Self-powered intragastric pressure monitoring capsule system

Abstract

This invention discloses a self-powered intragastric pressure monitoring capsule system, relating to the field of medical capsule technology. It comprises a negative electrode shell, a raised shell, and a concave shell arranged sequentially. A negative electrode unit is housed within the negative electrode cavity formed by the negative electrode shell and the raised shell. A circuit unit is housed within the circuit cavity formed by the raised shell and the concave shell. A positive electrode unit is located at the top of the concave shell. The negative electrode unit and the positive electrode unit together constitute a galvanic cell to power the circuit unit. This invention uses hydrochloric acid, abundant in gastric juice, as a natural electrolyte and combines it with biocompatible electrodes to construct a magnesium-copper galvanic cell system to achieve self-powering. It perfectly adapts to the dynamic environment within the stomach and maintains monitoring stability even during free movement.

Description

Technical Field

[0001] This invention relates to a self-powered gastric pressure monitoring capsule system, belonging to the field of medical capsule technology. Background Technology

[0002] Intragastric pressure is a key physiological parameter reflecting gastrointestinal motility, gastric emptying rate, and digestive tract patency. It has significant clinical value in the diagnosis of functional dyspepsia, postoperative functional assessment of gastrointestinal diseases, analysis of gastric motility disorders, and evaluation of drug efficacy. Traditional intragastric pressure monitoring mainly relies on nasal or oral catheters. This invasive method can easily cause irritation and discomfort to the throat and esophagus, and severely restricts patient activity, making long-term, continuous dynamic monitoring impossible under natural physiological conditions. To overcome these limitations, wireless capsule technology has emerged, but its power supply still faces serious challenges: built-in battery solutions pose a risk of electrolyte leakage and are difficult to miniaturize; external radio frequency coupling solutions are highly dependent on external devices and coupling posture, resulting in poor power supply stability. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a self-powered intragastric pressure monitoring capsule system. It uses hydrochloric acid, which is abundant in gastric juice, as a natural electrolyte and combines it with a biocompatible electrode to construct a magnesium-copper galvanic cell system to achieve self-powering. It can perfectly adapt to the dynamic environment inside the stomach and still ensure monitoring stability in a free-moving state.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution: This invention provides a self-powered intragastric pressure monitoring capsule system, comprising a negative electrode shell, a boss shell, and a concave shell arranged sequentially. A negative electrode unit is provided in the negative electrode cavity formed by the negative electrode shell and the boss shell. A multifunctional integrated sensing and control unit is provided in the circuit cavity formed by the boss shell and the concave shell. A positive electrode unit is provided on the top of the concave shell. The negative electrode unit and the positive electrode unit together constitute a primary battery to power the multifunctional integrated sensing and control unit.

[0005] Furthermore, the negative electrode unit includes a magnesium electrode, and an inner flange ring is provided on the inner side of the end of the negative electrode shell away from the boss shell. An anion exchange membrane is abutted on the side of the inner flange ring near the negative electrode chamber. The negative electrode chamber is filled with a mixed solution of magnesium chloride and acetic acid and a portion of sodium-type cation exchange resin. The boss housing has a boss on the side near the negative electrode shell. The boss extends into the negative electrode cavity. It has multiple vent holes evenly opened on the side wall of the negative electrode shell, and a breathable, water-proof, corrosion-resistant PTFE membrane is adhered between the vent holes.

[0006] Furthermore, the end of the protrusion near the negative electrode shell and the corresponding part of the negative electrode shell are provided with a matching snap-fit ​​structure. The snap-fit ​​structure is used to press the O-ring to achieve the sealing of the negative electrode chamber.

[0007] Furthermore, the multi-functional integrated sensing control unit adopts a multi-layer circuit board stacking structure, which includes a boost regulator module, a micro capacitor, an MCU control unit, a Bluetooth module, and a pressure sensor. The boost 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 control unit, Bluetooth module, and pressure sensor. The boss housing 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.

