Self-powered controllable self-destructive intragastric air pressure monitoring microcapsule

Abstract

This invention discloses a self-powered, controllable, self-destructing microcapsule for monitoring intragastric pressure, belonging to the field of medical capsule technology. It aims to solve problems existing in current intragastric monitoring capsules, such as short power lifespan, uncontrollable gastric retention and expulsion, and bulky size and difficulty in swallowing due to modular design. The capsule includes a capsule shell, within which are sequentially arranged a retention unit, a circuit unit, and a primary battery unit. The retention unit ensures the capsule remains in the stomach, the circuit unit monitors intragastric pressure, and the primary battery unit supplies power to the circuit unit. This invention integrates self-powering, long battery life, controllable retention, and high miniaturization, providing a novel solution with significant clinical translational value for non-invasive, long-term, and safe monitoring of intragastric pressure.

Description

Technical Field

[0001] This invention relates to a self-powered, controllable, self-destructing microcapsule for monitoring intragastric pressure, belonging to the field of medical capsule technology. Background Technology

[0002] Intragastric pressure, as a core quantitative parameter for assessing gastric physiological energy supply, can directly reflect gastrointestinal motility and gastric emptying rate, and is of great significance in clinical scenarios such as the diagnosis and treatment of energy-dependent dyspepsia and postoperative evaluation of gastrointestinal surgery. Traditional nasal or oral catheter pressure measurement is an invasive method, which can easily cause patient discomfort and cannot be monitored continuously for a long time under natural physiological conditions.

[0003] While existing wireless swallowable capsules offer a non-invasive solution, they still face significant technical bottlenecks: firstly, the built-in battery has limited battery life, poses a risk of leakage, and restricts the miniaturization of the capsule; secondly, external radio frequency power supply is easily affected by gastric peristalsis and changes in body position, resulting in poor stability and making it difficult to meet the long-term monitoring needs of clinical practice. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a self-powered, controllable, self-destructing microcapsule for monitoring gastric pressure. This microcapsule integrates self-powering, long battery life, controllable retention, and high miniaturization, providing a novel solution with great clinical translational value for non-invasive, long-term, and safe monitoring of gastric pressure.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution: This invention provides a self-powered, controllable, self-destructing microcapsule for monitoring intragastric pressure, comprising a capsule shell, and inside the capsule shell are a retention unit, a circuit unit, and a primary battery unit arranged sequentially. The retention unit is used to retain the capsule in the stomach, the circuit unit is used to monitor intragastric pressure, and the primary battery unit is used to power the circuit unit.

[0006] Furthermore, the retention unit includes a retention unit shell, the surface of which has a retention unit through hole. The retention unit shell is filled with gastric retention type composite sodium alginate gelatin. TPU retention structures are inserted on both sides of the gastric retention type composite sodium alginate gelatin. The TPU retention structures extend to the outside of the retention unit shell and can unfold after the capsule shell is corroded by gastric juice and fall off after the gastric retention type composite sodium alginate gelatin is decomposed. The diameter of the unfolded TPU retention structure is larger than the pyloric diameter.

[0007] Furthermore, the gastric retention type composite sodium alginate gelatin adopts a gradient design, wherein it comprises, from near to far from the outer shell of the retention unit, composite sodium alginate gelatin cross-linked with calcium chloride and composite sodium alginate gelatin, and the preparation method of the composite sodium alginate gelatin includes: Based on 100 mL of compound sodium alginate gelatin, Take 60-70 mL of deionized water, add 1-1.2 g of sodium alginate, 0.8-1 g of type B gelatin, 1-2 g of edible glycerin and 1.5-2 g of sodium chloride in sequence, and add dilute hydrochloric acid to adjust the pH of the solution to 4-4.5. Stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution. Add deionized water to the homogeneous solution to bring the volume to 100 mL, and stir again until homogeneous to obtain composite sodium alginate gelatin.

[0008] Furthermore, the circuit unit includes a left circuit shell and a right circuit shell that are connected to each other, and the space formed by the left circuit shell and the right circuit shell is provided with a barometric pressure monitoring sensing circuit. The air pressure monitoring sensing circuit adopts a multi-layer circuit board stacking structure, which includes a boost voltage regulator module, a micro capacitor, an MCU main control unit, a Bluetooth module, and a pressure sensor. The boost voltage regulator module is used to boost the received primary battery power to the working voltage and transmit it to the micro capacitor. The micro capacitor is used to store the power and power the MCU main control unit, Bluetooth module, and pressure sensor. The right outer casing of the circuit is provided with a pressure measuring hole. The pressure sensor can monitor the intragastric hydraulic pressure through the pressure measuring hole and transmit the intragastric hydraulic pressure monitoring data to an external host computer through the Bluetooth module. The MCU main control unit is used to control the start and stop of the pressure sensor and the Bluetooth module according to the electrical energy stored in the micro capacitor.

