Intravascular shock wave diagnostic device based on mechanical acoustic impedance feedback and control method thereof

Abstract

The present application relates to a kind of based on mechanical acoustic impedance feedback intravascular shock wave diagnostic device and its control method, belong to vascular intervention medical equipment control technical field, comprising: step S1: emit non-therapeutic micro-mechanical detection wave;Step S2: guide wire proximal end receives the signal of guide wire distal end, utilize time window technology to eliminate the transmission residual wave of guide wire proximal end, extract the acoustic impedance echo signal from guide wire distal end, calculate the actual echo total energy of acoustic impedance echo signal;Step S3: the actual echo total energy of acoustic impedance echo signal is Fourier transformed, to extract feature vector;Step S4: actual echo total energy, high-frequency energy proportion and preset algorithm classification threshold are quantitatively cascaded comparison;Step S5: calculate waveguide transmission attenuation coefficient, automatically adjust driving parameter to compensate loss;The beneficial effects of the present application: using time-sharing multiplexing strategy and introducing waveguide transmission loss compensation model and resonance frequency locking mechanism, precise control treatment is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of vascular interventional medical device control system, and specifically relates to an intravascular shock wave diagnostic device and its control method based on mechanical acoustic impedance feedback. Background Technology

[0002] Vascular calcification is a common complication of cardiovascular disease. Mechanical shockwave guidewire systems are core devices for clinically opening chronic total occlusion (CTO) calcified lesions. They generate high-amplitude mechanical pulses through a main unit, which are transmitted via a metal guidewire to the tip, creating a mechanical impact force that breaks up the calcified plaque. Existing mechanical shockwave guidewire systems (such as the SoundBite technology) employ a "fixed parameter output" open-loop control mode, which has three major technical shortcomings:

[0003] Lack of active environmental awareness: When the guidewire travels in the blood vessel, the contact medium at the tip frequently switches between calcified plaques, the blood vessel wall and blood. Existing equipment cannot sense the type of medium and relies on the doctor's tactile feedback to adjust the operation, which can easily lead to vascular perforation, dissection or ineffective wear of the instrument due to "blind" operation.

[0004] Uncontrollable nonlinear attenuation of energy transmission: When mechanical waves are transmitted in the long guidewire of tortuous blood vessels, energy attenuation occurs due to friction and reflection, and the bending of the guidewire causes the natural frequency to drift. Fixed parameter output will result in "insufficient force" in tortuous blood vessels and "excess energy" in straight blood vessels.

[0005] Frequency domain conflict in diagnosis and treatment: Effective treatment requires low-frequency, long-stroke (e.g., 100Hz, 1mm) mechanical pulses, while medium sensing requires high-frequency, micro-displacement (e.g., 20kHz, 10μm) probe waves. A single driving mechanism cannot simultaneously meet the needs of both frequency domains, causing existing systems to abandon sensing functions.

[0006] However, existing technologies mainly involve the construction of mechanical pulse generators and the structural features of guide wire connection interfaces, but do not address medium identification and adaptive control based on acoustic impedance feedback, thus failing to solve the aforementioned technical problems. Summary of the Invention

[0007] This invention provides a diagnostic device and control method for intravascular shockwave based on mechanical acoustic impedance feedback, which solves the problem of identification and adaptive control of the contact medium (calcified plaque, blood vessel wall, soft tissue and blood) of the metal guidewire tip. It adopts a time-division multiplexing strategy and introduces a waveguide transmission loss compensation model (AGC) and a resonant frequency locking (PLL) mechanism to achieve precise control of treatment.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0009] The intravascular shock wave control method based on mechanical acoustic impedance feedback includes the following steps:

[0010] Step S1: Between treatment pulse cycles, a non-therapeutic micromechanical probe wave is emitted, which propagates from the proximal end of the guidewire to the distal end.

[0011] Step S2: The proximal end of the guidewire receives the signal from the distal end of the guidewire, and the emission aftershock from the proximal end of the guidewire is removed using time window technology. The acoustic impedance echo signal from the distal end of the guidewire is extracted, and the actual total echo energy of the acoustic impedance echo signal is calculated.

[0012] Step S3: Perform a Fourier transform on the actual total echo energy of the acoustic impedance echo signal to extract the feature vector;

[0013] Step S4: Quantitatively compare the actual total echo energy and the proportion of high-frequency energy with the preset algorithm classification threshold;

[0014] Step S5: When executing the treatment mode, the waveguide transmission attenuation coefficient is calculated based on the current actual total echo energy and the reference energy obtained based on the guidewire identity feature data. The driving parameters are automatically adjusted to compensate for the loss, so as to output the energy-corrected treatment pulse.

[0015] Optionally, in step S1, the voice coil motor is locked, and the piezoelectric stack is activated to emit a high-frequency micromechanical probe wave, so that the high-frequency micromechanical probe wave propagates on the guide wire; wherein, the high-frequency micromechanical probe wave is a pulse train with a frequency greater than or equal to 20 kHz.

