CN105997070B - A kind of contactless magnetic induction image system and its imaging method - Google Patents
A kind of contactless magnetic induction image system and its imaging method Download PDFInfo
- Publication number
- CN105997070B CN105997070B CN201610436598.8A CN201610436598A CN105997070B CN 105997070 B CN105997070 B CN 105997070B CN 201610436598 A CN201610436598 A CN 201610436598A CN 105997070 B CN105997070 B CN 105997070B
- Authority
- CN
- China
- Prior art keywords
- target organism
- signal
- magnetic field
- module
- coil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/0522—Magnetic induction tomography
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/40—Detecting, measuring or recording for evaluating the nervous system
- A61B5/4058—Detecting, measuring or recording for evaluating the nervous system for evaluating the central nervous system
- A61B5/4064—Evaluating the brain
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/42—Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems
- A61B5/4222—Evaluating particular parts, e.g. particular organs
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/43—Detecting, measuring or recording for evaluating the reproductive systems
- A61B5/4306—Detecting, measuring or recording for evaluating the reproductive systems for evaluating the female reproductive systems, e.g. gynaecological evaluations
- A61B5/4312—Breast evaluation or disorder diagnosis
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/48—Other medical applications
- A61B5/4887—Locating particular structures in or on the body
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7235—Details of waveform analysis
- A61B5/7253—Details of waveform analysis characterised by using transforms
- A61B5/7257—Details of waveform analysis characterised by using transforms using Fourier transforms
Abstract
The present invention relates to a kind of contactless magnetic induction image system and its imaging method, imaging system includes signal generating module, signal emission module, control module, signal receiving module, signal processing module, image display；Control module controls signal generating module and generates unifrequent radiofrequency signal, radiofrequency signal is applied in signal emission module in the form of alternating current, alternating current generates alternating magnetic field, signal receiving module receives alternating magnetic field, and the signal received is transmitted to signal processing module by control module, signal processing module is reconstructed the signal received to obtain the Two-Dimensional Reconstruction image of target organism, and Two-Dimensional Reconstruction image transmitting to image display is shown.Imaging method includes that excitation of electromagnetic wave, echo-signal measurement, the processing of target organism two-dimensional imaging and Two-Dimensional Reconstruction image are shown.
Description
Technical field
The invention belongs to magnetic induction image technical fields, and in particular to a kind of contactless magnetic induction image system and its at
Image space method.
Background technique
Currently, using the imaging means such as X-CT, MRI can the brain edema caused by cerebral hemorrhage, ischemic be imaged, still
X-CT there are radioactivity due to being not easy to be used for multiple times, and X-CT and MRI belong to large scale equipment, can not continuously make by hospital bed
With continuous, real-time monitoring can not be carried out to the development process of brain edema.Non-contact magnetic inductive imaging method is raw for brain etc.
The monitoring method of the distribution of conductivity variation at object position, it can be used to the detections of brain diseases.Contactless noninvasive triage
Survey method is the new method of medical domain.Mapping magnetic induction image method for arbitrary shape organism be at present both at home and abroad all
The new method that do not report.
Summary of the invention
In order to solve the above problems existing in the present technology, the present invention provides one kind can be suitable for arbitrary shape biology
The contactless magnetic induction image system and its imaging method that physical examination is surveyed.
In order to achieve the above object, the technical scheme adopted by the invention is as follows: a kind of contactless magnetic induction image system packet
Include signal generating module, signal emission module, control module, signal receiving module, signal processing module, image display；
The signal generating module includes radio-frequency signal generator and multi-way contral switching circuit board, the signal emission module, letter
Number receiving module, control module and multi-way contral switching circuit board are connect with the radio-frequency signal generator respectively, described more
Channel control switch circuit board is connect with signal receiving module；
The control module controls the signal generating module and generates unifrequent radiofrequency signal, and radiofrequency signal is with alternation electricity
The form of stream is applied in the signal emission module, and alternating current generates alternating magnetic field, and the signal receiving module is to alternation
Magnetic field is received, and the signal received is transmitted to the signal processing module, the signal by the control module
Processing module is reconstructed the signal received to obtain the Two-Dimensional Reconstruction image of target organism, and Two-Dimensional Reconstruction image transmitting is extremely
Described image display module is shown.
Further, the signal emission module and signal receiving module are realized by radio-frequency coil；The signal transmitting
Module is employed as the radio-frequency coil of excitation coil, and the radio-frequency coil quantity as excitation coil is NT, NTFor natural number and NT≥
1；The signal receiving module is employed as the radio-frequency coil of measuring coil, and the radio-frequency coil quantity as measuring coil is NR, NR
For natural number and NR≥3。
Further, the radio-frequency coil uses solenoid coil, Helmholtz coil, patch radio-frequency antenna or opening
Radiating guide.
