Implantable portal vein and subordinate branch vein blood sampling system thereof

Abstract

The invention discloses an implantable portal vein and branch vein blood sampling system and blood sampling method thereof, and belongs to the technical field of medical instruments. The blood sampling system comprises an implant unit which can be completely implanted into a body, and the implant unit is provided with a blood flow path communicated with a target blood vessel, a driving unit used for generating negative pressure, a control unit and a wireless communication unit. The control unit receives an in-vitro instruction through the communication unit and accurately controls working parameters of the driving unit so as to extract a blood sample with a preset volume. In a preferable scheme, the system is integrated with a pressure sensor to realize closed-loop monitoring, and a sample can be output through a subcutaneous port or a built-in blood storage cavity. By means of an implantable wireless control scheme, long-term, accurate and repeatable collection of portal vein system blood is achieved, trauma, infection risks and operation errors caused by traditional repeated puncture are effectively avoided, and a safe and reliable solution is provided for dynamic blood flow monitoring and high-frequency inspection requirements.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to an implantable medical device for intravascular blood collection, particularly a portal vein and its tributary vein blood collection system and its operating method that can be implanted long-term and allows for precise and controllable repeated blood collection via external wireless commands. Furthermore, this invention is also closely related to the fields of medical robots and remote control, as well as long-term dynamic sampling and monitoring of body fluids. Background Technology

[0002] Portal venous blood testing has irreplaceable clinical value for liver diseases (such as cirrhosis and hepatocellular carcinoma), portal hypertension, gastrointestinal endocrine assessment, and tumor metastasis diagnosis. Portal venous blood can more directly reflect the liver's metabolic state, tumor markers in visceral circulation, pathogens, and cell-free nucleic acids, exhibiting higher diagnostic sensitivity and specificity compared to peripheral blood. Therefore, obtaining portal venous blood samples safely and effectively is an important clinical requirement.

[0003] Currently, the main techniques for obtaining portal vein blood in clinical practice include: percutaneous transhepatic portal vein sampling, direct intraoperative puncture or catheterization, and transjugular intrahepatic portosystemic shunt. However, these portal vein sampling techniques are essentially categorized as 'temporary, invasive punctures,' and their common limitation is the inability to achieve long-term, minimally invasive, procedural, and high-precision repeated blood sampling. This makes it difficult to achieve dynamic and continuous monitoring of the physiological and pathological aspects of the portal venous system in clinical practice and research, thus limiting the development of related disease management and cutting-edge research (such as liquid biopsy based on cell-free nucleic acid in portal vein blood).

[0004] Therefore, there is an urgent need for a new portal vein blood sampling technology that can be implanted long-term, activated on demand, and precisely controlled to overcome the operational risks, patient suffering, sample errors, and infection risks caused by repeated punctures. Summary of the Invention

[0005] This invention aims to overcome the aforementioned deficiencies of the prior art and provide a novel blood collection system for the portal vein and its tributary veins. Specifically, the technical problem this invention addresses is: how to provide a device and method for long-term, safe, convenient, and highly accurate repeated blood collection from the portal vein system, reducing operational difficulty and technical dependence, minimizing puncture trauma, infection risk, and sampling errors, and facilitating dynamic monitoring. To solve the above technical problem, the basic concept of this invention is to provide a fully implantable, externally wirelessly controlled miniature blood collection system. This system, through an implantable unit anastomosed with the portal vein or its tributary veins, automatically performs precise negative pressure blood collection upon receiving external commands and safely delivers the blood sample to a preset location (in vivo blood storage chamber or externally).

[0006] This invention is implemented as follows.

[0007] An implantable portal vein blood collection system is characterized in that the system comprises an implant unit, an external control unit, and a sample collection unit; the implant unit is designed as a biocompatible structure that can be left in the body for a long time, and its core includes a system body and a drive module, a vascular interface, a blood collection passage and valves, and a control and communication module; the system body and the drive module are used to generate precise and controllable negative pressure to drive blood flow; the vascular interface is used for surgical anastomosis with the portal vein or its tributaries to establish a closed blood passage; the blood collection passage and valves are used to form a closed flow path from the blood vessel to the sample outlet, and are equipped with valves to prevent blood backflow and contamination; the control and communication module is used to receive external wireless signals and control the operation of the drive module, and may include built-in sensors (such as pressure and flow sensors) for monitoring the blood collection status.

