Bladder function improvement method for urethral dilation

Abstract

The invention discloses a bladder function improvement system and method for urethral dilation. The system identifies tissue viscoelasticity and calculates mechanical resonance frequency on the basis of a Kelvin-VoIP model, and a dynamic pulsating expansion pressure field fitting tissue characteristics is generated through a dynamic rheology driving unit. According to the method, a mechanical electrophysiology double-frequency phase locking technology is adopted, nerve electrical stimulation is accurately anchored to the wave crest phase of mechanical pressure waves, and the synergistic interaction of tissue physical remodeling and nerve reflex arc repairing is achieved. Meanwhile, a spasm-induced fluid impedance instantaneous damping feedback mechanism is introduced into the system, and when abnormal myoelectricity is monitored, the rigidity of the system is instantaneously reduced so as to actively defend damage caused by spasm. Closed-loop control is established through quantified rheological indexes, the problems that traditional rigid expansion is large in blindness and prone to tearing are solved, and precise, intelligent and safe rehabilitation treatment of urethrostenosis is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices and rehabilitation engineering, in particular to a bladder function improvement method for urethral dilation. BACKGROUND

[0002] Urethral stricture and related bladder outlet obstruction are common and refractory diseases in urology. Clinically, urethral dilation is often used to mechanically enlarge the lumen diameter to relieve dysuria and improve bladder function. Traditional urethral dilation techniques mainly rely on metal probes (such as Van Buren probes) or high-pressure balloon catheters, and the core logic is to use rigid or semi-rigid physical force to forcibly dilate the fibrotic scar tissue.

[0003] However, the existing dilation techniques have significant limitations in treatment mechanism and safety. Traditional methods usually treat lesion tissue as a static elastic material, ignoring the complex viscoelastic characteristics of biological tissue (such as stress relaxation and creep effect). This "blind" force application method cannot match the inherent mechanical resonance frequency of the tissue, often requiring excessive static pressure to achieve dilation, and continuous high pressure load not only easily causes capillary occlusion in the tube wall, leading to ischemic reperfusion injury, but also stimulates fibroblast proliferation, resulting in a high recurrence rate of stricture.

[0004] In addition, the existing dilation devices lack a synergistic intervention mechanism at the neurophysiological level. Simple mechanical dilation often induces strong pain reflexes and protective muscle spasms in patients, and existing dilation devices, whether metal probes or inflated and locked balloons, exhibit high impedance "rigid entities" in physical properties. When the patient has an involuntary muscle spasm, the device cannot perceive and yield in compliance, and this "hard" confrontation contact easily generates shear force on the fragile urethral mucosa, causing iatrogenic urethral laceration, false passage formation, and even severe complications such as massive hemorrhage. At the same time, the current treatment process highly depends on the subjective feeling and experience judgment of the doctor, and lacks objective quantitative rheological indicators to scientifically guide the strength and termination time of dilation, resulting in poor uniformity and controllability of treatment effect. SUMMARY

[0005] The present application aims to solve the technical problems of existing urethral dilation techniques, such as static high pressure leading to tissue ischemia, mechanical laceration damage, and inability to simultaneously improve bladder nerve function. The present application proposes a bladder function improvement method for urethral dilation based on deep coupling of tissue rheology and neuroelectrophysiology.

[0006] In a first aspect of the present application, a bladder function improvement method for urethral dilation is provided.

[0007] The method associates the mechanical expansion process with the real-time neural feedback of the organism by constructing a closed-loop control system, which specifically includes the following key steps: Firstly, the system performs multi-modal tissue property identification. By acquiring the bioimpedance spectrum and mechanical compliance data of the target region of the urethra, a spectrum containing the electrical and mechanical properties of the tissue is constructed. On this basis, the system uses a viscoelastic model (such as the Kelvin-Voigt model) to regard the target tissue as a spring-damper system, and combines the measured compliance data, viscous coefficient, and equivalent coupled mass of the system to calculate the mechanical resonance frequency of the specific tissue. This frequency is the specific frequency that causes the target fibrous tissue to produce the maximum thixotropic softening effect.

[0008] Secondly, based on the calculated mechanical resonance frequency, the system generates a dynamic pulsatile expansion pressure field. This pressure field is not a constant high pressure, but is superimposed by a basic expansion pressure component and a dynamic oscillation pressure component. The basic expansion pressure component is set to maintain the baseline pressure of the expansion system in contact with the tissue, and its value is lower than the capillary occlusion pressure threshold of the target tissue, to ensure that the tissue microcirculation is perfused during the expansion process and prevent ischemic necrosis. The dynamic oscillation pressure component fluctuates at the mechanical resonance frequency, using the stress relaxation effect to soften the scar tissue, rather than through strong mechanical tearing.

