CN207081682U - A kind of saliva impedance detection device and equipment - Google Patents

Abstract

The utility model discloses a kind of saliva impedance detection device and equipment.The device includes：Analog signal interface circuit (8), for obtaining the analog voltage signal at the saliva impedance both ends collected, and send to analog signal processing module (9)；Analog signal processing module (9), it is connected with analog signal interface circuit (8), for being pre-processed to analog voltage signal, obtains the voltage signal of pretreated analog quantity；A/D modular converters (10), for carrying out analog-to-digital conversion to the voltage signal of pretreated analog quantity, obtain the voltage signal of digital quantity and send to processor (11)；Processor (11), it is connected with A/D modular converters (10), the voltage signal of digital quantity is calculated for receiving the voltage signal of digital quantity, and based on Ohm's law, obtains saliva impedance.The utility model can accurately measure to obtain saliva impedance, and then allow to carry out onset of ovulation prediction using saliva impedance.

Description

A kind of saliva impedance detection device and equipment

Technical field

Health care equipment technical field is the utility model is related to, more particularly to a kind of saliva impedance detection device and is set It is standby.

Background technology

The prediction female ovulation date is reproductive medicine research such as artificial insemination, inseminatio externalis and instructs Sterility patient to grasp The key link that the opportunity of becoming pregnant is treated, it is significant to the clinic and research work of gynemetrics, it is also beneficial to simultaneously Implement timed-pregnant to realize prenatal and postnatal care and promote natural contraception.The Accurate Prediction female ovulation date not only contributes to defeat infertile Infertility, and be advantageous to prenatal and postnatal care, have very important significance.

The electrical characteristics of biological tissue refer to the faint alternating current less than excited value by when the conductive spy that is shown Property and dielectric property, it be living organism and tissue important electrical properties.The research of biological properties is in terms of medical science New householder method is brought using with characteristic, diagnosis and treatment to disease such as easy not damaged, rapid and continuous measurements And means.The electrical characteristics of biological fluid (such as saliva, blood, urine, cervical mucus) are measured, also just from an integral level Reflect the change of composition and concentration and the change of hormone in vivo in body fluid and dependency relation, particularly women be present, due to Hormone in vivo periodically changes, and causes the ion concentration in body fluid that the fluctuation increasedd or decreased is presented.Therefore, body fluid is measured Electrical characteristics reflect the change of hormone in vivo to a certain extent, and some features also just reflected in determining female physiological periodicity become Change.Found by medical research, internal estrogen changes in menstrual cycle of female has very strong correlation with ovulation rule.It is female Hormone change causes the change in concentration of electrolyte ion in saliva of buccal cavity again, and the change of electrolyte ion concentration shows in saliva Change for its equiva lent impedance, it is foreseen that the impedance operator of electrolyte concentration has with ovulation rule in saliva of buccal cavity Certain correlation.Therefore, female ovulation day can be predicted by measuring the impedance operator of electrolyte concentration in saliva of buccal cavity Phase.

For the problem of the impedance operator of electrolyte concentration, not yet proposing effective solution at present in above-mentioned measurement saliva of buccal cavity Certainly scheme.

Utility model content

The purpose of this utility model is to provide a kind of saliva resistance for measuring the impedance operator of electrolyte concentration in saliva of buccal cavity Anti-detection devices and equipment.

According to the one side of the utility model embodiment, a kind of saliva impedance detection device, including analog signal interface Circuit, analog signal processing module, A/D modular converters and processor：Analog signal interface circuit, for obtaining the saliva collected The voltage signal of the analog quantity at liquid impedance both ends, and send to analog signal processing module；Analog signal processing module, with simulation Signal interface circuit connects, and for being pre-processed to the voltage signal of analog quantity, obtains the voltage of pretreated analog quantity Signal；A/D modular converters, for carrying out analog-to-digital conversion to the voltage signal of pretreated analog quantity, obtain the electricity of digital quantity Press signal and send to processor；Processor, it is connected with A/D modular converters, for receiving the voltage signal of digital quantity, and is based on Ohm's law is calculated the voltage signal of digital quantity, obtains saliva impedance.

According to the other side of the utility model embodiment, a kind of saliva impedance detection equipment, including a kind of resistance of saliva Anti-detection devices, in addition to：Saliva impedance detection is popped one's head in and exciting signal source, exciting signal source pass through a resistance and saliva impedance Detection probe is connected, and pumping signal is provided for saliva impedance detection probe；Saliva impedance detection is popped one's head in, for gathering saliva impedance The voltage signal of the analog quantity at both ends.

The saliva impedance detection device and equipment that the utility model embodiment provides, by saliva impedance detection device to saliva The analog voltage signal that liquid impedance detection probe measures carries out a series of processing, saliva impedance is finally calculated, so as to realize The effect of saliva of buccal cavity impedance operator is more accurately detected, and then calculated saliva impedance can assist prediction to arrange The ovum phase.

Brief description of the drawings

Fig. 1 is the overall structure diagram of saliva detection probe provided by the utility model；

Fig. 2 (a) is the schematic diagram of the point electrode shape of generally use in electrode impedance measurement in the prior art；

Fig. 2 (b) is the schematic diagram of the rectangular electrode shape of generally use in electrode impedance measurement in the prior art；

Fig. 2 (c) is the schematic diagram of the combination electrode shape of generally use in electrode impedance measurement in the prior art；

Fig. 3 (a) is electric current distribution schematic diagram in point electrode electric field domain in the prior art；

Fig. 3 (b) is electric current distribution schematic diagram in rectangular electrode electric field domain；

Fig. 4 is the arrangement schematic diagram of induced electricity pole piece in another embodiment of the utility model；

Fig. 5 is the overall structure diagram for the saliva detection probe that another embodiment of the utility model provides；

The typical equivalent model circuit structure diagram of Fig. 6 electrolyte solutions；

Fig. 7 is the electrolyte solution equivalent circuit structure figure after Fig. 6 simplification；

Fig. 8 is saliva parallel equivalent circuit structure diagram；

Fig. 9 is the impedance measurement equivalent circuit structure figure of saliva electrolyte solution；

Figure 10 is the structural representation of saliva impedance detection device；

Figure 11 is the circuit structure diagram of memory module in the utility model embodiment；

Figure 12 is the circuit structure diagram of communication module in the utility model embodiment；

Figure 13 (a) is the circuit structure diagram of processor control circuit in the utility model embodiment；

Figure 13 (b) is the circuit structure diagram of the test device of processor control circuit in the utility model embodiment；

Figure 14 is the circuit structure diagram of analog signal processing module in the utility model embodiment；

Figure 15 is the module connection diagram of amplifying circuit in the utility model embodiment；

Figure 16 is the circuit structure diagram of preamplifying circuit in the utility model embodiment；

Figure 17 is the circuit structure diagram of rear class amplifying circuit in the utility model embodiment；

Figure 18 is the schematic diagram of the impedance measurement of saliva electrolyte solution in the utility model embodiment；

Figure 19 is the pin distribution map of analog switch LVC4066D in the utility model embodiment；

Figure 20 is phase-sensitive detection circuit structure chart in the utility model embodiment；

Figure 21 is the circuit structure diagram of phase-sensitive detection circuit in the utility model embodiment；

Figure 22 is the circuit structure diagram of voltage follower circuit in the utility model embodiment；

Figure 23 is the circuit structure diagram of VCC/2 voltage follower circuits in the utility model embodiment；

Figure 24 is the circuit structure diagram of phase-sensitive detection circuit in the utility model embodiment；

Figure 25 is the power supply the principle figure of power supply circuit provided by the utility model；

Figure 26 is the circuit structure diagram of the first embodiment of power supply circuit provided by the utility model；

Figure 27 is the circuit structure diagram of the second embodiment of power supply circuit provided by the utility model；

Figure 28 is the circuit structure diagram of the 3rd embodiment of power supply circuit provided by the utility model；

Figure 29 is the circuit structure diagram of the 4th embodiment of power supply circuit provided by the utility model；

Figure 30 is the circuit structure diagram of exciting signal source in the utility model embodiment.

Reference：

1- carrying base portions, 2- induced electricity pole pieces, 3- communication lines, 4- interfaces, 5- grounding electrode pieces, 6- grip parts, 7- are solid Determine face, 8- analog signal interface circuits, 9- analog signal processing modules, 91- amplifying circuits, 910- preamplifying circuits, 911- Rear class amplifying circuit, 92- phase-sensitive detection circuits, 920- analog switches, 921- phase-shift circuits, 922- negative circuits, 93- voltages with With circuit, 94-VCC/2 voltage follower circuits, 95- phase sensitive detection signal processing circuits, 950- filter circuits, 10-A/D conversions Module, 11- processors, 12- display modules, 13- memory modules, 14- clock modules, 15- communication modules, 151- Bluetooth chips, 16- power modules, 17- exciting signal sources.

Embodiment

To make the purpose of this utility model, technical scheme and advantage of greater clarity, with reference to embodiment And referring to the drawings, the utility model is further described.It should be understood that these descriptions are merely illustrative, and do not really want Limit the scope of the utility model.In addition, in the following description, the description to known features and technology is eliminated, to avoid not Necessarily obscure concept of the present utility model.

The technical term that the utility model embodiment uses includes：

Impedance, it is the obstruction that is risen to alternating current in the circuit with resistance, inductance and electric capacity.

Faradaic impedance refers to that electric current passes through the activation polarization and concentration polarization that occur when electrolyte and electronic conductor interface Change caused additional impedance.

Capacitive reactance, it is used in obstruction that electric capacity rises to alternating current in circuit.

Referring to Fig. 1, the overall structure signal for the saliva impedance detection probe that Fig. 1, which is the utility model embodiment, to be provided Figure.

As shown in figure 1, in the present embodiment, saliva impedance detection probe includes：Carry base portion 1, induced electricity pole piece 2, lead to Believe circuit 3 and interface 4.

Wherein, carrying base portion 1 is sticked on saliva of buccal cavity surface.The volume of carrying base portion 1 is suitable can be put into human oral cavity Preferably.The position that is sticked for carrying base portion 1 can be to be sticked on tongue surface, can also be sticked on the cheek inwall of oral cavity, can be with It is sticked and is not limited in the oral cavity position that other have saliva, the scope of protection of the utility model by the set location for carrying base portion 1 System.

Induced electricity pole piece 2 be embedded carrying base portion 1 surface, i.e., one part be exposed to carrying base portion 1 surface, one Set up separately in the inside of carrying base portion 1.Induced electricity pole piece 2, which is used to contact with saliva of buccal cavity, forms physics electric loop so that oral cavity Saliva is equivalent to a blocked impedance in electric loop.One end of communication line 3 electrically connects with induced electricity pole piece 2, the other end with Interface 4 electrically connects, and communication line 3 is used to use to the input signal source of induced electricity pole piece 2, exciting signal source by interface 4 Ac square wave signal.

In the utility model, using AC signal as driving source, without using DC signal source, allowing for direct current letter Number source causes the displacement of free ion in biological tissue, produces polarity effect, causes the potential difference at electrode both ends and fold It is added in measurement voltage, has a strong impact on the accuracy of measurement；And alternating message source can efficiently reduce interelectrode polarity effect, Ensure measurement accuracy.

Operation principle of the present utility model is：Induced electricity pole piece 2 is placed in the oral cavity and contacts saliva of buccal cavity so that sense Electrode slice 2 is answered to form physics electric loop with saliva of buccal cavity, now, saliva of buccal cavity is equivalent to fixation resistance in electric loop It is anti-.By interface 4 and communication line 3 to the input stimulus alternating message source of induced electricity pole piece 2, in the driving of excitation alternating message source Under, the electric loop has electric current to flow through, now the magnitude of voltage at measurable saliva of buccal cavity equiva lent impedance both ends, obtains the equivalent resistance of saliva The analog voltage signal at anti-both ends.

In measurement process, there are the induced electricity pole piece 2 that electric current flows through and the electrolyte ion generation electrochemistry in saliva anti- Should, the polarization potential of a fluctuation change is produced, large effect can be produced to measurement result with voltage superposition to be measured.Cause This, to reduce the measurement error that electrode material electrochemical reaction is brought, the design of the shape and size of induced electricity pole piece 2 is very It is important.

The electrode of generally use has point electrode, rectangular electrode, combination electrode etc. several in electrode impedance measurement in the prior art Kind, electrode shape is as shown in Fig. 2 electric current distribution is as shown in Figure 3 in electric field domain.Fig. 2 (a) is that the shape of point electrode is illustrated Figure, Fig. 2 (b) are the schematic shapes of rectangular electrode, and Fig. 2 (c) is the schematic shapes of combination electrode；Fig. 3 (a) is point electrode electricity Electric current distribution schematic diagram in field domain, Fig. 3 (b) are electric current distribution schematic diagram in rectangular electrode electric field domain.

Point electrode is typically the circular electrode of diameter very little.Because contact area is very small, thus it can more measure " point " Potential information.The distribution of current density is similar to the electric force lines distribution between two spaces point electric charge in point electrode sensitivity field domain, As shown in Fig. 3 (a).The advantages of this shape electrode is that change in resistance is quick on the draw, and shortcoming is the geometry to electrode position Error is also sensitive, thus the alignment error of electrode has large effect to conductance measurement result.Line electrode is made up of filament, Available for the detection of liquid level or boundary, unsuitable usage scenario of the present utility model, excessive introduction wouldn't be done.

Rectangular electrode is obviously improved the uniformity of electric current distribution in electric field domain than point electrode, is measured in distribution of conductivity Middle application is more, as shown in Fig. 3 (a).In the case where medium is uniformly distributed, electric current distribution is similar to parallel in electric field domain Electric force lines distribution in plates capacitance, outside the edge effect in addition to pole plate fringe region, current density can be approximately considered in electricity It is uniformly distributed in field domain, its Electric Field Distribution is evenly distributed than point electrode, thus the sensitivity profile in its electric field domain is also just than point Electrode Field domain is uniform.Therefore, electric field caused by rectangular electrode or sensitive field, two dimensional electric field model is more met than point electrode.

Combination electrode is typically the combination of rectangular electrode and point electrode, and shown in Common Shape such as Fig. 3 (a), its principle is： Apply exciting current on rectangular electrode, to establish the preferable sensitivity field of uniformity, potential information is measured on point electrode, with more preferable Ground is measured the potential information of " point ".Combination electrode is a kind of electrode structure that medical domain proposes, the purpose is to comprehensive square The advantages of shape electrode and point electrode, i.e., produced than more uniform sensitivity field with rectangular electrode, believed with the potential of point electrode measurement point Breath.But processing, installation, the difficulty and complexity of process circuit are added during the application of electrode of this structure, generally very It is used less.

To sum up, point electrode is to measure the impedance between 2 points, it is impossible to reflects the overall impedance value of saliva, Er Qiedian completely Electrode pair change in resistance is quick on the draw, and the data deviation that measurement is repeated several times may be very big.Rectangular electrode is two electrodes of measurement Between equivalent entity impedance value, its electric current distribution is evenly distributed than point electrode, and caused electric field and sensitive field are all than point Electrode is uniform, can reflect the impedance operator of saliva entirety between electrode, more meets the impedance measurement model of two dimensional surface, however, Using rectangular electrode as during induced electricity pole piece 2, it is machined and the complexity of installation is larger, add cost of manufacture and when Between.

In another embodiment of the present utility model, the measurement brought to reduce electrode material electrochemical reaction misses Difference, accurately reflect the impedance operator that saliva is overall between electrode, and easily facilitate machining and installation, by considering and Repetition test, every induced electricity pole piece 2 of setting are shaped as circle.It should be noted that machining is in the prior art, by It is difficult to control in rectangle or other precision for having side and having the figure of rib, therefore its difficulty of processing and the difficulty of installation will be significantly larger than It is circular.The utility model embodiment can easily facilitate processing and installation using circle.

Electrode constant is used for the parameter for characterizing arrangement, shape and size between a pair of electrodes, reflect two electrodes it Between physical geometry property, directly affect the sensitivity and the degree of accuracy of measurement.Electrode constant is a constant, in induced electricity pole piece After relative position and size between 2 are fixed, the electrode constant of saliva impedance detection probe just determines therewith.Therefore, In the test process of reality, the parameters of induced electricity pole piece 2 are determined according to specific electrode constant.By each side Consider and repeatedly test, a diameter of 6mm-10mm of every induced electricity pole piece 2 of the present utility model, it is preferred that every induced electricity A diameter of 7mm-9mm of pole piece 2；Preferably, a diameter of 8mm of every induced electricity pole piece 2.It is of the present utility model to pass through standard Solution measures its electrode constant as 12 or so.

Referring to Fig. 4, Fig. 4 is the arrangement schematic diagram of induced electricity pole piece 2 in another embodiment of the utility model.In this implementation In example, in order to increase the equivalent cross-sectional area of induced electricity pole piece 2, and then the impedance for reducing electrode slice is realized, improve saliva impedance Measurement accuracy, the sensitivity of measurement is improved, the input for encouraging alternating message source is used for there is provided two circular induced electricity pole pieces 2. Preferably, in order to further improve the accuracy of measurement of saliva impedance, two induced electricity pole pieces 2 be arranged in parallel, and positioned at same Plane, to form same contact plane.Oral cavity tongue surface needs to be in close contact to form with induced electricity pole piece 2 electrically to detect back Road, saliva electrolyte is set to be equivalent to a resistance.Therefore induced electricity pole piece 2 is placed in parallel into composition contact plane to be advantageous to improve The accuracy of measurement of saliva impedance.

It is damaged in order to prevent from occurring in the cored wire of communication line 3 in another embodiment of the present utility model, leak Electric current threaten safeguard protection, be also provided with 1 grounding electrode piece 5, the grounding electrode piece 5 be used for connect ground wire.Preferably, originally In embodiment, two induced electricity pole pieces 2 and 5 arrangement triangular in shape of grounding electrode piece, and it is embedded the arc in carrying base portion 1 The center on surface.

In another embodiment of the present utility model, induced electricity pole piece 2 uses stainless steel, preferably using medical 316 stainless steels.

As a rule, it must is fulfilled for for doing the material of electrode：1. electrode has good electric conductivity, it is desirable to electrode material The conductance of material must be significantly higher than measured medium, and to ensure electrode surface as equipotential surface, current density is perpendicular to electrode surface It is uniformly distributed；2. electrode has stable electrochemical properties, due to chemistry or electrochemistry occurring between electrode and measured medium Reaction meeting corroding electrode surface, and measurement error is brought, therefore it is required that electrode has stable chemical characteristic.Following table is several electricity Electrochemical properties at 20 DEG C of pole material normal temperature.

Electrochemical properties at 20 DEG C of the Different electrodes material normal temperature of table 1

It was found from from upper table 1, electrode material has copper, stainless steel, silver, gold, nickel and carbon etc., may serve to do electrode. The material for meeting the utility model induction electrode requirement should have good machining property, and easily fixed and welding, heat should Power is small etc..

Because induction electrode needs to be positioned in oral cavity, it is desirable to which electrode material should be harmless, therefore carbon electrode is uncomfortable Cooperate as the electrode material of saliva impedance detection probe.From the perspective of batch production use, it is desirable to which electrode material is more normal With and be readily available, thus nickel be also not suitable for as saliva impedance detection probe electrode material.Come in terms of instrument cost Consider, it is desirable to electrode material it is cheap, although and the chemical property such as common electrode material gold, silver and platinum is stable, Price is high, greatly improves instrument hardware cost, therefore also unsuitable is used as electrode material.For synthesis, copper and not The relative electrode material for being suitable as saliva impedance detection probe of rust steel.

The chemical formula of medical 316 stainless steel is 0Cr18Ni12Mo2, due to the Ni nickel containing 18% Cr (chromium) and 10%, So abbreviation 18-10 again.Contain Mo elements in material, make its corrosion resistance, atmospheric corrosion resistance and having excellent high-temperature strength, resistance to height Temperature can reach 1200~1300 degree, can it is severe it is cruel under conditions of use.It is strain hardening functional, gone sightseeing outside cold-rolled products Damp degree is good.Medical 316 stainless steel is nontoxic to human body, and electrochemical properties are highly stable, does not have metal under "on" position completely Elemental release.During the utility model is realized, inventor combines the application scenarios of the utility model saliva detection probe, Pay performing creative labour and test of many times and comparison are carried out to various materials in the prior art, find medical 316 stainless steel tool There is excellent AC impedance performance, the needs of bio-electrical impedance measuring can be met as the electrode special in ac-excited source, because This thinks that medical 316 stainless steel abbreviation 18-10 is the most suitable as the material of induced electricity pole piece 2.

Referring to Fig. 5, the overall structure for the saliva impedance detection probe that Fig. 5, which is another embodiment of the utility model, to be provided is shown It is intended to.In view of the inconvenience of other position saliva measurements and complexity in oral cavity, the saliva impedance on tongue surface in oral cavity is measured For preferred scheme.

As shown in figure 5, in the present embodiment, the end surface shape for carrying one end that induced electricity pole piece 2 is provided with base portion 1 is circle Shape or ellipse, are provided with stationary plane 7 in circular or ellipse lower section, and stationary plane 7 is along circular or ellipse lower edge Curve extends.

Saliva impedance measurement is the process of a dynamic continuance collection in oral cavity, and the stationary plane that the present embodiment provides is easy to saliva Liquid impedance detection probe is more stable to be sticked on tongue surface, and tongue surface can be made to be connect with saliva impedance detection detecting head surface Good and fixed relative position is touched to ensure to measure stability, so as to be advantageous to the accuracy of signal acquisition, and then is advantageous to carry High measurement accuracy.

In another embodiment of the utility model, carrying base portion 1 is also associated with the grip part 6 in strip, setting in grip part 6 It is equipped with the receiving channel for accommodating communication line 3.The setting of grip part 6, was both easy to user to grip, and was advantageous to keep visiting again The health of head base portion.

Excitation alternating message source can produce magnetic field when passing through wire, it is not only possible to the normal work of peripheral devices is influenceed, and And easily disturbed by surrounding environment magnetic field, so as to influence the signal quality of exciting signal source.In another reality of the utility model Apply in example, communication line 3 uses shielded cable, ensures the quality of excitation alternating message source.Specifically, shielded cable includes：Absolutely Edge layer, screen layer, excitation AC signal wire and shielding layer grounding wire；Two-way excitation AC signal wire connects two respectively Induced electricity pole piece 2；Shielding layer grounding wire electrical connection grounding electrode piece 5.

Insulating barrier is the requirement by its withstanding voltage degree by insulating materials, be wrapped in different thickness outside conductor and Into for excitation AC signal wire and the screen layer of insulating；Polymeric barrier layer materials generally weave copper mesh or copper pool aluminium, for swashing Encourage AC signal wire to be protected, while also prevent from disturbing external devices in cable electromagnetic-field-shielded；Excitation exchange letter Number wire is the conductor for conducting electric current, is generally made with material with good conductivity；Shielding layer grounding wire can play Certain ground protection effect, if breakage occurs in cable core, the electric current leaked can be flowed into along screen layer and is grounded Net, play a part of safeguard protection.Shielded cable of the present utility model effectively shields interference signal, reduces driving source letter Number transmission loss, realize the protective effect to signal.

In another embodiment of the present utility model, carrying base portion 1 uses medical POM materials.Interface 4 using USB or Person 3.5mm COBBAIFs 4.Interface 4 mainly realizes the electrical connection with signal transacting mainboard, and the utility model preferably uses 3.5mm COBBAIFs 4, to realize that the contact performance of interface 4 is good, it is easy to plug to consolidate, fatigue performance is good and service life It is long.

When using the analog voltage signal at above-mentioned saliva impedance detection probe collection saliva impedance both ends, its measuring principle It is specific as follows：

Because the Main Ingredients and Appearance in saliva is water, electrolyte ion and protein, thus saliva may be considered containing one Determine the solution of concentration electrolyte.During the utility model is realized, inventor has found special by the electrochemistry of electrolyte solution Property analysis it is known that saliva and induction electrode can form a complicated electro-chemical systems after powered up.By by the electrification System progressively simplifies and modeled, and can calculate the impedance of saliva electrolyte solution, i.e. saliva impedance.According to test condition with And simplify the difference of object, can be equivalent by saliva electrolyte solution when progressively simplifying the electro-chemical systems and modeling For a variety of different circuits, can preferably matching test effect, find out the electrical conductive behavior rule of saliva electrolyte solution.

When progressively simplifying to electro-chemical systems and modeling, the typical equivalent of saliva electrolyte solution is introduced first Model, refer to Fig. 6, and Fig. 6 is the typical equivalent model circuit of electrolyte solution.

The implication of each symbol is as follows in Fig. 6：RL1, RL2 represent the lead resistance of induction electrode, and Cd1, Cd2 represent double electricity Layer capacitance, Z1, Z2 represent Faradaic impedance, Rs be electrolyte solution impedance, lead capacitances of the Cp between induction electrode. During impedance measurement, if directly using equivalent model in Fig. 6 to be handled, its calculation process and its complexity, in addition, in reality During existing the utility model, in face of above-mentioned technical problem, inventor has found：In the electrolytic process of solution, induction electrode Both ends can produce serious polarity effect when applying continuous current excitation signal includes chemical polarization and concentration polarization, makes the equivalent of solution Resistance has increase tendency, causes measurement error.If pumping signal uses ac-excited source, such as ambipolar sinusoidal or side Ripple, it can effectively reduce the influence that polarity effect is measured solution resistance.Compared to continuous current excitation signal, ac-excited signal energy The accuracy of measurement of solution resistance is farthest improved, but ac-excited signal can also bring the shadow of capacitive reactance in measuring loop into Ring, therefore to select the influence of suitable ac-excited signal frequency reduction capacitive reactance.Based on considerations above, the utility model uses Bipolarity ac square wave signal can reduce the measurement error that polarity effect is brought well as exciting signal source.

The electrolyte solution equivalent circuit in Fig. 6 is simplified according to the AC characteristic of exciting signal source, after it simplifies Electrolyte solution equivalent circuit it is as shown in Figure 7.Cd represents electric double layer capacitance in figure, and usual unit is the uF orders of magnitude；Cp is electricity Pole pin distribution capacity, usual unit are the pF orders of magnitude.

Because the solution resistance Rs high conductances of human saliva to be measured are relatively low, Cd capacitor values are smaller in Fig. 7, thus hold It is anti-to can be ignored.It is hereby achieved that saliva parallel equivalent circuit, as shown in Figure 8.

In figure, the electrical model of saliva electrolyte solution can be equivalent to resistance Rs and electric capacity Cp parallel circuit, and originally Purpose of utility model is resistance Rs to be obtained precise measurements, and reduces electric capacity Cp as far as possible to resistance Rs accuracies of measurement Influence.According to the electrochemistry equivalent circuit of saliva electrolyte solution, the method that the utility model devises impedance partial pressure realizes saliva The impedance measurement of liquid electrolyte solution, its circuit structure are as shown in Figure 9.R is high-precision divider resistance in Fig. 9, if dotted line frame The equiva lent impedance of interior saliva is Rt, and excitation alternating message source is Vin, and the magnitude of voltage at saliva equiva lent impedance both ends is Vout, the electricity The specific measuring principle on road is as follows：Encourage alternating message source to produce the bipolarity ac square wave signal Vin of amplitude stability, and pass through Divider resistance R is connected to induction electrode, and measuring loop is formed with saliva equiva lent impedance.From electric circuit knowledge, voltage measurement point Magnitude of voltage Vout calculation formula be：

In above formula, Vin is known input resistance R magnitude of voltage, thus only needs to measure the magnitude of voltage of voltage measurement point Vout, then it can calculate the equivalent resistance Rt of saliva, then the electrode parameter can of the induction electrode by having demarcated in advance Calculate the resistivity of saliva electrolyte solution.

The saliva equiva lent impedance both ends in saliva electrolyte solution equivalent circuit is obtained according to above-mentioned measuring principle measurement After voltage signal, send and carry out subsequent treatment into saliva impedance detection device, to obtain saliva impedance data.Specifically, please Refering to Figure 10, Figure 10 is the structural representation of the saliva impedance detection device of the utility model embodiment.

As shown in Figure 10, the saliva impedance detection device includes：

Analog signal interface circuit 8, analog signal processing module 9, A/D modular converters 10 and processor 11：

Analog signal interface circuit 8, the voltage signal of the analog quantity for obtaining the saliva impedance both ends collected, concurrently Deliver to analog signal processing module 9；The voltage signal of analog quantity is specially the ac square-wave voltage signal of analog quantity, is saliva resistance The voltage signal of the saliva of buccal cavity of anti-detection probe detection.

Analog signal interface circuit 8 is to obtain the saliva that the saliva impedance detection probe that above-described embodiment makes referrals to collects The ac square-wave voltage signal of the analog quantity at impedance both ends；

Analog signal processing module 9, it is connected with analog signal interface circuit 8, for the voltage signal progress to analog quantity Pretreatment, obtains the voltage signal of pretreated analog quantity；

A/D modular converters 10, for carrying out analog-to-digital conversion to the voltage signal of pretreated analog quantity, obtain digital quantity Voltage signal and send to processor 11；

Processor 11, it is connected with A/D modular converters 10, for receiving the voltage signal of digital quantity, and is based on Ohm's law The voltage signal of digital quantity is calculated, obtains saliva impedance.

Alternatively, processor 11 is microprocessor, and its function is to obtain the voltage signal of the quantity after A/D is changed, that is, is counted The saliva impedance voltage signal of word amount, and the saliva impedance voltage signal of digital quantity is stored and/or calculation process.

In a preferred embodiment, saliva impedance detection device also includes：Display module 12, connect with processor 11 Connect, for being shown to the saliva impedance being calculated.Display module 12 is preferably LCD MODULE.

The effect of display module 12 is to realize the real-time display for the saliva impedance data that processor 11 is calculated.This practicality Display device of the new selection LCD1602 Liquid Crystal Modules as saliva impedance detection device, it is a kind of dedicated for display word The lattice type LCD of mother, numeral, symbol etc., it is often capable at most to show 16 characters, 2 rows can be shown.LCD1602 liquid crystal moulds The capacity of display of block is 16 × 2 characters, and chip operating voltage is 2.7~5.5V, and operating current is 2.0mA (voltage 3.3V). LCD1602 selects 16 pin Liquid Crystal Modules, root using 14 pin of standard without backlight or 16 tape backlight interfaces, the utility model The display output of i.e. controllable Liquid Crystal Module is operated to its each pin according to the operation principle of Liquid Crystal Module.LCD1602 liquid crystal The pin interface explanation of module is as shown in table 2.

The LCD1602 Liquid Crystal Module pin interface explanations of table 2

In upper table, the 3rd pin VL is liquid crystal display setting contrast end, and contrast is most weak when connecing positive supply, during ground connection Contrast highest, it can be produced when contrast is too high " ghost ", the potentiometer that can pass through a 10K during use adjusts contrast. 4th pin RS is that register selects end, selection instruction register when selecting data register, low level during high level.5th draws Pin R/W is reading writing signal line, carries out read operation during high level, carries out write operation during low level.When RS and R/W are low electricity jointly Usually can be with write instruction or display address, when RS is that low level R/W can read busy signal when being high level, when RS is high electricity Flat R/W can write data when being low level.6th pin E ends are Enable Pin, when E ends by high level saltus step into low level when, Liquid Crystal Module performs order.7th~14 pin D0~D7 is 8 bidirectional data lines, and the 15th pin is backlight positive pole, and the 16th draws Pin is LED-OV.

In a preferred embodiment, saliva impedance detection device also includes：Memory module 13, calculated for storing The saliva impedance arrived and/or the voltage signal of digital quantity.Memory module is used to store measurement result data, in the control of processor 11 It is operated under system, the utility model selection IC chip 24LCS52 design memory modules.24LCS52 chips are one Capacity is 2Kbit Electrically Erasable Read Only Memory EEPROM, not only with small volume, low-power consumption and operating voltage The features such as allowed band is wide, also with capacity it is big, follow I2C bus protocols, take pin is few, capacity extension configuration flexibly and The features such as read-write operation is relatively easy.24LCS52 chips have the function of carrying out write-protect to internal data by software design patterns. Chip is sent special instruction can turn-on data writing protection function, and data writing protection function cannot be removed once opening Pin.Except software writing protection function, chip also has a WP pin to realize the write-protect of data, and without considering that software writes guarantor Whether shield register is set.These functions allow system designer to choose whether to need logarithm according to different application scenarios According to progress write-protect.The memory capacity of 24LCS52 chips is monolithic 256*8bit, enters line number by two-wire system I2C serial line interfaces According to communication；The low voltage designs of chip allow to use as little as 2.5v, and holding state electric current is 5uA, and working condition electric current is 1mA； There is chip data page to write function, and most multipotency continuously writes 16 byte datas.

It is as shown in figure 11 according to the memory module circuit that storage chip 24LCS52 is designed.Figure chips pin A1, A2, A3 Pin is selected for address of devices, can at most use 8 devices simultaneously；VCC, VSS be device power supply, pin, for chip supply Electricity, VCC pin connect+3.3V digital powers.SCL is serial shift clock input pin, when writing data, rising edge effect；Read When going out data, trailing edge effect.SDA is serial date transfer-output pin, realizes the transmitted in both directions of data.A0, A1 and A2 Pin connects+3.3V digital powers, and WP pins do not connect.

In a preferred embodiment, saliva impedance detection device also includes：Clock module 14, connect with processor 11 Connect, for timing wake-up processor 11.

In a preferred embodiment, saliva impedance detection device also includes：Communication module 15, connect with processor 11 Connect, communicated to connect for being established with external equipment, and the saliva impedance that processor 11 is calculated is sent to external equipment.Outside Portion's equipment can be intelligent terminal, can be APP specifically.

Preferably, communication module 15 is wireless communication module.It is further preferable that communication module 15 is bluetooth module；

Saliva impedance detection device in the utility model embodiment can be set by communication module 15 and the intelligence such as mobile phone It is standby to be communicated, the saliva impedance data being calculated is transferred in smart machine, so as to the APP application energy on smart machine The physiological health of women is preferably managed with reference to women other physical traits.

Because the saliva impedance detection device in the utility model embodiment is powered using battery, it is contemplated that bluetooth mould The cost performance and low power capabilities of block, the utility model realize that data communicate using low-power consumption bluetooth chip NRF51822. NRF51822 Bluetooth chips are high performance-cost ratio, high flexibility, powerful multi-protocols single-chip, are applied toLow-power consumption and 2.4GHz ultra-low power consumption wireless applications.And NRF51822 has abundant analog- and digital- periphery Product, PPI systems can be interconnected by programmable peripheral product in the case where being participated in without microprocessor and carry out interaction.Flexibly 31 pin GPIO mapping schemes can make I/O such as serial line interface, PWM and sinusoidal demodulation device according to PCB demands indicate map To any equipment pin.This can realize complete design flexibility and Pin locations and function.

NRF51822 supports S110 Bluetooth Low Energies protocol stack and 2.4GHz protocol stacks, both protocol stacks to exist Provided free in NRF518 software development kits.NRF51822 need individually power supply, if supply district 1.8-3.6V it Between, user may be selected using the linear rectifier on chip, if supply district between 2.1-3.6V, can select direct current DC-DC transformers in 1.8V patterns and chip.The particular technique parameter of NRF51822 Bluetooth chips refers to its specification, root The bluetooth 4.0BLE communication module circuitries designed according to the chip are as shown in figure 12.

Bluetooth module includes：Bluetooth chip 151, a crystal in parallel between the XC1 pins and XC2 pins of Bluetooth chip 151 It is connected respectively with electric capacity C15, C14 after oscillator Y1, electric capacity C14 and electric capacity C15 capacitance are 12pF；DEC1 pin serial connections One electric capacity C11, electric capacity C11 capacitance are 100nF, and the ANT2 pins of Bluetooth chip are connected with tie point and the second branch road, Tie point include series connection electric capacity C10 and inductance L4, inductance L4 both ends difference shunt capacitance C11 and electric capacity C12, electric capacity C10, Electric capacity C11 and electric capacity C12 capacitance are respectively 2.2nF, 1.0pF and 1.5pF；Second branch road includes the inductance L2 of series connection, electricity Feel L3 and electric capacity C9, inductance L2, inductance L3 inductance value are respectively 4.7nH and 10nH, and electric capacity C9 capacitance is 2.2nF；Pin meets electric capacity C8, and electric capacity C8 capacitance is 47nF；SWCLK pin connecting resistance R23, resistance R23 resistance value are 12K；The ANT1 pins of Bluetooth chip are connected between inductance L2 and inductance L3, and the VDD_PA pins of Bluetooth chip are connected to inductance Between L3 and electric capacity C9.Pin P0.00, pin P0.01 connect clock signal, and analog power pin VSS includes pin 13,33 and 34 ground connection；Two digital power pins VDD are also connected with electric capacity C6, C7 respectively when connecing digital power, and its capacitance is When 0.1uF, AVDD pin connect power supply, also it is connected with electric capacity C13, its capacitance is 1.0nF.

Data after the processing of processor 11, which can be sent to display module 12, to be shown, alternatively, display module 12 is LCD MODULE, the equipment such as mobile phone can also be transferred to as desired by communication module 15, alternatively, communication module 15 is Bluetooth 4.0BLE communication modes.Processor 11 provides includes foregoing display module 12, memory module with each peripheral module 13rd, clock module 14 and the interface of communication module 15, data and the instruction of each peripheral module are received and sent, coordinate each outer boxing Normal work between block.

Preferably due to the battery powered mode of saliva impedance detection device, should when selecting the model of microprocessor chip Its low power capabilities of high spot reviews on the premise of requirement is met.Compare through multi-party, the utility model selection texas,U.S Main control chips of the MSP430F149 of instrument (TI) as system, the microprocessor chip are at the mixed signal of a 16 Manage chip.MSP430 series monolithics are famous with low-power consumption, and it is internally integrated outside numerous analog circuits, digital circuit etc. Functional module is enclosed, disclosure satisfy that the processing of analog and digital signal.Microprocessor control circuit includes microprocessor and periphery electricity Shown in such as Figure 13 (a) of road, including：

Single-chip microcomputer, the XIN pins of single-chip microcomputer are connected with XOUT/TCLK pins by crystal oscillator Y3, crystal oscillator Preferably 32.768MHZ, digital power pin DVcc meet digital power+3.3V, and the digital power pin is also connect by electric capacity C19 Ground, electric capacity C19 capacitance is preferably 0.1uF, and analog power pin AVcc meets digital power+3.3V, the analog power pin AVcc is also grounded by electric capacity C18, and electric capacity C18 capacitance is preferably 0.1uF, digitally with simulation ground common ground, XT2IN pins are connected with XT2OUT pins by crystal oscillator Y2, and crystal oscillator Y2 is preferably 8MHZ, the crystal oscillation Device is also connected with two electric capacity C16, C17 respectively, and the capacitance of two electric capacity is equal, it is preferable that is 33pF；

Figure 13 (b) is referred to, for a test device, for completing the close beta of single-chip microcomputer, 1 pin for testing device connects The TDO/TD1 pins of single-chip microcomputer, 3 pins connect the TDI pins of single-chip microcomputer, and 5 pins connect the TMS pin of single-chip microcomputer, 7 pin order pieces The TCK pin of machine, 11 pins connect single-chip microcomputer/ NIMI pins, 9 pins ground connection, digital power pin connect+3.3V voltages.

Figure 14 is referred to, Figure 14 is the structural representation of analog signal processing module in the utility model embodiment.

As shown in figure 14, analog signal processing module 9 includes amplifying circuit 91, phase-sensitive detection circuit 92, voltage follow electricity Road 93, VCC/2 voltage follower circuits 94 and phase sensitive detection signal processing circuit 95；

Amplifying circuit 91, for being amplified to the voltage signal of analog quantity, the voltage signal being amplified；

Phase-sensitive detection circuit 92, for carrying out phase sensitive detection to the voltage signal of amplification, phase sensitive detection signal is obtained, and it is defeated Enter voltage follower circuit 93；Phase sensitive detection signal includes two-way voltage signal；

Voltage follower circuit 93, for carrying out buffering isolation to the two-way voltage signal in phase sensitive detection signal, and input Phase sensitive detection signal processing circuit；

VCC/2 voltage follower circuits 94, for producing VCC/2 voltages, and input phase sensitive detection signal processing circuit 95；

Phase sensitive detection signal processing circuit 95, for the two paths of signals in phase sensitive detection signal and VCC/2 voltage signals Merge and filtering process, and export.

As shown in figure 15, amplifying circuit 91 includes preamplifying circuit 910 and rear class amplifying circuit 911：Prime amplification electricity Road 910, for carrying out anti-phase amplification to the voltage signal of analog quantity, obtain the amplification with the voltage signal opposite in phase of analog quantity Voltage signal；Rear class amplifying circuit 911, for carrying out anti-phase amplification to amplification voltage signal, obtain the voltage signal of analog quantity Amplified signal.

After saliva impedance detection probe is put into oral cavity, a measuring loop can be formed, is measured by collection voltages Point is that the magnitude of voltage formation voltage signal of the voltage at saliva impedance both ends can obtain friendship of the exciting signal source after resistance R partial pressures Flow square-wave signal.Ac square wave signal is bipolar signal, and distorted signals can be produced by being handled under single supply electric power thus supplied, therefore Need ac square wave signal being converted to direct current signal, and AC signal is amplified into certain multiple to facilitate subsequent treatment.This reality With new preferably integrated amplifier chip LMV324 come Design enlargement circuit.Integrated operational amplifier LMV324 uses cmos circuit knot Structure, for the low energy-consumption electronic device of single supply power supply, its voltage range is 2.7V~5.0V；Track to track operation can improve integrated computation and put The signal to noise ratio of big device；Ultralow quiescent current, it is suitable for the equipment of portable cell power supply.Set based on integrated transporting discharging chip LMV324 The preamplifying circuit of meter is as shown in figure 16.

As shown in figure 16, preamplifying circuit 910 includes：

First integrated operational amplifier AR1；

First integrated operational amplifier AR1 in-phase input end is connected with the first bleeder circuit,

First bleeder circuit includes the resistance R3 and resistance R4 of series connection, and resistance R3 one end is connected with voltage VCC, resistance R3 The other end be connected respectively with resistance R4 one end and the first integrated operational amplifier AR1 in-phase input end, resistance R4's is another One end is grounded, and power supply VCC inputs the first integrated operational amplifier AR1 in-phase input end after resistance R3 partial pressures；Resistance R4's Both ends also one electric capacity C2 of parallel connection, noise reduction is filtered to the input voltage of the first integrated operational amplifier AR1 in-phase input ends；Its In, R3=R4, thus the partial pressure value of in-phase input end access is VCC/2, it is the exchange side for exporting exciting signal source that it, which is acted on, Ripple signal Sample_Signal direct current biasings make the first integrated operational amplifier AR1 output signals be converted to direct current to VCC/2 Signal.First integrated operational amplifier AR1 inverting input series resistance R1 and electric capacity C1, resistance R1 connect with exciting signal source Connect, also connect a resistance R2 between the first integrated operational amplifier AR1 inverting input and output end.

Electric capacity C1 main function is blocking circulation exchange, isolates the Sample_Signal signals of exciting signal source output The DC influence component of introducing, the DC component in anti-stop signal have an impact after being exaggerated to measurement result.But for difference The ac square wave signal of frequency, electric capacity C1 equivalent characteristic also differ.Due to excitation exchange letter in the utility model embodiment Number source uses excitation alternating message source of the frequency for 180Hz, therefore calculates by actual model and emulation, for this practicality newly 180Hz excitation alternating message source in type, the influence very little of electric capacity C1 capacitive reactance to circuit, electric capacity C1 can be equivalent to exchange Signal shorts.Resistance R1, R2 are connected to the first integrated operational amplifier AR1 inverting input in above-mentioned preamplifying circuit, For being amplified to the ac square wave signal that exciting signal source exports, multiplication factor A=-R2/R1.

The output signal Signal_Offset of preamplifying circuit is direct current biasing to VCC/2 and by exchange side in Figure 16 Composite signal after ripple signal Sample_Signal amplifications, and its AC compounent phase and ac square wave signal are anti-phase.For just In carrying out follow-up phase sensitive detection processing, it is necessary to change the phase of Signal_Offset signal communication components again, believe output Number with the former same phase of Sample_Signal signals.The rear class amplifying circuit of the utility model design is as shown in figure 17, and sets phase The multiplication factor answered suitably adjusts the amplitude of signal.

As shown in figure 17, rear class amplifying circuit 911 includes：

Second integrated operational amplifier AR2；

Second integrated operational amplifier AR2 in-phase input end is connected with the second bleeder circuit, and the second bleeder circuit includes The resistance R3 ' and resistance R4 ' of series connection, resistance R3 ' one end are connected with voltage VCC, the resistance R3 ' other end respectively with resistance R4 ' one end connects with the second integrated operational amplifier AR2 in-phase input end, resistance R4 ' other end ground connection, power supply VCC The second integrated operational amplifier AR2 in-phase input end is inputted after resistance R3 ' partial pressures；Resistance R4 ' the both ends also electricity of parallel connection one Hold C2 ', noise reduction is filtered to the input voltage of the second integrated operational amplifier AR2 in-phase input ends；Wherein, R3 '=R4 ', Thus the magnitude of voltage of the second integrated operational amplifier AR2 in-phase input ends access is the magnitude of voltage VCC/2 after partial pressure, and its effect is By the ac square wave signal Sample_Signal direct current biasings of exciting signal source output to VCC/2, amplify the second integrated computation Device AR2 output signals are converted to direct current signal.

Second integrated operational amplifier AR2 inverting input series resistance R1 ', resistance R1 also with preamplifying circuit Output end connects, and the second integrated operational amplifier AR2 inverting input is also connected to the second integrated computation by resistance R2 ' and put Big device AR2 output end is to form negative feedback loop；

Due to preamplifying circuit output signal Signal_Offset for direct current biasing to VCC/2 and by ac square wave Composite signal after signal Sample_Signal amplifications, thus the alternating component in composite signal is handled without handling direct current Component VCC/2 is, it is necessary to which the in-phase input end in the second integrated operational amplifier accesses VCC/2.Resistance R3 '=R4 ' is made, can be with The magnitude of voltage for obtaining the access of the second integrated operational amplifier in-phase input end is VCC/2, can according to the empty short principle of discharge circuit To obtain the voltage of integrated operational amplifier inverting input also as VCC/2.Resistance R1 ', R2 ' are connected to integrated operational amplifier Inverting input, for realize alternating component in amplifying circuit output signal Signal_Offset amplitude amplify and phase Bit Inverting, it is A=-R2 '/R1 ' that it, which exchanges multiplication factor,.The output signal Signal_to_SW of anti-phase operational amplification circuit is straight Stream is biased to VCC/2 and by the composite signal after alternating component amplification in Signal_Offset signals, and its AC compounent Phase and the same phase of Sample_Signal signals.

Ac square-wave voltage caused by exciting signal source is applied to induction electrode both ends, the equivalent resistance Rs of saliva and double electricity Layer capacitance Cd forms a passage, and wire Distributed Capacitance Cp also forms a passage.If the impedance of solution to be measured is higher, with Cause electric double layer capacitance Cd capacitive reactance sufficiently small, can be ignored, then can be equivalent to ac square wave signal and pass through a resistance The circuit in parallel with an electric capacity, as shown in figure 18.Ac square wave signal does not produce phase shift by resistance Rs, and passes through lead point Cloth electric capacity Cp can produce 90 ° of phase shift.According to this feature of measuring circuit, using phase sensitive detection principle, swash using with inputting The switching signal that source signal is encouraged with phase controls rectification circuit, will be converted into pure exchange by wire Distributed Capacitance Cp signal all the way Signal, and by resistance Rs signal all the way relative to driving source without phase shift, normal rectification, then believe by LPF, exchange Number it is filtered out, i.e. the influence of wire Distributed Capacitance Cp is eliminated.The DC component obtained after filtering and saliva equivalent resistance Rs It is relevant, therefore saliva impedance can be obtained by output DC quantity.

In Figure 18, excitation alternating message source is connected to saliva solution by divider resistance R, because saliva can be equivalent to figure Middle wire Distributed Capacitance Cp and solution resistance Rs, excitation exchange source signal produce two paths of signals when passing through saliva, and signal leads to all the way 90 ° of wire Distributed Capacitance Cp and phase shift are crossed, signal does not produce phase shift by solution resistance Rs all the way in addition, therefore voltage is surveyed The voltage signal of amount point is the signal by electric capacity Cp and the superposed signal by solution resistance Rs signals.And the utility model master What is measured is saliva resistance Rs value, it is necessary to pass through electric capacity Cp component of signal to the target signal filter of voltage measurement point, extraction Resistance value Rs is converted to by saliva resistance Rs signal, then by corresponding signal value.The phase of the utility model embodiment Quick detecting circuit has identification signal phase and the ability of frequency-selecting, can extract useful letter according to the phase difference between signal Number, apply to the phase difference signal detection method of saliva impedance detection of the present utility model.Therefore, the utility model uses phase sensitivity Detecting circuit eliminates the component of signal by wire Distributed Capacitance Cp, useful signal that extraction passes through saliva resistance Rs.

Phase-sensitive detection circuit determines that the degree of accuracy of measuring system and Testing of Feeble Signals are horizontal, plays and suppresses noise and phase The function of position detection, its circuit implementations have a variety of, such as diode bridge phase sensitive detection, analog switch phase sensitive detection.Due to Analog switch LVC4066D switching characteristics are good, small power consumption, and phase sensitive detection is realized with it, and circuit structure is simple, element is few, debugging It is convenient.Therefore, the utility model forms phase-sensitive detection circuit, analog switch LVC4066D using cmos analog switch LVC4066D Pin distribution it is as shown in figure 19.

Typical analog switch phase-sensitive detection circuit is as shown in figure 20.Square-wave signal caused by exciting signal source passes through one Phase inverter produces the symmetrical square wave of two opposite in phase, control two groups of switches TG1, TG3 and TG2, TG4 alternating break-makes.Encouraging The positive half cycle of signal source is made as high level, analog switch TG1 and TG3 conducting, TG2 and TG4 shut-offs with phased, equivalent to CH3_IN + 90 ° of input signals of phase difference are connected, the signal is through subsequent amplification circuitry with mutually amplification；CH4_IN+ connects in-phase input signals for 1, The signal is through the anti-phase amplification of subsequent amplification circuitry.In the negative half period of driving source low level, on off state and just half are made as with phased Week, TG2 and TG4 conductings, equivalent to CH3_IN+ connection in-phase input signals for 1, the signal was after on the contrary, becoming TG1 and TG3 shut-offs Continuous amplifying circuit is the same as mutually amplification；CH4_IN+ connects 90 ° of input signals of phase difference, and the signal is through the anti-phase amplification of subsequent amplification circuitry. It was found from above-mentioned analysis, pass through with exciting signal source phase identical with the input of phase control signal at switching detection and amplifying circuit Equivalent to full-wave rectification after reason, DC component is filtered to obtain；And with the signal input of 90 ° of exciting signal source phase difference by switch inspection What is obtained after ripple and amplifying circuit processing is still AC signal, without DC component in signal, can be eliminated after filtering.

Phase sensitive detection method filters out the voltage signal by wire Distributed Capacitance Cp, makes wire Distributed Capacitance to output DC quantity Do not contribute, output DC quantity is only relevant with solution resistance Rs, i.e., relevant with solution resistance rate, so as to eliminate lead distribution electricity The influence of appearance.The circuit structure of analog switch phase sensitive detection is as shown in figure 21, including：

Analog switch 920, the phase-shift circuit 921 being connected respectively with analog switch 920 and negative circuit 922, negative circuit 922 input signal is control signal in the same direction, and the inverted circuit 922 of control signal in the same direction obtains an inverted control signal with defeated Enter analog switch 920, the input signal of phase-shift circuit is in-phase input signals for 1, and in-phase input signals for 1 carries out phase through phase-shift circuit Move, obtain the input signal of analog switch 920 to input analog switch 920.

Wherein, negative circuit 922 includes：Resistance R5, resistance R6, diode T1, triode Q1 and resistance R7, in the same direction control After signal series resistance R5, it is grounded by resistance R6, and is connected with triode Q1 respectively, after triode Q1 series diodes T1 Ground connection, triode Q1 are also connected with resistance R7, and power supply VCC series resistances R7 is connected after carrying out partial pressure with triode Q1, resistance R7 Connecting node between triode Q1 is connected to analog switch 920；Triode Q1 base stage connects with resistance R5 and resistance R6 Connect, be grounded after triode Q1 emitter stage series diode T1, triode Q1 colelctor electrode is connected with resistance R7, triode Q1's Colelctor electrode is also connected with analog switch 920.

Phase-shift circuit 921 includes resistance R8 and electric capacity C3, and analog switch 920 is connected with resistance R8, analog switch 920 and electricity Resistance R8 is also connected with electric capacity C3, electric capacity C3 ground connection.Resistance R8 resistance is：0~100k, preferably 10k；Electric capacity C3 capacitance is：0 ~10uf, preferably 1uf.It should be noted that resistance R8 and electric capacity C3 are worth without border 0.

Wherein, SW_Control_Signal signals are the same phase control signal of analog switch, through resistance R5, R6, R7, two Pole pipe T1 and triode Q1 produces the control signal of an opposite in phase；Signal_to_SW signals amplify for amplifying circuit The signal exported afterwards, the in-phase input signals for 1 as analog switch input analog switch, and one is produced through electric capacity C3 and resistance R8 The input signal that 90 ° of phase shift.

Output after the processing of analog switch LVC4066D phase-sensitive detection circuits is analog voltage signal.Consider processing simulation electricity The continuity of the security of signal, convenience, anti-interference and output signal is pressed, in order to reduce the loss of signal and signal Distortion, this utility model embodiment provide a kind of voltage follower circuit and enter row buffering to output signal.Voltage follower circuit Input voltage is identical with output voltage, and its effect is as follows：

Voltage follower input resistance is big, can separate voltage follower front and back stages, allow prime not by successive load The influence of size, the multiplication factor of prime or other performance can be kept constant, serve the isolation to prime signal, buffering is made With；Output resistance is small, and driving force is strong, improves carrying load ability, while signal can be made rapidly to transmit, and reduces and is fed back in circuit The interference of signal.The input impedance of voltage follower is high, the low feature of output impedance, can extremely go to understand：When input hinders When anti-very high, it is equivalent to open a way to front stage circuits；When output impedance is very low, a constant pressure is equivalent to late-class circuit Source, i.e. output voltage be not by late-class circuit impedance influences.One to front stage circuits equivalent to open circuit, output voltage and not by rear class The circuit of impedance influences possesses buffer action certainly, even if being independent of each other between forward and backward level circuit.The electricity of the utility model design Pressure follows circuit as shown in figure 22.

Voltage follower circuit 93 includes：

3rd integrated operational amplifier AR3, the 3rd integrated operational amplifier AR3 in-phase input end are connected with resistance R9, 3rd integrated operational amplifier AR3 inverting input is connected to the 3rd integrated operational amplifier AR3 output by resistance R10 End；

4th integrated operational amplifier AR4, the 4th integrated operational amplifier AR4 in-phase input end are connected with resistance R12, Resistance R12 series resistances R11, the 4th integrated operational amplifier AR4 inverting input are connected to the 4th collection by resistance R13 Into operational amplifier A R4 output end；

Shunt capacitance C4 between 4th integrated operational amplifier AR4 two inputs, the output of phase-sensitive detection circuit 92 Signal shunt capacitance C4 after resistance R11 partial pressures.

Wherein, as shown in figure 23, VCC/2 voltage follower circuits 94 include：

5th integrated operational amplifier AR5,

Power supply VCC is connected to the 5th integrated operational amplifier AR5 in-phase input end, the 5th integrated fortune by resistance R14 The in-phase input end for calculating amplifier is also grounded by resistance R15, and the inverting input of the 5th integrated operational amplifier passes through resistance R16 is connected to the 5th integrated operational amplifier AR5 output end.

Wherein, as shown in figure 24, phase sensitive detection signal processing circuit 95 includes：

6th integrated operational amplifier AR6；

The output voltage of voltage follower circuit 93 and VCC/2 voltage follower circuits 94 passes through resistance R19 and resistance R20 respectively The 6th integrated operational amplifier AR6 in-phase input end is connected to after partial pressure, the output voltage of voltage follower circuit 93 passes through electricity The 6th integrated operational amplifier AR6 inverting input is connected to after resistance R17 partial pressures, the 6th integrated operational amplifier AR6's is anti- Phase input is also connected to the 6th integrated operational amplifier AR6 output end, the 6th integrated operational amplifier by resistance R18 AR6 output end is connected with low-pass filter circuit 950, and low-pass filter circuit 950 is used to enter the output voltage signal of output end Row LPF.

Preferably, low-pass filter circuit 950 includes：

Resistance R21, one end are connected to the 6th integrated operational amplifier AR6 output end, and other end series capacitance C5 is followed by Ground.

Voltage follower circuit 93 realizes the buffering buffer action of two paths of signals, in order to ensure the anti-dry of the pending signal of two-way Immunity, two voltage followers input and meet a filter capacitor C4, and the input of a voltage follower wherein Connect a resistance R11.Electric capacity C4's and resistance R11 act as：Filter capacitor C4 connects two paths of signals, forms signal transmission Coupling circuit, the differential signal between two paths of signals are a steady state values, and filter capacitor C4 can filter out this constant difference letter High-frequency noise on number, spike burr etc., allows two paths of signals to be independent of each other, and eliminates DM EMI noise.If two-way is believed Have in number line it is any be interfered all the way, interference can be eliminated by the filter capacitor C4 of bridging.R11 is coupled back into for transmission in figure The series resistance on road, it act as the electric current of limit circuit.Voltage follower, because of the spy that its input resistance is big, output resistance is small Point, buffering and the isolation of front stage signal can be realized, allows prime not influenceed by successive load size.Voltage follower plays The effect formed a connecting link, the intergrade of casacade multi-amplifier can be done, impedance conversion can be carried out, make to realize between amplifier front stage Impedance matching.

In the introduction of foregoing amplifying circuit, in order to facilitate the AC signal that collects of processing, this is believed in circuit Number being biased to VCC/2 DC voltages is handled.Still need to use reference voltage level during because of follow-up calculating signal amplitude VCC/2, to ensure the precision of measurement result, it is necessary to reduce the interference of reference power source, improve the quality and stability of reference power source. The utility model realizes that VCC/2 reference power sources design using voltage follower circuit, and its circuit is as shown in figure 23.

Figure 23 is refer to, VCC/2 voltage follower circuits 94 include：5th integrated operational amplifier AR5, input power VCC The 5th integrated operational amplifier AR5 in-phase input end is connected to by resistance R14, the 5th integrated operational amplifier AR5's is same Phase input is also grounded by resistance R15, and the 5th integrated operational amplifier AR5 inverting input and the 5th integrated computation amplify Connect a resistance R16 between device AR5 output end.

The output after voltage follower circuit buffering of the two paths of signals of phase-sensitive detection circuit output is CH3_OUT and CH4_ OUT, but to calculate final saliva impedance Rs, it is also necessary to two-way output signal is further processed.Due to excitation Signal source is identical with in-phase input signals for 1 phase, is made as high level with phased in the positive half cycle of exciting signal source, CH3_OUT is phase 90 ° of input signals of potential difference, CH4_OUT is in-phase input signals for 1；Low level is made as with phased in the negative half period of exciting signal source, CH3_OUT is in-phase input signals for 1, and CH4_OUT is 90 ° of input signals of phase difference.The operation amplifier electricity designed according to two paths of signals Road is as shown in figure 24, wherein the in-phase input end of CH3_OUT and VCC/2 signals access amplifier, CH4_OUT signals access amplifier Inverting input.Circuit output signal Vout calculation formula is：

Vout=(V_CH3-V_CH4)+VCC/2

V in formula_CH3For the output voltage values of CH3_OUT signals, V_CH4For the output voltage values of CH4_OUT signals.By upper That states formula can be calculated output signal Vout (i.e. MCU_Signal), can be inputted after carrying out analog-to-digital conversion process to the signal Processor 11 carries out computing.

In the foregoing circuit of the utility model embodiment, the power supply of analog signal processing circuit has digital power also to have simulation Power supply, therefore, the utility model embodiment provide a kind of power supply circuit, are powered for saliva impedance detection device.

As shown in figure 25, power supply circuit 16 includes：Power module 160 and mu balanced circuit 162；

As shown in figure 26, mu balanced circuit 162, including：Voltage stabilizing module 1620, the output of its input and power module 160 End connection, output end are connected with signal transacting mainboard 161；Filter capacitor C6 and electric capacity C7 in parallel, the circuit on one side after parallel connection It is connected with the output end of power module 160, other end ground connection；Filter capacitor C8 in parallel and electric capacity C9, the circuit one after parallel connection End is connected with the output end of Voltage stabilizing module 1610, other end ground connection；Or filter capacitor C8, electric capacity C9 and electric capacity C10 in parallel, electricity Hold C10 to be arranged between electric capacity C8 and electric capacity C9, the circuit on one side after parallel connection is connected with the output end of Voltage stabilizing module 1610, another End ground connection.

Wherein, power supply circuit 16 also includes isolation circuit 163, and its input is connected with the output end of Voltage stabilizing module 1620, Its output end is connected with the input of the analog signal processing module 9 on signal transacting mainboard 161.Isolation circuit 163 is electric capacity Inductor filter network, including：The inductance L1 of series connection, its input are connected with the output end of Voltage stabilizing module 1620, its output end with The input connection of analog signal processing module 9 on signal transacting mainboard 161；Electric capacity C11 and electric capacity C12 in parallel, it is in parallel Circuit on one side afterwards is connected with the output end of Voltage stabilizing module 1610, and another termination is digitally；Electric capacity C13 and electric capacity C14 in parallel, Circuit on one side after parallel connection is connected with inductance L1, another termination simulation ground；Digitally connected with simulation by resistance R22.Electricity It is polarity free capacitor to hold C11, electric capacity C12, electric capacity C13, electric capacity C14.Electric capacity C11 capacitance scope is the μ F of 0.01 μ F~1；With/ Or electric capacity C12 capacitance scope is the μ F of 0.01 μ F~1；And/or electric capacity C13 capacitance scope is the μ F of 1 μ F~10；And/or electric capacity C14 capacitance scope is the μ F of 0.01 μ F~1.

Preferably, filter capacitor C6 is polar capacitor, and the output end of its positive pole and power module connects, negative pole ground connection；With/ Or filter capacitor C8 is polar capacitor, the output end of its positive pole and Voltage stabilizing module connects, negative pole ground connection；And/or electric capacity C7, electric capacity C9, electric capacity C10 are polarity free capacitor.

It is further preferable that filter capacitor C6 capacitance scope is the μ F of 100 μ F~1000；And/or filter capacitor C8 capacitance Scope is the μ F of 100 μ F~1000；And/or electric capacity C7 capacitance scope is the μ F of 0.01 μ F~1；And/or electric capacity C9 capacitance scope For the μ F of 0.01 μ F~1；And/or electric capacity C10 capacitance scope is the μ F of 1 μ F~10.

Wherein, the output end voltage value of power module 160 is 6V or 4.3V.The output end voltage value of Voltage stabilizing module 162 is 3.3V。

Wherein, power module 160 is made up of 4 No. 5 batteries of section, and DC voltage value is 6V after the series connection of 4 batteries, is at signal Manage mainboard 161 and power supply is provided.6V voltage conversions are 3.3V voltages by mu balanced circuit 162 on signal transacting mainboard 161, are directly Digital power electricity consumption module 165 on signal transacting mainboard 161 is powered or digital power is converted into mould by isolation circuit 163 Intend power supply, be that the analog signal processing module 9 on signal transacting mainboard 161 provides analog power.The output end of power module 160 It is connected with the input of the Voltage stabilizing module 1610 on signal transacting mainboard 161, as saliva onset of ovulation detection device power input. Power module 160 is connected by power cable with the Voltage stabilizing module 1610 on signal transacting mainboard 161, and electricity is realized by controlling switch The supply and shut-off in source.

The main control chip of Voltage stabilizing module is ME6211 series voltage stabilizing chips, can realize high Ripple Suppression, low output noise, The excellent properties of super fast response and low voltage difference.Preferably, the concrete model of ME6211 series voltage stabilizing chip is ME6211C33.

In order to be better understood from the utility model, the ME6211 series voltage stabilizing chip that the utility model is selected is carried out below Describe in detail.

ME6211 series voltage stabilizing chips are the high-precision linear voltage-stablizers manufactured with CMOS technology, its built-in fixed reference Voltage source, error correcting circuit, current-limiting circuit, phase compensating circuit and the MOSFET of low internal resistance, high ripple suppression can be realized System, the excellent properties of low output noise, super fast response and low voltage difference.The high-speed response characteristic energy of ME6211 series voltage stabilizing chips The fluctuation of load current is dealt with, is particularly suitable for using battery powered equipment, its technical parameter is as shown in table 3.

The LDO linear voltage regulator ME6211 series technique parameter lists of table 3

Concrete model in the present embodiment from voltage stabilizing chip is ME6211C33, referring to Figure 26, Figure 27, power module 160 Output end connection Voltage stabilizing module input, through voltage stabilizing chip ME6211C33 export 3.3V voltages be signal transacting mainboard 161 Each module for power supply.Voltage stabilizing chip ME6211C33 output voltage quality can be evaluated with two parameter indexs：One parameter It is the ripple size of output voltage, illustrates fluctuation situation of the voltage stabilizing chip output voltage under a certain steady state value, namely direct current is defeated Go out the AC signal composition included in voltage signal, AC signal composition amplitude is bigger, illustrates that output voltage quality is poorer, instead It, then better, corresponding voltage stabilizing chip technical parameter is PSRR (Ripple Suppression ratio).Another parameter is steady for VD Qualitative, i.e., output voltage keeps the stability of a certain steady state value, and voltage stabilizing chip can make defeated with other factors such as the rises of temperature Go out voltage to drift about, mainly there are two parameters to be weighed：Voltage stabilizing chip temperature stability parameters and voltage stabilizing chip are steady for a long time Qualitative parameter.

The parameter for influenceing the output voltage ripple size of Voltage stabilizing module has two：One parameter is ME6211C33 voltage stabilizing cores The input voltage quality of piece, the quality of input voltage signal can influence the stability of output voltage.Another parameter is steady Rejection ability of the chip to input voltage signal fluctuation in itself is pressed, corresponding technical parameter is the Ripple Suppression ratio of voltage stabilizing chip PSRR.From special analog voltage oscilloscope measurement, power module 1 is by the 4 6V output voltages that are composed in series of No. 5 batteries of section Ripple amplitude Vripple_in=± 20mv.And the output voltage of power module 1 need to be defeated after shunt capacitance is filtered Enter into Voltage stabilizing module, therefore the ripple amplitude of the input terminal voltage of Voltage stabilizing module can be less than 20mv, the present embodiment temporarily presses this Numerical computations.By that can be obtained in table 4, the Ripple Suppression of ME6211C33 voltage stabilizing chips takes 75dB than PSRR representative value, by dependency number Value bring into Ripple Suppression than calculation formula in obtain Vripple_out=± 0.003mv.

PSRR is can be seen that from formula being above one and be used for describing the amount that output signal influenceed by power supply, PSRR values are got over Greatly, output voltage signal is influenceed smaller by power supply.The ripple of power input voltage is smaller, the Ripple Suppression ratio of voltage stabilizing chip Higher, the ripple of output voltage is smaller, and signal quality is better.Result of calculation illustrates voltage stabilizing chip to input voltage in the present embodiment Ripple Suppression it is preferable, output voltage meet require.

The stability of VD mainly has two parameters to be weighed, be voltage stabilizing chip temperature stability parameters and Voltage stabilizing chip long-time stability parameter.Inquire about ME6211C33 voltage stabilizing chips datasheet data explanation, voltage stabilizing chip it is low Temperature drift parameter is 50ppm/ DEG C, and its implication is that voltage stabilizing chip temperature often rises 1 DEG C of output voltage value changes 50/1000000. The output voltage of Voltage stabilizing module is 3.3V, thus calculates voltage stabilizing chip temperature and often rises 1 DEG C of its output voltage value changes 0.165mv, this temperature drift amount can be ignored.For voltage stabilizing chip long-time stability parameter, it is contemplated that saliva is ovulated The start time of measuring magnitude of phase detection device does not have comparativity therewith, can not consider voltage stabilizing chip long-time stability parameter pair Influenceed caused by measurement result.Actual test also demonstrates that the performance of Voltage stabilizing module meets requirement of the present utility model.

Figure 27 is referred to, Figure 27 is the second embodiment for the power supply circuit that the utility model embodiment provides.

As shown in figure 27, in the present embodiment, on the basis of the embodiment shown in Figure 26, mu balanced circuit also includes Electric capacity C10, electric capacity C10 are in parallel with electric capacity C8 and electric capacity C9 respectively, and its position is arranged between electric capacity C9 and C9, after in parallel Circuit on one side and Voltage stabilizing module output end connect, the other end ground connection.

Further, electric capacity C10 is polarity free capacitor.

Further, electric capacity C10 capacitance scope is the μ F of 1 μ F~10.Preferably, electric capacity C10 capacitance is 1 μ F.

Present embodiment is further caused to have the beneficial effect that on the basis of first embodiment：Due to capacitance not Together, the frequency range filtered is different, and one electric capacity C10 of multi-parallel, filter effect is more preferable, can further improve the defeated of mu balanced circuit Go out quality of voltage.

Figure 28 is referred to, Figure 28 is the 3rd embodiment of power supply circuit provided by the utility model.The present embodiment is in reality Apply and add isolation circuit 163 on the basis of example 1.

Analog signal processing module 9 on signal transacting mainboard 161 is that the analog signal of voltage measurement point collection is carried out Processing, the working characteristics of the module is higher to the stability of power supply, quality requirement, to reduce other modules in circuit Power supply disturbance, single analog power should be provided as far as possible.Therefore analog power and digital power, which will separate, isolates, and then passes through By simulating and digitally single-point connects together for thin wiring.Because digital signal change speed is fast, so as to draw on digitally Play very big noise；The relative change of analog signal is slow, it is necessary to which a clean reference ground is operated, therefore obstructs number as far as possible The noise on word ground channels to simulation ground.If simulating ground and digitally mixing, noise just influences whether the quality of analog signal. The power supply of most of operational module is digital power in signal transacting mainboard 161, directly can be connected with the output end of Voltage stabilizing module, And the power supply that analog signal processing module 9 uses is analog power, therefore need to be isolated.

Figure 29 is referred to, the power supply circuit also includes isolation circuit 163, the input and Voltage stabilizing module of isolation circuit 163 Output end connection, the output end of isolation circuit 163 is connected with the input of analog signal processing module 9.Voltage stabilizing module it is defeated It is analog power to go out the digital power that end exports to export by isolation circuit 163, is powered for analog signal processing module 9.

In the present embodiment, isolation circuit 163 is capacitor and inductor filter network, includes the inductance L1 of series connection, input with it is steady The output end connection of die block, output end are connected with the input of the analog signal processing module 9 on signal transacting mainboard 161； Electric capacity C11 and electric capacity C12 in parallel, the output end of circuit on one side and Voltage stabilizing module after parallel connection connect, and another termination is digitally； Electric capacity C13 and electric capacity C14 in parallel, the circuit on one side after parallel connection are connected with inductance L1, another termination simulation ground；Digitally and mould Intend ground to connect by resistance R22.

Further, it is preferred that inductance L1 inductance value is 22 μ H.Inductance is path to direct current, the exchange to certain frequency Signal has barrier effect, so series inductance prevents the AC influence composition in signal from passing to rear class in circuit, so as to quilt Capacitance short-circuit enters ground.

Further, electric capacity C11, electric capacity C12, electric capacity C13, electric capacity C14 are polarity free capacitor, have blocking circulation exchange The indirect electric capacity of function, in circuit signal and ground, can enter ground by the AC influence composition short circuit in signal.

Further, electric capacity C11 capacitance scope is the μ F of 0.01 μ F~1.Preferably, electric capacity C11 capacitance is 0.1 μ F.

Further, electric capacity C112 capacitance scope is the μ F of 0.01 μ F~1.Preferably, electric capacity C12 capacitance is 0.1 μ F.

Further, electric capacity C13 capacitance scope is the μ F of 1 μ F~10.Preferably, electric capacity C13 capacitance is 1 μ F.

Further, electric capacity C14 capacitance scope is the μ F of 0.01 μ F~1.Preferably, electric capacity C14 capacitance is 0.1 μ F.

Further, resistance R22 is simulation ground and tie point digitally, and R22 resistance is 0 Europe, and its function is to simulate Ground with digitally connected in single-point.

The stability of power module 1 is improved during in view of later product and reduces size, is replaced using 4.3V lithium batteries In generation, is by the 4 No. 5 6V power modules 1 formed of section.

As above, the power supply circuit uses the combination of parallel-capacitor circuit, and low-frequency ac interference signal and high frequency is miscellaneous Ripple short circuit enters ground, improves the working effect of filter capacitor.Mu balanced circuit in the power supply circuit passes through in the defeated of Voltage stabilizing module Enter end connection shunt capacitance to be filtered, improve the input voltage quality of voltage stabilizing chip, pass through the output end in Voltage stabilizing module Connection shunt capacitance is filtered, and further increases the output voltage quality of Voltage stabilizing module；Isolation electricity in the power supply circuit Road also leads to the function of direct current resistance exchange using inductance, and series inductance prevents the AC influence composition in signal from passing in circuit Rear class, so as to enter ground by capacitance short-circuit, reduce the power supply disturbance of other modules in circuit, be saliva onset of ovulation detection device Analog signal processing module in signal transacting mainboard provides the analog power of stable high quality.Power supply electricity of the present utility model Mu balanced circuit and isolation circuit in road, requirement of the key modules to supply voltage high quality in signal transacting mainboard is met, It ensure that the measurement accuracy and stability of saliva onset of ovulation detection device.

Analog signal processing module is that the analog signal gathered to voltage measurement point in Figure 24 is handled, in order to handle The subsequent arithmetic of device 11.The working characteristics of this module device is higher to the stability of power supply, quality requirement, to reduce electricity The power supply disturbance of other devices in road, single analog power should be provided as far as possible.In general, analog power block and numeral electricity Source block, which will separate, isolates, and then by thin wiring, by simulating and digitally single-point connects together.Digital signal change speed It hurry up, so as to cause very big noise on digitally；The relative change of analog signal is slowly, it is necessary to which a clean reference ground is carried out Work, therefore the noise of barrier digitally channels to simulation ground as far as possible.If simulating ground and digitally mixing, noise will shadow Ring the quality to analog signal.The power supply of most of device work is digital voltage DC+3.3V in system, and analog signal processing The voltage that module uses is analog voltage VCC, therefore needs to be isolated.

The utility model embodiment also provides a kind of saliva impedance detection equipment, including a kind of saliva impedance detection probe and Saliva impedance detection device, in addition to exciting signal source, pop one's head in and connect with saliva impedance detection, carried for saliva impedance detection probe For pumping signal.

Excitation alternating message source is ac square wave signal generator, and as shown in figure 30, it includes：7th integrated computation amplifies Device AR7, power supply, oscillating circuit and resistance R25；Power supply is connected to the 7th integrated operational amplifier AR7's after resistance R25 partial pressures Normal phase input end, the 7th integrated operational amplifier AR7 normal phase input end and the 7th integrated operational amplifier AR7 output end it Between also connect a resistance R24, resistance R25 and resistance R24 between power supply VCC and the 7th integrated operational amplifier AR7 output ends Voltage carry out partial pressure, reference voltage of the voltage obtained after partial pressure as the 7th integrated operational amplifier AR7 normal phase input ends； The supply voltage of ac square wave generator in Figure 30.

7th integrated operational amplifier AR7 normal phase input end is also connected and is grounded after a resistance R26；

7th integrated operational amplifier AR7 inverting input is connected with an oscillating circuit, and the 7th integrated computation of regulation is put The frequency of big device AR7 output end output current.

Wherein, oscillating circuit includes electric capacity C6 and resistance R23；Resistance R23 is series at the 7th integrated operational amplifier AR7's Between inverting input and output end, by amplifier AR7 output voltage control between VCC and 0；

7th integrated operational amplifier AR7 inverting input is grounded after being also connected with electric capacity C6.

Wherein, ac square wave signal generator also includes：Electric capacity C7, electric capacity C7 one end are connected with power supply, other end ground connection.

Wherein, resistance R23 and electric capacity C6 meets following formula：F=1/ (2*pi*R23*C6)；

In formula, f represents signal frequency, and pi represents pi, and R23 represents resistance R23 resistance, and C6 represents electric capacity C6 electricity Capacitance.Preferably, resistance R23 scope is 0-1000k；Preferably, electric capacity C6 scope is 0-10uf.

It is further preferable that resistance R23 value is 100k；Electric capacity C6 value is 0.1uf.

Preferably, resistance R25, resistance R24 and resistance R26 three ratio are：1:1:1.It is further preferable that resistance R25, Resistance R24 and resistance R26 scope is respectively：0-1000k, 0-1000k, 0-1000k.

It is further preferred that resistance R25, resistance R24 and resistance R26 value are respectively：100k, 100k, 100k.

Wherein, ac square wave signal generator also includes：Electric capacity C7, it is connected to the defeated of the 7th integrated operational amplifier AR7 Go out end, with the DC voltage component in isolation and amplifier voltage, obtain output signal AC_square_wave, and pass through analog signal Interface circuit 8 is inputted into analog signal processing module 9 and handled.

As described above, the exciting signal source of the utility model embodiment can produce the exchange side for detecting saliva impedance Ripple signal, by applying ac-excited signal source, influence of the polarity effect to saliva electrolyte solution impedance measurement can be reduced Degree, the accuracy of measurement of saliva electrolyte solution impedance is improved, saliva electricity can not be measured in the prior art so as to solve The problem of electrolyte solution impedance.

It should be appreciated that above-mentioned embodiment of the present utility model is used only for exemplary illustration or explains this reality With new principle, without forming to limitation of the present utility model.Therefore, without departing from spirit and scope of the present utility model In the case of any modification, equivalent substitution and improvements done etc., should be included within the scope of protection of the utility model.In addition, The appended claims for the utility model are intended to fall into scope and border or this scope and border Whole in equivalents changes and modifications example.

Claims (30)

1. a kind of saliva impedance detection device, it is characterised in that including analog signal interface circuit (8), analog signal processing mould Block (9), A/D modular converters (10) and processor (11)：

Analog signal interface circuit (8), for obtaining the analog voltage signal at the saliva impedance both ends collected, and send to mould Intend signal processing module (9)；

Analog signal processing module (9), it is connected with the analog signal interface circuit (8), for the analog voltage signal Pre-processed, obtain the voltage signal of pretreated analog quantity；

A/D modular converters (10), for carrying out analog-to-digital conversion to the voltage signal of the pretreated analog quantity, obtain numeral The voltage signal of amount is simultaneously sent to processor (11)；

Processor (11), it is connected with the A/D modular converters (10), for receiving the voltage signal of the digital quantity, and is based on Ohm's law is calculated the voltage signal of the digital quantity, obtains saliva impedance.

2. saliva impedance detection device as claimed in claim 1, it is characterised in that analog signal processing module (9) bag Include amplifying circuit (91), phase-sensitive detection circuit (92), voltage follower circuit (93), VCC/2 voltage follower circuits (94) and phase sensitivity Rectified signal process circuit (95)；

Amplifying circuit (91), for being amplified to the voltage signal of analog quantity, the voltage signal being amplified；

Phase-sensitive detection circuit (92), for carrying out phase sensitive detection to the voltage signal of amplification, phase sensitive detection signal is obtained, and input The voltage follower circuit (93)；Phase sensitive detection signal includes two-way voltage signal；

Voltage follower circuit (93), for carrying out buffering isolation to the two-way voltage signal in phase sensitive detection signal, and input phase Quick rectified signal process circuit (95)；

VCC/2 voltage follower circuits (94), for producing VCC/2 voltages, and input the phase sensitive detection signal processing circuit (95)；

Phase sensitive detection signal processing circuit (95), for the two-way voltage signal in phase sensitive detection signal and VCC/2 voltages letter Number merge and filtering process and export.

3. saliva impedance detection device as claimed in claim 2, it is characterised in that the amplifying circuit (91) includes：

Preamplifying circuit (910), for carrying out anti-phase amplification to the voltage signal of the analog quantity, obtain and the analog quantity Voltage signal opposite in phase amplification voltage signal；

Rear class amplifying circuit (911), for carrying out anti-phase amplification to the amplification voltage signal, obtain the voltage of the analog quantity The amplified signal of signal.

4. saliva impedance detection device as claimed in claim 3, it is characterised in that the preamplifying circuit (910) includes：

First integrated operational amplifier AR1；

First integrated operational amplifier AR1 in-phase input end is connected with the first bleeder circuit,

First bleeder circuit includes the resistance R3 and resistance R4 of series connection, and resistance R3 one end is connected with voltage VCC, and resistance R3's is another One end is connected with resistance R4 one end and the first integrated operational amplifier AR1 in-phase input end respectively, the resistance R4 other end Ground connection, power supply VCC input the first integrated operational amplifier AR1 in-phase input end after resistance R3 partial pressures；Resistance R4 both ends Also one electric capacity C2 of parallel connection, noise reduction is filtered to the input voltage of the first integrated operational amplifier AR1 in-phase input ends；

First integrated operational amplifier AR1 inverting input series resistance R1 and electric capacity C1, resistance R1 connect with exciting signal source Connect, also connect a resistance R2 between the first integrated operational amplifier AR1 inverting input and output end.

5. saliva impedance detection device as claimed in claim 3, it is characterised in that the rear class amplifying circuit (911) includes：

Second integrated operational amplifier AR2；

Second integrated operational amplifier AR2 in-phase input end is connected with the second bleeder circuit, and the second bleeder circuit includes series connection Resistance R3 ' and resistance R4 ', resistance R3 ' one end is connected with voltage VCC, and the resistance R3 ' other end is respectively with resistance R4's ' One end connects with the second integrated operational amplifier AR2 in-phase input end, and resistance R4 ' other end ground connection, power supply VCC is through resistance The second integrated operational amplifier AR2 in-phase input end is inputted after R3 ' partial pressures；Resistance R4 ' both ends also one electric capacity C2 ' of parallel connection, Noise reduction is filtered to the input voltage of the second integrated operational amplifier AR2 in-phase input ends.

6. saliva impedance detection device as claimed in claim 2, it is characterised in that the phase-sensitive detection circuit (92) includes：

Analog switch (920), the phase-shift circuit (921) being connected respectively with analog switch (920) and negative circuit (922), it is described The input signal of negative circuit (922) is control signal in the same direction, and it is anti-that the inverted circuit of control signal (922) in the same direction obtains one For phase control signal to input the analog switch (920), the input signal of the phase-shift circuit is in-phase input signals for 1, described same Phase input signal carries out phase shift through the phase-shift circuit, obtains analog switch (920) input signal to input the analog switch (920)。

7. saliva impedance detection device as claimed in claim 6, it is characterised in that

The negative circuit (922) includes：

Resistance R5, resistance R6, diode T1, triode Q1 and resistance R7,

After the control signal series resistance R5 in the same direction, it is grounded respectively by resistance R6, and be connected with triode Q1, three pole It is grounded after pipe Q1 series diodes T1, the triode Q1 is also connected with resistance R7,

Power supply VCC series resistances R7 is connected after carrying out partial pressure with triode Q1, the connection between the resistance R7 and triode Q1 Node is connected to analog switch (920)；

The base stage of the triode Q1 is connected with resistance R5 and resistance R6, after the emitter stage series diode T1 of the triode Q1 Ground connection, the colelctor electrode of the triode Q1 is connected with resistance R7, the colelctor electrode of the triode Q1 also with the analog switch (920) connect.

8. saliva impedance detection device as claimed in claim 7, it is characterised in that

The phase-shift circuit (921) includes resistance R8 and electric capacity C3, the analog switch (920) are connected with resistance R8, the mould Intend switch (920) and the resistance R8 is also connected with electric capacity C3, the electric capacity C3 ground connection.

9. saliva impedance detection device as claimed in claim 2, it is characterised in that the voltage follower circuit (93) includes：

3rd integrated operational amplifier AR3, the in-phase input end of the 3rd integrated operational amplifier AR3 are connected with resistance R9, The inverting input of the 3rd integrated operational amplifier AR3 is connected to the 3rd integrated operational amplifier by resistance R10 AR3 output end；

4th integrated operational amplifier AR4, the in-phase input end of the 4th integrated operational amplifier AR4 are connected with resistance R12, The resistance R12 series resistances R11, the inverting input of the 4th integrated operational amplifier AR4 are connected to by resistance R13 The output end of the 4th integrated operational amplifier AR4；

Shunt capacitance C4 between two inputs of the 4th integrated operational amplifier AR4, the phase-sensitive detection circuit (92) Output signal after resistance R11 partial pressures shunt capacitance C4.

10. saliva impedance detection device as claimed in claim 2, it is characterised in that the VCC/2 voltage follower circuits (94) Including：

5th integrated operational amplifier AR5,

Power supply VCC is connected to the in-phase input end of the 5th integrated operational amplifier AR5, the 5th collection by resistance R14 In-phase input end into operational amplifier is also grounded by resistance R15, the inverting input of the 5th integrated operational amplifier The output end of the 5th integrated operational amplifier AR5 is connected to by resistance R16.

11. saliva impedance detection device as claimed in claim 2, it is characterised in that the phase sensitive detection signal processing circuit Including：

6th integrated operational amplifier AR6；

The output voltage of the voltage follower circuit (93) and VCC/2 voltage follower circuits (94) passes through resistance R19 and electricity respectively The 6th integrated operational amplifier AR6 in-phase input end, the output of the voltage follower circuit (93) are connected to after resistance R20 partial pressures Voltage is by being connected to the 6th integrated operational amplifier AR6 inverting input, the 6th integrated computation after resistance R17 partial pressures Amplifier AR6 inverting input is also connected to the 6th integrated operational amplifier AR6 output end, the 6th collection by resistance R18 Output end into operational amplifier A R6 is connected with low-pass filter circuit, and the filter circuit is used for the output voltage to output end Signal carries out LPF.

12. saliva impedance detection device as claimed in claim 11, it is characterised in that the low-pass filter circuit includes：

Resistance R21, one end are connected to the output end of the 6th integrated operational amplifier AR6, and other end series capacitance C5 is followed by Ground.

13. saliva impedance detection device as claimed in claim 1, it is characterised in that the saliva impedance detection device also wraps Include power supply circuit (16)；

The power supply circuit (16) includes：

Power module (160)；

Mu balanced circuit (162)；

The mu balanced circuit (162) includes：

Voltage stabilizing module (1620), its input are connected with the output end of the power module (160), output end and signal transacting master Plate (161) connects；

Filter capacitor C6 and electric capacity C7 in parallel, the circuit on one side after parallel connection is connected with the output end of power module (160), another End ground connection；

Filter capacitor C8 in parallel and electric capacity C9, the output end of circuit on one side and the Voltage stabilizing module (1620) after parallel connection connect Connect, other end ground connection；Or filter capacitor C8, electric capacity C8 in parallel and electric capacity C10, the electric capacity C10 are arranged at the electric capacity C8 Between electric capacity C9, the circuit on one side after parallel connection is connected with the output end of the Voltage stabilizing module (1620), other end ground connection.

14. saliva impedance detection device according to claim 13, it is characterised in that also including isolation circuit (163), its Input is connected with the output end of the Voltage stabilizing module (1620), and its output end is believed with the simulation on signal transacting mainboard (161) The input connection of number processing module (9).

15. saliva impedance detection device according to claim 14, it is characterised in that the isolation circuit is capacitor and inductor Filter network, including：

The inductance L1 of series connection, its input are connected with the output end of the Voltage stabilizing module (1620), its output end and signal transacting The input connection of analog signal processing module (9) on mainboard (161)；

Electric capacity C11 and electric capacity C12 in parallel, the circuit on one side after parallel connection are connected with the output end of the Voltage stabilizing module (1620), Another termination is digitally；

Electric capacity C13 and electric capacity C14 in parallel, the circuit on one side after parallel connection are connected with inductance L1, another termination simulation ground；

It is described digitally to be connected with the simulation by resistance R22.

16. saliva impedance detection device as claimed in claim 1, it is characterised in that the saliva impedance detection device also wraps Include：

Display module (12), it is connected with the processor (11), for being shown to the saliva impedance being calculated.

17. saliva impedance detection device as claimed in claim 1, it is characterised in that the saliva impedance detection device also wraps Include：

Memory module (13), for storing the saliva impedance being calculated.

18. saliva impedance detection device as claimed in claim 1, it is characterised in that the saliva impedance detection device also wraps Include：

Clock module (14), it is connected with the processor (11), for timing wake-up processor.

19. saliva impedance detection device as claimed in claim 1, it is characterised in that the saliva impedance detection device also wraps Include：

Communication module (15), it is connected with the processor (11), is communicated to connect for being established with external equipment, and by the saliva Impedance is sent to external equipment.

20. saliva impedance detection device as claimed in claim 19, it is characterised in that the communication module (15) is channel radio Believe module.

21. the saliva impedance detection device as described in claim 19 or 20, it is characterised in that the communication module (15) is indigo plant Tooth module；

The bluetooth module includes：

Bluetooth chip (151),

The XC1 pins of the Bluetooth chip (151) are connected with electric capacity C15, and XC2 pins are connected with electric capacity C14, the XC1 pins Also connected between the XC2 pins by crystal oscillator Y1；

The ANT2 pins of the Bluetooth chip (151) are connected with tie point and the second branch road, and the tie point includes series connection Electric capacity C10 and inductance L4, shunt capacitance C11 and electric capacity C12 is distinguished at the inductance L4 both ends；

Second branch road includes inductance L2, inductance L3 and the electric capacity C9 of series connection；

The ANT1 pins of the Bluetooth chip are connected between inductance L2 and inductance L3, and the VDD_PA pins of the Bluetooth chip connect It is connected between inductance L3 and electric capacity C9.

22. a kind of saliva impedance detection equipment, it is characterised in that including a kind of saliva as described in claim any one of 1-21 Impedance detection device, in addition to：Saliva impedance detection is popped one's head in and exciting signal source (17), the exciting signal source (17) pass through one Resistance is connected with saliva impedance detection probe, and pumping signal is provided for saliva impedance detection probe；

The saliva impedance detection probe, the voltage signal of the analog quantity for gathering saliva impedance both ends.

23. saliva impedance detection equipment as claimed in claim 22, it is characterised in that the exciting signal source is ac square wave Signal generator, the ac square wave signal generator include the 7th integrated operational amplifier AR7, power supply, oscillating circuit and electricity Hinder R25；

The power supply is connected to the normal phase input end of the 7th integrated operational amplifier AR7 after resistance R25 partial pressures, and described Also connected between seven integrated operational amplifier AR7 normal phase input end and the output end of the 7th integrated operational amplifier AR7 One resistance R24, the resistance R25 and the resistance R24 is to the power supply and the 7th integrated operational amplifier AR7 output ends Between voltage carry out partial pressure, the voltage obtained after partial pressure is as the 7th integrated operational amplifier AR7 normal phase input ends Reference voltage；

The normal phase input end of the 7th integrated operational amplifier AR7 is also connected and is grounded after a resistance R26；

The inverting input of the 7th integrated operational amplifier AR7 is connected with an oscillating circuit, the described 7th integrated fortune of regulation Calculate the frequency of amplifier AR7 output end output current；

Electric capacity C7, its one end are connected with the power supply, other end ground connection.

24. saliva impedance detection equipment according to claim 23, it is characterised in that the oscillating circuit includes electric capacity C6 With resistance R23；

The resistance R23 is series between inverting input and the output end of the 7th integrated operational amplifier AR7, by hysteresis The output voltage control of comparator is between VCC and 0；

The inverting input of 7th integrated operational amplifier is grounded after being also connected with the electric capacity C6.

25. saliva impedance detection equipment as claimed in claim 22, it is characterised in that the saliva impedance detection probe bag Include：Carry base portion (1), induced electricity pole piece (2), communication line (3) and interface (4)；

The carrying base portion (1), for being sticked on saliva of buccal cavity surface；

The induced electricity pole piece (2), it is embedded on the surface of the carrying base portion (1), the induced electricity pole piece (2) is used for and oral cavity Saliva contacts form physics electric loop so that the saliva of buccal cavity is equivalent to a blocked impedance in electric loop；

The communication line (3), its one end electrically connect with the induced electricity pole piece (2), and the other end is electrically connected with the interface (4) Connect, the communication line (3) is used to pass through the interface (4) to induced electricity pole piece (2) the input stimulus alternating message source.

26. saliva impedance detection equipment as claimed in claim 25, wherein, the induced electricity pole piece (2) is shaped as circle； The quantity of the induced electricity pole piece (2) is arranged to two, for encouraging the input of alternating message source；Two induced electricity pole pieces (2) it be arranged in parallel, and is generally aligned in the same plane, forms same contact plane.

27. saliva impedance detection equipment as claimed in claim 25, the surface of the carrying base portion (1) is also embedded with a ground connection Electrode slice (5), the grounding electrode piece (5) are used to connect ground wire；

Two induced electricity pole pieces (2) and the grounding electrode piece (5) arrangement triangular in shape, and be embedded in the carrying The center of the curved surfaces of base portion (1).

28. saliva impedance detection equipment as claimed in claim 25, wherein, every induced electricity pole piece (2) it is a diameter of 6mm-10mm, it is preferred that a diameter of 7mm-9mm of the every induced electricity pole piece (2)；Preferably, the every induction electrode A diameter of 8mm of piece (2).

29. saliva impedance detection equipment as claimed in claim 25, wherein, it is provided with the sensing in the carrying base portion (1) The end surface shape of one end of electrode slice (2) is circular or ellipse, and described circular or ellipse lower section is provided with stationary plane (7), the stationary plane (7) extends along described circular or ellipse lower edge curve.

30. saliva impedance detection equipment as claimed in claim 25, wherein, the carrying base portion (1), it is in strip to be also associated with Grip part (6), the receiving channel for accommodating the communication line (3) is provided with the grip part (6).