Electrical stimulation device and method for hemiplegic foot drop gait correction

Abstract

The application discloses a kind of electric stimulation device and electric stimulation method for hemiplegic foot drop gait correction, it is related to medical instrument technical field;The electric stimulation method includes the following steps: step S10: obtaining the healthy side quadriceps femoris of healthy side and the healthy side tibialis anterior muscle of healthy side myoelectric signal;Step S20: obtaining the initial effective stimulation threshold of affected side;Step S30: obtaining the affected side quadriceps femoris of affected side and the affected side tibialis anterior muscle of affected side myoelectric signal;Step S40: obtaining the stimulation delay between the affected side quadriceps femoris and the affected side tibialis anterior muscle in each second core coordination phase of affected side;Step S50: dynamically adjusting the stimulation intensity of affected side tibialis anterior muscle;Step S60: according to the stimulation delay and the stimulation intensity, electric stimulation is carried out on the tibialis anterior muscle of affected side in each second core coordination phase.The technical scheme provided by the application can realize individuality and physiological gait correction.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an electrical stimulation device and method for gait correction of hemiplegic foot drop. Background Technology

[0002] Traumatic brain injury (such as stroke, traumatic brain injury, post-brain tumor surgery, etc.) often leads to hemiplegia in patients. Most of these patients retain a high degree of hip and knee joint function, but their ankle dorsiflexion function is severely impaired, causing foot drop, which in turn leads to a significant decrease in walking stability and an increased risk of falls. Therefore, gait correction for hemiplegic patients with foot drop is a key issue that urgently needs to be addressed in clinical rehabilitation.

[0003] Currently, the mainstream non-surgical intervention method for foot drop gait correction in clinical practice is to use an electrical stimulation device for functional electrical stimulation. The electrical stimulation device uses low-frequency pulsed current (1~100Hz) to stimulate the target muscle (tibialis anterior muscle on the affected side) and induces functional movement through a preset program.

[0004] In the existing technology, the electrical stimulation device has the following defects: 1) The stimulation delay and stimulation intensity of the low-frequency pulse current are both artificially preset fixed values, which do not take into account the differences in the basic gait between different patients, nor do they take into account the different ratios of the healthy side and the affected side of the same patient; 2) The affected side tibialis anterior muscle is only stimulated once in a single gait cycle, completely ignoring the multiple core synergistic relationships between the quadriceps femoris and the tibialis anterior muscle at different stages of normal gait, resulting in a stiff and non-physiological gait after correction.

[0005] It should be noted that the above content is only used to help understand the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main objective of this invention is to propose an electrical stimulation device and method for gait correction of hemiplegic foot drop, aiming to achieve gait correction that is both individualized and physiological.

[0007] To achieve the above objectives, this invention proposes an electrical stimulation method for gait correction in hemiplegic foot drop; specifically, the electrical stimulation method includes the following steps: Step S10: Obtain the electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; calculate the duration T1 of the healthy side gait cycle based on the electromyographic signals of the healthy side, and select at least two first core synergy phases within the healthy side gait cycle, and record the electromyographic amplitude ratio R1, muscle contraction sequence, and muscle contraction time difference Δt1 of the healthy quadriceps femoris and tibialis anterior muscle in each first core synergy phase; Step S20: Obtain the initial effective stimulation threshold I0 on the affected side; Step S30: Obtain the electromyographic (EMG) signals of the quadriceps femoris and tibialis anterior muscles on the affected side; calculate the duration T2 of the gait cycle on the affected side based on the EMG signals, and select at least two second core synergy phases within the gait cycle on the affected side, and record the ratio R2 of the EMG amplitude of the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergy phase; wherein the second core synergy phase corresponds to the first core synergy phase; Step S40: Calculate the gait cycle proportionality coefficient K, where K = T2 / T1; and based on the gait cycle proportionality coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and the tibialis anterior muscle on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K. Step S50: Calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0. Step S60: Based on the stimulation delay and the stimulation intensity, electrically stimulate the tibialis anterior muscle on the affected side during each second core synergistic phase.

[0008] In one embodiment, the electrical stimulation method is configured with three first core coordination phases, which correspond to the early support phase, the early swing phase, and the late swing phase, respectively. The early support phase corresponds to the heel-to-full-foot weight-bearing phase, the early swing phase corresponds to the toe-to-step phase, and the late swing phase corresponds to the heel-to-ground preparation phase.

[0009] In one embodiment, step S20 includes the following steps: Step S21: Gradually output pulse current to the tibialis anterior muscle on the affected side according to the current intensity from low to high, while requiring the patient to voluntarily complete ankle dorsiflexion until the patient's ankle joint dorsiflexion angle reaches or exceeds 90°. Step S22: Record the current intensity of the current output pulse current as the initial effective stimulation threshold I0.

[0010] In one embodiment, step S50 includes the following steps: Step S51: During the affected side training phase, continuously acquire the electromyographic signals of the affected quadriceps femoris and tibialis anterior muscles on the affected side; record the actual electromyographic amplitude ratio Ri of the affected quadriceps femoris and tibialis anterior muscles in each second core synergy phase based on the electromyographic signals of the affected side. Step S52: Calculate the actual muscle strength deficit difference ΔRi, where ΔRi = R1 - Ri; Step S53: Obtain the actual stimulus intensity Ii, where Ii = I0 * (ΔRi / ΔR).

[0011] In one embodiment, after step S60, the following step is further included: Step S70: After continuously executing the preset training cycles from step S30 to step S60, re-execute step S10 to update the gait cycle duration T1 of the healthy side, the electromyographic amplitude ratio R1 of the healthy quadriceps and the healthy tibialis anterior, and the muscle contraction time difference Δt1, and re-execute step S20 to update the initial effective stimulation threshold I0. Step S80: Overwrite the original parameters with the updated parameters, and return to execute steps S30 to S60.

[0012] In one embodiment, the preset training period is configured to be 1 to 2 weeks.

[0013] To achieve the above objectives, the present invention proposes an electrical stimulation device for gait correction in hemiplegic foot drop, used to perform the electrical stimulation method described above; specifically, the electrical stimulation device includes: A dual-channel electrode unit is used to acquire electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; to acquire electromyographic signals of the affected quadriceps femoris and tibialis anterior muscle on the affected side; and to perform electrical stimulation on the affected tibialis anterior muscle in each second core synergistic phase according to the stimulation delay and the stimulation intensity. The main control unit is electrically connected to the dual-channel electrode unit; the main control unit includes: The gait cycle calculation module is used to calculate the duration T1 of the gait cycle on the healthy side based on the electromyographic signal on the healthy side; and to calculate the duration T2 of the gait cycle on the affected side based on the electromyographic signal on the affected side. The collaborative timing identification module is used to record the electromyographic amplitude ratio R1 of the healthy quadriceps femoris and the healthy tibialis anterior muscle, the muscle contraction sequence, and the muscle contraction time difference Δt1 in each of the first core collaborative phases; and to record the electromyographic amplitude ratio R2 of the affected quadriceps femoris and the affected tibialis anterior muscle in each of the second core collaborative phases. An adaptive calculation module is used to calculate the gait cycle proportional coefficient K, where K = T2 / T1; and based on the gait cycle proportional coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K; and calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0.

