Lower extremity intelligent pressure regulating elastic socks integrated with ultrasonic monitoring and working method thereof

Abstract

The present application relates to the technical field of medical thrombus prevention equipment, in particular to a lower limb intelligent pressure regulating elastic sock integrated with ultrasonic monitoring and a working method thereof, which comprises a medical elastic sock body and further comprises: a plurality of patch ultrasonic transducer units, which are correspondingly arranged in a plurality of internal fixing cavities of the medical elastic sock body and are sequentially arranged from top to bottom along the anatomical sites of the main trunk veins of the lower limbs of human bodies, and the sound window surfaces of the patch ultrasonic transducer units are all attached to the skin through coupling gel, and are used for non-invasive quantitative collection of ultrasonic echo signals of lower limb venous hemodynamics. The present application realizes efficient and safe prevention through innovative closed-loop linkage, differentiated driving and precise controllable pressurization. Taking the ultrasonic monitoring quantitative blood flow index as the core trigger signal, the present application breaks through the technical barriers of traditional ultrasonic diagnosis and passive prevention of elastic socks, constructs an integrated closed loop of "monitoring-early warning-intervention", dynamically adapts the risk level, and significantly improves the timeliness and accuracy of prevention.

Description

Technical Field

[0001] This invention relates to the field of medical thrombosis prevention equipment technology, specifically to a lower limb intelligent pressure-adjustable elastic stocking with integrated ultrasound monitoring and its working method. Background Technology

[0002] Deep vein thrombosis (DVT) of the lower extremities is a common vascular disease in clinical practice. People who sit for long periods, lie down for long periods, or are bedridden after surgery are at high risk. Once a thrombus forms, it can easily lead to serious complications such as pulmonary embolism, threatening the patient's life and health. Because early symptoms of DVT are often subtle, relying solely on clinical symptom monitoring can easily result in missed diagnoses. Since a thrombus can easily cause serious complications such as pulmonary embolism, it is crucial to achieve early warning of thrombosis and combine it with physical intervention to reduce disability and mortality rates.

[0003] Current clinical prevention and treatment of deep vein thrombosis (DVT) primarily relies on two core approaches: First, physical prevention using medical graded compression stockings. These stockings utilize decreasing pressure from the ankle to the proximal thigh to promote venous return in the lower limbs, alleviate blood stasis, and block the triggers for thrombosis. However, traditional medical graded compression stockings have a fixed factory elasticity, allowing only passive compression and lacking dynamic adjustment based on the patient's real-time blood flow status, easily leading to insufficient or excessive compression. Second, ultrasound equipment is used for blood flow monitoring and lesion diagnosis to detect early signs of thrombosis. However, ultrasound monitoring can only diagnose and warn of thrombosis, lacking a linkage mechanism with the compression prevention of compression stockings, resulting in a "separation of monitoring and intervention," which fails to achieve precise and timely prevention of thrombosis.

[0004] Furthermore, a search revealed numerous devices for preventing lower extremity deep vein thrombosis. While each device has its advantages, significant limitations remain: most devices can only perform single monitoring or single pressure application, resulting in a disconnect between monitoring and intervention (e.g., a polyvinyl chloride gel-driven intermittent self-controlled electrically controlled gradient pressure elastic stocking and its preparation method, patent publication number CN108784933B); or the monitoring parameters are all indirectly inferred, lacking direct imaging diagnostic evidence of thrombosis, resulting in insufficient monitoring accuracy and an inability to provide early warning at the diagnostic level before thrombosis obstructs the lumen (e.g., patent publication number CN12110). (Patent 1894A: a medical thrombosis detection elastic stocking and thrombosis detection method; Patent Publication No. CN120420158A: a smart medical compression stocking). In addition, some of the aforementioned devices suffer from problems such as complex structure, large size, poor portability, fixed site for individualized and precise pressure adjustment, high cost, intermittent stimulation, and poor wearing comfort and long-term compliance. Their universality is limited, making them unsuitable for daily wear and home monitoring scenarios. They fail to meet the dual clinical needs of lower extremity venous thrombosis prevention and treatment, namely, "real-time visualization of early occult thrombosis" and "quantifiable feedback of physical intervention effects." Summary of the Invention

[0005] This invention provides an intelligent pressure-adjustable elastic stocking for the lower limbs with integrated ultrasound monitoring and its working method. It establishes a real-time closed-loop control mechanism for the quantitative early warning data of ultrasound monitoring and the elastic gradient adjustment of the stocking, realizing dynamic, targeted, and graded adjustment of the elastic gradient. This achieves the integration of "monitoring and early warning - active intervention - effect feedback", which can provide a certain degree of timeliness and accuracy for DVT prevention.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A smart pressure-adjustable elastic stocking for the lower limbs with integrated ultrasound monitoring includes a medical elastic stocking body, the surface of which is provided with multiple internal fixation chambers and at least one external fixation chamber, and further includes: Multiple patch ultrasound transducer units are respectively installed in multiple internal fixation chambers of the medical elastic stocking and arranged sequentially from top to bottom along the anatomical sites of the main veins of the lower limbs. The acoustic window of each patch ultrasound transducer unit is attached to the skin through coupling gel for non-invasive quantitative acquisition of ultrasound echo signals of lower limb venous hemodynamics. The elastic stocking intelligent gradient adjustment module includes multiple flexible pressure adjustment units that are detachably connected to the outer surface of the medical elastic stocking. The multiple flexible pressure adjustment units are set one-to-one with the monitoring points of the multiple patch ultrasound transducer units. The elastic stocking intelligent gradient adjustment module is used to implement targeted and graded gradient pressure dynamic adjustment for lower extremity venous thrombosis. The signal processing and transmission unit is located in the external fixation chamber of the medical elastic stocking and is used to receive the ultrasonic echo signals collected by each patch ultrasonic transducer unit and the resistance signals transmitted by the elastic stocking intelligent gradient adjustment module. After processing and analysis, it generates and outputs control commands to the elastic stocking intelligent gradient adjustment module. The signal processing and transmission unit includes an algorithm storage module for determining the DVT risk level based on the ultrasonic echo signal and generating a pressure adjustment strategy, and a micro control chip module for executing the control commands and realizing closed-loop feedback calibration. The central monitoring and early warning unit is wirelessly connected to the signal processing and transmission unit to receive ultrasound monitoring data, elasticity adjustment data and DVT risk data, realize data management and retain manual intervention authority.

[0007] Preferably, each of the flexible pressure regulating units includes: The shape memory polymer flexible annular strip is made of thermally responsive polycaprolactone and has a shrinkage rate of 15% to 20% and a glass transition temperature of 45 to 55°C. A miniature heating element is attached to the outer surface of the shape memory polymer flexible annular strip to transfer heat energy to the shape memory polymer flexible annular strip. A miniature temperature sensor is attached to the center of the shape memory polymer flexible annular strip using thermally conductive adhesive to collect temperature data of the shape memory polymer flexible annular strip in real time. A miniature tension strain gauge is embedded inside the shape memory polymer flexible annular strip to collect tension data of the shape memory polymer flexible annular strip in real time. The external fixation ring is made of medical-grade nylon Velcro, with the hook side sewn to the back of one end of the shape memory polymer flexible annular strip and the rough side sewn to the front of the other end of the shape memory polymer flexible annular strip. The micro heating element, micro temperature sensor, and micro tension strain gauge are all electrically connected to the signal processing and transmission unit.

[0008] Preferably, the plurality of flexible pressure adjustment units are respectively formed on the medical elastic stocking body in area A, which is adapted to the middle section of the calf and corresponds to the middle section of the posterior tibial vein, area B, which is adapted to the popliteal fossa and corresponds to the middle section of the popliteal vein, area C, which is adapted to the middle and lower section of the thigh and corresponds to the middle and lower section of the femoral vein, and area D, which is adapted to the upper section of the thigh and corresponds to the middle section of the common femoral vein. The flexible pressure adjustment units are detachably connected to the medical elastic stocking body through an external fixation ring.

[0009] Preferably, the signal processing and transmission unit further includes: The outer casing has a switch and warning module on its outer surface and a main board circuit inside its cavity. The motherboard circuit integrates a multi-path selection module, an analog signal processing module, a beamforming module, an IQ module, an algorithm storage module, a micro control chip module, a wireless transmission module, a heat dissipation device, a battery, and a power converter. The multi-path selection module is used to receive the ultrasonic echo signal collected by the patch ultrasonic transducer unit and the resistance signal transmitted by the miniature temperature sensor and the miniature heating plate, and the multi-path selection module is used to alternately select the signals collected from multiple zones.