Further, the quantity of the radio-frequency coil is 16, centered on target organism, 16 radio frequency lines
Corral is evenly arranged into square around target organism；Each radio-frequency coil had not only been used as excitation coil to generate magnetic field, but also conduct
Measuring coil detects the distribution of changes of magnetic field and conductivity within and around target organism.
Further, in the gap between target organism and the radio-frequency coil and between each radio-frequency coil
It is filled with medium.
Further, the position between the radio-frequency coil as excitation coil and the radio-frequency coil as measuring coil
Set relationship are as follows: be respectively positioned on the ipsilateral of target organism, be located at identical height or different height；Or it is parallel to each other；Or it overlaps；
Or it has a certain degree with target organism.
Further, the operating frequency range of the contactless magnetic induction image system is 1MHz-10MHz.
A kind of Non-contact Magnetic induction image forming method based on the imaging system comprising following steps:
S1, setting one include signal generating module, signal emission module, control module, signal receiving module, signal processing
The contactless magnetic induction image system of module and image display；Signal generating module include radio-frequency signal generator and and
Multi-way contral switching circuit board；Signal emission module is employed as the radio-frequency coil of excitation coil, and signal receiving module uses
Radio-frequency coil as measuring coil；
S2, excitation of electromagnetic wave；
It is electric to target organism application sinusoidal alternating that control module controls at least one excitation coil in signal emission module
Stream；The sinusoidal alternating current generates excitation field around target organism, and excitation field makes target organism generate vortex,
Vortex generates induced magnetic field and/or end of a performance magnetic field；
S3, echo-signal measurement；
Control module controls at least three measuring coils identical from target organism vertical range in signal receiving module
Detect the induced magnetic field from target organism and/or end of a performance magnetic field；The induced magnetic field and/or end of a performance magnetic field transmission detected is extremely
Signal processing module；
S4, signal processing module carry out two-dimensional imaging processing to the induced magnetic field and/or end of a performance magnetic field that receive, obtain mesh
Mark the two-dimensional image data of organism；
S5, target organism two dimensional image be transmitted to image display and shown.
Further, in the step S4, signal processing module carries out the induced magnetic field and/or end of a performance magnetic field that receive
The detailed process of two-dimensional imaging processing are as follows:
S41, target organism is modeled；
The non-linear observation model between the electromagnetic attributes of target organism and scatter echo is established, based on measuring coil
The characterization model arranged evenly for establishing description target organism internal structure；
Non-linear observation model includes fields inside effect model and target external field-effect model；
The description of fields inside effect model are as follows:
In formula (3), HincFor incident magnetic, the π of ω=2 f is work angular frequency, and f is the tranmitting frequency of signal, μ0For freedom
The magnetic conductivity in space, G are Green's function,For the position vector from field source point to fringe magnetic field,It is raw from field source point to target
The position vector of a bit, k in object0For the wave number of free space, JmFor magnetoelectricity current density, Jm=j ω μ0(μr- 1) H, μrFor mesh
Mark the magnetic conductivity of organism, JsFor induced current density, Js=j ω ε0(εr- 1) E, ε0For the dielectric constant of free space, εrFor
The dielectric constant of target organism, εr=ε 'r-jσ/ωε0, σ is the conductivity of target organism, ε 'rIt is opposite for target organism
The real part of dielectric constant, E are total electric field, the in-field E=+scattered field；
The description of external field effect model are as follows:
In formula (4),For the unit vector of any point in from field source point to field domain,
R is from field
The distance at any point in source point to scattered field.
S42, imaging is calculated；
Induced magnetic field received by least three measuring coils and/or end of a performance magnetic field are analyzed as follows:
Successively to induced magnetic field received by any two measuring coil in all measuring coils and/or end of a performance magnetic field
It is compared two-by-two；
Successively obtained according to the difference that compares two-by-two the amplitude for being able to reflect the distribution of target organism electromagnetic attributes and
The information of phase；
According to the electromagnetic attributes distributed intelligence being consecutively detected, using MATLAB platform or other computer languages from foundation
Non-linear observation model and description target organism internal structure characterization model in extract corresponding variation numerical value and song
Line, and according to the two dimensional image of variation numerical reconstruction target organism.
Further, in the step S42, the reconstruction of target organism two dimensional image the following steps are included:
(1) any two measuring coil in all measuring coils is calculatedComplex visibility function:
Wherein * indicates complex conjugate, and<>indicates average time, complex visibility function VvisibilityIt is measured comprising any two
CoilPhase delay and/or amplitude difference；
(2) complex visibility function for successively calculating any two measuring coil obtains the always multiple visible of all measuring coils
Function is spent, when measuring coil is NRWhen a, NRFor natural number and NR>=3, total complex visibility function is NR(NR- 1) a measuring coil
The sum of complex visibility function；
(3) by carrying out inverse Fourier transform to the total complex visibility function of all measuring coils, Arbitrary Target is obtained
The two dimensional image of organism.
