Microwave treatment system with multiple safety monitoring functions

Abstract

The invention relates to the technical field of microwave treatment, in particular to a microwave treatment system with multiple safety monitoring functions, which comprises a temperature field monitoring module, a standing wave detection module, an impedance analysis module, a contact state detection module, a power decision module and an emergency control module, the temperature field monitoring module generates biological tissue temperature distribution data; the standing wave detection module calculates a standing wave coefficient of a microwave transmission path; the impedance analysis module outputs an impedance change rate; the contact state detection module is combined with the impedance change rate to generate a contact safety index; the power decision module generates a dynamic power adjustment instruction; the emergency control module detects a standing wave coefficient gt; 2.5, the impedance change rate gt; 40% / s or contact safety index lt; and when 0.7, a three-level gradient braking strategy is started. According to the invention, the capability of early warning risk factors such as thermal field abnormity, energy coupling mismatch and poor contact is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave therapy, and particularly relates to a microwave therapy system with multiple safety monitoring functions. Background Art

[0002] As a common physical therapy method, microwave therapy has been widely used in medical scenarios such as tumor ablation and rehabilitation physiotherapy. It precisely heats biological tissues through microwave energy to achieve the treatment purpose. However, in the actual application process, the coupling state between microwaves and tissues, the energy transmission efficiency, and the local temperature rise situation are complex and variable. If relevant parameters cannot be monitored in time and intervened, it is extremely easy to cause treatment failure or tissue damage. Therefore, improving the dynamic perception ability of key physical states during the treatment process and establishing an effective safety prevention and control mechanism are important prerequisites for ensuring treatment safety.

[0003] Currently, some microwave therapy devices only rely on a single parameter (such as temperature or output power) for closed-loop control, lacking a joint perception and response mechanism for key factors such as standing wave reflection, tissue impedance change, and contact state. When there are problems such as abnormal reflection, impedance mismatch, or poor contact in the system, it is often impossible to identify them in time and accurately, resulting in power control delay or protection mechanism failure, increasing the possibility of risks for patients due to local overheating or energy out of control. Summary of the Invention

[0004] The present invention provides a microwave therapy system with multiple safety monitoring functions. By constructing a multi-module monitoring structure integrating temperature, standing wave, impedance, and contact state perception, it analyzes abnormal states that may occur during the microwave transmission process in real time, generates dynamic power regulation instructions based on a fusion algorithm, and when the system detects potential risks, it quickly responds through a three-level braking strategy, thereby effectively reducing the risk of tissue damage caused by abnormal physical quantities during treatment and improving the overall safety and intelligent level of the system.

[0005] A microwave therapy system with multiple safety monitoring functions includes a temperature field monitoring module, a standing wave detection module, an impedance analysis module, a contact state detection module, a power decision module, and an emergency control module, wherein;

[0006] The temperature field monitoring module generates biological tissue temperature distribution data including spatial gradient features;

[0007] The standing wave detection module receives the temperature distribution data and calculates the standing wave coefficient of the microwave transmission path based on the change in thermal dielectric constant;

[0008] The impedance analysis module fuses the standing wave coefficient and the temperature distribution data, constructs a dynamic impedance matching model, and outputs the impedance change rate;

[0009] The contact state detection module obtains the three-dimensional pressure distribution map of the treatment head and generates a contact safety index in combination with the impedance change rate;

[0010] The power decision module receives the standing wave coefficient, the impedance change rate, and the contact safety index, and generates a dynamic power adjustment instruction through a multi-parameter fusion algorithm;

[0011] When the emergency control module detects that the standing wave coefficient > 2.5, the impedance change rate > 40% / s, or the contact safety index < 0.7, it activates a three-level gradient braking strategy.

[0012] Optionally, the temperature field monitoring module includes:

[0013] Multi-directional sensing data acquisition: Through multiple groups of fiber optic temperature sensors arranged in a ring array, the circumferential temperature values of the treatment area are synchronously collected at 15° intervals, and the depth direction temperature data is obtained in combination with a near-infrared temperature measurement unit to form an original temperature data set T(θ, d), where θ ∈ [0°, 360°) represents the circumferential angle where the sensor is located, and d ∈ [0, D max represents the detection depth;

[0014] Spatial interpolation reconstruction: The bicubic spline interpolation algorithm is used to compensate for the temperature values of the missing detection points and construct a three-dimensional temperature field model;

[0015] Gradient feature extraction: Perform a spatial difference operation on the three-dimensional temperature field model, calculate the gradient components, and generate a spatial gradient vector matrix G = [G r , G θ , G z ;

[0016] Abnormal area calibration: Based on the spatial gradient vector matrix, set an abnormal criterion. When and G z < -0.5 °C / mm, it is determined as a high-temperature core area. When |G θ | > 2 °C / degree and G r < 1 °C / mm, it is determined as a marginal overheating area;

[0017] Data encapsulation and output: Perform data fusion on the three-dimensional temperature field model and the spatial gradient vector matrix, and encapsulate them into a structured data packet, including a basic temperature distribution layer (recording the temperature values corresponding to each spatial coordinate point), a gradient feature layer (recording the three-dimensional gradient vectors and abnormal area identification codes of each point), and a time stamp sequence (recording the time sequence of temperature data acquisition and evolution).

