An ultrasonic excitation plaster patch administration control method and system

Abstract

This invention provides a method and system for controlling drug delivery via ultrasound-induced medicated plaster patches. The method includes acquiring initial operating parameters of an ultrasound transducer and real-time physiological characteristic data of the drug recipient; constructing a sound field tissue interaction model based on this data; generating dynamic focusing control commands to drive the ultrasound transducer to emit focused ultrasound signals towards the medicated plaster patch to stimulate drug release; real-time acquisition of temperature and displacement feedback signals from the medicated plaster patch's interaction area; updating the dynamic focusing control commands based on the feedback signals and driving the ultrasound transducer to continue emitting focused ultrasound signals, thus achieving closed-loop controlled drug delivery. This invention enables precise, safe, and controllable transdermal drug delivery.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a method and system for controlling the administration of an ultrasonically excited medicated plaster patch. Background Technology

[0002] Transdermal drug delivery, as a non-invasive method of drug administration, is widely used in the treatment of chronic diseases and local analgesia due to its advantages such as avoiding the first-pass effect in the liver, reducing gastrointestinal irritation, and maintaining stable blood drug concentrations. Traditional transdermal drug delivery mainly relies on the passive diffusion of drugs through the stratum corneum of the skin due to their own physicochemical properties. However, the stratum corneum, as the body's natural barrier, severely limits the transdermal absorption efficiency of most drugs, especially large molecule drugs and hydrophilic drugs, which are difficult to penetrate effectively. To improve transdermal efficiency, researchers have developed a variety of physical permeation-enhancing techniques, including iontophoresis, electroporation, microneedle arrays, and ultrasound-guided delivery. Among them, ultrasound-guided delivery utilizes the cavitation, thermal, and mechanical effects of ultrasound waves to disrupt the lipid structure of the stratum corneum, increasing skin permeability and exhibiting a good permeation-enhancing effect.

[0003] In recent years, with the development of ultrasound transducer technology and focused ultrasound technology, focused ultrasound can precisely concentrate sound energy into tissues at specific depths, increasing local sound energy density while reducing damage to surrounding tissues, providing a new technical pathway for precise transdermal drug delivery. Simultaneously, the development of intelligent control technology and multi-sensor fusion technology has made it possible to monitor tissue physiological parameters in real time and dynamically adjust treatment parameters. However, existing transdermal ultrasound drug delivery technologies mostly focus on optimizing single ultrasound parameters or designing a fixed-focus sound field, lacking the ability to adaptively adjust to individual physiological differences and making it difficult to dynamically optimize the drug delivery process based on real-time tissue response. Furthermore, the application of ultrasound energy in existing technologies often lacks effective safety monitoring mechanisms, posing risks of local overheating or tissue damage, and cannot intelligently control the drug delivery process based on the drug release state, resulting in low drug delivery efficiency and insufficient safety. Summary of the Invention

[0004] This invention provides a method and system for controlling the administration of medicated plaster patches via ultrasound excitation.

[0005] In a first aspect of the present invention, a method for controlling drug delivery using an ultrasonically stimulated medicated plaster patch is provided, comprising: The initial operating parameters of the ultrasonic transducer were obtained, and real-time physiological characteristic data of the subjects to be drugged were acquired. Based on the initial working parameters and the real-time physiological characteristic data, a sound field tissue action model is constructed; Based on the sound field organization model, a dynamic focusing control command is generated; According to the dynamic focusing control command, the ultrasonic transducer is driven to emit focused ultrasonic signals toward the plaster patch to stimulate the plaster patch to release the drug. Real-time acquisition of temperature and displacement feedback signals from the area of ​​action of the plaster patch; Based on the temperature feedback signal and the displacement feedback signal, the dynamic focusing control command is updated, and the ultrasonic transducer is driven to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

[0006] Furthermore, the acquisition of the initial operating parameters of the ultrasonic transducer and the acquisition of real-time physiological characteristic data of the subject to be drugged include: The center frequency, initial sound pressure amplitude, initial focusing focal point size, and pulse repetition frequency of the pre-stored ultrasonic transducer are read as the initial operating parameters. The skin surface temperature of the subject to be administered the drug is collected by an infrared sensor, the skin tissue thickness of the subject to be administered the drug is collected by an ultrasonic echo ranging method, and the skin surface impedance value of the subject to be administered the drug is collected by an impedance measurement unit. The skin surface temperature, the skin tissue thickness, and the skin surface impedance value are used as the real-time physiological characteristic data. The real-time physiological feature data is time-synchronized and aligned, and the aligned real-time physiological feature data is compared with a preset standard physiological parameter range. When the real-time physiological feature data is within the standard physiological parameter range, a sound field tissue action model is constructed.

[0007] Furthermore, the step of constructing a sound field organization and action model based on the initial working parameters and the real-time physiological characteristic data includes: Based on the initial sound pressure amplitude, initial focusing focal size, and pulse repetition frequency in the initial working parameters, a sound field distribution function including spatial sound pressure distribution and time duty cycle is established; Based on the skin tissue thickness and skin surface impedance value in the real-time physiological characteristic data, a tissue acoustic attenuation function and a tissue conductivity compensation factor are established. The tissue conductivity compensation factor is used to correct the attenuation coefficient of the tissue acoustic attenuation function at the multilayer tissue interface. The sound field distribution function is convolved with the tissue sound attenuation function corrected by the tissue conductivity compensation factor to generate the sound field tissue action model. The sound field tissue action model is used to characterize the sound pressure attenuation gradient distribution and thermal deposition distribution under the combined effect of the skin tissue thickness and the skin surface impedance.

[0008] Furthermore, the step of generating dynamic focus control commands based on the sound field organization model includes: Extract the sound pressure attenuation gradient distribution from the sound field organization model; The spatial location point corresponding to the maximum sound pressure value in the sound pressure attenuation gradient distribution is determined as the dynamic focal point; Generate the dynamic focus control command containing the coordinates of the dynamic focus position.

[0009] Furthermore, the real-time acquisition of temperature feedback signals and displacement feedback signals of the medicated plaster patch's effective area includes: Thermocouple arrays embedded in the ultrasonic transducer are used to collect temperature feedback signals from multiple spatial sampling points in the action area of ​​the plaster patch in real time at a preset sampling frequency, and the temperature feedback signals are then processed by median filtering. The ultrasonic transducer emits detection ultrasonic waves and receives the echo signal reflected from the area of ​​the plaster patch. The echo signal is orthogonally demodulated, the phase change is extracted, and the displacement feedback signal is calculated based on the phase change. The displacement feedback signal and the temperature feedback signal are correlated point by point on the time axis to generate a spatiotemporally synchronized feedback dataset.