[0008] In a preferred embodiment, an implantable portal vein and its tributary vein blood sampling system is characterized in that the blood sampling system includes an implant unit, a drive unit, a control unit, and a communication unit; the implant unit is provided with a blood flow path communicating with the portal vein or its tributary veins and can be completely implanted into the body; the drive unit is connected to the blood flow path and is used to generate negative pressure to drive blood flow; the control unit is used to control the operating parameters of the drive unit; the communication unit is used to wirelessly communicate with an external device; the control unit is configured to receive control commands from an external device through the communication unit and precisely control the drive unit according to the commands to extract a predetermined volume of portal vein and its tributary vein blood sample.

[0009] In a preferred embodiment, the blood flow path of the blood collection system includes: a vascular interface for anastomosis with a blood vessel, a main flow channel communicating with the vascular interface, and a sample output channel for guiding the collected blood to the outside of the body. The drive unit is disposed on either the main flow channel or the sample output channel.

[0010] In a preferred embodiment, the blood flow path of the blood collection system includes a sample output tube whose end is connected to a subcutaneous port that can be punctured percutaneously.

[0011] In a preferred embodiment, the blood flow path of the blood collection system includes a sample output tube whose end is connected to a blood storage chamber for temporarily storing the extracted blood.

[0012] In a preferred embodiment, the blood collection system further includes a pressure sensor for monitoring the pressure within the blood flow path, the pressure sensor being signal-connected to the control unit; the control unit is configured to adjust the operating parameters of the drive unit in real time or determine abnormal states in the blood collection process based on the feedback signal from the pressure sensor.

[0013] In a preferred embodiment, the driving unit in the blood flow path of the blood collection system is one of a micro piezoelectric system, a micro peristaltic system, or a micro piston system driven by a shape memory alloy.

[0014] In a preferred embodiment, the blood flow path of the blood collection system is further provided with at least one one-way valve to prevent blood backflow and / or air ingress.

[0015] In a preferred embodiment, the communication unit of the blood collection system is a radio frequency communication module, which is also used to receive wireless power transmission from external devices in order to power the drive unit and the control unit.

[0016] In a preferred embodiment, the control unit of the blood collection system has at least two different blood collection programs preset, the blood collection programs being associated with different negative pressure curves, blood collection durations and / or target volumes.

[0017] A method for repeated blood sampling of the portal vein and its tributary veins, characterized in that the blood sampling system described in this invention is used for repeated blood sampling of the portal vein and its tributary veins, and the method includes the following steps: S1: A control command containing blood collection parameters is sent percutaneously to the communication unit of the blood collection system; S2: The control unit of the blood collection system drives the drive unit to generate a precise and controllable negative pressure according to the instruction; S3: Under the negative pressure, a predetermined volume of blood from the portal vein or its tributary veins is drawn to the target location via the blood flow path.

[0018] In a preferred embodiment, a method for repeated blood collection from the portal vein and its tributary veins is characterized in that, in or after step S2 described in

[0017] above, step S4 is further included: monitoring the blood collection status by a pressure sensor installed in the blood flow path and feeding back the status data to an external device through the communication unit; and / or, when an abnormal pressure is detected, automatically stopping blood collection and sending an alarm message.

