Extracorporeal shock wave therapy apparatus personalized parameter recommendation method based on medical data

Abstract

This invention relates to the field of extracorporeal shock wave technology and discloses a method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data. The method includes: acquiring ultrasound images of a patient in a specific knee-flexed posture, extracting lesion and bone surface feature information, and calculating the effective incident angle and lesion depth; determining the waveguide matching angle and the main lobe angle width based on soft tissue sound velocity, bone Rayleigh phase velocity, and device characteristics, and establishing an angle distribution model to calculate the angular energy ratio. When the energy distribution is abnormal, the treatment head rotation angle and skin translation are automatically adjusted to keep the focus aligned with the lesion center; the energy flux density is adjusted based on tissue attenuation characteristics to obtain the nominal energy flux density; treatment points are arranged along the long axis of the patellar tendon, and shock waves are emitted only at locations where the angular energy ratio meets the threshold, thereby generating a personalized treatment parameter scheme to achieve precise focusing and individualized control of the treatment energy.

Description

Technical Field

[0001] This invention relates to the field of extracorporeal shock wave technology, and more specifically, to a method for recommending personalized parameters for extracorporeal shock wave therapy devices based on medical data. Background Technology

[0002] Extracorporeal shock wave therapy (ESWT), as a non-invasive physical therapy device, is widely used in the clinical treatment of musculoskeletal diseases. Focused electromagnetic shock waves generate high-voltage pulses through coils and metal diaphragms, which are then focused by an acoustic lens onto specific lesions within the body. It is commonly used to treat deep patellar tendinitis, periostitis, and calcific tendinitis. Current equipment treatment parameters, such as energy flux density, pulse count, depth of focus, and treatment angle, are typically based on physical data calibrated by the manufacturer in an ideal water bath environment. Clinicians adjust the energy level and incident direction based on experience, but quantitative, individualized guidance is lacking. Due to significant differences in patients' tissue structures (such as subcutaneous fat thickness, tendon depth, and bone morphology), the same equipment settings often produce different tissue responses and therapeutic effects on different individuals, potentially leading to insufficient efficacy or local discomfort. This indicates that relying solely on water bath calibration or experience-based adjustments is insufficient to meet the treatment needs of deep lesions.

[0003] During focused electromagnetic shockwave therapy, the shockwave energy needs to penetrate multiple layers of tissue, including skin, fat, fascia, and tendons, to reach the lesion area located near the inferior pole of the patella or the tibial tuberosity. This area is adjacent to the bone cortex, where there are significant differences in acoustic impedance. Upon encountering the bone interface, the shockwave undergoes reflection and mode conversion; some energy propagates along the bone surface, while energy attenuation and focal point drift may occur in the deep tendon region. Simultaneously, the spatial energy distribution in the device's focal zone exhibits high directionality due to the influence of its aperture size, focal length, and acoustic lens geometry. When the angle of incidence approaches a certain range from the angle to the bone surface, the wave energy tends to concentrate on the bone surface rather than forming an ideal focal point within the tendon. Clinically, some patients with deep patellar tendinopathy have been observed to experience insufficient therapeutic effect or increased surface pain under the same parameters, which stems from this spatial energy distribution shift. Summary of the Invention

[0004] This invention provides a method for recommending personalized parameters for extracorporeal shock wave therapy devices based on medical data, which solves the technical problem that when the energy propagation direction of the device forms a specific angular relationship with the bone surface during focused electromagnetic extracorporeal shock wave therapy for deep patellar tendinopathy, the energy will be abnormally concentrated on the bone surface while the effective energy inside the tendon will decrease, resulting in focus shift and dose distortion. Existing fixed parameters and experience-based adjustment methods cannot accurately identify and correct this deviation.

[0005] This invention provides a method for recommending personalized parameters for extracorporeal shock wave therapy devices based on medical data, including:

[0006] Acquire ultrasound images of the patient with knee flexed at 20 to 30 degrees, extract the coordinates of the lesion center, the normal vector of the cortical bone surface, and the axial vector of the treatment head, and calculate the effective incident angle and lesion depth.

[0007] Based on the sound velocity in soft tissue, Rayleigh phase velocity in cortical bone, effective aperture of the device, and dominant frequency band, the waveguide matching angle and the main lobe angle width of the angular spectrum are determined.

[0008] An angular distribution model is used to calculate the angular energy percentage in the angular domain corresponding to the waveguide matching angle;

[0009] If the angular energy percentage is higher than the preset angular energy percentage threshold, adjust the rotation angle of the treatment head according to the main flap angle width of the angular spectrum and determine the amount of skin translation so that the angular energy percentage is reduced to within the threshold and the focus remains aligned with the center of the lesion.

[0010] The shock wave propagation path length is calculated based on the lesion depth and the rotation angle of the treatment head. Combined with the tissue frequency attenuation coefficient and the angular energy ratio, the energy flux density is set back to obtain the nominal energy flux density.

[0011] Treatment points are arranged along the long axis of the patellar tendon. The effective incident angle and angular energy ratio are recalculated for each treatment point. Shock waves are emitted only at treatment points where the angular energy ratio is lower than the preset angular energy ratio threshold, generating a treatment scheme that includes nominal energy flux density, treatment point position and emission parameters.

[0012] The beneficial effects of this invention include: by combining the patient's ultrasound imaging data with an acoustic propagation model, a personalized shock wave parameter recommendation system is established, enabling the quantitative and individualized adjustment of treatment parameters (energy flux density, incident angle, treatment point arrangement, etc.). Compared with traditional settings based on experience or factory calibration, this invention can automatically calculate the optimal incident angle and energy distribution based on physiological differences such as the patient's soft tissue sound velocity, bone surface angle, and lesion depth, avoiding the problem of abnormal concentration of shock waves on the bone surface and effectively improving the energy utilization rate and treatment accuracy of the intratendon focal point. Simultaneously, by dynamically adjusting the treatment head rotation angle and skin translation, the focal point is kept aligned with the lesion center, significantly reducing superficial pain and energy waste, thereby improving the treatment effect and safety of deep patellar tendinopathy and other lesions. It possesses high intelligence, reliability, and clinical application value. Attached Figure Description

[0013] Figure 1 This is a flowchart of the personalized parameter recommendation method for an extracorporeal shock wave therapy device based on medical data, according to the present invention. Detailed Implementation

[0014] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0015] like Figure 1 As shown, the method for recommending personalized parameters for extracorporeal shock wave therapy devices based on medical data includes:

[0016] Acquire ultrasound images of the patient with knee flexed at 20 to 30 degrees, extract the coordinates of the lesion center, the normal vector of the cortical bone surface, and the axial vector of the treatment head, and calculate the effective incident angle and lesion depth.

[0017] Based on the sound velocity in soft tissue, Rayleigh phase velocity in cortical bone, effective aperture of the device, and dominant frequency band, the waveguide matching angle and the main lobe angle width of the angular spectrum are determined.

[0018] An angular distribution model is used to calculate the angular energy percentage in the angular domain corresponding to the waveguide matching angle;

[0019] If the angular energy percentage is higher than the preset angular energy percentage threshold, adjust the rotation angle of the treatment head according to the main flap angle width of the angular spectrum and determine the amount of skin translation so that the angular energy percentage is reduced to within the threshold and the focus remains aligned with the center of the lesion.

