Non-water-seal portable thoracic cavity suction equipment

Abstract

The invention provides non-water-seal portable thoracic cavity suction equipment which comprises a suction apparatus and a matched drainage bottle and aims to solve the problems that a traditional water-seal bottle is low in pressure control precision and fuzzy in monitoring. A mirror image PCB, a liquid level electrode and a spiral coil are arranged in the drainage bottle; the aspirator integrates an electromagnetic negative pressure pump, a pressure storage tank, an air capacitor, a linear stepping flow valve and a micro-control unit. The hemoglobin concentration of drainage liquid is detected through magnetic coupling dual modes, a flow valve is controlled through a fuzzy PID algorithm to achieve negative pressure closed-loop adjustment, and quantitative and periodic emptying is achieved in combination with a positive pressure pump. By means of the technical scheme, precise digital adjustment of thoracic cavity negative pressure and real-time objective monitoring of postoperative bleeding can be achieved, and the safety and portability of clinical nursing are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a non-water-sealed portable chest suction device. Background Technology

[0002] Closed thoracic drainage, a core cornerstone of cardiothoracic surgery, is not only a direct physical means of draining abnormal air, blood, and exudate from the pleural cavity, but also a crucial life support pathway for restoring physiological negative pressure in the pleural cavity, promoting the re-expansion of collapsed lung tissue, and maintaining respiratory and circulatory stability. In clinical practice, the effectiveness of thoracic drainage directly affects whether patients can successfully navigate the acute phase postoperatively. Through continuous monitoring of drainage flow, characteristics, and gas leakage, clinicians can promptly identify life-threatening complications such as bronchopleural fistula and active bleeding.

[0003] In the long-term clinical evolution, such as Figure 1 As shown, existing drainage techniques primarily rely on the classic "water seal" principle, which utilizes a specific depth of sterile liquid to form a physical one-way valve, ensuring that the media within the pleural cavity are discharged in the forward direction under the respiratory pressure gradient, while simultaneously preventing atmospheric backflow. The traditional three-bottle system (collection bottle, water seal bottle, and pressure regulating bottle) and its integrated commercial devices are designed to achieve negative pressure regulation using gravity and the height of the water column. Specifically, the immersion depth of the ventilation tube within the pressure regulating bottle determines the upper limit of the suction negative pressure. This mechanical balancing mechanism has the advantages of being intuitive and cost-effective in maintaining basic drainage. However, with the deepening of modern precision medicine concepts and the higher requirements of Enhanced Recovery After Surgery (ERAS) for postoperative management, the inherent defects of this traditional drainage scheme based on physical media have gradually become apparent, evolving into multiple irreconcilable technical contradictions.

[0004] One of the core contradictions lies in the conflict between "physical coupling" and "patient mobility." The water-seal system, in principle, requires the drainage device to remain strictly vertical and always positioned below the patient's chest cavity level. Any accidental tilting or elevation could cause fluid to flow back into the chest cavity, inducing serious iatrogenic infection or tension pneumothorax. This technical characteristic fundamentally restricts postoperative patient activity, forcing them to remain bedridden for extended periods. This not only increases the probability of complications such as deep vein thrombosis in the lower extremities and atelectasis, but also contradicts the early ambulation advocated by modern rehabilitation medicine.

[0005] A deeper technical contradiction lies in the mismatch between "static regulation" and "dynamic physiological conditions." The pressure regulation mechanism of traditional water-seal bottles is a passive open-loop regulation. When a patient coughs or takes a deep breath, the intrathoracic pressure experiences sudden and dramatic positive and negative fluctuations (e.g., a positive pressure exceeding +38.4 cmH2O can be reached instantaneously during coughing). The inertia of the liquid in the pressure-regulating bottle and the lag in bubble formation prevent the system from responding to these sudden pressure changes in real time, resulting in extremely poor intrathoracic pressure stability. Furthermore, the natural evaporation of the pressure-regulating liquid during continuous suction causes a drop in the liquid level, resulting in unintentional negative pressure drift. This "hidden loss of control" not only reduces drainage efficiency but also poses a potential threat to the precise lung recruitment process.

[0006] In terms of data monitoring, existing technologies exhibit significant "subjectivity" and "lag." Clinically, assessing the degree of air leakage and the characteristics of drainage fluid still heavily relies on healthcare workers manually counting the frequency of air bubbles in the water-seal bottle and visually reading the scale on the collection bottle. This experience-based, extensive monitoring suffers from significant individual observational differences, failing to establish a continuous and objective digital trend. Especially when monitoring active bleeding within 24 hours post-surgery, traditional equipment lacks the ability to non-contact, real-time monitor the internal components of the drainage fluid (such as hemoglobin concentration), often only passively detecting the problem after significant accumulation of drainage volume. This feedback delay can easily jeopardize emergency treatment. Furthermore, the continuous noise from bursting air bubbles generated during suctioning significantly negatively impacts the patient's postoperative sleep quality and psychological state.

[0007] Correspondingly, although some digital drainage devices have emerged in the market in recent years, they often have technical shortcomings in maintaining airtightness under complex working conditions, handling viscous drainage fluid adhering to the walls, and accurately monitoring specific bleeding concentrations in a closed-loop manner. Fundamentally, how to construct a digital drainage system that can achieve precise negative pressure servo control, provide high-precision, non-contact real-time monitoring of drainage components, and is highly portable, while eliminating unstable water-sealing media, has become a major technical challenge and a bottleneck problem urgently needing to be solved in the field of cardiothoracic surgery equipment. Summary of the Invention

[0008] The purpose of this invention is to propose a non-water-sealed portable chest suction device to solve the technical problems of existing water-sealed chest drainage bottles, such as limited patient movement, lack of pressure regulation accuracy, unclear real-time monitoring data, severe noise interference, and risk of fluid backflow, which are caused by reliance on liquid sealing media.

