A non-invasive implantable with-wall deformation volume sensor

Abstract

The application provides a non-invasive implantable wall deformation volume sensor, and relates to the technical field of implantable biomedical sensors, which comprises an elastically deformable closed ring-shaped base, a conductive coil arranged on the ring-shaped base, a capacitor forming an LC resonant circuit with the conductive coil, an elastic support structure arranged in the ring-shaped base, and a biocompatible encapsulation layer covering the outside. The sensor controls the distribution ratio and mechanical rigidity of the support structure, so that the ring-shaped base produces controllable concave deformation under the action of the pressure of the inner wall of an organ, thereby changing the geometric parameters of the conductive coil and causing the resonant frequency to change, and the detection of the volume change of the organ is realized. In addition, the elastic support structure and the ring-shaped base form a connection mode allowing relative sliding, so that the sensor can automatically expand by the elastic force after compression delivery. The application can respond to the overall geometric deformation, and has the advantages of simple structure and high mechanical compliance.

Description

Technical Field

[0001] This invention relates to the field of implantable biomedical sensor technology, and more particularly to a non-invasive implantable volumetric sensor that adapts to wall deformation. Background Technology

[0002] Bladder volume changes are an important physiological indicator for assessing lower urinary tract function. Bladder capacity perception is a crucial feedback mechanism for maintaining normal voiding control, coordinating complex interactions between the peripheral nervous system and the brain. In clinical practice, intermittent catheterization is the gold standard for bladder emptying and volume estimation, but its invasive nature often leads to discomfort, psychological stress, and urinary tract infections. Existing in vitro detection techniques such as ultrasound, bioelectrical impedance analysis, and near-infrared spectroscopy are insufficient for long-term continuous monitoring.

[0003] In recent years, researchers have proposed constructing bladder capacity monitoring solutions using flexible and stretchable electronic devices. Highly stretchable resistive and capacitive strain sensors have been developed using biocompatible silicone or hydrogel-based elastomers and attached to the bladder wall to measure local bladder deformation to estimate capacity. However, these solutions typically require surgical implantation, causing physical trauma, and suffer from problems such as insufficient mechanical compliance, poor long-term stability, and the inability of local deformation to accurately reflect overall volume changes.

[0004] Therefore, there is a need for a non-invasive implantable sensing structure that can directly respond to the overall geometric deformation of an organ. Summary of the Invention

[0005] The purpose of this invention is to provide a non-invasive implantable volumetric sensor that deforms with the organ wall, which can be non-invasively implanted through natural cavities and can deform synchronously with the inner wall of the organ. The specific technical solution is as follows:

[0006] A non-invasive implantable wall-deformable volumetric sensor includes: an elastically deformable closed annular substrate; a conductive coil disposed on the annular substrate; a capacitor forming an LC resonant circuit with the conductive coil; an elastic support structure disposed in the annular substrate; and a biocompatible encapsulation layer covering the outside. The elastic support structure restricts the free radial expansion of the annular substrate, causing the annular substrate to undergo a preset deformation under external pressure, thereby changing the geometric distribution of the conductive coil and causing changes in inductance parameters to detect changes in the volume of body cavity organs. Furthermore, the elastic support structure is disposed within a low-friction sleeve and forms a connection structure with the annular substrate that allows relative sliding, enabling the sensor to automatically return to a predetermined unfolded shape after being released from a compressed state, relying on the rebound force of the elastic support structure.

[0007] The present invention has the following beneficial effects:

[0008] 1. This invention proposes a volume sensing method based on structural deformation modulation of electromagnetic parameters, realizing electromagnetic parameter measurement driven by structural morphology modulation. Unlike traditional schemes that rely on local strain sensing or multi-point pressure detection, this invention utilizes the overall structural morphology change of an inductor coil to achieve volume sensing, offering advantages such as simple structure and no need for local strain measurement units; it also provides overall response capability to non-uniform loading and complex deformation; and the deformation mode can be designed and controlled through the support structure, improving measurement consistency and stability.

[0009] 2. This invention proposes an integrated implantable sensing structure that is compressible, non-invasively implantable, and self-deployable within the body. This structural design allows the support structure to spring back freely after compression, avoiding deployment failure due to fixed friction; the sensor can be non-invasively implanted; after implantation, in-situ deployment and functional recovery can be achieved without additional operation; significantly reducing implantation trauma and improving clinical operability.