[0014] In one embodiment, the dual-channel electrode unit includes at least two sets of electrodes, each set of electrodes having electromyographic signal acquisition and electrical stimulation output functions; the electrodes are fixed to the lateral quadriceps femoris, the contralateral tibialis anterior muscle, the affected quadriceps femoris, and the affected tibialis anterior muscle by means of flexible bandages or adhesive patches.

[0015] In one embodiment, the electrical stimulation device further includes: The electromyography (EMG) signal processing module is used to filter, amplify, and analyze the EMG signals from both the healthy and affected sides. And / or, a time-division multiplexing control module is used to control the shutdown of the electromyography signal acquisition channel during pulse current output and to immediately restore the electromyography signal acquisition function after the electrical stimulation is completed.

[0016] In one embodiment, the electrical stimulation device includes a power supply unit, which is electrically connected to the dual-channel electrode unit and the main control unit; the power supply unit has a built-in overvoltage and overcurrent protection circuit, supports a low battery reminder function, and has a battery life of ≥8 hours.

[0017] The technical solution of this invention, on the one hand, obtains the gait cycle duration T1 of the healthy side, the muscle contraction time difference Δt1, and the real-time gait cycle duration T2 of the affected side, calculates the gait cycle proportionality coefficient K=T2 / T1, and dynamically calculates the stimulation delay of the affected side based on Δt2=Δt1×K. Simultaneously, by recording the electromyographic amplitude ratio R1 of the healthy side and the electromyographic amplitude ratio R2 of the affected side, it calculates the muscle weakness difference ΔR=R1-R2 and dynamically adjusts the stimulation intensity of the tibialis anterior muscle on the affected side according to ΔR and the initial effective stimulation threshold I0. This achieves dual dynamic adaptive stimulation delay and intensity, solving the problems of manually preset fixed values ​​for stimulation parameters in existing technologies, and lack of... This approach addresses the differences in basic gait among patients and the ratio of gait cycles between the healthy and affected sides. On the other hand, it selects at least two corresponding core synergistic phases (the first and second core synergistic phases) within the gait cycles of both the healthy and affected sides, and electrically stimulates the tibialis anterior muscle on the affected side during each core synergistic phase. This overcomes the limitations of existing techniques that rely on single stimulation within a single gait cycle, restoring the multiple core synergistic relationships between the quadriceps and tibialis anterior muscles at different gait stages during normal walking. This results in a more natural and fluid gait after correction, avoiding stiffness. The combination of these two approaches achieves gait correction that is both individualized and physiologically sound. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the steps of an embodiment of the electrical stimulation method provided by the present invention. Figure 2 This is a schematic diagram of an embodiment of the electrical stimulation device provided by the present invention.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a portion of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, it should be noted that the descriptions involving "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0024] In the existing technology, the electrical stimulation device has the following defects: 1) The stimulation delay and stimulation intensity of the low-frequency pulse current are both artificially preset fixed values, which do not take into account the differences in the basic gait between different patients, nor do they take into account the different ratios of the healthy side and the affected side of the same patient; 2) The affected side tibialis anterior muscle is only stimulated once in a single gait cycle, completely ignoring the multiple core synergistic relationships between the quadriceps femoris and the tibialis anterior muscle at different stages of normal gait, resulting in a stiff and non-physiological gait after correction.

[0025] To address the aforementioned technical problems, this invention proposes an electrical stimulation method for gait correction in hemiplegic foot drop.

[0026] Please see Figure 1In one embodiment of the present invention, the electrical stimulation method includes the following steps: Step S10: Obtain the electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; calculate the duration T1 of the healthy side gait cycle based on the electromyographic signals of the healthy side, and select at least two first core synergy phases within the healthy side gait cycle, and record the electromyographic amplitude ratio R1, muscle contraction sequence, and muscle contraction time difference Δt1 of the healthy quadriceps femoris and tibialis anterior muscle in each first core synergy phase; In the above steps, electromyographic (EMG) signals generated by the healthy quadriceps and tibialis anterior muscles during walking are collected. The quadriceps is responsible for knee extension control, and the tibialis anterior is responsible for ankle dorsiflexion control; their coordinated activity constitutes a key element of normal gait. After collecting continuous healthy-side EMG signals, the system identifies and calculates the duration of a complete healthy-side gait cycle, denoted as T1. This parameter represents the patient's normal walking rhythm. Subsequently, the system selects at least two primary core synergistic phases within the entire healthy-side gait—the key periods during which the quadriceps and tibialis anterior muscles functionally coordinate during normal walking. For each selected first core synergistic phase, the system further records specific parameters in three dimensions: first, the electromyographic amplitude ratio R1, which is the ratio of the electromyographic signal intensity of the healthy quadriceps femoris to that of the healthy tibialis anterior muscle in that phase, reflecting the relative force exertion ratio of the two muscles at that moment; second, the muscle contraction sequence, i.e., the order in which the quadriceps femoris and tibialis anterior muscles are activated; and third, the muscle contraction time difference Δt1, i.e., the specific time interval from the start of contraction of the first-activated muscle to the peak contraction of the second-activated muscle, used to quantify the precise time difference of the synergistic cooperation between the two muscles. Through this step, the system transforms the normal walking pattern exhibited by the patient's healthy side into a set of quantifiable and reusable mathematical parameters (T1, R1, Δt1 and their corresponding temporal relationships), thereby establishing a highly individualized physiological benchmark template for subsequent precise electrical stimulation correction of the affected side.