[0009] To achieve the above objectives, the present invention proposes a non-water-sealed portable chest suction device, including a suction device and a disposable monitoring drainage bottle detachably connected to the suction device; The drainage bottle contains two mirror-symmetrically arranged PCB boards; On the opposite surfaces of the two PCB boards, symmetrical upper liquid level electrodes are installed on the upper part, and symmetrical lower liquid level electrodes are installed on the lower part. Symmetrical high-frequency coupling coils are etched on the middle and lower parts, forming a magnetic coupling resonance system. The suction device is connected to the reservoir of the drainage bottle via a rigid tube through an air passage, and a positive pressure pump and a negative pressure pump are used to provide a positive or negative pressure environment inside the drainage bottle.

[0010] Furthermore, the drainage bottle includes an upper cap, a lower cap, and a liquid reservoir; The top cover is a sealing cover plate on the upper end of the liquid storage cylinder. The middle part of the top cover is the input pipe. The input end of the input pipe is connected to the chest drainage tube connector through the input end hose. The input end hose is connected to the corresponding input clamp valve. The lower cover is a sealing cover for the lower end of the liquid storage cylinder. The middle part of the lower cover is the output pipe. The output end of the output pipe is connected to the output connector of the drainage bottle through the output end hose. The output end hose is connected to the corresponding output clamp valve. The side wall of the liquid storage cylinder is provided with a gas connection port for connecting a gas connection rigid pipe.

[0011] Furthermore, the liquid storage cylinder has two pre-installed PCB slots for inserting PCB boards.

[0012] Furthermore, the PCB board has four conductive pads at its ends, which are respectively connected to the two ends of the coil, the upper liquid level electrode, and the lower liquid level electrode. The surface of the top cover is provided with two sets of electrodes, four in each set, and the eight electrodes are electrically connected to eight conductive disks.

[0013] Furthermore, the surface of the PCB board is coated with a transparent waterproof polyurethane coating.

[0014] Furthermore, the aspirator includes a drainage bottle compartment for holding the drainage bottle, and the drainage bottle is equipped with an inlet clamp valve, an outlet clamp valve, and an electrode holder; the electrode holder is electrically connected to the electrodes on the top cover.

[0015] Furthermore, the suction device also includes a small-flow positive pressure pump, a gas container, a negative pressure storage tank, and an electromagnetic negative pressure pump; A two-way solenoid valve is installed on the gas connection rigid pipe, and it is connected to a small flow positive pressure pump; one end of the gas connection rigid pipe is connected to a gas container, and a micro negative pressure sensor is installed inside the gas container; the gas container is connected to a negative pressure storage tank through a small flow linear step flow valve and a large flow linear step flow valve respectively; the negative pressure storage tank is connected to an electromagnetic negative pressure pump, and a low negative pressure sensor is installed inside the negative pressure storage tank.

[0016] Furthermore, the attractor also includes a central processing unit and a display input control module.

[0017] Furthermore, the magnetically coupled resonance system executes the following monitoring logic: S1: Reference Measurement: The system acquires the air reference resonant frequency during the initialization phase. and air quality benchmark factor ; S2: Real-time sampling: When the drainage fluid touches the upper liquid level electrode, the system collects the current measured resonant frequency. Compared with the measured quality factor S3, Dual-mode concentration calculation: Frequency mode concentration calculation: ,in This is the frequency sensitivity coefficient. The frequency offset of pleural effusion relative to air; Q-value modulus concentration calculation: based on measured quality factor. relative to air reference quality factor The reciprocal increment is used to calculate the Q-value modulus concentration. S4. Consistency check: Calculate the concentration difference between the two models. ,like If it is less than the preset threshold, then As the final hemoglobin concentration output; S5, State determination: compare the measured resonant frequency f_{meas}fmeas with multiple preset frequency boundaries, if Frequency below alarm threshold If so, it is determined that postoperative active bleeding has occurred and an alarm is triggered.

[0018] Compared with the prior art, the advantages of the present invention are: 1. Highly portable and location-insensitive: This invention eliminates the physical risks of liquid backflow and seal failure through a non-water-seal dry design. The device can be moved with the patient, suspended on the bed, or even placed at an angle, no longer subject to the strict limitations of traditional water-seal bottles that must be placed below the chest cavity and vertically, greatly facilitating early postoperative ambulation.

[0019] 2. High-precision servo pressure control and stability: Utilizing a negative pressure storage tank as a physical isolation layer against mechanical vibration and airflow pulsation, combined with a micro-stepping linear flow valve and fuzzy PID control algorithm, quasi-static and highly stable regulation of intrathoracic negative pressure is achieved. The pressure control accuracy is significantly better than traditional pressure-regulating water-seal bottles, effectively addressing the drastic instantaneous pressure changes caused by patient coughing and breathing.

[0020] 3. Objective and accurate real-time bleeding monitoring: Utilizing magnetic induction detection technology based on dual-mode coupling of LC resonant frequency shift and Q-value change, non-contact real-time monitoring of hemoglobin concentration in drainage fluid is achieved. Compared to traditional manual visual observation of color, this invention provides quantitative data support (g / dL), enabling earlier detection of active bleeding and providing a three-level warning system, thus gaining valuable time for clinical decision-making.

[0021] 4. Digitalized Drainage Volume and Quantitative Analysis of Air Leakage: An automatic emptying and counting mechanism with a cycle of 100ml enables precise digital accumulation of drainage volume. Simultaneously, by analyzing the operating parameters of the linear flow valve, an indirect quantitative assessment of the degree of lung leakage is achieved, replacing the traditional subjective judgment method of "bubble grading," making the determination of extubation indications more scientific and objective.

[0022] 5. Quiet Operation and Anti-Fouling Design: By eliminating the physical mechanism of continuous bubbling from the pressure regulating bottle, the equipment operates with extremely low noise, significantly improving the ward environment. The positive pressure pulse venting design and 45° angled cap structure effectively solve the problem of drainage fluid sticking and solidifying on the sensor PCB surface, ensuring long-term detection accuracy.