[0008] Furthermore, the circuit unit is encapsulated entirely with electronic sealant; the boss housing and the concave housing are connected by a tenon and mortise structure, and the connection is coated with medical waterproof and anti-corrosion adhesive.

[0009] Furthermore, the pressure measuring hole is filled with a biocompatible soft solid elastomer, which completely encapsulates the pressure sensor to achieve intragastric hydraulic pressure transmission while preventing gastric juice erosion.

[0010] Furthermore, the positive electrode unit includes a copper electrode, and a concave platform is provided at one end of the concave housing away from the convex housing. The copper electrode is disposed in the concave platform. Both the convex housing and the concave housing are provided with wire holes. The copper electrode and the magnesium electrode are connected to the boost and voltage regulator module through wires via the corresponding wire holes.

[0011] Furthermore, a rubber filter is provided on the side of the copper electrode away from the concave housing to prevent stomach residue from affecting the copper electrode.

[0012] Furthermore, the inside of each wire hole is filled with sealant.

[0013] Furthermore, the negative electrode shell, the boss shell, and the concave shell are all made of medical-grade polypropylene.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention uses hydrochloric acid, which is abundant in gastric juice, as a natural electrolyte and combines it with a biocompatible electrode to construct a magnesium-copper galvanic cell system to achieve self-powered operation. It does not require external electrolyte and completely avoids the biotoxicity risk of leakage from traditional batteries in principle. It achieves a high degree of compatibility and safe coexistence between energy self-supply and physiological environment. This invention features a dedicated low-power power management circuit that provides stable and continuous power support for the downstream miniature pressure sensor and wireless transmission module. Ultimately, through high-density integrated packaging technology, this invention achieves a miniaturized design of the monitoring device, enabling safe and long-term all-weather dynamic monitoring of intragastric pressure. This invention addresses the problem of self-corrosion of magnesium electrodes in strong acid environments. By introducing sodium-type cation exchange resin and acetate buffer into an independently encapsulated negative electrode chamber to regulate the local ionic environment, the self-corrosion effect of highly active magnesium electrodes is effectively suppressed by utilizing their ion exchange properties, significantly improving energy conversion efficiency and achieving more durable and stable energy output. This invention breaks through the space-consuming nature of traditional battery-powered architectures by adopting a high-density integrated package of self-powered modules and circuit systems to achieve a compact size suitable for swallowing. This design significantly reduces the foreign body sensation of subjects and can perfectly adapt to the dynamic environment inside the stomach, ensuring monitoring stability even in a free-movement state. Attached Figure Description

[0015] Figure 1 This is an exploded structural diagram of a self-powered intragastric pressure monitoring capsule system in one embodiment of the present invention; Figure 2 This is a schematic diagram of the external structure of a self-powered gastric pressure monitoring capsule system in one embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of a self-powered intragastric pressure monitoring capsule system in one embodiment of the present invention; Figure 4 This is a schematic diagram of the output characterization of the primary cell of a self-powered intragastric pressure monitoring capsule system in one embodiment of the present invention, wherein a is a schematic diagram of the open-circuit voltage curve of the primary cell and b is a schematic diagram of the short-circuit current curve of the primary cell. In the diagram: 1-Negative electrode shell, 2-Boss shell, 3-Negative electrode chamber, 4-Exhaust port, 5-Air-permeable, water-impermeable, corrosion-resistant PTFE membrane, 6-Magnesium electrode, 7-Wire hole, 8-Inner flange ring, 9-Anion exchange membrane, 10-O-ring seal, 11-Snap-fit ​​structure, 12-Circuit chamber, 13-Concave shell, 14-Tenon and tenon structure, 15-Multifunctional integrated sensing control unit, 16-Pressure measuring hole, 17-Positive electrode chamber, 18-Copper electrode, 19-Rubber filter. Detailed Implementation

[0016] 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.

[0017] like Figure 1As shown, this embodiment of the invention provides a self-powered intragastric pressure monitoring capsule system, comprising a negative electrode shell 1, a boss shell 2, and a concave shell 13 arranged sequentially.