[0018] Optionally, the standing wave detection module includes:

[0019] Dielectric constant dynamic modeling: Extract the basic temperature distribution layer from the generated structured data packet to obtain three-dimensional temperature distribution data T dist (x, y, z). According to the temperature-correlation model of the dielectric properties of biological tissues, calculate the dielectric constant at each point and generate a three-dimensional dielectric constant distribution matrix [ε r (x, y, z)];

[0020] Discretization processing of the transmission path: Divide the energy transmission path of the microwave radiator into N small segments in space. The length of each microelement satisfies Δl ≤ λ / 10, where λ is the wavelength at the operating frequency. Establish a microelement attribute table including position coordinates, local dielectric constant, and temperature values;

[0021] Calculation of the reflection coefficient for each segment: For each adjacent microelement boundary, calculate the reflection coefficient Γ according to the transmission line equation n ;

[0022] Cumulative phase difference analysis: Based on the sequence of reflection coefficients, calculate the cumulative phase difference from the source end to the nth microelement

[0023] Synthesis of the standing wave ratio: Select the maximum value of the cumulative phase difference and the minimum value to calculate the standing wave ratio SWR;

[0024] Abnormal standing wave detection: When the comprehensive standing wave ratio SWR exceeds 2.5 or it is detected that the mutation of the cumulative phase difference between adjacent microelements is greater than π / 3, it is determined that there is an abnormal standing wave phenomenon in the current microwave transmission path, and then a standing wave distortion warning signal is generated.

[0025] Optionally, the impedance analysis module includes:

[0026] Spatio-temporal alignment of multi-source data: Perform timestamp matching and spatial coordinate mapping on the received standing wave ratio SWR(t) and temperature distribution data T(x, y, z, t) to establish a synchronous data set, including the temperature T c (t) at the center point of the treatment area and the maximum value of the standing wave ratio SWR max (t);

[0027] Calculation of the basic impedance: Based on the dielectric constant ε at the initial temperature T0 r0 , calculate the reference impedance Z0;

[0028] Dynamic impedance modeling: Integrate the temperature change and the influence of the standing wave to construct a time-varying impedance model;

[0029] Calculation of the impedance change rate: Use the time window differentiation method to calculate the impedance change rate When the change in the central temperature within the sampling period does not exceed 2°C, first-order difference is used. When the change in the central temperature within the sampling period exceeds 2°C, it switches to second-order difference. The sampling interval Δt is 50 milliseconds;

[0030] Dynamic threshold correction: Calculate the adaptive impedance anomaly threshold Z threshold (t) according to the fluctuation characteristics of the historical impedance;

[0031] Abnormal output: When both |Z(t) - Z0| > 0.25Z0 and the duration of the abnormal state is greater than 200 ms, an impedance anomaly signal is generated.

[0032] Optionally, the contact state detection module includes:

[0033] Three-dimensional pressure sensing: Obtain the contact pressure distribution between the treatment head and the biological tissue in real time through the sensing array, and eliminate the interference of environmental temperature drift on the pressure detection result at the same time;

[0034] Safety index fusion: Fusion the pressure distribution characteristics and the impedance dynamic change characteristics to construct a contact safety index for real-time evaluation of the treatment contact state.

[0035] Optionally, the three-dimensional pressure sensing includes:

[0036] Sensor structure design: A flexible sensing array is composed of 64 piezoresistive units arranged in a hexagonal honeycomb pattern. The size of a single sensing unit is 3 mm × 3 mm, and the pressure detection range is 0 to 20 N / cm 2 , and a double-layer isolation structure is adopted. Among them, the upper layer is a polyimide (PI)-based pressure-sensitive layer with a thickness of 50 μm, and the lower layer is a platinum resistance temperature compensation layer with a unit spacing of 0.2 mm;

[0037] Temperature drift correction: To eliminate the influence of temperature change on the pressure reading, temperature correction processing is performed;

[0038] Three-dimensional pressure map reconstruction: Use the inverse distance weighted interpolation (IDW) method to construct a continuous pressure field from discrete pressure points.

[0039] Optionally, the safety index fusion includes:

[0040] Multi-source feature extraction: Extract the maximum pressure gradient and the time slope index s of the impedance change rate dZ / dt ;

[0041] Dynamic weight assignment mechanism: Based on the extracted multi-source features, calculate the pressure feature weight w p and the impedance feature weight w z ;

[0042] Calculation of contact safety index: Based on the pressure characteristic weight w p and the impedance characteristic weight w z to generate the final contact safety index SI.

