due to the phase difference between different rings on the zone plate.

[0051] The precise control of the phase difference in this embodiment is the key to achieving sound wave focusing. First, the Fresnel zone plate regulates the phase and amplitude of the sound wave through alternating transparent (sound-transmitting) and opaque (sound-insulating) ring-shaped structures. The radius design of the ring-shaped belt is generated based on the above-mentioned Fresnel zone formula. The width and position of each ring-shaped belt determine the phase change when the sound wave passes through, thereby affecting the interference and diffraction behavior of the sound wave. When the sound wave passes through the Fresnel zone plate, different ring-shaped belts will introduce a specific phase delay or advance to the sound wave, thereby accurately controlling the propagation characteristics of the sound wave: the transparent ring-shaped belt allows the sound wave to pass through, and the phase remains basically unchanged. The opaque ring-shaped belt blocks the sound wave, which is equivalent to introducing a π phase difference (half-wavelength delay). By alternating transparent and opaque ring-shaped belts, the zone plate forms a periodic phase modulation structure on the sound wave propagation path. This modulation causes the sound wave to produce coherent superposition after passing through different ring-shaped belts, and finally forms an enhanced sound field at the focus. When sound waves of different wavelengths pass through the same Fresnel zone plate, different interference and diffraction effects will be produced due to the different relationship between the wavelength and the ring-shaped belt size. By adjusting the width and position of the annular zone, the response of the zone plate to sound waves of different wavelengths can be optimized to achieve multi-wavelength control or wavelength selective focusing.

[0052] By precisely designing the zone width and phase difference of the zone plate, the amplitude, phase and direction of the sound wave can be precisely controlled, with significant sound wave control capabilities and focusing effects. By changing the position of the FZP in the acoustic system, the ratio of the major and minor axes of the focal area can be controlled within a certain range, and this law is periodic, so this law can be applied to cell irradiation applications.

[0053] The structure in this embodiment is adapted to the front end of the ultrasonic transducer, and the dynamic force field effect and uniform energy distribution of the target tissue are realized through compound reciprocating motion, thereby expanding the effective action area. The motor and connecting rod system are used to drive the Fresnel zone plate to reciprocate in the cavity, while adjusting the movement amplitude and speed; a transparent shell equipped with a scale is convenient for observing the movement range of the zone plate and optimizing the treatment parameters in real time: a waterproof and pressure-resistant soft silicone material is used for pressure compensation during piston movement in a cavity filled with degassed water and to achieve better ultrasonic coupling. Through the device of the present invention, a composite mode of cell irradiation effect can be achieved on the target treatment area, reducing the operator's operation frequency, and improving the user experience and convenience of operation of ultrasonic cell irradiation equipment.

[0054] Example 2 This embodiment further illustrates the present invention. The Fresnel zone plate (FZP) of this embodiment is a core component. Under the drive of a motor and the action of a multifunctional fixture, the zone plate can achieve reciprocating motion in the cavity of the device. The acoustic Fresnel zone plate (FZP) can control the amplitude, phase and direction of the sound wave through its precise design, and can effectively change the major-minor axis ratio of the focal range of the sound field. The specific parameters of the acoustic Fresnel zone plate are as follows: like Figure 7 As shown, in actual application, the position and depth of cell irradiation and the working frequency of the treatment head are determined, and the size of the Fresnel zone plate is designed based on this. The specific design method can refer to the following expression: in, is the total number of rings of the Fresnel zone plate, is to set the focal length, λ is the wavelength of the sound wave; Indicates the distance between the sound source and the zone plate; Indicates the radius of each zone of the Fresnel zone plate; This embodiment uses a phase reversal type Fresnel zone plate, and the thickness of the phase reversal zone of the FZP is such that the phase difference between it and the acoustic transparent zone is an odd multiple of π.

[0055] Phase Difference | |, , are the acoustic wave numbers of the lens and the immersion medium, respectively.

[0056] in, Indicates the phase difference between different rings; represents the acoustic wave number of the lens; represents the acoustic wave number of the medium in which the lens is immersed; The wavelength of the sound wave representing the lens material; Indicates the wavelength of sound waves immersed in the medium; represents pi; The material of the Fresnel zone plate of this embodiment is soft silicone or vulcanized rubber, and the thickness of the lens is The following formula can be used for calculation: Among them, q is an odd number, that is, the thickness of the lens is An odd multiple of .

[0057] In actual situations, materials with acoustic impedance close to that of human tissue can be selected as the material of the zone plate, such as soft silicone, vulcanized rubber, etc., which have a higher transmission coefficient to reduce energy attenuation.

[0058] The acoustic impedance of the flexible sound-permeable membrane of this embodiment matches the acoustic impedance of human tissue, and the acoustic transmission coefficient τ of the selected material can be expressed by the following expression: Where Γ is the reflection coefficient of the soft silicone zone plate, and its value can be expressed as: in, is the acoustic impedance of the lens, is the acoustic impedance of water, Represents an imaginary unit; the reflection coefficient Γ is determined by the difference between the acoustic impedance of the material and the acoustic impedance of water.

