Double-cavity biliary tract drainage catheter with monitoring module and method thereof

Abstract

The invention discloses a double-cavity biliary tract drainage catheter with a monitoring module and a method of the double-cavity biliary tract drainage catheter, and belongs to the technical field of medical instruments.The method includes the steps that S1, an intelligent double-cavity biliary tract drainage system is provided and comprises a drainage catheter with an asymmetric double-cavity structure, the section of the drainage catheter is composed of a main drainage cavity and a monitoring sensing cavity, and the sectional area of the monitoring sensing cavity is smaller than that of the main drainage cavity. A miniature pressure sensor and an ultrasonic transduction piece are integrated on a tip ring part of the drainage catheter, and thermistor arrays are symmetrically arranged on the two sides of a side hole of the drainage catheter. Through the asymmetric double-cavity structural design, the flow resistance of high-viscosity bile is effectively reduced, and through cooperation with an anti-scaling coating wrapping the outer wall, the anti-scaling effect of the high-viscosity bile is improved. The risks of protein adsorption and bacterial colonization are reduced from the physical level, and the occurrence rate of retrograde cholangitis is remarkably reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a double-lumen biliary drainage catheter with a monitoring module and a method thereof. BACKGROUND

[0002] In the process of clinical biliary drainage treatment, the traditional single-lumen drainage catheter faces the problem of physical blockage of the pipeline when dealing with high-viscosity bile. Due to the lack of effective real-time monitoring means, it is difficult for medical staff to discover abnormalities in the first time when the catheter position drifts or the side hole is attached. This situation leads to the inability of managers and medical staff to quickly locate the root cause of the decline in drainage efficiency, and often only passive intervention is carried out after the drainage fluid completely stops dripping.

[0003] In addition, the traditional drainage method lacks the ability to predict the growth trend of the deposits in the lumen. In order to confirm the position of the catheter, it is usually necessary to rely on repeated X-ray imaging, which not only increases the harm of ionizing radiation to the patient, but also increases the burden of secondary examination. The above shortcomings are mainly due to the simplicity of the drainage device structure and the lack of sensing technology, resulting in that the spatial resolution and time response speed of data acquisition cannot meet the needs of precision medicine.

[0004] The above information disclosed in the background section is only used to enhance the understanding of the background of the present disclosure, and therefore it can include information that does not constitute the prior art known to those of ordinary skill in the art. SUMMARY

[0005] The purpose of the present application is to provide a double-lumen biliary drainage catheter with a monitoring module and a method thereof to solve the problems raised in the background.

[0006] The technical solution of the present application is: S1, providing an intelligent double-lumen biliary drainage system, the intelligent double-lumen biliary drainage system comprising a drainage catheter with an asymmetric double-lumen structure, wherein the cross section of the drainage catheter is composed of a main drainage lumen and a monitoring sensing lumen, and the cross-sectional area of the monitoring sensing lumen is smaller than that of the main drainage lumen; a micro pressure sensor and an ultrasonic transducer sheet are integrated at the tip ring of the drainage catheter, and a thermistor array is symmetrically arranged on both sides of the side hole of the drainage catheter; S2, performing pressure field monitoring, using the micro pressure sensor to obtain the hydrostatic pressure and dynamic flow pressure signals in the bile duct environment where the drainage catheter is located in real time, and predicting the patency state of the main drainage lumen by calculating the pressure fluctuation curve; S3, performing acoustic-thermal synergistic sensing, using the ultrasonic transducer to emit and receive acoustic wave echoes to monitor the thickness of the sediment on the inner wall of the main drainage lumen, and using the thermistor array to monitor the heat exchange data of the bile flowing through the side hole to determine the spatial pose and flow rate state of the drainage catheter; S4, performing adaptive self-cleaning maintenance, when the sediment thickness monitored by the ultrasonic transducer exceeds a preset threshold or the pressure fluctuation curve shows a risk of obstruction, injecting cleaning liquid into the monitoring sensing cavity to the tip ring part for pulse flushing.

[0007] Preferably, in the step S2, the analysis process of the pressure fluctuation curve includes: Before the drainage fluid volume changes, real-time extraction of the sampling data of the pressure monitoring module, calculation of the correlation between the pressure drop rate and the reduction of the pipe cross-sectional area, to identify the incomplete blockage state of the pipe.

[0008] Preferably, in the step S3, the process of determining the spatial pose using the thermistor array includes: Based on the principle of thermal dilution, the resistance value change of each resistor in the thermistor array is obtained; The asymmetry of the resistance value change is calculated by a differential bridge circuit, and when the asymmetry exceeds a preset deviation range, it is determined that the side hole of the drainage catheter is wall-adhered or displaced, and a displacement warning signal is issued.

[0009] Preferably, the step S4 further includes: A micro one-way valve is arranged at the end of the monitoring sensing cavity to prevent bile from entering the monitoring sensing cavity during drainage; When receiving a cleaning instruction, the micro one-way valve is opened by increasing the fluid pressure in the monitoring sensing cavity to realize directional jet flushing.