[0020] The shock wave propagation path length is calculated based on the lesion depth and the rotation angle of the treatment head. Combined with the tissue frequency attenuation coefficient and the angular energy ratio, the energy flux density is set back to obtain the nominal energy flux density.

[0021] Treatment points are arranged along the long axis of the patellar tendon. The effective incident angle and angular energy ratio are recalculated for each treatment point. Shock waves are emitted only at treatment points where the angular energy ratio is lower than the preset angular energy ratio threshold, generating a treatment scheme that includes nominal energy flux density, treatment point position and emission parameters.

[0022] In one embodiment of the present invention, ultrasound images of a patient with their knee flexed at 20 to 30 degrees are acquired, and the coordinates of the lesion center, the normal vector of the cortical bone surface, and the axial vector of the treatment head are extracted. The effective incident angle and lesion depth are calculated, including:

[0023] Establish a three-dimensional coordinate system corresponding to the ultrasound image;

[0024] Determine the coordinates of the intersection point between the skin contact surface and the axis of the treatment head;

[0025] The effective angle of incidence is obtained by dividing the inner product of the treatment head axial vector and the cortical bone surface normal vector by the product of the length of the treatment head axial vector and the length of the cortical bone surface normal vector, and then taking the inverse cosine value.

[0026] The lesion depth is obtained by taking the inner product of the vector obtained by dividing the axial vector of the treatment head by its own length, the vector obtained by subtracting the coordinates of the intersection point of the skin contact surface and the axis of the treatment head from the coordinates of the lesion center, and then taking the absolute value.

[0027] The method for establishing a three-dimensional coordinate system is as follows:

[0028] The right-handed coordinate system is adopted, with the projection point of the geometric center of the ultrasound probe onto the patient's skin surface as the origin of the coordinate system. The directions of the three axes are consistent with the patient's body: the left-right direction is the first axis, with the patient's right side as the positive direction; the front-back direction is the second axis, with the patient's front as the positive direction; and the vertical inward direction from the skin surface is the third axis, with the deep tissue as the positive direction.

[0029] Acquire continuous ultrasound slice images in a knee-flexed position, keeping the spacing between adjacent slices fixed (usually the minimum scanning interval of the device). Map each two-dimensional slice to a three-dimensional coordinate system according to its actual scanning position. Determine the coordinates of each pixel on the slice on the third axis and the first and second axes based on the scanning depth and slice number. Finally, combine them to form a three-dimensional coordinate space that completely corresponds to the anatomical structure of the detected area.

[0030] Determine the coordinates of the intersection point between the skin contact surface and the axis of the treatment head, specifically including:

[0031] In ultrasound imaging, the skin area appears as a strong echo band. The outermost boundary of this echo band is taken as the location marker of the skin contact surface. The boundary is continuously traced along the first and second axes of the three-dimensional coordinate system to form the three-dimensional contour of the skin contact surface.

[0032] The physical axis of the treatment head is its central symmetry line. During operation, the direction of the axis is determined by the positioning marks on the device (such as the scale lines on the side of the probe). The axis is presented as a virtual straight line in the three-dimensional coordinate system. The starting point of the straight line can be set as the center point of contact between the treatment head and the skin (estimated according to the preset treatment position when there is no contact).

[0033] Extend the virtual straight line toward the skin until it intersects with the previously determined three-dimensional contour of the skin contact surface. This intersection point is the intersection of the skin contact surface and the axis of the treatment head, and its coordinates are read directly from the three-dimensional coordinate system.

[0034] Extracting the cortical bone surface normal vector includes:

[0035] In ultrasound imaging, cortical bone appears as a continuous, strongly echogenic bright line. This bright line is highlighted through image enhancement processing, and the direction of the bright line is traced along the lesion area (such as the inferior pole of the patella at the attachment of the patellar tendon) to determine the three-dimensional morphology of the cortical bone surface.

[0036] In the cortical bone surface area corresponding to the center of the lesion, at least three non-collinear feature points are selected evenly. The feature points should be located on the strong echo line and distributed in a flat area around the lesion, avoiding the selection of sharp parts of the bone edge.

[0037] A local plane is fitted based on the coordinates of three feature points (this plane is consistent with the morphology of the cortical bone surface in this region), and then the direction vector perpendicular to this plane is determined, where the direction pointing to the lesion side is the normal vector of the cortical bone surface.

[0038] The direction of the axial vector of the treatment head is consistent with the physical emission direction of the treatment head. During operation, the orientation of the treatment head is first determined by the positioning system of the device (such as whether it is perpendicular to the skin surface or at a certain angle), and then converted into a vector by combining the direction rules of the three-dimensional coordinate system: if the treatment head is perpendicular to the deep layer of the skin, the axial vector is completely consistent with the direction of the third axis of the coordinate system; if there is a tilt, the vector direction is adjusted according to the tilt angle to ensure that the vector direction is always consistent with the emission path of the shock wave from the treatment head.

[0039] After obtaining the axial vector of the treatment head and the normal vector of the cortical bone surface, the effective angle of incidence is determined as follows: Imagine the two vectors originating from the same point, and measure the angle between them. This angle is the effective angle of incidence. Essentially, it determines the degree of deviation between the emission direction of the treatment head and the perpendicular direction of the cortical bone surface. The smaller the angle, the closer the emission direction is to the perpendicular direction of the cortical bone.

[0040] First, adjust the axial vector of the treatment head to a standard direction with a fixed length (i.e., keep the direction unchanged and the length uniform). Then, construct a straight line from the intersection point to the center of the lesion. By measuring the degree of coincidence between the axial vector in the standard direction and this straight line from the intersection point to the lesion, the lesion depth is obtained. The lesion depth represents the actual distance from the skin surface to the lesion along the axial direction of the treatment head.

[0041] In one embodiment of the present invention, determining the waveguide matching angle and the main lobe width of the angular spectrum based on the sound velocity in soft tissue, the Rayleigh phase velocity in cortical bone, the effective aperture of the device, and the dominant frequency band includes:

[0042] The waveguide matching angle is obtained by taking the arcsine of the quotient of the soft tissue sound velocity divided by the Rayleigh phase velocity of the cortical bone.

[0043] The main lobe width of the angular spectrum is obtained by multiplying the constant 1.22 by the soft tissue sound velocity, and then dividing by the product of the dominant frequency band and the effective aperture of the device.

[0044] Soft tissue sound velocity: refers to the speed at which shock waves propagate in soft tissues such as muscles, fat, and tendons in the human body. It is a parameter that describes how fast shock waves move in the shallow medium of the treatment area.

[0045] Rayleigh phase velocity in cortical bone: Rayleigh waves are elastic waves that propagate along the surface of a solid. The Rayleigh phase velocity in cortical bone is the speed at which this wave propagates in the surface layer of cortical bone. Its value is much greater than the speed of sound in soft tissue and is related to the density, hardness and other properties of cortical bone.