[0027] Step S20: Obtain the initial effective stimulation threshold I0 on the affected side; Step S30: Obtain the electromyographic (EMG) signals of the quadriceps femoris and tibialis anterior muscles on the affected side; calculate the duration T2 of the gait cycle on the affected side based on the EMG signals, and select at least two second core synergy phases within the gait cycle on the affected side, and record the ratio R2 of the EMG amplitude of the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergy phase; wherein the second core synergy phase corresponds to the first core synergy phase; In the above steps, after establishing the healthy side baseline template and calibrating the initial effective stimulation threshold, electromyographic (EMG) signals generated by the affected quadriceps femoris and tibialis anterior muscles during walking are acquired. Similar to the healthy side processing logic, the system first identifies and calculates the duration of a complete affected side gait cycle from the acquired EMG signals, denoted as T2. This parameter reflects the patient's current real-time walking rhythm on the affected side. Subsequently, the system selects at least two second core synergistic phases within the affected side gait cycle, which maintain a one-to-one correspondence with the previously selected first core synergistic phases in gait phase. For each selected second core synergistic phase, the system records the EMG amplitude ratio R2 of the affected quadriceps femoris and tibialis anterior muscles during that phase, i.e., the ratio of the EMG signal intensity of the affected quadriceps femoris to that of the affected tibialis anterior muscle. The technical significance of this step lies in the following: By collecting the electromyographic amplitude ratio parameters (R1 and R2) of the healthy and affected sides at the same patient and gait phase position, respectively, R1 on the healthy side represents the force ratio that the two muscles should have under normal conditions, while R2 on the affected side represents the actual force ratio exhibited by the affected side at present. The difference between the two, ΔR = R1 - R2, quantitatively reflects the degree of functional deficit of the tibialis anterior muscle on the affected side, providing a core basis for the dynamic calculation of the stimulation intensity that needs to be compensated in subsequent steps. At the same time, the gait cycle duration T2 on the affected side will be used together with the cycle duration T1 on the healthy side to calculate the gait cycle proportionality coefficient K = T2 / T1, thereby realizing the dynamic scaling of stimulation delay. In short, this step completes the data acquisition and in-phase alignment from the standard of the healthy side to the current state of the affected side, laying the data foundation for subsequent two-parameter adaptive calculation.

[0028] Step S40: Calculate the gait cycle proportionality coefficient K, where K = T2 / T1; and based on the gait cycle proportionality coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K; wherein, the stimulation delay can be understood as including the inherent time interval required for the two muscles to start sequentially and complete the movement in synergy (i.e., including muscle contraction sequence and muscle contraction time difference information). The core of the above steps lies in achieving individualized dynamic adaptation of stimulus timing through gait time-domain scaling. Specifically, during normal walking, there is a fixed synergistic time relationship between the quadriceps and tibialis anterior muscles—that is, the muscle contraction time difference Δt1 recorded on the healthy side. Because the affected side of a hemiplegic patient has impaired neural control, their walking speed is often significantly slower than the healthy side, manifested as a proportional difference between the gait cycle duration T2 of the affected side and the gait cycle duration T1 of the healthy side. This invention quantitatively describes the overall deceleration degree of the affected side relative to the healthy side by calculating the gait cycle proportionality coefficient K=T2 / T1: if K=1, it indicates that the walking speed of the affected side is the same as that of the healthy side; if K>1, it indicates that the affected side walks slower than the healthy side, and the larger the K value, the slower the walking speed. Based on the principle of gait time-domain scaling—that is, the duration of each gait phase on the affected side should be scaled proportionally with the overall gait cycle—the system multiplies the muscle contraction time difference Δt1 recorded on the healthy side by the gait cycle proportionality coefficient K to obtain the stimulus delay Δt2=Δt1*K corresponding to the affected side. The physical meaning of this formula is that if the affected side walks twice as slowly as the healthy side (K=2), then the time interval between the activation of the quadriceps muscle on the affected side and the need for the tibialis anterior muscle on the affected side to exert force should also be doubled to ensure that electrical stimulation is triggered at the correct gait phase. Conversely, if the affected side recovers well and its gait speed is close to that of the healthy side (K close to 1), the stimulation delay is essentially equivalent to the physiological time difference of the healthy side. This mechanism solves the problem of premature or late stimulation caused by the use of fixed stimulation delay in existing technologies, achieving dynamic adaptation of stimulation timing according to the patient's real-time gait speed. This ensures that regardless of whether the patient walks fast or slow, electrical stimulation can always accurately fall within the time window required for each core synergistic phase.

[0029] Step S50: Calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0. The core of the above steps lies in achieving quantitative dynamic adaptation of stimulus intensity through muscle force frequency domain difference compensation. Specifically, the amplitude of the electromyographic signal directly reflects the activation intensity of muscle contraction, while the electromyographic amplitude ratio R (quadriceps amplitude / tibialis anterior amplitude) further reveals the relative force relationship between the two muscles in synergistic work. R1, recorded during the healthy side learning phase, represents the healthy force ratio that the healthy quadriceps and tibialis anterior muscles should have under normal conditions; while R2, recorded during the real-time acquisition on the affected side, reflects the actual force ratio of the affected quadriceps and tibialis anterior muscles. Since foot drop patients mainly exhibit impaired dorsiflexion function of the tibialis anterior muscle, the electromyographic amplitude of the affected tibialis anterior muscle is often significantly lower than that of the healthy side, resulting in an R2 value greater than the R1 value. This invention quantitatively characterizes the degree of functional loss of the tibialis anterior muscle on the affected side compared to the healthy side by calculating the muscle strength deficit difference ΔR = R1 - R2. Understandably, a larger ΔR value indicates a more severe tibialis anterior muscle weakness, requiring greater electrical stimulation for compensation. As the affected side gradually recovers and the tibialis anterior muscle's strength improves, R2 gradually approaches R1, and ΔR gradually decreases, even approaching zero. At this point, the required stimulation intensity also decreases. Based on this, the system uses the clinically calibrated initial effective stimulation threshold I0 (i.e., the minimum stimulation intensity that allows the patient's ankle dorsiflexion to reach or exceed 90°) as a benchmark reference value, combined with real-time ΔR, to dynamically calculate the actual stimulation intensity currently required. The technical significance of this dynamic adjustment mechanism lies in two aspects: First, it enables a leap from qualitative estimation to quantitative compensation, allowing the output intensity of electrical stimulation to precisely match the patient's current degree of muscle weakness, avoiding insufficient stimulation (inability to complete effective dorsiflexion) or excessive stimulation (causing muscle fatigue or discomfort); second, as the patient's rehabilitation progresses, the voluntary exertion ability of the tibialis anterior muscle on the affected side gradually recovers, the ΔR value decreases accordingly, and the intensity of the system's output stimulation is also gradually reduced, achieving a natural transition from electrical stimulation-led correction to a patient-centered voluntary movement with electrical stimulation as an auxiliary measure. This fully conforms to the physiological laws of neurorehabilitation and solves the core defect of existing technologies where the stimulation intensity is fixed and cannot be dynamically adjusted with the progress of rehabilitation.