[0010] Preferably, the manufacturing process of the drainage catheter includes: The micro pressure sensor and the ultrasonic transducer are packaged to resist corrosion of bile salts, ensuring stable operation in a bile environment with a preset pH value.

[0011] A double-lumen biliary drainage catheter with a monitoring module, comprising: The drainage catheter has an asymmetric double-lumen structure, and its cross-section is divided into a main drainage lumen with a large D type and a monitoring sensing cavity with a small D type; The tip ring part is arranged at the distal end of the drainage catheter and internally integrated with a micro pressure sensor and an ultrasonic transducer; The sensing assembly includes a thermistor array arranged on both sides of the side hole; The self-cleaning module includes a miniature one-way valve located at the end of the monitoring and sensing cavity, and the miniature one-way valve is connected to an external flushing liquid source; The controller is electrically connected to the miniature pressure sensor, the ultrasonic transducer, the thermistor array, and the self-cleaning module, respectively.

[0012] Preferably, the cross-sectional area ratio of the main drainage cavity to the monitoring and sensing cavity is within a preset ratio range to ensure the integration of drainage and monitoring functions within a limited outer diameter of the catheter.

[0013] Preferably, a flexible microcircuit is embedded inside the monitoring sensing cavity, and the flexible microcircuit is used to connect the sensor of the tip ring to the controller.

[0014] Preferably, the drainage catheter is made of a biomedical material resistant to bile salt corrosion, and the outer wall of the drainage catheter is coated with an anti-scaling coating.

[0015] Preferably, the controller generates a pressure monitoring curve at a preset sampling frequency based on the data collected by the miniature pressure sensor, and performs a blockage risk level assessment in conjunction with the acoustic echo intensity of the ultrasonic transducer.

[0016] This invention provides an improved double-lumen biliary drainage catheter with a monitoring module and its method, which has the following improvements and advantages compared with the prior art: 1. Through the asymmetric dual-chamber structure design, the flow resistance of high-viscosity bile is effectively reduced. Combined with the anti-scaling coating on the outer wall, the risk of protein adsorption and bacterial colonization is reduced from a physical level, which significantly reduces the incidence of retrograde cholangitis. 2. The controller combines the pressure monitoring curve of the miniature pressure sensor with the acoustic echo intensity of the ultrasonic transducer to perform obstruction risk level assessment. The ultrasonic transducer can measure deposits up to 0.5 mm thick, and the increased echo signal intensity helps identify early signs of biliary sludge hardening. Strategies such as adjusting frequency, providing alerts, or automatically triggering pulsed flushing are adopted for different risk levels, thus optimizing the utilization of medical resources. 3. By using a thermistor array and differential bridge circuit, the system can determine the spatial orientation of the drainage catheter in real time. When it is determined that the side hole is attached to the wall, an early warning is issued, which allows medical staff to reset it through bedside color Doppler ultrasound, avoiding the ionizing radiation damage caused by repeated X-ray imaging in traditional methods. 4. The self-cleaning module uses the monitoring sensor cavity as an independent path. By increasing the fluid pressure, it opens the miniature one-way valve. Through multi-level encapsulation of the sensor, the system can work continuously and stably for more than 14 days in a simulated bile environment, with the sensor drift rate controlled within 2%, ensuring the accuracy of long-term monitoring. Attached Figure Description

[0017] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall external structure of the device; Figure 2 yes Figure 1 Enlarged view of the structure at point A in the middle; Figure 3 This is a schematic diagram showing the structural positions of the drainage catheter, side holes, ultrasonic transducer, thermistor array, and miniature one-way valve.

[0018] Figure 4 This is a schematic diagram of the cross-sectional structure of the drainage catheter; Figure 5 This is a schematic diagram of the process flow of the method of the present invention.

[0019] In the figure: 100, Intelligent dual-lumen biliary drainage system; 110, Drainage catheter; 111, Main drainage cavity; 112, Monitoring and sensing cavity; 113, Tip ring; 114, Side hole; 120, Miniature pressure sensor; 130, Ultrasonic transducer; 140, Thermistor array; 150, Miniature one-way valve; 160, Flexible microcircuit. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0021] Example 1, please refer to Figures 1-5 This invention provides a dual-lumen biliary drainage method with a monitoring module, comprising: S1. A smart dual-lumen biliary drainage system 100 is provided. The smart dual-lumen biliary drainage system 100 includes a drainage conduit 110 with an asymmetric dual-lumen structure. The cross-section of the drainage conduit 110 is composed of a main drainage cavity 111 and a monitoring and sensing cavity 112, and the cross-sectional area of ​​the monitoring and sensing cavity 112 is smaller than the cross-sectional area of ​​the main drainage cavity 111. A miniature pressure sensor 120 and an ultrasonic transducer 130 are integrated in the tip ring 113 of the drainage conduit 110, and a thermistor array 140 is symmetrically arranged on both sides of the side hole 114 of the drainage conduit 110. S2. Perform pressure field monitoring, use miniature pressure sensor 120 to obtain the hydrostatic pressure and dynamic flow pressure signals in the bile duct environment where the drainage tube 110 is located in real time, and predict the patency of the main drainage cavity 111 by calculating the pressure fluctuation curve. S3. Perform acoustic-thermal co-sensing, using the ultrasonic transducer 130 to emit and receive acoustic echoes to monitor the thickness of deposits on the inner wall of the main drainage cavity 111, and at the same time, use the thermistor array 140 to monitor the heat exchange data when bile flows through the side hole 114 to determine the spatial orientation and flow rate of the drainage tube 110. S4. Perform adaptive self-cleaning maintenance. When the thickness of the deposit monitored by the ultrasonic transducer 130 exceeds the preset threshold or the pressure fluctuation curve shows that there is a risk of blockage, the cleaning fluid is injected into the tip ring 113 in reverse through the monitoring sensing cavity 112 for pulse flushing.

