CN108577838A - Multichannel electrical impedance tomography circuit and system - Google Patents
Multichannel electrical impedance tomography circuit and system Download PDFInfo
- Publication number
- CN108577838A CN108577838A CN201810476960.3A CN201810476960A CN108577838A CN 108577838 A CN108577838 A CN 108577838A CN 201810476960 A CN201810476960 A CN 201810476960A CN 108577838 A CN108577838 A CN 108577838A
- Authority
- CN
- China
- Prior art keywords
- signal
- module
- excitation
- processing unit
- central processing
- 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
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
- A61B5/053—Measuring electrical impedance or conductance of a portion of the body
- A61B5/0531—Measuring skin impedance
-
- 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
- A61B5/053—Measuring electrical impedance or conductance of a portion of the body
- A61B5/0536—Impedance imaging, e.g. by tomography
-
- 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
- A61B5/7225—Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation
Abstract
The present invention provides multichannel electrical impedance tomography circuit and systems, are related to the field of medical instrument technology, wherein the multichannel electrical impedance tomography circuit includes：Central processing unit, current excitation module, encourage assurance module, measurement module and back end processing module, in use, current excitation module is after receiving the detectable signal that central processing unit is sent out, any two test electrode into measurement module sends out current signal, excitation assurance module is used for current signal being adjusted to steady state value, exciting current signal is generated according to steady state value, in this way, remaining test electrode generates multichannel driving voltage signal under exciting current signal function, until all test electrodes all receive exciting current signal, the driving voltage signal that each back end processing module generates the test electrode being attached thereto generates conversion results signal after being amplified and converting, to send central processing unit imaging to, improve the efficiency and precision of imaging.
Description
Technical field
The present invention relates to the field of medical instrument technology more particularly to multichannel electrical impedance tomography circuit and systems.
Background technology
Bioelectrical impedance tomography technology is a kind of novel medicine functional imaging technology, its principle is in human body surface
Detection electrode is laid, and applies a faint electric current on the electrode and measures the voltage value on other electrodes later, according to
Relationship between voltage and electric current reconstructs inside of human body impedance value or the changing value of electrical impedance.Due in this method reality
Nucleic or ray are not used during applying, it is therefore, harmless, reuse can be repeatedly measured, its cost is relatively low in addition,
Special working environment is not required, and therefore, bioelectrical impedance tomography technology is that one kind is ideal, has broad prospect of application
Medical imaging technology.
But in traditional bioelectrical impedance tomography device, usually only four input/output switching compositions, i.e.,
There are two outputs to switch for emitting portion；There are two input switches for detection part.Due in bioelectrical impedance tomography device
Number of poles is more, the switch that the signal in above-mentioned multiple electrodes can not simultaneously Jing Guo emitting portion and detection part, therefore, on
The method of stating can only monitor slow change procedure in real time, although imaging still has functionality, limit its application
Range.By taking the bioelectrical impedance tomography device with 16 test electrodes as an example, when having 2 electrodes as pumping signal
When, adjacent voltage is required for obtaining two-by-two for other electrode (such as 14), then changes excitation electrode pair, all
After electrode is to (symmetrical or adjacent) cycle one time, hundreds of data are measured, according to this hundreds of data, are finally inversed by electrode institute really
The electrical impedance distribution of fixed plane.There is usually one amplifiers in existing device, therefore, it is difficult to meet high speed measure and
The requirement of measurement accuracy.
To sum up, problem relatively low about traditional slow precision of bioelectrical impedance tomography device to test at present, there is no
Effective solution method.
Invention content
In view of this, the embodiment of the present invention has been designed to provide multichannel electrical impedance tomography circuit and system,
By the way that central processing unit, current excitation module, excitation assurance module, measurement module and back end processing module is arranged, especially with
The back end processing module of each test electrode independent connection, improves the speed of signal transmission, and then ensured the efficiency of imaging
And precision.
In a first aspect, an embodiment of the present invention provides multichannel electrical impedance tomography circuits, including：Central processing unit,
Current excitation module, excitation assurance module, measurement module and back end processing module, wherein the number of the back end processing module
It is multiple；
The central processing unit, the excitation assurance module, the current excitation module, the measurement module and each institute
Back end processing module is stated to be sequentially connected, and, each back end processing module is connected with the central processing unit, wherein institute
It includes multiple test electrodes to state measurement module, and multiple test electrodes are evenly spaced in a plane, and, each survey
Examination electrode is connected with a back end processing module；
The current excitation module, for after receiving the detectable signal that the central processing unit is sent out, to the survey
Test electrode described in amount mould any two in the block sends out current signal, until all test electrodes all receive it is described
Until current signal；
The excitation assurance module generates according to the steady state value and swashs for the current signal to be adjusted to steady state value
Encourage current signal；
Remaining described test electrode, for generating multichannel driving voltage signal under the action of the exciting current signal；
Each back end processing module, the driving voltage for being generated to the test electrode being attached thereto are believed
Conversion results signal is generated after number being amplified and convert, and is imaged with sending the central processing unit to.
With reference to first aspect, an embodiment of the present invention provides the first possible embodiments of first aspect, wherein every
Include that detect and select switch, preamplifier, bandpass filter, the logarithm being sequentially connected are put in a back end processing module
Big device and A/D digital quantizers；
It is described to detect and select switch, for being connected to the preamplifier being connected with the test electrode；
The preamplifier obtains the first amplification voltage letter for carrying out Linear Amplifer to the driving voltage signal
Number；
The bandpass filter obtains band logical voltage signal for being filtered to the first amplification voltage signal；
The logafier obtains the second amplification voltage letter for carrying out logarithmic amplification to the band logical voltage signal
Number；
The A/D digital quantizers obtain digital voltage for carrying out analog-to-digital conversion to the second amplification voltage signal
Signal.