[0010] In summary, this invention achieves a passive volume monitoring sensor that is simple in structure, non-invasively implantable, and suitable for long-term in vivo monitoring through the synergistic design of a structural deformation sensing mechanism and a compressible self-deploying implantation mechanism. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the non-invasive implantable wall-deformable volumetric sensor and the non-invasive implantation process according to an embodiment of the present invention.

[0012] Figure 2 This is a schematic diagram illustrating the core detection mechanism of the non-invasive implantable wall-deformable volumetric sensor according to an embodiment of the present invention.

[0013] Figure 3a This is a finite element simulation diagram of the volume monitoring sensor of this invention undergoing localized concave deformation under uniform pressure in the circumferential direction.

[0014] Figure 3b This is a diagram showing the relationship between coil inductance and indentation deformation in the sensor of this embodiment of the invention.

[0015] Figure 4 This is a schematic diagram illustrating the localized indentation deformation of the non-invasive implantable volumetric sensor that adapts to wall deformation according to an embodiment of the present invention.

[0016] Figure 5a This is a diagram of a force measurement device for a non-invasive implantable wall-deformation volumetric sensor according to an embodiment of the present invention, which undergoes elliptical deformation.

[0017] Figure 5b The graph shows the data of the restoring force after 1000 continuous cyclic tests with varying deformation.

[0018] Figure 6aThis is a schematic diagram of an external bladder simulated volume monitoring system according to an embodiment of the present invention.

[0019] Figure 6b To record the peak frequency shift and real-time volume of the implanted volume monitoring sensor during slow filling, rapid release, and cyclic filling-release of urine in an in vitro bladder volume monitoring system using physiological saline to simulate urine.

[0020] Figure 7a This is a record of the process of non-invasively implanting a sensor into an anesthetized miniature pig in an embodiment of the present invention.

[0021] Figure 7b The process of a sensor being delivered from the urethra to the bladder in the body, as recorded by DSA imaging.

[0022] Figure 8a In an embodiment of the present invention, DSA images were recorded showing the process by which the soluble material dissolved in the bladder after non-invasive implantation into anesthetized pigs, causing the sensor to self-deploy within the bladder cavity.

[0023] Figure 8b The sensor used for recording DSA images is attached to the inner wall of the bladder and undergoes corresponding indentation deformation as the volume of the bladder cavity changes.

[0024] Among them, 1 is the ring-shaped substrate, 2 is the conductive coil, 3 is the capacitor, 4 is the elastic support structure, 5 is the encapsulation layer, 6 is the medical filament, 7 is the soluble coating material, 8 is the catheter, 9 is the latex balloon, 10 is the water inlet, 11 is the implantable sensor unit, 12 is the acrylic container, 13 is the liquid medium, and 14 is the triaxial woven fabric reading coil. 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 and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0026] This invention provides a non-invasive implantable volumetric sensor that adapts to body wall deformation. An elastic support structure 4 guides a ring-shaped substrate 1 to generate controllable concave deformation, thereby modulating electromagnetic parameters and enabling the sensing of changes in the volume of body cavity organs. Figure 1As shown, it includes: a closed annular substrate 1 that can be elastically deformed; a conductive coil 2 disposed on the annular substrate 1; a capacitor 3 forming an LC resonant circuit with the conductive coil 2; an elastic support structure 4 disposed in the annular substrate 1; and a biocompatible encapsulation layer 5 covering the outside; the elastic support structure 4 is used to restrict the free radial expansion of the annular substrate 1, so that the annular substrate 1 produces a preset deformation under external pressure, including concave deformation or elliptical deformation, thereby changing the geometric distribution of the conductive coil 2 and causing changes in inductance parameters, so as to realize the detection of changes in the volume of body cavity organs; and the elastic support structure 4 is disposed in a low-friction sleeve and forms a connection structure with the annular substrate 1 that allows relative sliding, so that the sensor can automatically return to the predetermined unfolded shape by relying on the rebound force of the elastic support structure 4 after being released from the compressed state.

[0027] Preferably, the annular substrate 1 is made of a flexible elastic material.

[0028] Preferably, the elastic support structure 4 comprises a shape memory alloy with elastic recovery capability.

[0029] Preferably, the elastic support structure 4 and the annular base 1 do not form a rigid fixed connection.