[0022] In the implementation of the intelligent dual-lumen biliary drainage system 100, to address the technical problems of easy blockage of existing single-lumen drainage tubes when dealing with high-viscosity bile and the difficulty in detecting tube displacement, the drainage catheter 110 adopts a specific asymmetric dual-lumen structure. The design intent of this structure is to utilize the main drainage cavity 111 to ensure sufficient physical space for drainage, while using the monitoring and sensing cavity 112 as an independent functional channel. In terms of specific mechanical implementation, the main drainage cavity 111 has a large D-shaped cross-section, while the monitoring and sensing cavity 112 is designed as a small D-shape, with a cross-sectional area ratio of 4:1. This asymmetry allows the drainage catheter 110 to provide a sufficiently spacious main drainage cavity 111 to reduce flow resistance even with a limited outer diameter, while the monitoring and sensing cavity 112 provides an independent fluid path for subsequent cleaning fluid delivery.

[0023] The tip ring 113 of the drainage catheter 110 is shaped like a pig's tail. This mechanical design increases the catheter's anchoring force within the bile duct. The end of the tip ring 113 encapsulates a miniature pressure sensor 120 and an ultrasonic transducer 130 using medical-grade epoxy resin. The miniature pressure sensor 120 is a high-precision piezoresistive sensor (model MS5837-02BA) with excellent resistance to bile salt corrosion and can sense pressure changes as small as 0.1 mbar. The ultrasonic transducer 130 is made of PZT-5H piezoelectric ceramic material and operates at a frequency of 10 MHz. On both sides of the side hole 114, a thermistor array 140 consists of multiple NTC-10K thermistors arranged linearly at 2 mm intervals.

[0024] During pressure field monitoring, the miniature pressure sensor 120 converts the pressure within the bile duct into a weak electrical signal, which is then transmitted to the controller. The controller, which can be an STM32F405, samples the signal at 100Hz to obtain the hydrostatic pressure. When bile flows within the main drainage chamber 111, the miniature pressure sensor 120 captures the dynamic flow pressure signal due to fluid friction and viscosity. Increased bile viscosity leads to increased fluid resistance R. Based on the relationship between pressure gradient and flow rate, when the main drainage chamber 111 experiences incomplete blockage, the pressure fluctuation characteristics at the proximal and distal ends will change. The controller constructs a pressure fluctuation curve by calculating the standard deviation between sampling points. If the amplitude of the curve gradually decreases and the reference pressure increases, it is predicted that sediment accumulation exists in the main drainage chamber 111.

[0025] During acoustic-thermal co-sensing, the ultrasonic transducer 130 is excited to generate high-frequency sound waves. After passing through the bile, the sound waves are reflected off the inner wall of the main drainage cavity 111. Because the acoustic impedance of sludge or stones differs from that of bile, the reflected echo signal is offset on the time axis. The controller calculates the physical thickness of the deposit by measuring the time difference between the emitted sound wave and the received echo, combined with the sound velocity constant. Simultaneously, the thermistor array 140 is under controlled isothermal heating. When bile flows through the side holes 114, it carries away heat from the thermistor surface. The higher the flow rate, the faster the heat loss, and the more drastic the change in the thermistor resistance. By monitoring this heat exchange data, the real-time flow rate of the bile can be determined.

[0026] When the thickness of the deposits monitored by the ultrasound transducer 130 reaches a preset threshold of 0.5 mm, or when the slope of the pressure fluctuation curve exceeds the safe range, the drainage catheter 110 enters the self-cleaning maintenance phase. The controller controls an external power source, i.e., the self-cleaning module power source, such as a stepper motor-driven infusion pump, to deliver saline solution through the monitoring sensor cavity 112 to the tip ring 113. Since the monitoring sensor cavity 112 is independent, the cleaning solution does not mix with the drainage solution; instead, it flushes the entrance of the main drainage cavity 111 through pulsed high-pressure jets, thereby removing biliary sludge. Based on this combination of structure and method, the drainage catheter 110 achieves a shift from passive observation to active intervention, ensuring the continuity of the drainage process without increasing the burden of secondary examinations for the patient.