[0010] Preferably, the central monitoring and early warning unit is one or more of a tablet computer, a monitor, a smartphone, and a cloud server, used to realize the full recording of ultrasonic monitoring data, elasticity adjustment records, risk level changes, remote monitoring, and historical trajectory query, and the central monitoring and early warning unit supports drive switching and manual adjustment of elasticity gradient.

[0011] This application also provides a method for using intelligent pressure-regulating elastic stockings for the lower limbs with integrated ultrasound monitoring, including the following steps: Step 0: The medical elastic stockings are worn on the user's lower limbs to fix the patch ultrasound transducer units, flexible pressure adjustment units, and signal processing and transmission units. Specifically, during wear, the four patch ultrasound transducer units are placed in the internal fixation chamber, and the acoustic windows are attached to the skin surfaces of the middle segments of the posterior tibial vein, popliteal vein, lower femoral vein, and common femoral vein of the user's lower limbs using coupling gel. A shape memory polymer flexible ring strip is attached to the patch ultrasound transducer units via an external fixation ring and is tightly fitted to the outer surface of the medical elastic stockings without affecting blood circulation in the lower limbs. The signal processing and transmission unit is placed in the external fixation chamber and connected to each patch ultrasound transducer unit and the flexible pressure adjustment unit. Step 1: Turn on each patch ultrasonic transducer unit, flexible pressure adjustment unit, and signal processing and transmission unit, and each performs automatic initialization operations; enter the user's basic information through the central monitoring and early warning unit; Step 2: The baseline blood flow parameters of the user's lower limb veins at rest are collected by four patch ultrasound transducer units. The signal processing and transmission unit calibrates the individualized risk assessment threshold based on the blood flow baseline parameters using a pre-stored risk level-adjustment amplitude mapping algorithm. The elastic stockings intelligent gradient adjustment module maintains a basic elastic gradient in each zone, specifically 25 mmHg in zone A, 20 mmHg in zone B, 16.2 mmHg in zone C, and 10 mmHg in zone D. Step 3: When the user sits or lies down for a long time, causing changes in the blood flow status of the lower limbs, the four patch ultrasound transducer units alternately collect the ultrasound echo signals of the lower limb venous hemodynamics at fixed time intervals, and transmit them to the signal processing and transmission unit for processing to obtain accurate ultrasound data. Step 4: The algorithm storage module determines the DVT risk level based on the calibrated risk level-adjustment amplitude mapping algorithm and the accurate ultrasound data. Based on the determined DVT risk level, the mapping algorithm is called to generate the corresponding graded pressure adjustment strategy, and the adjustment strategy is transmitted to the micro control chip module simultaneously. Step 5: The micro control chip module drives the corresponding flexible pressure regulating unit to perform targeted or global gradient pressurization according to the pressure regulation strategy. At the same time, it collects temperature and elasticity feedback signals in real time through micro temperature sensors and micro tension strain gauges to perform closed-loop calibration of the pressurization process to ensure pressurization accuracy. Step 6: The patch ultrasound transducer unit continuously collects lower limb venous hemodynamic data after pressurization. After being processed by the signal processing and transmission unit, the data is transmitted to the algorithm storage module. The algorithm storage module re-determines the DVT risk level based on the processed data. If the risk level drops back to level 0, the micro control chip module will perform a pressure holding operation. If the risk level remains unchanged, the current adjustment strategy will be implemented with a slight adjustment of 2%. If the risk level increases, the pressure-intensifying strategy will be upgraded, and the early warning module will be triggered; If excessive pressure is detected, immediately perform an emergency pressure relief procedure; Step 7: Upload the data from Steps 2 to 6 in real time to the central monitoring and early warning unit via the wireless transmission module to achieve full data recording, remote monitoring and historical trajectory query. At the same time, the central monitoring and early warning unit retains manual intervention authority, which can switch driving modes and adjust elastic gradient.

[0012] Preferably, in step four above, the DVT risk level is divided into levels 0-3, and the judgment criteria are as follows: When the blood flow parameters in the ultrasound data are within the normal physiological range, the stasis index is <0.8, and there is no hypoechoic filling in the venous lumen, it is judged as grade 0; When a single parameter in the ultrasound data exceeds the individualized risk assessment threshold, specifically, a 20% decrease in blood flow velocity from baseline, a stasis index of 0.8–1.2, venous diameter dilation of <30%, and no hypoechoic filling in the venous lumen, it is assessed as Grade 1; When multiple parameters in the ultrasound data are abnormal, specifically, blood flow velocity decreases by more than 30%, stasis index is >1.2, venous diameter dilation is 30% ≤ 50%, and cloud-like fine echogenic spots appear in the venous lumen, it is judged as grade 2; When ultrasound data shows flocculent or clump-like hypoechoic areas in the venous lumen, sparse or absent blood flow signals, and significant dilation of the venous diameter ≥50%, it is classified as grade 3.

[0013] Preferably, in step four above, the graded pressure regulation strategy corresponding to the DVT risk level is as follows: When the DVT risk level is 0 and a single ultrasound parameter exceeds the threshold for 3 consecutive zones, the threshold instant adjustment mode is triggered, which starts a low-amplitude stepwise temperature increase only for the corresponding target zone, with an amplitude of 3 to 5°C per level and a 5-second pause after each temperature increase, to achieve small-amplitude pressure prevention. When the DVT risk level is Level 1, local targeted adjustment is triggered, with the corresponding zonal base gradient increased by 10% to 15%, the maximum increase in a single zonal gradient being 3 mmHg, and adjacent zonal gradients being increased by 5% simultaneously. When the DVT risk level is level 2, all zones are coordinated to adjust, the base gradient is increased by 20% to 25%, and the maximum increase in a single zone is 6 mmHg. When the DVT risk level is level 3, an emergency linkage adjustment is triggered, the basic gradient is increased by 30% but not exceeding the safety limit, and the early warning module and emergency data push are triggered simultaneously, and all target partitions are fully pressurized.

[0014] Preferably, in step five above, the pressure-driving body of the flexible pressure regulating unit is a shape memory polymer flexible annular strip, and the pressure regulating strategy pauses for 5 seconds after each stage of heating to perform closed-loop calibration. The closed-loop calibration process includes: The miniature temperature sensor collects the temperature of the shape memory polymer flexible annular strip in real time. After being processed by the signal processing and transmission unit, the temperature is fed back to the algorithm storage module and compared with the preset target temperature of 45-55℃. If the temperature is too high, the input voltage is reduced or the power supply is stopped; if the temperature is too low, the input voltage is increased. The micro tension strain gauge collects the contraction tension of the shape memory polymer flexible annular strip in real time. The signal processing and transmission unit converts it into the actual elastic force value and feeds it back to the algorithm storage module. It is compared with the preset target elastic force value. If the deviation exceeds ±1 mmHg, the next stage of temperature increase is finely adjusted by ±1℃ to calibrate the pressurization accuracy.

[0015] Preferably, in step six above, the criteria for determining the excessive compression state are: the pressure monitoring value of the micro-tension strain gauge exceeds the medical level 3 DVT prevention pressure threshold, i.e., ≤30mmHg in the calf and ≤15mmHg in the proximal thigh, or ultrasound monitoring shows a sudden reduction in venous diameter of >30%; In step six, the emergency pressure relief operation is as follows: the micro control chip module outputs a reverse heating command, heating by 2-3°C per stage and maintaining for 8 seconds, driving the shape memory polymer flexible annular strip gradient to reset and fall back to the basic elastic gradient.

[0016] By adopting the above technical solution, the beneficial effects achieved by the present invention are as follows: This invention achieves integrated "monitoring-early warning-intervention" through an innovative closed-loop linkage mode. It uses ultrasound monitoring to quantify blood flow indicators as the core trigger signal, effectively breaking through the technical barriers of traditional ultrasound being used only for diagnosis and elastic stockings only achieving passive prevention. Through closed-loop control, it completes dynamic risk adaptation and adjustment, significantly improving the timeliness and accuracy of DVT prevention.

[0017] This invention adopts a differentiated driving scheme, which takes into account both the simplification of the driving structure and the adaptability of application scenarios: the core optimizes the design of the SMP driving component, which can efficiently adapt to static prevention scenarios due to its outstanding advantages of extremely simple principle, fewest components, and low integration difficulty; at the same time, it provides multiple driving schemes, which can be flexibly selected according to the zonal pressure characteristics, applicable population and application scenarios, comprehensively covering the DVT prevention needs of all scenarios such as perioperative period, home, and long-term bed rest, with stronger adaptability.

