CN-119112143-B - Passive human body cavity pressure measuring method and system based on multistable cell strings

CN119112143BCN 119112143 BCN119112143 BCN 119112143BCN-119112143-B

Abstract

The invention provides a passive human body cavity pressure measuring method and system based on a multistable cell string, which comprises the steps of receiving deformation data of the multistable cell string, wherein the multistable cell string generates deformation according to pressure change of a cavity to be measured, carrying out stress analysis on the deformation of the multistable cell string to obtain cell stress data, establishing a mapping relation between a deformation field and a pressure field based on the cell stress data, and carrying out pressure inversion on the deformation data of the multistable cell string according to the mapping relation to obtain the pressure data of the cavity to be measured. According to the invention, the deformation of the multistable cell strings can be used for responding to the pressure change in the human body cavity, then the calibration or conversion of the pressure data and the deformation data is carried out through the mapping relation between the deformation field and the pressure field, each pressure index after pressure measurement is obtained through rapid reading conversion, and the pressure measurement efficiency of the human body cavity is improved.

Inventors

CHEN ZEYANG
FANG JINGJING
LI YALUN
TAO ZHENHUI
YANG CHEN
DUAN CHENGYU
ZHAO ZEANG

Assignees

北京大学第一医院(北京大学第一临床医学院)

Dates

Publication Date: 20260512
Application Date: 20240902

Claims (6)

1. A passive human body cavity pressure measurement method based on a multistable cell string, comprising: S1, receiving deformation data of a multistable cell string, wherein the multistable cell string deforms according to pressure change of a cavity to be tested; s2, carrying out stress analysis on the deformation of the multistable cell strings to obtain cell stress data; In the stress analysis of the deformation of the multistable cell string in the step S2, the bending part of the single cell structure in the multistable cell string is simulated to be a fixedly supported Euler Bernoulli beam which is initially bent, and the unbent part of the single cell structure is assumed to be rigid; The expression of the control equation of the fixed support European Bernoulli beam is as follows: Wherein, the Is the modulus of young's modulus, Is the moment of inertia of the face of the beam, In the case of a differential operator, Is the transverse deflection of the beam, Is the pressure at which the pressure is applied, Is the span of the beam and, Is the initial shape of the beam and, In order to be the position of the beam, Is a dirac delta function that, A transverse force applied to the midpoint of the beam; The cell stress data is the compression force of the multistable cell string, and the expression of the compression force is as follows: Wherein, the In order to be able to compress the force, For the variation of the length of the beam, For the initial beam length, Is the cross-sectional area of the beam; S3, establishing a mapping relation between a deformation field and a pressure field based on the cell stress data; The expression of the deformation field in step S3 is: Wherein, the For the normalized deformation field, Is the modal index value of the multistable cell string, Is the first The mode coefficients of the individual modes, For the normalized pressure field of the liquid, Is the first The coefficients of the mode shape of the order, Compressive forces to which the normalized multistable cell string is subjected; The quadratic equation of the pressure field has the expression: Wherein, the Is the first coefficient of the quadratic equation of the pressure field, Is the second coefficient of the quadratic equation of the pressure field, Is the third coefficient of the quadratic equation of the pressure field, Is a coefficient of the first order mode shape, Is a coefficient of the third order mode shape, For the ratio of the height to the thickness of the curved beam, Is the modal defect size; And S4, performing pressure inversion on the deformation data of the multistable cell strings according to the mapping relation to obtain pressure data of the cavity to be detected.
2. The passive body cavity pressure measurement method based on multistable cell strings according to claim 1, wherein step S3 further comprises: S31, solving quadratic equations of the pressure field through a plurality of items of vectors of compressive forces born by the normalized multistable cell strings respectively to obtain a plurality of equation roots; s32, calculating a plurality of modal coefficient values and a plurality of deformation field values through a plurality of equation roots; And S33, drawing and obtaining the pressure field and a function curve of the deformation field according to the modal coefficient values and the deformation field values, and obtaining the mapping relation between the deformation field and the pressure field.
3. The passive human body cavity pressure measuring method based on the multistable cell string according to claim 2, wherein in the step S31, when solving the quadratic equation of the pressure field, a discriminant of the quadratic equation of the pressure field is analyzed, when the discriminant is smaller than 0, the quadratic equation of the pressure field is solved through the next term of the vector of the compressive force suffered by the normalized multistable cell string, and when the discriminant is larger than 0, the solution of the quadratic equation of the pressure field is output as an equation root.
4. The passive body cavity pressure measurement method based on the multistable cell string according to claim 2, wherein step S4 further comprises: s41, converting deformation data into pressure result data by a mapping relation; and S42, visually displaying the pressure result data.
5. A passive human body cavity pressure measurement system based on a multistable cell string, comprising: a multistable cell string, computing device; Wherein the multistable cell string is capable of deforming based on pressure changes of the cavity to be measured when placed in the cavity to be measured to generate deformation data, a processor in the computing device performs the steps S1-S4 of any one of claims 1 to 4, and calculates to obtain pressure data of the cavity to be measured.
6. The passive body cavity pressure measurement system based on multistable cell strings of claim 5, wherein the computing device specifically comprises: the deformation calibration module and the calculation module; the deformation calibration module is used for detecting deformation data of the multistable cell strings; the computing module further includes: The stress analysis unit is used for carrying out stress analysis on the deformation of the multistable cell strings to obtain cell stress data; The mapping relation establishing unit is used for establishing a mapping relation between a deformation field and a pressure field based on the cell stress data; And the pressure inversion unit is used for performing pressure inversion on the deformation data of the multistable cell strings according to the mapping relation to obtain the pressure data of the cavity to be detected.