The possible embodiment of with reference to first aspect the first, an embodiment of the present invention provides second of first aspect
Possible embodiment, wherein multiple switches that detect and select are connected with the central processing unit；
Switch is detected and selected described in multiple, is used to be connected to remaining after the return path signal for receiving the central processing unit
Connection between the test electrode and the preamplifier.
The possible embodiment of with reference to first aspect the first, an embodiment of the present invention provides the third of first aspect
Possible embodiment, wherein further include the first calibrating resistance in each back end processing module；
One end of first calibrating resistance and the first calibrating resistance phase in the adjacent back end processing module
Even, it is circularized until first calibrating resistance in all back end processing modules is sequentially connected, the first calibration electricity
The other end of resistance is connected with the switch that detects and selects；
First calibrating resistance, for sending out the first calibration letter to the switch that detects and selects in the central processing unit
Number excitation under generate first voltage；
The central processing unit, for the difference between the first voltage measured and the first normal voltage to be denoted as
One measured error signal.
The third possible embodiment with reference to first aspect, an embodiment of the present invention provides the 4th kind of first aspect
Possible embodiment, wherein further include the second calibrating resistance in each back end processing module, wherein second school
Quasi- resistance is different from the resistance value of the first calibrating resistance；
One end of second calibrating resistance and the second calibrating resistance phase in the adjacent back end processing module
Even, it is circularized until second calibrating resistance in all back end processing modules is sequentially connected, the second calibration electricity
The other end of resistance is connected with the switch that detects and selects；
Second calibrating resistance, for sending out the second calibration letter to the switch that detects and selects in the central processing unit
Number excitation under generate second voltage；
The central processing unit, for the difference between the second voltage measured and the second normal voltage to be denoted as
Two measured error signals.
With reference to first aspect, an embodiment of the present invention provides the 5th kind of possible embodiments of first aspect, wherein institute
Current excitation module is stated to include the current source generator being sequentially connected, exciting amplifier and encourage selecting switch, and, the excitation
Selecting switch is connected with the central processing unit；
The current source generator, for generating excitation electricity after receiving the detectable signal that the central processing unit is sent out
Stream；
The exciting amplifier obtains the exciting current signal for being amplified to the exciting current；
The excitation selecting switch tests electrode for being connected under the control of the central processing unit described in any two
With the connection between the exciting amplifier.
The 5th kind of possible embodiment with reference to first aspect, an embodiment of the present invention provides the 6th kind of first aspect
Possible embodiment, wherein the number of the excitation selecting switch is two, and, two excitation selecting switch series connection,
One of them described excitation selecting switch ground connection；
The unearthed excitation selecting switch, for sending out exciting current signal to test electrode described in any two
During, level-one isolation is carried out to remaining described described test electrode；
The excitation selecting switch of ground connection, for sending out exciting current signal to test electrode described in any two
In the process, two level isolation is carried out to remaining described described test electrode.
With reference to first aspect, an embodiment of the present invention provides the 7th kind of possible embodiments of first aspect, wherein institute
It includes feedback detection resistance, feedback amplifier and feedback A/Ds to state excitation assurance module；
The exciting amplifier and the excitation selecting switch are connected with the input terminal of the feedback amplifier, described anti-
Feedback detection resistance is connected in parallel on the input terminal of the feedback amplifier, the feedback amplifier and the feedback A/Ds phase
Even, the feedback A/Ds are connected with the central processing unit；
The feedback detection resistance, for generating feedback pressure drop under the action of the exciting current signal；
The feedback amplifier, for being amplified to the feedback pressure drop；
The feedback A/Ds, for the amplified feedback pressure drop to be converted into digital pressure drop；
The central processing unit, for when judging that the digital pressure drop is less than preset steady state value, increasing the detection
Signal, to increase the size of the exciting current.
With reference to first aspect, an embodiment of the present invention provides the 8th kind of possible embodiments of first aspect, wherein institute
The number for stating test electrode is even number.
Second aspect, an embodiment of the present invention provides multichannel Electrical Impedance Tomography Systems, including：Host computer and above-mentioned
Any one of them multichannel electrical impedance tomography circuit；
The host computer is connected or is wirelessly connected by USB line with the multichannel electrical impedance tomography circuit；
The host computer is monitored in real time for the working condition to the multichannel electrical impedance tomography circuit.
Multichannel electrical impedance tomography circuit provided in an embodiment of the present invention and system, wherein the multichannel electrical impedance
Fault imaging circuit includes：Central processing unit, current excitation module, measurement module and back end processing module, in multichannel electricity
In impedance tomography circuit, the number of back end processing module is multiple, and above-mentioned central processing unit, measures current excitation module
Module and each back end processing module are sequentially connected, also, each back end processing module is connected with central processing unit, i.e., multiple
Back end processing module is all independent to be connected together to multiple signal returns to the channel of central processing unit, above-mentioned survey with central processing unit
It includes multiple test electrodes to measure module, also, multiple test electrodes are evenly spaced in a plane, each test electricity therein
Extremely it is connected with a back end processing module, in use, current excitation module is used to receive central processing unit hair
After the detectable signal gone out, any two test electrode into measurement module sends out exciting current signal, is tested to open
Journey, remaining test electrode are used to generate multichannel driving voltage signal under the action of exciting current signal, i.e., tested body is in quilt
The driving voltage signal generated after above-mentioned exciting current signal stimulus, later, each back end processing module are used for being attached thereto
The driving voltage signal that generates of test electrode be amplified after processing and analog-to-digital conversion and generate conversion results signal, to send to
Central processing unit carries out imaging, by above-mentioned processing procedure, realizes single test electrode and individual back-end processing mould
Block is connected, and the effect to work, in this way, multiple test electrodes in test process can be simultaneously by the excitation measured electricity
Stream signal return is handled to central processing unit, compared with existing processing mode, the multichannel electrical impedance tomography electricity
Road can realize high speed and high-precision signal processing, and then improve the efficiency of test.