[0018] This invention achieves precise and controllable compression, balancing safety and comfort: it employs a combination of step-by-step progressive compression and zoned targeted adjustment to effectively prevent sudden pressure changes from irritating veins; coupled with built-in multiple safety protection logics, it strictly limits the upper limit of elasticity and the skin's safe pressure threshold, ensuring safety while enhancing preventative effects. Furthermore, the drive component is mounted on the outer surface, preserving the structure of the compression stockings, ensuring a comfortable fit, and not hindering daily activities. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure of the medical elastic stocking of the present invention.

[0020] Figure 2 This is a schematic diagram of the flexible pressure regulating unit of the present invention.

[0021] Figure 3 This is a schematic diagram of the internal fixation chamber and patch ultrasonic transducer unit structure of the present invention.

[0022] Figure 4 This is a schematic diagram of the housing structure of the signal processing and transmission unit of the present invention.

[0023] Figure 5 This is a schematic diagram of the internal mainboard circuit structure of the signal processing and transmission unit of the present invention.

[0024] Figure 6 This is a flowchart of the process of the present invention.

[0025] In the diagram: 100, Medical elastic stocking body; 101, External fixation chamber; 102, Patch ultrasonic transducer lead wire; 103, Stocking cuff lead wire ring; 104, Elastic stocking intelligent gradient adjustment module; 105, Intelligent gradient adjustment module lead wire; 106, Area A; 107, Area B; 108, Area C; 109, Area D; 200, Internal fixation chamber; 300, Patch ultrasonic transducer unit; 400, Acoustic window surface; 500, Shape memory polymer flexible annular strip; 501, Micro heating plate; 502, Micro... 503. Temperature sensor; 504. Miniature tension strain gauge; 605. External fixing ring; 606. Signal processing and transmission unit; 607. Housing; 608. Switch; 609. Early warning module; 600. Multi-path selection module; 601. Analog signal processing module; 602. Beamforming module; 603. IQ module; 604. Algorithm storage module; 605. Miniature control chip module; 616. Wireless transmission module; 617. Heat dissipation device; 618. Battery; 619. Power converter. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification. Example 1

[0028] like Figures 1-5 As shown, this invention provides a lower limb intelligent pressure-adjustable elastic stocking with integrated ultrasound monitoring, including a medical elastic stocking body 100, a patch ultrasonic transducer unit 300, an elastic stocking intelligent gradient adjustment module 104, a signal processing and transmission unit 600, and a central monitoring and early warning unit. The signal processing and transmission unit 600 is connected to the patch ultrasonic transducer unit 300 via a patch ultrasonic transducer wire 102; the signal processing and transmission unit 600 is connected to the elastic stocking intelligent gradient adjustment module 104 via an intelligent gradient adjustment module wire 105, both of which are flexible wires; the signal processing and transmission unit 600 and the central monitoring and early warning unit are connected via wireless communication (WiFi).

[0029] like Figure 1 and Figure 3 As shown, the inner surface of the medical elastic stocking 100 is provided with four internal fixation chambers 200. Each internal fixation chamber 200 has an acoustic window on its surface for corresponding to the acoustic window surface 400 of the patch ultrasound transducer unit 300, so as to ensure that the acoustic window surface 400 of the patch ultrasound transducer unit 300 is fully exposed and accurately monitors the target vein. The outer surface of the medical elastic stocking 100 is provided with at least one external fixation chamber 101. The cuff of the medical elastic stocking 100 is provided with a cuff guide ring 103 for combing the guide wire.

[0030] As a further step, four patch ultrasound transducer units 300 are respectively installed in the four internal fixation chambers 200 of the medical elastic stocking body 100, and are arranged sequentially from top to bottom along the anatomical sites of the main veins of the lower limb. The acoustic window surface 400 of each patch ultrasound transducer unit 300 is attached to the skin through coupling gel, which is used for targeted, continuous, non-invasive quantitative acquisition of ultrasound echo signals of lower limb venous hemodynamics.

[0031] In a preferred embodiment, a single patch ultrasound transducer unit 300 is rectangular in shape, approximately 4 cm long, 2 cm wide, and 0.5 cm thick; its frequency range is approximately 5-10 MHz, and its scanning depth is 5-10 cm. Four patch ultrasound transducer units 300 are intermittently attached to the skin surface of the middle segment of the common femoral vein, the middle and lower segment of the femoral vein, the middle segment of the popliteal vein, and the middle segment of the posterior tibial vein, from top to bottom, along the anatomical locations of the lower limb veins.

[0032] Four patch ultrasound transducer units 300 alternately emit ultrasound waves to the target vein at fixed time intervals and receive echo signals from the monitored vein, and transmit the echo signals to the signal processing and transmission unit 600. The signal processing and transmission unit 600 automatically calculates hemodynamic parameters such as the peak systolic velocity Vmax, vein diameter D, and blood stasis index of the target vein based on the received echo signals, where the blood stasis index = vein diameter / blood flow velocity.

[0033] Furthermore, the intelligent gradient adjustment module 104 for elastic stockings includes multiple flexible pressure adjustment units detachably connected to the outer surface of the medical elastic stocking body 100. These flexible pressure adjustment units correspond one-to-one with the monitoring points of multiple patch ultrasonic transducer units 300. The intelligent gradient adjustment module 104 is used to implement targeted, graded, and dynamic adjustment of the gradient pressure for the prevention and treatment of lower extremity venous thrombosis. It is worth noting that the intelligent gradient adjustment module 104 is based on a modification of traditional medical gradient elastic stockings, retaining the fundamental characteristic of decreasing elasticity from the ankle to the proximal thigh. It integrates multiple flexible pressure adjustment components and can select an appropriate driving scheme according to the scenario requirements to achieve local / global, step-like dynamic adjustment of the elasticity gradient.

[0034] like Figure 1 As shown, in a preferred embodiment, the elastic stocking intelligent gradient adjustment module 104 divides the elastic stocking into four pressure adjustment zones, or flexible pressure adjustment units, according to the common sites of lower extremity venous thrombosis and monitoring needs. Each zone corresponds one-to-one with the monitoring point of the patch ultrasonic transducer unit 300. Specifically: Four flexible pressure adjustment units are respectively formed on the medical elastic stocking body 100 to form area A 106, which is adapted to the middle section of the calf and corresponds to the middle section of the posterior tibial vein; area B 107, which is adapted to the popliteal fossa and corresponds to the middle section of the popliteal vein; area C 108, which is adapted to the middle and lower section of the thigh and corresponds to the middle and lower section of the femoral vein; and area D 109, which is adapted to the upper section of the thigh and corresponds to the middle section of the common femoral vein. Each flexible pressure adjustment unit is detachably connected to the medical elastic stocking body 100 through a corresponding external fixation ring 504.

[0035] like Figure 2As shown, as a further step, each flexible pressure regulating unit includes: a shape memory polymer flexible annular strip 500, a micro heating element 501, a micro temperature sensor 502, a micro tension strain gauge 503, and an outer fixing ring 504; the micro heating element 501, the micro temperature sensor 502, and the micro tension strain gauge 503 are all electrically connected to the signal processing and transmission unit 600.

[0036] As a preferred embodiment, the shape memory polymer (SMP) flexible annular strip is used as the pressure-driven body. It is made of thermally responsive polycaprolactone and the annular length is adjusted according to the leg circumference of the section. It is about 3 cm wide and about 1 mm thick. Its shrinkage rate is 15% to 20%, and it maintains pressure stability ≤ ±1 mmHg / 8h. The glass transition temperature (Tg) is 45 to 55°C (suitable for human safety range to avoid burns). The surface is plasma passivated to prevent corrosion from body fluids and skin irritation.

[0037] When heated by the micro heating element 501, the shape memory polymer flexible annular strip 500 transforms from martensitic to austenitic phase as the temperature rises. The molecular chains tend to align more regularly, driving the annular strip to contract precisely along its length. The tension generated by the contraction is transmitted to the skin through the outer surface of the elastic stocking, achieving the purpose of localized pressure. When reverse heating is initiated, the SMP strip undergoes a gradient phase transition and gradually returns to its original position. The tension decreases step by step with the phase transition, and the corresponding pressure falls back according to the gradient until the SMP strip is completely relaxed and the pressure is completely returned to its original position.