[0010] Further, the step of updating the dynamic focusing control command based on the temperature feedback signal and the displacement feedback signal, and driving the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command, includes: The temperature feedback signal is compared with a preset safe temperature threshold. When the temperature feedback signal exceeds the safe temperature threshold, a power reduction correction parameter is generated; The displacement feedback signal is compared with a preset steady-state displacement threshold. When the fluctuation amplitude of the displacement feedback signal exceeds the steady-state displacement threshold, focus repositioning correction parameters are generated; Based on the power reduction correction parameter and the focus repositioning correction parameter, the dynamic focus control command is updated to obtain the updated dynamic focus control command.

[0011] Further, after updating the dynamic focus control command based on the power reduction correction parameter and the focus repositioning correction parameter to obtain the updated dynamic focus control command, the method further includes: The remaining drug content of the plaster patch is obtained by detecting the change in drug concentration of the plaster patch using an electrochemical sensor installed on the plaster patch; When the remaining drug content is lower than a preset drug threshold, a termination control command is generated, and the ultrasonic transducer is stopped from being driven according to the termination control command. At the same time, a drug administration completion prompt signal is generated. When the remaining drug content is higher than or equal to the preset drug threshold, and the temperature feedback signal and the displacement feedback signal are both within the steady-state threshold range for multiple consecutive sampling periods, an operation command to maintain the current dynamic focus control command is generated.

[0012] Further, driving the ultrasonic transducer to emit focused ultrasonic signals toward the plaster patch includes: Based on the dynamic focusing control command, extract the focal spatial coordinates and the desired sound pressure amplitude; Based on the focal space coordinates, the phase delay time of each array element in the ultrasonic transducer is calculated using a reverse time offset algorithm; Based on the desired sound pressure amplitude and the sound field organization model, the excitation voltage amplitude of each element in the ultrasonic transducer is calculated, and the excitation voltage amplitude is subjected to aperture weighting to suppress sidelobes. Based on the calculated phase delay time and the excitation voltage amplitude after aperture weighting, the ultrasonic transducer is controlled to emit the focused ultrasonic signal.

[0013] Furthermore, before acquiring the initial operating parameters of the ultrasonic transducer and the real-time physiological characteristic data of the subject to be drugged, the procedure further includes: In response to a drug administration initiation command sent by a mobile terminal, an electrical performance self-test and a communication link self-test are performed on the ultrasonic transducer. The electrical performance self-test includes detecting the impedance matching status of each array element in the ultrasonic transducer, and the communication link self-test includes detecting the wireless signal strength with the mobile terminal. When both the electrical performance self-test result and the communication link self-test result are normal, the steps of obtaining the initial working parameters of the ultrasonic transducer and obtaining the real-time physiological characteristic data of the subject to be drugged are executed. When the electrical performance self-test result or the communication link self-test result is abnormal, a fault prompt signal is generated and sent to the mobile terminal.

[0014] In a second aspect of the invention, an ultrasonic-excited medicated plaster patch drug delivery control system is provided, comprising: The acquisition module is used to acquire the initial operating parameters of the ultrasonic transducer and to acquire the real-time physiological characteristic data of the subject to be drugged. The construction module is used to construct a sound field organization and action model based on the initial working parameters and the real-time physiological characteristic data; The generation module is used to generate dynamic focus control commands based on the sound field organization model. The excitation module is used to drive the ultrasonic transducer to emit focused ultrasonic signals toward the plaster patch according to the dynamic focusing control command, so as to excite the plaster patch to release the drug. The acquisition module is used to acquire temperature feedback signals and displacement feedback signals of the medicated patch's effective area in real time; The update module is used to update the dynamic focusing control command according to the temperature feedback signal and the displacement feedback signal, and drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

[0015] The embodiments of the present invention have at least the following beneficial effects: 1. By acquiring the initial working parameters of the ultrasonic transducer and the real-time physiological characteristics of the subject to be drugged, a sound field tissue action model is constructed. This model can adaptively adjust the sound field distribution according to the individual skin tissue thickness and impedance differences, thereby achieving precise focusing and dynamic optimization of ultrasonic energy. This effectively solves the technical problems in the existing technology, such as uneven sound energy distribution and low transdermal efficiency caused by ignoring individual physiological differences, and significantly improves the accuracy and adaptability of drug delivery.

[0016] 2. By collecting temperature and displacement feedback signals from the medicated patch's application area in real time and dynamically comparing them with preset safety thresholds, power reduction correction parameters or focus repositioning correction parameters can be generated in a timely manner, forming a closed-loop feedback control mechanism. This effectively solves the technical problems of lacking real-time safety monitoring and having the risk of local overheating or tissue damage in existing technologies, maintaining a stable therapeutic effect while ensuring the safety of drug administration.

[0017] 3. By detecting the remaining drug content of the medicated plaster and combining the steady-state characteristics of temperature and displacement feedback signals, the system intelligently generates termination control commands or maintains the current operation commands, realizing automated judgment and precise control of the drug administration process. This effectively solves the technical problem in existing technologies that cannot intelligently control the drug administration process based on the drug release state, leading to insufficient or excessive drug administration, and improves the integrity of drug administration and treatment efficiency. Attached Figure Description

[0018] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the invention are illustrated in the drawings by way of example and not limitation, wherein: Figure 1 This is a schematic flowchart of an ultrasonic-stimulated plaster patch drug delivery control method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a plaster patch structure provided in an embodiment of the present invention; Figure 3This is a schematic diagram of the ultrasonic-excited plaster patch drug delivery control system provided in an embodiment of the present invention. Detailed Implementation

[0019] The principles and spirit of the invention will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are provided merely to enable those skilled in the art to better understand and implement the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided to make the invention more thorough and complete, and to fully convey the scope of the invention to those skilled in the art.

[0020] The following is for reference. Figure 1 , Figure 1 This is a schematic flowchart illustrating a method for controlling drug delivery using an ultrasonically stimulated medicated plaster patch according to an embodiment of the present invention. Figure 1 As shown, a method for controlling drug delivery using an ultrasonically stimulated medicated plaster patch includes: S1: Obtain the initial operating parameters of the ultrasonic transducer and acquire real-time physiological characteristic data of the subject to be drugged.

[0021] The plaster patch of this application is a transdermal drug delivery formulation containing a drug reservoir and an acoustic release layer. When stimulated by focused ultrasound, the acoustic release layer undergoes structural changes or increased permeability, thereby promoting the release of the drug from the reservoir and its entry into the body through the skin.