[0016] Optionally, in step S2, a dynamic force sensor located near the guidewire records the time-domain signal in real time over a period of time from the start of firing. Time-domain signal It integrates the oscillation aftershock signal from near-end emission and the acoustic impedance echo signal reflected back from the far end of the guidewire.

[0017] Furthermore, in step S2, the time window technique involves dividing the time-domain signal... Set a start time and end time , Set to avoid the timing of near-end emission aftershocks, retaining only the time-domain signal. In arrive The signal within the time period is used as the effective acoustic impedance echo signal;

[0018] Specifically, the energy of the extracted effective acoustic impedance echo signal is integrated to calculate the energy value of the current actual acoustic impedance echo signal. The calculation formula is as follows:

[0019] ;

[0020] in, For the sensor in time The collected voltage amplitude is proportional to the mechanical vibration amplitude; Represents instantaneous power; The total energy of the acoustic impedance echo signal or the total energy of the reflected wave is used to determine whether the proximal end of the guidewire has received the acoustic impedance echo signal from the distal end of the guidewire.

[0021] Optionally, in step S3, the Fourier transform is converted into a spectral transform, which is achieved by using signal processing methods to transform the truncated time-domain signal. Execution length is The Fourier transform of the Fourier transform is calculated using the following formula:

[0022] ;

[0023] in, The output is the discrete frequency domain spectrum. It is the frequency point index in the frequency domain. For the first One frequency; The representative took from arrive All items are added together in sequence; The input is a discrete-time signal with a length of . , It is the time-domain sampling point number. ; The total number of sampling points for the signal determines the frequency domain resolution; The imaginary unit; It is a complex exponential basis function, which is essentially a twitch factor and represents sine or cosine basis signals of different frequencies; is the base of the natural logarithm.

[0024] Optionally, in step S3, the extracted feature vector is the high-frequency energy percentage of key quantization indicators calculated from the spectrum. To calculate the cutoff frequency above 10kHz The proportion of high-frequency energy is given by the following formula:

[0025] ;

[0026] in, This represents the proportion of high-frequency energy in the total signal energy, and its value ranges from 0 to 1. For high-frequency energy; Indicates the first Energy at a frequency; The high-frequency boundary frequency index defines the starting position of the high-frequency band; This indicates that due to the conjugate symmetry of the total number of signal sampling points, the effective frequency range is 0- Therefore, the upper limit of the summation is taken as ; This represents the energy value of the actual acoustic impedance echo signal.

[0027] Optionally, in step S4, the actual acoustic impedance echo signal energy value will be calculated. The proportion of high-frequency energy in key quantitative indicators calculated from the spectrum. The comparison is performed against a preset algorithm classification threshold, specifically:

[0028] The quantitative criteria for determining contact with lesions are based on energy judgment criteria:

[0029] This indicates that the total echo energy is higher than the preset effective detection threshold, used to eliminate interference; where, The contact threshold with a hard object;

[0030] Frequency domain judgment criteria: ,in, When the proportion of high-frequency components exceeds a preset ratio, it represents the high-frequency harmonics generated by the head-on collision; among which... This is the threshold for the proportion of high-frequency events;

[0031] The system determined that the preceding medium had high acoustic impedance and a hard texture, confirming it as a calcified lesion.

[0032] The action performed is to unlock the voice coil motor and release a standard therapeutic pulse;

[0033] For contact with blood vessel walls or soft tissues, the quantitative determination criteria are:

[0034] Frequency domain criteria: and Even if the total energy If the proportion of high-frequency signals is below a threshold, it indicates that the high-frequency signals are absorbed by the soft tissue, and this is considered a soft contact; among them, This is the system noise floor threshold or the upper limit of sensor readings under no-load conditions.

[0035] The system determined that the area in front was either a blood vessel wall or a soft plaque.

[0036] The action is to trigger a safety gating system, instantly cutting off high-energy output, or simply maintaining a very low-energy micro-vibration to provide tactile feedback, prompting the user to adjust their position and preventing perforation.

[0037] Optionally, in step S5, the waveguide transmission attenuation coefficient is calculated as follows:

[0038] ;

[0039] in, The waveguide transmission attenuation coefficient or loss rate is a dimensionless or percentage form that represents the proportion of signal wave attenuation during transmission. This represents the ideal echo energy of the guidewire when it is straight. This represents the actual acoustic impedance echo signal energy value; the molecule part This represents the attenuation of the electric field amplitude during signal wave propagation in the waveguide, directly reflecting the magnitude of energy loss; the denominator... It converts absolute attenuation into relative attenuation ratio, which facilitates comparison of loss performance under different waveguide structures and frequencies.