[0009] Furthermore, the air pressure monitoring sensing circuit is integrally potted with electronic sealant; the surface of the pressure sensor is coated with a polyimide film to prevent corrosion by gastric juice; the left and right outer shells of the circuit are connected to each other by a tenon and mortise structure, and the connection is coated with medical waterproof and anti-corrosion adhesive.

[0010] Furthermore, the end of the outer shell of the retention unit near the left outer shell of the circuit is provided with a retention unit positioning plug, and the outer shell of the retention unit is inserted and connected to the left outer shell of the circuit through the retention unit positioning plug.

[0011] Furthermore, the primary battery unit includes a primary battery casing, the surface of which has a primary battery gastric fluid inlet hole. A zinc electrode is disposed inside the space formed by the primary battery casing and the right battery casing. A nylon filter and a hydrophilic PVDF sheet-like sodium alginate gel filling film are attached to the two sides of the zinc electrode from near to far. A copper electrode is disposed at the end of the primary battery casing away from the circuit unit. A wire hole is provided on the right battery casing. Both the zinc electrode and the copper electrode are connected to wires. The wires are connected to the boost voltage regulator module through the wire hole.

[0012] Furthermore, the preparation method of the hydrophilic PVDF sheet-like sodium alginate gel filler film includes: Based on a 25 mL hydrophilic PVDF sheet-like sodium alginate gel-filled membrane, Take 15-20 mL of deionized water, add 0.25-0.35 g of sodium alginate and 0.5-0.75 g of gelatin in sequence, and stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution; Add deionized water to the homogeneous solution to bring the volume to 25 mL, stir again until homogeneous, and solidify to obtain a hydrophilic PVDF sheet-like sodium alginate gel filler film.

[0013] Furthermore, the zinc electrode is mounted on the right outer casing of the circuit via a negative electrode support positioning post.

[0014] Furthermore, the outer shell of the retention unit, the left outer shell of the circuit, the right outer shell of the circuit, and the outer shell of the primary battery are all made of medical-grade polypropylene.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention is equipped with a retention unit, a circuit unit, and a primary battery unit, all of which are integrated into a high-density powder. This completely solves the problem of capsule volume redundancy while achieving a highly compact and miniaturized structure. The size is perfectly adapted to the human swallowing needs. The primary battery unit can provide self-power for the circuit unit. The retention unit perfectly balances the stable retention of the capsule in the stomach and its safe expulsion. The circuit unit enables effective monitoring of intragastric hydraulic pressure. This invention effectively suppresses self-reaction loss by modifying the surface of the zinc electrode, significantly extending the battery life while ensuring stable power output. It has extremely high practical value and broad application prospects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the explosion structure of a self-powered, controllable, self-destructing gastric pressure monitoring microcapsule in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a self-powered, controllable, self-destructing gastric pressure monitoring microcapsule in one embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of a self-powered, controllable, self-destructing gastric pressure monitoring microcapsule in one embodiment of the present invention; Figure 4 This is a schematic diagram of the zinc electrode structure of a self-powered, controllable, self-destructing gastric pressure monitoring microcapsule in one embodiment of the present invention; Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure along direction B; Figure 6This is a schematic diagram of the retention of a self-powered, controllable, self-destructing gastric pressure monitoring microcapsule in one embodiment of the present invention; In the diagram: 1-Capsule shell, 2-Retention unit shell, 3-Gastric retention type composite sodium alginate gelatin, 4-TPU retention structure, 5-Retention unit through hole, 6-Retention unit positioning rod, 7-Circuit left shell, 8-Tongue and tenon structure, 9-Gas pressure monitoring sensor circuit, 10-Pressure measuring hole, 11-Circuit right shell, 12-Wire hole, 13-Miniature mortise and tenon structure, 14-Negative electrode support positioning post, 15-Hydrophilic PVDF sheet sodium alginate gel filling membrane, 16-Nylon filter, 17-Zinc electrode, 18-Copper electrode, 19-Primary cell shell, 20-Primary cell gastric fluid inlet through hole, 21-Copper sheet positioning slot. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0018] like Figure 1 As shown, this embodiment of the invention provides a self-powered, controllable, self-destructing microcapsule for monitoring intragastric pressure, which includes a capsule shell 1 made of a material corrosive to gastric juice. The capsule shell 1 includes a retention unit, a circuit unit, and a primary battery unit arranged sequentially inside the capsule shell 1.