[0038] In a preferred embodiment, the micro heating element 501 is made of flexible polyimide (PI) heating element and is attached to the outer surface of the shape memory polymer flexible annular strip 500 to transfer heat energy to the shape memory polymer flexible annular strip 500. The micro heating element 501 is sized to fit perfectly with the SMP strip and has a thickness of 0.3 mm; it integrates a mesh-like ultrafine metal heating wire, which is made of copper-nickel alloy with a wire diameter of 0.02 mm, and is evenly arranged at equal intervals to form a heating circuit.

[0039] When the signal processing and transmission unit 600 outputs a graded voltage command, current flows through the wires to the metal heating wire, generating Joule heating. The heat is rapidly conducted through the polyimide substrate to the thermally conductive silicone layer on the surface, and then evenly transferred to the SMP flexible strip body, achieving a step-by-step temperature increase of the strip. Since the resistance of the metal heating wire is constant, the current can be precisely controlled by adjusting the input voltage, thereby achieving precise regulation of the heat generation and heating rate. Combined with the temperature sensor that is attached to the surface, a closed-loop temperature control is formed, which can ensure that the heating temperature is stable within the target range (45-55℃), which can meet the phase change requirements of the SMP material and avoid skin burns caused by excessive temperature.

[0040] As a preferred embodiment, the miniature temperature sensor 502 is made of a surface-mount NTC thermistor with dimensions of 2mm×1mm×0.5mm, a measurement range of 25~60℃, and a response time of ≤0.1s. The miniature temperature sensor (502) is attached to the center of the shape memory polymer flexible annular strip (500) with medical-grade thermally conductive adhesive to collect the temperature data of the shape memory polymer flexible annular strip (500) in real time, ensuring accurate temperature control.

[0041] Specifically, after the miniature temperature sensor 502 is attached to the SMP strip, it can synchronously sense the temperature change of the SMP strip and convert it into a resistance signal, which is transmitted to the signal processing and transmission unit 600 via a flexible wire. The signal processing module converts the resistance signal into a precise temperature value through a built-in signal conversion circuit and compares it with the preset target temperature (45-55℃) and the step temperature increase range. If the actual temperature is lower than the target value, the miniature control chip module 609 in the signal processing and transmission unit 600 increases the input voltage of the miniature heating element 501 to increase the heat generation; if the actual temperature is higher than the target value, the voltage is reduced or the power supply is stopped, thus forming a closed-loop temperature control of "acquisition-conversion-comparison-regulation". At the same time, during the pressure maintenance phase, the strip tension change caused by temperature fluctuations can be monitored in real time, providing data support for micro-temperature compensation commands.

[0042] In a preferred embodiment, a miniature tension strain gauge 503 is embedded inside the shape memory polymer flexible annular strip 500. It has a size of 1mm × 0.8mm × 0.1mm, a measurement range of 0 to 5N, and an accuracy of ±0.01N. It is used to collect the tension data of the shape memory polymer flexible annular strip 500 in real time and convert it into the corresponding elastic force value and feed it back to the signal processing and transmission unit 600 to assist in calibrating the pressure accuracy.

[0043] Specifically, the micro-tension strain gauge 503 is integrally molded with the SMP strip, without affecting the strip's deformation performance and shape memory effect. Its working principle is based on the metal strain resistance effect, where the resistance of a metal conductor changes systematically with its deformation. The core of the strain gauge is an ultra-fine constantan alloy sensitive grid with a wire diameter of 0.005mm, integrated into a flexible substrate with a specific texture. After being integrally molded with the SMP strip, it can synchronously shrink or relax along with the strip. When the shape memory polymer flexible annular strip 500 is heated and shrinks, the sensitive grid is stretched, increasing in length and decreasing in cross-sectional area, resulting in a linear increase in resistance. When the shape memory polymer flexible annular strip 500 relaxes and resets, the sensitive grid returns to its original shape, the resistance returns to its initial value, and the change in resistance has a fixed quantitative proportional relationship with the strip's deformation tension.

[0044] As a further step, the resistance change signal collected by the micro tension strain gauge 503 is transmitted to the signal processing and transmission unit 600 via a flexible wire, and after conversion, amplification and filtering, it is converted into a precise tension value; then, combined with the SMP strip specifications and elastic stocking fabric characteristics, it is converted into the elasticity value of the corresponding zone, providing core feedback data for the accuracy calibration of stepped pressurization and the fluctuation compensation during the pressure maintenance stage.

[0045] In a preferred embodiment, the external fixation ring 504 adopts an integrated design of ring-shaped fitting and detachable adjustable Velcro. The Velcro can be ring-shaped to fit different leg circumferences of patients. The Velcro is made of medical-grade nylon, with the same width as the SMP strip. The hook side is sewn to the back of one end of the shape memory polymer flexible ring strip 500, and the rough side is sewn to the front of the other end of the shape memory polymer flexible ring strip 500. This ensures that the SMP strip is stable and does not shift during pressure application, taking into account fixation reliability, ease of wear, and adjustment flexibility, while adapting to different lower limb leg circumferences of patients.

[0046] Furthermore, the shape memory polymer flexible ring band 500 is fixed in a ring along the outer surface of the elastic stockings in areas A 106, B 107, C 108, and D 109. A 0.3mm thick ultra-thin breathable silicone layer is laminated to the inner side of the band, improving the fit with the outer surface of the elastic stockings and the skin, reducing slippage and friction, and avoiding localized skin pressure. Additionally, the connection between the SMP band and the Velcro is reinforced with both ultrasonic welding and medical sutures, effectively preventing the Velcro from detaching during stretching and contraction. This allows for quick and easy application and removal by the patient, facilitating cleaning, maintenance, and replacement without damaging the structure of the elastic stockings.

[0047] As a further step, the signal processing and transmission unit 600 is located in the external fixation chamber 101 of the medical elastic stocking body 100; and the signal processing and transmission unit 600 is used to receive the ultrasonic echo signals collected by each patch ultrasonic transducer unit 300 and the resistance signals transmitted by the elastic stocking intelligent gradient adjustment module 104, and after processing and analysis, generate and output adjustment commands to the elastic stocking intelligent gradient adjustment module 104.

[0048] Specifically, the signal processing and transmission unit 600 receives the ultrasonic echo analog signal collected by the patch ultrasonic transducer unit 300, and the resistance signal transmitted by the miniature temperature sensor 502 and the miniature tension strain gauge 503. After signal processing and analysis, it outputs accurate ultrasonic detection data, temperature values, and elasticity values. Subsequently, it matches the output parameters with the preset DVT risk level and outputs precise adjustment commands accordingly, linking the elastic stocking intelligent gradient adjustment module 104 and various feedback actuators to achieve dynamic control of the elasticity gradient. At the same time, through multiple feedback verifications and multi-level safety mechanisms, it ensures the system's adjustment accuracy, operational stability, and safety. In addition, the signal processing and transmission unit 600 can also synchronously upload ultrasonic monitoring data, elasticity adjustment records, and risk level changes to the central monitoring and early warning unit via wireless (WIFI) connection.

[0049] like Figure 4 and Figure 5 As shown, in a preferred embodiment, the signal processing and transmission unit 600 includes: a housing 601, with a switch 602 and an early warning module 603 on the outer surface of the housing 601, and a motherboard circuit in the inner cavity of the housing 601; the motherboard circuit integrates a multi-path selection module 604, an analog signal processing module 605, a beamforming module 606, an IQ module 607, an algorithm storage module 608, a micro control chip module 609, a wireless transmission module 610, a heat dissipation device 611, a battery 612, and a power converter 613.

[0050] The main board circuit is connected to the patch ultrasonic transducer unit 300, the miniature heating element 501, the miniature temperature sensor 502, and the miniature tension strain gauge 503 via wires.

[0051] In a preferred embodiment, the early warning module 603 is an audible and visual alarm.

[0052] The multi-path selection module 604 receives the analog ultrasonic echo signal acquired by the patch ultrasonic transducer unit 300, as well as the resistance signals transmitted by the miniature temperature sensor 502 and the miniature heating element 501. This module performs zoned selection processing on the aforementioned multiple signal sets, allowing only one zone's signal to pass through at any given time, and then transmits it to the analog signal processing module 605. The signal switching process of the multi-path selection module 604 automatically alternates at preset time intervals, thereby achieving orderly acquisition and path allocation of multiple sets of detection signals.

