CN104997569A - Comprehensive tooth measuring instrument based on detachable tooth socket - Google Patents

Abstract

The invention discloses a comprehensive tooth measuring instrument based on a detachable tooth socket. The measuring instrument comprises a tooth biting collecting unit, a tooth looseness collecting unit, the tooth clamping socket, a data collecting card, a data processing unit, a wireless communication unit and a controller. The tooth biting collecting unit and the tooth looseness collecting unit are installed on the tooth clamping socket and are thin film three-dimensional force pressure sensors. Each sensor comprises a control unit, an X-direction capacitor unit set and a Y-direction capacitor unit set, wherein the X-direction capacitor unit set and the Y-direction capacitor unit set are connected with the control unit. According to the comprehensive tooth measuring instrument, as the tooth biting collecting unit and the tooth looseness collecting unit are matched and carry out accurate measuring and the sensors are improved and are small in thickness, influences on the detection accuracy are quite small, measurement of biting force has important reference value in diagnosing and treating tooth diseases, and the problems that in the prior art, the detection result is inaccurate, the difference is large and data are unreliable are solved.

Description

A kind of tooth general measuring instrument based on detachable facing

Technical field

The invention belongs to tooth detection field, relate to the general measuring instrument accurately measured, be specifically related to a kind of tooth general measuring instrument based on detachable facing.

Background technology

Us can be helped to have an objective understanding comparatively accurately to the damaged condition of oral cavity cacodontia by the measurement of dental articulation power and odontoseisis displacement, and have important reference value to the diagnosis of multiple periodontal disease.

The masticatory pressure that produced by the effect of muscle when gmatjpdumamics is the contact of upper lower tooth, this strength is delivered to periodontal tissue by tooth and is delivered to jawbone again and disperses.No matter be natural teeth or artificial tooth, they must play function by gmatjpdumamics.The pathological changes of tooth body, periodontal must make gmatjpdumamics reduce.After wearing artificial tooth, gmatjpdumamics is lower than natural teeth.Clinical research shows, gmatjpdumamics is one of important symbol reflecting masticatory muscles, stomatognathic system.Us can be helped to understand the function status of stomatognathic system by the size measuring gmatjpdumamics, and provide reference to the diagnosis of various diseases.The illness at each position in top collar portion all may cause the decline of gmatjpdumamics.Patient's gmatjpdumamics of disorders of temporomandibular joint has obvious decline than normal person.Serious error articulation deformity, the acute injury of hinge area also can cause the remarkable reduction of gmatjpdumamics.Because gmatjpdumamics is relevant with various diseases, the reference index therefore can recovered as masticatory function in the therapeutic process of a lot of disease.

Tooth mobility diagnostic method conventional in current domestic clinical oral is that doctor rocks tested tooth by using dental forceps, diagnoses its aeration level.The method lacks objective quantitative criteria, there is the similar and different tester of tester simultaneously and applies power difference, the problem that diagnostic result is different.

Summary of the invention

In order to overcome above the deficiencies in the prior art, the present invention proposes a kind of tooth general measuring instrument based on detachable facing, by the cooperation of dental articulation collecting unit, odontoseisis collecting unit with accurately measure, and can not improve sensor, thickness is little, very little on the impact of detection accuracy, the Diagnosis and Treat of measurement to odontopathy for gmatjpdumamics has important reference value, solve testing result in prior art inaccurate, difference is large, the insecure problem of data.

To achieve these goals, the technical scheme that the present invention takes is: a kind of tooth general measuring instrument based on detachable facing, this measuring instrument comprises dental articulation collecting unit, odontoseisis collecting unit, tooth cutting ferrule, data collecting card, data processing unit, wireless communication unit and controller, described dental articulation collecting unit, odontoseisis collecting unit is installed on tooth cutting ferrule, described data collecting card gathers dental articulation collecting unit, the data of odontoseisis collecting unit, described data processing unit delivers to controller by after the information processing of data collecting card collection, described data processing unit, wireless communication unit is connected with controller respectively, described wireless communication unit communicates with long-range receiving element, described dental articulation collecting unit, odontoseisis collecting unit all adopts thin film three-dimensional force pressure transducer.The X-direction capacitor cell group that described thin film three-dimensional force pressure transducer comprises control unit, be connected respectively with control unit and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, described capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.Described tooth cutting ferrule comprises side cover and end cover, and described side cover and the end are overlapped and removably connect, and described odontoseisis collecting unit is installed on side and puts, and described dental articulation collecting unit is installed on the end and puts.Cover of the described end comprises the end cover card for mutually removably connecting, cover card top and bottom, the end are equipped with the end cover clamping structure of card and dental articulation collecting unit, side cover comprises the side cover card for mutually removably connecting, side cover card one side is provided with the side cover clamping device of card and odontoseisis collecting unit, and one side is provided with and the card of tooth seamless link and device.Described data processing unit comprises data filtering units, data sorting unit, Data Fusion unit and Database Unit, described data filtering units is used for the wrong data that filtered sensor gathers, described data sorting unit is classified to the data after filtration, Data Fusion unit carries out fusion treatment according to the data of data sorting unit and exports two-dimensional data table, data base detects data and normal data for storing, and described normal data is normal tooth data.