Due to using the technology described above, the invention has the benefit that the contactless magnetic induction image system of the present invention
Module, signal emission module, control module, signal receiving module, signal processing module, image occurs by setting signal to show
Module generates alternating magnetic field using alternating current, and alternating magnetic field is received through spatial by signal receiving module, therefore the present invention
Non-contact, hurtless measure, without pasting any electrode on target organism, imaging method can be developed accordingly according to the present invention
Medical Instruments, can show corresponding curve, image, numerical value, can be to a variety of diseases such as tumour, diabetes, breast cancer etc.
It continuously monitors.
Detailed description of the invention
Fig. 1 is the schematic diagram of the contactless magnetic induction image system of the present invention；
Fig. 2 is the geometry arrangement schematic diagram of a pair of of radio-frequency coil in the contactless magnetic induction image system of the present invention；
Fig. 3 (a) is the two dimensional image of Three-dimensional model；Wherein, B1Indicate background, B2Indicate skin, B3Indicate muscle,
B4Indicate skull, B5Indicate cerebrospinal fluid, B6Indicate grey matter, B7Indicate white matter, B8Indicate endocranium, B9Indicate clot；
Fig. 3 (b) is the real part of the Two-Dimensional Reconstruction image of Three-dimensional model；
Fig. 3 (c) is the imaginary part of the Two-Dimensional Reconstruction image of Three-dimensional model；
Fig. 4 (a) is the two dimensional image of three-dimensional breast model；Wherein, C1Indicate background, C2Indicate skin, C3Indicate fat,
C4Indicate mammary gland, B5Indicate lesion；
Fig. 4 (b) is the real part of the Two-Dimensional Reconstruction image of three-dimensional breast model；
Fig. 4 (c) is the imaginary part of the Two-Dimensional Reconstruction image of three-dimensional breast model.
In figure: 1, signal generating module；2, signal emission module；3, control module；4, signal receiving module；5, at signal
Manage module；6, image display.
Specific embodiment
The electrical characteristics of biological tissue and the health status of physiological system are closely bound up, when the diseases such as breast cancer, leukaemia are sent out
When raw, significant changes occur for the dielectricity (common dielectric constant indicates) of biological tissue.The dielectricity of different type biological tissue
Difference is obvious, the dielectric constant of the high-moistures such as bone, tumour biological tissue biological tissue lower than water content such as fat
Dielectric constant is high, this difference provides feasible object for the physio-pathological condition that magnetic induction bio-imaging detects vivo biological tissue
Reason basis.The measurement that magnetic induction bio-imaging passes through magnetic distribution inside and around target organism under acting on excitation field
Image reconstruction is carried out, dielectric constant distribution, distribution of conductivity, Temperature Distribution and oxygen content of blood of certain biological tissues etc. are obtained
Important feature.Past 20 years, a large amount of work was all the application around magnetic induction technology in terms of bio-imaging and diagnosis
It carries out, such as brain imaging detection cerebral apoplexy and brain edema, breast imaging detection breast cancer and bone image checking osteoporosis.
The present invention will be described in detail with reference to the accompanying drawings and examples.
As shown in Figure 1, the present invention provides a kind of contactless magnetic induction image systems comprising signal generating module 1,
Signal emission module 2, control module 3, signal receiving module 4, signal processing module 5, image display 6.
Signal generating module 1 include radio-frequency signal generator and multi-way contral switching circuit board, signal emission module 2,
Signal receiving module 4, control module 3 and multi-way contral switching circuit board are connect with radio-frequency signal generator respectively, multichannel
Control switch circuit board is connect with signal receiving module 4.Control module 3 controls signal generating module 1 and generates unifrequent radio frequency
Signal, radiofrequency signal are applied in signal emission module 2 in the form of alternating current, and alternating current generates alternating magnetic field, signal
Receiving module 4 receives alternating magnetic field, and the signal received is transmitted to signal processing module 5 by control module 3,
Signal processing module 5 is reconstructed the signal received to obtain the Two-Dimensional Reconstruction image of target organism, Two-Dimensional Reconstruction image
Image display 6 is transmitted to be shown.
In above-described embodiment, radio-frequency signal generator uses Network Analyzer.Signal emission module 2 and signal receiving module
4 are realized by radio-frequency coil.Signal emission module 2 is employed as the radio-frequency coil of excitation coil, the radio frequency as excitation coil
Number of coils is NT, NTFor natural number and NT≥1.Radio-frequency coil as excitation coil can be arranged in arbitrary shape and respectively penetrate
The height of frequency coil spacing target organism is all the same.Signal receiving module 4 is employed as the radio-frequency coil of measuring coil, as survey
The radio-frequency coil quantity for measuring coil is NR, NRFor natural number and NR≥3.Radio-frequency coil as measuring coil, which can be arranged in, appoints
Distance or height of the shape and each radio-frequency coil of anticipating away from target organism are all the same.