[0030] Step S60: Based on the stimulation delay and the stimulation intensity, electrically stimulate the tibialis anterior muscle on the affected side during each second core synergistic phase.

[0031] The core of the above steps lies in precisely applying the two parameters calculated in the preceding steps to the tibialis anterior muscle on the affected side, thereby restoring multiple physiological synergies within the gait cycle. Specifically, after calculating the stimulation delay Δt2 in step S40 and dynamically adjusting the stimulation intensity in step S50, the system has obtained two core control parameters for the patient's current gait state. The task of step S60 is to monitor the gait phase progression in real time during the operation of the gait cycle on the affected side. When the system identifies the arrival of each pre-selected second core synergy phase, it outputs a dynamically adjusted current intensity according to the corresponding Δt2 (based on the activation time of the quadriceps femoris on the affected side, delayed by Δt2), precisely stimulating the tibialis anterior muscle on the affected side to induce functional contraction. It is particularly important to emphasize that since at least two core synergy phases are selected in steps S10 and S30, the execution of step S60 is not a single stimulation, but rather the triggering of stimulation at multiple different time points within the same gait cycle, with each stimulation using its own independent Δt2 and dynamic stimulation intensity parameters.

[0032] The technical solution of this invention, on the one hand, obtains the gait cycle duration T1 of the healthy side, the muscle contraction time difference Δt1, and the real-time gait cycle duration T2 of the affected side, calculates the gait cycle proportionality coefficient K=T2 / T1, and dynamically calculates the stimulation delay of the affected side based on Δt2=Δt1×K. Simultaneously, by recording the electromyographic amplitude ratio R1 of the healthy side and the electromyographic amplitude ratio R2 of the affected side, it calculates the muscle weakness difference ΔR=R1-R2 and dynamically adjusts the stimulation intensity of the tibialis anterior muscle on the affected side according to ΔR and the initial effective stimulation threshold I0. This achieves dual dynamic adaptive stimulation delay and intensity, solving the problems of manually preset fixed values ​​for stimulation parameters in existing technologies, and lack of... This approach addresses the differences in basic gait among patients and the ratio of gait cycles between the healthy and affected sides. On the other hand, it selects at least two corresponding core synergistic phases (the first and second core synergistic phases) within the gait cycles of both the healthy and affected sides, and electrically stimulates the tibialis anterior muscle on the affected side during each core synergistic phase. This overcomes the limitations of existing techniques that rely on single stimulation within a single gait cycle, restoring the multiple core synergistic relationships between the quadriceps and tibialis anterior muscles at different gait stages during normal walking. This results in a more natural and fluid gait after correction, avoiding stiffness. The combination of these two approaches achieves gait correction that is both individualized and physiologically sound.

[0033] Understandably, the core principle of this electrical stimulation method lies in using the physiological electromyographic signals of the patient's healthy side as a golden benchmark. By establishing a gait time-domain mapping relationship and a muscle force frequency-domain mapping relationship between the healthy and affected sides, it achieves dual dynamic adaptive control of the timing and intensity of stimulation on the affected side, and restores multiple muscle physiological coordinations within the gait cycle. Specifically, this principle includes three progressively layered logical levels; The first level involves establishing a baseline and constructing an individualized template. During normal walking, the quadriceps femoris and tibialis anterior muscles exhibit a fixed physiological coordination pattern, including specific muscle contraction timing, muscle contraction time difference, and electromyographic amplitude ratio. This invention collects electromyographic signals from the two muscles on the patient's unaffected side, calculates the gait cycle duration T1, electromyographic amplitude ratio R1, and muscle contraction time difference Δt1, thereby constructing a unique and dynamic physiological gait template for the patient. The unaffected side is chosen as the baseline because, for hemiplegic patients, the motor control mechanism on the unaffected side is complete, best reflecting the patient's own normal gait characteristics. Using this as a reference allows for truly individualized correction, rather than relying on general thresholds or external sensor estimations.

[0034] The second layer is a two-parameter dynamic adaptive mathematical mapping mechanism, which is also the core algorithm principle of this invention. On the one hand, regarding stimulation delay, this method is based on the scaling principle of the gait time domain: due to impaired neural control on the affected side, the gait cycle duration T2 often differs proportionally from that on the healthy side. By calculating the gait cycle proportionality coefficient K=T2 / T1, the muscle contraction time difference Δt1 recorded on the healthy side (representing the time interval between the initiation of two muscles) can be scaled proportionally according to the K value to obtain the stimulation delay Δt2=Δt1*K on the affected side. Its physical meaning is: if the walking speed on the affected side is half that on the healthy side (K=2), then the stimulation delay between the quadriceps femoris and tibialis anterior muscles on the affected side should also be doubled to ensure that the electrical stimulation falls on the correct gait phase. On the other hand, regarding stimulation intensity, this method is based on the principle of difference compensation in the muscle force frequency domain: the amplitude of the electromyographic signal directly reflects the activation intensity of the muscle. By calculating the amplitude ratio R1 of the electromyographic signal on the healthy side and R2 on the affected side, the muscle strength deficit difference ΔR = R1 - R2 quantitatively reflects the degree of functional loss on the affected side compared to the healthy side. The larger ΔR is, the more insufficient the force exerted on the affected side, and the greater the intensity of electrical stimulation compensation required; conversely, as rehabilitation progresses, ΔR gradually decreases, and the stimulation intensity is adjusted accordingly. This mechanism achieves a gradual transition from electrical stimulation-dominated to patient-dominated voluntary force exertion.

[0035] The third level is the multi-time-point physiological synergistic restoration mechanism. In a normal gait cycle, the quadriceps and tibialis anterior muscles do not only coordinate once. This invention selects at least two first core synergistic phases within the healthy side's gait cycle, records the physiological parameters of each coordination, and triggers stimulation in the corresponding second core synergistic phase on the affected side. This restores the multiple muscle synergistic relationships within the gait cycle in the time dimension, transforming the corrected gait from a single, stiff flexion movement into a continuous and natural multi-coordinated movement.

[0036] In summary, the essence of this electrical stimulation method is a biosignal feedback control system driven by physiological signals from the healthy side, with time-domain scaling and frequency-domain compensation as the core algorithms, and multi-time-point collaboration as the execution framework. By transplanting the patient's own normal movement pattern to the affected side, it achieves precise, physiological, and adaptive gait correction for foot drop.

[0037] As a preferred embodiment of the above, the electrical stimulation method is configured with three first core coordination phases, which correspond to the early support phase, the early swing phase, and the late swing phase, respectively. The early support phase corresponds to the heel-to-full-foot weight-bearing phase, the early swing phase corresponds to the toe-to-step phase, and the late swing phase corresponds to the heel-to-ground preparation phase.