[0043] Optionally, the power decision module includes:

[0044] Normalization processing: Normalize the received standing wave ratio, impedance change rate, and contact safety index;

[0045] Dynamic weight allocation: Allocate fusion weights to the normalized standing wave ratio, impedance change rate, and contact safety index according to the current system state;

[0046] Calculation of power adjustment amount: Fuse the normalized standing wave ratio, impedance change rate, and contact safety index according to the weights to calculate the instantaneous power adjustment amount ΔP;

[0047] Time-domain smoothing processing: Use exponential filtering for output smoothing;

[0048] Safety constraint addition: Set a protective limit strategy. If SWR > 2.5 and SI < 0.7, then force power reduction, i.e., ΔP ≤ -0.1P base , ΔP ≤ -0.1P base .

[0049] Optionally, the three-level gradient braking strategy includes:

[0050] The first-level braking (power limit and primary alarm): When it is detected that the standing wave ratio > 2.5, the impedance change rate > 40% / s, or the contact safety index < 0.7, reduce the current output power to 50%, and simultaneously activate the audible and visual alarm system to emit a yellow flashing warning and an 800 Hz beeping sound to remind the operator. In this stage, maintain the basic treatment output and continuously monitor the parameter status. If it does not automatically return to the safe range (SWR ≤ 2.0, |dZ / dt| ≤ 30% / s, SI ≥ 0.8) within 10 seconds, then automatically enter the second-level braking response;

[0051] The second-level braking (deep power reduction and active cooling): If the first-level braking is ineffective, enter the second-level braking, reduce the output power to 20% of the initial set value, and start the liquid cooling circulation system to cool the treatment head at a rate of 5°C / s to inhibit the risk of temperature rise. At the same time, the system interface prompts a high-voltage risk and locks the manual power adjustment permission to prevent human misoperation intervention. If there is still a continuous abnormal state where the standing wave ratio is greater than 2.8 or the impedance change rate exceeds 50% / s within 30 seconds, then automatically enter the third-level braking;

[0052] Third-level braking (emergency cut-off and equipment locking): After confirming the continuous existence of high-voltage risks, trigger the third-level braking, completely cut off the microwave output power supply, put the equipment into a physically isolated state, eject the treatment head lock through the mechanical structure, forcibly disconnect the contact connection with the patient, then enter the self-check locking mode, record abnormal parameters to generate a fault diagnosis report, and prohibit continued use. It must be restarted by an authorized engineer through hardware reset.

[0053] Advantages of the present invention:

[0054] In the present invention, by integrating temperature field monitoring, standing wave detection, impedance analysis, and contact state recognition, real-time acquisition and high-precision analysis of multiple key safety parameters during the microwave treatment process are achieved. The system can not only construct a temperature distribution model containing spatial gradient characteristics, but also dynamically extract tissue dielectric changes, reflection characteristics, and pressure distribution states, completing a closed-loop perception from sensing to physical layer state cognition, effectively improving the early warning ability for risk factors such as abnormal thermal fields, energy coupling mismatch, and poor contact.

[0055] In the present invention, real-time power adjustment instructions are generated through standardization, dynamic weighting, and non-linear mapping methods, and combined with time-domain filtering and abnormal constraint logic, continuous, flexible, and precise regulation of the treatment power is achieved. Compared with the constant power or single-parameter control method, this method has higher response sensitivity and system robustness, significantly reducing treatment risks such as overheating and overvoltage.

[0056] In the present invention, a safety link from soft constraint to hard cut-off is constructed through a three-level gradient braking strategy. When the system monitors that the key indicators exceed the set thresholds, measures such as power limiting, cooling intervention, and physical power-off are sequentially executed, combined with functions such as alarm, interface locking, and remote log uploading, achieving full coverage of the entire process from early warning response to extreme protection. Especially in the three-level braking, a mechanical separation and engineering reset mechanism is introduced, which can completely block high-risk output, avoid patient injury and equipment damage, reflecting a highly intelligent and medical-grade safety redundancy design. Description of the drawings

[0057] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only those of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0058] Figure 1 It is a schematic diagram of the system function module of the embodiment of the present invention;

[0059] Figure 2 It is a schematic diagram of the impedance analysis module of the embodiment of the present invention. Detailed Implementation Modes

[0060] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the accompanying drawings are only for more specifically describing the embodiments, and are not intended to specifically limit the present invention.

[0061] It should be pointed out that in the specification, the mention of "an embodiment", "embodiment", "exemplary embodiment", "some embodiments", etc. indicates that the described embodiment may include specific features, structures or characteristics, but not necessarily every embodiment includes such specific features, structures or characteristics. In addition, when combining an embodiment to describe a specific feature, structure or characteristic, implementing such a feature, structure or characteristic in combination with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the relevant art.