In above-described embodiment, the quantity of radio-frequency coil is 16, and centered on target organism, 16 radio-frequency coils are surrounded
Target organism be evenly arranged into square.Each radio-frequency coil had not only been used as excitation coil to generate magnetic field, but also as measurement line
The distribution of changes of magnetic field and conductivity within and around circle detection target organism.
Further, to reduce signal coupling, detection sensitivity is improved, between target organism and radio-frequency coil and respectively
The media such as salt water are filled in gap between radio-frequency coil.
The working principle of the contactless magnetic induction image system of the present invention are as follows: apply alternation electricity in some excitation coil
Stream, alternating current generate alternating magnetic field, which reaches remaining all measuring coil through spatial.The propagation in magnetic field
By influenced by the conductivity and complex dielectric permittivity in space, the amplitude of the fringe magnetic field of more different measuring coils two-by-two
And phase difference, it will be able to obtain the information of space conductivity or complex dielectric permittivity or magnetic conductivity.Successively change excitation coil,
And measured respectively using remaining radio-frequency coil, one group of complete measurement data can be obtained.These measurement data are transmitted to
In signal processing module 5, signal processing module 5 carries out image reconstruction to the measurement data received, obtains two dimension to rebuild
Or the distributed image of three-dimension disclocation internal conductance rate or its variable quantity.Wherein, in measurement process, radio-frequency coil haves no need to change position
It sets.
In above-described embodiment, radio-frequency signal generator uses the Network Analyzer of model Keysight E5061B, can
To generate frequency range as the radiofrequency signal of 5Hz-3GHz.
In above-described embodiment, the working frequency of the contactless magnetic induction image system of the present invention is unifrequency, best work
Working frequency range is 1MHz-10MHz.
In above-described embodiment, radio-frequency coil uses solenoid coil, Helmholtz coil, patch radio-frequency antenna or open wave
The number of turns of lead antenna etc., radio-frequency coil is limited by working frequency and coil size.
In above-described embodiment, the radio-frequency coil as excitation coil and the position between the radio-frequency coil as measuring coil
Relationship are as follows: the radio-frequency coil as excitation coil is respectively positioned on the ipsilateral of target organism with the radio-frequency coil as measuring coil,
Positioned at identical height or different height；Or the radio-frequency coil as excitation coil is mutually put down with the radio-frequency coil as measuring coil
Row；Or the radio-frequency coil as excitation coil is overlapped with the radio frequency coil arrays as measuring coil；Or as excitation coil
Radio-frequency coil has a certain degree with target organism with the radio frequency coil arrays as measuring coil.
All radio-frequency coils as excitation coil are both needed to be distributed in identical height at spiral or non-homogeneous arbitrary shape, from
And form planar array.All radio-frequency coils as measuring coil are both needed in identical height into spiral or non-homogeneous arbitrary shape
Distribution, to form planar array.The distribution of radio-frequency coil as measuring coil can effectively improve detection sensitivity, reduction figure
As data obtaining time and installation cost.
Based on above-mentioned contactless magnetic induction image system, the present invention also provides a kind of contactless magnetic induction image sides
Method comprising following steps:
S1, setting one include signal generating module 1, signal emission module 2, control module 3, signal receiving module 4, signal
The contactless magnetic induction image system of processing module 5 and image display 6.Wherein, signal generating module 1 is believed including radio frequency
Number generator and with multi-way contral switching circuit board.Signal emission module 2 is employed as the radio-frequency coil of excitation coil, signal
Receiving module 4 is employed as the radio-frequency coil of measuring coil.
S2, excitation of electromagnetic wave；
At least one excitation coil applies sinusoidal alternating to target organism in the control signal emission module 2 of control module 3
Electric current；The sinusoidal alternating current generates excitation field around target organism, and under the action of electromagnetic induction, excitation field is logical
Vortex is generated when crossing target organism, vortex generates induced magnetic field and/or end of a performance magnetic field.
The above process further includes steps of
S21, the rectangular coordinate system for establishing target organism place region to be imaged, determine target organism and excitation coil
And the position coordinates and image points N of the distance of measuring coil, the position coordinates of excitation coil, measuring coil.
S22, apply sinusoidal alternating current from least one excitation coil to the target organism of arbitrary shape, which hands over
Time-dependent current generates excitation field around target organism, which can be considered as a time harmonic electromagnetic field, excitation
Vortex is generated because electromagnetic induction acts on when magnetic field passes through target organism.