[0038] With this setup, during a complete gait cycle of normal walking, the quadriceps and tibialis anterior muscles do not work together in a single phase, but rather in three specific phases with different biomechanical functions, each involving core synergistic events. The first is the early stance phase, corresponding to the period from heel touches the ground to full weight-bearing (approximately 0%-15% of the gait cycle). During this phase, the quadriceps contract eccentrically to cushion the impact of body weight on the knee joint, while the tibialis anterior contracts eccentrically to control the slow descent of the ankle. Together, they coordinate to cushion the landing. The second is the early swing phase, corresponding to the first half of the step from toe lift off the ground (approximately 60%-75% of the gait cycle). During this phase, the quadriceps contract concentrically to flex the knee joint to complete the leg lift, while the tibialis anterior contracts concentrically to actively dorsiflex the ankle (pointing the toes) to prevent dragging the toes. Together, they coordinate to lift off the ground. The third phase is the end of the swing phase, corresponding to the latter half of the stepping motion until the heel prepares to strike the ground (approximately 85%-100% of the gait cycle time window). During this phase, the quadriceps contract eccentrically to control the slow extension of the knee joint in preparation for landing, while the tibialis anterior contracts pre-contract to adjust the ankle posture for a smooth landing. Both work together to complete the pre-landing preparation. The technical significance lies in the fact that these three phases precisely cover the complete closed loop of the gait cycle, from landing cushioning to take-off and landing preparation. Each phase has a clear biomechanical functional goal; any deficiency in tibialis anterior muscle function at any stage will lead to gait abnormalities—insufficient tibialis anterior control in the early stance phase will result in foot slapping (slapping sound); insufficient tibialis anterior force in the early swing phase will result in foot drop and dragging; and insufficient tibialis anterior pre-contraction at the end of the swing phase will result in unstable landing posture. Therefore, by applying electrical stimulation in these three phases, various abnormal manifestations in foot drop patients throughout the entire gait cycle can be systematically addressed, making the corrected gait closer to physiological states in every stage of cushioning, stepping, and landing.

[0039] It should be noted that, after understanding the technical solution of this application, those skilled in the art can select more than three first core synergistic stages within the healthy side gait cycle without creative effort. As the number of first core synergistic stages selected increases, the refinement and physiological restoration of the gait correction on the affected side will be further improved. However, such an increase in the number does not constitute a substantial innovation of this invention and still falls within the scope of simple variations or equivalent substitutions of the technical solution of this invention.

[0040] As a preferred embodiment of the above, step S20 includes the following steps: Step S21: Gradually output pulse current to the tibialis anterior muscle on the affected side according to the current intensity from low to high, while requiring the patient to voluntarily complete ankle dorsiflexion until the patient's ankle joint dorsiflexion angle reaches or exceeds 90°. Step S22: Record the current intensity of the current output pulse current as the initial effective stimulation threshold I0.

[0041] This setup, due to significant individual differences in the degree of muscle atrophy, nerve damage, and tissue impedance among patients, means that a single preset, fixed stimulation intensity cannot be applied to all patients—too low an intensity will not induce effective movement, while too high an intensity may cause muscle fatigue or discomfort. This invention designs a standardized clinical calibration procedure through step S21: after attaching electrodes to the tibialis anterior muscle on the affected side of the patient, clinical personnel or the system automatically control the pulsed current, starting from a very low, safe initial value and gradually increasing the output intensity in preset increments; at each intensity level, the patient is required to actively exert force to complete ankle dorsiflexion (pointing the toes), rather than passively relying on electrical stimulation. This combined mode of electrical stimulation and patient-initiated effort has significant physiological implications—it simulates the real-world scenario of electrical stimulation assisting patients in completing movements during rehabilitation training. The calibrated threshold I0 reflects the minimum stimulation intensity at which the combined force of electrical stimulation and the patient's residual muscle strength can achieve the functional goal, rather than completely replacing the intensity of the patient's own effort. In step S22, when clinicians confirm through visual inspection or angle sensors that the patient's ankle dorsiflexion angle reaches or exceeds 90° for the first time (i.e., the angle between the dorsum of the foot and the front of the lower leg is less than 90°, at which point the toes are fully raised, meeting the functional requirement of keeping the toes on the ground during walking), the current output pulse current intensity is immediately recorded as the initial effective stimulation threshold I0. The technical significance of this calibration method is reflected in three aspects: First, clear quantitative standards; using a 90° dorsiflexion angle as the gold standard avoids the subjectivity of traditional methods that rely on feeling or experience to set the intensity; second, individualized precision; each patient's I0 is obtained based on their own anatomical structure and residual muscle strength, ensuring that the stimulation intensity is precisely within an effective and comfortable range; third, rehabilitation adaptation; because the calibration process requires the patient to actively exert force simultaneously, the recorded I0 actually includes the patient's current active participation ability, providing a benchmark reference value directly related to the patient's own state for subsequent dynamic intensity adjustments based on ΔR.

[0042] As a preferred embodiment of the above, step S50 includes the following steps: Step S51: During the affected side training phase, continuously acquire the electromyographic signals of the affected quadriceps femoris and tibialis anterior muscles on the affected side; record the actual electromyographic amplitude ratio Ri of the affected quadriceps femoris and tibialis anterior muscles in each second core synergy phase based on the electromyographic signals of the affected side. Step S52: Calculate the actual muscle strength deficit difference ΔRi, where ΔRi = R1 - Ri; Step S53: Obtain the actual stimulus intensity Ii, where Ii = I0 * (ΔRi / ΔR).