[0022] like Figure 2 As shown, the backing layer 1 is made of a flexible polymer film material, serving as the supporting substrate for the overall structure. The drug reservoir 2, located below the backing layer 1, contains a therapeutic dose of active drug. An electrochemical sensor 5 is integrated inside or at its contact surface to monitor drug concentration changes in real time. The acoustic release layer 3, located below the drug reservoir 2, is composed of an acoustic polymer containing microbubbles or phase change materials. Under focused ultrasound signal excitation, it can form micropores to control the controlled release of the drug. The adhesive layer 4, located below the acoustic release layer 3, is used to tightly adhere the plaster to the skin surface of the recipient, ensuring effective transmission of ultrasound energy. The electrochemical sensor 5 contacts the drug reservoir 2 via a screen-printed electrode, and its output signal is used to calculate the remaining drug content, providing a basis for intelligent termination of the drug delivery process. This plaster is used in conjunction with an ultrasonic transducer; focused ultrasound is transmitted through the skin to the acoustic release layer 3, triggering the on-demand release of drug from the reservoir.

[0023] An ultrasonic transducer is a device used to transmit focused ultrasound signals. In this application, a phased array ultrasonic transducer is used, which contains multiple independently controlled array elements. By adjusting the phase and amplitude of each array element, the sound beam can be focused and scanned. The recipient of the drug refers to a patient using the medicated plaster patch. The method of this application dynamically adjusts the ultrasound parameters according to the individual physiological differences of the patient to improve the safety and effectiveness of drug administration.

[0024] The initial operating parameters of an ultrasonic transducer refer to the basic configuration data pre-stored in the control system's memory. This data is preset based on the hardware characteristics of the ultrasonic transducer and typical usage scenarios. Specifically, the center frequency, initial sound pressure level, initial focusing focal spot size, and pulse repetition frequency of the ultrasonic transducer are obtained by reading the configuration file in the non-volatile memory.

[0025] More specifically, the center frequency refers to the fundamental frequency at which the ultrasound transducer emits ultrasound waves, for example, set to 1 MHz. The frequency determines the penetration depth and resolution of the ultrasound waves in the tissue. The initial sound pressure amplitude refers to the initial set value of the pressure amplitude of the sound waves emitted by the ultrasound transducer, for example, set to 0.5 MPa. This parameter directly affects the drug release rate.

[0026] The initial focusing focal point size refers to the spatial size of the focal region of the focused sound beam emitted by the ultrasonic transducer, such as an ellipsoid of 2mm × 2mm × 3mm. This parameter determines the range of drug release. The pulse repetition frequency refers to the number of ultrasonic pulses emitted per second by the ultrasonic transducer, such as 100Hz. This parameter affects the temporal distribution of ultrasonic energy.

[0027] Real-time physiological characteristic data of the subject to be treated is acquired. Real-time physiological characteristic data refers to dynamic parameters reflecting the current physiological state of the subject, including skin surface temperature, skin tissue thickness, and skin surface impedance. Skin surface temperature is collected by an infrared sensor, which is a non-contact temperature detection element that converts the infrared energy radiated by the skin into a temperature value, for example, with an accuracy of ±0.1℃.

[0028] Skin tissue thickness was acquired using ultrasonic echo ranging. An ultrasonic transducer emits a detection ultrasound beam, which generates a reflected echo at the interface between the skin surface and subcutaneous tissue. By measuring the time difference between the emitted and received echoes and considering the propagation speed of the ultrasound in the tissue, the skin tissue thickness was calculated. Skin surface impedance was acquired using an impedance measurement unit employing a four-electrode method. A weak alternating current was applied to the skin surface, and the voltage drop was measured to calculate the impedance value. This value reflects the skin's water content and stratum corneum condition, indirectly affecting the transdermal drug penetration efficiency.

[0029] S11: Read the pre-stored center frequency, initial sound pressure amplitude, initial focus size, and pulse repetition frequency of the ultrasonic transducer as initial operating parameters.

[0030] Pre-stored configuration data is stored in the control system's non-volatile memory, such as EEPROM or flash memory. The center frequency is determined based on the ultrasonic transducer design; for example, for transdermal drug delivery, a frequency between 0.5 MHz and 3 MHz is typically chosen. The initial sound pressure level (SPL) amplitude is set according to the acoustic sensitivity of the patch; for example, for patches containing microbubbles, the initial SPL amplitude is set to 0.2 MPa to 1.0 MPa. The initial focus size is related to the transducer's aperture and focal length; for example, a transducer with a focal length of 30 mm has a focus size of approximately 3 mm. The pulse repetition frequency is set to ensure sufficient energy output while avoiding heat buildup; for example, it is set to 50 Hz to 200 Hz. These parameters are loaded from memory into the working memory during system initialization.

[0031] S12: The skin surface temperature of the subject to be administered is collected by an infrared sensor, the skin tissue thickness of the subject to be administered is collected by an ultrasonic echo ranging method, and the skin surface impedance value of the subject to be administered is collected by an impedance measurement unit. The skin surface temperature, skin tissue thickness and skin surface impedance value are used as real-time physiological characteristic data.

[0032] Infrared sensors employ thermopile or pyroelectric sensors, with their measurement window aligned with the skin area surrounding the medicated plaster. By measuring the intensity of infrared radiation emitted by the skin, the skin surface temperature is calculated using Planck's law of radiation. Ultrasonic echo ranging utilizes the same ultrasonic transducer to emit short-pulse ultrasonic waves, such as pulses with a pulse width of 1 microsecond. These pulses generate reflected echoes at the interface between the skin surface and the subcutaneous fat layer. A high-speed analog-to-digital converter acquires the echo signals, and the time difference between transmission and reception is calculated. Skin tissue thickness Where c is the speed of sound, taken as 1540 m / s. The impedance measurement unit uses electrochemical impedance spectroscopy to apply an AC voltage with a frequency of 10 kHz to 100 kHz to the skin surface, measures the current flowing through the skin, and calculates the impedance value using Ohm's law. This value is usually between several thousand ohms and tens of thousands of ohms, reflecting the barrier function of the stratum corneum of the skin.

[0033] S13: Perform time synchronization alignment on real-time physiological feature data, and compare the aligned real-time physiological feature data with the preset standard physiological parameter range. When the real-time physiological feature data is within the standard physiological parameter range, construct the sound field tissue action model.

[0034] To ensure the accuracy of subsequent modeling, the collected multi-source data is synchronized. Time synchronization alignment refers to matching data from different sensors (infrared sensor, ultrasonic transducer, impedance measurement unit) according to the same time reference. Since the sampling time and sampling frequency of each sensor may be different, the control system uses an interpolation algorithm to resample all data to a unified time axis, for example, using the pulse emission time of the ultrasonic transducer as the synchronization reference. The aligned data is then compared with a preset range of standard physiological parameters.

[0035] The standard physiological parameter ranges are reasonable intervals pre-set based on clinical safety data. For example, the skin surface temperature range is set to 32℃ to 40℃, the skin tissue thickness range is set to 1mm to 8mm, and the skin surface impedance range is set to 1kΩ to 50kΩ. Only when all real-time physiological characteristic data fall within these ranges will the system determine that the subject is suitable for drug administration and continue model construction. If any data exceeds the range, the system will pause operation and issue a prompt to avoid administering the drug under inappropriate physiological conditions.