[0027] In step S2, the analysis process of the pressure fluctuation curve includes: Before the drainage fluid volume changes, the sampling data of the pressure monitoring module is extracted in real time, and the correlation between the pressure drop rate and the reduction in the cross-sectional area of ​​the pipeline is calculated to identify the incomplete blockage state of the pipeline.

[0028] The specific identification steps are as follows: The controller continuously acquires the dynamic flow pressure signal within 1 second through the ADC and stores it in the ring buffer; the sliding average algorithm is used to filter out pump pressure noise and extract the baseline pressure trend; the current trend slope is compared with the clean pipeline pressure feature map stored in memory in real time. If the slope deviation exceeds the preset envelope, it is determined to be incomplete blockage. In the detailed implementation of step S2, the analysis of the pressure fluctuation curve involves a process of fluid dynamics data conversion. The miniature pressure sensor 120 continuously outputs an analog voltage signal, which is converted into numerical pressure sampling data by a 12-bit analog-to-digital converter within the controller. During the initial phase of normal operation of the drainage tube 110, the controller records the rate of decrease in the baseline pressure. Because the biliary system is a relatively closed and somewhat flexible biological conduit, the discharge of bile creates a dynamic pressure gradient within the main drainage cavity 111.

[0029] When cellulose or sludge begins to deposit inside the main drainage chamber 111, the effective cross-sectional area of ​​the main drainage chamber 111 will decrease slightly. This decrease in cross-sectional area will lead to an increase in the local flow velocity of the fluid, thereby causing an increase in dynamic pressure. Before the macroscopic drainage volume decreases significantly and is visible to the naked eye, the pressure sampling data captured by the miniature pressure sensor 120 has already shown characteristic changes. The controller obtains the pressure change rate by performing a first derivative calculation on the pressure drop rate over 50 consecutive sampling cycles.

[0030] When calculating the correlation between the pressure drop rate and the reduction in pipe cross-sectional area, preset fluid model parameters were used. The fluid model, based on the Hagen-Poiseuille law, characterizes the quasi-linear relationship between the viscosity of the bile in the main drainage chamber 111111, the pipe diameter, and the pressure drop. It aims to inversely calculate the effective flow diameter of the chamber through pressure feedback. If the measured pressure drop rate is slower than 80% of the normal rate, it means that back pressure has been generated inside the main drainage chamber 111 due to the narrowing of the cross-sectional area. This correlation in the data reflects the incomplete blockage state inside the pipe. This identification method can issue an early warning signal 30 minutes before the main drainage chamber 111 is completely blocked, providing sufficient decision-making buffer for self-cleaning operations and avoiding the lag of traditional drainage tubes where problems are only detected when dripping has completely stopped. Based on real-time correction of the pressure fluctuation curve, the system can remain sensitive to minute physical changes.

[0031] In step S3, the process of determining the spatial pose using the thermistor array 140 includes: Based on the principle of thermal dilution, the resistance changes of each resistor in the thermistor array 140 are obtained. The asymmetry of resistance change is calculated by a differential bridge circuit. When the asymmetry exceeds the preset deviation range, it is determined that the side hole 114 of the drainage tube 110 has been attached to the wall or displaced, and a displacement warning signal is issued.

[0032] The process of determining spatial pose in step S3 fully utilizes the energy transfer difference between the bile environment inside the body and the duct surface. The thermistor array 140 is symmetrically arranged along the side hole 114 of the drainage duct 110. Based on the principle of thermal dilution, the controller provides a constant microcurrent to the thermistor array 140, making its temperature slightly higher than the ambient bile temperature by about 0.5 degrees Celsius. When the bile flows uniformly in the bile duct, the thermistors on both sides of the side hole 114 will be subjected to a relatively uniform fluid cooling effect.

[0033] The resistance change of each thermistor represents the local cooling rate. When the drainage tube 110 is in the center of the bile duct, the fluid flow is symmetrical, and the potential difference output of the two arms of the differential bridge circuit is close to zero. The differential bridge circuit can be constructed by a high-performance operational amplifier AD8628. If the drainage tube 110 is displaced due to respiratory movement or changes in the patient's position, causing one side of the side hole 114 to approach the bile duct wall, the thermistor on that side will be wrapped by the duct wall tissue, causing the fluid cooling effect to disappear, and the temperature at that location will rise rapidly.