In said apparatus, described capacitor cell module comprises by two or more width a ₀length b ₀strip capacitor cell composition the first strip capacitor cell group and two or more width ka ₀length b ₀strip capacitor cell composition the second strip capacitor cell group.The drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein, b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell, described poor position δ _left=δ _right, and wherein d ₀for strip capacitor cell dielectric thickness, G is the modulus of rigidity of elastic fluid, τ _maxfor maximum stress value.The lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode spacing a between adjacent two strip capacitor cells _δ, described parallel-plate area S=M (a ₀+ 2 _{a δ}+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.The strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is connected to control unit by parallel or independent mode.The width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.Described first strip capacitor cell group and be respectively equipped with intermediate translator between the second strip capacitor cell group and control unit, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.

Beneficial effect of the present invention is: in order to improve the degree of accuracy of tooth general measuring instrument, dental articulation collecting unit is equipped with in the present invention, odontoseisis collecting unit, and for installing the tooth cutting ferrule of collecting unit, card and every tooth one_to_one corresponding are overlapped in each side cover card and the end, the size of side cover card and end cover card carries out being arranged to one group according to the stock size of tooth, card and end cover card one_to_one corresponding are overlapped in the size of thin film three-dimensional force pressure transducer and side, different side cover cards and end cover card can be set for different teeth like this, for the side cover card and the end cover card that need the tooth measured can install and measure separately tooth, avoid impact each other, also prevent the impact transmitting data simultaneously.In order to improve the sensitivity of thin film three-dimensional force pressure transducer, the reliability and stability of conversion accuracy and touch sensing system, have devised with pcb board the dielectric layer be parallel-plate electrode and PDMS being base material, planar dimension is 10 × 10mm ²combined electric capacity Sensitive Apparatus.The present invention, by the basis of capacitance measurement three-dimensional force, effectively uses platen area, and is effectively solved between three-dimensional force by the method such as differential and be coupled, thus makes normal direction and tangential conversion all reach higher linear, precision and sensitivity.

Accompanying drawing explanation

Below the content expressed by this Figure of description and the labelling in figure are briefly described:

Fig. 1 is the work structuring block diagram of the specific embodiment of the present invention.

Fig. 2 is strip capacitor cell and the coordinate system thereof of the specific embodiment of the present invention.

Fig. 3 is the strip capacitor cell schematic diagram of the specific embodiment of the present invention.

Fig. 4 is the strip capacitor cell dextrad skew schematic diagram of the specific embodiment of the present invention.

Fig. 5 is the strip capacitor cell left-hand skew schematic diagram of the specific embodiment of the present invention.

Fig. 6 is the width of the specific embodiment of the present invention is a ₀and ka ₀electric capacity to stressed deflection graph.

Fig. 7 is the parallel-plate three-dimensional force pressure sensor structure figure of the specific embodiment of the present invention.

Fig. 8 is the signal schematic representation that the cell capacitance of the specific embodiment of the present invention is right.

Fig. 9 is the plane-parallel capacitor cross-section structure of the specific embodiment of the present invention.

Wherein, 1, upper PCB substrate, 2, lower PCB substrate, 3, drive electrode, 4, induction electrode, 5, elastic fluid.

Detailed description of the invention

Contrast accompanying drawing below, by the description to embodiment, the specific embodiment of the present invention is as the effect of the mutual alignment between the shape of involved each component, structure, each several part and annexation, each several part and operation principle, manufacturing process and operation using method etc., be described in further detail, have more complete, accurate and deep understanding to help those skilled in the art to inventive concept of the present invention, technical scheme.