[0018] Combination Figure 2 and Figure 3 The negative electrode shell 1 and the boss shell 2 together enclose the negative electrode chamber 3, which tightly seals the magnesium electrode 6, serving as the negative electrode unit. This design achieves physical isolation between the reactive magnesium material and the highly acidic gastric juice, effectively suppressing the self-corrosion side reaction from the source and significantly improving the battery's output efficiency and energy utilization.

[0019] The negative electrode shell 1 is generally annular, and an inner flange ring 8 is provided at the end away from the boss shell 2. The inner flange ring 8 abuts against the anion exchange membrane 9 on the side near the negative electrode chamber 3. The negative electrode chamber 3 is also filled with a certain concentration of magnesium chloride and acetic acid mixed solution and a small amount of sodium cation exchange resin. In this embodiment, to match the strong acid environment in the stomach, the pH value is 1, at which time the chloride ion concentration is about 0.1 mol / L, and the concentration of magnesium chloride solution is preferably 0.05 mol / L. The concentration of acetic acid is 0.2~0.4 mol / L. The amount of sodium cation exchange resin is positively correlated with the mass of magnesium. Preferably, the mass ratio of sodium cation exchange resin to magnesium is 10~18:1. Under the premise of meeting the miniaturized capsule volume limit, this ratio can maximize the absorption of reaction by-products and maintain the ion balance inside the battery.

[0020] A boss is provided on the side of the boss housing 2 near the negative electrode housing 1, extending into the negative electrode chamber 3. Vent holes 4 are correspondingly provided on the sidewalls of the negative electrode housing 1 and the boss. Multiple vent holes 4 are evenly distributed around the perimeter, and a breathable, water-impermeable, and corrosion-resistant PTFE membrane 5 is adhered between the vent holes 4 on the sidewalls of the negative electrode housing 1 and the boss. The breathable, water-impermeable, and corrosion-resistant PTFE membrane 5 can prevent the loss of internal electrolyte while releasing hydrogen gas.

[0021] In some embodiments, the end of the boss near the negative electrode housing 1 and the corresponding position of the negative electrode housing 1 are provided with a matching snap-fit ​​structure 11 and an O-ring seal 10. The snap-fit ​​structure 11 cooperates to press the O-ring seal 10 to form a sealed and stable connection to prevent the solution inside the negative electrode chamber 3 from leaking.

[0022] The concave housing 13 has a recessed platform at one end away from the protruding housing 2. A positive electrode unit is provided in the recessed platform. In this embodiment, the positive electrode unit includes a copper electrode 18. The copper electrode 18 and the magnesium electrode 6 form a primary cell to supply power to the multifunctional integrated sensing control unit 15.

[0023] In some embodiments, a rubber filter 19 is provided on the side of the copper electrode 18 away from the concave housing 13. The rubber filter 19 can isolate the copper electrode 18 from the external environment to block solid residues in the stomach and prevent solid residues in the stomach from adhering to the surface of the copper electrode 18 and reducing the effective reaction area.

[0024] The boss housing 2 and the concave housing 13 are connected by a tenon and mortise structure 14, and the connection is coated with medical-grade waterproof and anti-corrosion adhesive, such as NuSil MED-2000 waterproof and anti-corrosion adhesive. The circuit cavity formed by the fit between the boss housing 2 and the concave housing 13 houses a multi-functional integrated sensing control unit 15. The multi-functional integrated sensing control unit 15 adopts a multi-layer circuit board stacking structure, which includes a high-density integrated boost regulator module, a micro capacitor, an MCU control unit, a Bluetooth module, and a pressure sensor on a micro circuit board.

[0025] Both the boss housing 2 and the concave housing 13 are provided with wire holes 7. The copper electrode 18 and the magnesium electrode 6 are connected to the boost regulator module through the corresponding wire holes 7 via wires. In this embodiment, the boost regulator module uses an LTC1502 chip, which is used to boost the received power from the primary battery to a working voltage of about 3.3V and transmit it to a micro capacitor. The micro capacitor is used to store the power and power the MCU main control unit, Bluetooth module and pressure sensor, forming a low-power operating mode.