[0034] This temperature rise directly causes asymmetry in resistance changes. The controller monitors the voltage output of the differential bridge circuit in real time. When this asymmetry exceeds a preset deviation range of 15%, the controller determines that the side hole 114 has severely adhered to the wall. This 15% deviation range is based on the ratio of the zero bias voltage in the balanced state of the differential bridge to the actual output voltage, used to quantify the unevenness of circumferential heat dissipation. This threshold is a key boundary for distinguishing between flow rate fluctuations caused by normal breathing and physical adhesion to the wall. In this state, even if the tubing itself is not blocked, bile cannot smoothly enter the side hole 114, resulting in decreased drainage efficiency. By issuing a displacement warning signal, medical staff can accurately reposition the patient using bedside ultrasound, solving the problem of blindly relying on repeated X-ray angiography for confirmation in traditional drainage, which makes real-time displacement monitoring difficult and reduces the risk of ionizing radiation damage to patients.

[0035] The steps preceding S4 also include: A miniature one-way valve 150 installed at the end of the monitoring sensing cavity 112 is used to prevent bile from entering the monitoring sensing cavity 112 during the drainage process. When a cleaning command is received, the miniature check valve 150 is opened by increasing the fluid pressure in the monitoring sensing cavity 112 to achieve directional jet flushing.

[0036] Before performing self-cleaning maintenance, ensuring the physical isolation of the monitoring sensing cavity 112 is crucial for stable sensor operation. The miniature one-way valve 150, a duckbill-shaped structure made of medical-grade fluororubber, is installed at the junction of the monitoring sensing cavity 112 and the tip ring 113. During normal drainage, the pressure inside the bile duct is between 10 and 20 cm of water column, which is insufficient to overcome the back-sealing force of the miniature one-way valve 150. Therefore, corrosive bile is effectively isolated from the monitoring sensing cavity 112, preventing chemical erosion of the internal flexible circuitry and avoiding impurity deposition within the sensing cavity.

[0037] When the controller determines that rinsing is required and issues a cleaning command, the external pressure mechanism starts working. This pressure mechanism is a small linear electric actuator with a thrust of up to 50 Newtons, which pushes the piston of a sterile syringe to inject pressurized heparin sodium saline solution into the monitoring sensing chamber 112. As the fluid pressure in the monitoring sensing chamber 112 rises to over 100 kPa, the duckbill opening of the miniature one-way valve 150 is deformed by pressure and opens.

[0038] At this point, the cleaning fluid is jetted at a high velocity towards the outlet of the tip ring 113. Because the outlet direction of the miniature one-way valve 150 is aligned with the inlet of the main drainage chamber 111, a directional jet is formed. This high-energy fluid generates sufficient shear force to peel away and flush away the early deposits adhering to the wall of the main drainage chamber 111 into the external drainage bag. This mechanical action transforms passive maintenance of the drainage tube into active prevention, eliminating the need for catheter removal and replacement, significantly reducing the risk of secondary interventional procedures due to infection or blockage during the catheterization period.

[0039] The manufacturing process of the drainage catheter 110 includes: The miniature pressure sensor 120 and the ultrasonic transducer 130 are encapsulated to resist bile salt corrosion, ensuring stable operation in a bile environment with a preset pH value.

[0040] In the manufacturing process of the drainage catheter 110, the lifespan of the sensor component determines the reliability of the entire drainage system. Since bile typically has a pH between 7.4 and 8.5 and contains a large amount of bile salts and organic components, these components are highly corrosive to exposed electronic components. During the encapsulation process, a 2-micron-thickness parylene vapor-deposited layer is coated onto the surface of the sensing diaphragm of the miniature pressure sensor 120. This material has excellent biocompatibility and water-resistant properties.

[0041] The ultrasonic transducer 130 is embedded in a specially made 316L stainless steel miniature shell. The opening of the shell uses an ultra-thin titanium alloy film welded by laser. This metal film can not only ensure the effective transmission of sound waves, but also act as a physical barrier to completely isolate bile. When assembling the tip ring 113, all electrical connection points are filled with high-temperature resistant bio-silicone. Through this multi-level encapsulation, the intelligent dual-chamber biliary drainage system 100 can work continuously and stably for more than 14 days in a simulated bile environment. Its sensor drift rate is controlled within 2% of the full scale, ensuring the long-term accuracy and effectiveness of the monitoring data.

[0042] Example 2, please refer to Figures 1-5 A dual-lumen biliary drainage catheter 110 with a monitoring module includes: The drainage catheter 110 has an asymmetric double-lumen structure, and its cross-section is divided into a large D-shaped main drainage cavity 111 and a small D-shaped monitoring and sensing cavity 112. The tip ring 113 is located at the distal end of the drainage conduit 110 and integrates a miniature pressure sensor 120 and an ultrasonic transducer 130. The sensing component includes a thermistor array 140 arranged on both sides of the side hole 114; The self-cleaning module includes a miniature one-way valve 150 located at the end of the monitoring and sensing cavity 112, which is connected to an external flushing liquid source. The controller is electrically connected to the miniature pressure sensor 120, the ultrasonic transducer 130, the thermistor array 140, and the self-cleaning module, respectively.