[0043] With this setup, after initial calibration and entering the affected-side training phase, the patient's muscle strength is not static. As rehabilitation progresses, the voluntary exertion ability of the affected tibialis anterior muscle will gradually recover. If the initial stimulation intensity is continued at this point, it will lead to overstimulation, which may not only cause muscle fatigue but also hinder the patient's transition to voluntary movement. For these reasons, step S51 continuously collects electromyographic signals from the affected quadriceps and tibialis anterior muscles during training, recording the actual measured electromyographic amplitude ratio Ri (i.e., the real-time ratio of the amplitude of the affected quadriceps to that of the affected tibialis anterior muscle at the current moment) in each second core synergy phase, thereby achieving dynamic monitoring of the patient's muscle strength. Step S52 further calculates the actual muscle strength deficit difference ΔRi = R1 - Ri, where R1 is the ratio of electromyographic amplitude on the healthy side, and Ri is the actual electromyographic amplitude on the affected side: when the strength of the tibialis anterior muscle on the affected side improves, its electromyographic amplitude increases, leading to a decrease in Ri (approaching R1), thus ΔRi decreases accordingly; conversely, if the patient is fatigued or in poor condition, resulting in a decrease in the strength of the tibialis anterior muscle, Ri increases, and ΔRi increases accordingly. Step S53 gives the dynamic calculation formula for stimulation intensity: Ii = I0 * (ΔRi / ΔR), where I0 is the initial effective stimulation threshold, ΔR is the initial muscle strength deficit difference at the first calibration, and ΔRi is the actual muscle strength deficit difference at the current moment. The physical meaning of this formula is as follows: using the initial state as a baseline, the ratio of the current degree of muscle weakness to the initial degree of weakness is used as a scaling factor to dynamically adjust the output stimulation intensity; when the affected side recovers well and ΔRi shrinks to half of the initial value, the stimulation intensity is also automatically halved; when the patient fully recovers and ΔRi approaches zero, the stimulation intensity also approaches zero, achieving automatic withdrawal of electrical stimulation. This closed-loop regulation mechanism formed by these three steps achieves a qualitative change from fixed compensation to on-demand compensation, ensuring that the electrical stimulation output is always precisely matched with the patient's current real-time muscle strength state. This avoids both correction failure caused by insufficient stimulation and muscle fatigue caused by excessive stimulation, achieving dynamic adjustment of stimulation intensity.

[0044] As a preferred embodiment of the above, after step S60, the following steps are further included: Step S70: After continuously executing steps S30 to S60 for the preset training cycle, step S10 is executed again to update the gait cycle duration T1 of the healthy side, the electromyographic amplitude ratio R1 of the healthy quadriceps and the healthy tibialis anterior, and the muscle contraction time difference Δt1, and step S20 is executed again to update the initial effective stimulation threshold I0; in this embodiment, the preset training cycle is configured to be 1 to 2 weeks; Step S80: Overwrite the original parameters with the updated parameters, and return to execute steps S30 to S60.

[0045] With this setup, the patient's rehabilitation is a dynamic process. With continuous training, the gait ability, muscle strength, and neural control efficiency of both the healthy and affected sides will improve to varying degrees. For example, the affected side will experience faster walking speed and increased electromyographic amplitude due to functional recovery. If the baseline parameters (T1, R1, Δt1) and the initial effective stimulation threshold I0 of the healthy side collected in the initial stage are always used, the baseline template will become disconnected from the patient's current actual state, leading to systematic deviations in subsequent delay calculations and intensity compensation. Step S70 automatically triggers a complete reassessment process at the end of each preset training cycle (such as the clinically recommended 1 to 2 weeks): First, step S10 is re-executed to collect the electromyographic signal of the patient's current healthy side again, updating the gait cycle duration T1, electromyographic amplitude ratio R1, and muscle contraction time difference Δt1 of the healthy side, ensuring that the baseline template always reflects the true physiological state of the patient's current normal side; simultaneously, step S20 is re-executed to stimulate the ankle joint dorsiflexion angle again through gradient increment stimulation, calibrating the minimum stimulation intensity I0 that the patient can currently achieve 90° functional dorsiflexion. This value usually gradually decreases as the active force exertion ability of the affected side improves. Step S80 then uses the updated parameters (new T1, new R1, new Δt1, new I0) to overwrite the original parameters in the storage module and automatically returns to execute steps S30 to S60, so that the subsequent training phase of the affected side is based on the latest baseline data and thresholds for delay calculation and intensity compensation. The technical significance of this periodic reassessment mechanism lies in two aspects: First, it solves the benchmark drift problem during rehabilitation, ensuring that the algorithm always uses the patient's current real physiological state as a reference, avoiding a decrease in control accuracy due to outdated benchmarks. Second, with the natural iterative updates of parameters—the T2 / T1 ratio approaches 1 (improved gait symmetry), ΔR gradually decreases (repair of muscle weakness), and I0 gradually decreases (improved voluntary exertion ability)—the stimulation delay and intensity output by the system will automatically and gradually decrease, achieving a seamless transition from electrical stimulation-led rehabilitation to patient-led voluntary movement and electrical stimulation-assisted monitoring, which fully conforms to the dynamic evolution law of neurorehabilitation.

[0046] To address the aforementioned technical problems, this invention proposes an electrical stimulation device for correcting gait in hemiplegic foot drop, used to perform the electrical stimulation method described in any of the above embodiments; Specifically, refer to Figure 2 The electrical stimulation device includes: A dual-channel electrode unit is used to acquire electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; to acquire electromyographic signals of the affected quadriceps femoris and tibialis anterior muscle on the affected side; and to perform electrical stimulation on the affected tibialis anterior muscle in each second core synergistic phase according to the stimulation delay and the stimulation intensity. The main control unit is electrically connected to the dual-channel electrode unit; the main control unit includes: The gait cycle calculation module is used to calculate the duration T1 of the gait cycle on the healthy side based on the electromyographic signal on the healthy side; and to calculate the duration T2 of the gait cycle on the affected side based on the electromyographic signal on the affected side. The collaborative timing identification module is used to record the electromyographic amplitude ratio R1 of the healthy quadriceps femoris and the healthy tibialis anterior muscle, the muscle contraction sequence, and the muscle contraction time difference Δt1 in each of the first core collaborative phases; and to record the electromyographic amplitude ratio R2 of the affected quadriceps femoris and the affected tibialis anterior muscle in each of the second core collaborative phases. An adaptive calculation module is used to calculate the gait cycle proportional coefficient K, where K = T2 / T1; and based on the gait cycle proportional coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K; and calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0.

[0047] With this configuration, the electrostimulation device provided by the present invention achieves the organic unity of "integrated acquisition and stimulation" and "separate management of healthy and affected sides" through the collaborative design of the dual-channel electrode unit and the main control unit. Specifically, each group of electrodes in the dual-channel electrode unit has both electromyographic signal acquisition and electrical stimulation output functions, eliminating the need for separate electrode components for acquisition and stimulation, simplifying the device structure and reducing the complexity of clinical operation. At the same time, the dual-channel electrode unit can perform electromyographic signal acquisition only on the healthy side (pure acquisition mode) and simultaneously perform electromyographic signal acquisition and electrical stimulation output on the affected side (acquisition + stimulation mode). This separate management mode ensures the realization of the core technical concept based on the healthy side from a physical perspective. The gait cycle calculation module integrated within the main control unit is responsible for accurately extracting the gait cycle durations T1 and T2 from the electromyographic signals of the healthy and affected sides. The coordination timing recognition module is responsible for recording the core coordination parameters of the healthy side (EMG amplitude ratio R1, contraction sequence, and contraction time difference Δt1) and the corresponding real-time parameters of the affected side (EMG amplitude ratio R2). The adaptive calculation module integrates two core algorithms—stimulation delay adaptive logic based on K=T2 / T1 and Δt2=Δt1*K, and stimulation intensity adaptive logic based on ΔR=R1-R2 and I0. This enables the entire device to achieve dual dynamic adaptation of stimulation timing and stimulation intensity with lightweight algorithms without relying on complex AI models or high-end hardware, and the calculation cycle can be controlled within 10ms.