[0062] Generally, terms can be understood at least in part from their use in context. For example, at least in part depending on the context, the term "one or more" used herein can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey a set of exclusive factors, but rather can alternatively, at least in part depending on the context, allow for the existence of other factors that may not be explicitly described.

[0063] As Figure 1 - Figure 2 shown, a microwave treatment system with multiple safety monitoring functions includes a temperature field monitoring module, a standing wave detection module, an impedance analysis module, a contact state detection module, a power decision module, and an emergency control module, where;

[0064] The temperature field monitoring module generates biological tissue temperature distribution data including spatial gradient characteristics;

[0065] The standing wave detection module receives the temperature distribution data and calculates the standing wave coefficient of the microwave transmission path based on the change in thermal dielectric constant;

[0066] The impedance analysis module fuses the standing wave coefficient and the temperature distribution data, constructs a dynamic impedance matching model, and outputs the impedance change rate;

[0067] The contact state detection module obtains the three-dimensional pressure distribution map of the treatment head and generates a contact safety index in combination with the impedance change rate;

[0068] The power decision module receives the standing wave coefficient, the impedance change rate, and the contact safety index, and generates a dynamic power adjustment instruction through a multi-parameter fusion algorithm;

[0069] When the emergency control module detects that the standing wave ratio > 2.5, the impedance change rate > 40% / s, or the contact safety index < 0.7, it activates the three-level gradient braking strategy.

[0070] The temperature field monitoring module includes:

[0071] Multi-directional sensing data acquisition: Through multiple groups of fiber optic temperature sensors arranged in a circular array, the circumferential temperature values of the treatment area are synchronously acquired at 15° intervals. Combining with the near-infrared temperature measurement unit to obtain the temperature data in the depth direction, an original temperature data set T(θ, d) is formed, where θ ∈ [0°, 360°) represents the circumferential angle where the sensor is located, and d ∈ [0, D max represents the detection depth;

[0072] Spatial interpolation and reconstruction: The bicubic spline interpolation algorithm is used to compensate for the temperature values at missing detection points, and a three-dimensional temperature field model is constructed, denoted as:

[0073] T(x, y, z);

[0074] Among them, (x, y) are the projection coordinates of the treatment area on the horizontal plane, and z is the tissue depth direction;

[0075] Gradient feature extraction: Perform spatial difference operations on the three-dimensional temperature field model, calculate the gradient components, and generate a spatial gradient vector matrix G = [G r , G θ , G z , denoted as:

[0076]

[0077] Among them, G r is the radial temperature gradient, G θ is the circumferential temperature gradient, and G z is the axial temperature gradient;

[0078] Abnormal area calibration: Based on the spatial gradient vector matrix, set the abnormal criterion. When and G z < -0.5°C / mm, it is determined as the high-temperature core area. When |G θ | > 2°C / degree and G r < 1°C / mm, it is determined as the edge overheating area;

[0079] Data encapsulation and output: Perform data fusion on the three-dimensional temperature field model and the spatial gradient vector matrix, and encapsulate them into a structured data packet, including the basic temperature distribution layer (recording the temperature values corresponding to each spatial coordinate point), the gradient feature layer (recording the three-dimensional gradient vectors and abnormal area identification codes of each point), and the timestamp sequence (recording the time sequence of temperature data acquisition and evolution).

[0080] The standing wave detection module includes:

[0081] Dynamic dielectric constant modeling: Extract the basic temperature distribution layer from the generated structured data packet, obtain the three-dimensional temperature distribution data T dist (x, y, z), and calculate the dielectric constant at each point according to the temperature correlation model of the dielectric properties of biological tissues, and generate a three-dimensional dielectric constant distribution matrix [εr(x, y, z)], which is expressed as:

[0082] ε r (T dist ) = ε r0 ·[1 + γ·(T dist - T0)];

[0083] Among them, ε r (T dist ) is the relative dielectric constant of biological tissues at temperature T dist , ε r0 is the initial dielectric constant of biological tissues at the reference temperature T0, γ is the temperature sensitivity coefficient, indicating the sensitivity of the dielectric constant to temperature changes, and T dist is the temperature distribution data;

[0084] Discretization processing of the transmission path: Divide the energy transmission path of the microwave radiator into N small segments in space, and the length of each microelement satisfies Δl ≤ λ / 10, where λ is the wavelength at the operating frequency, and establish a microelement attribute table including position coordinates, local dielectric constant, and temperature values;

[0085] Calculation of the segment reflection coefficient: For each adjacent microelement boundary, calculate the reflection coefficient Γ n , which is expressed as:

[0086]

[0087] Among them, Γ n is the reflection coefficient of the nth microelement, Z n is the characteristic impedance of the nth microelement, Z n+1 is the characteristic impedance of the (n + 1)th microelement, and μ r is the relative permeability of biological tissues;

[0088] Cumulative phase difference analysis: Based on the reflection coefficient sequence, calculate the cumulative phase difference from the source end to the nth microelement, which is expressed as:

[0089]