[0009] At the same time, in order to realize the synchronous remodeling of neural function, the method introduces a mechanical electrophysiological dual-frequency phase locking technology. While performing dynamic expansion, the system generates a neuromodulation electrical stimulation signal, and strictly locks and synchronizes the emission timing of the signal with the phase of the dynamic pulsatile expansion pressure field. Specifically, the system monitors the real-time pressure waveform, and controls the electrical stimulation signal to be triggered only in the specific time window of the peak phase (corresponding to the maximum tissue tension and the mechanical opening state of ion channels) or the trough phase (corresponding to the blood flow perfusion recovery state) of the pressure waveform, thereby improving the efficiency of neuromodulation.

[0010] Most importantly, the method establishes a spasm-induced fluid impedance transient damping feedback mechanism. The system monitors the muscle spasm state induced by the expansion action in real time, calculates the root mean square value and change rate of the induced electromyographic signal of the urethral sphincter or pelvic floor muscles, and synthesizes a spasm index representing the real-time spasm intensity. The system adjusts the fluid impedance characteristics of the expansion system in real time based on the spasm index, establishing an inverse mapping relationship between the equivalent mechanical stiffness and the spasm index. When the spasm index is detected to exceed the preset safety threshold, the system controls the equivalent mechanical stiffness of the expansion system to decrease nonlinearly with the increase of the spasm index. This means that at the moment when the patient has a protective spasm, the expansion system can automatically "soften" to accommodate muscle contraction, thereby effectively preventing antagonistic mechanical damage through damping buffering.

[0011] As a preferred embodiment, the fluid impedance characteristics of the dilation system are adjusted by changing the rheological properties of the filling medium inside the dilation system, such as the viscosity change of magneto-rheological fluid or electro-rheological fluid under the action of an external field, or by adjusting the opening of a micro-fluidic valve to change the pressure relief resistance of the fluid.

[0012] In addition, the method also includes the quantitative determination of the treatment endpoint, by periodically monitoring the rate of change of tissue impedance and the ratio of current mechanical compliance to initial mechanical compliance, and automatically terminating output when the indicators reach the preset rehabilitation standard.

[0013] In a second aspect of the application, a system architecture is provided to implement the above method.

[0014] The system includes a multi-modal sensing module, a dynamic rheological control module, a neural coupling stimulation module, and a central closed-loop controller. The multi-modal sensing module is used to collect bioimpedance and electromyographic signals. The dynamic rheological control module is used to generate pressure waves of variable frequency and adjust the fluid stiffness. The neural coupling stimulation module is used to generate an electrical stimulation signal that is phase-locked with the pressure wave. The central closed-loop controller is responsible for executing the spasticity index calculation and damping feedback control algorithm.

[0015] The present application provides a method for improving bladder function for urethral dilation. Has the following beneficial effects: 1. The present application discards the traditional physical logic of violent dilation, and by constructing the Kelvin-Voigt viscoelastic model of the tissue and solving its mechanical resonance frequency, a dynamic pulsatile pressure wave matching the inherent properties of the tissue is applied. This resonance mechanism can induce the thixotropic softening effect of scar tissue, and use oscillatory energy to efficiently release the pathological entanglement of collagen fibers, so that effective lumen remodeling can be achieved at a lower base pressure level, thereby completely avoiding the capillary occlusion and ischemic reperfusion injury caused by high-pressure static dilation.

[0016] 2. The present application strictly anchors the neural electrical stimulation pulse in the peak phase window of the mechanical dilation wave through a unique phase-locked modulation technique. This precise synchronization in time sequence allows the electrical signal to cut in at the moment of maximum tissue tension, effectively suppressing the pain transmission and abnormal reflexes triggered thereby, while the ion channels opened by mechanical stretching enhance the penetration depth of neural regulation, achieving a synergistic effect of tissue structure repair and neural reflex arc function reconstruction.

[0017] 3. In response to the sudden muscle spasm that may occur during treatment, the application establishes a fluid impedance instantaneous damping feedback mechanism. Once the system detects an abnormal burst of induced electromyographic signals, the hydraulic system is switched from "rigid retention" to "flexible compliance" state through algorithm control, instantly reducing the system stiffness to absorb the impact energy generated by muscle contraction. This "soft" intelligent retreat strategy eliminates the rigid resistance between the instrument and the tissue, and fundamentally eliminates the risk of iatrogenic urethral tear and false passage formation.