[0019] The beneficial effects of this invention: Compared with the prior art, the implantable portal vein and its tributary vein blood collection system and its operation method provided by the present invention have the following significant advantages: S1. Achieves minimally invasiveness and repeatability: Long-term, multiple blood collections can be achieved through a single surgical implantation, completely avoiding the pain of repeated percutaneous punctures and vascular damage to patients, making it particularly suitable for clinical scenarios requiring dynamic monitoring of portal vein parameters; S2. Improved sampling accuracy and safety: Programmed control of negative pressure parameters (such as pressure and duration) allows for precise control of blood collection volume and speed, reducing the risk of hemolysis and improving sample quality. The closed flow path design and anti-backflow valve significantly reduce the risk of infection and cross-contamination caused by blood exposure. S3. Reduced operational difficulty and human error: Medical staff can wirelessly control the device externally, making the operation simple and intuitive, reducing the extremely high requirements for the operator's puncture skills, and reducing errors caused by the instability of manual operation; S4. It achieves standardization and monitorability of the sampling process: Built-in sensors can provide real-time feedback on the blood collection status (such as tubing pressure, whether it is completed), making each sampling process standardized, recordable, and traceable, providing a reliable tool for clinical research and precision medicine; S5. Expands the possibilities for clinical diagnosis and research: It provides an ideal sample acquisition platform for advanced diagnostic technologies such as free nucleic acid testing that require high-frequency, standardized blood samples, which is carried out by our company and in the field, and helps in the early diagnosis, efficacy evaluation and mechanism research of diseases. Attached Figure Description

[0020] Figure 1 A simplified flowchart illustrating the implementation of this invention.

[0021] Figure 2 A schematic diagram of the implantable portal vein and its tributary vein blood collection system described in this invention.

[0022] Figure 3 A simplified structural diagram of the implant unit 2 described in this invention.

[0023] Figure 4 A simplified schematic diagram of the working process of the wireless controller 3 described in this invention.

[0024] Figure 5 Flowchart of the portal vein blood collection method described in this invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention. Figure 1 This is a simplified flowchart of the implementation of this invention.