A kind of tooth general measuring instrument based on detachable facing, its structured flowchart as shown in Figure 1, this measuring instrument comprises dental articulation collecting unit, odontoseisis collecting unit, tooth cutting ferrule, data collecting card, data processing unit, wireless communication unit and controller, described dental articulation collecting unit, odontoseisis collecting unit is installed on tooth cutting ferrule, described data collecting card gathers dental articulation collecting unit, the data of odontoseisis collecting unit, described data processing unit delivers to controller by after the information processing of data collecting card collection, described data processing unit, wireless communication unit is connected with controller respectively, described wireless communication unit communicates with long-range receiving element, described dental articulation collecting unit, odontoseisis collecting unit all adopts thin film three-dimensional force pressure transducer, long-range receiving element can be hands machine, the signal receivers such as server.

Described tooth cutting ferrule comprises side cover and end cover, and described side cover and the end are overlapped and removably connect, and described odontoseisis collecting unit is installed on side and puts, and described dental articulation collecting unit is installed on the end and puts.Cover of the described end comprises the end cover card for mutually removably connecting, cover card top and bottom, the end are equipped with the end cover clamping structure of card and dental articulation collecting unit, side cover comprises the side cover card for mutually removably connecting, side cover card one side is provided with the side cover clamping device of card and odontoseisis collecting unit, and one side is provided with and the card of tooth seamless link and device.

Side cover and end cover are formed respectively by side cover card and end cover card, card and every tooth one_to_one corresponding are overlapped in each side cover card and the end, the size of side cover card and end cover card carries out being arranged to one group according to the stock size of tooth, card and end cover card one_to_one corresponding are overlapped in the size of thin film three-dimensional force pressure transducer and side, different side cover cards and end cover card can be set for different teeth like this, for the side cover card and the end cover card that need the tooth measured can install and measure separately tooth, avoid impact each other, also prevent the impact transmitting data simultaneously.

During installation, for the tooth needing to measure, select side cover card and the end cover card of suitable dimension, then select suitable thin film three-dimensional force pressure transducer in side cover card and end cover card according to the side of suitable dimension cover card and end cover card and, side is overlapped card and the end cover card connect to form respectively cutting ferrule and the end cover, after cutting ferrule being displaced into the tooth position overlap needing to measure, by the side cover card of card and device, side cover being fixed on tooth, afterwards end cover being installed on side and putting.End cover can arrange one side according to actual needs and place dental articulation collecting unit, or dental articulation collecting unit is all placed on two sides, effectively can reduce the thickness of tooth like this, improves certainty of measurement.

Described data processing unit comprises data filtering units, data sorting unit, Data Fusion unit and Database Unit, described data filtering units is used for the wrong data that filtered sensor gathers, described data sorting unit is classified to the data after filtration, Data Fusion unit carries out fusion treatment according to the data of data sorting unit and exports two-dimensional data table, data base detects data and normal data for storing, and described normal data is every data of normal tooth.

The X-direction capacitor cell group that thin film three-dimensional force pressure transducer comprises control unit, be connected respectively with control unit and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, described capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.Described capacitor cell module comprises by two or more width a ₀length b ₀first strip capacitor cell group of strip capacitor cell composition and two or more width ka ₀length b ₀second strip capacitor cell group of strip capacitor cell composition.The drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein, b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell.Described poor position δ _left=δ _right, and wherein d ₀for dielectric thickness, G is the modulus of rigidity of elastic fluid, τ _maxfor maximum stress value.The lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode spacing a between adjacent two strip capacitor cells _δ.Described parallel-plate area S=M (a ₀+ 2 _{a δ}+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.The strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is by parallel connection or be independently connected to control unit.The width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.Described first strip capacitor cell group and be provided with intermediate translator between the second strip capacitor cell group and control unit, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.

1, the transfer characteristic of strip capacitor cell

(1) pumping signal and coordinate system

Strip capacitor cell is placed in the rectangular coordinate system shown in Fig. 2, pole plate plane length b ₀, width a ₀, dielectric thickness d ₀.Three-dimensional simulation puts on the outer surface of capacitor plate, and the contact active force of generation has Fx, Fy and Fz tri-durection components, and the action direction of Fx and Fy is along X-axis and Y-axis, and the action direction of Fz along OZ axle namely direction, normal direction and tangential stress are a kind of stress tensor, can output capacitance respond between the lead-in wire of electrode; Normal stress σ _n=Fn/A, wherein A=a ₀b ₀for pole plate normal direction stress surface, Fn=Fz is normal component; Both side surface produces paired tangential stress τ _x=Fx/A, τ _y=Fy/A.