[0059] From the wavefront analysis of the sound wave passing through the Fresnel zone plate and the law of conservation of energy, the sound pressure function near the focus can be obtained as: Where F is the focal length, P0 is the initial sound pressure, k is the wave number, (x) is a zero-order first-kind Bessel function used to describe the focal energy distribution, η is the acoustic axis direction of the sound field, γ is the radial direction of the zone plate perpendicular to the acoustic axis, and α is the central angle formed by the maximum radius of the zone plate and the focal area. The focused sound field of the FZP in this embodiment satisfies the above sound pressure distribution function.

[0060] like Figure 8 As shown, this embodiment also provides a control method using an ultrasonic focal region control system that realizes localized compound movement of the focal region in the superficial tissue, and the focal region morphology is changed by operation to achieve the best effect. The specific process is as follows: Step 1. System preparation: Equipment inspection: Ensure that the ultrasonic treatment gun, external motion device, control system and power supply connection are normal; Parameter setting: preset basic parameters such as ultrasonic frequency, power, irradiation time, etc. according to experimental requirements; Experimental system construction: Design the Fresnel zone plate according to the experimental parameters, fix the zone plate inside the motion device, and match it with the ultrasonic treatment gun; Sample preparation: Fix the cell sample to be irradiated (such as a culture dish or tissue model) on the laboratory bench and ensure that it is aligned with the sound field of the ultrasound treatment gun.

[0061] Step 2. Focal area morphology control Initial focal zone setting: Start the system and adjust the Fresnel zone plate to the initial position to form the default focal zone shape; Adjustment of focal zone shape: By designing the ring structure and control system of the Fresnel zone plate, the position of the zone plate in the acoustic system is changed, the phase distribution of the sound field is changed, and thus the major-minor axis ratio of the focal zone is adjusted; Real-time monitoring: Use sound field detection equipment (such as a sound pressure meter or sound field imaging system) to monitor changes in focal area morphology in real time to ensure that the adjustment effect meets expectations.

[0062] Step 3. Focus position movement Focus reciprocating motion: Activate the intracavitary reciprocating motion function of the Fresnel zone plate, so that the focus performs a small range of reciprocating motion in the depth direction (axial direction) within the superficial tissue; Motion parameter adjustment: According to experimental requirements, adjust the amplitude, frequency and trajectory of the focus movement to ensure uniform energy distribution and expand the effective area.

[0063] Step 4. Cell irradiation Start irradiation: start the ultrasonic therapy gun to irradiate the cell sample; Dynamic regulation: During the irradiation process, the focal morphology and focal position are dynamically adjusted according to the real-time monitoring results to ensure that the cells are subjected to a uniform and effective force field. Irradiation time control: According to the experimental design, control the irradiation time to avoid overheating or insufficient energy.

[0064] Step 5. Data recording and analysis Experimental data recording: record the parameters during irradiation (such as focal morphology, focal position, acoustic field intensity, etc.) and cell responses (such as morphological changes, survival rate, etc.); Result analysis: Compare the cell irradiation effects under different focal morphologies and focus motion parameters, and optimize the system parameters.

[0065] Key Operation Notes in This Method 1. Focal area morphology adjustment: By designing the ring structure of the Fresnel zone plate and controlling the position of the zone plate in the acoustic system, the phase distribution of the sound field is adjusted. The focal area morphology is monitored in real time to ensure that the adjustment effect meets the experimental requirements.

[0066] 2. Focal position movement: Start the motion device to drive the reciprocating motion of the Fresnel zone plate, so that the focus moves in the depth direction in the superficial tissue. Adjust the motion parameters (amplitude, frequency) to optimize the energy distribution. During the irradiation process, dynamically adjust the focal area morphology and focal position according to the real-time monitoring results to ensure that the cells are subjected to a uniform and effective force field.

[0067] This experimental method achieves dynamic control of the ultrasound focal morphology and focal position by precisely regulating the ring structure and motion parameters of the Fresnel zone plate, thereby optimizing the cell irradiation effect. The experimental process is clear and the operation steps are clear, which can effectively verify the performance and application potential of the system.

[0068] Taking f=250kHz, F=12mm, and n=11 as an example, through COMSOL MUTIPHYSICS numerical simulation, we know that by changing the position of the acoustic Fresnel zone plate, the major-minor axis ratio of the focal area has a certain periodic change, and the acoustic focal length will also change periodically within a certain range of the set value, such as Fig. 9 shown.

[0069] The designed Fresnel zone plate is embedded in the structure and fixed with a clamp screw. The reciprocating motor drives the Fresnel zone plate to reciprocate in the cavity through the connecting rod. At this time, the reciprocating Fresnel zone plate causes the major-minor axis ratio of the focal area to change periodically, such as Fig.10 As shown in the figure, the major axis of the focal region is the one that causes periodic changes during the position change, while the minor axis of the acoustic focal region remains basically stable. Therefore, the energy in the focal region can be redistributed, and the automatic massage effect of the target area can be achieved in cell irradiation applications.