[0030] Preferably, the elastic support structure 4 is disposed inside the low-friction sleeve, so that it can slide relative to the annular base 1, thereby providing elastic rebound space after compression and release. The elastic support structure 4 is used to limit the deformation mode of the annular base 1, so that the annular base 1 preferentially deforms in the interval area of ​​the elastic support structure 4.

[0031] Preferably, the sensor is kept in a compressed state by a soluble coating material 7, and automatically unfolds by an elastic support structure 4 after being dissolved and released in the body fluid environment.

[0032] Preferably, the deformation includes at least one of the following: transformation from a circular shape to an elliptical shape, local concave deformation, and circumferential non-uniform compression.

[0033] Preferably, the inductance change is generated by the change in coil geometric parameters caused by the deformation of the ring substrate 1, the resonant frequency is determined by the intrinsic parameters of the sensor, and it has low sensitivity to changes in external coupling distance.

[0034] Preferably, the encapsulation layer 5 is made of medical-grade silicone, polyurethane, or an elastic polymer material.

[0035] Preferably, the change in the resonant frequency of the sensor is detected by an external reading coil, and organ volume information is obtained based on the change in the resonant frequency.

[0036] The core measurement mechanism of a volume sensor of the present invention, which can be non-invasively implanted through natural cavities and can deform synchronously with the inner wall of organs, is as follows: Figure 2 As shown. This invention is achieved through the following technical solution:

[0037] Step 1) Preparation of a flexible ring matrix 1. A thin sheet-like ring matrix 1 is prepared by selecting a flexible polymer material with good biocompatibility and electrical insulation properties, and then fixed on a molding die to form a predetermined geometric structure.

[0038] In one embodiment, the annular substrate 1 may be made of polyetheretherketone (PEEK) film with a thickness of about 0.3 mm, a width of about 2.4 mm, and a diameter of about 100 mm.

[0039] Step 2) Constructing an LC resonant structure. A flexible conductive wire is tightly wound around the outside of the annular substrate 1 along the circumferential direction to form a miniature conductive coil 2; the two ends of the conductive wire are electrically connected to a miniature capacitor 3, thereby forming a passive LC resonant circuit.

[0040] In one embodiment, the conductor is a multi-strand polyurethane enameled copper wire, for example, formed by twisting together 8 strands of wire with a diameter of about 0.06 mm, with an overall outer diameter of about 0.25 mm; the capacitor 3 can be an NPO type chip capacitor with a 0402 package.

[0041] Step 3) Primary flexible encapsulation. The LC resonant structure wound on the annular substrate 1 is encapsulated for the first time using an encapsulation layer 5 with biocompatibility and waterproof properties, so as to form an annular strip-shaped microstructure suitable for adhering to the organ surface.

[0042] In one embodiment, the encapsulation material is a medical-grade silicone sealant, such as Wacker E41 medical silicone.

[0043] Step 4) Construct a low-friction elastic support structure 4. Select metal filaments with shape memory effect and superelasticity to construct the elastic support structure 4 inside the annular matrix 1. This structure provides a restoring force after the sensor is compressed and deformed, enabling it to return to the preset unfolded shape.

[0044] To ensure that the elastic support structure 4 can generate effective rebound during compression and release, and to avoid excessive frictional resistance caused by fixed constraints that would inhibit elastic recovery, the present invention sets the metal wire as a low-friction support structure that can slide relatively.

[0045] Specifically, a pre-bent metal filament is placed inside a smooth, thin-walled capillary tube, creating an isolation interface between the filament and the external structure. This reduces contact friction and provides radial and circumferential free sliding space for its elastic deformation.

[0046] In one embodiment, the metal filament is a nickel-titanium alloy wire with a diameter of approximately 0.4 mm. It is pre-bent to form a superior arc structure according to the diameter of the annular substrate 1, with a central angle greater than 180° and less than 360°. To further reduce interfacial frictional resistance, the surface of the metal filament can be lubricated or modified with a low-friction surface treatment. This allows the support structure to store elastic strain energy under compression and achieve stable rebound after the constraint is released. This results in an elastic support structure 4 with a smooth surface and low-friction slip characteristics.

[0047] In one embodiment, the capillary is a polyimide (PI) capillary with an inner diameter of approximately 0.5 mm and a wall thickness of approximately 0.03 mm.

[0048] Step 5) Flexible limiting installation of the support structure. The supporting arc formed in Step 4 is placed inside the annular strip structure obtained in Step 3 and fixed using a flexible limiting method, so that the support structure maintains relative sliding capability while its overall position is restricted. Finally, refer to Step 3 for encapsulation.