Other features and advantages of the present invention will illustrate in the following description, also, partly become from specification
It obtains it is clear that understand through the implementation of the invention.The purpose of the present invention and other advantages are in specification, claims
And specifically noted structure is realized and is obtained in attached drawing.
To enable the above objects, features and advantages of the present invention to be clearer and more comprehensible, preferred embodiment cited below particularly, and coordinate
Appended attached drawing, is described in detail below.
Description of the drawings
It, below will be to specific in order to illustrate more clearly of the specific embodiment of the invention or technical solution in the prior art
Embodiment or attached drawing needed to be used in the description of the prior art are briefly described, it should be apparent that, in being described below
Attached drawing is some embodiments of the present invention, for those of ordinary skill in the art, before not making the creative labor
It puts, other drawings may also be obtained based on these drawings.
Fig. 1 shows the connection figure for the multichannel electrical impedance tomography circuit that the embodiment of the present invention is provided；
Fig. 2 shows the connection diagrams for the multichannel electrical impedance tomography circuit that the embodiment of the present invention is provided；
Fig. 3 shows the structure connection figure for the multichannel Electrical Impedance Tomography System that the embodiment of the present invention is provided.
Icon：1- central processing units；2- current excitation modules；3- encourages assurance module；4- measurement modules；5- back-end processings
Module.
Specific implementation mode
Below in conjunction with attached drawing in the embodiment of the present invention, technical solution in the embodiment of the present invention carries out clear, complete
Ground describes, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Usually exist
The component of the embodiment of the present invention described and illustrated in attached drawing can be arranged and be designed with a variety of different configurations herein.Cause
This, the detailed description of the embodiment of the present invention to providing in the accompanying drawings is not intended to limit claimed invention below
Range, but it is merely representative of the selected embodiment of the present invention.Based on the embodiment of the present invention, those skilled in the art are not doing
The every other embodiment obtained under the premise of going out creative work, shall fall within the protection scope of the present invention.
In existing bioelectrical impedance tomography device, in general, two output switches only are arranged in emitting portion, use
To send pumping signal to test electrode；Two input switches are arranged in detection part, and being used for will be aitiogenic to pumping signal
Return path signal (for example, driving voltage signal etc.) returns to processor one by one.Due in bioelectrical impedance tomography device
Number of poles is more, the switch that the signal in above-mentioned multiple electrodes can not simultaneously Jing Guo emitting portion and detection part, Zhi Nengyi
One transmission, in this way, causing the speed of detection slower, measuring accuracy can not also ensure, although imaging still has functionality, limit
Its application range is made.
Based on this, an embodiment of the present invention provides multichannel electrical impedance tomography circuit and systems, below by implementation
Example is described.
Embodiment 1
Referring to Fig. 1 and Fig. 2, the multichannel electrical impedance tomography circuit that the present embodiment proposes specifically includes：Central processing
Device 1, current excitation module 2, excitation assurance module 3, measurement module 4 and back end processing module 5 need to illustrate herein
It is that the number of back end processing module is multiple, by the way that multiple back end processing modules are arranged so that the passback being connected with test module
Par wise irrelevance between channel, each independent back end processing module are used for handling the return path signal in a test process, when having
When multiple test signals generate simultaneously, you can return to central processing unit simultaneously by above-mentioned each test module and further locate
Reason.
Connection relation under lower mask body is introduced between above-mentioned modules：Above-mentioned central processing unit, excitation assurance module,
Current excitation module, measurement module and each back end processing module are sequentially connected, also, each back end processing module is and central
Processor is connected, wherein and measurement module includes multiple test electrodes, and multiple test electrodes are evenly spaced in a plane, and
And each test electrode is connected with a back end processing module, needs to illustrate, above-mentioned measurement module includes more
A test electrode, in general, the number of test electrode is even number, to facilitate optional two of which as the electrode of input,
In the present embodiment, the number for testing electrode is 16.When in use, in order to ensure that test signal can be uniformly distributed, multiple surveys
Examination electrode is evenly spaced in a plane, and each electrode of testing is connected with a back end processing module, in this way, a test
Electrode and a back end processing module connect into independent return path.