[0018] 4. The application introduces a double endpoint judgment criterion based on the ratio of complex biological impedance spectrum and mechanical compliance, which transfers the control of treatment process from the subjective experience of doctors to the objective physical data. The system can monitor the microscopic process of the transition of tissue from viscoelastic hysteresis to elastic recovery in real time, ensure timely termination of treatment when the best tissue remodeling effect is achieved, prevent recurrence of the disease caused by insufficient expansion, avoid additional trauma caused by over-treatment, and realize the standardization of the rehabilitation process.

[0019] 5. The pressure field waveform designed by the application always maintains the basic pressure below the capillary occlusion threshold, and combines with the exponential soft start strategy to ensure that the blood oxygen supply of the urethral wall tissue is not blocked during the whole treatment process. This delicate care of the tissue microenvironment blocks the pathological pathway of fibroblast over-proliferation induced by hypoxia, significantly reducing the probability of postoperative urethral stricture recurrence from a biological mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the overall hardware architecture block diagram of the bladder function improvement system for urethral dilation of the application; Figure 2 is a structural schematic diagram of the multi-modal sensing balloon catheter tip of the application; Figure 3 is the overall flowchart of the treatment method of the application. DETAILED DESCRIPTION

[0021] Referring to the accompanying Figures 1-3 , Figure 1 is the overall architecture schematic diagram of the bladder function improvement system for urethral dilation according to an embodiment of the application. The application provides an intelligent rehabilitation system based on fluid electronic deep coupling, which serves as a hardware carrier for executing the aforementioned method steps, and aims to realize precise softening of urethral stricture lesions and synchronous remodeling of bladder nerve function through dynamic synergy of physical fields. The system mainly includes a multi-modal sensing and expansion terminal, a dynamic rheological driving unit, a nerve coupling stimulation unit, and a central closed-loop feedback controller.

[0022] Referring to the accompanying Figure 1The multi-modal sensing and expansion terminal is a core component directly implanted into the patient's body, and its main structure is a flexible catheter with a multi-chamber design. The distal end of the catheter is provided with an expandable balloon assembly, which not only bears the function of mechanical expansion, but also is an interface for biological signal interaction. The balloon wall is made of a biocompatible high-molecular material with high compliance, and the outer surface integrates a flexible microelectrode array. The microelectrode array is distributed in a matrix along the axial and circumferential directions of the balloon, and can tightly adhere to the mucosa of the urethral wall.

[0023] In a specific hardware connection, the flexible microelectrode array is connected to the external system through the micro-shielded wire in the catheter wall. These electrodes have a dual function: in the sensing mode, they act as bioimpedance sensors, used to apply a multi-frequency micro-current to the tissue and collect the voltage response to construct the complex impedance spectrum of the tissue; in the treatment mode, they act as the execution end of nerve regulation, responsible for releasing electrical stimulation signals to specific nerve receptive areas (such as the pudendal nerve afferent fiber distribution area). In addition, the balloon also integrates a high-precision micro-pressure sensor inside, which is used to monitor the hydrostatic pressure inside the balloon and the pressure fluctuations caused by external muscle contraction in real time.

[0024] The power core of the system comes from the dynamic rheological driving unit, which is connected to the balloon chamber through the fluid circuit. Unlike traditional syringe bolus or constant pressure pump, the driving unit contains a high-frequency response servo hydraulic pump and a fluid impedance modulation module. The servo hydraulic pump is configured to generate dynamic pressure waves with specific frequency, amplitude and waveform, i.e. to generate sinusoidal or pulsatile oscillation waves superimposed on the basis of static pressure. The fluid impedance modulation module is connected in series or bypass in the fluid circuit, used to control the resistance characteristics of the fluid in and out of the balloon. In a preferred embodiment, the module contains a high-speed proportional flow valve or a magnetorheological fluid control valve, which can change the equivalent cross-sectional area or fluid viscosity of the fluid passage within milliseconds, thereby achieving instantaneous adjustment of the mechanical stiffness of the system.

[0025] The nerve coupling stimulation unit is a programmable electrophysiological signal generator, whose output is connected to the microelectrode array on the catheter. The unit has a phase-synchronous interface, which maintains real-time communication with the dynamic rheological driving unit. The timing control circuit inside can read the real-time waveform data of the fluid pressure and lock the specific phase point (such as the peak or trough) of the pressure wave, on the basis of which the emission of the electrical stimulation pulse is triggered, ensuring the timing coordination of the electric field and the mechanical force field.