[0019] Combination Figure 2 and Figure 3 The retention unit is located at one end inside the capsule shell 1. It includes a retention unit shell 2. The top surface and side wall of the retention unit shell 2 are provided with through retention unit through holes 5, which not only realizes the connection between the internal microenvironment of the retention unit and the external environment of gastric juice in the stomach, but also serves as a dedicated channel for release into gastric juice during the self-destruction stage.

[0020] The outer shell 2 of the retention unit is filled with gastric retention-type composite sodium alginate gelatin 3. In some embodiments, to accelerate the self-destruction rate of the controlled self-destruction function, the gastric retention-type composite sodium alginate gelatin 3 adopts a gradient design. The outer layer in contact with the outer shell 2 of the retention unit is made of composite sodium alginate gelatin treated with calcium chloride crosslinking, while the rest is made of composite sodium alginate gelatin that has not been treated with calcium chloride crosslinking. The composite sodium alginate gelatin treated with calcium chloride crosslinking provides a good mechanical barrier, ensuring the sealing and retention stability of the capsule in the acidic environment of the stomach. The composite sodium alginate gelatin that has not been treated with calcium chloride crosslinking has a loose structure and high porosity, and can be rapidly dissolved and degraded in a neutral environment, thereby significantly shortening the self-destruction response time.

[0021] To ensure the system has stable and rapid pH-sensitive response characteristics, quantitative amounts of glycerol, sodium chloride powder, and dilute hydrochloric acid are added in precise proportions during preparation. After thorough mixing and homogenization, a stable composite gel system is formed.

[0022] Sodium alginate gelatin is a pH-sensitive material, exhibiting significant pH-responsive characteristics: in acidic environments, its microstructure shrinks, and the intermolecular forces strengthen, thus achieving structural stability; while in neutral environments, the network structure tends to loosen and gradually disintegrate. However, the decomposition rate of pure sodium alginate gelatin material is limited after transitioning from an acidic to a neutral environment.

[0023] Therefore, this embodiment modifies and optimizes the material. First, it uses type B gelatin particles, which, due to their negative charge in a neutral environment, generate electrostatic repulsion with sodium alginate molecules, effectively accelerating the overall swelling and disintegration rate of the material. Second, sodium chloride is introduced as a pore-forming agent during formulation. After the material is formed, the sodium chloride dissolves, creating a porous structure within the composite material, significantly improving the permeation rate and mass transfer efficiency of the external solution. Third, a measured amount of glycerol is added as a plasticizer, effectively improving the flexibility and mechanical strength of the composite material and optimizing its structural stability.

[0024] Specifically, the preparation method of compound sodium alginate gelatin includes the following steps: Based on 100mL of compound sodium alginate gelatin: Take 60-70 mL of deionized water, add 1-1.2 g of sodium alginate, 0.8-1 g of type B gelatin, 1-2 g of edible glycerin and 1.5-2 g of sodium chloride in sequence, and add dilute hydrochloric acid to adjust the pH of the solution to 4-4.5. Stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution. Add deionized water to the homogeneous solution to bring the volume to 100 mL, and stir again until homogeneous to obtain composite sodium alginate gelatin.

[0025] Both sides of the gastric retention composite sodium alginate gelatin 3 are fitted with TPU retention structures 4, which extend to the outside of the retention unit shell 2. The TPU retention structures 4 are rod-shaped structures created by 3D printing, and their surfaces undergo surface activation treatment using a plasma surface treatment machine. One end of the surface-activated TPU retention structure 4 is then uniformly coated with medical-grade food-grade silicone. After vacuum degassing of the gastric retention composite sodium alginate gelatin 3, it is allowed to stand until it becomes a semi-solid state. Then, the TPU retention structure 4 is slowly inserted into the gastric retention composite sodium alginate gelatin. The silicone coating helps improve the adhesion between the TPU retention structure 4 and the gastric retention composite sodium alginate gelatin 3. Once the gastric retention composite sodium alginate gelatin 3 has fully cured and solidified, the TPU retention structure 4 and the gastric retention composite sodium alginate gelatin 3 are integrated.