After test is opened, current excitation module is used for after receiving the detectable signal that central processing unit is sent out, to survey
Amount mould any two test electrode in the block sends out current signal.Here, central processing unit sends out detectable signal to measurement module
It is the generation for promoting current signal in measurement module, i.e., test process is opened with this.Assurance module is encouraged to be used for current signal
It is adjusted to steady state value, exciting current signal is generated according to steady state value, i.e., exciting current signal is ensured by the setting of steady state value
Size.Due to, include multiple test electrodes in measurement module, also, the effect of each test electrode is identical, it is each to test
The location of electrode is also identical.In this way, during the test, optionally any two of which test electrode it can be used as reception and swash
The test electrode for encouraging current signal, signal is as uniform as possible in order to detect, and generally selects the test electrode of two opposite ends.In general,
Pumping signal is single sine wave, to obtain the high sensitivity measured；Or the overlaid waveforms of limited multiple sine waves, to measure mesh
Target frequency characteristic, compared with the current signals such as square wave, the variation of sine wave excitation currents signal is more steady, can improve measurement
Sensitivity.All any twos test electrode calculates a test until all receiving exciting current signal in above-mentioned test process
Process when usually used, can repeat above-mentioned test process (at least twice), then the result tested every time is done one linearly
Fitting.
In this way, remaining test electrode is used to generate multichannel driving voltage signal under the action of exciting current signal, surveying
After examination person receives above-mentioned exciting current signal, position that can be where testing electrode generates reaction, and is being placed on the position
Remaining test electrode on generate multichannel driving voltage signal, i.e., one test electrode on generate driving voltage signal all the way.
Later, after each back end processing module receives driving voltage signal, each back end processing module is to phase therewith
The driving voltage signal that test electrode even generates generates multiple conversion results signals accordingly after being carried out at the same time amplification and conversion,
And it sends central processing unit to and is imaged.Since the setting of multiple back end processing modules can be to multichannel driving voltage signal
Parallel processing is carried out, to improve the processing capacity that driving voltage signal is amplified and is converted.
Include the detection being sequentially connected in the multichannel electrical impedance tomography circuit, in each back end processing module
Selecting switch, preamplifier, bandpass filter, logafier and A/D digital quantizers detect and select switch connection and survey
The connected preamplifier of electrode is tried, i.e., before circuit is not used, is detected and selected between switch and preamplifier in disconnection shape
State, also, multiple switches that detect and select are connected with central processing unit, in the circuit in use, multiple detect and select switch
Connection for being connected to after the return path signal for receiving central processing unit between remaining test electrode and preamplifier, with shape
At the connection relation one by one between test electrode and preamplifier.In general, return path signal is to send out spy by central processing unit
It is generated after delay a period of time after survey signal, the length of specific a period of time can carry out flexibly according to the concrete condition of circuit
Setting.
Above-mentioned preamplifier is used for carrying out Linear Amplifer to driving voltage signal, obtains the first amplification voltage signal, with
Ensure the integrality of driving voltage signal fed back.Later, amplify voltage signal with bandpass filter pair first to filter
Wave obtains band logical voltage signal, by the use of bandpass filter, effectively reduces the relatively low frequency in driving voltage signal waveform
Part and higher-frequency part, the reason is that, it is relatively more compared with the interference that low frequency part and higher-frequency part are adulterated, pass through bandpass filtering
More live parts can be got.Later, logarithmic amplification is carried out to band logical voltage signal with logafier, obtains the second amplification
Voltage signal, traditional design are all the linear amplifiers of variable gain, due to the shape of a saddle logarithm point of electrical impedance imaging signal
Cloth, can be to the measurement of useful signal higher resolution using logafier.And a small amount of big signal still can ensure phase
To resolution ratio.Logafier can provide small signal bigger gain；And smaller gain is provided big signal.
In the present embodiment, since the test electrode close to excitation end may obtain the detection signal of the about half of driving voltage signal.
And the signal obtained apart from the test electrode of excitation end farther out is exponentially decayed.Logafier will be far from the excitation electricity at excitation end
Signal is pressed to carry out the amplification of more large gain, to substantially increase the resolution ratio of signal.Getting above-mentioned driving voltage signal
Afterwards, amplify voltage signal with A/D digital quantizers pair second and carry out analog-to-digital conversion, digital voltage signal is obtained, so as to center
Processor is further processed digital voltage signal.
Due to the parameter meeting and standard parameter that electronic component in circuit etc. is made under different manufacturing process
Difference, moreover, the connection relation between electronic component can also influence the accuracy of configured transmission.It is tested on electrode in view of being added in
Exciting current signal it is fainter, in order to reduce influence of the circuit to test process itself, reduce and use A/D digital quantizers
Carry out the error in transfer process.Further include the first calibrating resistance in above-mentioned each back end processing module, the first calibrating resistance
One end is connected with the first calibrating resistance in adjacent back end processing module, until the first calibration in all back end processing modules
Resistance, which is sequentially connected, to be circularized, and is continued for testing the number of electrode and be 16, and exactly the 1st detects and selects switch connection
First calibrating resistance is connect with the 2nd the first calibrating resistance for detecting and selecting switch closed on, and so on, the 16th detection choosing
The first calibrating resistance that the 1st the first calibrating resistance for detecting and selecting switch for selecting switch detects and selects switch with the 1st is connect, the
The other end of one calibrating resistance is connected with switch is detected and selected, and in use, the first calibrating resistance is used in central processing
Device generates first voltage to detecting and selecting switch and send out under the excitation of the first calibration signal, central processing unit be used to measure the
Difference between one voltage and the first normal voltage is denoted as the first measured error signal.
Since, circuit is to the generally linear variation of response of pumping signal, rather than fixed value.Therefore, each rear end
Further include the second calibrating resistance in processing module, needs to illustrate, the resistance of the second calibrating resistance and the first calibrating resistance
Value is different, i.e., weighs its error, one end of the second calibrating resistance and adjacent back-end processing by the resistance of different resistance values
Mould the second calibrating resistance in the block is connected, and is circularized until the second calibrating resistance in all back end processing modules is sequentially connected,
The other end of second calibrating resistance is connected with switch is detected and selected, and in use, the second calibrating resistance can be in centre
Reason device generates second voltage to detecting and selecting switch and send out under the excitation of the second calibration signal, central processing unit will measure second
Difference between voltage and the second normal voltage is denoted as the second measured error signal.