Vortex is obtained by calculating magnetic potential vector A,
In formula (1), μ is magnetic conductivity, and ω is angular frequency, and the π of ω=2 f, f are the tranmitting frequency of signal, and σ is conductivity, JsFor
The current density of excitation coil.
S23, target organism or the N positioned at target organism one or both sides are surrounded onTA excitation coil successively emits
The electromagnetic wave of special frequency band, multiple measuring coils receive response magnetic field H (rr, ri, ω), wherein riFor the position of excitation coil
Coordinate, rrFor the position coordinates of measuring coil.
Further, if NT> 1, and when excitation coil is at Arbitrary distribution, successively each excitation coil is excited incident
, total in-field is NTThe sum of the in-field of a excitation coil excitation.
S24, target organism is removed into tested region, entering for identical reception position is measured under the premise of emission source is constant
Penetrate magnetic field Hinc(rr, ri, ω).
S25, target organism scattered field echo can be subtracted each other by the measurement data of step S23 and step S24 twice
It obtains, it may be assumed that
Hscat(rr, ri, ω) and=H (rr, ri, ω) and-Hinc(rr, ri, ω) and (2)
S3, echo-signal measurement；
Control module 3 controls at least three measurement lines identical from target organism vertical range in signal receiving module 4
Induced magnetic field and/or end of a performance magnetic field of the circle detection from target organism.The induced magnetic field and/or end of a performance magnetic field detected passes through
Local area network or serial ports are transmitted to signal processing module 5.
S4, signal processing module 5 carry out two-dimensional imaging processing to the induced magnetic field and/or end of a performance magnetic field that receive, obtain
The two-dimensional image data of target organism, detailed process are as follows:
S41, target organism is modeled；
It is non-linear between electromagnetic attributes and scatter echo to establish target organism dielectric constant, conductivity and magnetic conductivity etc.
Observation model, the foundation arranged evenly based on measuring coil describe the characterization model of target organism internal structure.
After penetrating target organism surface according to electromagnetic wave, Multiple Scattering between different tissues inside induction target organism
The mechanism of action obtains the fields inside effect model for describing non-linear observation model and target external field-effect model.
The description of fields inside effect model are as follows:
In formula (3), HincFor incident magnetic, the π of ω=2 f is work angular frequency, and f is the tranmitting frequency of signal, μ0For freedom
The magnetic conductivity in space, G are Green's function,For the position vector from field source point to fringe magnetic field,It is raw from field source point to target
The position vector of a bit, k in object0For the wave number of free space, JmFor magnetoelectricity current density, Jm=j ω μ0(μr- 1) H, μrFor mesh
Mark the magnetic conductivity of organism, JsFor induced current density, Js=j ω ε0(εr- 1) E, ε0For the dielectric constant of free space, εrFor
The dielectric constant of target organism, εr=ε 'r-jσ/ωε0, σ is the conductivity of target organism, ε 'rIt is opposite for target organism
The real part of dielectric constant, E are total electric field, the in-field E=+scattered field；
The description of external field effect model are as follows:
In formula (4),For the unit vector of any point in from field source point to field domain,
R is from field
The distance at any point in source point to scattered field.
When there is no magnetic medium or magnetic medium is negligible, i.e. μrWhen=1, the description of external field effect model
Are as follows:
When magnetic medium be can not ignore, i.e. μrWhen ≠ 1, the description of external field effect model are as follows:
Connecting inner field-effect model and external field effect model obtain non-linear observation model.
S42, imaging is calculated；
Induced magnetic field received by least three measuring coils and/or end of a performance magnetic field are analyzed as follows:
Successively to induced magnetic field received by any two measuring coil in all measuring coils and/or end of a performance magnetic field
It is compared two-by-two.
Successively obtained according to the difference that compares two-by-two the amplitude for being able to reflect the distribution of target organism electromagnetic attributes and
The information of phase.
According to the electromagnetic attributes distributed intelligence being consecutively detected, using MATLAB platform or other computer languages from foundation
Non-linear observation model and description target organism internal structure characterization model in extract corresponding variation numerical value and song
Line, and according to the two dimensional image of variation numerical reconstruction target organism.
The reconstruction of target organism two dimensional image the following steps are included:
(1) any two measuring coil in all measuring coils is calculatedComplex visibility function:
In formula (7), * indicates complex conjugate, and<>indicates average time, complex visibility function VvisibilityInclude any two
Measuring coilPhase delay and/or amplitude difference.
(2) complex visibility function for successively calculating any two measuring coil obtains the always multiple visible of all measuring coils
Function is spent, when measuring coil is NRWhen a, NRFor natural number and NR>=3, total complex visibility function is NR(NR- 1) a measuring coil
The sum of complex visibility function.