[0036] In some embodiments, before acquiring the initial operating parameters of the ultrasonic transducer and the real-time physiological characteristic data of the subject to be drugged, the method further includes: In response to a drug administration initiation command sent by a mobile terminal, an electrical performance self-test and a communication link self-test are performed on the ultrasonic transducer. The electrical performance self-test includes detecting the impedance matching status of each array element in the ultrasonic transducer, and the communication link self-test includes detecting the wireless signal strength with the mobile terminal. The drug administration initiation command is sent by the user via a dedicated application on a mobile terminal, such as a smartphone or tablet. The control system receives the command via Bluetooth or WiFi. In response to the command, the control system first performs an electrical performance self-test. Specifically, it measures the impedance value of each array element individually using an impedance analysis circuit and compares it with pre-stored nominal impedance values ​​to determine if there are any short circuits, open circuits, or performance degradation in any array element. Simultaneously, it performs a communication link self-test, detecting the wireless signal strength with the mobile terminal, such as the Received Signal Strength Indicator (RSSI) value, to ensure the reliability of command reception and data transmission.

[0037] When both the electrical performance self-test result and the communication link self-test result are normal, the control system enters S1 and begins to execute the operation of acquiring initial working parameters and real-time physiological characteristic data, thus entering the normal drug administration process.

[0038] When the electrical performance self-test result or the communication link self-test result is abnormal, a fault prompt signal is immediately generated. This signal contains a fault type code and fault description information, which is transmitted wirelessly to the mobile terminal. The specific fault content is displayed on the user interface, prompting the user to check the equipment or contact maintenance.

[0039] S2: Construct a sound field organization model based on initial working parameters and real-time physiological characteristic data.

[0040] The acoustic field tissue interaction model is a mathematical model used to describe the changes in energy distribution and the resulting thermal effects of focused ultrasound as it penetrates the skin and tissue layers. This model integrates the acoustic field distribution characteristics of ultrasound with the tissue's attenuation properties. The acoustic field distribution is determined by the initial operating parameters of the ultrasound transducer, while the tissue's attenuation characteristics are determined by real-time physiological data. This model allows for the prediction of the deposition location and intensity of focused ultrasound energy in tissues under specific physiological conditions.

[0041] S21: Based on the initial sound pressure amplitude, initial focus size, and pulse repetition frequency in the initial working parameters, establish a sound field distribution function that includes spatial sound pressure distribution and time duty cycle.

[0042] In constructing the acoustic field organization model, this step first establishes the acoustic field distribution function. The acoustic field distribution function describes the sound pressure distribution generated by the ultrasonic transducer in space. For a phased array transducer, its acoustic field distribution function is established based on Rayleigh integrals. Assume the ultrasonic transducer contains N array elements, and the position coordinates of the i-th element are... The amplitude of its excitation signal is Phase delay is Then the sound pressure P(x,y,z) at any point (x,y,z) in space can be expressed as the superposition of the contributions of each array element:

[0043] in, Let be the density of the medium, and c be the speed of sound. Angular frequency and f is the center frequency, and k is the wave number. , Let be the distance from the i-th element to the point (x, y, z) and , The directional factor of the array element. The radiation angle.

[0044] Duty cycle is determined by the pulse repetition frequency (PRF) and the pulse width. Decide: .

[0045] The time duty cycle affects the total energy deposited per unit time. In the sound field distribution function, the equivalent continuous sound pressure is obtained by multiplying the instantaneous sound pressure by the time duty cycle. In this application, the sound field distribution function is implemented using a sound field simulation library written in MATLAB or C++, which calculates the superposition of contributions from each array element based on Huygens' principle.

[0046] S22: Based on the skin tissue thickness and skin surface impedance values ​​in real-time physiological characteristic data, establish a tissue acoustic attenuation function and a tissue conductivity compensation factor. The tissue conductivity compensation factor is used to correct the attenuation coefficient of the tissue acoustic attenuation function at the multi-layer tissue interface.

[0047] This step establishes the tissue acoustic attenuation function, which describes the energy attenuation characteristics of ultrasound waves propagating through the skin and subcutaneous tissue. The basic form of the tissue acoustic attenuation function is:

[0048] in, This is the initial sound pressure level. For transmission distance, This is the attenuation coefficient related to the frequency f. The attenuation coefficient is related to tissue type; for skin tissue, ... ,in The attenuation rate is typically taken as 0.5 dB / (MHz·cm).

[0049] To achieve more accurate modeling, this step introduces a tissue conductivity compensation factor, which is a correction coefficient calculated based on the skin surface impedance value. The principle behind this factor is that skin impedance is closely related to the water content of the stratum corneum, and the water content affects the acoustic attenuation characteristics of the tissue.

[0050] Establish the impedance value R and the attenuation coefficient correction amount Mapping relationship:

[0051] Where k is the proportionality coefficient determined through experiments. Using the reference impedance value, the corrected attenuation coefficient is then: The corrected tissue acoustic attenuation function is:

[0052] Tissue conductivity compensation factor refers to the correction amount. This is used to correct the attenuation coefficient of the tissue acoustic attenuation function at the interface of multiple tissues, so that the acoustic attenuation model can better reflect the differences in individual skin.

[0053] S23: Convolve the sound field distribution function with the tissue sound attenuation function corrected by the tissue conductivity compensation factor to generate a sound field tissue interaction model. The sound field tissue interaction model is used to characterize the sound pressure attenuation gradient distribution and thermal deposition distribution under the combined effect of skin tissue thickness and skin surface impedance.

[0054] The sound field distribution function and the tissue sound attenuation function are fused. Sound field tissue effect model. We obtain the following by performing convolution operations in the spatial domain:

[0055] Where P is the sound field distribution function, and A' is the tissue sound attenuation function corrected for compensation factors. This model not only includes the sound pressure attenuation gradient distribution but also calculates the thermal deposition distribution using a thermal deposition formula. Thermal deposition Defined as:

[0056] in, The relationship between sound intensity and sound pressure is: , For tissue density, The specific heat capacity of the tissue. The sound pressure attenuation gradient distribution refers to the gradient field in model M where the sound pressure amplitude varies with spatial location, obtained by calculating the partial derivatives of M in three directions: .

[0057] Gradient distribution is used to determine the location of the maximum sound pressure level. Thermal deposition distribution is used to assess the safety of tissue temperature rise. This model is implemented numerically in an embedded system, using the finite difference method to discretize the continuous space into grid points, and performing discretized convolution calculations at each grid point.

[0058] S3: Generate dynamic focus control commands based on the sound field organization model.