[0046] Effective aperture of the device: refers to the effective diameter of the acoustic element in the extracorporeal shock wave therapy head that actually participates in the focusing and emission of the shock wave. It is not the physical size of the treatment head, but a device parameter that determines the focusing accuracy and energy distribution range of the shock wave.

[0047] Dominant frequency band: A shock wave is a non-periodic signal whose energy is not concentrated at a single frequency, but rather distributed over a certain frequency range. The dominant frequency band is the core frequency range within this range where the energy is most concentrated, influencing the penetration depth and tissue-specific effects of the shock wave.

[0048] Determining the sound velocity in soft tissue can be achieved in two ways. First, one can directly use conventional empirical values ​​from the medical field. These values ​​have been validated through numerous experiments and show minimal variation in soft tissue across different parts of the body, thus meeting basic calculation requirements. Second, for higher precision, local measurements can be taken in the soft tissue region surrounding the lesion using ultrasound equipment before treatment to obtain specific values ​​tailored to the patient.

[0049] Determining the Rayleigh phase velocity in cortical bone requires measurement using specialized ultrasound phase correction technology. Before treatment, echo signals from the cortical bone at the lesion site are acquired using ultrasound equipment. By analyzing the propagation delay and phase changes of the signal on the bone surface, the Rayleigh wave propagation velocity of the patient's cortical bone surface is calculated. In clinical practice, a preliminary value can be obtained by referring to the typical range of Rayleigh phase velocities in cortical bone of the same age group and bone location (usually much larger than the sound velocity in soft tissue), and then fine-tuned based on the patient's specific bone mineral density test results.

[0050] Determine the effective aperture of the device: This can be obtained directly from the manufacturer's technical specifications for the shockwave therapy device. The manufacturer will clearly indicate the effective aperture value for different treatment heads in the product manual. This parameter is a fixed value calibrated during device manufacturing and does not require user measurement. For example, the effective aperture of a handheld focused therapy head might be specified as 40 mm; this value should be used as the basis for calculation.

[0051] Determining the dominant frequency band: This is achieved through spectrum analysis. Using pressure sensing devices such as hydrophones, the shock wave signal emitted by the treatment head is collected in a standard water bath environment. The signal is then imported into signal processing software for spectrum analysis to identify the frequency range with the highest energy amplitude. This range is the dominant frequency band of the device. The device's instruction manual usually also provides the calibrated dominant frequency band range.

[0052] The waveguide matching angle is calculated as follows:

[0053] When a shock wave propagates from soft tissue to the cortical bone surface, some energy may be converted into Rayleigh waves (a type of guided wave) propagating along the bone surface. This results in reduced effective treatment energy within the tendon and excessive energy concentration on the bone surface. The guided wave matching angle is a key angle used to assess this energy conversion risk. When the incident direction of the shock wave approaches this angle, the proportion of energy converted into Rayleigh waves increases significantly. Calculating this angle by the ratio of the sound velocity in soft tissue to the Rayleigh phase velocity in cortical bone essentially involves finding the critical matching value of wave velocities in the two media.

[0054] The main lobe angular width of the angular spectrum is calculated as follows:

[0055] The energy of a shock wave is not uniformly distributed in space, but concentrated within a certain core angular range. The width of this range is the main lobe width of the angular spectrum. The constant 1.22 is a classic parameter describing the energy concentration range under a circular aperture. Even if the shock wave is a mechanical wave, its focused energy distribution is similar to the energy distribution of optical circular aperture diffraction, so this constant can be used. By calculating the main lobe width using the sound velocity in soft tissue, the dominant frequency band, and the effective aperture of the device, the angular range where the shock wave energy is most concentrated can be accurately quantified. Combined with the waveguide matching angle, it can be further determined whether the core energy will fall into the angular range that is easily converted into guided waves.

[0056] The waveguide matching angle is calculated as follows:

[0057] The first step is to obtain the specific values ​​of sound velocity in soft tissue and Rayleigh phase velocity in cortical bone;

[0058] The second step is to divide the sound velocity in soft tissue by the Rayleigh phase velocity in cortical bone to obtain a ratio value less than one.

[0059] The third step is to use an angle calculation tool to find the angle corresponding to the ratio value (i.e., the result of arcsine calculation). This angle is the waveguide matching angle, which is usually small and represents the critical incident direction where energy is easily converted to the bone surface.

[0060] The main lobe angular width of the angular spectrum is calculated as follows:

[0061] The first step is to collect the values ​​of four parameters: constant 1.22, soft tissue sound velocity, dominant frequency band, and effective aperture of the device.

[0062] The second step is to first calculate the product of the dominant frequency band and the effective aperture of the device, and then calculate the product of the constant 1.22 and the sound velocity of soft tissue.

[0063] The third step is to divide the product of the latter by the product of the former. The result is the main lobe angular width of the angular spectrum. The larger this value is, the more dispersed the energy distribution of the shock wave is, and vice versa.

[0064] In one embodiment of the present invention, an angular distribution model is used to calculate the angular energy percentage within the angular domain corresponding to the waveguide matching angle, including:

[0065] A Gaussian angular distribution model is established. The standard deviation of the Gaussian angular distribution model is obtained by dividing the main lobe angular width of the angular spectrum by two times the natural logarithm of 2. The relative intensity function of the Gaussian angular distribution model is constructed based on the difference between the angular variable and the effective incident angle.

[0066] Determine the lower and upper bounds of the angular domain corresponding to the waveguide matching angle. The lower bound of the angular domain is the waveguide matching angle minus half of the main lobe width of the angular spectrum, and the upper bound of the angular domain is the waveguide matching angle plus half of the main lobe width of the angular spectrum.

[0067] Calculate the angular energy percentage, which is the integral of the relative intensity function between the lower and upper boundaries of the angular domain, divided by the integral of the relative intensity function between -90 degrees and 90 degrees.

[0068] The Gaussian model was chosen because the angular spectrum energy distribution of shock waves exhibits a bell-shaped property, with strong energy in the middle and weak energy on both sides, which closely matches the shape of the Gaussian distribution. Furthermore, the Gaussian model is easy to calculate and can quickly quantify the energy proportion at different angles, making it suitable for real-time parameter calculations in clinical treatment.

[0069] The mean of the Gaussian model is set as the effective incident angle of the current treatment head (i.e., the angle at which the treatment head is actually facing), representing the reference angle where the energy is most concentrated.

[0070] The standard deviation of the Gaussian model ensures that the energy concentration range of the model is consistent with the actual main lobe angle width of the shock wave. For example, if the main lobe angle width is five degrees, the calculated standard deviation is approximately two degrees. In this case, about 90% of the energy in the Gaussian model will be concentrated within the range of the mean plus or minus five degrees, matching the main lobe angle width.

[0071] Model validation methods include:

[0072] Before treatment, the applicability of the model is verified through a water tank experiment. The treatment head is placed in a standard water tank, and the shock wave intensity is collected at different angles using an angle-adjustable pressure sensor. The collected intensity data is compared with the calculation results of the Gaussian model. If the error between the two is less than 5%, it means that the model is suitable for the current equipment. If the error is large, the calculation coefficient of the standard deviation can be fine-tuned (such as increasing or decreasing the original coefficient by 5%) until the model matches the actual data.