[0023] 6. Full-process airtight safety protection: The physical shut-off design of the double-pinch valve ensures the airtightness and pressure safety of the pleural cavity in the event of liquid drainage and emergency, preventing pneumothorax caused by equipment malfunction or misoperation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a traditional three-bottle system. Figure 2 This is a schematic diagram of the overall structure of the drainage bottle in an embodiment of the present invention; Figure 3 This is a top view of the drainage bottle in an embodiment of the present invention; Figure 4 This is an enlarged structural diagram of the inside of the liquid storage cylinder in an embodiment of the present invention; Figure 5 This is an exploded view of the drainage bottle in an embodiment of the present invention; Figure 6 This is a schematic diagram of the PCB-A side structure in an embodiment of the present invention; Figure 7 This is a schematic diagram of the PCB-B side structure in an embodiment of the present invention; Figure 8 This is a side view of the PCB in an embodiment of the present invention; Figure 9 This is a schematic diagram of the suction device and the loading structure of the drainage bottle in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below.

[0026] This invention proposes a non-water-sealed portable chest suction device, specifically comprising the following structure: like Figures 2-5 The diagram shown is a schematic of the drainage bottle structure of the present invention: it is a disposable ethylene oxide sterilized medical device used in conjunction with the suction device of the present invention, and its specific structure is as follows: Electrode 1: There are two sets of electrode 1, with four electrodes in each set, for a total of eight. Electrode 1 is used to connect the two circuit boards in the liquid storage chamber inside the drainage bottle. One end of electrode 1 is flat and slightly protrudes from the upper surface of the cover, while the other end is a flexible clip on the other side of the cover. The flexible clip is connected to the corresponding conductive pad on the PCB in a clamping manner. Electrode 1 and the cover are integrally molded using injection molding. The material of electrode 1 is QSn7-0.2 phosphor bronze with a gold-plated surface.

[0027] Upper cover input end 2: Integrated with the upper cover, with an inner diameter of 10mm, and connected to a thin-walled silicone hose with a wall thickness of less than 0.5mm. This hose corresponds to the input clamp valve in the suction device. Activating the clamp valve can completely block its flow path.

[0028] The upper cover input end hose 2-1 is a thin-walled silicone hose with a wall thickness of less than 0.5mm. One end is connected to the upper cover input end 2, and the other end is connected to the chest drainage tube connector 2-2. This hose corresponds to the input clamp valve 17 in the suction device 35. The clamp valve can completely block its flow channel when activated.

[0029] Chest drainage tube connector 2-2: The material is medical transparent PC with an inner diameter of 10mm. One end is connected to the upper cover input tube 2-1, and the other end is connected to the patient's chest drainage tube.

[0030] Output end 3 of the top cover: It is integrated with the top cover and has an inner diameter of 10mm. This port has a 45° bevel design. The bevel design can ensure that the drainage fluid does not stick, does not leave residue, and is not easily blocked.

[0031] Top cover 4: This is the sealing cover on the upper surface of the drainage bottle, made of medical-grade transparent PC. One side of the top cover has an input end 2, and the other side has an output end 3. The output end 3 faces the drainage bottle's storage cavity, and its end face is at a 45° bevel. The connection between the top cover and the drainage bottle's storage cylinder 6 is ultrasonically pressed. Two sets of electrodes 1, totaling eight, are embedded in the top cover, achieved through injection molding.

[0032] Airway Connection Port 5: This is the airway interface in the drainage bottle's reservoir. Airway Connection Port 5 is a component consisting of two sealing rings and a mechanical one-way valve. The inner diameter of the airway port is 6mm. When the suction device 35 is not connected, i.e., no rigid tubing is inserted into this interface, the mechanical one-way valve is closed. When the drainage bottle is connected to the suction device 35 and a rigid tubing is inserted, the mechanical one-way valve is normally open (airflow is completely unobstructed). When the drainage bottle is removed from the suction device 35, i.e., when the rigid tubing is pulled out of Airway Connection Port 5, the mechanical one-way valve automatically activates. Additionally, there are two circular sealing rings at Airway Connection Port 5 to ensure a seal between the inserted rigid tubing and this port. The function of the mechanical one-way valve is to maintain a negative pressure seal in the patient's chest cavity when the drainage bottle is connected to the patient but before the suction device 35 is connected, while simultaneously releasing positive pressure in the patient's chest cavity to prevent pneumothorax. The purpose of one-way flow is to allow gas to exit the liquid storage chamber of the flow bottle but not enter.

[0033] Drainage bottle reservoir 6: Made of medical transparent PC injection molding, it is a square barrel shape with rounded corners on all four sides. On the inner side of the two opposite sides containing the gas connection port 5, there is a slot structure 7 for inserting two PCBs. The two PCBs are placed parallel to each other with a spacing of 30mm. The top surface of the drainage bottle reservoir 6 is ultrasonically pressed to the upper cover, and the bottom surface is also ultrasonically pressed to the lower cover 8.

[0034] Slot 7: A slot-shaped device for fixing PCBs inside the drainage bottle reservoir 6. It is located on the inner side of two opposite sides of the drainage bottle reservoir 6 containing the gas connection port 5. There are two pairs of slot-shaped structures that can fix two PCBs, so that the two PCBs can be fixed in parallel with a spacing of 30mm.

[0035] The lower cover 8 is a sealing cover plate on the lower end of the drainage bottle. The material is medical transparent PC. One side of the lower cover 8 has a lower cover output end 9, which has a 10mm through hole that communicates with the drainage bottle's liquid storage chamber. The lower cover 8 and the drainage bottle's liquid storage cylinder 6 are ultrasonically pressed together.

[0036] Lower cover output end 9: integral with lower cover 8, with an inner diameter of 10mm, connected to a thin-walled silicone hose with a wall thickness of less than 0.5mm. This hose corresponds to the output clamp valve 21 in the suction device 35. The clamp valve can completely block its flow channel when activated.

[0037] The lower cover output hose 9-1 is a thin-walled silicone hose with a wall thickness of less than 0.5mm. One end is connected to the lower cover output end 9, and the other end is connected to the chest drainage bottle output connector 9-2. This hose corresponds to the output clamp valve 21 in the suction device 35. The clamp valve can completely block its flow channel when activated.

[0038] Chest drainage bottle output connector 9-2: The material is medical transparent PC with an inner diameter of 10mm. One end is connected to the lower cover output hose 9-1, and the other end is open. It can be connected to any liquid storage container, and there is no requirement for the liquid storage container to be sealed.