Description

Passive human body cavity pressure measuring method and system based on multistable cell strings Technical Field The invention relates to the technical field of medical detection, in particular to a passive human body cavity pressure measuring method and system based on multistable cell strings. Background It is often necessary in the clinic to detect pressure within a body cavity (e.g., heart, chest, abdominal, bladder, rectal, anal canal, urethra, vagina, etc.) to complete diagnosis of a disease or assessment of organ function. For example, anorectal function assessment needs to be accomplished with the aid of an anorectal load cell. As another example, cystometry is performed to assess bladder function status, urethral manometry is performed to perform urodynamic analysis, and so forth. At present, researchers at home and abroad develop related research work in the aspect of human cavity pressure measuring devices, mainly concentrate on the aspect of sensor integration, lack practical research on portable devices, and do not meet the requirements of convenience and easiness in use in clinic. In the prior art, the existing pressure measuring method measures pressure through a pressure measuring device, cumbersome acquisition instrument hardware is required to acquire and decode a measured electric field, and complicated calculation and processing are required to be performed through professional software, so that measurement data cannot be intuitively obtained. A multistable cell is a special building block that is capable of exhibiting a variety of stable configurations under different external conditions or stimuli. This property makes the multi-stable cell of great application potential in various fields such as reconfigurable metamaterials, deformed structures, and energy absorbing structures. However, multistable cells are rarely used in clinical settings in the medical field, and the complexity of the body structure makes it necessary to recalculate and process the compression deformation of the multistable cells in order to obtain accurate data reflecting the pressure changes of the body organs or anatomical structures in a specific clinical setting. However, if the multistable cell is used in a specific clinical scenario, it is necessary to first design the corresponding pressure processing and analysis algorithm according to the characteristics of the clinical scenario, so as to further design the structure of the portable device suitable for the specific clinical scenario. Therefore, there is a need to develop a method for reflecting pressure changes in the body cavity by measuring and analyzing the deformation of the multistable cells, i.e., a passive body cavity pressure measurement method. Disclosure of Invention The invention provides a passive human body cavity pressure measuring method and system based on multistable cell strings, which are used for solving the defects of the prior art. The invention provides a passive human body cavity pressure measuring method based on multistable cell strings, which comprises the following steps: s1, receiving deformation data of a multistable cell string, wherein the multistable cell string deforms according to pressure change of a cavity to be tested; s2, carrying out stress analysis on the deformation of the multistable cell strings to obtain cell stress data; S3, establishing a mapping relation between a deformation field and a pressure field based on the cell stress data; And S4, performing pressure inversion on the deformation data of the multistable cell strings according to the mapping relation to obtain pressure data of the cavity to be detected. In the present invention, the multi-stable cell string is formed by connecting a plurality of multi-stable cells in series. The multistable cell may be a curved beam structure which deforms when subjected to a compressive force. In the invention, the human body cavity can be the natural cavity of the human body such as each cavity of the heart, the chest, the abdominal cavity, the bladder cavity, the urethra, the vagina, the rectal cavity, the anal canal and the like. According to the passive human body cavity pressure measuring method based on the multistable cell string, in the step S2, stress analysis is carried out on deformation of the multistable cell string, and the unbent part of the single cell structure is assumed to be rigid through simulating the bent part of the single cell structure in the multistable cell string as the initially bent solid support Euler' S beam. According to the passive human body cavity pressure measuring method based on the multistable cell strings, the expression of the control equation of the fixed support European Bernoulli beam is as follows: Wherein, the Is the modulus of young's modulus,Is the moment of inertia of the face of the beam,In the case of a differential operator,Is the transverse deflection of the beam,Is the pressure at which the pressure is applied,