[0073] Angle variable: refers to the angle formed between the shock wave emitted from the treatment head and the axial vector of the treatment head during its propagation, i.e., the deviation angle between the actual propagation angle and the reference axial angle. Its value range is consistent with the effective radiation angle of the shock wave, usually from -90 degrees to 90 degrees (shock wave energy outside this range is less than 1% of the total energy and can be ignored).

[0074] Effective incident angle: the angle between the axial vector of the treatment head and the normal vector of the cortical bone surface. It represents the angle at which the shock wave is incident on the cortical bone surface under the current posture of the treatment head, and is the reference angle for judging whether energy can be easily converted into guided waves.

[0075] Relative intensity function: This refers to the ratio of the shock wave energy intensity corresponding to different angular variables to the angle of strongest energy (i.e., the effective incident angle, where the angular variable is zero). Specifically, it is calculated using a Gaussian function with the difference between the angular variable and the effective incident angle as input. The larger the difference, the smaller the relative intensity, consistent with the actual law that shock wave energy attenuates as the angle deviates from the reference direction. For example, when the difference is zero, the relative intensity is 1 (strongest energy); when the difference equals the standard deviation, the relative intensity is approximately 0.6 (energy reduced to 60% of the strongest value).

[0076] The waveguide matching angle is the critical angle at which shock wave energy is most easily converted into guided waves on the bone surface, while the main flap angle width is the range of angles where shock wave energy is most concentrated. Combining these two factors, the interval between the waveguide matching angle and half the main flap angle width represents the high-risk interval where energy is concentrated and easily converted into guided waves. Calculating the energy percentage within this interval directly determines the degree of risk of energy concentration on the bone surface under the current treatment head posture (the higher the percentage, the greater the risk).

[0077] The actual calculation of the integral is as follows: The numerical integration method is used, and the specific steps are as follows:

[0078] The first step is to determine the integration angle interval: To ensure calculation accuracy, the integration interval (whether it is the upper and lower bounds of the angular domain or the range from -90 degrees to 90 degrees) is divided into intervals of 0.1 degrees. For example, if the lower bound of the angular domain is 28 degrees and the upper bound is 32 degrees, then it is divided into 28.0 degrees, 28.1 degrees...32.0 degrees, for a total of 41 calculation points.

[0079] The second step is to calculate the relative intensity at each angle point: substitute the difference between the angle variable corresponding to each angle point and the effective incident angle into the relative intensity function to obtain the relative intensity value of that angle.

[0080] The third step is to multiply the width (0.1 degrees) of each angular interval by the relative intensity value of the midpoint of that interval, and then sum the results of all intervals to obtain the integral value of the entire interval.

[0081] The fourth step, in clinical practice, can be completed through the embedded calculation module built into the shockwave device, or by using the data processing function in regular office software (such as entering the angle points and relative intensity values ​​into a table and using the summation formula to calculate the cumulative result). The calculation accuracy needs to be controlled so that the error between the cumulative result and the analytical integral result is less than 3%.

[0082] Extensive water tank experiments have verified that over 99% of the effective energy emitted by the extracorporeal shock wave therapy head is concentrated within a range of -90 to 90 degrees from the axis of the therapy head. Energy outside this range is extremely weak, has no practical impact on the treatment effect, and does not lead to energy concentration on the bone surface. Therefore, this range is selected for calculating the total energy.

[0083] Determine the coefficients for calculating the standard deviation of the Gaussian model, including:

[0084] The energy distribution of a Gaussian distribution follows a fixed pattern: approximately 68% of the energy is concentrated within the range of the mean plus or minus one standard deviation, approximately 95% is concentrated within the range of the mean plus or minus two standard deviations, and approximately 99.7% is concentrated within the range of the mean plus or minus three standard deviations. The main lobe width of a shock wave, defined as the width between two angles when the energy drops to half its maximum value (i.e., half-width at half-maximum), has a fixed mathematical relationship with the standard deviation of the Gaussian distribution. The half-width at half-maximum equals two times the natural logarithm of 2 multiplied by the standard deviation (this coefficient is approximately 2.35). Therefore, dividing the main lobe width by this coefficient yields the standard deviation that matches the actual energy distribution of the shock wave, ensuring that the energy range calculated by the model is consistent with reality.

[0085] The relative intensity function is used to correlate the effective incident angle because during treatment, it's crucial to monitor whether energy concentrates near the waveguide matching angle under the current treatment head orientation. If the difference between the angle variable and the effective incident angle is zero, it indicates that this angle is the current incident angle of the treatment head, resulting in the strongest energy. If the difference is not zero, it means the angle deviates from the treatment head's orientation, leading to energy attenuation. By incorporating this difference into the relative intensity function, the correlation between energy intensity at different angles and the current treatment head orientation can be directly quantified, allowing for the calculation of the energy percentage within the waveguide matching angle interval.

[0086] The angular domain range is defined because if it only includes a small interval near the waveguide matching angle, other angles within the main lobe angle that are easily converted into guided waves may be missed. If the range is too large, it will include a large number of angles with weak energy, leading to distorted calculation results. The range of the waveguide matching angle plus or minus half the main lobe angle precisely covers the high-risk area where energy is most concentrated (within the main lobe) and easily converted into guided waves (around the waveguide matching angle). Calculating the energy proportion in this area can accurately determine the risk of energy concentration in the bone surface layer, avoiding misjudgment or omission.

[0087] In one embodiment of the present invention, if the angular energy percentage is higher than a preset angular energy percentage threshold, the rotation angle of the treatment head is adjusted according to the main flap angle width of the angular spectrum, and the skin translation amount is determined, so that the angular energy percentage is reduced to within the threshold and the focus remains aligned with the lesion center, including:

[0088] The effective angle of incidence after rotation is set to the sum of the effective angle of incidence before rotation and the change in the rotation angle of the treatment head;

[0089] Determine the minimum non-negative angular offset, and set the direction of the change in the treatment head rotation angle based on the relationship between the effective incident angle before rotation and the waveguide matching angle, including:

[0090] If the effective incident angle before rotation is greater than or equal to the waveguide matching angle, the change in the rotation angle of the treatment head is taken as the minimum non-negative angle offset.

[0091] If the effective incident angle before rotation is less than the waveguide matching angle, the change in the rotation angle of the treatment head is measured as the negative value of the smallest non-negative angle offset.

[0092] The angular energy percentage after rotation is calculated using a Gaussian angular distribution model, ensuring that the angular energy percentage after rotation is less than or equal to a preset angular energy percentage threshold.

[0093] The amount of skin translation is obtained by multiplying the lesion depth by the tangent of the absolute value of the change in the treatment head rotation angle.

[0094] The calculation method for the minimum non-negative angular offset includes:

[0095] The minimum non-negative angular offset is calculated based on the difference between the current angular energy percentage and the preset threshold, and the main lobe angular width of the angular spectrum.

[0096] The first step is to calculate the difference between the current angular energy percentage and the threshold using a Gaussian angular distribution model (e.g., the current percentage is 25%, the threshold is 15%, and the difference is 10%).

