CN102258371A - Device and method for detecting foreign matters in skin on basis of hollow-core sensor - Google Patents
Device and method for detecting foreign matters in skin on basis of hollow-core sensor Download PDFInfo
- Publication number
- CN102258371A CN102258371A CN2010105331089A CN201010533108A CN102258371A CN 102258371 A CN102258371 A CN 102258371A CN 2010105331089 A CN2010105331089 A CN 2010105331089A CN 201010533108 A CN201010533108 A CN 201010533108A CN 102258371 A CN102258371 A CN 102258371A
- Authority
- CN
- China
- Prior art keywords
- mrow
- msub
- alpha
- msup
- skin
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 17
- 230000005284 excitation Effects 0.000 claims abstract description 31
- 230000006698 induction Effects 0.000 claims abstract description 22
- 206010028980 Neoplasm Diseases 0.000 claims abstract description 15
- 230000037311 normal skin Effects 0.000 claims description 12
- 239000011159 matrix material Substances 0.000 claims description 11
- 238000005259 measurement Methods 0.000 claims description 7
- 230000035699 permeability Effects 0.000 claims description 6
- 238000004804 winding Methods 0.000 claims description 6
- 238000002940 Newton-Raphson method Methods 0.000 claims description 3
- 230000003321 amplification Effects 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 abstract 2
- 238000001514 detection method Methods 0.000 description 5
- 208000000453 Skin Neoplasms Diseases 0.000 description 2
- 201000011510 cancer Diseases 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 201000010099 disease Diseases 0.000 description 2
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 206010027476 Metastases Diseases 0.000 description 1
- 206010029098 Neoplasm skin Diseases 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 239000012811 non-conductive material Substances 0.000 description 1
- 206010033675 panniculitis Diseases 0.000 description 1
- 230000002062 proliferating effect Effects 0.000 description 1
- 210000004304 subcutaneous tissue Anatomy 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 210000001519 tissue Anatomy 0.000 description 1
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention belongs to the technical field of electromagnetic sensors and relates to device for detecting tumors or foreign matters in the skin on the basis of a hollow-core sensor. The device comprises the hollow-core sensor, a signal generation unit, a signal acquisition unit, a power amplifier and an upper computer, wherein the hollow-core sensor is a hollow-core coil and is vertically arranged on the position a certain distance above the skin to be detected; and the upper computer controls the current excitation signal generation unit to apply an exciting current signal on the hollow-core coil, and an induction signal unit is utilized for measuring an induction voltage of a phase which has a 90-degree phase difference with the phase of the applied exciting current signal. The invention provides the detecting method for realizing the detecting device simultaneously. The device and the method provided by the invention are more practical and convenient and the detecting device is one of the most-feasible tools for detecting the tumors or the foreign matters in the skin.
Description
Technical Field
The invention belongs to the technical field of electromagnetic sensors, and particularly relates to a device and a method for detecting tumors or foreign matters in skin.
Background
Skin tumors are cell proliferative diseases occurring in the skin, and are a common disease. There are many new species of organisms occurring in the intradermal or subcutaneous tissue, and there are clinically benign and malignant tumors. Malignant tumors can proliferate constantly, causing metastases, threatening life, and are called skin cancers.
Foreign bodies in the skin, such as pencil leads, needles, etc., are not only painful to touch, but also have undesirable reactions in the skin. Early discovery is required and removal is required.
Currently, the detection of tumors or foreign bodies in the skin is usually performed by using a skin detector. Skin monitors are expensive, somewhat bulky, and require contact with the skin for detection.
Disclosure of Invention
In view of the above-mentioned drawbacks and deficiencies of the prior art, it is an object of the present invention to provide a device for measuring tumors or foreign bodies in the skin using an electromagnetic method. The invention adopts the following technical scheme:
the device comprises an air-core sensor, a signal generating unit, a signal collecting unit, a power amplifier and an upper computer, wherein the air-core sensor is an air-core coil and is vertically placed above the skin to be detected for a certain distance, the upper computer controls a current excitation signal generating unit to apply an excitation current signal to the air-core coil, and an induction signal unit is used for measuring an induction voltage with a phase difference of 90 degrees with the applied excitation current signal.