[0026] The boss housing 2 is provided with a pressure measuring hole 16, which is filled with a biocompatible soft solid elastomer with extremely low Shore hardness and high resilience. In some embodiments, this elastomer is medical liquid silicone, soft TPU, etc. The elastomer completely covers and seamlessly fits the pressure-sensitive surface of the pressure sensor, thereby blocking the direct erosion of gastric juice while achieving efficient and lossless transmission of hydraulic signals. The pressure sensor monitors the intragastric hydraulic pressure, and the monitored hydraulic data is transmitted to an external host computer via a Bluetooth module. Since the gas pressure monitoring sensing circuit in this embodiment is low-power, the role of the MCU main control unit in this process is to control the start and stop of the pressure sensor and the Bluetooth module. That is, when the electrical energy stored in the microcapacitor reaches a preset threshold, it triggers the MCU main control unit to wake up. The MCU main control unit then sequentially controls the pressure sensor to collect intragastric gas pressure data through the pressure measuring hole and controls the Bluetooth module to transmit the collected data to the external host computer.

[0027] To improve the sealing performance of the multi-functional integrated sensing main control unit 15, the multi-functional integrated sensing main control unit 15 is potted and protected using electronic sealant.

[0028] The working principle of this embodiment is as follows: When the capsule enters the stomach, the magnesium electrode 6 loses electrons to generate magnesium ions in the negative electrode chamber 3. At the same time, chloride ions in the external gastric juice permeate into the negative electrode chamber 3 through the anion exchange membrane 9 under the action of concentration difference and electric field to maintain charge balance.

[0029] To ensure efficient and continuous reaction, the negative electrode chamber 3 is filled with a mixed solution of magnesium chloride and acetic acid, as well as a small amount of sodium-type cation exchange resin. The cation exchange resin adsorbs the continuously generated magnesium ions through ion exchange, effectively preventing localized concentration polarization. The mixed solution of magnesium chloride and acetic acid stabilizes the chamber pH at approximately 5.8, inhibiting the formation of magnesium hydroxide precipitate and preventing the decrease in conductivity and current decay caused by precipitate adhering to the magnesium electrode surface, thus significantly extending battery life.

[0030] To address the gas generation issue during the reaction process, a one-way gas release channel is constructed by an air-permeable, water-impermeable, and corrosion-resistant PTFE membrane 5 adhered between the vent holes 4 on the side wall of the negative electrode shell 1 and the side wall of the boss. This not only prevents liquid leakage in the negative electrode chamber 3 but also promptly discharges the hydrogen generated by the reaction, eliminating the risk of internal pressure caused by gas accumulation.

[0031] The copper electrode 18 is directly exposed to the gastric fluid environment and forms a complete galvanic cell circuit with the magnesium electrode 6 through the anion exchange membrane 9.

[0032] In terms of energy management, the capsule can provide a stable open-circuit voltage of approximately 1.4V and a short-circuit current exceeding 2.5mA, such as... Figure 4 As shown. In order to convert this low-pressure, continuous chemical energy into standard electrical energy that can drive intelligent circuits, the system is designed with a multi-functional integrated sensing control unit 15, which is powered by the aforementioned primary battery.

[0033] The multi-functional integrated sensing control unit 15 utilizes the LTC1502 boost regulator chip to raise the 1.4V input voltage to the required system voltage level and solve the voltage matching problem. Simultaneously, a miniature capacitor acts as an energy buffer, collecting the continuous milliamp-level current generated by the primary battery to meet the instantaneous high power consumption demands of the wireless transmission module. This miniature capacitor continuously powers the MCU control unit and the MI-1B-48-010-BMAP miniature pressure sensor, and drives the low-power Bluetooth module to periodically transmit data to the host computer, enabling long-term monitoring of the gastric environment.