[0040] Optionally, in step S5, adjusting the driving parameters to compensate for losses involves automatically increasing the driving voltage of the next treatment pulse based on the waveguide transmission attenuation coefficient. :

[0041] ;

[0042] in, This refers to the waveguide transmission attenuation coefficient or loss rate. Basic treatment voltage; To compensate for the gain coefficient, the driving voltage of the next treatment pulse is adjusted. This ensures that no matter how tortuous the blood vessel or how much the waveguide transmission attenuation coefficient decreases, the actual mechanical impact power output from the guidewire tip can always effectively break the stone, achieving a constant chisel force output.

[0043] A mechanical acoustic impedance feedback-based intravascular shockwave diagnostic device includes:

[0044] The dual-mode drive unit is configured to alternately output high-energy therapeutic pulse sequences and low-energy diagnostic pulse sequences;

[0045] The acoustic impedance feedback sensing unit, coupled to the output of the dual-mode drive unit, is used to acquire the acoustic impedance echo signal transmitted back through the guide wire.

[0046] The control unit, whose control terminal is connected to the dual-mode drive unit, is used to analyze the characteristics of acoustic impedance echo signals and allow high-energy output when high acoustic impedance characteristics are detected, and suppress high-energy output when low acoustic impedance characteristics are detected.

[0047] The beneficial effects of this invention are:

[0048] This invention utilizes closed-loop adaptive control with acoustic-mechanical dual-mode coupling and adopts a closed-loop control architecture integrating diagnosis and treatment. The system multiplexes the guidewire as a bidirectional signal channel and introduces frequency-domain separated dual-mode waveforms in terms of energy form, realizing a dual closed loop of qualitative identification and quantitative compensation.

[0049] Specifically, in the qualitative dimension (environmental perception), a time-division multiplexing strategy is adopted to emit high-frequency acoustic probe waves during treatment intervals. By utilizing the difference in acoustic impedance between different media (calcifications vs. blood vessel walls), the nature of obstacles in front is determined in real time, thus solving the problem of blind injection.

[0050] In terms of quantitative dimension (constant impact force), by introducing the waveguide transmission loss compensation model (AGC) and the resonant frequency locking (PLL) mechanism, the system uses the attenuation rate of the acoustic impedance echo signal to infer the bending state of the guide wire, automatically compensates the driving voltage and fine-tunes the frequency to lock the resonance point.

[0051] This ensures that the mechanical impact work (Work Done) reaching the tip of the guidewire remains at an effective and constant threshold, regardless of how tortuous the vascular path may be, thus achieving precise treatment that is exactly what you see. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the hybrid drive host hardware architecture and serial coupling structure of the present invention;

[0054] Figure 2 This is a flowchart of the media identification and closed-loop control software logic of the present invention;

[0055] Figure 3 This is a schematic diagram of the time-division multiplexing drive timing and interference-free acquisition window of the present invention;

[0056] Figure 4 This is a schematic diagram illustrating the overall application scenario and dual-mode driving working principle of the present invention.

[0057] Figure 5 This is a schematic diagram comparing the acoustic impedance reflection characteristics of different media according to the present invention;

[0058] Figure 6 This is a schematic diagram of the dual closed-loop adaptive control principle based on AGC and PLL of the present invention. Detailed Implementation

[0059] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0060] Example 1;

[0061] like Figure 1 As shown, this embodiment provides an intravascular shockwave diagnostic device based on mechanical acoustic impedance feedback, including: a dual-mode drive unit, an acoustic impedance feedback sensing unit, and a control unit;

[0062] The dual-mode drive unit (composed of a voice coil motor and a piezoelectric stack) is configured to alternately output high-energy therapeutic pulse sequences and low-energy diagnostic pulse sequences;

[0063] The acoustic impedance feedback sensing unit (dynamic force sensor) is coupled to the output of the dual-mode drive unit and is used to acquire the acoustic impedance echo signal transmitted back through the guide wire.

[0064] The control unit (main control board) includes an FFT / PLL signal processing unit (used to execute the signal processing algorithm FFT and construct eigenvectors), an AGC power amplifier, and a DDS signal generator. Its control terminal is connected to the dual-mode drive unit to analyze the acoustic impedance echo signal characteristics (amplitude, spectral distribution, or attenuation rate). It allows high-energy output when high acoustic impedance characteristics (calcification) are identified and suppresses high-energy output when low acoustic impedance characteristics (soft tissue) are identified.

[0065] Specifically, by utilizing a series-coupled high-response speed voice coil motor and a piezo stack, it possesses dual-mode output capability:

[0066] Low-frequency therapeutic grade: Employs a voice coil motor (VCM) that responds to a 20-100Hz drive signal to generate large displacement impact.

[0067] High-frequency diagnostic stage: Employs a piezoelectric ceramic stack mechanically connected in series with the VCM output shaft. During the VCM's stationary or retracted phase, it generates a probe acoustic wave in response to a drive signal >20kHz.