[0059] After obtaining the acoustic field organization model, specific control commands are generated based on this model. The dynamic focusing control command is a set of digital commands used to control the phase and amplitude of each element of the ultrasonic transducer. Its core content is the dynamic focal point position coordinates. The dynamic focal point position refers to the spatial point where the focused ultrasonic energy is most concentrated. This position is not fixed but is adjusted in real time according to the distribution of the sound pressure attenuation gradient in the acoustic field organization model.

[0060] Because human tissue is not a homogeneous medium, sound waves undergo refraction, reflection, and attenuation during propagation, causing the point of maximum energy deposition to shift from the geometric focal point. By extracting the sound pressure attenuation gradient distribution in the model, the spatial location point corresponding to the maximum sound pressure is found, and this point is used as the dynamic focal point, thereby ensuring that the focused ultrasound energy is always aligned with the optimal release area of ​​the medicated plaster patch.

[0061] S31: Extract the sound pressure attenuation gradient distribution in the sound field organization model.

[0062] When generating dynamic focus control commands, this step first extracts the sound pressure attenuation gradient distribution from the sound field organization model. The sound pressure attenuation gradient distribution refers to the gradient field where the sound pressure amplitude varies with spatial location. For the discretized model... ,in For grid indexing, the gradient is approximated using finite difference:

[0063]

[0064]

[0065] in, The grid spacing is [value]. The sound pressure attenuation gradient distribution reflects the drastic change in sound field energy; regions with larger gradients typically correspond to focal edges.

[0066] S32: Determine the spatial location point corresponding to the maximum sound pressure value in the sound pressure attenuation gradient distribution, and use it as the dynamic focal point.

[0067] This step involves finding the global maximum value of the sound pressure amplitude within the sound pressure attenuation gradient distribution. This is done by traversing the computational grid points in the model and comparing the sound pressure values ​​at each point. Find the coordinates of the maximum value point. .

[0068] Since the point of maximum sound pressure level is usually located in the core region of the focused sound beam, using this point as the dynamic focal point ensures that the ultrasonic energy is most concentrated on the acoustic layer of the plaster. In practical applications, to avoid local noise interference, Gaussian smoothing can be performed first, followed by finding the maximum value, or the centroid algorithm can be used to calculate the centroid position of the focal region. Gaussian smoothing uses a three-dimensional Gaussian kernel for convolution, and the centroid calculation formula is:

[0069]

[0070] .

[0071] S33: Generates dynamic focus control instructions containing dynamic focus position coordinates.

[0072] The dynamic focus control command is a data packet containing a command type identifier and focus coordinates. And a timestamp. The command is sent to the drive control module of the ultrasonic transducer, which calculates the phase delay of each array element in real time based on the focal coordinates. For a planar phased array, the focal coordinates are... When, the i-th array element (coordinates are...) The phase delay of ) is:

[0073] Where f is the center frequency and c is the speed of sound. This phase delay ensures that the sound waves emitted by each array element arrive at the focal point simultaneously.

[0074] S4: According to the dynamic focusing control command, drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch to stimulate the plaster patch to release the drug.

[0075] After receiving a dynamic focusing control command, the ultrasonic transducer calculates the required phase delay time and excitation voltage amplitude for each array element based on the focal space coordinates and desired sound pressure amplitude contained in the command. Then, it drives the array elements to emit ultrasonic signals through a high-voltage pulse generation circuit. The ultrasonic signals emitted by each array element are spatially superimposed to form a focused sound beam. The energy of this sound beam is concentrated at the dynamic focal position and acts on the acoustic release layer of the plaster patch.

[0076] The acoustic release layer is typically composed of polymers containing microbubbles or phase change materials. Under the cavitation and mechanical effects of ultrasound, the microbubbles oscillate or rupture, resulting in micropores in the release layer, allowing drug molecules in the drug reservoir to pass through and enter the skin. The energy parameters of the focused ultrasound signal are precisely controlled according to dynamic focusing commands to ensure a stable drug release rate without causing tissue damage.

[0077] S5: Real-time acquisition of temperature and displacement feedback signals from the area of ​​action of the medicated plaster patch.

[0078] During ultrasound emission, physiological feedback information of the medicated patch's target area is monitored in real time. The temperature feedback signal reflects the thermal effect of ultrasound energy deposition in the tissue, while the displacement feedback signal reflects the mechanical response of the tissue under the action of ultrasound radiation force.

[0079] Temperature feedback signals are acquired via a thermocouple array embedded in the ultrasonic transducer. This array consists of multiple micro-thermocouple sensors, such as K-type thermocouples, with their thermal junctions exposed on the transducer surface, allowing direct or close-range sensing of the skin's temperature distribution. Displacement feedback signals are obtained by the ultrasonic transducer emitting and receiving ultrasound waves. Utilizing the principle of ultrasonic elastography, the minute displacement of tissue under acoustic radiation force can be calculated by analyzing the phase change of the echo signal. This displacement reflects changes in the tissue's mechanical properties and indirectly indicates the drug release process. The specific implementation of these acquisition methods will be detailed in subsequent subordinate steps.

[0080] S51: Thermocouple array embedded in the ultrasonic transducer is used to collect temperature feedback signals from multiple spatial sampling points in the medicated patch application area in real time at a preset sampling frequency, and the temperature feedback signals are processed by median filtering.

[0081] Thermocouple array consists of multiple miniature thermocouples embedded in a specific geometric layout on the surface of an ultrasonic transducer, such as an 8×8 grid array, with the coverage area corresponding to the area of ​​action of the plaster patch.

[0082] Each thermocouple is connected to an analog-to-digital converter via a multiplexer, and is cyclically sampled at a preset sampling frequency, such as 50Hz. Since the thermocouple outputs a millivolt-level voltage signal, it needs to be amplified by a high-precision amplifier before analog-to-digital conversion. The temperature feedback signal undergoes median filtering; specifically, for each sampling point, the median of five consecutive sample values ​​is taken as the current temperature value for that point to eliminate impulse noise and occasional interference.

[0083] S52: The ultrasonic transducer emits detection ultrasonic waves and receives the echo signal reflected from the area of ​​the plaster patch. The echo signal is orthogonally demodulated, the phase change is extracted, and the displacement feedback signal is calculated based on the phase change.

[0084] During the intervals between focused ultrasound transmissions, the ultrasonic transducer emits short pulses to detect ultrasound waves, such as pulses with the same frequency but smaller amplitude as the focused ultrasound. The echo signal is received by the transducer, pre-amplified, and converted from analog to digital before being sent to a digital signal processor. The echo signal undergoes quadrature demodulation, i.e., it is modulated with the in-phase carrier wave. and orthogonal carriers After multiplication and low-pass filtering, the I and Q signals are obtained. Let the reference echo signal be... The current echo signal is The phase change is extracted by comparing the I and Q components of the two. :

[0085] Based on the relationship between phase change and displacement, the displacement d is:

[0086] in, This refers to the wavelength of ultrasound. c is the speed of sound. The center frequency of the ultrasound was detected. This displacement reflects the mechanical response of the medicated patch's effective area and is related to the drug release process.