[0026] The central closed-loop feedback controller is the operation and control center of the whole system, which interacts with each unit mentioned above in a bidirectional data. The controller integrates a high-speed digital signal processor (DSP) inside, which is used to run the tissue property identification algorithm, the resonance frequency calculation model and the spasticity damping feedback control algorithm. It receives impedance data, pressure data and electromyography (EMG) signals from the balloon end in real time, and dynamically adjusts the pressure output instruction of the servo pump, the damping instruction of the fluid impedance modulation module and the pulse parameters of the electrical stimulation unit according to the preset control logic.

[0027] Through the physical connection and logical cooperation of the above hardware architecture, the application constructs a biophysical closed-loop system with the ability of "perception-decision-execution". The system not only can perform complex dynamic expansion actions, but also has the adaptive adjustment ability similar to the biological reflex arc, which provides the necessary physical basis and control precision for the implementation of subsequent method steps, and ensures the safety and effectiveness of the treatment process.

[0028] In this embodiment, the bladder function improvement method for urethral dilation first performs step S1, multi-modal tissue property mapping and resonance frequency determination. This step aims to distinguish the pathological tissue properties of the urethral wall at the microscopic level through physical detection means, and provide accurate frequency parameters for subsequent dynamic treatment. When the balloon catheter is placed in the urethral stenosis site, the system is first in the pre-filling state, at which time the balloon wall is in slight contact with the urethral wall but no expansion stress is generated, and the flexible microelectrode array on the balloon surface forms a stable electrochemical interface with the tissue.

[0029] Referring to the accompanying drawings Figure 2 The system starts the tissue property identification program, and the control unit applies a multi-frequency weak detection current to the contacted tissue through the microelectrode array, with the frequency range covering the low frequency region to the high frequency region. The system synchronously collects the voltage response of each electrode channel, extracts the phase difference and amplitude information using digital lock-in amplification technology, and constructs the complex bioimpedance spectrum of the target region. Since the fibrotic scar tissue has dense collagen fiber arrangement and lower intracellular fluid content, it shows significantly higher resistivity and different capacitive properties than normal mucosal tissue. The controller accurately defines the axial distribution range and depth of the scar tissue by analyzing the trajectory of the impedance spectrum on the complex plane (Cole-Cole diagram), thereby generating a visual urethral lumen tissue property map.

[0030] While acquiring the electrical properties, the system performs a mechanical compliance test. The fluid driving unit injects a small volume of pulsed fluid into the balloon, with a preset volume increment, while the high-frequency pressure sensor records the resulting step response of the balloon internal pressure. The system calculates the local tissue static mechanical compliance from the ratio of volume change to pressure change. For the regions identified as scar, the compliance values are significantly lower than normal tissue. The system spatially registers the electrical impedance data with the mechanical compliance data, eliminates errors caused by artifacts or poor contact, and locks the key lesion regions to be treated.

[0031] Based on the above-obtained tissue characteristic parameters, the system enters the resonance frequency calculation stage. In order to achieve the thixotropic softening of non-violent tearing, it is necessary to determine the specific frequency that can cause the scar fiber network to produce the largest amplitude of microscopic vibration. The present embodiment uses an improved Kelvin-Voigt viscoelastic model to describe the dynamic behavior of the lesion tissue. This model equivalent to the target urethral wall as a mechanical system composed of an elastic element and a viscous element in parallel, and considers the equivalent mass after the expansion balloon is coupled with the tissue.

[0032] The system calculates the mechanical resonance angular frequency of the target tissue according to the following formula

[0033]

[0034] In this formula, represents the equivalent elastic coefficient of the target tissue, which is derived from the inverse of the aforementioned measured mechanical compliance data, reflecting the stiffness of the scar tissue; represents the viscous coefficient of the target tissue, which reflects the energy dissipation ability of the internal fluid flow and fiber friction of the tissue, and is derived from the phase angle dispersion characteristics in the bioimpedance spectrum through a pre-set correlation algorithm; represents the equivalent coupling mass of the vibration system, which includes the mass of the balloon membrane, the mass of the fluid participating in the vibration, and the effective mass of the local tissue subjected to forced vibration. Through the above calculation, the system obtains a specific frequency value At this frequency, driving the balloon to vibrate can cause the external input mechanical energy to resonate with the natural frequency of the scar tissue, thereby inducing the largest microscopic displacement in the tissue with the smallest driving force. This microscopic displacement is sufficient to break the unstable non-covalent bond cross-linking between the old collagen fibers, and to significantly reduce the apparent viscosity of the scar tissue under shear action by using the thixotropic principle of non-Newtonian fluid, thereby realizing the softening and extension of the tissue without the need to apply static high pressure that may cause ischemic necrosis. This resonance frequency data is immediately transmitted to the dynamic rheological driving unit as the reference frequency parameter for generating a dynamic pressure field in step S2.