[0097] The second step is to determine the minimum distance that the effective incident angle needs to be far away from the waveguide matching angle by combining the main lobe width of the angular spectrum. That is, since the main lobe of the angular spectrum is the region where the energy is most concentrated, if the current effective incident angle is within the main lobe range of the waveguide matching angle, the effective incident angle needs to be deviated from the waveguide matching angle by at least half the main lobe width of the angular spectrum (e.g., if the main lobe width is 5 degrees, it needs to be deviated by at least 2.5 degrees).

[0098] The third step is to take the smallest deviation distance that reduces the proportion to within the threshold as the minimum non-negative angle offset (for example, in the above example, the proportion is exactly 15% after a deviation of 2.5 degrees, so 2.5 degrees is the minimum offset).

[0099] The operating procedures for rotating the treatment head include:

[0100] Rotation axis selection: Rotate around a horizontal axis parallel to the long axis of the patellar tendon (if the patellar tendon runs vertically, the rotation axis is horizontally to the left and right), ensuring that the treatment head is still aligned with the patellar tendon attachment area after rotation and does not deviate from the anatomical structure where the lesion is located;

[0101] Rotation accuracy control: The device uses its own angle adjustment knob, and the accuracy must reach 0.1 degrees (e.g., each turn of the knob corresponds to 0.1 degrees) to avoid exceeding the standard due to angle error; Rotation direction marking: With the front of the patient's knee as the reference, if it is necessary to reduce the effective incident angle (e.g., the effective incident angle is greater than the waveguide matching angle), the treatment head is rotated inward towards the patient (closer to the midline of the body).

[0102] If it is necessary to increase the effective angle of incidence, rotate outward (away from the body midline) and mark the inward and outward rotation scale on the outer shell of the treatment head.

[0103] The verification process for the energy percentage in the back-rotation direction adopts a small-step iterative verification method, including:

[0104] The first step is to set the initial adjustment step size to 0.5 degrees (if the proportion still exceeds the standard after adjusting by 0.5 degrees once, continue to adjust by 0.5 degrees).

[0105] The second step is to immediately recalculate the angular energy percentage using the device's built-in Gaussian model calculation module each time the rotation angle is adjusted.

[0106] The third step is to check if the proportion still does not fall below the threshold after three consecutive adjustments (cumulative 1.5 degrees). If there is an error in the ultrasound image positioning (such as deviation in the coordinate labeling of the lesion), the offset should be recalculated after correction.

[0107] Fourth step: When the calculated percentage is less than or equal to the preset threshold and the results of two consecutive verifications are consistent, stop the adjustment and determine the final rotation angle.

[0108] The operational details of skin translation include:

[0109] Translation direction determination: determined by the rotation direction. If the treatment head rotates inward (effective incident angle decreases), the focal point will shift outward towards the patient, requiring the treatment head to be translated outward; if it rotates outward, the focal point will shift inward, requiring inward translation.

[0110] Translation position marking: Before rotation, use a marker to mark a reference point on the edge where the treatment head contacts the skin (such as the intersection of the left edge of the treatment head and the skin); based on the calculated translation amount, measure the corresponding distance on the skin surface along the translation direction (such as 5 mm for a translation amount of 5 mm, then measure 5 mm outward from the reference point) and mark the new contact point.

[0111] Translation accuracy requirements: Use a millimeter-level ruler for measurement to ensure that the translation error does not exceed 0.5 mm, so as to avoid the focus deviating from the lesion due to inaccurate translation.

[0112] The preset angular energy percentage threshold setting includes:

[0113] Standard threshold value: Based on clinical trial data, the default value is 15% (that is, when the angular energy ratio is ≤15%, the risk of energy concentration in the bone surface is low).

[0114] Patient adaptation adjustment: If the patient has high bone density (such as a young patient or a patient with mild osteoporosis), the cortical bone has a stronger conductivity for guided waves, and the threshold can be reduced to 12%;

[0115] If the patient has low bone density (such as elderly patients), the threshold can be increased to 18% to avoid excessive energy restriction leading to insufficient therapeutic effect; threshold verification basis:

[0116] This threshold was validated based on treatment data from 50 patients with deep patellar tendinopathy. When the percentage is ≤15%, the probability of patients experiencing superficial bone pain is less than 5%, while the effective energy within the tendon can meet the treatment needs.

[0117] The reason for pursuing the minimum non-negative angular offset is that the larger the rotation angle of the treatment head, the greater the impact on the focusing accuracy of the shock wave (angular deviation may cause slight diffusion of the focus) and the easier it is to deviate from the core treatment area of ​​the patellar tendon attachment zone. By adjusting the minimum offset, the proportion of angular energy can be moved out of the high-risk range, while preserving the original focusing accuracy to the maximum extent, reducing unnecessary stimulation to surrounding normal tissues (such as subcutaneous fat and adjacent tendons), and balancing risk control and treatment accuracy.

[0118] The waveguide matching angle is the critical angle at which shock wave energy is most easily converted into bone surface guided waves. The closer the effective incident angle is to this angle, the higher the proportion of angular energy. Therefore, determining the direction of rotation essentially involves moving the effective incident angle away from the waveguide matching angle: if the effective incident angle before rotation is greater than the waveguide matching angle, it means the current angle is on the high-angle side of the critical angle, and rotation should be performed in the direction of decreasing angle (away from the critical angle); if it is less than the critical angle, it is on the low-angle side, and rotation should be performed in the direction of increasing angle, ensuring that each rotation accurately moves away from the high-risk zone and avoids ineffective adjustments.

[0119] The focal point of the shock wave is determined by both the axial angle and depth of the treatment head. When the treatment head rotates, the focal point's projection on the skin surface shifts (similar to the change in the spot position when a flashlight is tilted). The translation calculated by the tangent of the lesion depth multiplied by the absolute value of the rotation angle essentially compensates for this spot shift: when the lesion depth is fixed, the larger the rotation angle, the greater the shift. By translating the treatment head, the projection position of the focal point can be realigned with the lesion's projection on the skin surface, ultimately ensuring that the shock wave energy can still be precisely focused on the center of the lesion, achieving target-oriented adjustment.

[0120] Because different patients have varying cortical bone Rayleigh phase velocities and soft tissue thicknesses, the same rotation angle adjustment may result in different changes in the angular energy percentage across different patients (e.g., a 1-degree rotation in patient A may reduce the percentage by 5%, while in patient B it may only reduce it by 3%). Therefore, it is essential to calculate the percentage after rotation in real time using a Gaussian model, forming a closed loop of adjustment-calculation-verification. This avoids the problem of actual percentages exceeding the limit due to adjustments based solely on theoretical offsets, ensuring that every adjustment achieves the risk control target.

[0121] In one embodiment of the present invention, the shock wave propagation path length is calculated based on the lesion depth and the rotation angle of the treatment head. Combined with the tissue frequency attenuation coefficient and the angular energy ratio, the energy flux density is adjusted to obtain the nominal energy flux density, including:

[0122] The length of the shock wave propagation path is obtained by dividing the lesion depth by the cosine of the absolute value of the change in the rotation angle of the treatment head.

[0123] Convert the propagation path length of the shock wave to centimeters.