[0053] Analog signal processing module 605: The ultrasonic and resistance signals are fed into the analog signal processing module. The analog signal is amplified by low noise, filtered by noise reduction, amplified by gain, converted from analog to digital signal by Wheatstone bridge circuit, and finally converted into a digital signal and transmitted to the beamforming module. The resistance signal is converted into accurate temperature and tension values ​​and transmitted to the algorithm storage module.

[0054] The analog signal processing module 605 receives the ultrasonic signal and the resistance signal after being filtered by the multi-path selection module 604, and performs low-noise amplification, noise reduction filtering and gain amplification on them in sequence, and then completes the signal conversion in combination with the Wheatstone bridge circuit. Among them, the ultrasonic analog signal is converted into a digital signal after analog-to-digital conversion and transmitted to the beamforming module 606, while the resistance signal is converted to obtain accurate temperature and tension values ​​and transmitted to the algorithm storage module 608.

[0055] The beamforming module 606, based on the core principle of time delay summation, calculates and compensates for the time difference between the arrival of ultrasonic waves from the target scattering point to different array elements. This allows signals from the same scattering point to be added in phase during superposition, thereby enhancing the signal energy. Meanwhile, noise and interference signals from other directions are effectively suppressed due to phase differences, thus improving system resolution and imaging quality, optimizing the output effect of ultrasonic images, and transmitting the synthesized beam signal to the IQ module 607.

[0056] The IQ module 607 is responsible for receiving the beam-synthesized radio frequency signal, performing IQ demodulation and low-pass filtering on it, and converting it into a low-frequency baseband signal containing phase information, which significantly reduces the data rate and provides accurate data support for blood flow imaging and motion analysis based on the Doppler effect.

[0057] The algorithm storage module 608 is responsible for determining the DVT risk level and generating a pressure regulation strategy based on the processed ultrasound echo signal. Specifically, it first normalizes the collected ultrasound blood flow baseline indicators and extracts the threshold of a single indicator (calibrated based on clinical DVT diagnosis and treatment guidelines and user-personalized baseline data) to form a dual early warning data system of "threshold trigger signal + risk level trigger signal" and outputs a DVT risk level of 0 to 3. Then, based on the output DVT risk level, it triggers the corresponding pressure regulation level to generate a pressure regulation strategy that matches the risk level.

[0058] Specifically, the criteria for determining the risk level of DVT from level 0 to 3 are as follows: When ultrasound parameters are within the normal range, stasis index <0.8, and there is no hypoechoic filling of the lumen, it is judged as DVT risk level 0 (low risk).

[0059] When a single ultrasound parameter exceeds the threshold (blood flow velocity decreases by 20% from baseline, stasis index 0.8–1.2, venous diameter dilation <30%), and there is no hypoechoic filling of the lumen, it is judged as DVT risk level 1 (medium risk).

[0060] When multiple ultrasound parameters are abnormal (blood flow velocity decreases by more than 30%, stasis index > 1.2, 30% ≤ venous diameter dilation < 50%), and cloud-like fine light spots accumulate in the lumen (early thrombosis characteristic), it is judged as DVT risk level 2 (high risk).

[0061] When ultrasound shows flocculent or clump-like hypoechoic areas in the venous lumen, sparse or absent blood flow signals, and significant dilation of the venous diameter ≥50%, which are consistent with the characteristics of acute thrombosis, it is judged as DVT risk level 3 (very high risk).

[0062] Based on the above DVT risk levels of 0 to 3, the corresponding pressure regulation levels are as follows: When the risk level is 0 and a single ultrasound parameter exceeds the threshold for 3 consecutive zones, it is determined to be "sudden minor blood flow stasis". The pressure regulation level triggers the threshold instant adjustment mode: only the corresponding target zone is activated with low-amplitude step temperature increase (single-level temperature increase of 3-5℃) to achieve small pressure increase prevention and avoid over-adjustment.

[0063] When the risk level is level 1, it is judged as "gradual stagnation risk". The pressure adjustment level triggers local targeted adjustment: the basic gradient of the corresponding zone is increased by 10% to 15%, the maximum increase of a single zone is 3 mmHg, and the adjacent zones are simultaneously and slightly increased by 5% to maintain the overall elasticity reduction gradient.

[0064] When the risk level is level 2, it is judged as "early warning of thrombosis". The pressure regulation level triggers the coordinated regulation of all zones: the baseline gradient is increased by 20% to 25%, and the maximum increase in a single zone is 6 mmHg, which enhances the venous return dynamics of the lower extremities.

[0065] When the risk level is level 3, it is determined to be "acute thrombotic precursor". The pressure regulation level is triggered to adjust the emergency linkage: the basic gradient is increased by 30% (not exceeding the safety limit), and the audible and visual alarm module (i.e., the early warning module 603) and the data emergency push are activated at the same time. All target areas are fully pressurized to buy time for medical intervention.

[0066] The micro control chip module 609 is responsible for instruction generation and drive execution control. It receives the pressure adjustment strategy transmitted by the algorithm storage module 608 and generates hierarchical control instructions adapted to the elastic stocking intelligent gradient adjustment module 104, including heating voltage instructions, pressure holding time instructions, and pressure relief reset instructions. At the same time, it dynamically adjusts the output voltage through the power supply battery to ensure the accurate execution of various instructions.

[0067] The instruction execution process is as follows: Heating stage: Output graded voltage (0.5~3V) to the micro heating element, and adjust the heating rate by 3~5℃ per grade. After each heating stage, maintain a stable period of 5s-10s (preferably 5s) to avoid sudden temperature rise affecting the performance of SMP material and skin comfort. During the pressure holding stage: After the miniature heating element 501 stops working, it outputs a standby command, and only the miniature temperature sensor 502 and the miniature tension strain gauge 503 maintain low power operation to monitor pressure fluctuations in real time; Decompression phase: After receiving the "ultrasound blood flow parameter recovery" signal from the algorithm storage module 608, a gradient reset command (i.e., reverse heating command) is output. The SMP strip is driven to decompress and reset smoothly by using a reverse adjustment method of 2-3℃ per level and maintaining for 8s.

[0068] In a preferred embodiment, the micro control chip module 609 collects control effect data in real time through three feedback channels, dynamically optimizes and corrects the adjustment commands, ensures pressurization accuracy and safety of use, and forms a secondary closed-loop control.

[0069] The three-feedback verification and instruction optimization are detailed below: First feedback channel (tension-elasticity feedback): The miniature tension strain gauge 503 collects the contraction tension signal of the SMP strip and transmits it to the signal processing and transmission unit 600 via a flexible wire. The analog signal processing module 305 converts the resistance change signal into a tension value and, in combination with the SMP strip specifications and the characteristics of the elastic stocking fabric, calculates it into an actual elasticity value, which is then compared with the preset target elasticity value. If the deviation exceeds ±1 mmHg, the miniature control chip module 609 immediately fine-tunes the next stage of heating amplitude (±1℃) to achieve pressure accuracy calibration.

[0070] The second feedback channel (temperature-status feedback): The miniature temperature sensor 502 collects the temperature of the SMP strip body in real time and feeds it back to the algorithm storage module 608 to compare with the target temperature range (45~55℃); if the temperature exceeds 55℃, the miniature control chip module 609 immediately reduces the input voltage of the miniature heating element 501 or cuts off the power supply to prevent skin burns; if the temperature is lower than the target range, the input voltage is increased to increase the heat generation.

[0071] The third feedback channel (ultrasound-effect feedback): After the pressure adjustment is started, the patch ultrasound transducer unit 300 samples and provides feedback on the changes in lower limb blood flow indicators in real time; if the indicators improve, the micro control chip module 609 maintains the current pressure; if the indicators do not improve significantly, the pressure value is finely adjusted by 2%; if the indicators deteriorate, the adjustment strategy is upgraded and the alarm prompts are strengthened.

[0072] In a preferred embodiment, the microcontroller chip module 609 incorporates multiple safety protection logics to manage and regulate risks throughout the process, preventing vascular compression damage. Specifically: Pressure safety threshold control: If the actual elastic force value calculated by tension feedback exceeds the medical level 3 DVT prevention standard (lower leg ≤30mmHg, proximal thigh ≤15mmHg) or the 35kPa skin pressure threshold, an emergency pressure relief command is immediately executed, driving the SMP strip to start reverse heating and reset, quickly returning to the safe baseline gradient.

[0073] Vascular status management: If ultrasound monitoring shows a sudden reduction in venous diameter of >30%, it is determined to be "excessive compression", and the adjustment unit is immediately triggered to stop, return to the baseline gradient and start an alarm.