[0026] Example 1: Operational Procedure of an Implantable Portal Vein and its Tributary Veins Blood Collection System Figure 2 This is a schematic diagram of the overall system for blood collection from the implantable portal vein and its tributary veins as described in this invention. Figure 3 This is a simplified structural diagram of the implant unit 2 described in this invention. The implantable portal vein and its tributary vein blood collection system provided by this invention includes an implant unit 2 that can be completely implanted into the body, an external wireless controller 3, and a sample collection bottle 4, as shown below. Figure 2 As shown. Its operating logic is as follows: the external wireless controller 3 sends an encrypted command containing specific parameters (such as blood collection volume and speed); the implant unit 2 receives the command via wireless communication, and its internal control unit 18 ( Figure 3 After decoding, it precisely drives the micro piezoelectric pump 9 ( Figure 3 The system operates to generate a controllable negative pressure, thereby allowing a predetermined volume of portal venous system blood to be discharged through sample output tube 14. Figure 3 4. Sample collection bottle extracted from the body; like Figure 3 As shown, the implant unit 2 includes a shell 5 made of biocompatible titanium alloy or medical-grade PEEK material. The shell 5 integrates the following core components: a drive and pumping module, a blood collection and flow path system, and a control and sensing module; The drive and pumping module includes a miniature piezoelectric pump 9 as a negative pressure source, which is connected to the blood collection path 11 via a precision valve miniature solenoid valve 10. Furthermore, the drive voltage, frequency, and stroke of the miniature piezoelectric pump 9 can be precisely adjusted by a control circuit to control the negative pressure and suction speed. The blood collection and flow path system includes a vascular anastomosis interface 12, a main flow tube 13, and a sample output tube 14; The vascular anastomosis interface 12 is a medical silicone tube with an anti-friction structure, one end of which is used for end-to-side anastomosis with a tributary of the portal vein (such as the splenic vein). The main flow conduit 13 is used to connect the vascular anastomosis interface 12 to the miniature piezoelectric pump 9; The sample output tube 14 is used to pass through a skin tunnel after the micro piezoelectric pump 9, and its end is connected to a subcutaneous puncture port 16 (such as a repeatable puncture diaphragm). The subcutaneous puncture port 16 is embedded subcutaneously (such as below the costal margin) to facilitate percutaneous connection to the in vitro sample collection bottle 4. The main flow line 13 is equipped with a one-way valve 17 to prevent blood backflow and air from entering the blood vessels; The control and sensing module 8 includes a control unit 18 (ASIC chip), a miniature pressure sensor 19, and a radio frequency (RF) communication and energy receiving coil 20. The control unit 18 (ASIC chip) is responsible for receiving wireless signals and driving the miniature piezoelectric pump 9 and the solenoid valve 10. The miniature pressure sensor 18 is located near the vascular anastomosis interface 12 and is used to monitor the venous pressure and negative pressure status at the blood collection point in real time. The radio frequency (RF) communication and energy receiving coil 20 is used to receive commands and wireless energy from the wireless controller 3. Figure 4 This is a simplified schematic diagram of the workflow of the wireless controller 3 described in this invention. The wireless controller 3 includes a user interface 21 and a transmitting coil 23. The user interface 21 allows medical personnel to set the blood collection volume (e.g., preset 1mL, 3mL, 5mL levels) and the blood collection speed (slow / standard / fast). After setting, the wireless controller 3 sends an encrypted start command and energy to the implant unit 2 through the transmitting coil 23. Simultaneously, the wireless controller 3 can receive and display feedback data from the miniature pressure sensor 18, forming a closed-loop control. If tubing blockage or abnormal pressure is detected, it can automatically stop blood collection and issue an alarm. Figure 5 This invention demonstrates a method for performing a single blood collection from the portal vein and its tributary veins, including: Step S101: Preparation. Disinfect the skin at the subcutaneous puncture port 16, and connect the sterile in vitro sample collection bottle 4 to port 16 via a special puncture needle; Step S102: Command transmission. Set the blood collection parameters (e.g., volume 3mL, speed standard) on the wireless controller 3 and confirm transmission; Step S103: Implant activation. After receiving the instruction, the control unit 18 of the implant unit 2 sequentially opens the solenoid valve 10 and starts the micro piezoelectric pump 9 to operate according to the preset parameters; Step S104: Blood Collection and Monitoring. Negative pressure pumps portal vein blood through the vascular anastomosis interface 12 and the main flow tubing 13, then through the sample output tube 14 into the sample collection bottle 4. The miniature pressure sensor 19 provides real-time data feedback to the wireless controller 3, ensuring a smooth process. Step S105: Completion and Reset. Upon reaching the preset volume or time, the control unit 18 automatically stops the micro piezoelectric pump 9 and closes the solenoid valve 10. The collection bottle 4 is disconnected, and one blood collection session is complete. Very little blood remains in the tubing, and it is sealed by the one-way valve 17 to prevent blood or gas from flowing back into the portal vein.

[0027] Example 2: Operating program code for an implantable portal vein and its tributary vein blood sampling system The following code is the operating program code of an implantable portal vein and its tributary vein blood collection system according to the present invention. It fully implements the control system described in this patent specification and includes all necessary safety mechanisms and control logic, which is an important proof of the feasibility of this patent application:

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[0042] Example 3: An implantable portal vein and its tributary vein blood sampling system (based on a piezoelectric system and subcutaneous port) 1. The micro piezoelectric pump 9 operates within a voltage range of 5-24V. By changing the amplitude and frequency of the applied voltage, the magnitude of the negative pressure and the flow rate generated can be precisely controlled. In this embodiment, the effective working negative pressure generated is controlled between -50 mmHg and -150 mmHg. 2. The vascular anastomosis interface 12 is a 20mm long, 2.0mm inner diameter expanded polytetrafluoroethylene (ePTFE) tube, which is anastomosed end-to-side with the splenic vein during the operation; the main flow conduit 13 is a 1.5mm inner diameter, 0.5mm wall thickness medical-grade polyurethane soft tube, connecting the vascular anastomosis interface 12 to the inlet of the micro piezoelectric pump 9; the sample output tube 14 connects to the outlet of the micro piezoelectric pump 9, and its end connects to the subcutaneous puncture port 16. The base of the subcutaneous puncture port 16 is made of titanium alloy, and its core is a silicone diaphragm that can withstand more than 1000 punctures by a 22G puncture needle; a duckbill-shaped one-way valve 17 is installed on the main flow conduit 13 connected to the micro piezoelectric pump 9 to prevent blood or gas from flowing back into the portal vein; 3. The control unit 18 is an application-specific integrated circuit (ASIC) chip responsible for all logic control; the radio frequency (RF) communication and energy receiving coil 20 operates in the 402MHz MICS band. It simultaneously receives commands and wireless energy from the external controller 3. The received energy is rectified and regulated by the power management circuit of the micro piezoelectric pump 9 to power the entire system unit and can also charge the built-in micro energy storage components (such as supercapacitors); 4. A miniature pressure sensor 19 is integrated into the main flow channel 13 near the vascular anastomosis interface 12. Its real-time monitoring data is sent to the control unit 18; the control unit 18 is pre-programmed with procedures such as "standard blood collection" (target flow rate 2 mL / min) and "slow blood collection" (target flow rate 1 mL / min). During operation, it compares the readings of the miniature pressure sensor 19 with the pre-programmed target pressure curve. For example, if the actual pressure is lower than the target lower limit (e.g., -110 mmHg), the piezoelectric system drive frequency is automatically reduced by 5% to prevent adhesion to the blood vessel wall. 5. During blood collection, after disinfecting the skin, use a dedicated coreless puncture needle to insert into the silicone septum of the subcutaneous puncture port 16 and connect the vacuum blood collection tube. The user selects "Collect 3mL of blood, standard mode" on the touchscreen of the wireless controller 3 and clicks start. The subsequent steps S103 to S105 described in Example 1 are executed automatically. After approximately 90 seconds, the controller displays "Blood collection complete," indicating that the blood has been safely stored in the blood collection tube.

[0043] Example 4: An implantable portal vein and its tributary vein blood collection system (based on a peristaltic system and an internal blood storage chamber) This embodiment provides a variation that avoids conventional percutaneous puncture: 1. Driving source modification: The miniature piezoelectric pump 9 in the above embodiment is replaced with a miniature peristaltic system as the driving source. The miniature peristaltic system generates directional flow through three rollers that sequentially roll the silicone tubing, and has the advantages of being valve-free and less prone to clogging; 2. Subcutaneous puncture port modification: Subcutaneous puncture port 16 is removed, and a cylindrical blood storage chamber with a volume of 2.0 mL is added inside the implant unit 2. A three-way valve is added to the main access tubing 13; 3. Workflow Variation: S1. Blood collection stage: The control unit 18 controls the added three-way valve to connect the main flow pipeline 13 with the blood storage chamber, and starts the micro peristaltic system to put the blood system into the blood storage chamber; S2. Sampling Stage: When sampling is required, the user holds a negative pressure sample tube with a miniature puncture needle close to a specific skin location. The wireless controller 3 sends a command, and the control unit 18 first controls the added three-way valve to isolate the main flow line 13, and then activates a miniature actuator (such as a piezoelectric bender) above the blood storage chamber, causing a built-in fine needle to puncture the sealing membrane and inject the blood stored in the chamber into the sample tube. This design further reduces the risk of infection from repeated skin punctures over a long period of time.

[0044] Example 5: Implementation methods and variations of other key components This invention is not limited to the specific form described above; other feasible implementations are provided below: 1. Other options for the drive unit: The drive unit can be a miniature piston system driven by shape memory alloy (SMA). Specifically, the SMA spring contracts when heated by a 0.8A current, pushing the piston to generate negative pressure; after power is cut off and cooling occurs, it is reset by an auxiliary spring. Its structure is simple and produces no motor noise. 2. Anti-backflow design variant: In addition to duckbill valves, umbrella-shaped mechanical valves that open under negative pressure can also be used at the end of the main flow pipeline, or software logic can be added to the electric control valve to close by default when the system is powered off; 3. Communication and Power Transfer Variations: In addition to radio frequency methods, near-field inductive coupling can be used for power and command transmission. The wireless controller 3 can be designed as a patch worn on the body surface to achieve near-continuous communication and power supply; 4. Expanded monitoring functions: In addition to pressure sensors, optical sensors can be integrated into the flow path to detect bubbles or blood color, or miniature ultrasonic flow meters can be integrated to directly measure instantaneous flow, providing more feedback dimensions for the control unit.