(3) by carrying out inverse Fourier transform to the total complex visibility function of all measuring coils, Arbitrary Target is obtained
The two dimensional image of organism.
The detailed process rebuild with reference to the accompanying drawing to target organism two dimensional image is illustrated.
As illustrated in fig. 2, it is assumed that certain point P (x, y, z) is located in target organism, point P (x, y, z) arrives radio-frequency coil area
Any two in domain are located atWithMeasuring coil scattering
Magnetic field complex visibility function is indicated with formula (7).
?The target strength of position are as follows:
The volume of the complex visibility function of target organism is divided into:
Formula (8) substitution formula (9) can be obtained:
In formula (10),λbFor the wavelength in medium,For spherical coordinates
Unit vector in systemDV=s2sinθdθdφds。
It defines new parameter (l, m, n):
DV can be obtained by following formula:
DV=s2dldmds/n (12)
Formula (12) are substituted into (10), are obtained:
Component of the basic lineal vector in cartesian coordinate systemFor
The complex visibility function equation of target organism becomes:
In formula (15),
If all radio-frequency coils are arranged in sustained height, radially the line integral of coordinate p are as follows:
Obtain following two-dimensional integration to the complex visibility function of variable (l, m) using formula (16):
Complex visibility function (17) is two-dimensional Fourier transform, and therefore, two dimensional image can pass through Fourier inversion weight
It builds:
Formula (18) shows that the two dimensional image of an objective object can answer visibility by inverse Fourier transform such as space
Function, which is rebuild, to be obtained.
S5, target organism two dimensional image be transmitted to image display 6 and shown.
In above-mentioned steps S2, Single frequency RF detectable signal is sent using at least one excitation coil, and utilize at least three
The induced magnetic field of measuring coil reception detectable signal, wherein at least three measuring coils and the spacing of target organism are each other
The identical and described spacing is greater than a wavelength of detection electromagnetic wave.
In above-mentioned steps S3, when target organism is non magnetic, conductive, target can be calculated by formula (5)
For organism in the fringe magnetic field of any one measuring coil, this method can be used for monitoring the brain edema, headstroke, glycosuria of organism
A variety of pathophysiologic features such as disease and burn.
When target organism had not only been magnetic but also is conductive, target organism can be calculated by formula (6) any one
The fringe magnetic field of a measuring coil, it is special that this method is applicable to a variety of physiological and pathologicals such as tumour and the mastocarcinoma of detection organism
Sign.
In above-mentioned steps S4, based on the received fringe magnetic field of at least two measuring coils institute at least three measuring coils
Come formed target organism at least one of electromagnetic attributes time series, and calculate what at least two measuring coils detected
The difference of electromagnetic attributes, to construct the two dimensional image of target organism.
Mutually the same method is kept according to the spacing of at least three measuring coil and target organism, is altered in steps
The spacing simultaneously synchronizes the difference for calculating the electromagnetic attributes that at least two measuring coils detect, to construct target organism
3-D image.
To verify Non-contact Magnetic induction image forming method proposed by the invention, three are established below by MATLAB platform
Simulation model is tieed up, for simulating the electromagnetic field effects of the difference organism when disease occurs.Fig. 3 (a) is Three-dimensional model
Two dimensional image, Fig. 3 (b) are the real parts of the Two-Dimensional Reconstruction image of Three-dimensional model, and Fig. 3 (c) is the two dimension of Three-dimensional model
The imaginary part of reconstructed image.Three-dimensional model reconstructed image can clearly display 8 kinds of different tissues of brain, wherein comprising going out
Hemorrhagic cerebral apoplexy.Fig. 4 (a) is the two dimensional image of three-dimensional breast model, and Fig. 4 (b) is the Two-Dimensional Reconstruction image of three-dimensional breast model
Real part, Fig. 4 (c) is the imaginary part of the Two-Dimensional Reconstruction image of three-dimensional breast model.The reconstructed image of three-dimensional breast model can be clear
Four kinds of different tissues of breast are shown clearly, wherein including tumour cell.
The present invention is not limited to above-mentioned preferred forms, and those skilled in the art can obtain under the inspiration of the present invention
Other various forms of products, however, make any variation in its shape or structure, it is all that there is same as the present application or phase
Approximate technical solution, is within the scope of the present invention.
