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CN-121987208-A - Non-invasive implanted wall-following deformation volume sensor

CN121987208ACN 121987208 ACN121987208 ACN 121987208ACN-121987208-A

Abstract

The invention provides a noninvasive implantable wall-following deformation volume sensor, which relates to the technical field of implantable biomedical sensors and comprises an elastically deformable closed annular substrate, a conductive coil arranged on the annular substrate, a capacitor forming an LC resonant circuit with the conductive coil, an elastic supporting structure arranged in the annular substrate and a biocompatible packaging layer covering the outer side. The sensor enables the annular matrix to generate controllable concave deformation under the pressure action of the inner wall of the organ by regulating and controlling the distribution proportion and mechanical rigidity of the supporting structure, thereby changing the geometric parameters of the conductive coil and causing the resonance frequency change, and realizing the detection of the volume change of the organ. In addition, the elastic support structure and the annular matrix form a connection mode which allows relative sliding, so that the sensor can be automatically unfolded by means of resilience force after compression and delivery. The invention can respond to the whole geometric deformation, and has simple structure and high mechanical compliance.

Inventors

  • WANG HONGBO
  • CHANG XINXIN
  • WANG JINXING
  • WANG YUEYANG

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. A noninvasive implantable wall-following deformation volume sensor is characterized by comprising a closed annular substrate capable of elastically deforming, a conductive coil arranged on the annular substrate, a capacitor forming an LC resonant circuit with the conductive coil, an elastic supporting structure arranged in the annular substrate and a biocompatible packaging layer covering the outer side, wherein the elastic supporting structure is used for limiting free radial expansion of the annular substrate, so that the annular substrate generates preset deformation under the action of external pressure, the geometric distribution of the conductive coil is changed, inductance parameter change is caused, detection of body cavity organ volume change is achieved, and the elastic supporting structure is arranged in a low-friction sleeve and forms a connecting structure allowing relative sliding with the annular substrate, so that the sensor can automatically recover to a preset unfolding form by means of resilience of the elastic supporting structure after being released in a compressed state.
  2. 2. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the annular matrix is made of a flexible elastic material.
  3. 3. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the elastic support structure comprises a shape memory alloy with elastic recovery capability.
  4. 4. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein no rigid fixed connection is formed between the elastic support structure and the annular base.
  5. 5. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the elastic support structure is disposed within the low friction sleeve to enable sliding movement relative to the annular base to provide an elastic spring back space after compression release, the elastic support structure being configured to define a deformation mode of the annular base to preferentially deform the annular base at spaced apart regions of the support structure.
  6. 6. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the sensor is maintained in a compressed state by a soluble coating material and automatically expands upon elastic support structure after dissolution release in a body fluid environment.
  7. 7. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the deformation comprises at least one of a circular-to-elliptical transition, a local concave deformation, a circumferential non-uniform compression.
  8. 8. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the inductance parameter variation is generated by a conductive coil geometry parameter variation caused by deformation of the annular base body, the resonance frequency is determined by sensor intrinsic parameters, and has low sensitivity to outcoupling distance variation.
  9. 9. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein the material of the encapsulation layer is medical silica gel, polyurethane or elastic polymer material.
  10. 10. The non-invasive implantable wall-following deformation volume sensor according to claim 1, wherein a change in resonance frequency of the sensor is detected by an external reading coil and organ volume information is obtained from the change in resonance frequency.

Description

Non-invasive implanted wall-following deformation volume sensor Technical Field The invention relates to the technical field of implantable biomedical sensors, in particular to a noninvasive implantable wall-following deformation volume sensor. Background Bladder volume changes are important physiological indicators for assessing lower urinary tract function. Bladder capacity perception is an important feedback mechanism to maintain normal urination control function, coordinating complex interactions between the peripheral nervous system and the brain. In clinical practice, intermittent catheterization is a gold standard for bladder emptying and volume estimation, but it is invasive in nature, often resulting in discomfort, psychological stress, and urinary tract infections. The existing in-vitro detection technology such as ultrasonic detection, bioelectrical impedance and near infrared method is difficult to realize long-term continuous monitoring. In recent years, researchers have proposed the use of flexible and stretchable electronics to construct bladder capacity monitoring schemes. 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 deformation of the bladder to estimate capacity. The proposal usually needs surgical implantation, generates body trauma, and has the problems of insufficient mechanical compliance, poor long-term stability, difficult local deformation to accurately reflect the whole volume change and the like. Thus, there is a need for a non-invasive implantable sensing structure that is capable of directly responding to the overall geometric deformation of an organ. Disclosure of Invention The invention aims to provide a noninvasive implantable wall-following deformation volume sensor which can be noninvasively implanted through a natural cavity and can synchronously deform along with the inner wall of an organ, and the noninvasive implantable wall-following deformation volume sensor comprises the following specific technical scheme: A noninvasive implantable wall-following deformation volume sensor comprises an elastically deformable closed annular substrate, a conductive coil arranged on the annular substrate, a capacitor forming an LC resonant circuit with the conductive coil, an elastic supporting structure arranged in the annular substrate, and a biocompatible packaging layer covering the outer side, wherein the elastic supporting structure is used for limiting free radial expansion of the annular substrate, so that the annular substrate generates preset deformation under the action of external pressure, the geometric distribution of the conductive coil is changed, inductance parameter change is caused, the detection of the volume change of a body cavity organ is realized, and the elastic supporting structure is arranged in a low-friction sleeve and forms a connecting structure allowing relative sliding with the annular substrate, so that the sensor can automatically recover to a preset unfolding form by means of the resilience of the elastic supporting structure after the sensor is released in a compressed state. The invention has the following beneficial effects: 1. The invention provides a volume sensing mode based on structure deformation modulation electromagnetic parameters, which realizes electromagnetic parameter measurement driven by structure form modulation. Different from the traditional scheme relying on local strain sensing or multipoint pressure detection, the invention realizes volume sensing by utilizing the shape change of the integral structure of the inductance coil, has the advantages of simple structure and no need of arranging a local strain measurement unit, has integral response capability to uneven loading and complex deformation, and has the advantages of improving measurement consistency and stability by designing and regulating a deformation mode through a supporting structure. 2. The invention provides a compressible non-invasive implantation and self-expanding integrated implantation type sensing structure. The structural design ensures that the supporting structure can rebound freely after being compressed, avoids the expansion failure caused by fixed friction, can be implanted into a body in a noninvasive manner, can realize in-situ expansion and function recovery without additional operation after implantation, and remarkably reduces implantation wounds and improves clinical operability. In conclusion, the passive volume monitoring sensor which has a simple structure, can be implanted noninvasively and is suitable for long-term in-vivo monitoring is realized through the cooperative design of the structural deformation sensing mechanism and the compressible self-expanding implantation mechanism. Drawings Fig. 1 is a schematic diagram of a non-invasive implantable wall-following deformation volume sensor and a non-inv