[0068] Active braking, in this case, involves the VCM drive circuit incorporating reverse current braking for millisecond-level emergency stop upon detection of danger. It features dual-mode output capability and linear power regulation. The VCM drive circuit includes an AGC power amplifier and a DDS signal generator, capable of responding to control unit commands and linearly adjusting the output voltage / power within milliseconds, for example, within a 0-100% adjustment range, to support the transmission loss compensation (AGC) function described below.

[0069] Frequency modulation involves integrating a DDS signal generator or a high-precision PWM modulation module, enabling continuous frequency sweeping and fine-tuning within the range of 20-100Hz (treatment range) and >20kHz (diagnostic range) (frequency step accuracy better than 0.1Hz). This hardware feature supports the system in real-time tracking of the inherent frequency drift of the guidewire under different bending states, achieving resonance locking.

[0070] A high-frequency dynamic force sensor integrates a high-sensitivity dynamic load cell in series at the coupling interface between the drive shaft and the guidewire. This cell is used to capture the reaction force waveform near the proximal end of the guidewire, i.e., the acoustic impedance echo signal. The sensitivity needs to be able to detect mechanical echoes at the microjoule level, and it must have high-frequency response characteristics (>10kHz) to reproduce waveform details.

[0071] The smart interface includes a storage and reading unit (such as RFID, EEPROM, or a resistor-coded identification module) for reading the acoustic characteristic parameters of the guidewire.

[0072] This embodiment transforms blind injection into precision guidance, eliminating iatrogenic damage (existing technologies rely entirely on the doctor's touch, which is subject to lag). This invention confirms, through an algorithm, that the object in front is a stone rather than a blood vessel or flesh 10 milliseconds before each impact release, fundamentally reducing the risk of vascular perforation and dissection during CTO surgery.

[0073] Overcoming the physical limitations of guidewire conduction and ensuring treatment consistency, this method solves the industry-wide problem of uncontrollable energy due to bending of mechanical guidewires during long-distance transmission. Through closed-loop compensation, the treatment effect in deep tortuous blood vessels is consistent with that in straight blood vessels.

[0074] Software-defined hardware enables generational compatibility by reading guidewire identification data parameters. The host algorithm can be adapted to guide wires of different lengths and stiffnesses, ensuring control accuracy on different guide wires without changing the hardware, thus achieving decoupling of consumables.

[0075] Example 2;

[0076] Based on Example 1, such as Figure 2 As shown, the intravascular shock wave control method based on mechanical acoustic impedance feedback includes the following steps:

[0077] Step S1: Between treatment pulse cycles, when the doctor presses the foot pedal, a non-therapeutic micromechanical probe wave is emitted, which propagates from the proximal end of the guidewire to the distal end; this step is... Figure 2 The foot switch in the middle triggers and emits micro-energy diagnostic waves;

[0078] Step S2: The signal from the distal end of the guidewire is received at the proximal end. The residual echo from the proximal end is removed using a time window technique. The acoustic impedance echo signal from the distal end of the guidewire is extracted, and the actual total echo energy of the acoustic impedance echo signal is calculated. This step is... Figure 2 The echo signal was collected in the process;

[0079] Step S3: Perform a Fourier transform on the actual total echo energy of the acoustic impedance echo signal to extract the feature vector; this step is... Figure 2 FFT analysis in;

[0080] Step S4: Quantitatively compare the actual total echo energy and the proportion of high-frequency energy with the preset algorithm classification threshold; this step is... Figure 2 Does it exhibit high-frequency emission characteristics?

[0081] Step S5: When executing the treatment mode, the waveguide transmission attenuation coefficient is calculated based on the current actual total echo energy and the reference energy obtained based on the guidewire identity feature data. The driving parameters are automatically adjusted to compensate for losses, facilitating the output of energy-corrected treatment pulses. This step is... Figure 2 The calculation of attenuation (AGC), lock-in frequency (PLL), and output of high-energy therapeutic pulses are all included.

[0082] Example 3;

[0083] Based on Example 2, in step S1, the voice coil motor is locked, and only the piezoelectric stack is activated to emit a series of high-frequency micromechanical probe waves (e.g., a 20kHz pulse train). At this time, the micromechanical probe waves propagate from the proximal end of the guidewire to the distal end of the guidewire.

[0084] In step S2, during full-time acquisition, a dynamic force sensor located near the guidewire (at the handle interface) records the time-domain signal in real time for a period of time from the start of launch. This time-domain signal It integrates the oscillation aftershock signal from near-end emission and the acoustic impedance echo signal reflected back from the far end of the guidewire.