[0026] Subsequently, a low concentration of calcium chloride was added as a crosslinking agent to the surface of the gastric retention type composite sodium alginate gelatin 3, thus obtaining the composite sodium alginate gelatin treated with calcium chloride crosslinking. The network interpenetration of each component is achieved through ionic crosslinking reaction, which further improves the mechanical strength and structural stability of the overall structure.

[0027] The circuit unit includes a left circuit shell 7 and a right circuit shell 11 connected to each other by a tenon and mortise structure 8. The end of the retention unit shell 2 near the left circuit shell 7 is provided with a retention unit positioning plug 6. The retention unit shell 2 is inserted and connected to the left circuit shell 7 through the retention unit positioning plug 6.

[0028] The space formed by the left outer shell 7 and the right outer shell 11 of the circuit is equipped with a barometric pressure monitoring and sensing circuit 9. The barometric pressure monitoring and sensing circuit 9 adopts a multi-layer circuit board stacking method, which includes a boost voltage regulator module, a micro capacitor, an MCU main control unit, a Bluetooth module and a pressure sensor.

[0029] In some embodiments, the joint between the tenon and mortise structure 8 and the positioning rod 6 of the retention unit is coated with medical waterproof and anti-corrosion adhesive to ensure the sealing performance of the connection between the units and long-term resistance to gastric acid corrosion.

[0030] The air pressure monitoring sensing circuit 9 is integrally potted with electronic sealant, achieving comprehensive protection for the internal components. This effectively blocks gastric juice corrosion and resists external mechanical impact, forming a double sealing mechanism through the sealing of the housing seams and the potting of the circuit. Furthermore, the surface of the pressure sensor is coated with a polyimide film to prevent gastric juice corrosion, thus preventing the pressure sensor from being corroded by gastric juice without affecting its measurement accuracy.

[0031] The gas pressure monitoring and sensing circuit operates in a low-power mode. The boost and voltage regulation module boosts the received energy from the primary battery to the operating voltage and transmits it to a miniature capacitor. The miniature capacitor stores the energy and powers the MCU main control unit, Bluetooth module, and pressure sensor. A pressure measuring hole is located on the right side of the circuit casing. The sensitive element of the pressure sensor is connected to this hole, facilitating the monitoring of intragastric hydraulic pressure. The monitored hydraulic data is transmitted to an external host computer via the Bluetooth module. Since the gas pressure monitoring and sensing circuit in this embodiment is low-power, the role of the MCU main control unit is to control the start and stop of the pressure sensor and Bluetooth module. Specifically, when the energy stored in the miniature capacitor reaches a preset threshold, the MCU main control unit is activated. The MCU main control unit then sequentially controls the pressure sensor to collect intragastric pressure data through the measuring hole and controls the Bluetooth module to transmit the collected data to the external host computer.

[0032] The primary battery unit includes a primary battery casing 19, which is connected to the right circuit casing 11 via a micro tenon structure 13, and the connection is coated with waterproof and anti-corrosion adhesive. A gastric fluid inlet hole 20 is provided on the surface of the primary battery casing 19. A zinc electrode 17 is disposed within the space formed by the primary battery casing 19 and the right circuit casing 11. In this embodiment, the zinc electrode 17 is mounted on the right circuit casing 11 via a negative electrode support positioning post 14, aiming to increase the effective reaction contact area, thereby improving the open-circuit voltage and current output density.

[0033] Combination Figure 4 and Figure 5 To extend the working life of the primary battery and suppress the energy loss caused by the self-reaction of the zinc electrode 17, a nylon filter 16 and a hydrophilic PVDF sheet-like sodium alginate gel filling film 15 are attached to the two sides of the zinc electrode 17 from near to far.

[0034] The nylon filter 16 has a smaller surface area than the zinc electrode 17, serving as a microscopic channel for hydrogen gas venting and effectively guiding reaction byproducts. The hydrophilic PVDF sheet-like sodium alginate gel filler 15, after vacuum impregnation, has a larger surface area than the zinc electrode 17. The excess portion is edge-sealed with epoxy resin, and a vent hole of approximately 1 mm is provided. The zinc electrode 17 reacts with gastric acid to produce zinc ions and hydrogen gas; the vent hole allows the small amount of gas bubbles generated by the zinc electrode to escape smoothly, preventing gas accumulation from affecting the reaction interface.

[0035] This design ensures efficient ion transport in gastric juices while physically blocking direct contact between a large number of hydrogen ions and zinc electrode 17, significantly suppressing self-corrosion side reactions and extending battery service life.