[0090] Among them, is the cumulative phase difference from the radiation source to the nth microelement, and arg(Γ k) is the phase angle of the reflection coefficient of the k-th microelement, α is the electromagnetic wave attenuation factor of the tissue, and d k is the normalized distance from the k-th microelement to the radiation source;

[0091] Standing wave coefficient synthesis: Select the maximum value of the cumulative phase difference and the minimum value Calculate the standing wave ratio SWR, expressed as:

[0092]

[0093] where π is the pi;

[0094] Abnormal standing wave detection: When the comprehensive standing wave ratio SWR exceeds 2.5 or the cumulative phase difference mutation between adjacent microelements is detected to be greater than π / 3, it is determined that there is an abnormal standing wave phenomenon in the current microwave transmission path, and then a standing wave distortion alarm signal is generated.

[0095] The impedance analysis module includes:

[0096] Multi-source data spatio-temporal alignment: Perform timestamp matching and spatial coordinate mapping on the received standing wave ratio SWR(t) and temperature distribution data T(x, y, z, t), and establish a synchronous data set, including the temperature T at the center point of the treatment area c (t) and the maximum value of the standing wave ratio SWR max (t), expressed as:

[0097] T c (t) = T(0, 0, 0, t);

[0098] SWR max (t) = max(SWR(t));

[0099] Basic impedance calculation: Based on the dielectric constant ε at the initial temperature T0 r0 , calculate the reference impedance Z0, expressed as:

[0100]

[0101] Dynamic impedance modeling: Integrate the temperature change and the standing wave effect to construct a time-varying impedance model, expressed as:

[0102] Z(t) = Z0·[1 + β·(T c (t) - T0)]·[1 + κ·(SWR max (t) - 1)];

[0103] where Z(t) is the dynamic impedance value (the current impedance after integrating temperature and standing wave), β is the temperature-impedance coupling coefficient (the intensity of the impedance affected by temperature), and k is the standing wave correction factor (reflecting the degree of correction of the standing wave on the impedance);

[0104] Calculation of impedance change rate: The impedance change rate is calculated using the time window differentiation method. When the central temperature change within the sampling period does not exceed 2°C, the first-order difference is used. When the central temperature change within the sampling period exceeds 2°C, it switches to the second-order difference to improve the calculation accuracy. The sampling interval Δt is 50 milliseconds, which is expressed as:

[0105]

[0106] Dynamic threshold correction: According to the fluctuation characteristics of historical impedance, calculate the adaptive impedance anomaly threshold Z threshold (t), which is expressed as:

[0107] Z threshold (t) = Z base +η·σ Z ;

[0108] Among them, Z base is the average impedance within the last 10 seconds, σ Z is the corresponding standard deviation, and η is the dynamic safety factor, which decays with time t, η(t) = 3.0 - 0.1t;

[0109] Abnormal output: When both |Z(t) - Z0| > 0.25Z0 and the duration of the abnormal state is greater than 200 ms, an impedance anomaly signal is generated.

[0110] The contact state detection module includes:

[0111] Three-dimensional pressure sensing: The contact pressure distribution between the treatment head and biological tissue is obtained in real time through the sensor array, and at the same time, the interference of environmental temperature drift on the pressure detection result is eliminated;

[0112] Safety index fusion: Fuse the pressure distribution characteristics and impedance dynamic change characteristics to construct a contact safety index for real-time evaluation of the treatment contact state.

[0113] Three-dimensional pressure sensing includes:

[0114] Sensor structure design: A flexible sensor array is composed of 64 piezoresistive units arranged in a hexagonal honeycomb pattern. The size of a single sensing unit is 3 mm × 3 mm, and the pressure detection range is 0 - 20 N / cm 2 , and a double-layer isolation structure is adopted. Among them, the upper layer is a polyimide (PI)-based pressure-sensitive layer with a thickness of 50 μm, and the lower layer is a platinum resistance temperature compensation layer with a unit pitch of 0.2 mm;

[0115] Temperature drift correction: To eliminate the influence of temperature change on the pressure reading, temperature correction is performed, which is expressed as:

[0116] P corrected = P raw ·[1 - α'(T - T0)];

[0117] Wherein, P corrected is the corrected true pressure, P raw is the original output pressure of the sensor, T is the temperature of the current contact area, and α' = 0.015 / °C is the temperature compensation coefficient;

[0118] 3D pressure map reconstruction: Using the inverse distance weighted interpolation (IDW) method, discrete pressure points are constructed into a continuous pressure field, expressed as:

[0119]

[0120] Wherein, P i is the corrected pressure value of the i-th unit, d i is the Euclidean distance between the interpolation point and the center of the i-th unit, k' = 2 is the interpolation attenuation index, and P(x, y) is the two-dimensional pressure field in the pressure distribution map.