[0074] The wireless transmission module 610 is responsible for transmitting the ultrasound data or image information processed by the IQ module 607 wirelessly, in real time and reliably to the central monitoring and early warning unit via Bluetooth or WIFI, realizing fully wireless, mobile and intelligent interaction between the signal processing and transmission unit 600 and the central monitoring and early warning unit.

[0075] The heat dissipation device 611 integrates copper foil, metal bracket or miniature heat spreader inside the signal processing and transmission unit 600, which can quickly diffuse heat from the heat source to the entire surface of the housing 601, increase the heat dissipation area, avoid low-temperature burns to human skin during use, and improve wearing safety and comfort.

[0076] The 612 battery uses lithium polymer material, has a voltage of 7.4V, a capacity of 1650mAh, and a single-charge runtime of about 3 hours. It can output clean, low-ripple DC power and, together with a precision power management circuit, provides a stable voltage to the main board circuit and the surface mount ultrasonic transducer unit 300, ensuring the continuous and stable operation of the surface mount ultrasonic system.

[0077] The power converter 613 is a boost converter, which includes an inductor, a switching transistor, a diode, and a capacitor. The switching transistor quickly turns the inductor on and off to store and release energy, generating a DC voltage at the output that is higher than the input voltage. This allows for the acquisition of high signal-to-noise ratio ultrasound images, extending battery life and reducing component heat generation.

[0078] The central monitoring and early warning unit is an independent mobile terminal or central monitoring station software, wirelessly connected to the signal processing and transmission unit 600. It receives ultrasound monitoring data, elasticity adjustment records, and risk level changes transmitted by the signal processing and transmission unit 600 via Wi-Fi, enabling full data recording, remote monitoring, and historical trajectory querying. It also retains manual intervention permissions, allowing patients and medical staff to switch drive modes and adjust elasticity gradients according to actual needs, adapting to various application scenarios such as home monitoring and post-operative hospital management.

[0079] In a preferred embodiment, the central monitoring and early warning unit is one or more of a tablet computer, a monitor, a smartphone, and a cloud server.

[0080] Example 2 like Figure 6 As shown, this invention also proposes a method for operating intelligent pressure-adjustable elastic stockings for the lower limbs with integrated ultrasound monitoring, comprising the following steps: Step 0: The medical elastic stocking 100 is worn on the user's lower limbs to fix the patch ultrasound transducer unit 300, the flexible pressure adjustment unit, and the signal processing and transmission unit 600. Specifically, during wear, the four patch ultrasound transducer units 300 are placed in the internal fixation chamber 200, and the acoustic windows 400 are attached to the skin surface of the middle segment of the posterior tibial vein, the middle segment of the popliteal vein, the middle and lower segment of the femoral vein, and the middle segment of the common femoral vein in the user's lower limbs through coupling gel. The shape memory polymer flexible annular strip 500 is attached to the patch ultrasound transducer unit 300 through the external fixation ring 504 and is tightly attached to the outer surface of the medical elastic stocking 100 without affecting the blood circulation of the lower limbs. The signal processing and transmission unit 600 is placed in the external fixation chamber 101 and connected to each patch ultrasound transducer unit 300 and the flexible pressure adjustment unit.

[0081] Step 1: Turn on each patch ultrasonic transducer unit 300, flexible pressure regulating unit, and signal processing and transmission unit 600, and each performs automatic initialization operation; enter the user's basic information through the central monitoring and early warning unit.

[0082] Step 2: The blood flow baseline indicators of the user's lower limb veins at rest are collected by four patch ultrasound transducer units 300, and the received ultrasound echo signals are transmitted to the signal processing and transmission unit 600 through wires. After processing by the modules in the signal processing and transmission unit 600, the algorithm storage module 608 calibrates the individualized risk judgment threshold for the pre-stored risk level-adjustment amplitude mapping algorithm based on the processed blood flow baseline indicators, which serves as the basis for the user's personalized threshold calibration. In this step, the initial DVT risk level is determined to be level 0. Each monitoring unit enters a low-power standby monitoring mode. The elastic stocking intelligent gradient adjustment module 104 maintains the basic elastic gradient in each zone, specifically: Zone A 25 mmHg, Zone B 20 mmHg, Zone C 16.2 mmHg, and Zone D 10 mmHg. Simultaneously, the shape memory polymer flexible annular strip 500 is in a martensitic flexible relaxation state, the micro-heating element 501 is powered off and in standby mode, and the micro-tension strain gauge 503 completes zero-calibration.

[0083] Step 3: When the user sits or lies down for a long time, causing changes in the blood flow status of the lower limbs, the four patch ultrasound transducer units 300 alternately collect the ultrasound echo signals of the lower limb venous hemodynamics at fixed time intervals and transmit them to the signal processing and transmission unit 600 for processing, and finally output accurate ultrasound data. The specific process is as follows: the patch ultrasonic transducer unit 300 transmits the acquired signal to the multi-path selection module 604 via a wire. After path selection, it is sent to the analog signal processing module 605 to be converted into a digital signal, and then transmitted to the beamforming module 606 for signal enhancement. After enhancement, it is transmitted to the IQ module 607 for further processing, and finally, accurate ultrasonic data is obtained.

[0084] Step 4: The algorithm storage module 608 determines the DVT risk level based on the calibrated risk level-adjustment amplitude mapping algorithm and the accurate ultrasound data. Based on the determined DVT risk level, the mapping algorithm is called to generate the corresponding graded pressure adjustment strategy, and the adjustment strategy is transmitted to the micro control chip module 609 simultaneously. DVT risk levels are divided into 0-3, and the specific determination process is as follows: When the blood flow parameters in the ultrasound data are within the normal physiological range, the stasis index is <0.8, and there is no hypoechoic filling in the venous lumen, it is judged as grade 0; When a single parameter in the ultrasound data exceeds the individualized risk assessment threshold, specifically, a 20% decrease in blood flow velocity from baseline, a stasis index of 0.8–1.2, venous diameter dilation of <30%, and no hypoechoic filling in the venous lumen, it is assessed as Grade 1; When multiple parameters in the ultrasound data are abnormal, specifically, blood flow velocity decreases by more than 30%, stasis index is >1.2, venous diameter dilation is 30% ≤ 50%, and cloud-like fine echogenic spots appear in the venous lumen, it is judged as grade 2; When ultrasound data shows flocculent or clump-like hypoechoic areas in the venous lumen, sparse or absent blood flow signals, and significant dilation of the venous diameter ≥50%, it is classified as grade 3.

[0085] Based on the determined DVT risk level, the corresponding graded pressure regulation strategy is invoked as follows: When the DVT risk level is 0 and a single ultrasound parameter exceeds the threshold for 3 consecutive zones, the threshold instant adjustment mode is triggered, which starts a low-amplitude stepwise temperature increase only for the corresponding target zone, with an amplitude of 3 to 5°C per level and a 5-second pause after each temperature increase, to achieve small-amplitude pressure prevention. When the DVT risk level is Level 1, local targeted adjustment is triggered, with the corresponding zonal base gradient increased by 10% to 15%, the maximum increase in a single zonal gradient being 3 mmHg, and adjacent zonal gradients being increased by 5% simultaneously. When the DVT risk level is level 2, all zones are coordinated to adjust, the base gradient is increased by 20% to 25%, and the maximum increase in a single zone is 6 mmHg. When the DVT risk level is level 3, an emergency linkage adjustment is triggered, the basic gradient is increased by 30% but not exceeding the safety limit, and the early warning module 603 and emergency data push are triggered simultaneously, and all target partitions are fully pressurized.

[0086] Step 5: The micro control chip module 609 drives the corresponding flexible pressure regulating unit to perform targeted or global gradient pressurization according to the pressure regulation strategy. At the same time, it collects temperature and elasticity feedback signals in real time through the micro temperature sensor 502 and the micro tension strain gauge 503 to perform closed-loop calibration of the pressurization process to ensure pressurization accuracy. In this step, the pressure-driving body of the flexible pressure regulating unit is a shape memory polymer flexible annular strip 500. The micro control chip module 609 can output a heating voltage command to the corresponding partition according to the pressure regulation strategy provided by the algorithm storage module 608, so as to control the micro heating element 501 of the corresponding partition to heat up according to different levels of strategy, gradually raising the temperature of the SMP flexible strip to the rated temperature (maximum <55℃), triggering the strip phase change shrinkage.