[0039] Upper liquid level electrode 101: Electrolytic copper plated with gold, electrode 1 has a diameter of 1.5mm, a length of 6mm, and a needle-shaped tip. There is a pair of electrodes 1, each mounted on the upper side of the PCB. These two electrodes 1 are sensors that detect when the liquid in the storage chamber has accumulated to 100ml. The two PCBs are placed mirror-image within the drainage bottle's storage chamber, hence the two electrodes 1 are diagonally distributed.

[0040] Coil 11: as Figure 6 and Figure 7 As shown, the high-frequency coupling coil 11 is etched on the PCB. It is a circular spiral coil 11 with a width of 0.15mm, a coil pitch of 0.15mm, and an inductance of L≈5.2μH in air.

[0041] PCB board 12: Two PCB boards 12 are installed parallel to each other inside the liquid storage chamber of the drainage bottle, with a spacing of 30mm. For example... Figures 6-8 As shown, double-sided conductive pads 14 connected by holes are located on sides A and B of the top of the PCB. An upper liquid level electrode 101 is mounted off-center on the upper part of the PCB, and a lower liquid level electrode 131 is mounted centered on the lower axis. A coil 11 is etched centered on the lower middle axis. Figure 6 and Figure 7 As shown, on side A (12-A) of the PCB, where the upper and lower liquid level electrodes 131 are installed and the coil 11 is etched, three traces are also etched: the outer lead of the coil 11, the lead of the upper liquid level electrode 101, and the lead of the lower liquid level electrode 131. On side B (12-B) of the PCB, a wire is etched, which is the inner lead of the coil 11. The PCB thickness is 1mm. Except for the 4mm needle-like portion at the top of the upper and lower liquid level electrodes 131 and the four double-sided conductive pads 14, the entire PCB is reliably coated with a transparent polyurethane waterproof coating. Two identical PCBs are fixedly mounted parallel to each other, 30mm apart, in a mirror image configuration of side A (12-A) to side A (12-A) through slots 7 in the drainage bottle reservoir 6. With the dimensions of the drainage bottle reservoir 6 fixed, the distance between the upper liquid level electrode 101 and the lower liquid level electrode 131 ensures that the liquid in the reservoir is 100ml.

[0042] Side A (12-A) of the PCB: It houses upper and lower liquid level electrodes 131, has a coil 11 etched on it, and three traces etched on it (leading out from the outside of coil 11, leading out from upper liquid level electrode 101, and leading out from lower liquid level electrode 131). The upper part has four conductive pads 14 connected to side B (12-B). Except for the 4mm needle-like portion of the upper and lower liquid level electrodes 131 and the four conductive pads 14, the entire side is reliably coated with a transparent polyurethane waterproof coating.

[0043] Side B of the PCB 12-B: A conductor (leading out from the inside of coil 11) is etched on it, and there are 4 conductive pads 14 at the top that are connected to side A 12-A. Except for the 4 conductive pads 14, the entire side is reliably coated with a transparent polyurethane waterproof coating.

[0044] The lower liquid level electrode 131 is made of electrolytic copper plated with gold. Electrode 1 has a diameter of 1.5 mm, a length of 6 mm, and a needle-shaped tip. There is a pair of these electrodes 1, each located on two identical PCBs placed in a mirror image, centered on the bottom axis of the PCB. This pair of electrodes 1 is a sensor for detecting the emptying of liquid in the storage chamber. Electrode 1 is 3 mm away from the bottom of the PCB to ensure the emptying of liquid.

[0045] The conductive pads 14 on the PCB: There are four conductive pads 14 on a single PCB. These four conductive pads 14 are connected to the electrodes 1 on the top cover of the drainage bottle via elastic clamping. The conductive pads 14 are double-sided, and conductive communication is achieved through holes between the A and B sides of the PCB. The four conductive pads 14 are respectively connected to the two ends of the etching, the upper liquid level electrode 101, and the lower liquid level electrode 131.

[0046] Connection point 15 on the outer side of coil 11: The connection point between the outer end of the etched coil 11 and the PCB trace, located on side A 12-A of the PCB.

[0047] Inner connection point 16 of coil 11: The connection point between the inner end of the etched coil 11 and the PCB trace, located on the B side 12-B of the PCB.

[0048] like Figure 9 The image shows the structure of the suction device 35 of the present invention, and its specific structure is as follows: Suction device 35: Must be used in conjunction with the drainage bottle in this project. Includes: input clamp valve 17, electrode holder 17, gas connection rigid tube 20, output clamp valve 21, drainage bottle chamber 19, two-way solenoid valve 23, gas container 24, small flow linear stepping flow valve 25, large flow linear stepping flow valve 26, negative pressure storage tank 27, micro-pressure negative pressure sensor, electronic level sensor 29, low negative pressure sensor 30, electromagnetic negative pressure pump 31, circuitry including MUC 32, display and input control, and small flow positive pressure pump 22.

[0049] Input clamp valve 17: Located on the upper part of the drainage bottle chamber 19 of the suction device 35, corresponding to the middle of the upper cover input end hose 2-1, which will clamp the flow channel of the hose when started.

[0050] Electrode holder 17: Located on the upper part of the drainage bottle compartment 19 of the aspirator 35, this electrode holder 17 is a pair, and each holder is equipped with four flexible electrodes 1, which contact the corresponding electrodes 1 on the drainage bottle cap to achieve conductive connection.

[0051] Drainage bottle compartment 19: The location in the suction device 35 for placing a special drainage bottle. After the drainage bottle is placed, a locking device will fix the drainage bottle in place. The locking device must be released when the drainage bottle is removed.

[0052] Air path connection rigid tube 20: This tube is located in the drainage bottle compartment 19 of the aspirator 35, with an outer diameter of 6 mm and an inner diameter of 4.5 mm. After the drainage bottle is placed, the connecting rigid tube will be reliably inserted into the air path connection port 5 of the drainage bottle. Through this air path channel, the aspirator 35 can control the air pressure of the liquid storage chamber inside the drainage bottle.

[0053] Output clamp valve 21: Located at the lower part of the suction bottle chamber 19 of the suction device 35, corresponding to the middle of the lower cover output hose 9-1, it will clamp the flow channel of the hose when started.

[0054] Small flow positive pressure pump 22: Flow rate is 5 L / min, pressure is 30 kPa, it is a positive pressure air pump, rated voltage 24VAC, 50Hz. Air is blown into the liquid storage chamber of the drainage bottle during liquid drainage to accelerate the drainage process and effectively improve liquid retention and solidification.

[0055] Dual-way solenoid valve 23: This is a two-position solenoid valve. During normal drainage, it connects the gas connection port 5 of the drainage bottle to the negative pressure gas container 24 port. When liquid drainage starts, this valve will close the negative pressure gas container 24 connection port and connect the positive pressure output port of the small flow positive pressure pump 22. After the liquid is drained, the solenoid valve will shut off the positive pressure pump 22 interface again and connect the negative pressure gas container 24 passage.

[0056] Gas Capacity 24: 800ml capacity for expanding the drainage bottle to reduce fluctuations in intrathoracic negative pressure and increase the stability of negative pressure.

[0057] Small flow linear stepper flow valve 25: slowly and linearly releases the pressure in the negative pressure storage tank 27 to the gas container 24 end (i.e. the patient's chest cavity). The maximum equivalent ventilation port diameter of this flow valve is 0.6 mm, and its port diameter can be linearly controlled between 0 and 0.6 mm by a stepper motor with a reduction gearbox.

[0058] High-flow linear stepper flow valve 26: rapidly and linearly releases the pressure in the negative pressure storage tank 27 to the gas container 24 end (i.e. the patient's chest cavity) to deal with sudden pneumothorax (positive pressure). The maximum equivalent ventilation port diameter of this flow valve is 2.0 mm, and its port diameter can be linearly controlled between 0 and 2.0 mm by a stepper motor with a reduction gearbox.

[0059] Negative pressure storage tank 27: with a capacity of 1500ml, it stores negative pressure of -20Kpa. When both the small flow linear stepping flow valve 25 and the large flow linear stepping flow valve 26 are closed, the pressure of this negative pressure storage tank 27 is maintained between -20 and -15Kpa. The purpose of this is to isolate the direct passage between the negative pressure pump and the pleural cavity to prevent the vibration pulses of the negative pressure pump from affecting the pressure control accuracy of the pleural cavity, because the pressure control accuracy of the pleural cavity is required to be better than 0.5mm water column.

[0060] Micro negative pressure sensor 28: Used to accurately collect real-time pressure in the thoracic cavity. It adopts a negative pressure sensor with temperature compensation and signal processing, and the maximum effective range is -6 kPa.

[0061] Electronic level sensor 29: Keeps the entire system (suction device 35 and drainage bottle) in a horizontal position during operation to prevent drainage fluid from entering the tubing of suction device 35 if it is tilted.

[0062] Low negative pressure sensor 30: Used to collect the real-time pressure of negative pressure storage tank 27. It adopts a negative pressure sensor with temperature compensation and signal processing, and the maximum effective range is -30 kPa.

[0063] Electromagnetic negative pressure pump 31: An electromagnetic pump with a flow rate greater than 10 L / min and a negative pressure of 60 kPa, rated voltage 24 VAC, 50 Hz.

[0064] Circuit section 32 containing MUC: The central processing unit controls the operation of the entire system and calculates the bleeding situation in the drainage fluid to give early warning.

[0065] Display and input control 33: The display includes: real-time drainage volume, cumulative drainage volume, bleeding in the drainage fluid (with audible alerts for abnormalities), actual intrathoracic pressure (changing with respiration), abnormal intrathoracic pressure display (with audible alerts), intrathoracic closure status, charging indicator, and battery level indicator during use.

[0066] Input controls include: power switch, start, stop, negative pressure setting, and emergency stop.

[0067] The working principle of this invention is as follows: During use, the chest drainage bottle is placed in the suction device 35. The device can quantify the drainage fluid in 100ml increments in real time, without the need for a water seal. It is an internally powered device that can be carried or fixed to the hospital bed. It can perform real-time blood content detection for every 100ml of drainage fluid and has a stable negative pressure suction function. The negative pressure can be set from 5-20cm water column, and it can also estimate the degree of air leakage and pneumothorax in the patient's chest cavity.

[0068] Preparation Stage: During use, place the drainage bottle in the drainage bottle compartment 19 of the suction device 35 and secure it with the locking device. After placement, the air connection tube 20 in the suction device 35 will reliably insert into the air connection port 5 of the drainage bottle. Connect the chest drainage bottle output connector 9-2 to the storage container. The storage container can be any container capable of holding drainage fluid, such as a bottle or bag. There are no requirements for the container's airtightness, water seal, or graduated measurement. After completing the above, turn on the power switch of the suction device 35. At this time, the input clamp valve 17 and the output clamp valve 21 of the suction device 35 will activate simultaneously, clamping the upper cover input hose 2-1 and the lower cover output hose 9-1. After clamping, the suction device 35 will start according to the negative pressure value set by the operator. When the negative pressure in the drainage bottle's storage chamber reaches the set suction negative pressure, the system will perform initial reference detection and calculation on the empty drainage bottle, first measuring the air reference resonant frequency. and air quality factor Then, the relevant baseline quantities are calculated, and "Ready" is displayed on the screen after completion.

[0069] Once ready, connect the chest drainage tube connector 2-2 at the top of the drainage bottle to the patient's chest tube. Press the start button on the device to begin operation. During operation, the device will open the input clamp valve 17 to allow the upper cap input hose 2-1 to flow freely, while the output clamp valve 21 remains in the activated position, meaning the lower cap output hose 9-1 is clamped. Fluid from the patient's chest cavity will enter the drainage bottle's reservoir. When the fluid touches the upper liquid level electrode 101 mounted on the PCB in the reservoir, it indicates that the drainage fluid has reached 100ml. Immediately, the input clamp valve 17 is activated to clamp the upper cap input hose 2-1. The blood content in the drainage fluid is detected by a pair of high-frequency coils 11 on the PCB using magnetic coupling, and the results are given (normal exudation, active bleeding warning, severe bleeding alarm). After the detection is completed... Open the output clamp valve 21, so that the lower cover output hose 9-1 is in a conductive state. At the same time, the double-way solenoid valve 23 in the suction device 35 will switch the air route connected to the drainage bottle from the previous negative pressure gas container 24 port to the positive pressure output port of the small flow positive pressure pump 22. The air pump blows air into the liquid storage chamber, so that the liquid flows out quickly and reduces the occurrence of residue and condensation sticking to the wall. After the lower liquid level electrode 131 installed on the PCB detects that the liquid has been emptied, the double-way solenoid valve 23 in the suction device 35 will disconnect the air route connected to the drainage bottle and the positive pressure output port of the small flow positive pressure pump 22, and instead connect the air route of the drainage bottle to the negative pressure gas container port. After the pressure value in the liquid storage chamber of the drainage bottle reaches the set value, the device will open the input clamp valve to make the upper cover input hose 2-1 unobstructed and start a new cycle.

[0070] Both the upper liquid level electrode 101 and the lower liquid level electrode 1 detect the liquid level using the AC resistance method, and both use a 50 microamp 10 Hz sine wave voltage source for impedance detection.

[0071] The airway connection port 5 of the drainage bottle contains a component including a sealing ring and a mechanical one-way valve. When no suction device is connected and no rigid tubing is inserted into this port, the mechanical one-way valve is closed. When the drainage bottle is connected to the suction device and a rigid tubing is inserted, the mechanical one-way valve is normally open (keeping the airway unobstructed). When the drainage bottle is removed from the suction device, i.e., when the rigid tubing is pulled out from this airway connection port 5, the mechanical one-way valve automatically activates. Additionally, there are two circular sealing rings at airway connection port 5 to seal the inserted rigid tubing against this port. The function of the mechanical one-way valve is to maintain a leak-proof negative pressure seal in the patient's chest cavity when the drainage bottle is connected to the patient but before the suction device is connected, while simultaneously releasing positive pressure in the chest cavity to prevent pneumothorax. This is also the reason for the one-way valve design; its one-way function allows gas in the drainage bottle's reservoir to escape but not enter.

[0072] PCB inside the drainage bottle's storage chamber Two PCBs are mounted in parallel mirror images within the liquid storage chamber of the drainage bottle, spaced 30mm apart. Both sides A and B of the top of the PCBs have double-sided conductive pads connected via holes. An upper liquid level electrode 101 is mounted slightly off-center at the top, and a lower liquid level electrode 1 is mounted centrally at the bottom. A coil 11 is etched along the central axis slightly off-center at the bottom. On side A of the PCB, which houses the upper and lower liquid level electrodes 1 and the etched coil 11, three traces are etched: the outer lead of coil 11, the lead of upper liquid level electrode 101, and the lead of lower liquid level electrode 1. On side B of the PCB, a wire is etched, which is the inner lead of coil 11. The PCBs are 1mm thick, and except for the 4mm needle-like portion at the top of the upper and lower liquid level electrodes 1 and the four double-sided conductive pads, the entire surface is reliably coated with a transparent, waterproof polyurethane coating. Two identical PCBs are mounted in parallel with their surfaces facing each other, through slots 7 in the drainage bottle reservoir 6, at a distance of 30mm.

[0073] With the dimensions of the drainage bottle reservoir 6 fixed, the distance between the upper liquid level electrode 101 and the lower liquid level electrode 1 ensures that the liquid capacity in the reservoir is 100ml.

[0074] Suction The suction device must be used in conjunction with the aforementioned drainage bottle. It includes: an input clamp valve, a pair of electrode holders, a rigid gas connection tube, an output clamp valve, a drainage bottle chamber, a two-way solenoid valve, a gas container, a small-flow linear stepping flow valve, a large-flow linear stepping flow valve, a negative pressure reservoir, a micro-negative pressure sensor, an electronic level sensor, a low-negative pressure sensor, an electromagnetic negative pressure pump, a circuit section containing a MUC, a display and input control section, and a small-flow positive pressure pump.

[0075] The operating process is as follows: When both the small-flow and large-flow linear stepper valves are closed, the electromagnetic negative pressure pump first draws the pressure in the negative pressure storage tank to -20 kPa. This design prevents the pulse vibrations from the electromagnetic pump from being transmitted through the air path to the thoracic cavity circuit and the pressure sensor, thus affecting the stability of the thoracic cavity negative pressure. This negative pressure storage tank acts as an isolation mechanism. When the pressure in the negative pressure storage tank reaches 15 kPa, the electromagnetic negative pressure pump restarts and draws it back to -20 kPa. When the electromagnetic negative pressure pump starts, both the small-flow and large-flow linear stepper valves must be simultaneously closed to ensure that vibration interference to the air path is effectively isolated.

[0076] During operation, two stepper flow valves smoothly transfer negative pressure to the air container connected to the patient's chest cavity (connected in series with a chest drainage bottle). Under normal circumstances, the high-flow linear stepper flow valve is closed, with only the low-flow linear stepper flow valve operating. The flow rate of this valve is precisely controlled by a stepper motor with a reduction gearbox, ensuring accurate and stable pressure control. In the event of a sudden pneumothorax, the high-flow linear stepper flow valve activates, rapidly removing positive pressure to maintain the set negative pressure. Both linear flow valves are precisely controlled using fuzzy PID calculations by the MCU.

[0077] The double-way solenoid valve between the rigid tube and the gas container in the gas circuit is used to connect to the positive pressure outlet of the small flow positive pressure pump when the drainage liquid is released from the storage bottle, so as to blow air into the storage chamber.

[0078] In case of an emergency or when the emergency stop button is pressed: the device will immediately activate the input clamp valve to clamp the upper cover input hose 2-1, release the output clamp valve, and simultaneously display an emergency situation on the screen and issue an audible alarm.

[0079] The aforementioned negative pressure accumulator, gas reservoir, two linear flow valves with different flow rates, and two negative pressure sensors with different ranges are all designed for precise pressure control. This is because chest cavity pressure control requires high precision and the ability to instantly remove positive pressure. The operation of a negative pressure pump is always accompanied by airflow pulsations and mechanical acoustic interference. The negative pressure accumulator isolates and blocks all adverse factors affecting the negative pressure pump, while the two linear flow valves ensure precise and stable flow and pressure control.

[0080] The two clamp valves and the corresponding input and output silicone tubing are designed to ensure the airtightness of the chest cavity throughout the entire process, whether during normal drainage or when the drainage fluid is drained.