[0045] The above embodiments are merely illustrative of the technical solutions of the present invention. Those skilled in the art, based on their understanding of the principles and spirit of the present invention, can make various substitutions and modifications to the components, parameters, and connection relationships without departing from the essence of the present invention. All such substitutions and modifications should fall within the protection scope defined by the claims of the present invention.

Claims

1. An implantable portal vein and its collateral vein blood taking system, characterized in that, The blood taking system comprises an implant unit, a driving unit, a control unit and a communication unit. The implant unit is provided with a blood flow path in communication with a portal vein or its branch vein, and can be completely implanted in the body. The driving unit is in communication with the blood flow path, and is used to generate negative pressure to drive blood flow. The control unit is used to control the working parameters of the driving unit. The communication unit is used to communicate wirelessly with an extracorporeal device. The control unit is configured to receive control instructions from outside the body through the communication unit, and accurately control the driving unit according to the instructions to extract a predetermined volume of portal vein and its branch vein blood sample.

2. The implantable portal and its tributary vein blood removal system according to claim 1, wherein, The blood flow path comprises a blood vessel interface for anastomosis with a blood vessel, a main flow path in communication with the blood vessel interface, and a sample output path for guiding the extracted blood to the outside of the body. The driving unit is arranged on the main flow path or the sample output path.

3. The implantable portal and its tributary vein blood removal system according to claim 2, wherein, The end of the sample output path is connected with a subcutaneous port that can be punctured transcutaneously. Alternatively, the system body unit is further provided with a blood storage cavity for temporarily storing the extracted blood.

4. The implantable portal and its tributary vein blood removal system according to any one of claims 1 to 3, characterized in that, The blood taking system further comprises a pressure sensor for monitoring the pressure in the blood flow path, and the pressure sensor is in signal connection with the control unit. The control unit is configured to adjust the working parameters of the driving unit or determine the abnormal state of the blood sampling process in real time according to the feedback signal of the pressure sensor.

5. The implantable portal and its tributary vein blood removal system according to any one of claims 1 to 3, characterized in that, The driving unit is one of a micro piezoelectric system, a micro peristaltic system or a micro piston system driven by a shape memory alloy.

6. The implantable portal and its tributary vein blood taking system according to claim 2 or 3, characterized in that, At least one one-way valve is further arranged on the blood flow path to prevent blood backflow and / or air entry.

7. The implantable portal and its tributary vein blood removal system according to claim 1, wherein, The communication unit is a radio frequency communication module, which is also used to receive wireless energy transmission from an extracorporeal device to power the driving unit and the control unit.

8. The implantable portal and its tributary vein blood removal system according to claim 1, wherein, The control unit is preconfigured with at least two different blood sampling programs associated with different negative pressure curves, blood sampling durations and / or target volumes.

9. A method of repeated blood sampling of the portal vein and its tributaries, characterized in that, The method using the implantable portal vein and its branch vein blood taking system according to any one of claims 1 to 8 comprises the following steps: S1: sending a control instruction containing blood sampling parameters to the communication unit of the blood taking system transcutaneously; S2: the control unit of the blood taking system drives the driving unit to generate an accurately controllable negative pressure according to the instruction; S3: under the action of the negative pressure, a predetermined volume of blood of the portal vein or its branch vein is extracted to a target position through the blood flow path.

10. The method of claim 9, wherein the blood is repeatedly sampled. In step S2 or after step S2, step S4 is further included: monitoring the blood sampling state through the pressure sensor arranged on the blood flow path, and feeding back the state data to the extracorporeal device through the communication unit; and / or when an abnormal pressure is monitored, automatically stopping blood sampling and sending an alarm information.

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