[0043] The intelligent dual-lumen biliary drainage device is the physical carrier for realizing the aforementioned collaborative sensing method. The drainage catheter 110 is made of polyurethane material through extrusion molding. The asymmetric dual-lumen structure gives the catheter different mechanical support characteristics. The large D-shaped main drainage lumen 111 occupies 75% of the total cross-sectional area of ​​the lumen, ensuring that the internal flow resistance is at a low level when draining highly viscous bile, and preventing spontaneous stasis caused by lumen narrowing.

[0044] The internal space of the tip ring 113 is precisely allocated, and the miniature pressure sensor 120 is placed on the outermost side of the ring to directly contact the fluid environment within the bile duct. The ultrasonic transducer 130 is mounted perpendicular to the axis of the main drainage cavity 111, and its emitted ultrasonic beam can cover the cross-section of the main drainage cavity 111. This geometric layout ensures that the sound waves generate the strongest echo signal when they encounter deposits on the tube wall. The thermistor array 140 in the sensing component is attached to the edge of the side hole 114 using flexible printed circuit technology.

[0045] The self-cleaning module, as an independent mechanical unit, connects to the external flushing fluid source via the internal cavity of the monitoring sensing chamber 112. The presence of a miniature one-way valve 150 acts as a mechanical safety feature, opening only when the pulse pressure output by the self-cleaning module exceeds 80 kPa. The controller, acting as the brain of the entire device, is housed in a control box near the proximal end of the catheter. The microprocessor within the controller coordinates the operation of various sensing elements. For example, when the pressure sensor detects a decrease in pressure pulsation, the controller automatically increases the sampling frequency of the ultrasonic transducer 130 to confirm the presence of any deposits. This coordinated operation among components transforms the intelligent dual-lumen biliary drainage device from a static plastic tube into a self-diagnostic and self-repairing medical system, significantly improving the safety of interventional treatment.

[0046] The cross-sectional area ratio of the main drainage cavity 111 to the monitoring and sensing cavity 112 is within a preset ratio range to ensure that the integration of drainage and monitoring functions is achieved within a limited outer diameter of the catheter.

[0047] To meet the stringent limitations on catheter outer diameter for percutaneous liver puncture in clinical practice, the outer diameter typically needs to be controlled between 8.5 and 10 Frenchies. In the design of the ratio between the main drainage cavity 111 and the monitoring sensor cavity 112, the cross-sectional area ratio is strictly set within a preset range of 3:1 to 5:1. If the main drainage cavity 111 is too large, the monitoring sensor cavity 112 will become too narrow, causing an exponential increase in fluid transmission resistance, resulting in the pumping pressure required by the self-cleaning module exceeding the structural strength limit of the catheter wall.

[0048] Conversely, if the monitoring sensing cavity 112 is too large, it will significantly weaken the drainage efficiency, making the main drainage cavity 111 prone to physical embedding when facing flocculent material. Through this precise cross-sectional area ratio design, the intelligent dual-cavity biliary drainage device achieves a balance between efficient drainage and high-pressure self-cleaning function while maintaining a slim outer diameter. The asymmetric D-shaped structure of the main drainage cavity 111 has better support under pressure and is less prone to lumen collapse, which provides structural protection for long-term tube placement.

[0049] The monitoring sensing cavity 112 has a flexible microcircuit 160 embedded inside, which is used to connect the sensor and controller of the tip ring 113.

[0050] Achieving electrical connections within the confined space of the drainage conduit 110 is a challenge. A flexible microcircuit 160 is embedded inside the monitoring sensing cavity 112 via a co-extrusion process. This flexible microcircuit 160 uses polyimide as its substrate and is covered with copper foil wires with a thickness of 1 mil. To prevent the wires from breaking during conduit bending, the flexible microcircuit 160 is designed with a spiral or wavy structure, providing a certain longitudinal tensile allowance.

[0051] One end of the flexible microcircuit 160 is connected to the pads of the miniature pressure sensor 120 and the ultrasonic transducer 130 within the tip ring 113 via micro-spot welding, while the other end passes through the tube wall and connects to the controller at the proximal end. This embedded design avoids direct exposure of wires to the drainage fluid or sensing cavity fluid, not only reducing the overall size of the device but also greatly enhancing the anti-interference capability of signal transmission. The flexible microcircuit 160 has extremely low distributed capacitance, ensuring that the high-frequency excitation signal of the ultrasonic transducer 130 does not undergo severe waveform distortion during transmission.

[0052] The drainage catheter 110 is made of a biomedical material that is resistant to bile salt corrosion, and the outer wall of the drainage catheter 110 is covered with an anti-scaling coating.

[0053] The drainage catheter 110 is made of medical-grade thermoplastic polyurethane as its main material, which has moderate hardness and excellent fatigue resistance in a physiological environment of 37 degrees Celsius. Since minerals in bile can easily form scale on the surface of the catheter, the outer wall of the drainage catheter 110 and the inner wall of the main drainage cavity 111 are both coated with a 10-micron-thick anti-scaling coating.