Claims (2)
1. a kind of Non-contact Magnetic induction image forming method comprising following steps:
S1, setting one include signal generating module, signal emission module, control module, signal receiving module, signal processing module
With the contactless magnetic induction image system of image display；Signal generating module includes radio-frequency signal generator and and multi-pass
Road control switch circuit board；Signal emission module is employed as the radio-frequency coil of excitation coil, and signal receiving module is employed as
The radio-frequency coil of measuring coil；
S2, excitation of electromagnetic wave；
At least one excitation coil applies sinusoidal alternating current to target organism in control module control signal emission module；Institute
It states sinusoidal alternating current and generates excitation field around target organism, excitation field makes target organism generate vortex, vortex
Generate induced magnetic field and end of a performance magnetic field；
S3, echo-signal measurement；
Control module controls at least three measuring coil detection identical from target organism vertical range in signal receiving module
Induced magnetic field and end of a performance magnetic field from target organism；The induced magnetic field detected and end of a performance magnetic field transmission to signal processing mould
Block；
S4, signal processing module carry out two-dimensional imaging processing to the induced magnetic field and end of a performance magnetic field that receive, obtain target organism
The two-dimensional image data of body；
S5, target organism two dimensional image be transmitted to image display and shown；
In the step S4, signal processing module carries out the tool of two-dimensional imaging processing to the induced magnetic field and end of a performance magnetic field that receive
Body process are as follows:
S41, target organism is modeled；
Establish the non-linear observation model between the electromagnetic attributes of target organism and scatter echo, the distribution based on measuring coil
The characterization model of description target organism internal structure is established in arrangement；
Non-linear observation model includes fields inside effect model and target external field-effect model；
The description of fields inside effect model are as follows:
In formula (3), HincFor incident magnetic, the π of ω=2 f is work angular frequency, and f is the tranmitting frequency of signal, μ0For free space
Magnetic conductivity, G are Green's function,For the position vector from field source point to fringe magnetic field,For out of field source point to target organism body
The position vector of a bit, k0For the wave number of free space, JmFor magnetoelectricity current density, Jm=j ω μ0(μr- 1) H, μrFor target organism
The magnetic conductivity of body, JsFor induced current density, Js=j ω ε0(εr- 1) E, ε0For the dielectric constant of free space, εrIt is raw for target
The dielectric constant of object, εr=ε 'r-jσ/ωε0, σ is the conductivity of target organism, ε 'rIt is normal with respect to dielectric for target organism
Several real parts, E are total electric field, the in-field E=+scattered field；
The description of external field effect model are as follows:
In formula (4),For the unit vector of any point in from field source point to field domain,R is from field source point
The distance at any point in scattered field；
S42, imaging is calculated；
Induced magnetic field received by least three measuring coils and end of a performance magnetic field are analyzed as follows:
Two successively are carried out to induced magnetic field received by any two measuring coil in all measuring coils and end of a performance magnetic field
Two comparisons；
The amplitude and phase for being able to reflect the distribution of target organism electromagnetic attributes are successively obtained according to the difference compared two-by-two
Information；
According to the electromagnetic attributes distributed intelligence being consecutively detected, using MATLAB platform or other computer languages from the non-of foundation
Corresponding variation numerical value and curve are extracted in the characterization model of linear observation model and description target organism internal structure, and
According to the two dimensional image of variation numerical reconstruction target organism.
2. a kind of Non-contact Magnetic induction image forming method as described in claim 1, it is characterised in that: in the step S42, mesh
Mark organism two dimensional image reconstruction the following steps are included:
(1) any two measuring coil in all measuring coils is calculatedComplex visibility function
Wherein * indicates complex conjugate, and<>indicates average time, complex visibility function VvisibilityInclude any two measuring coilPhase delay and/or amplitude difference；
(2) complex visibility function for successively calculating any two measuring coil, obtain all measuring coils always answers visibility letter
Number, when measuring coil is NRWhen a, NRFor natural number and NR>=3, total complex visibility function is NR(NR- 1) a measuring coil is answered
The sum of visibility function；
(3) by carrying out inverse Fourier transform to the total complex visibility function of all measuring coils, Arbitrary Target biology is obtained
The two dimensional image of body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610436598.8A CN105997070B (en) | 2016-06-15 | 2016-06-15 | A kind of contactless magnetic induction image system and its imaging method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610436598.8A CN105997070B (en) | 2016-06-15 | 2016-06-15 | A kind of contactless magnetic induction image system and its imaging method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105997070A CN105997070A (en) | 2016-10-12 |