[0035] In this embodiment, based on the mechanical resonance frequency determined in step S1, the system proceeds to step S2, which is to generate a dynamic pulsatile distending pressure field and implement tissue rheological remodeling on the urethral target region. The core of this step is to abandon the tissue ischemic compression caused by the constant high pressure in traditional methods, and instead build a composite pressure waveform superimposed by a basic pressure holding component and a high-frequency oscillation component. The control unit sends instructions to the dynamic rheological driving unit to drive the servo hydraulic pump to output fluid pressure following a specific mathematical model. The pressure field The relationship with time is precisely controlled.

[0036] The real-time fluid pressure generated by the system Strictly follow the following control equation:

[0037] In this equation, each parameter not only has mathematical meaning, but also corresponds to specific physiological and physical functions. defined as the basic distending pressure, the setting logic is to maintain the effective mechanical adhesion of the balloon and the urethral wall, and to prevent decoupling of the balloon and the tissue during oscillation. More importantly, the value of this basic pressure is strictly limited below the occlusion pressure threshold of the target region microcirculation capillary. This setting ensures that the capillary network of the stressed tissue can remain open during the entire treatment period, especially during the trough phase of the pressure wave, allowing intermittent perfusion of oxygenated blood to the damaged tissue, thereby blocking the excessive proliferation of fibroblasts caused by ischemia-reperfusion injury.

[0038] in the equation represents the amplitude of the dynamic oscillation pressure, and is the resonance angular frequency measured for the scar tissue in the previous step. The system uses this specific frequency of mechanical waves to induce resonance effects within the fibrotic tissue. According to the principles of soft tissue rheology, when the applied shear stress frequency matches the inherent frequency of the polymer network, the non-covalent bonding (such as hydrogen bonds and Van der Waals forces) within and between collagen fiber bundles will undergo unstable dissociation. This high-frequency micro-oscillation effectively utilizes the thixotropy characteristics of non-Newtonian fluids, making the scar tissue, which originally exhibits high viscosity and solid properties, exhibit "shear thinning" phenomena, with a significant decrease in apparent viscosity as the oscillation time continues. This allows the tissue to achieve greater plastic deformation at a lower average stress level, achieving "softening" of the tissue rather than physical "tearing". To prevent the body's defensive contraction reflex from being induced by sudden mechanical stimulation, a soft start term is introduced in the control equation , which is the time constant of pressure ramping, determining the time it takes for the oscillation amplitude to increase from zero to the set value The system provides sufficient adaptation time to the neuromuscular system through this smooth loading process, avoiding transient antagonistic spasms caused by the stretch reflex, thereby improving tolerance in the early stages of treatment.

[0039] During the actual execution process, the pressure sensor within the fluid drive unit monitors the actual pressure waveform within the balloon in real time at an extremely high sampling rate and feeds it back to the control unit. The control unit employs a PID control algorithm or a fuzzy control algorithm to dynamically adjust the piston displacement of the servo pump or the valve opening of the fluid impedance modulation module to compensate for pressure attenuation caused by tissue viscoelastic creep, ensuring that the actual pressure waveform applied to the urethral wall closely tracks the aforementioned theoretical model with high fidelity. This dynamic pressure field construction method transforms the treatment process from a simple geometric expansion into a physical field-induced rearrangement of the tissue's microstructure.

[0040] In this embodiment, along with the continuous output of the dynamic pulsating expansion pressure field in step S2, the system synchronously executes step S3, namely, mechatronic dual-frequency phase-locked modulation. This step aims to establish a synergistic therapeutic mechanism by utilizing the precise temporal coupling of mechanical expansion and neuro-electrical stimulation. The neural coupling stimulation unit reads the instantaneous pressure waveform data fed back by the dynamic rheological drive unit in real time through its internal high-speed communication interface, and uses digital phase-locked loop (DLL) technology to strictly anchor the emission timing of the electrical stimulation pulses to a specific phase point of the mechanical pressure wave, thereby achieving targeted reshaping of the damaged bladder-urethral reflex arc.

[0041] System-generated neural stimulation signals The output logic is not continuous or random, but is controlled by real-time mechanical pressure. The state function of is controlled by the following formula:

[0042] In this model, The basic stimulus amplitude is determined based on the patient's pain threshold and sensory threshold. Representing a specific neural modulation carrier function, it typically employs a mid-frequency interference waveform (such as a 2kHz-4kHz carrier) to penetrate deep tissues and maximize the activation of nerve fibers. The heaviside step function, in its physical sense, sets an effective mechanical stretching threshold. The step function value is 1 only when the instantaneous expansion pressure applied by the balloon exceeds the threshold, i.e. the tissue is in an effective stretched state, allowing the electrical stimulation signal output; otherwise the function value is 0, and the system is in a silent state. This gating mechanism avoids ineffective electrical stimulation when the tissue is not sufficiently conforming or in a relaxed state.