[0085] Time-domain separation employs a time window technique to separate time-domain signals. Set a start time and end time , Set to avoid the timing of near-end emission aftershocks, retaining only the time-domain signal. In arrive The signal within the time period is used as the effective acoustic impedance echo signal; Figure 3 The macroscopic timing of the system's diagnostics during the "cooling gap / diagnostic window" is demonstrated, while Figure 3The waveform segment marked "interference-free echo acquisition" is the pure acoustic impedance echo signal extracted after removing the aftershocks of the transmission using time window technology in this step.

[0086] Specifically, the energy of the extracted effective acoustic impedance echo signal is integrated to calculate the energy value of the current actual acoustic impedance echo signal. The calculation formula is as follows:

[0087] ;

[0088] in, For the sensor in time The collected voltage amplitude is proportional to the mechanical vibration amplitude; Represents instantaneous power; The total energy of the acoustic impedance echo signal or the total energy of the reflected wave is used to determine whether the proximal end of the guidewire has received the acoustic impedance echo signal from the distal end of the guidewire.

[0089] Acoustic impedance echo signal is a time-domain signal received after ultrasonic or electromagnetic waves are reflected at the interface of a medium. The total energy it carries is equal to the integral of the instantaneous power over the observation time. The signal energy (power) per unit time is represented by the signal energy (power) obtained after integration. arrive The total energy of the echo signal during this period, energy This reflects the combined effect of the intensity and duration of the echo signal, and that the total energy of the time-domain signal is equal to the total energy of its frequency-domain spectrum. Therefore, It is also equivalent to the sum of the energy distribution of the echo signal across the entire frequency band.

[0090] However, each time the proximal end of the guidewire is identified, the standard echo fingerprint of the guidewire is read. , The data originates from the built-in storage medium reading unit (such as RFID, EEPROM, or a resistance code identification module) in the guidewire handle, representing the ideal echo energy of the guidewire when it is straight. The parameters serve as a benchmark for measuring bending loss in the subsequent step S5 and are not involved in the qualitative identification of the medium in step S4.

[0091] In step S3, the acquired acoustic impedance echo signal (reflection signal) is subjected to FFT (Fast Fourier Transform) to extract feature vectors and compare them. Fourier Transform is a spectral transformation, which utilizes signal processing methods to transform the truncated time-domain signal. Execution length is The Fourier transform of the Fourier transform is calculated using the following formula:

[0092] ;

[0093] in, The output is the discrete frequency domain spectrum. It is the frequency point index in the frequency domain. For the first One frequency; The representative took from arrive All items are added together in sequence; The input is a discrete-time signal with a length of . , It is the time-domain sampling point number. ; The total number of sampling points for the signal (which is the DFT transform length) determines the frequency domain resolution. The imaginary unit; It is a complex exponential basis function, which is essentially a twitch factor and represents sine or cosine basis signals of different frequencies; is the base of the natural logarithm. The value is 2.71828.

[0094] This formula is used to express a discrete signal in the time domain. The frequency domain representation is obtained by decomposing the signal into a weighted sum of complex sinusoidal signals of different frequencies. Each This represents the frequency of the original signal. The amplitude and phase information of the components.

[0095] In fields such as digital signal processing, communications, image processing, and speech recognition, the DFT is fundamental for analyzing signal spectra and performing operations such as filtering, compression, modulation, and demodulation. The Fast Fourier Transform (FFT) is a highly efficient algorithm that significantly reduces computational complexity.

[0096] As a piece of sound, image, or sensor data, This involves breaking down the data into stripes of different frequencies to obtain the signal distribution along the frequency dimension, thereby discovering patterns that are not easily noticeable in the time domain.

[0097] Feature vector extraction is the high-frequency energy percentage of key quantitative indicators calculated from the spectrum. To calculate the cutoff frequency above 10kHz The proportion of high-frequency energy is given by the following formula:

[0098] ;

[0099] in, This represents the proportion of high-frequency energy in the total signal energy, and its value ranges from 0 to 1. For high-frequency energy; Indicates the first Energy at a frequency; The high-frequency boundary frequency index defines the starting position of the high-frequency band; This indicates that due to the conjugate symmetry of the total number of sampling points of the signal (the DFT of the signal), the effective frequency range is 0- (Nyquist frequency), therefore, the upper limit of the summation is taken as ; This represents the actual acoustic impedance echo signal energy value.

[0100] Frequency component extraction is based on the proportion of high-frequency energy. ,because The value range is 0-1:

[0101] If the value is close to 1, the signal energy is mainly concentrated in the high-frequency band, indicating that the signal has a rich high-frequency component (such as noise, abrupt changes, and many details).

[0102] When the RHF is close to 0, the signal energy is mainly concentrated in the low frequency band, indicating that the signal is smooth and low frequency dominates (e.g., a slow changing trend).

[0103] Used for signal analysis (such as vibration signals, speech, and images), it assesses the proportion of high-frequency features in a signal and can be applied to scenarios such as fault diagnosis, noise detection, and texture analysis.