Also, central processing unit calculates above-mentioned modulus according to above-mentioned first measured error signal and the second measured error signal
Conversing circuits (the analog-to-digital conversion circuit be include A/D digital quantizers, the first calibrating resistance and the second calibrating resistance circuit)
Interference value, for example, sending out the excitation (for example, 1mA electric currents) of the first calibration signal to switch is detected and selected in central processing unit
Lower generation first voltage, it is assumed that 1mA is Vr1=1V under 1k Ohmic resistances, and actual measured value is Vad1=1.08V；Resistance
100 ohm of generation Vr2=0.1V, and actual measured value is Vad2=0.11V；Bring equation Vad=a*Vr+b into；Calculate a=
(Vad1-Vad2)/(Vr1-Vr2)=1.078；B=1.08-1.078*1=0.002；Vad=1.078*V+0.002, practical electricity
V=(Vad-0.002)/1.078 is pressed, is measured so just more accurate.In addition, it is necessary to illustrate, when actual implementation, is
It is measured twice, and the result by measuring twice does an once linear fitting to determine final measurement error.
In addition, in the present embodiment current excitation module include the current source generator being sequentially connected, exciting amplifier and
Selecting switch is encouraged, also, selecting switch is encouraged to be connected with central processing unit, in implementation process, current source generator is connecing
Exciting current is generated after receiving the detectable signal that central processing unit is sent out, uses current source generator to be sent out as detectable signal here
Raw device, can ensure the stability of electric current during the test, avoid remaining electronic component to the electric current in test
It influences.Later, exciting amplifier obtains exciting current signal, has with guarantee sufficiently large for being amplified to exciting current
Electric current reaches human body and is tested.Also, excitation selecting switch is connected to any two test electricity under the control of central processing unit
Connection between pole and exciting amplifier.By encouraging the setting of selecting switch that can effectively respond the control of central processing unit
System, and two are selected to be tested from above-mentioned 16 test electrodes.
In addition, being tested to further ensure that sufficiently large electric current reaches human body, excitation in the present embodiment is protected
Barrier module includes feedback detection resistance, feedback amplifier and feedback A/Ds, the connection between above-mentioned all parts
Relationship is：Exciting amplifier and excitation selecting switch are connected with the input terminal of feedback amplifier, and feedback detection resistance is connected in parallel on
On the input terminal of feedback amplifier, feedback amplifier is connected with feedback A/Ds, feedback A/Ds and central processing
Device is connected, in use, feedback detection resistance is used to generate feedback pressure drop under the action of exciting current signal, feedback amplifier is used
It is amplified in feedback pressure drop, feedback A/Ds are used to amplified feedback pressure drop being converted into digital pressure drop, center
Processor is used to, when the digital pressure drop of judgement is less than preset steady state value, increase detectable signal, to increase the size of exciting current,
The numerical value specifically adjusted can be adjusted according to the feedback pressure drop measured in real time, so as to further ensure exciting current signal
Numerical value it is sufficiently large, keep test process safe and effective.
Since meeting is by the exciting current signal in circuit during encouraging selecting switch to carry out open and close
It influences, for example, when excitation selecting switch be closed two-way therein come when gating the test electrode being attached thereto, other 14 tunnel
Encourage selecting switch can be during above-mentioned two-way is closed by rush of current.In the present embodiment, selecting switch is encouraged
Number is two, also, two excitation selecting switch series connection, i.e., only there are two could will be encouraged when excitation selecting switch is all connected
Current signal transfer gives test electrode.It needs to illustrate, one of excitation selecting switch ground connection, by exciting current
The influence access the earth generated when signal flows through.In specific implementation process, unearthed excitation selecting switch be used for appoint
During two test electrodes of meaning send out exciting current signal, level-one isolation, i.e. any two are carried out to remaining test electrode
When testing the excitation selecting switch conducting corresponding to electrode, there is exciting current signal warp in any two test electrode of conducting
It crosses, the excitation selecting switch corresponding to remaining test electrode does not turn on, although can be influenced by the exciting current signal passed through,
But level-one isolation is effectively carried out due to not turning on.On this basis, the excitation selecting switch of ground connection be used for appoint
During two test electrodes of meaning send out exciting current signal, two level isolation is carried out to remaining test electrode, i.e., it is above-mentioned not lead
Excitation selecting switch corresponding to remaining logical test electrode the excitation selecting switch of concatenated ground connection can be by the sharp of process
The influence for encouraging current signal further weakens, to ensure the measuring accuracy of test electrode.
In conclusion multichannel electrical impedance tomography circuit provided in this embodiment includes：Central processing unit, electric current swash
Encourage module, excitation assurance module, measurement module and back end processing module, wherein the number of back end processing module is multiple, center
Processor, excitation assurance module, current excitation module, measurement module and each back end processing module are sequentially connected, also, each
Back end processing module is connected with central processing unit, wherein measurement module includes multiple test electrodes, also, multiple tests are electric
Pole is evenly spaced in a plane, and each electrode of testing is connected with a back end processing module, in use, electric current
Encourage module after receiving the detectable signal that central processing unit is sent out, any two test electrode into measurement module is sent out
Current signal, excitation assurance module are used for current signal being adjusted to steady state value, and exciting current signal is generated according to steady state value, this
Sample, remaining test electrode generate multichannel driving voltage signal under the action of exciting current signal, subsequently carry out parallel processing, i.e.,
The driving voltage signal that each back end processing module generates the test electrode being attached thereto generates after being amplified and converting to be turned
Change consequential signal, be imaged with sending central processing unit to, by above-mentioned processing procedure, accelerate bio-electrical impedance tomography at
As the test speed of device, its measuring accuracy is improved.