[0049] Specifically, medical filament 6 is selected to uniformly fix the supporting arc to the outside of the capillary in a spiral winding manner, so that the supporting structure is evenly distributed along the annular base 1, while avoiding direct compression of the metal filaments inside the capillary. Through the above structure, the spatial position of the elastic support structure 4 is limited, while the metal filaments can still slip slightly inside the capillary, thereby providing a stable elastic restoring force during compression and release.

[0050] In one embodiment, the medical suture 6 is a surgical suture with a diameter of approximately 0.2 mm, and the spiral winding pitch is uniformly set according to the sensor size. This ultimately forms an implantable volumetric sensor unit with controllable deformation and self-rebound capability.

[0051] Step 6) Non-invasive implantation and in vivo self-deployment. The implantable passive LC sensor has compressible properties and can be temporarily constrained by a soluble coating material 7 to reduce its overall volume, thus making it suitable for non-invasive delivery to the target body cavity via the catheter 8.

[0052] Specifically, after the sensor is folded and compressed to a predetermined shape, it is encapsulated and fixed with a soluble encapsulating material 7, keeping the sensor in a compressed state during delivery. The soluble encapsulating material 7 can gradually dissolve in a body fluid environment, thereby releasing the constraint on the sensor. After the soluble encapsulating material 7 dissolves, the elastic support structure 4 set inside the sensor releases the stored elastic strain energy, allowing the sensor to automatically return to the preset unfolded shape and complete in-situ release, achieving non-invasive implantation and reducing the risk of tissue damage.

[0053] In one embodiment, the implantable volume monitoring sensor unit can be folded and compressed along its annular structure, fixed together with the catheter 8 after being covered by a soluble coating material 7, and delivered through a natural body cavity to the target organ exemplified by the latex balloon 9.

[0054] In one embodiment, the sensor is delivered into the bladder cavity via the urethra through the catheter 8; after the soluble coating material 7 dissolves in the body fluid environment, the sensor automatically unfolds and releases due to the rebound force generated by the elastic support structure 4, and then the catheter 8 is withdrawn to complete the sensor implantation. The soluble coating material 7 may be a cold water-soluble polyvinyl alcohol (PVA) film or other biocompatible films with body fluid solubility.

[0055] The working principle of this invention is as follows:

[0056] The annular base 1 is made of a flexible material with a low Young's modulus, while the elastic support structure 4 is made of an elastic material with a higher Young's modulus, thus creating a non-uniform stiffness distribution within the same annular structure. When the elastic support structure 4 is flexibly connected to the annular base 1 via step 5), they together form an integrated annular elastic structure, wherein the elastic support structure 4 is arranged circumferentially along the annular base 1, and its corresponding central angle satisfies 180° < θ < 360°.

[0057] Due to the presence of the elastic support structure 4, the covered area forms a superior arc segment with higher stiffness, while the area without the elastic support structure 4 forms a inferior arc segment with lower stiffness, thus creating a predetermined structural stiffness difference in the circumferential direction. The plane containing the elastic support structure 4 is defined as the initial plane. The annular base 1 is a thin sheet structure, which has high resistance to bending perpendicular to the initial plane, and therefore tends to undergo in-plane deformation under external loads.

[0058] When the elastic support structure 4 is subjected to distributed radial centripetal compression, the inferior arc segment, due to its lower bending stiffness compared to the superior arc segment, preferentially undergoes inward concave deformation, which gradually deepens as the organ cavity contracts or external pressure increases. This "stiffness gap," formed by the stiffness difference, guides the structural deformation path, enabling the sensor to stably produce a predictable concave deformation pattern under circumferential compression conditions, rather than undergoing random deformation.

[0059] By adjusting the proportion and distribution range of the elastic support structure 4 in the circumferential direction of the annular matrix 1, the overall stiffness distribution and deformation mode of the structure can be controlled, thereby meeting the design requirements for deformation range and sensitivity in different application scenarios. This structural deformation mechanism enables the sensor to deform synchronously with the morphological changes of the organ's inner wall, rather than relying on local material strain, thereby improving the stability and consistency of volume monitoring.