In the detection device, the diameter of the air-core coil can be 5-100 mm. The number of winding turns of the coil is between 1 and 1000; the diameter of the winding is 0.01mm-10 mm.
The invention also provides a method for detecting tumors or foreign matters in skin based on the hollow sensor, which is realized by adopting the device and comprises the following steps:
(1) dividing the tissue in the skin into n layers, setting the initial conductivity σ of each layerγ＝σ1Lσn，
(2) The hollow sensor is arranged at a certain height from the normal skin, and the height l of the bottom of the coil is set1The height of the top of the coil is l2The number of turns of the coil is N, the inner and outer diameters are r1 and r2, and the inductance of the coil is L0Setting the excitation frequency of the air core sensor to be omega1LωmThe inductance value change amount at each of the different excitation frequencies is calculated according to the following equation:
U＝H2·H1·H0u is a 2 × 2 matrix, U12Number of first row and second column of the matrix, U22Is the number of the second row and the second column of the matrix,
wherein α is a spatial frequency variable; ω is the angular frequency of the excitation signal; u and H are transmission matrices; k is the amplification factor, J1(x) Is a first-order Bessel function of the first kind; z is a radical ofkIs the interface depth between the k and k +1 layers; sigmakDenotes the conductivity of the k layer, μkDenotes the permeability, μ, of the k layerk＝1；
(3) Calculating inductance values at the set excitation frequencies according to the inductance value variation;
(4) respectively applying excitation current I and excitation signals with the set excitation frequencies to the hollow-core sensor, collecting induction signal induction voltage U of the hollow-core sensor by a signal collection unit, sending the induction signal induction voltage U to an upper computer, and obtaining the measurement inductance value of the sensor through the induction voltage U and the excitation current I;
(5) seeking the value of the inductance of the sweep frequency in the least square sense to obtain the conductivity sigma of the normal skin1 /Lσn /And storing the data in a host computer as a calibration value;
(6) measuring the skin to be measured, repeating the steps (1) to (5), and measuring to obtain the conductivity of the skin to be measured;
(7) the upper computer sets a threshold value by comparing the conductivity of the skin to be detected with the conductivity of the normal skin, and when the difference value between the conductivity of the skin to be detected and the conductivity of the normal skin is larger than the threshold value, the upper computer can judge that the skin to be detected contains the components of the tumor or the foreign matters, otherwise, no foreign matters exist.
And (5) searching for the inductance value of the sweep frequency in the least square sense by utilizing a Newton-Raphson method.
The invention provides a non-contact method for detecting whether tumors or foreign bodies exist in the skin or not, and can detect in real time. Compared with the prior art, the method is more practical and convenient, and is one of the most feasible detection tools for tumors or foreign bodies in the skin.
Drawings
Fig. 1 is a block diagram of the structure of a device for detecting foreign matters in skin based on an air-core sensor.
Detailed description of the invention
The invention is further described in detail below with reference to the drawings and examples.
Fig. 1 is a block diagram showing the structure of a foreign body detecting device in skin based on an air-core sensor according to the present invention. The device consists of an air-core sensor (namely a coil in the figure, wherein the coil is an air-core coil), a signal generating unit, a signal acquisition unit, a power amplifier and an upper computer. The signal generating unit adopts a Direct Digital Synthesis (DDS) chip AD7008, which can generate sinusoidal excitation signals with different amplitudes and phases. The amplitude and phase of the exciting signal can be set by a computer and is amplified by a power amplifier and then is added on the exciting coil. And the computer controls a signal acquisition unit to acquire an induced voltage value of which the phase difference with the excitation current is 90 degrees for the coil.
The coil is formed by winding an insulated wire, the diameter of the winding is 0.01mm-10mm, the number of turns of the winding is 1-1000 turns, and the diameter of the coil is 5mm-100 mm. The bobbin is made of a non-conductive material, such as plastic or the like.