[0070] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. An ultrasonic focal region control system for realizing localized compound movement of focal regions within superficial tissues, characterized in that: It includes a transducer, a cavity, a regulating structure and an acoustic Fresnel zone plate FZP; the transducer is connected to the cavity, the acoustic Fresnel zone plate FZP is arranged on the cavity, and the acoustic Fresnel zone plate FZP is arranged on the regulating structure. Under the regulating action of the regulating structure, the acoustic Fresnel zone plate FZP can reciprocate along the axial direction of the cavity, and is used to adjust the focal zone shape of the ultrasound emitted from the transducer, so that the ultrasound can irradiate the cells at the target position.

2. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 1, characterized in that: The regulating structure comprises a driving mechanism and a FZP fixture assembly; the acoustic Fresnel zone plate FZP is arranged on the FZP fixture assembly, and the FZP fixture assembly is connected to the driving mechanism and moves axially along the cavity under the action of the driving mechanism.

3. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 2, characterized in that: The driving mechanism includes a motor and a connecting rod mechanism; the motor is connected to the FZP clamp assembly through the connecting rod mechanism, and the FZP clamp assembly is used to clamp the FZP. Under the driving action of the motor, the FZP clamp assembly is moved through the connecting rod mechanism, thereby driving the acoustic Fresnel zone plate FZP set on the FZP clamp assembly to perform periodic reciprocating motion along the axial direction in the cavity.

4. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 2, characterized in that: The FZP clamp assembly includes a fixed bracket and an adjusting screw; the fixed bracket is arranged on the cavity wall, the fixed bracket is connected to the connecting mechanism, and the fixed bracket is used to clamp and fix the acoustic Fresnel zone plate FZP; the adjusting screw is arranged on the fixed bracket, and is used to adjust the clamping tension of the fixed bracket on the acoustic Fresnel zone plate FZP.

5. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 1, characterized in that: The shell of the cavity is provided with a scale for marking the displacement of the acoustic Fresnel zone plate FZP, or / and the cavity is provided with a flexible sound-permeable membrane, a closed cavity is formed between the flexible sound-permeable membrane and the outer shell, and degassed water is arranged inside.

6. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 1, characterized in that: The transducer is connected via a transducer interface arranged on the cavity, and the transducer interface connection adopts a threaded connection.

7. The ultrasonic focal region control system for realizing localized compound motion of focal regions in superficial tissues according to claim 1, characterized in that: The size of the acoustic Fresnel zone plate FZP is determined according to the following formula: in, is the total number of rings of the acoustic Fresnel zone plate, is to set the focal length, λ is the wavelength of the sound wave; Indicates the distance between the sound source and the zone plate; Represents the radius of each zone of the Fresnel zone plate.

8. The ultrasonic focal region control system for realizing localized compound movement of focal regions in superficial tissues according to claim 1, characterized in that: The acoustic Fresnel zone plate FZP is a phase inversion type Fresnel zone plate, and the thickness of the phase inversion zone of the FZP is such that the phase difference between the phase inversion zone and the acoustic transparent zone is an odd multiple of π.

9. The ultrasonic focal region control system for realizing localized compound movement of focal regions in superficial tissues according to claim 5, characterized in that: The acoustic impedance of the flexible sound-permeable membrane matches the acoustic impedance of human tissue, and the acoustic transmission coefficient τ of the selected material is calculated according to the following formula: Where Γ is the reflection coefficient of the soft silicone zone plate; is the acoustic impedance of the lens; is the acoustic impedance of water; Is an imaginary unit.

10. A control method using the ultrasound focal region control system for realizing localized compound movement of focal regions in superficial tissues according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1. Prepare the ultrasound focal range control system and set the control parameters; Step 2. Focal area morphology control Initial focal zone setting: Start the system and adjust the Fresnel zone plate to the initial position to form the default focal zone shape; Adjustment of focal zone shape: By designing the ring structure and control system of the Fresnel zone plate, the position of the zone plate in the acoustic system is changed, the phase distribution of the sound field is changed, and thus the major-minor axis ratio of the focal zone is adjusted; Step 3. Focus position movement Focus reciprocating motion: Activate the intracavitary reciprocating motion function of the Fresnel zone plate, so that the focus can reciprocate in a small range along the depth direction in the superficial tissue; Motion parameter adjustment: adjust the amplitude, frequency and trajectory of the focus movement to ensure uniform energy distribution and expand the effective area; Step 4. Cell irradiation Start irradiation: start the ultrasonic therapy gun to irradiate the cell sample; Dynamic regulation: During the irradiation process, the focal morphology and focal position are dynamically adjusted according to the real-time monitoring results to ensure that the cells are subjected to a uniform and effective force field. Step 5. Record and save the data.

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