[0087] S53: Correlate the displacement feedback signal and the temperature feedback signal point by point on the time axis to generate a spatiotemporally synchronized feedback dataset.

[0088] This step fuses the two feedback signals. Since the displacement feedback signal and the temperature feedback signal come from different sampling channels and may be sampled at different times, the control system uses linear interpolation to resample the displacement signal onto the time axis of the temperature signal, so that the temperature value at each moment has a corresponding displacement value.

[0089] Let the sampling time of the temperature signal be... The sampling time of the displacement signal is For a given Find two adjacent displacement sampling points and Interpolation yields the displacement value:

[0090] The spatiotemporal synchronization feedback dataset is a two-dimensional array. The first dimension represents time points, and the second dimension represents spatial sampling points. Each element contains the temperature and displacement values ​​of that spatial point at that moment. This dataset serves as the input to closed-loop control, enabling the control system to simultaneously monitor changes in thermal and mechanical effects.

[0091] S6: Based on the temperature feedback signal and displacement feedback signal, update the dynamic focusing control command, and drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

[0092] During ultrasound emission, the initially set focusing parameters may no longer be optimal due to tissue absorption of ultrasound, heat conduction, and changes in tissue state after drug release. Based on real-time acquired temperature and displacement feedback signals, the dynamic focusing control command is dynamically adjusted.

[0093] Specifically, when the temperature feedback signal indicates that the local temperature is too high, it means that the ultrasound energy input is too large and the output power needs to be reduced; when the displacement feedback signal indicates that the tissue displacement fluctuation is too large, it means that the focal position may have deviated from the target area and the focal point needs to be repositioned. The updated dynamic focusing control command is used again to drive the ultrasound transducer, thereby ensuring that the ultrasound parameters are always in a safe and efficient state throughout the entire drug delivery process.

[0094] S61: Compare the temperature feedback signal with the preset safe temperature threshold.

[0095] Safe temperature threshold This value is preset according to tissue thermal damage safety standards, for example, set to 42℃. Temperatures below this level will not cause irreversible damage to skin tissue. The current temperature feedback signal value is read. With the safe temperature threshold Perform numerical comparisons.

[0096] S62: When the temperature feedback signal exceeds the safe temperature threshold, generate power reduction correction parameters.

[0097] If the temperature feedback signal value greater than the safe temperature threshold This indicates that the current ultrasound energy input is too high, which may lead to tissue overheating. At this point, the system generates power reduction correction parameters. ,For example The value is between 0 and 1, indicating that the current power will be reduced to half of the original power. The power reduction correction parameters will be used in subsequent instruction updates.

[0098] S63: Compare the displacement feedback signal with the preset steady-state displacement threshold.

[0099] Steady-state displacement threshold This is a preset value based on the fluctuation range of tissue displacement during normal drug administration, for example, set to 2 micrometers. The control system reads the displacement feedback signal at the current moment. , and steady-state displacement threshold Numerical comparisons are performed. Simultaneously, the displacement fluctuation amplitude is calculated, defined as the difference between the maximum and minimum displacement values ​​over multiple consecutive sampling periods.

[0100] in This is the length of the sliding window.

[0101] S64: When the fluctuation amplitude of the displacement feedback signal exceeds the steady-state displacement threshold, generate focus repositioning correction parameters.

[0102] If the fluctuation amplitude of the displacement feedback signal Greater than the steady-state displacement threshold This indicates that the focal position may have shifted, leading to an unstable distribution of radiation force on the tissue. At this point, the system generates a focal repositioning correction parameter, which is the focal offset vector. The determination of the focus repositioning correction parameters can be achieved by analyzing the oscillation characteristics of the displacement signal and the sensitivity of the acoustic field model, for example, by using the gradient descent method to adjust the focus position along the displacement gradient direction.

[0103] S65: Update the dynamic focus control command based on the power reduction correction parameter and the focus repositioning correction parameter to obtain the updated dynamic focus control command.

[0104] If power reduction correction parameters are generated The expected sound pressure amplitude in the new instruction If focus repositioning correction parameters are generated. The focus coordinates in the new instruction are then updated as follows: .

[0105] The updated dynamic focus control commands include adjusted focus position and power settings, which will be used for the next cycle of ultrasonic emission.

[0106] Furthermore, driving the ultrasonic transducer to emit focused ultrasonic signals toward the plaster patch includes: During ultrasonic emission, specific drive control is performed according to dynamic focusing control commands. These commands contain the focal space coordinates and the desired sound pressure level, which are parsed from the command packet by the drive control module and used as input parameters for subsequent calculations.

[0107] First, based on the focal spatial coordinates, the phase delay time of each element in the ultrasonic transducer is calculated using the inverse time migration algorithm. The inverse time migration algorithm is a beam focusing method based on wave equation inversion. Its basic principle is: assuming a sound wave is emitted from the focal point, the time it takes for the sound wave to propagate to each element is calculated, and this time is taken as the delay time of the emitted sound wave from each element. For the i-th element in the phased array transducer, its spatial coordinates are... The focal coordinates are Then the distance from the array element to the focus is The delay time is c, where c is the speed of sound. In practical applications, the maximum delay time is usually used as the reference, and the emission time of each array element is delayed relative to the reference. This ensures that the sound waves emitted by all array elements reach the focal point simultaneously.

[0108] Based on the desired sound pressure level amplitude and sound field organization model, the excitation voltage amplitude of each element in the ultrasonic transducer is calculated, and the excitation voltage amplitude is subjected to aperture weighting to suppress sidelobes. Desired sound pressure level amplitude. The target is to control the sound field, but the amplitudes of each element are not the same because the sound field organization model reflects the attenuation characteristics of the organization, and compensation needs to be made according to the model. Let the sound pressure amplitude at the focal point of the sound field organization model be... With the excitation voltage amplitude of each array element The relationship is a linear system:

[0109] in Let be the transfer function from the i-th element to the focus. By solving this system of linear equations, the required excitation voltage amplitude for each element can be derived. Subsequently, the excitation voltage amplitude is subjected to aperture weighting, for example, using a Hamming window function for weighting: ,in

[0110] This results in the edge elements having a lower amplitude compared to the center elements, thereby suppressing the sidelobe energy of the sound beam and reducing sound radiation in non-target areas.