[0054] This anti-scaling coating, composed of a hydrophilic hydrogel and polytetrafluoroethylene nanoparticles, significantly reduces the adsorption of proteins on the surface. This material optimization, combined with an acoustic-pressure-thermal synergistic sensing system, forms a dual protection mechanism. The anti-scaling coating physically slows down fouling, while the monitoring system identifies residual deposits and guides cleaning based on data. Based on this material combination, the intelligent dual-lumen biliary drainage device can maintain surface smoothness for a longer period within the complex bile duct, reducing the risk of bacterial colonization caused by scaling on the catheter surface, thereby lowering the incidence of retrograde cholangitis.

[0055] The controller generates a pressure monitoring curve based on the data collected by the miniature pressure sensor 120 at a preset sampling frequency, and performs a blockage risk level assessment in conjunction with the acoustic echo intensity of the ultrasonic transducer 130.

[0056] As the information processing center of the intelligent dual-lumen biliary drainage device, the controller's algorithm hinges on a multi-source data fusion strategy. Real-time data provided by the miniature pressure sensor 120 is converted into a pressure monitoring curve by the controller at a preset sampling frequency of 100 Hz. A simple logic decision program runs internally within the controller, calculating the dynamic mean of the curve in real time.

[0057] When the pressure monitoring curve shows a continuous rise in the baseline pressure, and the echo signal captured by the ultrasonic transducer 130 increases in intensity by 10 dB at a specific depth, the controller determines that there is a high-risk obstruction. An increase in the intensity of the acoustic echo indicates an increase in the hardness or thickness of the reflecting material, which is often a precursor to biliary sludge hardening. By combining the macroscopic trend of the pressure monitoring curve with the microscopic evidence of the acoustic echo intensity, the controller can classify the obstruction risk into three levels: mild, moderate, and severe.

[0058] This grading system provides a precise stratification strategy for clinical intervention. For mild risk, the controller adjusts the monitoring frequency only via the thermistor array 140; for moderate risk, it alerts healthcare workers to monitor the drainage fluid characteristics; and for severe risk, it automatically triggers the self-cleaning module for pulsed flushing. Based on this precise data assessment, the intelligent dual-lumen biliary drainage device optimizes the use of medical resources, preventing excessive flushing from irritating the bile duct mucosa and ensuring timely unblocking of the tubing in critical moments, thus improving the reliability of drainage treatment for critically ill patients.

[0059] The overall operation of the drainage catheter 110 embodies the close integration of mechanical structure and electronic algorithm. The main drainage cavity 111 is responsible for basic bile drainage, while the flexible microcircuit 160 inside the monitoring and sensing cavity 112 ensures real-time information feedback. The tip ring 113 is monitored by pressure, temperature, and acoustic fields within the bile duct. Any minute physical displacement or deposit accumulation will be converted into an electrical signal by the sensor and fed back to the controller.

[0060] The controller performs slope analysis on the pressure monitoring curve generated by the miniature pressure sensor 120, enabling it to detect changes in bile viscosity. The underlying logic is that the fluid loses kinetic energy within a narrowing cross-sectional area. To eliminate this potential problem, the controller drives the power mechanism in the self-cleaning module to generate pulse thrust. The miniature check valve 150 opens under pressure, causing the cleaning fluid to be sprayed towards the blocked area of ​​the side port 114.

[0061] Meanwhile, the thermistor array 140, based on the principle of thermal dilution, uses a differential bridge circuit to identify whether the catheter has shifted against the bile duct wall. Because the thermal conductivity of human tissue differs from that of bile, changes in the thermistor's resistance can sensitively detect changes in the contact interface. Increased asymmetry means the catheter is no longer at the geometric center of the bile duct. This multi-parameter collaborative operation enables the intelligent dual-lumen biliary drainage system 100 to provide operational stability far exceeding that of traditional drainage tubes.