The skin is a layered structure and the detection of tumors or foreign bodies within the skin involves both positive and negative problems. Moving the coil to a certain height from the skin, firstly calibrating the normal skin, calculating the corresponding sweep frequency inductance value through the given conductivity (or permeability) distribution of the normal skin and a certain algorithm, namely the given conductivity (or permeability) distribution, and storing the sweep frequency inductance value in an upper computer as a calibration value, which is a positive problem; then measuring the skin to be measured, the upper computer controls the excitation signal sent by the signal generating unit to be connected to the coil 1 after passing through the power amplifier, the signal acquisition unit acquires the induction signal from the coil, the output of the induction signal is sent to the upper computer, the inductance value of the sensor can be obtained through the induction voltage and the excitation current, and the process of reconstructing the distribution of the conductivity (or the magnetic permeability) is reconstructed according to a certain algorithm, namely the frequency sweeping inductance value, which is the inverse problem.
The measuring method specifically comprises the following steps:
(1) the hollow sensor is arranged at a certain height from the normal skin, and the inductance value of the coil is set to be L0And setting the initial conductivity σγ＝σ1LσnAnd the measured coils, we can calculate a range of excitation frequencies ω according to algorithm (i)1LωmInductance value f (ω)1Lωm)＝ΔL+L0(ii) a The excitation signal sent by the upper computer control signal generating unit is connected to the coil 1 after passing through the power amplifier, the 4 signal acquisition unit acquires the induction signal from the hollow sensor, the output of the induction signal is sent to the upper computer, and the measured inductance value of the sensor is obtained through the induction voltage U and the excitation current I
The conductivity σ of normal skin can be obtained according to algorithm (ii)1 /Lσn /Stored in the host computer as calibration values for calibrating multiple types of skin, i.e. different sigma1 /Lσn /；
(2) Measuring the skin to be measured, and repeating the step (1) to obtain the conductivity of the skin to be measured;
(3) the upper computer sets a threshold value by comparing the conductivity of the skin to be detected with the conductivity of the normal skin, and when the difference value between the conductivity of the skin to be detected and the conductivity of the normal skin is larger than the threshold value, the upper computer can judge that the skin to be detected contains the components of the tumor or the foreign matters, otherwise, no foreign matters exist.
Positive problem algorithm (i):
for positive problem algorithms, see C.C.Cheng, C.V.Dodd, and W.E.Deeds, "General analysis of the product company structured controllers," int.J.Nondestruct.test., vol.3, pp.109-130, 1971.
The height of the bottom of the coil is indicated as 11 and the height of the top of the coil is indicated as 12. The number of turns of the coil is N, the inner and outer diameters are r1 and r2, and the height of the coil is L-12-11. Air-cored circular coil on the skin from skin layer conductivity σ1LσnThe induced inductance change is
Wherein,
U＝H2·H1·H0 (2)
u is a 2 × 2 matrix, U12Number of first row and second column of the matrix, U22Is the number of the second row and the second column of the matrix.
Wherein α is a spatial frequency variable; ω is the angular frequency of the excitation signal; u and H are transmission matrices; k is an amplification factor, J1(x) Is a first order bessel function. The depth of the interface between the k and k +1 layers is zk；σkDenotes the conductivity of the k layer, μkDenotes the permeability of the k-layer, where the measurement of the skin reveals μk＝1。
Inverse problem algorithm (ii):
the algorithm for inverse problem can be seen in-, "applied method of regularization method in the same problem of geological interpretation," izv. an. Sssr. fiz. zem., vol.1, pp.38-48, 1975. the problem-solving algorithm employed in the present invention is briefly described below.
The invention utilizes a Newton-Raphson method to seek the coincidence of the sweep inductance value under the least square meaning, which is a typical inverse problem solving method. Can be defined as:
(1)L0∈Rmis a vector expression of the measurement values of the swept frequency inductance at m frequencies;
(2)σ∈Rnis a conductivity distribution vector representation with n degrees of freedom;
(3)f：Rn→Rmis a function that maps the conductivity distribution to swept frequency inductance measurements;
(4)
is based on the squared difference of the calculated inductance measurement and the actual inductance measurement of the reconstructed conductivity distribution.
The inverse problem is to find sigma*So that phi is at least locally minimized. Differentiate φ from σ to make the result a vector of 0, i.e.:
φ′＝[f′]T[f-L0]＝0 (8)
f' is the additive ratio (Jacobian) matrix, which is an M N matrix defined as
Adopting a Tikhonov regularization method, wherein the given initial value vector of the conductivity is sigmaγAnd J is used to represent f (sigma)r) And then:
Δσ＝[JTJ+λ·diag(JTJ)]-1JT[f-L0] (10)
λ is the regularization parameter. Sigma*The estimate of (c) can be expressed as,
σ＝Δσ+σr
the above two equations can be iterated continuously until a suitable sigma is found*So that phi is at least locally minimized.