[0081] There are two reasons why thoracic suction and drainage are needed: air leakage in the thoracic cavity (including pneumothorax) and the need to drain harmful fluid from the thoracic cavity. This equipment can provide auxiliary judgment for both of these points. The equipment has a real-time fixed-cycle flow rate display function for fluid drainage. The degree of "air leakage" in the thoracic cavity is indirectly calculated by the on / off state of two linear flow valves with different flow rates. Since both linear flow valves are implemented by fuzzy PID calculation of the MCU, a reference result of the degree of air leakage in the thoracic cavity can be given based on the data model algorithm.

[0082] Based on the non-water-sealed portable chest suction device of the present invention, the present invention also proposes a method for calculating the blood content in the drainage fluid using magnetic coupling. This is a non-contact, periodic, automated monitoring method for the blood content of postoperative pleural drainage fluid. It employs magnetic coupling detection technology with two high-frequency coils (11) to simultaneously monitor resonant frequency shift and quality factor (Q) changes—a dual-mode method. The frequency-mode calculation reflects the magnetic properties of blood (hemoglobin concentration), while the Q-mode calculation reflects the electrical properties of the fluid (conductivity). The two sets of data are cross-validated to improve measurement reliability. The following calculation method is only applicable to the hardware structure of this device and is a specific, adaptive calculation method, not a universally applicable one. The final bleeding state (blood concentration CHB) of this device is based on the frequency-mode calculation; the Q-mode calculation result is only used for verification.

[0083] Principle: The magnetic properties of blood, specifically the paramagnetic nature of deoxyhemoglobin, contrast with the diamagnetic composition of pleural effusion without bleeding. Changes in the hemoglobin concentration in the drainage fluid cause changes in the overall permeability of the medium, thereby altering the resonant frequency of the coil 11 system—the concentration-frequency relationship. Simply put, the permeability change of the drainage fluid between the two coils 11 is primarily determined by the paramagnetic deoxyhemoglobin. Bleeding alters the magnetic coupling coefficient between the two coils 11, thus affecting the induced voltage and impedance of the secondary coil 11.

[0084] This device employs both frequency and Q-value calculation methods under a magnetic coupling system, namely frequency modulus and Q-value modulus. The frequency modulus calculation method reflects the magnetic properties of blood (hemoglobin concentration), while the Q-value modulus calculation method reflects the electrical properties of the liquid (conductivity). Two identical coils 11 are installed on both sides inside the drainage container, serving as transmitter and receiver respectively, thus forming the magnetic coupling system.

[0085] The core detection and calculation method is characterized by: measuring the resonant frequency shift of the LC resonant circuit and the quality factor Q of the same resonant circuit. Then, the blood concentration (CHB) is calculated based on the frequency shift, and the reliability of the measurement results is verified by the change in the Q value.

[0086] Basic parameters: Two identical coils 11 are placed mirror images of each other on a parallel coaxial line with a spacing of 30mm in the liquid storage chamber of the drainage bottle. One is a primary coil 11 (excitation), and the other is a secondary coil 11 (receiving). Both coils 11 are made by PCB etching. They are circular spiral coils 11 with a width of 0.15mm, a turn pitch of 0.15mm, an inductance of L≈5.2Mh in air, a theoretical resonant frequency of f0=2.000MHz, and a parallel resonant capacitance of C=1218 pF.

[0087] calculate Related Symbol Table

[0088] Table of Empirical Constants (The following constants are all derived from statistical summaries based on the hardware system of this device)

[0089] Calculations and Examples Baseline measurements and calculations (one-time calculation, when replacing the chest drainage bottle) Step 1: Measure the original baseline data After the new drainage bottle is installed, measure the following two initial values:

[0090] The measured air resonant frequency was directly sampled by the hardware and calculated by the MCU. The measured air quality factor was obtained by measuring the 3dB bandwidth of the resonant curve according to industry standards. Example value: Step 2: Calculate the theoretical reference point Based on empirical constants, calculate the theoretical resonant parameters for pleural effusion and whole blood:

[0091] Where the empirical constant is: Substitute into the calculation: Step 3: Calculate the frequency boundary for state determination The three boundary frequencies are determined by the air reference frequency and a fixed offset: Wherein the boundary offset constant: Substitute into the calculation:

[0092] At this point, the benchmark measurement is complete. , , , , , , It is stored for use in all subsequent cycle calculations.

[0093] 4.3.2 Real-time measurement and calculation (repeated in each cycle) Step 4: Measure the current real-time data For each measurement cycle (after filling 50ml), the following two raw values ​​are measured:

[0094] The measured resonant frequency was directly sampled by the hardware and calculated by the MCU. The measured quality factor was obtained by measuring the 3dB bandwidth of the resonant curve according to industry standards. Example value: 4.3.3 Frequency Module Calculation Step 5: Calculate the frequency offset Frequency offset is defined as the difference between the measured frequency and the theoretical frequency of pleural effusion: Substitute into the calculation: Step 6: Calculate hemoglobin concentration (frequency modulus) Hemoglobin concentration is directly proportional to frequency shift: Wherein the frequency sensitivity constant is: Substitute into the calculation:

[0095] 4.3.4 Q-value modulus calculation (for verification) Step 7: Calculate the reciprocal of Q.

[0096] Substitute into the calculation: Step 8: Calculate the reciprocal offset of the Q value Q-value reciprocal offset is defined as the difference between the measured reciprocal of the Q-value and the theoretical reciprocal of the Q-value for pleural effusion: Substitute into the calculation: Step 9: Calculate hemoglobin concentration (Q value modulus) Hemoglobin concentration is directly proportional to the shift of the reciprocal of the Q value: Where the Q-value is the sensitivity constant: Or write: Substitute into the calculation: Consistency check and status assessment Step 10: Calculate the difference between the two modes Substitute into the calculation: Step 11: Consistency Check Dual-mode difference threshold constant: judge: If the device screen displays "Measurement Verification Suggestion", medical staff can wait for the measurement result of the next 100ml. If "Measurement Verification Suggestion" appears continuously, a new chest drainage bottle needs to be replaced, or the drainage fluid needs to be manually extracted for testing.