[0036] The hydrophilic PVDF sheet-like sodium alginate gel filler membrane 15 differs from the aforementioned gastric retention type composite sodium alginate gel 3 in that it serves solely as an ion transport medium for gastric juice, effectively preventing direct contact between the zinc electrode 17 and the gastric juice while ensuring ion transport efficiency. However, both the gastric retention type composite sodium alginate gel 3 and the hydrophilic PVDF sheet-like sodium alginate gel filler membrane 15 are edible materials and pose no biological risk in the human stomach.

[0037] In this embodiment, the preparation method of the hydrophilic PVDF sheet-like sodium alginate gel filler film 15 includes: Based on a 25 mL hydrophilic PVDF sheet-like sodium alginate gelatin gel filling membrane: Take 15-20 mL of deionized water, add 0.25-0.35 g of sodium alginate and 0.5-0.75 g of gelatin in sequence, and stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution; Add deionized water to the homogeneous solution to bring the volume to 25 mL, stir again until homogeneous, and solidify to obtain a hydrophilic PVDF sheet-like sodium alginate gel filler film.

[0038] The end of the primary battery casing 19 away from the circuit unit is provided with a copper electrode 18 through a copper plate positioning slot 21. The right casing 11 of the circuit has a wire hole 12. Both the zinc electrode 17 and the copper electrode 18 are connected to wires. The wires are connected to the boost voltage regulator module through the wire hole 12.

[0039] In some embodiments, the retention unit housing 2, the left circuit housing 7, the right circuit housing 11, and the galvanic cell housing 19 are all made of medical-grade polypropylene. This material is inexpensive, widely applicable to 3D printing processes, and possesses excellent corrosion resistance, maintaining good structural strength in the complex environment of the stomach and ensuring stable operation of the device.

[0040] The working principle of this invention includes: Combination Figure 6 Apply pressure to press the TPU retention structure 4 around the outer periphery of the retention unit shell 2, and then put the capsule shell 1 on top, completing the assembly.

[0041] After assembly, the capsule is administered to the stomach. Gastric juices corrode the capsule shell 1, and then the TPU retention structure 4 unfolds. Since the stomach is acidic at this time, the gastric retention composite sodium alginate gelatin 3 is stable. The unfolded TPU retention structure 4 has an overall diameter larger than the pyloric diameter, preventing it from being expelled from the stomach and thus completing the retention process.

[0042] When the capsule needs to be expelled, a powder consisting of a fixed amount of sodium citrate, sodium bicarbonate, and a small amount of sodium hydroxide is taken as a self-destruct agent. The purpose of the sodium hydroxide and sodium bicarbonate powder is to adjust the pH in the stomach to make the stomach environment more neutral, while the sodium citrate powder forms a complex with the calcium chloride used for cross-linking, making the overall structure of the sodium alginate gelatin complex looser and easier to decompose.

[0043] After the gastric retention type of compound sodium alginate gelatin 3 material decomposes, the TPU retention structure 4 falls off. At this time, the overall size of the capsule is smaller than the diameter of the pylorus, so it will be expelled from the body over time. The TPU retention structure 4 scattered in the stomach will also be expelled because its size is much smaller than the diameter of the pylorus.

[0044] The monitoring data is periodically uploaded to the host computer via Bluetooth module. Since the signal directly monitored by the pressure sensor is the gastric fluid pressure, the host computer needs to first collect the average pressure under stable conditions, combine it with the local standard atmospheric pressure to complete zero-point calibration, and determine the fixed deviation value between the gastric fluid pressure and the gastric pressure. Then, the real-time data conversion is completed according to the formula: gastric pressure = real-time gastric fluid pressure - fixed deviation value. The data quality is optimized by means of timed recalibration, filtering and noise reduction, and outlier removal, so as to ensure that the host computer outputs an accurate and stable gastric pressure value, thereby realizing long-term, stable and efficient real-time monitoring of the gastric environment.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A self-powered, controllable, self-destructing microcapsule for monitoring intragastric pressure, characterized in that, The device includes a capsule shell, within which are arranged sequentially a retention unit, a circuit unit, and a primary battery unit. The retention unit is used to retain the capsule in the stomach, the circuit unit is used to monitor the hydraulic pressure in the stomach, and the primary battery unit is used to supply power to the circuit unit.

2. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 1, characterized in that, The retention unit includes a retention unit shell with a retention unit through hole on its surface. The retention unit shell is filled with gastric retention type composite sodium alginate gelatin. TPU retention structures are inserted on both sides of the gastric retention type composite sodium alginate gelatin. The TPU retention structures extend to the outside of the retention unit shell and can unfold after the capsule shell is corroded by gastric juice and fall off after the gastric retention type composite sodium alginate gelatin is decomposed. The diameter of the unfolded TPU retention structure is larger than the diameter of the pylorus.

3. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 2, characterized in that, The gastric retention type composite sodium alginate gelatin adopts a gradient design, in which it includes, from near to far from the outer shell of the retention unit, composite sodium alginate gelatin cross-linked with calcium chloride and composite sodium alginate gelatin. The preparation method of the composite sodium alginate gelatin includes: based on 100 mL of composite sodium alginate gelatin, Take 60-70 mL of deionized water, add 1-1.2 g of sodium alginate, 0.8-1 g of type B gelatin, 1-2 g of edible glycerin and 1.5-2 g of sodium chloride in sequence, and add dilute hydrochloric acid to adjust the pH of the solution to 4-4.

5. Stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution. Add deionized water to the homogeneous solution to bring the volume to 100 mL, and stir again until homogeneous to obtain composite sodium alginate gelatin.

4. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 2, characterized in that, The circuit unit includes a left circuit shell and a right circuit shell that are connected to each other. The space formed by the left circuit shell and the right circuit shell is equipped with a bar pressure monitoring and sensing circuit. The air pressure monitoring sensing circuit adopts a multi-layer circuit board stacking structure, which includes a boost voltage regulator module, a micro capacitor, an MCU main control unit, a Bluetooth module, and a pressure sensor. The boost voltage regulator module is used to boost the received primary battery power to the working voltage and transmit it to the micro capacitor. The micro capacitor is used to store the power and power the MCU main control unit, Bluetooth module, and pressure sensor. The right outer casing of the circuit is provided with a pressure measuring hole. The pressure sensor can monitor the intragastric hydraulic pressure through the pressure measuring hole and transmit the intragastric hydraulic pressure monitoring data to an external host computer through the Bluetooth module. The MCU main control unit is used to control the start and stop of the pressure sensor and the Bluetooth module according to the electrical energy stored in the micro capacitor.

5. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 4, characterized in that, The air pressure monitoring sensing circuit is integrally potted with electronic sealant; the surface of the pressure sensor is coated with a polyimide film to prevent corrosion by gastric juice; the left and right outer shells of the circuit are connected to each other by a tenon and mortise structure, and the connection is coated with medical waterproof and anti-corrosion adhesive.

6. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 4, characterized in that, The retention unit housing is provided with a retention unit positioning plug at one end near the left housing of the circuit, and the retention unit housing is inserted and connected to the left housing of the circuit through the retention unit positioning plug.

7. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 4, characterized in that, The primary battery unit includes a primary battery casing with a gastric fluid inlet hole on its surface. A zinc electrode is disposed within the space formed by the primary battery casing and the right outer casing. A nylon filter and a hydrophilic PVDF sheet-like sodium alginate gel filler are attached to the two sides of the zinc electrode from near to far. A copper electrode is disposed at the end of the primary battery casing away from the circuit unit. A wire hole is provided on the right outer casing of the circuit unit. Both the zinc electrode and the copper electrode are connected to wires, which are connected to the boost voltage regulator module through the wire hole.

8. The self-powered, controllable self-destructing gastric pressure monitoring microcapsule according to claim 7, characterized in that, The preparation method of the hydrophilic PVDF sheet-like sodium alginate gel filler film includes: Based on a 25 mL hydrophilic PVDF sheet-like sodium alginate gel-filled membrane, Take 15-20 mL of deionized water, add 0.25-0.35 g of sodium alginate and 0.5-0.75 g of gelatin in sequence, and stir at a constant temperature of 45-50℃ until completely dissolved to obtain a homogeneous solution; Add deionized water to the homogeneous solution to bring the volume to 25 mL, stir again until homogeneous, and solidify to obtain a hydrophilic PVDF sheet-like sodium alginate gel filler film.

9. The self-powered, controllable self-destructing gastric pressure monitoring microcapsule according to claim 7, characterized in that, The zinc electrode is mounted on the right outer casing of the circuit via a negative electrode support positioning post.

10. The self-powered, controllable, self-destructing gastric pressure monitoring microcapsule according to claim 7, characterized in that, The outer shell of the retention unit, the left outer shell of the circuit, the right outer shell of the circuit, and the outer shell of the primary battery are all made of medical-grade polypropylene.

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