Embodiment 2
Referring to Fig. 3, present embodiments providing multichannel Electrical Impedance Tomography System includes：Host computer and any of the above-described
Multichannel electrical impedance tomography circuit, need exist for illustrating, host computer and multichannel electrical impedance tomography
Circuit is connected or is wirelessly connected by USB line, specifically, between host computer and multichannel electrical impedance tomography circuit
When distance is closer, connected by USB line, it is convenient and efficient；When between host computer and multichannel electrical impedance tomography circuit away from
From farther out either line inconvenience when, by being wirelessly connected, in this way, host computer can be to multichannel electrical impedance tomography electricity
The working condition on road is monitored in real time, in order to which manager can observe multichannel electrical impedance tomography circuit in real time
Working condition.
In conclusion multichannel Electrical Impedance Tomography System provided in this embodiment includes：Host computer and any of the above-described
Multichannel electrical impedance tomography circuit, host computer connected by USB line with multichannel electrical impedance tomography circuit or
Person is wirelessly connected, and in use, host computer is used to carry out the working condition of multichannel electrical impedance tomography circuit real
When monitor, consequently facilitating supervision and oversight.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description
Specific work process, can refer to previous embodiment in corresponding process, details are not described herein.
In addition, in the description of the embodiment of the present invention unless specifically defined or limited otherwise, term " installation ", " phase
Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected；It can
Can also be electrical connection to be mechanical connection；It can be directly connected, can also indirectly connected through an intermediary, Ke Yishi
Connection inside two elements.To those skilled in the art, it can understand above-mentioned term in the present invention with concrete condition
Concrete meaning.
In the description of the present invention, it should be noted that term "center", "upper", "lower", "left", "right", "vertical",
The orientation or positional relationship of the instructions such as "horizontal", "inner", "outside" be based on the orientation or positional relationship shown in the drawings, merely to
Convenient for the description present invention and simplify description, do not indicate or imply the indicated device or element must have a particular orientation,
With specific azimuth configuration and operation, therefore it is not considered as limiting the invention.
Finally it should be noted that：Embodiment described above, only specific implementation mode of the invention, to illustrate the present invention
Technical solution, rather than its limitations, scope of protection of the present invention is not limited thereto, although with reference to the foregoing embodiments to this hair
It is bright to be described in detail, it will be understood by those of ordinary skill in the art that：Any one skilled in the art
In the technical scope disclosed by the present invention, it can still modify to the technical solution recorded in previous embodiment or can be light
It is readily conceivable that variation or equivalent replacement of some of the technical features；And these modifications, variation or replacement, do not make
The essence of corresponding technical solution is detached from the spirit and scope of technical solution of the embodiment of the present invention, should all cover the protection in the present invention
Within the scope of.Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. a kind of multichannel electrical impedance tomography circuit, which is characterized in that including：Central processing unit, swashs at current excitation module
Encourage assurance module, measurement module and back end processing module, wherein the number of the back end processing module is multiple；
The central processing unit, the excitation assurance module, the current excitation module, the measurement module and it is each it is described after
End processing module is sequentially connected, and, each back end processing module is connected with the central processing unit, wherein the survey
It includes multiple test electrodes to measure module, and multiple test electrodes are evenly spaced in a plane, and, each test electricity
Extremely it is connected with a back end processing module；
The current excitation module, for after receiving the detectable signal that the central processing unit is sent out, to the measurement mould
Electrode is tested described in any two in the block and sends out current signal, until all test electrodes all receive the electric current
Until signal；
The excitation assurance module generates excitation electricity for the current signal to be adjusted to steady state value according to the steady state value
Flow signal；
Remaining described test electrode, for generating multichannel driving voltage signal under the action of the exciting current signal；
Each back end processing module, the driving voltage signal for being generated to the test electrode being attached thereto into
Conversion results signal is generated after row amplification and conversion, is imaged with sending the central processing unit to.
2. multichannel electrical impedance tomography circuit according to claim 1, which is characterized in that each back-end processing
In module switch, preamplifier, bandpass filter, logafier and A/D numbers are detected and selected including what is be sequentially connected
Converter；
It is described to detect and select switch, for being connected to the preamplifier being connected with the test electrode；
The preamplifier obtains the first amplification voltage signal for carrying out Linear Amplifer to the driving voltage signal；
The bandpass filter obtains band logical voltage signal for being filtered to the first amplification voltage signal；
The logafier obtains the second amplification voltage signal for carrying out logarithmic amplification to the band logical voltage signal；
The A/D digital quantizers obtain digital voltage letter for carrying out analog-to-digital conversion to the second amplification voltage signal
Number.
3. multichannel electrical impedance tomography circuit according to claim 2, which is characterized in that detected and selected described in multiple
Switch is connected with the central processing unit；
Switch is detected and selected described in multiple, is used to be connected to described in remaining after the return path signal for receiving the central processing unit
Test the connection between electrode and the preamplifier.