[0043] The is a phase-synchronized pulse function, which determines the precise microsecond-level time window for electrical stimulation intervention. In the preferred embodiment of the present application, the system usually adopts a "peak-locking strategy". Specifically, when the mechanical pressure wave reaches the peak phase in its cycle (i.e. the moment when the tissue tension is the largest), the system triggers an electrical stimulation pulse. The biophysical basis of this strategy lies in the use of the property of mechanosensitive ion channels on the cell membrane. At the peak phase, the urethral wall and sphincter cell membranes are at the maximum tension state, the mechanosensitive ion channels are physically open, and the membrane potential depolarization threshold is significantly reduced. At this time, superimposing an electrical stimulation signal can induce a stronger nerve action potential with lower energy input, achieving the sensitization of mechanical energy to electrophysiological effect. In addition, this nerve stimulation signal directly acts on the pudendal nerve afferent fibers under the urethral mucosa through the microelectrode array on the surface of the catheter. These phase-modulated signals are transmitted up the neural pathway to the sacral micturition center (S2-S4 segments), and the excitability of the reflex arc is adjusted through the principle of neural plasticity. The system can adjust the encoding mode of the carrier function according to different clinical symptoms. For example, for patients with detrusor weakness, the stimulation signal is encoded as a waveform that induces motor neuron excitation to enhance bladder contraction; for patients with detrusor instability, the signal is encoded as an inhibitory frequency to block abnormal spinal reflexes. In this way, the present application transforms the simple physical expansion process into an active neurorehabilitation process by deeply integrating the mechanosensation of mechanical expansion with exogenous electrical stimulation.

[0044] In this embodiment, the system is in a full-time safety monitoring state during the execution of the above-mentioned dynamic expansion and neuroregulation steps, and step S4, i.e. the spasm-induced fluid impedance instantaneous damping feedback control, is executed in the background in parallel. This step constitutes the active defense mechanism of the core of the present application, and its fundamental purpose is to solve the technical problem that the traditional rigid dilator cannot cope with the patient's involuntary muscle spasm, resulting in iatrogenic urethral laceration. The system is no longer a passive force application tool, but an intelligent entity that can perceive the biological body's countermeasures and adjust its physical properties in real time.

[0045] In the monitoring phase, the system utilizes the multiplexing function of the balloon surface microelectrode array or dedicated electromyographic sensing channels to collect the evoked myoelectric signals (EMG) of the urethral sphincter and pelvic floor muscles in real time at a high sampling rate (usually higher than 1 kHz). After band-pass filtering and notch processing to remove motion artifacts and power frequency interference, the raw signals are transmitted to the signal processing unit of the central controller. Instead of simply relying on the amplitude of the myoelectric signal, the processor uses a multi-dimensional feature fusion algorithm to quantify the severity of the spasm. The system calculates the spasm index in real time according to the following formula

[0046]

[0047] In this computational model, is the root mean square value of the myoelectric signal, representing the instantaneous intensity of muscle contraction; is the first-order derivative of this value with respect to time, representing the burst rate of muscle contraction. and are weight coefficients used to balance the contributions of the intensity term and the rate term. The physical significance of introducing the change rate term is that the system can identify those sudden and potentially destructive spasms that have not yet reached the extreme value but are rising extremely fast, thereby achieving predictive early intervention.

[0048] Once the calculated spasm index exceeds the system's preset safety threshold , the closed-loop controller immediately triggers the fluid impedance damping mechanism. The core strategy of this mechanism is to establish a reverse mapping relationship between the bioelectric signal and the mechanical system stiffness. The control unit adjusts the fluid control hardware (such as changing the excitation current of the magnetorheological fluid or adjusting the discharge opening of the microfluidic proportional valve) according to the real-time spasm intensity, dynamically modifying the equivalent mechanical stiffness of the balloon system.

[0049] The stiffness adjustment follows the following nonlinear decay model:

[0050] In the formula, represents the nominal working stiffness in the treatment state, i.e., the hardness required to maintain effective expansion. is the damping response gain coefficient, is the nonlinear response exponent (usually set to . According to this model, when a spasm occurs and the intensity exceeds the threshold, the denominator term will increase exponentially, causing the system stiffness to drop sharply within milliseconds.