[0048] As a preferred embodiment of the above, the dual-channel electrode unit includes at least two sets of electrodes, each set of electrodes having electromyographic signal acquisition and electrical stimulation output functions; the electrodes are fixed to the lateral quadriceps femoris, the healthy tibialis anterior muscle, the affected quadriceps femoris, and the affected tibialis anterior muscle by means of flexible straps or adhesive patches.

[0049] With this setup, each electrode group simultaneously possesses electromyography (EMG) signal acquisition and electrical stimulation output functions, achieving integrated acquisition and stimulation. This means that there is no need to configure separate electrode components for acquisition and stimulation, greatly simplifying the device structure, reducing the number of electrodes attached to the patient's skin, and lowering the complexity of clinical operation and the economic burden on patients. At the same time, the electrodes are fixed to the muscles using flexible straps or adhesive patches. The compliance of the flexible material ensures stable contact between the electrodes and the skin, effectively suppressing motion artifacts from interfering with EMG signals, thereby obtaining high-quality microvolt-level EMG signals. Furthermore, the adjustable straps or ready-to-use patch design can adapt to patients of different body types and muscle circumferences, ensuring that the electrodes can be accurately positioned at the center of the quadriceps femoris and tibialis anterior muscle belly.

[0050] As a preferred embodiment of the above embodiments, the electrical stimulation device includes an electromyography signal processing module for filtering, amplifying, and analyzing the electromyography signals from the healthy side and the affected side. With this setup, the human electromyography (EMG) signal, essentially a weak bioelectrical signal at the microvolt (μV) level, is highly susceptible to contamination from various noises, including skin impedance, respiratory movements, environmental electromagnetic interference, and crosstalk from adjacent muscles. Without effective processing, the true physiological information in the original EMG signal will be completely overwhelmed by noise, leading to errors in gait cycle recognition and distortion in the calculation of the EMG amplitude ratio (R value). Consequently, subsequent adaptive adjustments to stimulation delay and intensity lack a reliable data foundation. This invention addresses this by setting up a dedicated EMG signal processing module that sequentially performs three core processing steps on the acquired EMG signals from both the healthy and affected sides: filtering, amplification, and analysis. The filtering stage effectively removes power frequency interference, motion artifacts, and residual noise from electrical stimulation pulses, preserving pure EMG physiological signals. The amplification stage boosts the microvolt-level signal to an analyzable voltage range, ensuring the accuracy of subsequent analog-to-digital conversion. The analysis stage accurately extracts key characteristic parameters such as EMG amplitude, muscle activation sequence, and gait cycle boundaries from the processed signal. The existence of this module enables the entire device to acquire high-quality, high-signal-to-noise-ratio electromyographic signals even in a strong interference environment with frequent electrical stimulation pulse output, providing real and reliable data input for the gait cycle calculation module, the coordination timing recognition module, and the adaptive calculation module.

[0051] As a preferred embodiment of the above, the electrical stimulation device includes a time-division multiplexing control module for controlling the shutdown of the electromyographic signal acquisition channel during pulse current output and immediately restoring the electromyographic signal acquisition function after the electrical stimulation is completed.

[0052] This setup presents a long-standing technical contradiction in functional electrical stimulation devices: the electrical stimulation output terminal delivers milliampere (mA) level pulsed currents, while the electromyography (EMG) acquisition terminal needs to capture microvolt (μV) level physiological signals, resulting in an intensity difference of thousands of times. If EMG acquisition is performed simultaneously with electrical stimulation output, the powerful stimulation pulse will directly overwhelm the weak EMG signal through tissue conduction and electrode coupling, leading to complete data distortion, manifested as signal saturation, baseline drift, or artifact interference. This makes subsequent processing such as gait cycle recognition and EMG amplitude ratio calculation unreliable. To address these issues, this invention employs a time-division multiplexing control module to completely isolate the acquisition and stimulation processes in time: within the brief time window of pulsed current output (typically microseconds to milliseconds), the EMG signal acquisition channel is actively shut down, placing the acquisition circuit in a high-impedance state or disconnected state, physically preventing strong stimulation signals from entering the acquisition front end; and immediately after the stimulation pulse ends, the EMG acquisition function is restored to capture interference-free, pure EMG signals. Since electrical stimulation pulses are typically output in the form of intermittent short pulse sequences (e.g., pulse width 100-300 microseconds, pulse interval tens of milliseconds), the time window for closing the acquisition only accounts for a very small proportion of the total time (usually less than 1%), which does not cause the loss of continuity of electromyographic signals and does not affect the real-time tracking of gait cycles and the extraction of key parameters. The design of this module enables the device to simultaneously achieve acquisition and stimulation functions on the same electrode or adjacent electrodes, without the need to configure separate, spatially separated electrode systems for both. This simplifies the device structure and reduces operational complexity, fundamentally solving the long-standing technical problem of mutual interference between acquisition and stimulation signals in the field of functional electrical stimulation, and providing a clean and reliable data foundation for closed-loop adaptive control.

[0053] As a preferred embodiment of the above, the electrical stimulation device includes a power supply unit, which is electrically connected to the dual-channel electrode unit and the main control unit; the power supply unit has a built-in overvoltage and overcurrent protection circuit, supports a low battery reminder function, and has a battery life of ≥8 hours.

[0054] This design, with its built-in overvoltage and overcurrent protection circuits, ensures that the power supply unit can automatically cut off or limit the output when abnormal voltage or current increases due to poor electrode contact, short circuits, or sudden changes in the patient's skin impedance. This effectively prevents device damage and patient burns, significantly improving the safety of clinical use. Simultaneously, the low battery reminder function allows clinicians or patients to be aware of the status and recharge before the battery runs out, avoiding the risk of falls caused by sudden interruptions in gait correction due to power outages during training. The design provides a battery life of ≥8 hours, covering a full treatment day in a hospital rehabilitation department (typically 6-8 hours) and also meeting the needs of multiple training sessions in home rehabilitation settings, eliminating the need for frequent charging and ensuring continuous device availability and treatment adherence.

[0055] It should be noted that the other contents of the electrical stimulation device and electrical stimulation method for gait correction of hemiplegic foot drop disclosed in this invention are prior art and will not be described in detail here.