4. multichannel electrical impedance tomography circuit according to claim 2, which is characterized in that each back-end processing
It further include the first calibrating resistance in module；
One end of first calibrating resistance is connected with first calibrating resistance in the adjacent back end processing module, directly
Be sequentially connected and circularize to first calibrating resistance in all back end processing modules, first calibrating resistance it is another
One end is connected with the switch that detects and selects；
First calibrating resistance, for sending out the first calibration signal to the switch that detects and selects in the central processing unit
Excitation is lower to generate first voltage；
The central processing unit, for the difference between the first voltage measured and the first normal voltage to be denoted as the first survey
Measure error signal.
5. multichannel electrical impedance tomography circuit according to claim 4, which is characterized in that each back-end processing
Further include the second calibrating resistance in module, wherein second calibrating resistance is different from the resistance value of the first calibrating resistance；
One end of second calibrating resistance is connected with second calibrating resistance in the adjacent back end processing module, directly
Be sequentially connected and circularize to second calibrating resistance in all back end processing modules, second calibrating resistance it is another
One end is connected with the switch that detects and selects；
Second calibrating resistance, for sending out the second calibration signal to the switch that detects and selects in the central processing unit
Excitation is lower to generate second voltage；
The central processing unit, for the difference between the second voltage measured and the second normal voltage to be denoted as the second survey
Measure error signal.
6. multichannel electrical impedance tomography circuit according to claim 1, which is characterized in that the current excitation module
Including be sequentially connected current source generator, exciting amplifier and excitation selecting switch, and, the excitation selecting switch with it is described
Central processing unit is connected；
The current source generator, for generating exciting current after receiving the detectable signal that the central processing unit is sent out；
The exciting amplifier obtains the exciting current signal for being amplified to the exciting current；
The excitation selecting switch, for being connected to test electrode and institute described in any two under the control of the central processing unit
State the connection between exciting amplifier.
7. multichannel electrical impedance tomography circuit according to claim 6, which is characterized in that the excitation selecting switch
Number be two, and, two excitation selecting switch series connection, one of them described excitation selecting switch is grounded；
The unearthed excitation selecting switch, in the mistake for sending out exciting current signal to test electrode described in any two
Cheng Zhong carries out level-one isolation to remaining described described test electrode；
The excitation selecting switch of ground connection, in the process for sending out exciting current signal to test electrode described in any two
In, two level isolation is carried out to remaining described described test electrode.
8. multichannel electrical impedance tomography circuit according to claim 6, which is characterized in that the excitation assurance module
Including feedback detection resistance, feedback amplifier and feedback A/Ds；
The exciting amplifier and the excitation selecting switch are connected with the input terminal of the feedback amplifier, the feedback inspection
Measuring resistance is connected in parallel on the input terminal of the feedback amplifier, and the feedback amplifier is connected with the feedback A/Ds,
The feedback A/Ds are connected with the central processing unit；
The feedback detection resistance, for generating feedback pressure drop under the action of the exciting current signal；
The feedback amplifier, for being amplified to the feedback pressure drop；
The feedback A/Ds, for the amplified feedback pressure drop to be converted into digital pressure drop；
The central processing unit, for when judging that the digital pressure drop is less than preset steady state value, increasing the detectable signal,
To increase the size of the exciting current.
9. multichannel electrical impedance tomography circuit according to claim 1, which is characterized in that of the test electrode
Number is even number.
10. a kind of multichannel Electrical Impedance Tomography System, which is characterized in that including：Host computer and such as claim 1-9 are any
Multichannel electrical impedance tomography circuit described in；
The host computer is connected or is wirelessly connected by USB line with the multichannel electrical impedance tomography circuit；
The host computer is monitored in real time for the working condition to the multichannel electrical impedance tomography circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810476960.3A CN108577838A (en) | 2018-05-17 | 2018-05-17 | Multichannel electrical impedance tomography circuit and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810476960.3A CN108577838A (en) | 2018-05-17 | 2018-05-17 | Multichannel electrical impedance tomography circuit and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108577838A true CN108577838A (en) | 2018-09-28 |
Family
ID=63631825
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810476960.3A Pending CN108577838A (en) | 2018-05-17 | 2018-05-17 | Multichannel electrical impedance tomography circuit and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108577838A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114366068A (en) * | 2021-12-29 | 2022-04-19 | 杭州永川科技有限公司 | Modularized high-speed electrical impedance imaging device and using method |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101199418A (en) * | 2006-12-12 | 2008-06-18 | 深圳迈瑞生物医疗电子股份有限公司 | Brain impedance detection circuitry and EEG checking device |