[0111] Based on the calculated phase delay time and the aperture-weighted excitation voltage amplitude, the ultrasonic transducer is controlled to emit a focused ultrasonic signal. The drive control module sets the delay counters for each channel of the high-voltage pulse generation circuit according to the phase delay time of each array element; and sets the high-voltage power supply voltage or pulse width (for pulse width modulation) for each channel according to the aperture-weighted excitation voltage amplitude. Once all parameters are set, the pulse generation circuit is triggered, simultaneously driving all array elements to emit ultrasonic pulses. These pulses are spatially superimposed to form a focused ultrasonic signal focused at the dynamic focal point.

[0112] Further, after updating the dynamic focus control command based on the power reduction correction parameter and the focus repositioning correction parameter to obtain the updated dynamic focus control command, the method further includes: S71: Obtain the remaining drug content of the plaster patch. The remaining drug content is obtained by detecting the change in drug concentration of the plaster patch using an electrochemical sensor installed on the plaster patch.

[0113] Electrochemical sensors are integrated into medicated plaster patches, for example, using screen-printed electrodes whose surfaces are modified with electrochemically active materials sensitive to specific drug molecules. When the drug is released from its reservoir, the drug molecules react with the electrode surface, generating a current signal proportional to the drug concentration. Let the initial total amount of drug be... The sensor calibration coefficient is The remaining drug content for:

[0114] The control system reads this current signal and, in conjunction with the initial total drug amount, calculates the current remaining drug content, for example, expressed as a percentage.

[0115] S72: When the remaining drug content is lower than the preset drug threshold, a termination control command is generated, and the ultrasonic transducer is stopped according to the termination control command. At the same time, a drug administration completion prompt signal is generated.

[0116] Preset drug threshold For example, it can be set to 5% of the initial total drug amount, when the remaining drug content... When the drug level falls below this threshold, it indicates that the drug has been largely released, and continued ultrasound stimulation is meaningless and may cause unnecessary tissue exposure. At this point, the control system generates a termination control command, which is sent to the drive circuit of the ultrasound transducer to shut off the high-voltage power output and stop ultrasound emission. Simultaneously, a drug administration completion notification signal is generated, which can be sent to the user's mobile terminal, such as a smartphone, via Bluetooth or WiFi to notify the user that the drug administration process has ended.

[0117] S73: When the remaining drug content is higher than or equal to the preset drug threshold, and the temperature feedback signal and displacement feedback signal are within the steady-state threshold range for multiple consecutive sampling cycles, an operation command to maintain the current dynamic focus control command is generated.

[0118] If the remaining drug content has not yet reached the termination threshold, i.e. ≥ Furthermore, the temperature and displacement feedback signals did not trigger the correction condition within multiple consecutive sampling periods (e.g., 10 consecutive sampling periods), i.e. and This indicates that the current drug delivery process is in a stable state. At this point, the system generates an operation instruction to maintain the current dynamic focusing control command. This instruction tells the control system to continue using the current command parameters without making any corrections, in order to maintain the stability of the drug delivery process.

[0119] The embodiments of the present invention have at least the following beneficial effects: 1. By acquiring the initial working parameters of the ultrasonic transducer and the real-time physiological characteristics of the subject to be drugged, a sound field tissue action model is constructed. This model can adaptively adjust the sound field distribution according to the individual skin tissue thickness and impedance differences, thereby achieving precise focusing and dynamic optimization of ultrasonic energy. This effectively solves the technical problems in the existing technology, such as uneven sound energy distribution and low transdermal efficiency caused by ignoring individual physiological differences, and significantly improves the accuracy and adaptability of drug delivery.

[0120] 2. By collecting temperature and displacement feedback signals from the medicated patch's application area in real time and dynamically comparing them with preset safety thresholds, power reduction correction parameters or focus repositioning correction parameters can be generated in a timely manner, forming a closed-loop feedback control mechanism. This effectively solves the technical problems of lacking real-time safety monitoring and having the risk of local overheating or tissue damage in existing technologies, maintaining a stable therapeutic effect while ensuring the safety of drug administration.

[0121] 3. By detecting the remaining drug content of the medicated plaster and combining the steady-state characteristics of temperature and displacement feedback signals, the system intelligently generates termination control commands or maintains the current operation commands, realizing automated judgment and precise control of the drug administration process. This effectively solves the technical problem in existing technologies that cannot intelligently control the drug administration process based on the drug release state, leading to insufficient or excessive drug administration, and improves the integrity of drug administration and treatment efficiency.

[0122] like Figure 3 As shown in some embodiments, an ultrasonic-excited medicated plaster patch drug delivery control system includes: The acquisition module 301 is used to acquire the initial operating parameters of the ultrasonic transducer and to acquire the real-time physiological characteristic data of the subject to be drugged. Construction module 302 is used to construct a sound field organization and action model based on the initial working parameters and the real-time physiological characteristic data; The generation module 303 is used to generate dynamic focusing control commands based on the sound field organization model. The excitation module 304 is used to drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the dynamic focusing control command, so as to excite the plaster patch to release the drug. The acquisition module 305 is used to acquire the temperature feedback signal and displacement feedback signal of the active area of ​​the plaster patch in real time; The update module 306 is used to update the dynamic focusing control command according to the temperature feedback signal and the displacement feedback signal, and drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

[0123] It is understandable that the modules described in this ultrasonic-excited plaster patch drug delivery control system are similar to those in the reference. Figure 1 The steps described in the ultrasonic-induced medicated plaster patch drug delivery control method correspond to each other. Therefore, the operation, characteristics, and beneficial effects described above for the ultrasonic-induced medicated plaster patch drug delivery control method also apply to the ultrasonic-induced medicated plaster patch drug delivery control system and its included modules, and will not be repeated here.

[0124] Furthermore, the storage medium in the embodiments of this application stores program instructions capable of implementing all the above methods. These program instructions can be stored in the storage medium in the form of a software product, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or terminal devices such as computers, servers, mobile phones, and tablets.

[0125] The above description is merely an explanation of some preferred embodiments of the present invention and the technical principles employed. Those skilled in the art should understand that the scope of the invention as described in the embodiments of the present invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present invention.