[0087] During the execution of the temperature rise command, a 5-second pause is performed after each temperature rise stage to execute closed-loop calibration (i.e., feedback channel). The closed-loop calibration process includes: The temperature of the shape memory polymer flexible annular strip 500 is acquired in real time by a miniature temperature sensor 502. The temperature signal is converted into a resistance signal and transmitted via wires to the signal processing and transmission unit 600 for sequential processing by various modules. Finally, the processed temperature data is fed back to the algorithm storage module 608 and compared with a preset target temperature of 45–55°C. If the temperature is too high, the input voltage is reduced or the power supply is stopped; if the temperature is too low, the input voltage is increased. It should be noted that this closed-loop calibration corresponds to the second feedback channel.

[0088] The shrinkage tension of the shape memory polymer flexible annular strip 500 is acquired in real time by a micro tension strain gauge 503. The shrinkage tension signal is converted into a resistance signal, which is then processed by the signal processing and transmission unit 600 and converted into an actual elastic force value. This value is then fed back to the algorithm storage module 608 and compared with a preset target elastic force value. If the deviation exceeds ±1 mmHg, the next stage of temperature increase is finely adjusted by ±1℃ to calibrate the pressurization accuracy. It should be noted that this closed-loop calibration corresponds to the first feedback channel.

[0089] Step 6: The patch ultrasound transducer unit 300 continuously collects the lower extremity venous hemodynamic data after pressure is applied. After being processed by the signal processing and transmission unit 600, the data is transmitted to the algorithm storage module 608. The algorithm storage module 608 re-determines the DVT risk level based on the processed data. If the risk level drops back to level 0, the micro control chip module 609 receives the feedback signal and outputs a pressure holding duration command to perform the pressure holding operation; the micro heating element 501 stops working, and the SMP flexible strip cools down naturally to about 37°C with the body surface temperature, entering the austenitic stable state. It can maintain its current elasticity without continuous power supply, greatly reducing system power consumption and meeting the needs of continuous nighttime operation.

[0090] If the risk level remains unchanged, the current adjustment strategy will be slightly adjusted by 2%.

[0091] If the risk level increases, the pressure strategy is upgraded, and the early warning module 603 is triggered. Specifically, if the ultrasound blood flow parameters received by the algorithm storage module 608 indicate that the DVT risk level continues to worsen, feedback is sent to the microcontroller chip module 609 to trigger the auxiliary audible and visual alarm. The buzzer emits an alarm sound of ≥60dB, the LED warning light flashes continuously, and the ultrasound monitoring data, elasticity adjustment records, and changes in DVT risk level are simultaneously uploaded to the central monitoring and early warning unit via the wireless transmission module 610, prompting medical staff to intervene in a timely manner and buy valuable time for thrombosis prevention.

[0092] If excessive compression is detected, an emergency pressure relief operation is immediately executed. Specifically, if the pressure monitoring value of the micro-tension strain gauge 503 exceeds the medical level 3 DVT prevention pressure threshold (≤30 mmHg for the calf and ≤15 mmHg for the proximal thigh), or if ultrasound monitoring shows a sudden contraction of the venous diameter >30%, it is determined to be "excessive compression," and an emergency pressure relief and reset command is immediately executed. The emergency pressure relief operation is as follows: the micro-control chip module 609 outputs a reverse heating command, increasing the temperature by 2-3°C per stage and maintaining it for 8 seconds, driving the shape memory polymer flexible annular strip 500 to reset gradient back to the basic elastic gradient. An alarm procedure can also be added in this state.

[0093] Step 7: The data from Steps 2 to 6 are uploaded to the central monitoring and early warning unit for storage in real time via the wireless transmission module 610, enabling full data recording, remote monitoring, and historical trajectory query. At the same time, the central monitoring and early warning unit retains manual intervention authority, allowing for switching of drive modes and adjustment of elastic gradient.

[0094] In summary, the present invention has the following advantages: I. Innovative closed-loop linkage to achieve integrated "monitoring-early warning-intervention": Using ultrasound monitoring to quantify blood flow indicators as the core trigger signal, it breaks through the technical barriers of traditional ultrasound being used only for diagnosis and elastic stockings only achieving passive prevention. Through closed-loop control, it completes dynamic risk adaptation and adjustment, significantly improving the timeliness and accuracy of DVT prevention.

[0095] II. Differentiated driving solutions, balancing simplification and adaptability: The core optimized SMP driving component, with its advantages of "extremely simple principle, fewest components, and low integration difficulty", can be efficiently adapted to static prevention scenarios; at the same time, multiple driving solutions are provided, which can be flexibly selected according to the zonal pressure characteristics, applicable population and application scenarios, comprehensively covering the DVT prevention needs of all scenarios such as perioperative period, home, and long-term bed rest.

[0096] III. Precise and controllable compression, balancing safety and comfort: Employing a stepped, progressive compression and zoned targeted adjustment, it avoids sudden pressure changes that could irritate veins. Multiple safety protection mechanisms strictly limit the upper limit of elasticity and the skin's safe pressure threshold, ensuring safety while enhancing preventative effects. Furthermore, the drive component (i.e., the intelligent gradient adjustment module 104) is mounted on the outer surface, preserving the structure of the stockings and ensuring a comfortable fit without hindering daily activities.

[0097] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0098] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A lower limb intelligent pressure-adjustable elastic stocking with integrated ultrasound monitoring, comprising a medical elastic stocking body, characterized in that, Also includes: Multiple patch ultrasound transducer units are respectively installed in multiple internal fixation chambers of the medical elastic stocking and arranged sequentially from top to bottom along the anatomical sites of the main veins of the lower limbs. The acoustic window of each patch ultrasound transducer unit is attached to the skin through coupling gel for non-invasive quantitative acquisition of ultrasound echo signals of lower limb venous hemodynamics. The elastic stocking intelligent gradient adjustment module includes multiple flexible pressure adjustment units that are detachably connected to the outer surface of the medical elastic stocking. The multiple flexible pressure adjustment units are set one-to-one with the monitoring points of the multiple patch ultrasound transducer units. The elastic stocking intelligent gradient adjustment module is used to implement targeted and graded gradient pressure dynamic adjustment for lower extremity venous thrombosis. The signal processing and transmission unit is located in the external fixation chamber of the medical elastic stocking and is used to receive the ultrasonic echo signals collected by each patch ultrasonic transducer unit and the resistance signals transmitted by the elastic stocking intelligent gradient adjustment module. After processing and analysis, it generates and outputs control commands to the elastic stocking intelligent gradient adjustment module. The signal processing and transmission unit includes an algorithm storage module for determining the DVT risk level based on the ultrasonic echo signal and generating a pressure adjustment strategy, and a micro control chip module for executing the control commands and realizing closed-loop feedback calibration. The central monitoring and early warning unit is wirelessly connected to the signal processing and transmission unit to receive ultrasound monitoring data, elasticity adjustment data and DVT risk data, realize data management and retain manual intervention authority.

2. The intelligent pressure-adjustable elastic stockings for the lower limbs with integrated ultrasound monitoring according to claim 1, characterized in that, Each of the aforementioned flexible pressure regulating units includes: The shape memory polymer flexible annular strip is made of thermally responsive polycaprolactone and has a shrinkage rate of 15% to 20% and a glass transition temperature of 45 to 55°C. A miniature heating element is attached to the outer surface of the shape memory polymer flexible annular strip to transfer heat energy to the shape memory polymer flexible annular strip. A miniature temperature sensor is attached to the center of the shape memory polymer flexible annular strip using thermally conductive adhesive to collect temperature data of the shape memory polymer flexible annular strip in real time. A miniature tension strain gauge is embedded inside the shape memory polymer flexible annular strip to collect tension data of the shape memory polymer flexible annular strip in real time. The external fixation ring is made of medical-grade nylon Velcro, with the hook side sewn to the back of one end of the shape memory polymer flexible annular strip and the rough side sewn to the front of the other end of the shape memory polymer flexible annular strip. The micro heating element, micro temperature sensor, and micro tension strain gauge are all electrically connected to the signal processing and transmission unit.

3. The intelligent pressure-adjustable elastic stockings for the lower limbs with integrated ultrasound monitoring according to claim 2, characterized in that, Multiple flexible pressure adjustment units are respectively formed on the medical elastic stocking body in area A, area B, area C, area D, and area D, which are adapted to the middle section of the calf and correspond to the middle section of the posterior tibial vein, area B, area C, area C, area D, and area D, respectively, which are adapted to the middle and lower section of the thigh and correspond to the middle and lower section of the femoral vein. The flexible pressure adjustment units are detachably connected to the medical elastic stocking body through an external fixation ring.