| CN105997070B true CN105997070B (en) | 2019-02-15 |
Family
ID=57089165
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610436598.8A Active CN105997070B (en) | 2016-06-15 | 2016-06-15 | A kind of contactless magnetic induction image system and its imaging method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105997070B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106725468B (en) * | 2016-11-22 | 2020-10-20 | 天津大学 | Multi-frequency electromagnetic tomography method for cerebral hemorrhage detection |
| CN109188431B (en) * | 2018-09-11 | 2021-04-02 | 合肥工业大学 | Holographic microwave fast imaging method based on compressed sensing |
| CN109199381B (en) * | 2018-09-11 | 2021-11-02 | 合肥工业大学 | Holographic microwave elastography system and imaging method thereof |
| CN110264534B (en) * | 2019-05-31 | 2023-03-24 | 西北大学 | Target imaging method and system based on RFID |
| CN110720914A (en) * | 2019-10-25 | 2020-01-24 | 深圳技术大学 | Sparse sampling-based holographic magnetic induction thoracic cavity imaging method and imaging system |
| CN110680319B (en) * | 2019-10-25 | 2020-08-14 | 深圳技术大学 | Magnetic induction molecular imaging method and system for biological tissue detection |
| CN110680320B (en) * | 2019-10-25 | 2020-11-06 | 深圳技术大学 | Magnetic induction imaging method and system |
| CN112345989A (en) * | 2020-11-18 | 2021-02-09 | 中国科学院电工研究所 | Magnetic characteristic imaging method for tumor tissue |
| CN116269302B (en) * | 2023-05-22 | 2023-08-11 | 杭州永川科技有限公司 | Magnetic induction tomography method, magnetic induction tomography device, computer equipment and storage medium |
| CN117547242A (en) * | 2024-01-12 | 2024-02-13 | 杭州永川科技有限公司 | Magnetic induction tomography apparatus |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100381096C (en) * | 2005-07-14 | 2008-04-16 | 中国人民解放军第四军医大学 | Non-contact magnetic inductive encephaledema monitoring method |
| WO2010003162A1 (en) * | 2008-07-11 | 2010-01-14 | Technische Universität Graz | Correction of phase error in magnetic induction tomography |
| JP2012501779A (en) * | 2008-09-11 | 2012-01-26 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Method and system for magnetically induced tomography |
| RU2534858C2 (en) * | 2009-03-30 | 2014-12-10 | Конинклейке Филипс Электроникс Н.В. | Magnetic induction tomography systems of coil configuration |
| EP2333587A1 (en) * | 2009-12-14 | 2011-06-15 | Technische Universität Graz | Device and method for magnetic induction tomography |
| CN102499682B (en) * | 2011-10-19 | 2013-08-07 | 中国人民解放军第四军医大学 | Excitation measuring multiplexing coil assembly for magnetic induction tomography and data collection |
-
2016
- 2016-06-15 CN CN201610436598.8A patent/CN105997070B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN105997070A (en) | 2016-10-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105997070B (en) | A kind of contactless magnetic induction image system and its imaging method | |
| CN100381096C (en) | Non-contact magnetic inductive encephaledema monitoring method | |
| Rodriguez-Duarte et al. | Experimental assessment of real-time brain stroke monitoring via a microwave imaging scanner | |
| CN109199381B (en) | Holographic microwave elastography system and imaging method thereof | |
| Ireland et al. | Feasibility study on microwave stroke detection using a realistic phantom and the FDTD method | |
| CN106108899B (en) | A kind of holography microwave imaging system and its imaging method | |
| CN106999089A (en) | Apparatus and method for analyzing body tissue layer in the electronic device | |
| Dachena et al. | Microwave imaging for the diagnosis of cervical diseases: A feasibility analysis | |
| WO2021077547A1 (en) | Method for magnetic induction molecular imaging used for biological tissue detection and system | |
| Hilger et al. | ultraMEDIS–ultra-wideband sensing in medicine | |
| Chen et al. | Combined planar magnetic induction tomography for local detection of intracranial hemorrhage | |
| Coşğun et al. | Microwave imaging of breast cancer with factorization method: SPIONs as contrast agent | |
| Ke et al. | A bio-impedance quantitative method based on magnetic induction tomography for intracranial hematoma | |
| Aldhaeebi et al. | Electrically small magnetic probe with PCA for near-field microwave breast tumors detection | |
| Guardiola et al. | Design and evaluation of an antenna applicator for a microwave colonoscopy system | |
| CN110680320B (en) | Magnetic induction imaging method and system | |
| Chen et al. | Intracranial hemorrhage detection by open MIT sensor array | |
| CN110960216B (en) | Multi-frequency holographic microwave brain imaging system and imaging method | |
| Bisio et al. | Brain stroke detection by microwave imaging systems: Preliminary two-dimensional numerical simulations | |
| AU2020103579A4 (en) | Magnetic induction imaging method and system thereof | |
| Rodriguez-Duarte et al. | Experimental validation of a microwave system for brain stroke 3-d imaging. diagnostics 2021 11 1232 | |
| Zhu et al. | Brain Injury Localization and Size Estimation using Electromagnetic Symmetric Crossing Lines Method | |
| Wang et al. | Microwave breast imaging techniques and measurement systems | |
| Cheng et al. | 3-D microwave imaging for breast cancer | |
| Wan et al. | The latest research status and prospect on microwave technology for monitoring concerned brain activity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |