The organism surface electric signal detection method of temperature error can be reducedTechnical field
The present invention relates to a kind of application method of the detection electrode array suitable for organism surface ultra-weak electronic signal, especiallyIt is related to a kind of organism surface electric signal detection method for reducing temperature error.
Background technology
The electric signal detection of organism surface is always one of problem of biomedical sector.The electric signal of organism surface is visitedSurvey has problems with：
1st, signal amplitude is very faint, such as neuropotential, electromyography signal, can not be straight with conventional detection method and equipmentIt obtains and takes, if introducing amplifier, very big interference can be brought and so that original signal feature is flooded by noise signal.
2nd, the acquisition of existing bioelectrical signals largely uses microelectrode, and tactile in order to obtain electroneurographic signal, biologyThe small-signals such as signalling, in order to avoid noise, using intrusive detection method (such as needle electrode), not only to tested biologyBody brings additional injury, and can introduce new noise.
3rd, bio signal is non-stationary signal, and randomness is strong, according to different test condition and demand, the state of electrode andDetection method needs to change in time.
4th, because of the characteristic of organism and bio signal in itself, existing detection electrode can not ensure the consistent of test conditionProperty.
In view of the above-mentioned problems, the present invention proposes a kind of electrod-array detection system for the detection of organism surface ultra-weak electronic signalSystem.
Invention content
The technical problems to be solved by the invention are to provide a kind of efficient, reliable electricity for organism body surface ultra-weak electronic signalPole detection system, to realize the stabilization of electric signal, efficiently detection.
In order to solve the above technical problems, the present invention uses following technical scheme：
A kind of organism surface ultra-weak electronic signal detection electrode system, the electrode holder including using flexible printed circuit board,The electrode holder is connected up using circuitron, and the electrode points of array-like arrangement, the electrode are equipped on electrode holderElectrode lattice array of carrier or so is averagely divided into 2 regions, and be respectively adopted the printed circuit board wiring of 2-3mm as ground wire intoThe totally-enclosed encirclement of row, and pad is set in the electrode points, and realizes scolding tin and weldering in a manner that scolding tin fills padThe electrical connection of disk, scolding tin electroplate or silver chlorate print electricity in the wherein one side of the electrode holder using double-sided circuit wiringEach electrode points pad is electrically connected to common interface end by road by printed wiring, and common interface end is connected to by shielded cableDriving source and signal picker, common interface end can as needed to detect point electrode detection/excitation and level state intoRow controls, and is additionally provided with miniature adding thermal resistance in the electrode points, miniature adding thermal resistance passes through the PCB cloth with pad opposite sideLine, is connected to common interface end, and the miniature adding thermal resistance connects, and miniature adding thermal resistance ontology is embedded in weldering with pad in insulationAmong tin.The organism surface ultra-weak electronic signal detection electrode system, it is characterised in that：Scolding tin filling in the electrode pointsHigh unity is controlled in 5mm, and shape is hemispherical.
The matching used detection system of the detection electrode, designing points are as follows：It is made and connected of low frequency shielded cableLine component, avoid ultra-weak electronic signal interferes with each other and introduces noise.Its wiring includes the data connecting line of each electrode points, connectsEarth signal transmits special circuit.Data connecting line and ground signal line are staggered to reduce to greatest extent between signal wireCrosstalk.Output port is connect with control circuit board, and the circuit of control circuit board with electrode detector be connected, ensure ground connection electricityThe unification of position.
Control system include signal front end input photoelectric coupling amplification module, low-pass filtering module, single chip control module,Export amplification module, memory module, input keyboard.Photoelectric coupling amplification module is amplified using the integration of OPA series photoelectric couplingsChip；Low-pass filtering module irrigates husband's wave filter using second order Bart, and cutoff frequency is designed as 15kHz.Microcontroller controls mouldBlock carries out input, output signal coordination control, and connects E2ROM chips or USB chips by serial port, realizes acquisition numberAccording on piece storage or USB external memories storage.
The PCB design of the control system uses the design method of multigroup shielding, and ground wire is connected up using the ultra-wide of 2-3mm,And walks wire shaped surrounds form for closed loop, so that the electrode in the range of ground wire encirclement realizes higher isolation effect.
Microcontroller control flow is as follows：
Array-type electrode point on electrode holder is divided into 4 regions, and the printed circuit board wiring that 2-3mm is respectively adopted is madeTotally-enclosed encirclement is carried out for ground wire, is often arranged in parallel with electric heating wire between row electrode in four regions, the electric heating wire has 2A electrical connection pins are connected to common interface end by the printed circuit board wiring on printed circuit board carrier, and electrode base board entersAfter state to be measured, microcontroller detects, and result of detection is interim to being scanned formula on substrate per first electrode signal of a lineIt is stored in E2ROM or external memory, realizes and the resting potential (DC level) of all electrode points is measured, all sweepVm is maximized after the completion of retouching, and electrode points scanning is calibrated one by one again, the calibrating mode is：To removing Vm placesAll rows except row carry out scanning probe, while each electric heating wire is heated, heating later stage probe value Vi (i=1,2,3 ...) it will increase, when Vi is increased within 5% limits of error of Vm values, then microcontroller control gates rows of electrodes two where ViThe heating wire of side stops heating, until all first electrode points probe value Vi and Vm value differences of rows of electrodes away from being within 5%Only, you can proceed by actual detection.
The organism body surface electric signals detection electrode of the present invention is arranged using flexible, insulation material as electrod-arrayCarrier, electrode base present hemispherical surface contacted with body surface, all electrodes can according to bio signal detect need realize volumeJourney can also connect oscillograph or signal pickup assembly as detection electrode using connection signal generator as excitation electrode,It can also be grounded as bucking electrode.If necessary to detect the transmission characteristic of constant level in vivo, can also will detectOr excitation electrode is directly set as high/low level position, it can be achieved that the measurement of the high speed, flexibility of organism surface signal.
The control terminal of the detection system is formed including following sections：Circuit board, singlechip chip and its peripheral circuit,Switch arrays and its address wire and data line, signal acquisition circuit module, memory module, signal excitation module, host computer communicationModule, input Keysheet module and display module.
The system controls switch arrays using microcontroller as core, and on off state is conducting, then corresponding port isTo be measured or excitation state, it is ground state that on off state, which disconnects then corresponding port, and low level is presented.Switch arrays pass through addressLine and data line and single chip communication, and receive microcontroller control.
Signal acquisition circuit includes pre-amplifier, photoelectric coupling circuit, power isolation module and low-pass filter.It is describedPre-amplifier selects three groups of common amplifier devices to form differential amplifier with suppression common mode noise；In photoelectric coupling circuit selectionPortion carries the integral type instrumentation amplifier of Phototube Coupling, power isolation module selection DC/DC isolating chips.Low-pass filter usesButterworth second order filter, cutoff frequency 8kHz-15kHz.
Above-mentioned module is grounded using one point grounding mode, and control module surface uses metallic shield to prevent electromagnetismInterference.
Compared with existing electro physiology Detection Techniques, the present invention has following technique effect：
1) it can detect or encourage simultaneously, and realize test and storage at a high speed, high-throughput with on-plane surface multiple spot.
2) in actual detection in application, the detection electrode system need to only fix once, subsequent each electrode condition can basisMcu programming is realized, with the consistency of guarantee test condition to greatest extent.
3) electrod-array can be bonded, while in electrode using flexible PCB as substrate according to organism surface shapeSilver chlorate is plated as unpolarized electrode in surface, maximally reduces the introducing of contact link noise.
4) by setting the ground connection of several, a row or multi-row electrode on electrod-array, excitation letter can be effectively realizedNumber, detectable signal in isolation electrically, to prevent the appearance of artefact.
5) Intelligent Single-Chip Based control, a variety of connection modes, low noise are employed for the detection system of the electrode array designsSound design etc., realizes the efficient detection for body surface electricity physiological signal.
Description of the drawings
Fig. 1 is organism surface electric signal detection electrode array schematic top plan view.
Fig. 2 is the schematic side view of electrode unit in organism surface electric signal detection electrode array.
Specific embodiment
Below in conjunction with the accompanying drawings, it elaborates, as shown in Figure 1 and Figure 2, using the electrode holder 3 of flexible printed circuit board,The electrode points 2 of array-like arrangement are equipped on electrode holder 3, the electrode holder 3 is divided into 4 regions, and 2- is respectively adoptedThe printed circuit board wiring of 3mm carries out totally-enclosed encirclement as ground wire 1, is often arranged in parallel between row or each column electrode in four regionsThere is electric heating wire 6, the electric heating wire 6 there are 2 electrical connection pins, passes through the printed circuit board wiring on printed circuit board carrier 3Common interface end 5 is connected to, gating is carried out as needed by microcontroller and part heater strip therein is controlled to be in working condition.InstitutePad 6 in the electrode points 2 stated is set, and being electrically connected for scolding tin 7 and pad 6, scolding tin are realized in a manner that scolding tin 7 fills padThe pad 6 of each electrode points 2 is electrically connected to common interface end by electroplate or silver chlorate 8 by printing creel 4 on circuit boards5, common interface end 5 is connected to driving source and signal picker by shielded cable, and common interface end 5 can be as needed to detectionThe detection/excitation and level state of point electrode are controlled, and electrode base is presented hemispherical surface and is contacted with body surface.
Using low frequency shielded cable, preferably coaxial cable makes connecting line component, avoids interfering with each other for ultra-weak electronic signalWith introducing noise.Its wiring includes the data connecting line of each electrode points, ground signalling transmission special circuit.Data connecting line withGround signal line is staggered to reduce the crosstalk between signal wire to greatest extent.Output port 5 is connect with control circuit board,And the circuit of control circuit board with electrode detector be connected, ensure the unification of earthing potential.
Signal control terminal includes：Signal front end input photoelectric coupling amplification module, low-pass filtering module, microcontroller control mouldBlock, output amplification module, external memory module, input keyboard, the single chip control module pass through serial port and memory moduleConnection, the external memory module use E2ROM chips or FLASH flash chips.It is selected by mcu programming control channelThe state of device, realizes the electrode selection of electrod-array, and determines that operating mode is input or output, if input pattern, thenSignal inputs microcontroller, and then by monolithic after photoelectric coupling, amplifying circuit, low-pass filter circuit, microcontroller input interfaceMachine system is stored in external memory module, realizes the acquisition of electrode signal；If output mode, then produced according to SCM programRaw signal realizes the excitation of electrode signal by being added to after amplification module, channel to channel adapter on specified electrode, particularly, hereinThe signal exported under pattern is 0, then electrode potential is 0, and working condition is ground connection (shielding)；By microcontroller to channel to channel adapterThe cycle selection of each channel, realizes the control of all electrode conditions on electrod-array.Using SCM system by address wire,The working condition of each electrode is set separately in data line, is one in grounding electrode (bucking electrode), detection electrode, excitation electrodeKind.Meanwhile the heating wire specified can be gated into row energization by microcontroller, it is made to generate heat.
The photoelectric coupling amplification module uses OPA series photoelectric coupling integration amplification chips, the low-pass filtering mouldBlock irrigates husband's wave filter using second order Bart, and cutoff frequency is designed as 11kHz-15kHz, and 1-3 can be used in the channel to channel adapterPiece CD4067 chips.
Array-type electrode point on electrode holder is divided into 4 regions, and the printed circuit board wiring that 2-3mm is respectively adopted is madeTotally-enclosed encirclement is carried out for ground wire, is often arranged in parallel with electric heating wire between row electrode in four regions, the electric heating wire has 2A electrical connection pins are connected to common interface end by the printed circuit board wiring on printed circuit board carrier.According to experimental program,The working condition of each electrode is set separately by address wire, data line using SCM system, be grounding electrode, detection electrode,Encourage one kind in electrode.Excitation, detectable signal are realized in isolation electrically, a signal transmission is formed on the electrode and leads toRoad.
After electrode base board enters state to be measured, microcontroller is visited to being scanned formula on substrate per first electrode signal of a lineIt surveys, and result of detection is temporarily stored in E2ROM or external memory, realize the resting potential (direct current to all electrode pointsLevel) it is measured, Vm is all maximized after the completion of scanning, and electrode points scanning is calibrated one by one again, the schoolQuasi- mode is：Scanning probe is carried out, while each electric heating wire is heated to removing all rows except Vm is expert at, addedHot later stage probe value Vi (i=1,2,3 ...) will increase, when Vi is increased within 5% limits of error of Vm values, then microcontroller controlThe heating wire of rows of electrodes both sides stops heating where system gating Vi, until all rows of electrodes first electrode points probe value Vi and VmValue difference is away from until within 5%, you can proceeds by actual detection.The value of the DC level of electrode is using flat in 1msMean value.
Preset input signal is selected.Typical input signal may be selected：Square wave, triangular wave, sine wave, high electricityFlat, low level.The collection period of the peak-to-peak value (mV) of output drive signal, period (ms) and detection electrode is concurrently set, it is excellentIt is selected as 0.05ms.Electrode is driven according to setting, while by the data of concurrently or sequentially mode scanning probe electrode points,It is stored in a memory cell in the form of discrete data point.