[0056] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. Any application of the present invention directly or indirectly in other related technical fields is included within the patent protection scope of the present invention.

Claims

1. An electrical stimulation method for gait correction in hemiplegic foot drop, characterized in that, The electrical stimulation method includes the following steps: Step S10: Obtain the electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; calculate the duration T1 of the healthy side gait cycle based on the electromyographic signals of the healthy side, and select at least two first core synergy phases within the healthy side gait cycle, and record the electromyographic amplitude ratio R1, muscle contraction sequence, and muscle contraction time difference Δt1 of the healthy quadriceps femoris and tibialis anterior muscle in each first core synergy phase; Step S20: Obtain the initial effective stimulation threshold I0 on the affected side; Step S30: Obtain electromyographic signals of the quadriceps femoris and tibialis anterior muscles on the affected side. The duration T2 of the gait cycle on the affected side is calculated based on the electromyographic signal on the affected side, and at least two second core synergy phases are selected within the gait cycle on the affected side, and the ratio R2 of the electromyographic amplitude of the quadriceps femoris and the tibialis anterior muscle on the affected side is recorded in each second core synergy phase; wherein the second core synergy phase corresponds to the first core synergy phase; Step S40: Calculate the gait cycle proportionality coefficient K, where K = T2 / T1; and based on the gait cycle proportionality coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and the tibialis anterior muscle on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K. Step S50: Calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0. Step S60: Based on the stimulation delay and the stimulation intensity, electrically stimulate the tibialis anterior muscle on the affected side during each second core synergistic phase.

2. The electrical stimulation method as described in claim 1, characterized in that: The electrical stimulation method is configured with three first core coordination phases, which correspond to the early support phase, the early swing phase, and the late swing phase, respectively. The early support phase corresponds to the heel-to-full foot weight-bearing phase, the early swing phase corresponds to the toe-to-step phase, and the late swing phase corresponds to the heel-to-ground preparation phase.

3. The electrical stimulation method as described in claim 1, characterized in that: Step S20 includes the following steps: Step S21: Gradually output pulse current to the tibialis anterior muscle on the affected side according to the current intensity from low to high, while requiring the patient to voluntarily complete ankle dorsiflexion until the patient's ankle joint dorsiflexion angle reaches or exceeds 90°. Step S22: Record the current intensity of the current output pulse current as the initial effective stimulation threshold I0.

4. The electrical stimulation method as described in claim 1, characterized in that: Step S50 includes the following steps: Step S51: During the affected side training phase, continuously acquire the electromyographic signals of the affected quadriceps femoris and tibialis anterior muscles on the affected side; record the actual electromyographic amplitude ratio Ri of the affected quadriceps femoris and tibialis anterior muscles in each second core synergy phase based on the electromyographic signals of the affected side. Step S52: Calculate the actual muscle strength deficit difference ΔRi, where ΔRi = R1 - Ri; Step S53: Obtain the actual stimulus intensity Ii, where Ii = I0 * (ΔRi / ΔR).

5. The electrical stimulation method according to any one of claims 1 to 4, characterized in that: Following step S60, the following steps are also included: Step S70: After continuously executing the preset training cycles from step S30 to step S60, re-execute step S10 to update the gait cycle duration T1 of the healthy side, the electromyographic amplitude ratio R1 of the healthy quadriceps and the healthy tibialis anterior, and the muscle contraction time difference Δt1, and re-execute step S20 to update the initial effective stimulation threshold I0. Step S80: Overwrite the original parameters with the updated parameters, and return to execute steps S30 to S60.

6. The electrical stimulation method as described in claim 5, characterized in that: The preset training period is configured to be 1 to 2 weeks.

7. An electrical stimulation device for correcting gait in hemiplegic foot drop, used to perform the electrical stimulation method as described in any one of claims 1 to 6; characterized in that, The electrical stimulation device includes: A dual-channel electrode unit is used to acquire electromyographic signals of the healthy quadriceps femoris and tibialis anterior muscle on the healthy side; to acquire electromyographic signals of the affected quadriceps femoris and tibialis anterior muscle on the affected side; and to perform electrical stimulation on the affected tibialis anterior muscle in each second core synergistic phase according to the stimulation delay and the stimulation intensity. The main control unit is electrically connected to the dual-channel electrode unit; the main control unit includes: The gait cycle calculation module is used to calculate the duration T1 of the gait cycle on the healthy side based on the electromyographic signal on the healthy side; and to calculate the duration T2 of the gait cycle on the affected side based on the electromyographic signal on the affected side. The collaborative timing identification module is used to record the electromyographic amplitude ratio R1 of the healthy quadriceps femoris and the healthy tibialis anterior muscle, the muscle contraction sequence, and the muscle contraction time difference Δt1 in each of the first core collaborative phases; and to record the electromyographic amplitude ratio R2 of the affected quadriceps femoris and the affected tibialis anterior muscle in each of the second core collaborative phases. An adaptive calculation module is used to calculate the gait cycle proportional coefficient K, where K = T2 / T1; and based on the gait cycle proportional coefficient K, obtain the stimulation delay Δt2 between the quadriceps femoris and tibialis anterior muscles on the affected side in each second core synergistic phase on the affected side, where Δt2 = Δt1 * K; and calculate the muscle weakness difference ΔR, where ΔR = R1 - R2; and dynamically adjust the stimulation intensity of the tibialis anterior muscle on the affected side based on the muscle weakness difference ΔR and the initial effective stimulation threshold I0.

8. The electrical stimulation device as claimed in claim 7, characterized in that: The dual-channel electrode unit includes at least two sets of electrodes, each set of electrodes having the functions of electromyographic signal acquisition and electrical stimulation output; the electrodes are fixed to the lateral quadriceps femoris, the contralateral tibialis anterior, the affected quadriceps femoris, and the affected tibialis anterior by flexible bandages or adhesive patches.

9. The electrical stimulation device as claimed in claim 7, characterized in that: The electrical stimulation device also includes: The electromyography (EMG) signal processing module is used to filter, amplify, and analyze the EMG signals from both the healthy and affected sides. And / or, a time-division multiplexing control module is used to control the shutdown of the electromyography signal acquisition channel during pulse current output and to immediately restore the electromyography signal acquisition function after the electrical stimulation is completed.

10. The electrical stimulation device according to any one of claims 7 to 9, characterized in that: The electrical stimulation device includes a power supply unit, which is electrically connected to the dual-channel electrode unit and the main control unit; the power supply unit has a built-in overvoltage and overcurrent protection circuit, supports a low battery reminder function, and has a battery life of ≥8 hours.

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