[0121] Safety index fusion includes:

[0122] Multi-source feature extraction: Extract the maximum pressure gradient and the time slope index s of the impedance change rate dZ / dt , expressed as:

[0123]

[0124] Wherein, are the gradients of the pressure field in the x and y directions respectively;

[0125]

[0126] Wherein, s dZ / dt is the impedance change rate slope index;

[0127] Dynamic weight allocation mechanism: Based on the extracted multi-source features, calculate the pressure feature weight w p and the impedance feature weight w z , expressed as:

[0128]

[0129] Wherein, is the slope adjustment factor, and s0 is the impedance change rate discrimination threshold, set to 0.3;

[0130] Contact safety index calculation: Based on the pressure feature weight w p and the impedance feature weight w zGenerate the final contact safety index SI, expressed as:

[0131]

[0132] where σ P is the standard deviation of the current pressure distribution, P avg is the mean of the current pressure distribution, and tanh(·) is the hyperbolic tangent function.

[0133] The power decision module includes:

[0134] Normalization processing: Normalize the received standing wave ratio, impedance change rate, and contact safety index, specifically including:

[0135] (1) Standing wave ratio normalization: SWR max = 5.0;

[0136] where SWR norm is the result of standing wave ratio normalization;

[0137] (2) Impedance change rate compression mapping (nonlinear suppression):

[0138] where Z norm is the non-linear compression value of the impedance change rate;

[0139] (3) Contact safety index inverse mapping: SI norm = 1 - SI;

[0140] where SI norm is the inverse mapping of the safety index;

[0141] Dynamic weight allocation: Allocate fusion weights to the normalized standing wave ratio, impedance change rate, and contact safety index according to the current system state, specifically including:

[0142] (1) Basic weight setting: α1 = 0.5, α2 = 0.3, α3 = 0.2;

[0143] where α1, α2, and α3 are the fusion weights of the standing wave ratio, impedance change rate, and contact safety index respectively;

[0144] (2) Emergency state correction rule:

[0145] If SWR > 3.0, then: α1 ← min(0.8, α1 + 0.3);

[0146] If (i.e., 50% / s), then: α2 ← min(0.6, α2 + 0.25);

[0147] If SI < 0.6, then: α3 ← min(0.5, α3 + 0.3);

[0148] Calculation of power adjustment amount: The standing wave ratio, impedance change rate, and contact safety index after normalization are fused according to weights to calculate the instantaneous power adjustment amount ΔP, which is expressed as:

[0149] ΔP = [α1·SWR norm + α2·Z norm + α3·SI norm ·P base ;

[0150] Where, P base is the current treatment power reference value, and the adjustment limit of the instantaneous power adjustment amount ΔP is set as ΔP ∈ [-0.3P base , +0.2P base ;

[0151] Smoothing processing in the time domain: To prevent excessive power fluctuations, exponential filtering is used for output smoothing, which is expressed as:

[0152] P out (t) = P out (t - 1)+ΔP·[1 - e -t / τ ;

[0153] Where, τ is the filtering time constant, P out (t) is the final output power, and P out (t - 1) is the power output at time (t - 1);

[0154] Additional safety constraints: Set a protective limit strategy. If SWR > 2.5 and SI < 0.7, then force the power to be reduced, that is, ΔP ≤ -0.1P base , ΔP ≤ -0.1P base .

[0155] The three - level gradient braking strategy includes:

[0156] The first - level braking (power limit and primary alarm): When it is detected that the standing wave ratio > 2.5, the impedance change rate > 40% / s, or the contact safety index < 0.7, the current output power is reduced to 50%, and the audible and visual alarm system is activated synchronously, emitting a yellow flashing warning and an 800 - Hz beeping sound to remind the operator to pay attention. In this stage, the basic treatment output is maintained, and the parameter status is continuously monitored. If it does not automatically return to the safe range (SWR ≤ 2.0, |dZ / dt| ≤ 30% / s, SI ≥ 0.8) within 10 seconds, then it automatically enters the second - level braking response;

[0157] Second - stage braking (deep power reduction and active cooling): If the first - stage braking is ineffective, enter the second - stage braking. The output power is reduced to 20% of the initial set value, and the liquid - cooling circulation system is started to cool the treatment head at a rate of 5°C / s to inhibit the risk of temperature rise. At the same time, the system interface prompts the high - voltage risk and locks the manual power - adjustment permission to prevent human misoperation intervention. If there is still a continuous abnormal state where the standing - wave ratio is greater than 2.8 or the impedance change rate exceeds 50% / s within 30 seconds, it will automatically enter the third - stage braking;

[0158] Third - stage braking (emergency cut - off and equipment locking): After confirming the continuous existence of the high - voltage risk, trigger the third - stage braking, completely cut off the microwave output power supply, put the equipment into a physical isolation state, and eject the treatment - head lock through the mechanical structure to forcibly disconnect the contact connection with the patient. Subsequently, enter the self - inspection locking mode, record the abnormal parameters to generate a fault diagnosis report, and prohibit continued use. It must be restarted by an authorized engineer through hardware reset.