[0104] Boundary frequency The boundary point can be set manually or automatically by experience or algorithms based on the actual application scenario. For example, 50% or 70% of the Nyquist frequency can be used as the dividing point.

[0105] In step S4, the actual acoustic impedance echo signal energy value will be calculated. The proportion of high-frequency energy in key quantitative indicators calculated from the spectrum. Compared with the preset algorithm classification threshold ( , and Compare, such as Figure 4 and Figure 5 As shown, specifically:

[0106] The quantitative determination criteria for target-locked lesions in scenario A are as follows: energy judgment criteria:

[0107] This indicates that the total echo energy is higher than the preset effective detection threshold, used to eliminate interference; where, The contact threshold with a hard object;

[0108] Frequency domain judgment criteria: This indicates that the proportion of high-frequency components exceeds a preset ratio, for example, >30%, representing high-frequency harmonics generated by head-on collisions; among which... This is the threshold for the proportion of high-frequency events;

[0109] The system determined that the preceding medium had high acoustic impedance and a hard texture, confirming it as a calcified lesion.

[0110] Specifically, the determination of calcification (treatment mode) is based on the actual total echo energy. Higher than or equal to the hard object contact threshold And the proportion of high-frequency energy Higher than or equal to the high frequency percentage threshold The lesion was diagnosed as calcified; the system further compared the current echo energy. Compared with the reference energy The difference is used to calculate the waveguide transmission loss coefficient, automatically adjust the driving parameters to compensate for the loss, and output the energy-corrected therapeutic pulse.

[0111] The action performed is PLL phase-locked loop control and treatment, unlocking the voice coil motor and releasing standard treatment pulses;

[0112] PLL frequency locking involves activating the digital phase-locked loop (PDL) module, which then monitors the time-domain signal in real time. The driving voltage signal in ) and phase difference ( ).

[0113] like > The digital phase-locked loop module reduces the drive frequency.

[0114] like < The digital phase-locked loop module increases the drive frequency.

[0115] Through continuous fine-tuning, Approaching 0 (or the system's inherent resonant phase angle), thus ensuring that the system always operates at the current mechanical resonant frequency of the guidewire, achieving maximum energy transmission efficiency.

[0116] For scenario B, contact with blood vessel walls / soft tissue (Safety Warning), the quantitative judgment criteria are:

[0117] Frequency domain criteria: and Even if the total energy If the proportion of high-frequency signals is below a threshold, it indicates that the high-frequency signals are absorbed by the soft tissue, and this is considered a soft contact; among them, This is the system noise floor threshold or the upper limit of sensor readings under no-load conditions.

[0118] The system determined that the area in front was either a blood vessel wall or a soft plaque.

[0119] Specifically, determining soft tissue (safe mode) involves considering the actual total echo energy. Higher than or equal to the noise floor threshold But high-frequency energy percentage Below the high frequency percentage threshold If the target is identified as a blood vessel wall or soft tissue, a safety gate is triggered, automatically cutting off the high-energy output.

[0120] The action is to trigger the safety gate, instantly cutting off the high-energy output, or to maintain only a very low-energy micro-vibration to provide tactile feedback, prompting the user to adjust their position and prevent perforation.

[0121] For scenario C, which involves suspension / blood (Idle), the quantitative determination condition is the energy criterion (any condition satisfying the criteria belongs to scenario C):

[0122] Scenario 1 (Completely Floating) .

[0123] Scenario 2 (weak contact / incomplete contact) and .

[0124] Specifically, determining levitation (standby mode) is based on the actual total energy of the echo. Below the noise floor threshold Or the actual total energy of the echo Higher than or equal to the noise floor threshold But below or equal to the hard object contact threshold And the proportion of high-frequency energy Higher than or equal to the high frequency percentage threshold The lock-on drive output is determined to be floating.

[0125] The action performed is to lock the voice coil motor to prevent dry firing that could lead to fatigue and breakage of the guide wire.

[0126] In step S5, when the mechanical wave propagates in the metal guidewire (waveguide), its energy loss is nonlinearly positively correlated with the bending angle of the guidewire. In severely tortuous blood vessels, the mechanical conduction efficiency of long guidewires may decrease by 30%-50%. Without compensation, the actual impact force reaching the tip will be insufficient to break the hard calcification; if the power is blindly increased, it may cause the guidewire to break due to stress overload in straight blood vessel segments.

[0127] The compensation algorithm logic (AGC closed-loop control) utilizes the attenuation characteristics of the acoustic impedance echo to infer the bending state of the guidewire and automatically adjusts the driving voltage of the therapeutic wave; for example... Figure 6 As shown, the details are as follows:

[0128] Triggering condition: The compensation algorithm in this step is executed only when the judgment result is scenario A (contact with lesion).

[0129] Benchmark Establishment: Calling the established standard echo fingerprint This benchmark is not a fixed constant of the host, but is loaded based on the "guidewire identity feature data" of the currently connected guidewire, ensuring that the algorithm can adapt to the manufacturing differences of different batches or models of guidewires.

[0130] Real-time deviation calculation: The waveguide transmission attenuation coefficient is calculated as follows:

[0131] ;

[0132] in, The waveguide transmission attenuation coefficient or loss rate is a dimensionless or percentage form that represents the proportion of signal wave attenuation during transmission. This represents the ideal echo energy of the guidewire when it is straight. This represents the actual acoustic impedance echo signal energy value; the molecule part This represents the attenuation of the electric field amplitude during signal wave propagation in the waveguide, directly reflecting the magnitude of energy loss; the denominator... It converts absolute attenuation into relative attenuation ratio, which facilitates comparison of loss performance under different waveguide structures and frequencies.

[0133] Since the frequency domain characteristics confirmed it was a hard contact, therefore, The reduction is likely due to guide wire bending or transmission loss, rather than media softening.

[0134] Drive voltage compensation: Adjusting drive parameters to compensate for losses, this automatically increases the drive voltage of the next treatment pulse based on the waveguide transmission attenuation coefficient. :

[0135] ;

[0136] in, This refers to the waveguide transmission attenuation coefficient or loss rate. Basic treatment voltage; To compensate for the gain coefficient, the driving voltage of the next treatment pulse is adjusted. This ensures that no matter how tortuous the blood vessel or how much the waveguide transmission attenuation coefficient decreases, the actual mechanical impact power output from the guidewire tip can always effectively break the stone, achieving a constant chisel force output.

[0137] The time-domain separation technique in this embodiment protects a timing control method that inserts into the diagnostic and treatment interval. It emits micro-energy diagnostic waves within the cooling interval between two high-energy treatment pulses and utilizes time window technology to set the start time of signal acquisition. and end time In the time domain, the oscillation aftershock interference during near-end emission is eliminated, and only the pure acoustic impedance echo signal from the far end of the guidewire is extracted and integrated within the time window.

[0138] The bending compensation algorithm is a compensation strategy that estimates wire bending loss based on the energy attenuation ratio of acoustic impedance echo signal and automatically increases the driving voltage.

[0139] Resonance locking is a phase-locked loop (PLL) control method that uses the echo phase difference to adjust the drive frequency in real time, so that the system always works at the resonant frequency of the guidewire. It uses the attenuation rate of the acoustic impedance echo signal to infer the bending state of the guidewire, automatically compensates the drive voltage and fine-tunes the frequency to lock the resonant point.

[0140] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope described in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling intravascular shock waves based on mechanical acoustic impedance feedback, characterized in that, Includes the following steps: Step S1: Between treatment pulse cycles, a non-therapeutic micromechanical probe wave is emitted, which propagates from the proximal end of the guidewire to the distal end. Step S2: The proximal end of the guidewire receives the signal from the distal end of the guidewire, and the emission aftershock from the proximal end of the guidewire is removed using time window technology. The acoustic impedance echo signal from the distal end of the guidewire is extracted, and the actual total echo energy of the acoustic impedance echo signal is calculated. Step S3: Perform a Fourier transform on the actual total echo energy of the acoustic impedance echo signal to extract the feature vector; Step S4: Quantitatively compare the actual total echo energy and the proportion of high-frequency energy with the preset algorithm classification threshold; Step S5: When executing the treatment mode, the waveguide transmission attenuation coefficient is calculated based on the current actual total echo energy and the reference energy obtained based on the guidewire identity feature data. The driving parameters are automatically adjusted to compensate for the loss, so as to output the energy-corrected treatment pulse.

2. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S1, the voice coil motor is locked, and the piezoelectric stack is activated to emit a high-frequency micromechanical probe wave, which then propagates along the guide wire; wherein the high-frequency micromechanical probe wave is a pulse train greater than or equal to 20 kHz.

3. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S2, a dynamic force sensor located near the guidewire records the time-domain signal in real time over a period of time from the start of emission. The time-domain signal It integrates the oscillation aftershock signal from near-end emission and the acoustic impedance echo signal reflected back from the far end of the guidewire.

4. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 3, characterized in that, In step S2, the time windowing technique involves dividing the time-domain signal... Set a start time and end time , Set to avoid the timing of near-end emission aftershocks, retaining only the time-domain signal. In arrive The signal within the time period is used as the effective acoustic impedance echo signal; Specifically, the energy of the extracted effective acoustic impedance echo signal is integrated to calculate the energy value of the current actual acoustic impedance echo signal. The calculation formula is as follows: ； in, For the sensor in time The collected voltage amplitude is proportional to the mechanical vibration amplitude; Represents instantaneous power; The total energy of the acoustic impedance echo signal or the total energy of the reflected wave is used to determine whether the proximal end of the guidewire has received the acoustic impedance echo signal from the distal end of the guidewire.

5. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S3, the Fourier transform is a spectral transform, which is a signal processing method used to transform the truncated time-domain signal. Execution length is The Fourier transform of the Fourier transform is calculated using the following formula: ； in, The output is the discrete frequency domain spectrum. It is the frequency point index in the frequency domain. For the first One frequency; The representative took from arrive All items are added together in sequence; The input is a discrete-time signal with a length of . , It is the time-domain sampling point number. ; The total number of sampling points for the signal determines the frequency domain resolution; The imaginary unit; It is a complex exponential basis function, which is essentially a twitch factor and represents sine or cosine basis signals of different frequencies; is the base of the natural logarithm.

6. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S3, the extracted feature vector is the high-frequency energy proportion of key quantitative indicators calculated from the spectrum. To calculate the cutoff frequency above 10kHz The proportion of high-frequency energy is given by the following formula: ； in, This represents the proportion of high-frequency energy in the total signal energy, and its value ranges from 0 to 1. For high-frequency energy; Indicates the first Energy at a frequency; The high-frequency boundary frequency index defines the starting position of the high-frequency band; This indicates that due to the conjugate symmetry of the total number of signal sampling points, the effective frequency range is 0- Therefore, the upper limit of the summation is taken as ; This represents the energy value of the actual acoustic impedance echo signal.

7. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S4, the actual acoustic impedance echo signal energy value will be calculated. The proportion of high-frequency energy in key quantitative indicators calculated from the spectrum. The comparison is performed against a preset algorithm classification threshold, specifically: The quantitative criteria for determining contact with lesions are based on energy judgment criteria: This indicates that the total echo energy is higher than the preset effective detection threshold, used to eliminate interference; where, The contact threshold with a hard object; Frequency domain judgment criteria: ,in, When the proportion of high-frequency components exceeds a preset ratio, it represents the high-frequency harmonics generated by the head-on collision; among which... This is the threshold for the proportion of high-frequency events; The system determined that the preceding medium had high acoustic impedance and a hard texture, confirming it as a calcified lesion. The action performed is to unlock the voice coil motor and release a standard therapeutic pulse; For contact with blood vessel walls or soft tissues, the quantitative determination criteria are: Frequency domain criteria: and Even if the total energy If the proportion of high-frequency signals is below a threshold, it indicates that the high-frequency signals are absorbed by the soft tissue, and this is considered a soft contact; among them, This is the system noise floor threshold or the upper limit of sensor readings under no-load conditions. The system determined that the area in front was either a blood vessel wall or a soft plaque. The action is to trigger a safety gating system, instantly cutting off high-energy output, or simply maintaining a very low-energy micro-vibration to provide tactile feedback, prompting the user to adjust their position and preventing perforation.

8. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S5, the waveguide transmission attenuation coefficient is calculated as follows: ； in, The waveguide transmission attenuation coefficient or loss rate is a dimensionless or percentage form that represents the proportion of signal wave attenuation during transmission. This represents the ideal echo energy of the guidewire when it is straight. This represents the actual acoustic impedance echo signal energy value; the molecule part This represents the attenuation of the electric field amplitude during signal wave propagation in the waveguide, directly reflecting the magnitude of energy loss; the denominator... It converts absolute attenuation into relative attenuation ratio, which facilitates comparison of loss performance under different waveguide structures and frequencies.

9. The intravascular shock wave control method based on mechanical acoustic impedance feedback according to claim 1, characterized in that, In step S5, adjusting the driving parameters to compensate for losses involves automatically increasing the driving voltage of the next treatment pulse based on the waveguide transmission attenuation coefficient. : ； in, This refers to the waveguide transmission attenuation coefficient or loss rate. Basic treatment voltage; To compensate for the gain coefficient, the driving voltage of the next treatment pulse is adjusted. This ensures that no matter how tortuous the blood vessel or how much the waveguide transmission attenuation coefficient decreases, the actual mechanical impact power output from the guidewire tip can always effectively break the stone, achieving a constant chisel force output.

10. A diagnostic device for intravascular shock waves based on mechanical acoustic impedance feedback, used to execute the intravascular shock wave control method based on mechanical acoustic impedance feedback according to any one of claims 1-9, characterized in that, include: The dual-mode drive unit is configured to alternately output high-energy therapeutic pulse sequences and low-energy diagnostic pulse sequences; The acoustic impedance feedback sensing unit, coupled to the output of the dual-mode drive unit, is used to acquire the acoustic impedance echo signal transmitted back through the guide wire. The control unit, whose control terminal is connected to the dual-mode drive unit, is used to analyze the acoustic impedance echo signal characteristics, and to allow high-energy output when high acoustic impedance characteristics are detected, and to suppress high-energy output when low acoustic impedance characteristics are detected.

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