4. The intelligent pressure-adjustable elastic stockings for the lower limbs with integrated ultrasound monitoring according to claim 2, characterized in that, The signal processing and transmission unit further includes: The outer casing has a switch and warning module on its outer surface and a main board circuit inside its cavity. The motherboard circuit integrates a multi-path selection module, an analog signal processing module, a beamforming module, an IQ module, an algorithm storage module, a micro control chip module, a wireless transmission module, a heat dissipation device, a battery, and a power converter. The multi-path selection module is used to receive the ultrasonic echo signal collected by the patch ultrasonic transducer unit and the resistance signal transmitted by the miniature temperature sensor and the miniature heating plate, and the multi-path selection module is used to alternately select the signals collected from multiple zones.

5. The intelligent pressure-adjustable elastic stockings for the lower limbs with integrated ultrasound monitoring according to claim 1, characterized in that, The central monitoring and early warning unit is one or more of a tablet computer, a monitor, a smartphone, and a cloud server. It is used to realize the full recording of ultrasonic monitoring data, elasticity adjustment records, risk level changes, remote monitoring, and historical trajectory query. The central monitoring and early warning unit also supports drive switching and manual adjustment of elasticity gradient.

6. A method for using the integrated ultrasound monitoring lower limb intelligent pressure-adjusting elastic stockings according to any one of claims 1-5, characterized in that, Includes the following steps: Step 0: The medical elastic stockings are worn on the user's lower limbs to fix the patch ultrasound transducer units, flexible pressure adjustment units, and signal processing and transmission units. Specifically, during wear, the four patch ultrasound transducer units are placed in the internal fixation chamber, and the acoustic windows are attached to the skin surfaces of the middle segments of the posterior tibial vein, popliteal vein, lower femoral vein, and common femoral vein of the user's lower limbs using coupling gel. A shape memory polymer flexible ring strip is attached to the patch ultrasound transducer units via an external fixation ring and is tightly fitted to the outer surface of the medical elastic stockings without affecting blood circulation in the lower limbs. The signal processing and transmission unit is placed in the external fixation chamber and connected to each patch ultrasound transducer unit and the flexible pressure adjustment unit. Step 1: Turn on each patch ultrasonic transducer unit, flexible pressure adjustment unit, and signal processing and transmission unit, and each performs automatic initialization operations; enter the user's basic information through the central monitoring and early warning unit; Step 2: The baseline blood flow indicators of the user's lower limb veins at rest are collected by four patch ultrasound transducer units. The signal processing and transmission unit is used to calibrate the individualized risk assessment threshold based on the pre-stored risk level-adjustment amplitude mapping algorithm according to the baseline blood flow indicators. The elastic stockings' intelligent gradient adjustment module maintains a basic elastic gradient in each zone, specifically: zone A 25mmHg, zone B 20mmHg, zone C 16.2mmHg, and zone D 10mmHg. Step 3: When the user sits or lies down for a long time, causing changes in the blood flow status of the lower limbs, the four patch ultrasound transducer units alternately collect the ultrasound echo signals of the lower limb venous hemodynamics at fixed time intervals, and transmit them to the signal processing and transmission unit for processing to obtain accurate ultrasound data. Step 4: The algorithm storage module determines the DVT risk level based on the calibrated risk level-adjustment amplitude mapping algorithm and the accurate ultrasound data. Based on the determined DVT risk level, the mapping algorithm is called to generate the corresponding graded pressure adjustment strategy, and the adjustment strategy is transmitted to the micro control chip module simultaneously. Step 5: The micro control chip module drives the corresponding flexible pressure regulating unit to perform targeted or global gradient pressurization according to the pressure regulation strategy. At the same time, it collects temperature and elasticity feedback signals in real time through micro temperature sensors and micro tension strain gauges to perform closed-loop calibration of the pressurization process to ensure pressurization accuracy. Step 6: The patch ultrasound transducer unit continuously collects lower limb venous hemodynamic data after pressurization. After being processed by the signal processing and transmission unit, the data is transmitted to the algorithm storage module. The algorithm storage module re-determines the DVT risk level based on the processed data. If the risk level drops back to level 0, the micro control chip module receives the feedback signal and outputs a pressure holding duration command to perform the pressure holding operation. If the risk level remains unchanged, the current adjustment strategy will be implemented with a slight adjustment of 2%. If the risk level increases, the pressure-intensifying strategy will be upgraded, and the early warning module will be triggered; If excessive pressure is detected, immediately perform an emergency pressure relief procedure; Step 7: Upload the data from Steps 2 to 6 in real time to the central monitoring and early warning unit via the wireless transmission module to achieve full data recording, remote monitoring and historical trajectory query. At the same time, the central monitoring and early warning unit retains manual intervention authority, which can switch driving modes and adjust elastic gradient.

7. The working method according to claim 6, characterized in that, In step four, the DVT risk level is divided into levels 0-3, and the judgment criteria are as follows: When the blood flow parameters in the ultrasound data are within the normal physiological range, the stasis index is <0.8, and there is no hypoechoic filling in the venous lumen, it is judged as grade 0; When a single parameter in the ultrasound data exceeds the individualized risk assessment threshold, specifically, a 20% decrease in blood flow velocity from baseline, a stasis index of 0.8–1.2, venous diameter dilation of <30%, and no hypoechoic filling in the venous lumen, it is assessed as Grade 1; When multiple parameters in the ultrasound data are abnormal, specifically, blood flow velocity decreases by more than 30%, stasis index is >1.2, venous diameter dilation is 30% ≤ 50%, and cloud-like fine echogenic spots appear in the venous lumen, it is judged as grade 2; When ultrasound data shows flocculent or clump-like hypoechoic areas in the venous lumen, sparse or absent blood flow signals, and significant dilation of the venous diameter ≥50%, it is classified as grade 3.

8. The working method according to claim 7, characterized in that, In step four, the graded pressure regulation strategy corresponding to the DVT risk level is as follows: When the DVT risk level is 0 and a single ultrasound parameter exceeds the threshold for 3 consecutive zones, the threshold instant adjustment mode is triggered, which starts a low-amplitude stepwise temperature increase only for the corresponding target zone, with an amplitude of 3 to 5°C per level and a 5-second pause after each temperature increase, to achieve small-amplitude pressure prevention. When the DVT risk level is Level 1, local targeted adjustment is triggered, with the corresponding zonal base gradient increased by 10% to 15%, the maximum increase in a single zonal gradient being 3 mmHg, and adjacent zonal gradients being increased by 5% simultaneously. When the DVT risk level is level 2, all zones are coordinated to adjust, the base gradient is increased by 20% to 25%, and the maximum increase in a single zone is 6 mmHg. When the DVT risk level is level 3, an emergency linkage adjustment is triggered, the basic gradient is increased by 30% but not exceeding the safety limit, and the early warning module and emergency data push are triggered simultaneously, and all target partitions are fully pressurized.

9. The working method according to claim 6, characterized in that, In step five, the pressure-driving body of the flexible pressure regulating unit is a shape memory polymer flexible annular strip, and the pressure regulation strategy pauses for 5 seconds after each stage of heating to perform closed-loop calibration. The closed-loop calibration process includes: The miniature temperature sensor collects the temperature of the shape memory polymer flexible annular strip in real time. After being processed by the signal processing and transmission unit, the temperature is fed back to the algorithm storage module and compared with the preset target temperature of 45-55℃. If the temperature is too high, the input voltage is reduced or the power supply is stopped; if the temperature is too low, the input voltage is increased. The micro tension strain gauge collects the contraction tension of the shape memory polymer flexible annular strip in real time. The signal processing and transmission unit converts it into the actual elastic force value and feeds it back to the algorithm storage module. It is compared with the preset target elastic force value. If the deviation exceeds ±1 mmHg, the next stage of temperature increase is finely adjusted by ±1℃ to calibrate the pressurization accuracy.

10. The working method according to claim 6, characterized in that, In step six, the criteria for determining the excessive compression state are as follows: when the pressure monitoring value of the micro tension strain gauge exceeds the medical level three DVT prevention pressure threshold, that is, ≤30mmHg in the calf and ≤15mmHg in the proximal thigh, or when ultrasound monitoring shows a sudden reduction in the venous diameter of >30%, it is determined to be an excessive compression state. In step six, the emergency pressure relief operation is as follows: the micro control chip module outputs a pressure relief and reset command, the temperature is increased by 2-3°C per stage and maintained for 8 seconds, driving the shape memory polymer flexible annular strip gradient to reset and fall back to the basic elastic gradient.

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