[0062] In summary, this invention constructs a three-dimensional sensing network through the asymmetric dual-lumen structure design of the drainage catheter 110, combined with an integrated miniature pressure sensor 120, an ultrasonic transducer 130, and a thermistor array 140. This network can not only monitor the patency of drainage macroscopically, but also measure the growth of deposits and the spatial orientation of the catheter within the bile duct microscopically. Based on the controller's logical processing of multi-source data, the system achieves a leap from a single drainage function to a comprehensive drainage platform with intelligent monitoring, early warning, and proactive maintenance capabilities. It effectively solves core clinical pain points such as high-viscosity bile blockage, catheter displacement, and monitoring deficiencies, demonstrating significant clinical application value and technological advantages.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dual lumen biliary drainage method with a band monitoring module, characterized in that, Comprise: S1. Provide an intelligent double-lumen biliary drainage system (100), which comprises a drainage catheter (110) with an asymmetric double-lumen structure, wherein the cross section of the drainage catheter (110) is composed of a main drainage lumen (111) and a monitoring sensor lumen (112), and the cross-sectional area of the monitoring sensor lumen (112) is smaller than that of the main drainage lumen (111); a micro pressure sensor (120) and an ultrasonic transducer sheet (130) are integrated in the tip ring (113) of the drainage catheter (110), and a thermistor array (140) is symmetrically arranged on both sides of the side hole (114) of the drainage catheter (110); S2. Perform pressure field monitoring, use the micro pressure sensor (120) to obtain the hydrostatic pressure and dynamic flow pressure signals in the bile duct environment where the drainage catheter (110) is located in real time, and predict the pipeline patency state of the main drainage lumen (111) by calculating the pressure fluctuation curve; S3. Perform acoustic-thermal collaborative sensing, use the ultrasonic transducer sheet (130) to emit and receive acoustic echoes to monitor the thickness of the sediment on the inner wall of the main drainage lumen (111), and at the same time monitor the heat exchange data of the bile flowing through the side hole (114) through the thermistor array (140) to determine the spatial pose and flow rate state of the drainage catheter (110); S4. Perform adaptive self-cleaning maintenance, when the sediment thickness monitored by the ultrasonic transducer sheet (130) exceeds the preset threshold or the pressure fluctuation curve shows that there is a risk of obstruction, reverse injection of cleaning fluid to the tip ring (113) through the monitoring sensor lumen (112) is performed for pulse flushing.

2. The double-pigtail biliary drainage method with a monitoring module according to claim 1, characterized in that, In the step S2, the analysis process of the pressure fluctuation curve includes: Before the drainage fluid volume changes, the sampling data of the pressure monitoring module is extracted in real time, the correlation between the pressure drop rate and the reduction amount of the pipeline cross-sectional area is calculated to identify the incomplete blockage state of the pipeline.

3. The dual lumen biliary drainage method with a monitoring module according to claim 1, wherein, In the step S3, the process of determining the spatial pose by using the thermistor array (140) includes: Based on the principle of thermal dilution, the resistance value change of each resistor in the thermistor array (140) is obtained; Through the differential bridge circuit, the asymmetry of the resistance value change is calculated, and when the asymmetry exceeds the preset deviation range, it is determined that the side hole (114) of the drainage catheter (110) is adhered or displaced, and a displacement warning signal is sent.

4. The dual lumen biliary drainage method with a monitoring module according to claim 1, wherein, Before the step S4, it further includes: A micro one-way valve (150) is arranged at the end of the monitoring sensor lumen (112) to isolate the bile in the drainage process from entering the inside of the monitoring sensor lumen (112); When receiving the cleaning instruction, the micro one-way valve (150) is opened by increasing the fluid pressure in the monitoring sensor lumen (112) to realize directional jet flushing.

5. The dual lumen biliary drainage method with a monitoring module according to claim 1, wherein, The manufacturing process of the drainage catheter (110) includes: The micro pressure sensor (120) and the ultrasonic transducer sheet (130) are packaged to resist corrosion of bile salts, ensuring stable operation in a bile environment with a preset pH value.

6. A double-lumen biliary drainage catheter (110) with a monitoring module for use in a double-lumen biliary drainage method with a monitoring module according to any one of claims 1 to 5, characterized in that Comprise: A drainage catheter (110) with an asymmetric double-lumen structure, which is divided into a large D-shaped main drainage lumen (111) and a small D-shaped monitoring sensor lumen (112) in cross section; A tip ring (113) is arranged at the distal end of the drainage catheter (110), and a micro pressure sensor (120) and an ultrasonic transducer sheet (130) are integrated inside; A sensing assembly includes an array of thermistors (140) arranged on both sides of the side hole (114); A self-cleaning module includes a micro one-way valve (150) arranged at the end of the monitoring sensor lumen (112), which is in communication with an external flushing liquid source; A controller is electrically connected to the micro pressure sensor (120), the ultrasonic transducer sheet (130), the array of thermistors (140), and the self-cleaning module, respectively.

7. A double lumen biliary drainage catheter (110) with a monitoring module according to claim 6, characterized in that The cross-sectional area ratio of the main drainage lumen (111) to the monitoring sensor lumen (112) is within a preset range to ensure the integration of drainage and monitoring functions under a limited catheter outer diameter.

8. A double lumen biliary drainage catheter (110) with a monitoring module according to claim 6, characterized in that, The monitoring sensor lumen (112) is embedded with a flexible microcircuit (160) inside, which is used to connect the sensors of the tip ring (113) to the controller.

9. A double lumen biliary drainage catheter (110) with a monitoring module according to claim 6, characterized in that, The material of the drainage catheter (110) is a biocompatible material resistant to bile salt corrosion, and the outer wall of the drainage catheter (110) is wrapped with an anti-fouling coating.

10. A double lumen biliary drainage catheter (110) with a monitoring module according to claim 6, characterized in that, The controller generates a pressure monitoring curve at a preset sampling frequency based on the data collected by the micro pressure sensor (120), and performs a blockage risk level assessment in combination with the sound wave echo intensity of the ultrasonic transducer sheet (130).

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