[0124] Convert the dominant frequency band to the dominant frequency band expressed in megahertz;

[0125] The linear attenuation coefficient is obtained by raising 10 to a negative power, which is the product of the preset tissue frequency attenuation coefficient, the dominant frequency band in megahertz, and the propagation path length in centimeters, divided by 10.

[0126] The available power share within the tendon is obtained by subtracting the angular energy share from 1.

[0127] The nominal energy flux density is obtained by dividing the set energy flux density by the product of the linear decay coefficient and the available power share within the tendon.

[0128] The determination and acquisition of the organization frequency attenuation coefficient includes:

[0129] Standard value range: Based on general data from clinical shockwave therapy, this coefficient is set to 0.5 to 0.75 dB per centimeter per megahertz by default (the higher the value, the stronger the tissue absorption of the shockwave).

[0130] Patient adaptation adjustment: If the patient has thick subcutaneous fat (ultrasound imaging shows that the fat layer is thicker than 1 cm), the coefficient is taken as the upper limit of 0.75; if the fat layer is thin and there is more muscle tissue, the lower limit of 0.5 is taken.

[0131] Acquisition method: Recommended values ​​for soft tissue frequency attenuation coefficients can be retrieved from the manufacturer's technical manual for shockwave equipment; if higher precision is required, the attenuation characteristics of the soft tissues surrounding the lesion can be measured using preoperative ultrasound equipment to directly obtain the customized coefficients for the patient.

[0132] The conversion between dominant frequency band and propagation path length includes:

[0133] Dominant frequency band conversion (Hertz to Megahertz): The dominant frequency band indicated on the equipment is usually in Hertz. To convert, divide this value by one million (since one megahertz equals one million Hertz). For example, if the dominant frequency band of the equipment is indicated as five million Hertz, it will be converted to five megahertz.

[0134] Transmission path length conversion (millimeters to centimeters): The measurement of lesion depth is usually obtained from ultrasound images and is in millimeters. When converting, divide the value by ten (because one centimeter equals ten millimeters). For example, a lesion depth of forty millimeters is converted to four centimeters.

[0135] The specific steps for calculating the linear attenuation coefficient are as follows:

[0136] The first step is to calculate the product of the three parameters: multiply the tissue frequency attenuation coefficient (e.g., 0.6 dB per centimeter per megahertz), the megahertz-level dominant frequency band (e.g., 5 MHz), and the centimeter-level path length (e.g., 4 cm) to get 0.6 × 5 × 4 = 12;

[0137] The second step is to calculate the exponent: divide the product above by 10 to get 12 ÷ 10 = 1.2;

[0138] The third step is to calculate the linear attenuation coefficient: take 10 to the power of -1.2 (i.e., 10 to the power of negative, with an exponent of 1.2), and the result is approximately 0.63 (the closer this value is to 1, the weaker the tissue's attenuation of the shock wave).

[0139] The initial criteria for determining the energy flux density are set as follows:

[0140] Baseline values: Based on the clinically recommended energy flux density range for the treatment of deep patellar tendinopathy, the initial setting is the midpoint of the range. The generally recommended range is 1.5 to 4.5 joules per square millimeter, and the default initial value is set to 3.0 joules per square millimeter.

[0141] Patient-specific adjustments: If the patient is receiving shockwave therapy for the first time and has low pain tolerance, the initial value is lowered to 2.0 joules per square millimeter; if the patient is a follow-up visit, has high tolerance and the lesion is deep, the value is increased to 4.0 joules per square millimeter.

[0142] Equipment limitations: If the calculated initial value exceeds the maximum output power density of the equipment (e.g., if the maximum is 4.0, the initial value cannot be set to 4.5), then the maximum value of the equipment shall be used as the initial value.

[0143] The accuracy control and anomaly handling of the calculation results are as follows:

[0144] Accuracy requirement: The calculation result of the nominal energy flux density should be retained to one decimal place (e.g., 3.2 joules per square millimeter) to avoid operational errors caused by too many decimal places;

[0145] Abnormal Handling (Exceeding Equipment Limit): If the calculated nominal energy flux density exceeds the maximum output value of the equipment (e.g., the maximum equipment value is 4.5, and the calculated value is 5.2), then the maximum equipment value of 4.5 is taken, and the rotation angle of the treatment head is readjusted (increasing the rotation amount to reduce the proportion of angular energy and reduce the need for backlash).

[0146] Dosage variation control: The difference in nominal energy flux density between different treatment points of the same patient shall not exceed 0.5 joules per square millimeter to avoid excessive local dose fluctuations.

[0147] Before the treatment head rotates, the shock wave propagates perpendicular to the skin, with a path length equal to the lesion depth (similar to the adjacent side of a right triangle). After rotation, the propagation direction forms an angle with the perpendicular direction (i.e., the change in rotation angle), and the path length becomes the hypotenuse of the right triangle. According to trigonometric relationships, the hypotenuse length is equal to the adjacent side (lesion depth) divided by the cosine of the angle between the adjacent side and the hypotenuse (i.e., the cosine of the absolute value of the change in rotation angle). This calculation allows for a precise determination of the actual distance traveled by the shock wave after rotation.

[0148] The attenuation characteristics of shock waves are strongly correlated with two factors: frequency (the higher the frequency, the easier it is absorbed by tissue molecules, and the stronger the attenuation), and propagation distance (the farther the distance, the more energy is absorbed, and the stronger the attenuation). Therefore, when calculating the attenuation coefficient, both frequency (megahertz-level dominant frequency band) and distance (centimeter-level path length) must be included. The tissue frequency attenuation coefficient is the attenuation per unit frequency and per unit distance. Multiplying these three factors yields the decibel value of the total attenuation. Then, by raising the value to a negative power of 10, the decibel value is converted into a linear coefficient (for subsequent energy dose calculation), thus achieving a quantitative correlation between the degree of attenuation and energy loss.

[0149] The angular energy percentage represents the portion of shock wave energy that is diverted by the cortical bone waveguide and used for propagation on the bone surface. This portion of energy cannot reach the lesion within the tendon and is considered ineffective energy loss. Therefore, the actual usable energy share within the tendon is the total energy minus the ineffective energy, i.e., 1 minus the angular energy percentage. Incorporating this share into the energy flux density backoff ensures that the final nominal value can compensate for this ineffective loss, avoiding insufficient actual energy within the tendon.

[0150] Before the shock wave reaches the lesion within the tendon, it undergoes two types of energy loss: tissue absorption loss (reflected by the linear attenuation coefficient, where energy is absorbed by tissues such as skin and fat) and guided wave energy extraction loss (reflected by the available power share within the tendon, where energy is carried away by guided waves from the bone surface). Compensating for only one type of loss will result in insufficient actual energy within the tendon (e.g., if only attenuation is compensated without guided wave energy extraction, the actual energy will be less than the extracted portion). Therefore, the effects of both types of loss need to be multiplied, and the initial set energy flux density divided by this product is used to achieve dual compensation, ensuring that the actual energy within the tendon reaches the target dose required for treatment.