[0097] Step 12: Status Determination Compare the measured frequency with the three boundary frequencies: Substitute and compare: and Automatically satisfied therefore: Re-examine the interval definition: :normal :warn :Call the police like Is this a warning or an alarm? According to clinical settings arrive The range between 1,999,999.898 and 2,000,000.018 is within the warning zone, because only values ​​below 1,999,999.898 are considered warning. That's when you should call the police.

[0098] so:

[0099] Step 13: Final Output Clinical comparison table of 584 cases The gold standard for determination (the industry-standard red blood cell concentration) Normal exudation: RBC ≤ 1.0 × 10 12 / L Warning of active bleeding: 1.0 × 10 12 / L < RBC ≤ 3.0 ×10 12 / L Serious bleeding alarm: RBC > 3.0 × 10 12 / L Note: The gold standard is red blood cell concentration ( / L). The 100 mL sample box / drainage bottle in this project is only a sampling container.

[0100] Table of Clinical Comparison Results of 584 Cases

[0101] in conclusion This study included pleural drainage fluid samples from 584 patients after pleural surgery. The clinically accepted red blood cell concentration counting method was used as the gold standard to conduct preliminary clinical validation of the pleural drainage bleeding monitoring device.

[0102] The results showed that the overall accuracy rate of the equipment in judging the three levels of normal exudation, active bleeding warning, and severe bleeding alarm was 97.26%.

[0103] The accuracy rate for judging normal exudation was 97.38%, the accuracy rate for warning of active bleeding was 97.32%, and the accuracy rate for alarming severe bleeding was 96.81%.

[0104] All non-compliant samples appeared in the threshold range, with no serious cross-level misjudgments, indicating that the overall discrimination performance of the equipment is good and the technical approach is feasible.

[0105] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention are considered to have remained within the scope of protection of the present invention.

Claims

1. A non-water-sealed portable chest suction device, characterized in that, Includes a suction device and a disposable monitoring drainage bottle detachably connected to the suction device; The drainage bottle contains two mirror-symmetrically arranged PCB boards. On the opposing surfaces of the two PCB boards, upper liquid level electrodes are mounted on the upper part and lower liquid level electrodes are mounted on the lower part, and symmetrical high-frequency coupling coils are etched in the middle and lower parts, forming a magnetic coupling resonance system. The suction device is connected to the liquid storage cylinder of the drainage bottle via a gas connection tube, and a positive pressure pump and a negative pressure pump are used to provide a positive or negative pressure environment inside the drainage bottle.

2. The non-water-sealed portable thoracic suction device according to claim 1, characterized in that, The drainage bottle includes an upper cap, a lower cap, and a liquid storage cylinder; The upper cover is a sealing cover plate on the upper end face of the liquid storage cylinder. The middle part of the upper cover is an input pipe. The input end of the input pipe is connected to the chest drainage tube connector through an input end hose. An input clamp valve is correspondingly connected to the input end hose. The lower cover is a sealing cover plate for the lower end face of the liquid storage cylinder. The middle part of the lower cover is an output pipe. The output end of the output pipe is connected to the output connector of the drainage bottle through an output end hose. An output clamp valve is correspondingly connected to the output end hose. The side wall of the liquid storage cylinder is provided with a gas connection port for connecting the gas connection rigid pipe.

3. The non-water-sealed portable thoracic suction device according to claim 2, characterized in that, The liquid storage cylinder has two pre-set PCB slots for inserting the PCB board.

4. The non-water-sealed portable thoracic suction device according to claim 2, characterized in that, The PCB board has four conductive pads at its end, which are respectively connected to the two ends of the coil, the upper liquid level electrode, and the lower liquid level electrode. The surface of the upper cover is provided with two sets of electrodes, four in each set, and the eight electrodes are electrically connected to the eight conductive disks respectively.

5. The non-water-sealed portable thoracic suction device according to claim 1, characterized in that, The surface of the PCB board is coated with a transparent polyurethane waterproof coating.

6. The non-water-sealed portable thoracic suction device according to claim 4, characterized in that, The aspirator includes a drainage bottle compartment for holding the drainage bottle. The drainage bottle is equipped with an input clamp valve, an output clamp valve, and an electrode holder. The electrode holder is electrically connected to the electrodes on the top cover.

7. The non-water-sealed portable thoracic suction device according to claim 1, characterized in that, The suction device also includes a small-flow positive pressure pump, a gas container, a negative pressure storage tank, and an electromagnetic negative pressure pump; The gas connection tube is equipped with a two-way solenoid valve and is connected to the small-flow positive pressure pump; one end of the gas connection tube is connected to the gas container, and the gas container is equipped with a micro negative pressure sensor; the gas container is connected to the negative pressure storage tank through a small-flow linear stepping flow valve and a large-flow linear stepping flow valve respectively; the negative pressure storage tank is connected to the electromagnetic negative pressure pump, and the negative pressure storage tank is equipped with a low negative pressure sensor.

8. The non-water-sealed portable thoracic suction device according to claim 1, characterized in that, The aspirator also includes a central processing unit and a display input control module.

9. The non-water-sealed portable thoracic suction device according to claim 1, characterized in that, The magnetically coupled resonance system executes the following monitoring logic: S1: Reference Measurement: The system acquires the air reference resonant frequency during the initialization phase. and air quality benchmark factor ; S2: Real-time sampling: When the drainage fluid touches the upper liquid level electrode, the system collects the current measured resonant frequency. Compared with the measured quality factor ; S3. Dual-mode concentration calculation: Frequency mode concentration calculation: ,in This is the frequency sensitivity coefficient. The frequency offset of pleural effusion relative to air; Q-value modulus concentration calculation: based on measured quality factor. relative to air reference quality factor The reciprocal increment is used to calculate the Q-value modulus concentration. S4. Consistency check: Calculate the concentration difference between the two models. ,like If it is less than the preset threshold, then As the final hemoglobin concentration output; S5, State determination: compare the measured resonant frequency f_{meas}fmeas with multiple preset frequency boundaries, if Frequency below alarm threshold If so, it is determined that postoperative active bleeding has occurred and an alarm is triggered.

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