| CN104007322A (en) * | 2014-06-12 | 2014-08-27 | 中国人民解放军第四军医大学 | High-precision data acquisition system for electrical impedance imaging |
| CN204188204U (en) * | 2014-11-14 | 2015-03-04 | 成都汉康信息产业有限公司 | Based on the Urban Data harvester of double copies |
| CN104605851A (en) * | 2015-02-16 | 2015-05-13 | 天津大学 | Electrical impedance tomography (EIT) system data acquisition method |
| CN104983422A (en) * | 2015-07-17 | 2015-10-21 | 南京邮电大学 | Electrical impedance tomography device of electrodes 32 |
| CN105652756A (en) * | 2016-03-21 | 2016-06-08 | 成都爆米花信息技术有限公司 | Safe multichannel data collection system |
| CN105652755A (en) * | 2016-03-21 | 2016-06-08 | 成都爆米花信息技术有限公司 | Safe and improved multichannel data collection system |
| CN105943045A (en) * | 2016-05-18 | 2016-09-21 | 上海交通大学 | High-precision bio-electrical impedance measuring system and method for body composition analysis |
| CN105976411A (en) * | 2016-05-18 | 2016-09-28 | 中国人民解放军第四军医大学 | Prepositioned measuring module for electrical impedance tomography imaging data acquisition system and alignment and calibration method |
| CN106526499A (en) * | 2016-11-04 | 2017-03-22 | 北京无线电计量测试研究所 | Highly-stable current source examination method and system |
| CN107320101A (en) * | 2017-06-20 | 2017-11-07 | 南京邮电大学 | A kind of multifrequency electric impedance imaging system |
-
2018
- 2018-05-17 CN CN201810476960.3A patent/CN108577838A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101199418A (en) * | 2006-12-12 | 2008-06-18 | 深圳迈瑞生物医疗电子股份有限公司 | Brain impedance detection circuitry and EEG checking device |
| CN104007322A (en) * | 2014-06-12 | 2014-08-27 | 中国人民解放军第四军医大学 | High-precision data acquisition system for electrical impedance imaging |
| CN204188204U (en) * | 2014-11-14 | 2015-03-04 | 成都汉康信息产业有限公司 | Based on the Urban Data harvester of double copies |
| CN104605851A (en) * | 2015-02-16 | 2015-05-13 | 天津大学 | Electrical impedance tomography (EIT) system data acquisition method |
| CN104983422A (en) * | 2015-07-17 | 2015-10-21 | 南京邮电大学 | Electrical impedance tomography device of electrodes 32 |
| CN105652756A (en) * | 2016-03-21 | 2016-06-08 | 成都爆米花信息技术有限公司 | Safe multichannel data collection system |
| CN105652755A (en) * | 2016-03-21 | 2016-06-08 | 成都爆米花信息技术有限公司 | Safe and improved multichannel data collection system |
| CN105943045A (en) * | 2016-05-18 | 2016-09-21 | 上海交通大学 | High-precision bio-electrical impedance measuring system and method for body composition analysis |
| CN105976411A (en) * | 2016-05-18 | 2016-09-28 | 中国人民解放军第四军医大学 | Prepositioned measuring module for electrical impedance tomography imaging data acquisition system and alignment and calibration method |
| CN106526499A (en) * | 2016-11-04 | 2017-03-22 | 北京无线电计量测试研究所 | Highly-stable current source examination method and system |
| CN107320101A (en) * | 2017-06-20 | 2017-11-07 | 南京邮电大学 | A kind of multifrequency electric impedance imaging system |
Non-Patent Citations (2)
| Title |
|---|
| 尤富生: "电阻抗断层成像硬件系统", 《国外医学生物医学工程分册》 * |
| 徐佳芝, 李颖: "《生物医学电阻抗成像技术》", 30 June 2010, 机械工业出版社 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114366068A (en) * | 2021-12-29 | 2022-04-19 | 杭州永川科技有限公司 | Modularized high-speed electrical impedance imaging device and using method |
| CN114366068B (en) * | 2021-12-29 | 2022-08-09 | 杭州永川科技有限公司 | Modularized high-speed electrical impedance imaging device and using method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7940038B2 (en) | Grid sensor for the two-dimensional measurement of different components in the cross section of a multiphase flow | |
| JP6714317B2 (en) | Probe and its usage | |
| CN111722044B (en) | Direct current charging pile testing method, device and equipment based on frequency sweep calibration shunt | |
| WO2006074092A1 (en) | High precision voltage source for electrical impedance tomography | |
| CN105484740B (en) | A kind of multifrequency detection device for being used to detect stratum complex resistivity | |
| CN105606905B (en) | Electromagnetic radiation monitoring instrument with weighted function | |
| CN106443196A (en) | Electrode grounding resistance measuring system and electrode grounding resistance measuring method | |
| CN108577838A (en) | Multichannel electrical impedance tomography circuit and system | |
| US7417424B2 (en) | Magnetic-field-measuring device | |
| CN108685572A (en) | Multichannel electrical impedance tomography circuit and system | |
| CN206863126U (en) | Resistance measurement system and resistance measuring equipment | |
| CN208969228U (en) | A kind of Magnetic Sensor static and dynamic performance caliberating device charging straight wire surrounding magnetic field | |
| CN105806390A (en) | Magnetoelastic sensor detection system | |
| CN109781798A (en) | A kind of electric pole tower ground net corrosion detection method and system | |
| CN213398688U (en) | Multifunctional tester and testing system | |
| CN204694667U (en) | Based on the two-dimentional concrete parameters tester of reinforcing bar electrode | |
| Mikulka et al. | A Fast and Low-cost Measuring System for Electrical Impedance Tomography | |
| Dušek et al. | Designing a cost-effective multiplexer for electrical impedance tomography | |
| CN106053944B (en) | A kind of rock resistivity measurement instrument and measurement method | |
| CN105866714A (en) | Magnetic field intensity detecting suite | |
| Ranade et al. | Design and development of instrumentation for acquiring electrical impedance tomography data | |
| CN218767101U (en) | Magnetizing current measuring device of magnetic particle flaw detector | |
| CN212433331U (en) | Circuit assembly electrical parameter detection device for suspension wire pendulum type accelerometer | |
| CN212410881U (en) | Magnetotelluric far reference point and observation point power frequency interference investigation device thereof | |
| CN211826221U (en) | Input front end of single-phase power quality analyzer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20180928 |