[0151] In one embodiment of the present invention, treatment points are arranged along the long axis of the patellar tendon. The effective incident angle and angular energy ratio are recalculated for each treatment point. Shock waves are emitted only at treatment points where the angular energy ratio is lower than a preset angular energy ratio threshold. A treatment scheme including nominal energy flux density, treatment point position, and emission parameters is generated, including:

[0152] Establish a set of treatment point coordinates along the long axis of the patellar tendon, which includes the position of each treatment point;

[0153] For each treatment point in the set of treatment point coordinates, extract the normal vector of the cortical bone surface at that treatment point, and calculate the effective incident angle of that treatment point. The calculation method is: the inner product of the axial vector after the treatment head is rotated and the normal vector of the cortical bone surface at that treatment point, divided by the product of the length of the axial vector after the treatment head is rotated and the length of the normal vector of the cortical bone surface at that treatment point, and then take the inverse cosine value.

[0154] For each treatment point, a transmission enable variable is set. If the angular energy percentage of the treatment point is less than or equal to the preset angular energy percentage threshold, the transmission enable variable is set to 1. If the angular energy percentage of the treatment point is greater than the preset angular energy percentage threshold, the transmission enable variable is set to 0.

[0155] Calculate the number of pulses per point for each treatment point by multiplying the emission enable variable of that treatment point by the base number of pulses.

[0156] The generation scheme includes the location of each treatment point, the nominal energy flux density, the emission enable variables of each treatment point, and the number of pulses per point for each treatment point.

[0157] The number and spacing of treatment points are set, including:

[0158] Number of treatment points determined: based on the patellar tendon long axis length measured by ultrasound imaging. The typical patellar tendon long axis length is 1.5-2.5 cm, corresponding to 5-8 treatment points (the shorter the length, the fewer the points).

[0159] Spacing setting: The spacing between adjacent treatment points should be 3-5 mm (if the lesion area is relatively limited, the spacing should be reduced to 3 mm to improve coverage accuracy; if the lesion is scattered, the spacing should be increased to 5 mm) to ensure that the energy coverage of all points (the diameter of the shock wave focal zone is about 5-8 mm) can be connected without any omissions.

[0160] Details of establishing the set of treatment point coordinates include:

[0161] Location of the first and last points: The starting point is the lower pole of the patella in the ultrasound image, and the ending point is the edge of the tibial tuberosity (both are the attachment points of the patellar tendon, which are high-incidence areas of lesions).

[0162] Coordinate correspondence: Set the coordinates of the starting point in the three-dimensional coordinate system as the coordinates of the first treatment point. For each subsequent point, calculate the coordinates along the major axis at a set interval (e.g., if the starting point coordinates are X1, Y1, Z1 and the interval is 3 mm, then the next point is X1+3, Y1, Z1. It is necessary to ensure that the Z-axis (depth and superficial direction) coordinates are consistent with the lesion depth).

[0163] Coordinate recording: List all treatment point coordinates in the order of point 1, point 2... point N, and mark the corresponding anatomical location of each point (e.g., point 3: 5 mm below the inferior pole of the patella).

[0164] Extraction of the cortical bone normal vector at a single treatment point includes:

[0165] Bone surface localization: In the ultrasound slice corresponding to each treatment point, locate the cortical bone surface directly below that point (which appears as a continuous strong echo bright line).

[0166] Feature point selection: On the bone surface, select three non-collinear strong echo points (such as left, middle and right points, spaced 1-2 mm apart) around the projection position of the treatment point, and record the coordinates of the three points in the three-dimensional coordinate system;

[0167] Vector fitting: Fit the plane of the local bone surface by three-point coordinates (the plane fitting function of a regular office software can be used), and then calculate the direction perpendicular to the plane and pointing to the lesion side, which is the normal vector of the cortical bone surface at the treatment point.

[0168] The method for determining the axial vector after the treatment head rotates includes:

[0169] The final posture after the treatment head rotates by a certain angle. If the treatment head rotates inward by 2 degrees, the axial vector after rotation is the vector of the original axial vector after rotating 2 degrees around the rotation axis;

[0170] Vector update: In the three-dimensional coordinate system, the updated vector is calculated through the rotation matrix (the device's built-in attitude calculation module can complete this automatically, without manual calculation), ensuring that the vector is consistent with the actual physical axis of the treatment head;

[0171] Verification: After rotation, use an ultrasound device to observe whether the virtual extension line of the treatment head axis still passes through the lesion area. If it deviates, readjust the vector.

[0172] The reference pulse number is set as follows:

[0173] Standard range: Based on clinical data on the treatment of deep patellar tendinopathy, the baseline pulse count is set to 50-100 pulses / point by default (50 pulses for mild inflammation of the lesion, 80 pulses for moderate inflammation, and 100 pulses for severe inflammation).

[0174] Patient adaptation adjustment: If the patient is receiving treatment for the first time and has a visual analog scale (VAS) score ≥7 (severe pain), the baseline pulse count is reduced by 20% (e.g., from 80 pulses to 64 pulses); if the patient is returning for a follow-up visit and has a VAS score ≤3 (mild pain), the count is increased by 10%.

[0175] Equipment limitations: If the number of reference pulses exceeds the maximum number of output pulses per point of the equipment (e.g., the maximum number of pulses per point of the equipment is 120), then the maximum value of the equipment shall be used.

[0176] The patellar tendon is anatomically elongated, connecting the patella to the tibial tuberosity. Deep patellar tendinopathy lesions (such as tendon degeneration and calcification) are mostly distributed along the long axis, rather than scattered in arbitrary areas. Applying treatment points along the long axis ensures that the anatomical shape of the lesion matches the treatment points, allowing for precise energy coverage of the affected area. Using a conventional grid-like application method could result in non-lesion areas (such as the muscles on either side of the patellar tendon) being irradiated, increasing the risk of damage to normal tissue.

[0177] The cortical bone surfaces at different locations along the long axis of the patellar tendon are not planar (e.g., the inferior pole of the patella is arc-shaped, and the tibial tuberosity is sloping). If a single normal vector is used, it can lead to errors in the calculation of the effective incident angle at some points (the deviation may reach 5-10 degrees), thus misjudging the proportion of angular energy. Extracting a vector for each point allows the calculation of the effective incident angle to be perfectly matched with the local bone surface morphology, ensuring the accuracy of risk assessment.

[0178] An excessive angular energy ratio means that the shock wave energy at that point is easily converted into bone surface guided waves, which may cause bone pain or damage. By gating the emission enable variable to 0 / 1, the energy output of high-risk points can be directly cut off, leaving only low-risk points, thus achieving spatial risk avoidance.

[0179] The baseline pulse count is a standard value set based on the effective dose requirement within the tendon. Multiplying the emission enable variable by the baseline value ensures that the pulse count is consistent across all effective points (uniform dose), avoiding dose differences between points caused by manual adjustments. At the same time, the pulse count at ineffective points is 0, which avoids wasting energy in high-risk areas and allows limited energy to be concentrated at effective treatment points, improving efficacy.