[0060] Example 1: One embodiment of the present invention is as follows Figure 3aAs shown, when the sensor is subjected to uniform pressure in the circumferential direction, the annular structure undergoes localized indentation deformation. Finite element simulation analysis reveals that the adjustable stiffness notch in the sensor structure guides the deformation path, allowing the sensor to preferentially form a preset indentation deformation pattern under circumferential compression, thus achieving controllable deformation behavior. As the degree of indentation deformation increases, the effective area of ​​the annular coil changes. For example... Figure 3b As shown, the coil inductance decreases monotonically with increasing deformation. The simulation results and actual test results are consistent in their trend, verifying the feasibility and stability of inductance modulation through controllable structural deformation. The concave deformation process can be found in [reference needed]. Figure 4 As shown.

[0061] Example 2: Another embodiment of the present invention is as follows Figure 5a As shown in the figure. When the sensor is subjected to local pressure in the axial direction, the annular structure gradually transforms from an initial circular shape to an elliptical shape. Under the constraint of the elastic support structure 4, the sensor generates a restoring force opposite to the direction of deformation while deforming, thus ensuring that the structure can return to the predetermined shape after the external force is removed. Cyclic loading tests were performed on the sensor within a deformation range of 0-80mm, and the test results are shown in the figure. Figure 5b As shown, its maximum restoring force does not exceed 0.4 N. This result indicates that the sensor's restoring force is at a low level, and its self-deployment and deformation process in the body cavity environment is relatively mild, which can effectively reduce the risk of mechanical damage to body cavity organs and tissues, making it suitable for long-term in vivo working environments.

[0062] It should be understood that the above embodiments are only preferred embodiments of the present invention. Those skilled in the art can make various modifications or substitutions to its structural form, material selection and implementation without departing from the technical concept of the present invention. All such modifications or substitutions should fall within the protection scope of the present invention.

[0063] For example, but not limited to:

[0064] The annular base 1 is not limited to a circular structure, but can also be an ellipse, a polygon, or a closed curve structure that can undergo overall controllable deformation.

[0065] The elastic support structure 4 is not limited to nickel-titanium alloy material, but can also be made of metal material, polymer elastic material or composite elastic structure with elastic recovery capability;

[0066] The low-friction sleeve structure may be made of polyimide, fluorinated polymer, or other materials that can reduce interfacial friction and allow relative slippage.

[0067] The material of the encapsulation layer 5 is not limited to medical silicone, but can also be polyurethane, elastomer or other biocompatible polymer materials;

[0068] In addition to concave deformation and elliptic deformation, the deformation mode can also be circumferential non-uniform compression, local bending, or other restricted morphological changes that can cause changes in the electromagnetic parameters of the coil.

[0069] In addition to monitoring bladder volume, the sensor can also be applied to other scenarios involving the detection of changes in the volume of expandable body cavities or soft tissues.

[0070] Therefore, any technology that uses the concept of volume monitoring by modulating electromagnetic parameters through constrained structural deformation as described in this invention should be considered within the scope of protection of this invention.

[0071] Specific application 1: External bladder volume simulation monitoring system.

[0072] like Figure 6a As shown, an in vitro bladder simulation volume monitoring system was constructed to verify the performance of the sensor of the present invention. The system includes an acrylic container 12 for simulating the human abdominal cavity environment, a liquid medium 13 for simulating surrounding biological tissues, a latex balloon 9 for simulating the bladder, and a water inlet 10 for liquid injection and discharge, wherein the injection and discharge of physiological saline is used to simulate the process of urine volume change.

[0073] During the experiment, the implantable volume monitoring sensor of this invention was compressed into a narrow strip and then coated with a soluble material (PVA film, single layer thickness 25μm), and delivered into the interior of a latex balloon 9 through the water inlet 10. After the soluble coating material 7 dissolved, the sensor automatically unfolded based on the elastic support structure 4, forming a self-deploying implantable sensor unit 11. A triaxial woven fabric reading coil 14 was fixedly installed on the outside of the acrylic container 12 for electromagnetic coupling with the implantable sensor and for wirelessly measuring and recording electromagnetic parameters such as the sensor's resonant frequency. Figure 6b As shown, when the volume of the latex balloon 9 varies from 200 mL to 600 mL, the deformation of the sensor inside the balloon changes accordingly with the volume change, indicating that the sensor can respond to structural deformation caused by volume changes. Furthermore, during the slow filling, rapid release, and filling-release cycles of physiological saline, the changes in the resonant peak frequency and real-time volume data of the implantable volume monitoring sensor were recorded. The experimental results show that the sensor's resonant frequency exhibits a stable response relationship with volume changes, verifying the feasibility and repeatability of the sensor of this invention for continuous volume monitoring.