Claims (5)
1. The device comprises an air-core sensor, a signal generating unit, a signal collecting unit, a power amplifier and an upper computer, wherein the air-core sensor is an air-core coil and is vertically placed above the skin to be detected for a certain distance, the upper computer controls a current excitation signal generating unit to apply an excitation current signal to the air-core coil, and an induction signal unit is used for measuring an induction voltage with a phase difference of 90 degrees with the applied excitation current signal.
2. The hollow-core sensor-based device for detecting tumors or foreign bodies in skin according to claim 1, wherein the diameter of the hollow-core coil is 5-100 mm.
3. The hollow-core sensor-based device for detecting tumor or foreign body in skin according to claim 1, wherein the number of turns of the coil is between 1-1000; the diameter of the winding is 0.01mm-10 mm.
4. A method of detecting tumors or foreign bodies in the skin using the hollow-core sensor-based device of claim 1, comprising the steps of:
(1) dividing the tissue in the skin into n layers, setting the initial conductivity σ of each layerγ＝σ1Lσn，
(2) The hollow sensor is arranged at a certain height from the normal skin, and the height l of the bottom of the coil is set1The height of the top of the coil is l2The number of turns of the coil is N, the inner and outer diameters are r1 and r2, and the inductance of the coil is L0Setting the excitation frequency of the air core sensor to be omega1LωmThe inductance value change amount at each of the different excitation frequencies is calculated according to the following equation:
U＝H2·H1·H0u is a 2 × 2 matrix, U12Number of first row and second column of the matrix, U22Is the number of the second row and the second column of the matrix,
wherein α is a spatial frequency variable; ω is the angular frequency of the excitation signal; u and H are transmission matrices; k is the amplification factor, J1(x) Is a first-order Bessel function of the first kind; z is a radical ofkIs the interface depth between the k and k +1 layers; sigmakDenotes the conductivity of the k layer, μkDenotes the permeability, μ, of the k layerk＝1；
(3) Calculating inductance values at the set excitation frequencies according to the inductance value variation;
(4) respectively applying excitation current I and excitation signals with the set excitation frequencies to the hollow-core sensor, collecting induction signal induction voltage U of the hollow-core sensor by a signal collection unit, sending the induction signal induction voltage U to an upper computer, and obtaining the measurement inductance value of the sensor through the induction voltage U and the excitation current I;
(5) seeking the value of the inductance of the sweep frequency in the least square sense to obtain the conductivity sigma of the normal skin1 /Lσn /And storing the data in a host computer as a calibration value;
(6) measuring the skin to be measured, repeating the steps (1) to (5), and measuring to obtain the conductivity of the skin to be measured;
(7) the upper computer sets a threshold value by comparing the conductivity of the skin to be detected with the conductivity of the normal skin, and when the difference value between the conductivity of the skin to be detected and the conductivity of the normal skin is larger than the threshold value, the upper computer can judge that the skin to be detected contains the components of the tumor or the foreign matters, otherwise, no foreign matters exist.