Claims

1. A method for controlling drug delivery using an ultrasonically stimulated medicated plaster patch, characterized in that, include: The initial operating parameters of the ultrasonic transducer were obtained, and real-time physiological characteristic data of the subjects to be drugged were acquired. Based on the initial working parameters and the real-time physiological characteristic data, a sound field organization and action model is constructed; Based on the sound field organization model, a dynamic focusing control command is generated; According to the dynamic focusing control command, the ultrasonic transducer is driven to emit focused ultrasonic signals toward the plaster patch to stimulate the plaster patch to release the drug. Real-time acquisition of temperature and displacement feedback signals from the area of ​​action of the plaster patch; Based on the temperature feedback signal and the displacement feedback signal, the dynamic focusing control command is updated, and the ultrasonic transducer is driven to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

2. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The acquisition of the initial operating parameters of the ultrasonic transducer and the acquisition of real-time physiological characteristic data of the subject to be drugged include: The center frequency, initial sound pressure amplitude, initial focusing focal point size, and pulse repetition frequency of the pre-stored ultrasonic transducer are read as the initial operating parameters. The skin surface temperature of the subject to be administered the drug is collected by an infrared sensor, the skin tissue thickness of the subject to be administered the drug is collected by an ultrasonic echo ranging method, and the skin surface impedance value of the subject to be administered the drug is collected by an impedance measurement unit. The skin surface temperature, the skin tissue thickness, and the skin surface impedance value are used as the real-time physiological characteristic data. The real-time physiological feature data is time-synchronized and aligned, and the aligned real-time physiological feature data is compared with a preset standard physiological parameter range. When the real-time physiological feature data is within the standard physiological parameter range, a sound field tissue action model is constructed.

3. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The step of constructing a sound field tissue action model based on the initial working parameters and the real-time physiological characteristic data includes: Based on the initial sound pressure amplitude, initial focusing focal size, and pulse repetition frequency in the initial working parameters, a sound field distribution function including spatial sound pressure distribution and time duty cycle is established. Based on the skin tissue thickness and skin surface impedance value in the real-time physiological characteristic data, a tissue acoustic attenuation function and a tissue conductivity compensation factor are established. The tissue conductivity compensation factor is used to correct the attenuation coefficient of the tissue acoustic attenuation function at the multilayer tissue interface. The sound field distribution function is convolved with the tissue sound attenuation function corrected by the tissue conductivity compensation factor to generate the sound field tissue action model. The sound field tissue action model is used to characterize the sound pressure attenuation gradient distribution and thermal deposition distribution under the combined effect of the skin tissue thickness and the skin surface impedance.

4. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The step of generating dynamic focus control commands based on the sound field organization model includes: Extract the sound pressure attenuation gradient distribution from the sound field organization model; The spatial location point corresponding to the maximum sound pressure value in the sound pressure attenuation gradient distribution is determined as the dynamic focal point; Generate the dynamic focus control command containing the coordinates of the dynamic focus position.

5. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The real-time acquisition of temperature feedback signals and displacement feedback signals of the medicated plaster patch's effective area includes: Thermocouple arrays embedded in the ultrasonic transducer are used to collect temperature feedback signals from multiple spatial sampling points in the action area of ​​the plaster patch in real time at a preset sampling frequency, and the temperature feedback signals are then processed by median filtering. The ultrasonic transducer emits detection ultrasonic waves and receives the echo signal reflected from the area of ​​the plaster patch. The echo signal is orthogonally demodulated, the phase change is extracted, and the displacement feedback signal is calculated based on the phase change. The displacement feedback signal and the temperature feedback signal are correlated point by point on the time axis to generate a spatiotemporally synchronized feedback dataset.

6. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The step of updating the dynamic focusing control command based on the temperature feedback signal and the displacement feedback signal, and driving the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command, includes: The temperature feedback signal is compared with a preset safe temperature threshold. When the temperature feedback signal exceeds the safe temperature threshold, a power reduction correction parameter is generated; The displacement feedback signal is compared with a preset steady-state displacement threshold. When the fluctuation amplitude of the displacement feedback signal exceeds the steady-state displacement threshold, focus repositioning correction parameters are generated; Based on the power reduction correction parameter and the focus repositioning correction parameter, the dynamic focus control command is updated to obtain the updated dynamic focus control command.

7. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 6, characterized in that, After updating the dynamic focus control command based on the power reduction correction parameter and the focus repositioning correction parameter to obtain the updated dynamic focus control command, the method further includes: The remaining drug content of the plaster patch is obtained by detecting the change in drug concentration of the plaster patch using an electrochemical sensor installed on the plaster patch; When the remaining drug content is lower than a preset drug threshold, a termination control command is generated, and the ultrasonic transducer is stopped from being driven according to the termination control command. At the same time, a drug administration completion prompt signal is generated. When the remaining drug content is higher than or equal to the preset drug threshold, and the temperature feedback signal and the displacement feedback signal are both within the steady-state threshold range for multiple consecutive sampling periods, an operation command to maintain the current dynamic focus control command is generated.

8. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, The method of driving the ultrasonic transducer to emit focused ultrasonic signals toward the plaster patch includes: Based on the dynamic focusing control command, extract the focal spatial coordinates and the desired sound pressure amplitude; Based on the focal space coordinates, the phase delay time of each array element in the ultrasonic transducer is calculated using a reverse time offset algorithm; Based on the desired sound pressure amplitude and the sound field organization model, the excitation voltage amplitude of each element in the ultrasonic transducer is calculated, and the excitation voltage amplitude is subjected to aperture weighting to suppress sidelobes. Based on the calculated phase delay time and the excitation voltage amplitude after aperture weighting, the ultrasonic transducer is controlled to emit the focused ultrasonic signal.

9. The method for controlling drug delivery using an ultrasonically stimulated plaster patch according to claim 1, characterized in that, Before acquiring the initial operating parameters of the ultrasonic transducer and the real-time physiological characteristic data of the subject to be drugged, the procedure further includes: In response to a drug administration initiation command sent by a mobile terminal, an electrical performance self-test and a communication link self-test are performed on the ultrasonic transducer. The electrical performance self-test includes detecting the impedance matching status of each array element in the ultrasonic transducer, and the communication link self-test includes detecting the wireless signal strength with the mobile terminal. When both the electrical performance self-test result and the communication link self-test result are normal, the steps of obtaining the initial working parameters of the ultrasonic transducer and obtaining the real-time physiological characteristic data of the subject to be drugged are executed. When the electrical performance self-test result or the communication link self-test result is abnormal, a fault prompt signal is generated and sent to the mobile terminal.

10. A control system for the administration of an ultrasonically excited medicated plaster patch, characterized in that, include: The acquisition module is used to acquire the initial operating parameters of the ultrasonic transducer and to acquire the real-time physiological characteristic data of the subject to be drugged. The construction module is used to construct a sound field organization and action model based on the initial working parameters and the real-time physiological characteristic data; The generation module is used to generate dynamic focus control commands based on the sound field organization model. The excitation module is used to drive the ultrasonic transducer to emit focused ultrasonic signals toward the plaster patch according to the dynamic focusing control command, so as to excite the plaster patch to release the drug. The acquisition module is used to acquire temperature feedback signals and displacement feedback signals of the medicated patch's effective area in real time; The update module is used to update the dynamic focusing control command according to the temperature feedback signal and the displacement feedback signal, and drive the ultrasonic transducer to emit focused ultrasonic signals to the plaster patch according to the updated dynamic focusing control command.

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