[0034] The pressure sensor has a measurement range of -300 to +500 mmHg, offering stable output and excellent accuracy, perfectly matching the needs of intragastric pressure monitoring. Considering the characteristic that the pressure sensor actually measures hydraulic pressure inside the stomach, after the sensor is inserted and stabilized, the host computer collects the average hydraulic pressure data of the gastric fluid, performs zero-point calibration by combining it with the local standard atmospheric pressure, calculates and saves the fixed deviation value between the hydraulic pressure and the intragastric gas pressure. Subsequently, the host computer continuously receives real-time hydraulic data, converts it using the formula "Intragastric Gas Pressure = Real-time Gastric Fluid Hydraulic Pressure - Fixed Deviation Value," and finally outputs a stable and accurate intragastric gas pressure value.

[0035] 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 capsule system for monitoring intragastric pressure, characterized in that, The device includes a negative electrode shell, a boss shell, and a concave shell arranged in sequence. A negative electrode unit is provided in the negative electrode cavity formed by the negative electrode shell and the boss shell. A multi-functional integrated sensing and control unit is provided in the circuit cavity formed by the boss shell and the concave shell. A positive electrode unit is provided on the top of the concave shell. The negative electrode unit and the positive electrode unit together constitute a primary battery to power the multi-functional integrated sensing and control unit. The negative electrode unit includes a magnesium electrode. An inner flange ring is provided on the inner side of the end of the negative electrode shell away from the boss shell. An anion exchange membrane is abutted on the side of the inner flange ring near the negative electrode chamber. The negative electrode chamber is filled with a mixed solution of magnesium chloride and acetic acid and a portion of sodium-type cation exchange resin. The boss housing has a boss on the side near the negative electrode shell. The boss extends into the negative electrode cavity. It has multiple exhaust holes evenly opened on the side wall of the negative electrode shell, and a breathable, water-proof, corrosion-resistant PTFE membrane is adhered between the exhaust holes. The end of the protrusion near the negative electrode shell is provided with a matching snap-fit ​​structure at the corresponding position of the negative electrode shell. The snap-fit ​​structure is used to press the O-ring to achieve the sealing of the negative electrode chamber.

2. The self-powered gastric pressure monitoring capsule system according to claim 1, characterized in that, The multi-functional integrated sensing control unit adopts a multi-layer circuit board stacking structure, which includes a boost regulator module, a micro capacitor, an MCU control unit, a Bluetooth module, and a pressure sensor. The boost regulator module is used to boost the received power from the primary battery to the working voltage and transmit it to the micro capacitor. The micro capacitor is used to store the power and power the MCU control unit, Bluetooth module, and pressure sensor. The boss housing 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.

3. The self-powered gastric pressure monitoring capsule system according to claim 2, characterized in that, The multifunctional integrated sensing control unit is encapsulated with electronic sealant; the boss housing and the concave housing are connected by a tenon and mortise structure, and the connection is coated with medical waterproof and anti-corrosion adhesive.

4. The self-powered gastric pressure monitoring capsule system according to claim 2, characterized in that, The pressure measuring hole is filled with a biocompatible soft solid elastomer, which completely encapsulates the pressure sensor to achieve intragastric hydraulic pressure transmission while preventing gastric juice erosion.

5. The self-powered gastric pressure monitoring capsule system according to claim 2, characterized in that, The positive electrode unit includes a copper electrode. A concave platform is provided at one end of the concave housing away from the convex housing. The copper electrode is located in the concave platform. Both the convex housing and the concave housing are provided with wire holes. The copper electrode and the magnesium electrode are connected to the boost and voltage regulator module through wires via the corresponding wire holes.

6. The self-powered gastric pressure monitoring capsule system according to claim 5, characterized in that, The copper electrode is provided with a rubber filter on the side away from the concave shell to prevent stomach residue from affecting the copper electrode.

7. The self-powered gastric pressure monitoring capsule system according to claim 5, characterized in that, The holes for the wires are all filled with sealant.

8. The self-powered gastric pressure monitoring capsule system according to claim 1, characterized in that, The negative electrode shell, the boss shell, and the concave shell are all made of medical-grade polypropylene.

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