5. The method of claim 4, wherein step (5) uses a Newton-Raphson method to find swept inductance values in the least squares sense.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105331089A CN102258371A (en) | 2010-11-05 | 2010-11-05 | Device and method for detecting foreign matters in skin on basis of hollow-core sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105331089A CN102258371A (en) | 2010-11-05 | 2010-11-05 | Device and method for detecting foreign matters in skin on basis of hollow-core sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102258371A true CN102258371A (en) | 2011-11-30 |
Family
ID=45005358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105331089A Pending CN102258371A (en) | 2010-11-05 | 2010-11-05 | Device and method for detecting foreign matters in skin on basis of hollow-core sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102258371A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105232042A (en) * | 2014-07-07 | 2016-01-13 | 北京大学深圳研究生院 | Detecting device and detecting system for electrical characteristics of human body surface |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999007281A1 (en) * | 1996-10-01 | 1999-02-18 | Reining International Ltd. | Conductance measuring apparatus |
| CN1728966A (en) * | 2002-12-19 | 2006-02-01 | 皇家飞利浦电子股份有限公司 | Fabric-integrated conductivity sensor |
| CN101832751A (en) * | 2010-06-08 | 2010-09-15 | 天津大学 | Device and method for measuring decarburization thickness of steel based on hollow-core sensor |
| CN101840002A (en) * | 2010-06-10 | 2010-09-22 | 尹武良 | Detection device and method for suspect metal object in shoe based on electromagnetic sensor |
-
2010
- 2010-11-05 CN CN2010105331089A patent/CN102258371A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999007281A1 (en) * | 1996-10-01 | 1999-02-18 | Reining International Ltd. | Conductance measuring apparatus |
| CN1728966A (en) * | 2002-12-19 | 2006-02-01 | 皇家飞利浦电子股份有限公司 | Fabric-integrated conductivity sensor |
| CN101832751A (en) * | 2010-06-08 | 2010-09-15 | 天津大学 | Device and method for measuring decarburization thickness of steel based on hollow-core sensor |
| CN101840002A (en) * | 2010-06-10 | 2010-09-22 | 尹武良 | Detection device and method for suspect metal object in shoe based on electromagnetic sensor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105232042A (en) * | 2014-07-07 | 2016-01-13 | 北京大学深圳研究生院 | Detecting device and detecting system for electrical characteristics of human body surface |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103156581B (en) | In vivo temperature measuring method and system based on alternating magnetization intensity of magnetic nanoparticles | |
| CN103892809B (en) | A kind of magnetic nano temperature formation method and system | |
| CN101788260B (en) | Eddy current measuring method of thickness of metal film | |
| CN103257182B (en) | A kind of impulse eddy current defect quantitative detection method and detection system | |
| EP3393335B1 (en) | Apparatus and methods for determining electrical conductivity of tissue | |
| JP2016524138A (en) | Apparatus and method for measuring electromagnetic characteristics | |
| CN102707323B (en) | Controllable source audio-frequency magnetic field sounding method for geological exploration | |
| CN101650211B (en) | Method and device for measuring conductive liquid level and conductivity based on double coils | |
| CN104280782B (en) | One-dimensional joint inversion method for time-frequency electromagnetic data and magnetotelluric data | |
| CN105044792A (en) | Ground-well time-frequency electromagnetic exploration data acquisition apparatus and method | |
| CN102508308A (en) | Transient electromagnetic multipoint array-type detection method of tunnel | |
| CN106442631A (en) | Layered interface rebuilding method based on electricity/ultrasonic bimodal fusion | |
| CN110133727A (en) | Ultra-deep oil and gas reservoir high-precision electromagnetism spectrum detection method | |
| CN100443889C (en) | Measurement system of specific absorption rate | |
| CN103006185B (en) | Device and method for non-contact magnetic induction impedance plane projection imaging | |
| CN104013388A (en) | Magneto-acoustic coupling imaging excitation and detection method and device based on low-frequency continuous waves | |
| CN103323883A (en) | Near-field magnetic dipole source high-density geometric resistivity sounding method | |
| CN110967767A (en) | Method for detecting karst cave by cross-hole induced polarization | |
| CN102258371A (en) | Device and method for detecting foreign matters in skin on basis of hollow-core sensor | |
| CN104434100B (en) | A kind of resistivity method for reconstructing of magnetic thermal acoustic imaging | |
| Goharian et al. | A trust region subproblem for 3D electrical impedance tomography inverse problem using experimental data | |
| Dos Reis et al. | Eddy-current evaluation of three-dimensional defects in a metal plate | |
| US9377554B2 (en) | Pore parameters and hydraulic parameters from electric impedance spectra | |
| Heidari et al. | A Biospectroscopic Assignment Technique for Gum Cancer Cell Membrane DNA/RNA Reconstituted in Magnetically Aligned Gum Cancer Cells for Solid-State NMR Analysis of Gum Cancer Cell Membrane DNA/RNA and Nucleic Acids Aggregates by Proton Detected Spectroscopy | |
| Watson et al. | Magnetic induction tomography |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| AD01 | Patent right deemed abandoned |
Effective date of abandoning: 20111130 |
|
| C20 | Patent right or utility model deemed to be abandoned or is abandoned |