[0159] The present invention covers any alternatives, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention. To enable the public to have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention. However, those skilled in the art can fully understand the present invention without the description of these details. Additionally, well - known methods, processes, procedures, components, and circuits are not described in detail to avoid unnecessary confusion to the essence of the present invention.

[0160] The above - mentioned are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A microwave therapy system with multiple safety monitoring functions, characterized in that, It includes a temperature field monitoring module, a standing wave detection module, an impedance analysis module, a contact state detection module, a power decision-making module, and an emergency control module, where; The temperature field monitoring module generates biological tissue temperature distribution data including spatial gradient features; The standing wave detection module receives the temperature distribution data and calculates the standing wave coefficient of the microwave transmission path based on the thermally induced dielectric constant change; The impedance analysis module fuses the standing wave coefficient and the temperature distribution data, constructs a dynamic impedance matching model, and outputs the impedance change rate; The contact state detection module obtains the three-dimensional pressure distribution map of the treatment head and generates a contact safety index in combination with the impedance change rate; The power decision-making module receives the standing wave coefficient, the impedance change rate, and the contact safety index, and generates a dynamic power adjustment instruction through a multi-parameter fusion algorithm; When the standing wave coefficient > 2.5, the impedance change rate > 40% / s, or the contact safety index < 0.7 is detected, the emergency control module starts a three-level gradient braking strategy.

2. The microwave therapy system with multiple safety monitoring functions according to claim 1, wherein, The temperature field monitoring module includes: Multi-directional sensing data acquisition: Multiple groups of fiber optic temperature sensors arranged in a circular array synchronously collect the circumferential temperature values of the treatment area at 15° intervals, and combine with the near-infrared temperature measurement unit to obtain the temperature data in the depth direction, forming the original temperature dataset T(θ, d), where θ ∈ [0°, 360°) represents the circumferential angle where the sensor is located, and d ∈ [0, D max} represents the detection depth; Spatial interpolation reconstruction: The bicubic spline interpolation algorithm is used to compensate for the temperature values of the missing detection points, and a three-dimensional temperature field model is constructed; Gradient feature extraction: Perform a spatial difference operation on the three-dimensional temperature field model, calculate the gradient components, and generate a spatial gradient vector matrix G = [G r , G θ , G z ; Abnormal area calibration: Based on the spatial gradient vector matrix, an abnormal criterion is set. When the following conditions are met and G z <-0.5 °C / mm, it is determined as the high-temperature core area. When |G θ |>2 °C / degree and G r <1 °C / mm, it is determined as the edge overheat area; Data encapsulation and output: The three-dimensional temperature field model and the spatial gradient vector matrix are fused, and encapsulated into a structured data packet, including the basic temperature distribution layer, the gradient feature layer, and the timestamp sequence.

3. A microwave treatment system with multiple safety monitoring functions according to claim 2, characterized in that, The standing wave detection module includes: Dynamic modeling of dielectric constant: Extract the basic temperature distribution layer from the generated structured data packet to obtain three-dimensional temperature distribution data T dist (x, y, z). According to the temperature correlation model of the dielectric properties of biological tissues, calculate the dielectric constant at each point and generate a three-dimensional dielectric constant distribution matrix [ε r (x, y, z)]; Discretization processing of the transmission path: The energy transmission path of the microwave radiator is divided into N small segments in space, and the length of each microelement satisfies Δl ≤ λ / 10, where λ is the wavelength at the operating frequency, and a microelement attribute table including position coordinates, local dielectric constant, and temperature value is established; Calculation of sectional reflection coefficient: For each adjacent micro-element boundary, calculate the reflection coefficient Γ according to the transmission line equation n ; Phase difference cumulative analysis: Based on the reflection coefficient sequence, calculate the cumulative phase difference from the source end to the nth microelement SWR synthesis: Select the maximum value of the cumulative phase difference and the minimum value Calculate the standing wave ratio SWR; Abnormal standing wave detection: When the comprehensive standing wave coefficient SWR exceeds 2.5 or the cumulative phase difference mutation between adjacent microelements is detected to be greater than π / 3, it is determined that there is an abnormal standing wave phenomenon in the current microwave transmission path, and a standing wave distortion warning signal is generated immediately.

4. A microwave therapy system with multiple safety monitoring functions according to claim 3, characterized in that, The impedance analysis module includes: Multi-source data spatio-temporal alignment: Perform timestamp matching and spatial coordinate mapping on the received standing wave ratio SWR(t) and temperature distribution data T(x, y, z, t) to establish a synchronized dataset, including the temperature T at the center point of the treatment area c (t) and the maximum value of the standing wave ratio SWR max (t); Base impedance calculation: Calculate the reference impedance Z0 based on the dielectric constant ε at the initial temperature T0 r0 , and calculate the reference impedance Z0; Dynamic impedance modeling: The temperature change and the standing wave influence are fused to construct a time-varying impedance model; Calculation of impedance change rate: The time-window differential method is used to calculate the impedance change rate. When the change in the central temperature within the sampling period does not exceed 2°C, the first-order difference is used. When the change in the central temperature within the sampling period exceeds 2°C, it switches to the second-order difference. The sampling interval Δt is 50 milliseconds. Dynamic threshold correction: Calculate the adaptive impedance anomaly threshold Z(t) according to the fluctuation characteristics of historical impedance threshold (t); Abnormal output: When both of the following conditions are met |Z(t) - Z0| > 0.25Z0 and the abnormal state duration is greater than 200 ms, an impedance abnormal signal is generated.

5. A microwave therapy system with multiple safety monitoring functions according to claim 1, characterized in that, The contact state detection module includes: Three-dimensional pressure perception: The contact pressure distribution between the treatment head and the biological tissue is obtained in real time through a sensing array, and at the same time, the interference of environmental temperature drift on the pressure detection result is eliminated; Safety index fusion: The pressure distribution characteristics and the impedance dynamic change characteristics are fused to construct a contact safety index for real-time evaluation of the treatment contact state.

6. The microwave therapy system with multiple safety monitoring functions according to claim 5, characterized in that, The three-dimensional pressure perception includes: Sensor structure design: A flexible sensing array is composed of 64 piezoresistive units arranged in a hexagonal honeycomb pattern. The size of a single sensing unit is 3mm×3mm, and the pressure detection range is 0 to 20 N / cm 2 , and a double-layer isolation structure is adopted. Among them, the upper layer is a polyimide-based pressure-sensitive layer with a thickness of 50μm, and the lower layer is a platinum resistance temperature compensation layer with a unit spacing of 0.2mm; Temperature drift correction: To eliminate the influence of temperature change on the pressure reading, the temperature is corrected; Three-dimensional pressure map reconstruction: The inverse distance weighted interpolation method is used to construct the discrete pressure points into a continuous pressure field.

7. A microwave therapy system with multiple safety monitoring functions according to claim 6, characterized in that, The safety index fusion includes: Multi-source feature extraction: extract the maximum pressure gradient and the time slope index s of the impedance change rate dZ / dt ; Dynamic weight allocation mechanism: Based on the extracted multi-source features, calculate the pressure feature weight w p and the impedance feature weight w z ; Contact safety index calculation: Based on the pressure feature weight w p and the impedance feature weight w z Generate the final contact safety index SI.

8. A microwave therapy system with multiple safety monitoring functions according to claim 1, characterized in that, The power decision-making module includes: Standardization processing: The received standing wave coefficient, impedance change rate, and contact safety index are standardized; Dynamic weight assignment: According to the current system state, fusion weights are assigned to the standardized standing wave coefficient, impedance change rate, and contact safety index; Calculation of power adjustment amount: The standardized standing wave coefficient, impedance change rate, and contact safety index are fused according to the weights, and the instantaneous power adjustment amount ΔP is calculated; Time-domain smoothing processing: Exponential filtering is used for output smoothing; Safety Constraint Addition: Set a protective limit strategy. If SWR > 2.5 and SI < 0.7, then force power reduction, i.e., ΔP ≤ -0.1P base , ΔP ≤ -0.1P base .

9. A microwave treatment system with multiple safety monitoring functions according to claim 1, characterized in that, The three-level gradient braking strategy includes: First-level braking: When the standing wave ratio > 2.5, impedance change rate > 40% / s, or contact safety index < 0.7 is detected, the current output power is reduced to 50%, and the acousto-optic alarm system is synchronously activated to emit a yellow flashing warning and an 800 Hz beeping sound to alert the operator. During this stage, the basic treatment output is maintained, and the parameter status is continuously monitored. If it does not automatically return to the safe range (SWR ≤ 2.0, |dZ / dt| ≤ 30% / s, SI ≥ 0.8) within 10 seconds, the second-level braking response is automatically entered; Second-level braking: If the first-level braking is ineffective, enter the second-level braking. The output power is adjusted down to 20% of the initial set value, and the liquid cooling circulation system is started to cool the treatment head at a rate of 5°C / s to suppress the risk of temperature rise. At the same time, the system interface prompts a high-voltage risk and locks the manual power adjustment permission. If there is still a continuous abnormal state with a standing wave ratio greater than 2.8 or an impedance change rate exceeding 50% / s within 30 seconds, the third-level braking is automatically entered; Third-level braking: After confirming the continuous existence of the high-voltage risk, trigger the third-level braking, completely cut off the microwave output power supply, put the device into a physical isolation state, and eject the treatment head latch through the mechanical structure to forcibly disconnect the contact connection with the patient. Subsequently, enter the self-check locking mode, record the abnormal parameters to generate a fault diagnosis report, and prohibit continued use. It must be restarted by an authorized engineer through hardware reset.

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