[0180] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. A method for recommending personalized parameters for extracorporeal shock wave therapy devices based on medical data, characterized in that: include: Acquire ultrasound images of the patient with knee flexed at 20 to 30 degrees, extract the coordinates of the lesion center, the normal vector of the cortical bone surface, and the axial vector of the treatment head, and calculate the effective incident angle and lesion depth. Based on the sound velocity in soft tissue, Rayleigh phase velocity in cortical bone, effective aperture of the device, and dominant frequency band, the waveguide matching angle and the main lobe angle width of the angular spectrum are determined. An angular distribution model is used to calculate the angular energy percentage in the angular domain corresponding to the waveguide matching angle; If the angular energy percentage is higher than the preset angular energy percentage threshold, adjust the rotation angle of the treatment head according to the main flap angle width of the angular spectrum and determine the amount of skin translation so that the angular energy percentage is reduced to within the threshold and the focus remains aligned with the center of the lesion. The shock wave propagation path length is calculated based on the lesion depth and the rotation angle of the treatment head. Combined with the tissue frequency attenuation coefficient and the angular energy ratio, the energy flux density is set back to obtain the nominal energy flux density. Treatment points are arranged along the long axis of the patellar tendon. The effective incident angle and angular energy ratio are recalculated for each treatment point. Shock waves are emitted only at treatment points where the angular energy ratio is lower than the preset angular energy ratio threshold, generating a treatment scheme that includes nominal energy flux density, treatment point position and emission parameters.

2. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 1, characterized in that, Acquire ultrasound images of the patient with their knee flexed at 20 to 30 degrees. Extract the coordinates of the lesion center, the normal vector of the cortical bone surface, and the axial vector of the treatment head. Calculate the effective incident angle and lesion depth, including: Establish a three-dimensional coordinate system corresponding to the ultrasound images; Determine the coordinates of the intersection point between the skin contact surface and the axis of the treatment head; The effective angle of incidence is obtained by dividing the inner product of the treatment head axial vector and the cortical bone surface normal vector by the product of the length of the treatment head axial vector and the length of the cortical bone surface normal vector, and then taking the inverse cosine value. The lesion depth is obtained by taking the inner product of the vector obtained by dividing the axial vector of the treatment head by its own length, the vector obtained by subtracting the coordinates of the intersection point of the skin contact surface and the axis of the treatment head from the coordinates of the lesion center, and then taking the absolute value.

3. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 2, characterized in that, Based on the sound velocity in soft tissue, Rayleigh phase velocity in cortical bone, effective aperture of the device, and dominant frequency band, the waveguide matching angle and the main lobe width of the angular spectrum are determined, including: The waveguide matching angle is obtained by taking the arcsine of the quotient of the soft tissue sound velocity divided by the Rayleigh phase velocity of the cortical bone. The main lobe angular width of the angular spectrum is obtained by multiplying the constant 1.22 by the soft tissue sound velocity, and then dividing by the product of the dominant frequency band and the effective aperture of the device.

4. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 3, characterized in that, Using an angular distribution model, the angular energy percentage within the angular domain corresponding to the waveguide matching angle is calculated, including: A Gaussian angular distribution model is established. The standard deviation of the Gaussian angular distribution model is obtained by dividing the main lobe angular width of the angular spectrum by two times the natural logarithm of 2. The relative intensity function of the Gaussian angular distribution model is constructed based on the difference between the angular variable and the effective incident angle. Determine the lower and upper bounds of the angular domain corresponding to the waveguide matching angle. The lower bound of the angular domain is the waveguide matching angle minus half of the main lobe width of the angular spectrum, and the upper bound of the angular domain is the waveguide matching angle plus half of the main lobe width of the angular spectrum. Calculate the angular energy percentage, which is the integral of the relative intensity function between the lower and upper boundaries of the angular domain, divided by the integral of the relative intensity function between -90 degrees and 90 degrees.

5. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 4, characterized in that, If the angular energy percentage exceeds the preset angular energy percentage threshold, adjust the rotation angle of the treatment head according to the main flap angle width and determine the skin translation amount to reduce the angular energy percentage to within the threshold and keep the focus aligned with the lesion center, including: The effective angle of incidence after rotation is set to the sum of the effective angle of incidence before rotation and the change in the rotation angle of the treatment head; Determine the minimum non-negative angular offset, and set the direction of the change in the treatment head rotation angle based on the relationship between the effective incident angle before rotation and the waveguide matching angle, including: If the effective incident angle before rotation is greater than or equal to the waveguide matching angle, the change in the rotation angle of the treatment head is taken as the minimum non-negative angle offset. If the effective incident angle before rotation is less than the waveguide matching angle, the change in the rotation angle of the treatment head is measured as the negative value of the smallest non-negative angle offset. The angular energy percentage after rotation is calculated using a Gaussian angular distribution model, ensuring that the angular energy percentage after rotation is less than or equal to a preset angular energy percentage threshold. The amount of skin translation is obtained by multiplying the lesion depth by the tangent of the absolute value of the change in the treatment head rotation angle.

6. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 5, characterized in that, The shock wave propagation path length is calculated based on the lesion depth and the rotation angle of the treatment head. Combined with the tissue frequency attenuation coefficient and the angular energy ratio, the energy flux density is adjusted to obtain the nominal energy flux density, including: The length of the shock wave propagation path is obtained by dividing the lesion depth by the cosine of the absolute value of the change in the rotation angle of the treatment head. Convert the propagation path length of the shock wave to centimeters. Convert the dominant frequency band to the dominant frequency band expressed in megahertz; The linear attenuation coefficient is obtained by raising 10 to a negative power, which is the product of the preset tissue frequency attenuation coefficient, the dominant frequency band in megahertz, and the propagation path length in centimeters, divided by 10. The available power share within the tendon is obtained by subtracting the angular energy share from 1. The nominal energy flux density is obtained by dividing the set energy flux density by the product of the linear decay coefficient and the available power share within the tendon.

7. The method for recommending personalized parameters for an extracorporeal shock wave therapy device based on medical data according to claim 6, characterized in that, Treatment points are arranged along the long axis of the patellar tendon. The effective incident angle and angular energy ratio are recalculated for each treatment point. Shock waves are emitted only at treatment points where the angular energy ratio is lower than a preset threshold. A treatment plan is generated, including nominal energy flux density, treatment point location, and emission parameters, including: Establish a set of treatment point coordinates along the long axis of the patellar tendon, which includes the position of each treatment point; For each treatment point in the set of treatment point coordinates, extract the normal vector of the cortical bone surface at that treatment point, and calculate the effective incident angle of that treatment point. The calculation method is: the inner product of the axial vector after the treatment head is rotated and the normal vector of the cortical bone surface at that treatment point, divided by the product of the length of the axial vector after the treatment head is rotated and the length of the normal vector of the cortical bone surface at that treatment point, and then take the inverse cosine value. For each treatment point, a transmission enable variable is set. If the angular energy percentage of the treatment point is less than or equal to the preset angular energy percentage threshold, the transmission enable variable is set to 1. If the angular energy percentage of the treatment point is greater than the preset angular energy percentage threshold, the transmission enable variable is set to 0. Calculate the number of pulses per point for each treatment point by multiplying the emission enable variable of that treatment point by the base number of pulses. The generation scheme includes the location of each treatment point, the nominal energy flux density, the emission enable variables of each treatment point, and the number of pulses per point for each treatment point.

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