[0051] In physical implementation, if the system uses magneto-rheological fluid as filling medium, the controller will cut off or reverse the magnetic field to make the fluid change from solid-like state (high yield stress) to liquid state (low viscosity) instantly, and the balloon will become soft; if the system uses hydraulic valve control system, the controller will open the fast pressure relief valve to reduce the fluid resistance of the circuit. This instantaneous "softening" or "unloading" action enables the balloon to deform in the direction of muscle spasm, converting the opposing shear force on the fragile urethral wall into fluid internal energy dissipation or volume displacement.

[0052] Through this mechanism, the invention realizes a "biological reverse control machine" logic: when the organism sends a pain or rejection signal (spasm), the mechanical system automatically retreats. As the spasm subsides, i.e. falls below the threshold, the denominator gradually returns to 1, and the system control stiffness smoothly rises to , and continues to perform the unfinished dynamic expansion task. This adaptive damping feedback loop ensures that the treatment process is always within the physiological tolerance limit of the tissue, fundamentally eliminating the risk of violent expansion.

[0053] In this embodiment, as the treatment progresses, the system periodically performs step S5, i.e. efficacy evaluation and treatment endpoint determination. This step constitutes the exit of the entire closed-loop control logic, aiming to replace the traditional empirical "feeling" judgment with quantitative rheological indicators, thereby ensuring that the treatment not only achieves the expected tissue remodeling effect, but also avoids the risk of additional damage caused by over-treatment. The system adopts an intermittent cycle evaluation strategy. During the dynamic pulsatile expansion and continuous execution of nerve regulation, every time the preset time window is reached, the control unit will automatically pause the high-frequency oscillation output, and the balloon pressure will be temporarily maintained at the basic pressure level, so as to perform high signal-to-noise ratio parameter re-measurement under quasi-static conditions.

[0054] During the evaluation window period, the multi-modal sensing terminal re-executes a detection procedure similar to step S1. The system transmits multi-frequency detection signals to the contacted tissue, and obtains the current complex bioimpedance spectrum in real time, and at the same time calculates the current mechanical compliance through a small pressure volume disturbance test. The control unit compares these real-time acquired data with the baseline data recorded at the beginning of treatment (initial impedance and initial compliance ) for comparison analysis. The core of the system is to focus on the evolution trend of the tissue physical properties, especially the transition from viscoelastic hysteresis state to elastic recovery state. In order to scientifically determine the treatment endpoint, the present application establishes a double termination criterion based on "rheological saturation" and "functional improvement". The control unit calculates the rate of change of tissue impedance over time and the gain ratio of current compliance relative to the initial state in real time. The system determines the end of treatment logic strictly follows the following inequality group:

[0055] The first condition characterizes the saturation of tissue remodeling. When the rate of change of impedance (i.e. the derivative modulus of impedance spectrum on the time axis) is less than the preset minimum value , it indicates that the thixotropic softening effect of scar tissue has reached the limit under the current physical conditions, and the unwinding process of collagen fibers has tended to be balanced, and continuing to apply oscillation will no longer produce significant rheological benefits. The second condition characterizes the physical improvement of function. Only when the mechanical compliance of the urethral wall is improved by more than the preset clinical effective threshold , it is considered to have reached the physical goal of expansion.

[0056] The first condition characterizes the saturation of tissue remodeling. When the rate of change of impedance (i.e. the derivative modulus of impedance spectrum on the time axis) is less than the preset minimum value , it indicates that the thixotropic softening effect of scar tissue has reached the limit under the current physical conditions, and the unwinding process of collagen fibers has tended to be balanced, and continuing to apply oscillation will no longer produce significant rheological benefits. The second condition characterizes the physical improvement of function. Only when the mechanical compliance of the urethral wall is improved by more than the preset clinical effective threshold , it is considered to have reached the physical goal of expansion. Only when the above two conditions are met at the same time, the central control unit will issue a termination instruction. At this time, the dynamic rheological driving unit is not suddenly unloaded, but performs a controlled pressure decay program, slowly reducing the balloon pressure to zero in an exponential law, in order to prevent reperfusion injury or rebound hemorrhage caused by sudden filling of the vascular bed. Subsequently, the system automatically saves the whole process data of the treatment, including the resonance frequency parameter, the number of spasm triggers and the compliance change curve, providing traceable data support for formulating subsequent rehabilitation plans. This automatic endpoint determination mechanism transfers the decision-making power of treatment from subjective experience to objective biophysical data, realizing the standardization and precision of the rehabilitation process.

Claims

1. A method for improving bladder function for urethral dilation, characterized by, The method comprises the following steps: Step S1: Obtain the bioimpedance spectrum and mechanical compliance data of the target region of the urethra, construct a tissue characteristic map based on the data, and calculate the mechanical resonance frequency of the target tissue; Step S2: Generate a dynamic pulsating expansion pressure field based on the mechanical resonance frequency, and perform dynamic expansion on the target region of the urethra using an expansion system; Step S3: While performing dynamic expansion, generate a neuromodulation electrical stimulation signal, and lock the emission timing of the neuromodulation electrical stimulation signal with the phase of the dynamic pulsating expansion pressure field; Step S4: Real-time monitor the muscle spasm state induced by expansion, and adjust the fluid impedance characteristics of the expansion system in real time according to the muscle spasm state; when it is detected that the muscle spasm state exceeds a preset threshold, reduce the equivalent mechanical stiffness of the expansion system to achieve damping buffering.

2. The method of claim 1, wherein, In step S1, the calculation of the mechanical resonance frequency of the target tissue specifically comprises: Based on the Kelvin-Voigt viscoelastic model, the target tissue is regarded as a spring-damping system; The equivalent elastic coefficient of the target tissue is derived using the measured mechanical compliance data, and the angular frequency that causes the target tissue to produce the maximum thixotropic softening effect is calculated by combining the viscous coefficient of the target tissue and the equivalent coupled mass of the expansion system, which is taken as the mechanical resonance frequency.

3. The method of claim 1, wherein, In step S2, the dynamic pulsating expansion pressure field is formed by superimposing a basic expansion pressure component and a dynamic oscillation pressure component; The basic expansion pressure component is set as a reference pressure that maintains the contact between the expansion system and the tissue; The dynamic oscillation pressure component is a sinusoidal wave with the mechanical resonance frequency, and includes a pressure climbing process that changes over time to achieve soft start.

4. The method of claim 1, wherein, In step S3, the phase lock synchronization specifically refers to: Monitoring the real-time pressure waveform of the dynamic pulsating expansion pressure field; Controlling the neuromodulation electrical stimulation signal to be triggered only in a specific time window when the real-time pressure waveform is at a peak phase or a valley phase; Wherein, the peak phase corresponds to the maximum state of tissue tension, and the valley phase corresponds to the blood flow perfusion recovery state.

5. The method of claim 1, wherein, In step S4, the monitoring of the muscle spasm state induced by expansion specifically comprises: Collecting the induced electromyographic signal of the urethral sphincter or pelvic floor muscle group; Calculating the root mean square value of the induced electromyographic signal and the rate of change of the root mean square value over time; Weighted sum of the root mean square value and the rate of change to obtain a spasm index representing the real-time spasm intensity.

6. The method of claim 5, wherein, In step S4, the real-time adjustment of the fluid impedance characteristics of the expansion system according to the muscle spasm state specifically comprises: Establishing an inverse mapping relationship between the equivalent mechanical stiffness of the expansion system and the spasm index; When the spasm index is less than or equal to a preset safe spasm threshold, control the expansion system to maintain the nominal working stiffness; When the spasm index is greater than the safe spasm threshold, control the equivalent mechanical stiffness of the expansion system to decrease nonlinearly with the increase of the spasm index, so that the expansion system is temporarily softened to conform to muscle contraction.

7. The method of claim 6, wherein, The fluid impedance characteristics of the regulating expansion system are achieved by changing the rheological properties of the internal filling medium of the expansion system, which is a magneto-rheological fluid or an electro-rheological fluid, and the viscosity of the medium is changed by adjusting the strength of the external field; Or, by adjusting the opening of the micro-fluidic valve to change the pressure relief resistance of the fluid.

8. The method of claim 1, wherein, The step S1 further includes distinguishing normal mucosa tissue from fibrotic scar tissue: By comparing the differences in complex impedance values under different frequency bands, combined with mechanical compliance data, the area with high resistivity and low compliance is identified as fibrotic scar tissue, and the mechanical resonance frequency is set for this area.

9. The method of claim 1, wherein, In step S2, the value of the basic expansion pressure component is set to be lower than the target tissue capillary occlusion pressure threshold, so as to maintain the tissue microcirculation perfusion in the expansion period.

10. The method of claim 1, wherein, The method further includes step S5: Periodically monitor the tissue impedance change rate and the ratio of the current mechanical compliance to the initial mechanical compliance; When the tissue impedance change rate tends to be stable and the ratio reaches the preset rehabilitation index, the output of the dynamic pulsatile expansion pressure field is automatically terminated.

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