[0074] The in vitro simulation system in this embodiment is only used to verify the working principle of the present invention, and its structural form does not constitute a limitation on the application scenario of the present invention.

[0075] Specific application 2: Verification of non-invasive implantation in the bladder of anesthetized pigs.

[0076] like Figure 7a As shown, to verify the feasibility of in vivo delivery and operation of the implantable volume monitoring sensor of the present invention, a non-invasive implantation experiment was conducted in the bladder of anesthetized experimental pigs.

[0077] During implementation, the implantable volume monitoring sensor unit is folded and compressed along its annular structure to reduce its overall size, and temporarily fixed using a soluble encapsulating material 7 (PVA film, 25 μm thick per layer), keeping the sensor compressed and forming an integrated structure with the delivery catheter 8. Subsequently, the catheter 8 is non-invasively delivered into the bladder cavity via the urethra. The delivery process is recorded in real-time using DSA imaging, such as... Figure 7b As shown, sub Figures I-IV The delivery path of the sensor is shown as it enters from the urethra and gradually reaches the bladder cavity, demonstrating that the sensor can be implanted non-invasively through natural cavities.

[0078] Once the sensor enters the bladder, the soluble coating material 7 gradually dissolves in the body fluid environment. For example... Figure 8a , Figure 8b As shown, its child Figure I -III demonstrates the process by which the sensor automatically deploys within the bladder cavity using the restoring force of the elastic support structure 4. After the sensor is fully released, the delivery catheter 8 is withdrawn, thus completing the non-invasive implantation of the sensor. After implantation, as the bladder volume changes, it was observed that the sensor can conform to the bladder wall and exhibit varying degrees of indentation deformation with changes in bladder shape, indicating that the sensor can maintain a stable deployed state in the in vivo environment and produce a structural response to volume changes.

[0079] This embodiment is only used to illustrate the in vivo delivery and deployment method of the sensor of the present invention. The experimental subjects and implementation conditions do not constitute a limitation on the application scope of the present invention. The present invention is also applicable to other expandable body cavity environments.

[0080] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] The parts not disclosed in detail in this invention are known technologies in the field.

[0083] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, it should be understood that the invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of the present invention are protected.

Claims

1. A non-invasive implantable wall-adaptive volumetric sensor, characterized in that, include: A closed ring-shaped matrix that can be elastically deformed; A conductive coil disposed on the annular substrate; A capacitor that forms an LC resonant circuit with the conductive coil; An elastic support structure is disposed within the annular substrate; and a biocompatible encapsulation layer covers the outside; the elastic support structure is used to restrict the free radial expansion of the annular substrate, so that the annular substrate produces a preset deformation under external pressure, thereby changing the geometric distribution of the conductive coil and causing changes in inductance parameters, so as to realize the detection of changes in the volume of body cavity organs; and the elastic support structure is disposed within a low-friction sleeve and forms a connection structure with the annular substrate that allows relative sliding, so that the sensor can automatically return to the predetermined unfolded shape by relying on the rebound force of the elastic support structure after being released from the compressed state.

2. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The annular matrix is ​​made of a flexible elastic material.

3. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The elastic support structure includes a shape memory alloy with elastic recovery capability.

4. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The elastic support structure does not form a rigid fixed connection with the annular base.

5. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The elastic support structure is disposed within the low-friction sleeve, enabling it to slide relative to the annular base, thereby providing elastic rebound space after compression and release. The elastic support structure is used to limit the deformation mode of the annular base, so that the annular base deforms preferentially in the interval region of the support structure.

6. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The sensor is kept in a compressed state by a soluble coating material and automatically unfolds after being dissolved and released in the body fluid environment by an elastic support structure.

7. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The deformation includes at least one of the following: transformation from a circle to an ellipse, local concave deformation, and circumferential non-uniform compression.

8. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The change in inductance parameters is caused by the change in the geometric parameters of the conductive coil due to the deformation of the ring substrate. The resonant frequency is determined by the intrinsic parameters of the sensor and has low sensitivity to changes in the external coupling distance.

9. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The encapsulation layer is made of medical-grade silicone, polyurethane, or an elastic polymer material.

10. The non-invasive implantable wall-adaptive volumetric sensor according to claim 1, characterized in that, The change in the resonant frequency of the sensor is detected by an external reading coil, and organ volume information is obtained based on the change in the resonant frequency.

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