According to the Hooke's law in Elasticity, σ _nand τ _x, τ _yelastomer all will be made to produce corresponding distortion.Wherein,

${\mathrm{\σ}}_n=E\·{\mathrm{\ϵ}}_n=E\·{\mathrm{\δ}}_n/d_0=\frac{F_n}{A}---\left(1\right)$

$\±{\mathrm{\τ}}_x=\±{\mathrm{\γ}}_x\·G=\±G\·{\mathrm{\δ}}_x/d_0=\±\frac{F_x}{A}---\left(2\right)$

$\±{\mathrm{\τ}}_y=\±{\mathrm{\γ}}_y\·G=\±G\·{\mathrm{\δ}}_y/d_0=\±\frac{F_y}{A}---\left(3\right)$

In formula, E is the Young's modulus (unit: GN/m of elastic fluid ²), G is the modulus of rigidity (unit: GN/m of elastic fluid ²), δ n is the Normal Displacement (unit: μm) of elastic fluid, and δ x and δ y is the relative dislocation (unit: μm) of the upper and lower two-plate of capacitor, and its sign is pointed to by coordinate axes and determined.

(2) capacitance equation and input-output characteristic thereof

The initial capacitance of rectangular parallel plate capacitor is:

$C_0=\frac{{\mathrm{\ϵ}}_0.{\mathrm{\ϵ}}_r\·a_0\·b_0}{d_0}---\left(4\right)$

In formula, ε ₀vacuum medium electric constant is 8.85PF/m, ε _r=2.5 is dielectric relative dielectric constant.D ₀by σ _nexcitation produce relative deformation ε _n=δ _n/ d ₀=σ _n/ E, substitutes into (4) and obtains input-output characteristic

$C_n={\mathrm{\ϵ}}_0.{\mathrm{\ϵ}}_r\frac{a_0\·b_0}{d_0(1-{\mathrm{\ϵ}}_n)}={\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\frac{a_0\·b_0}{d_0(1-\frac{F_n}{AE})}---\left(5\right)$

(3) linearity under normal stress effect and sensitivity

A, the normal direction linearity

F in (5) formula _nin the denominator, therefore C _n=f (F _n) relation be nonlinear, because of conversion range in maximum σ _nmaxcompared with dielectric resilient constant E, ε _na very little amount, i.e. ε in denominator _n<<1, (5) are omitted the higher-order shear deformation of more than quadratic power by series expansion, and (5) formula can be reduced to:

$C_n=C_0(1+\mathrm{\&epsiv;})=C_0(1+\frac{F_n}{A\&CenterDot;E})---\left(6\right)$

Visible at C _nwith F _ntransfer characteristic in the maximum relative error of the normal direction linearity close to zero.

B, sensitivity

By the definition of normal direction sensitivity

Can linear sensitivity be obtained by (6) formula,

S _n1＝C ₀/AE＝ε ₀ε _r/d ₀E (7)

By (5) formula then

$S_{n2}=\frac{{\mathrm{dC}}_n}{{\mathrm{dF}}_n}=C_0\&CenterDot;\frac{1}{1-2\mathrm{\&epsiv;}}=C_0\&CenterDot;\frac{1}{1-2\frac{F_n}{A\&CenterDot;E}}---\left(8\right)$

S _n2with F _nand become, F _nlarger, S _n2larger, in mild nonlinear in whole transfer characteristic.

(4) tangential stress τ _xand τ _ycapacitance variations under excitation

Tangential stress τ _xand τ _ydo not change the physical dimension parameter b of pole plate ₀and a ₀, to dielectric thickness d ₀also do not have an impact.But τ _xand τ _ychange the space structure of strip capacitor cell, between the upper bottom crown faced by forward, there occurs dislocation skew.Now for OX direction, pole plate is at τ _xdislocation skew δ under effect _x.

Work as τ in figure 3 _xwhen being zero, a _{on 0}=a _{0 time}just right, effective cross-section A between substrate _τ=a ₀b ₀; In the diagram, at τ _xunder the effect of dextrad, top crown creates dislocation skew δ to the right relative to bottom crown _x, thus make the effective area A between bottom crown when calculating electric capacity _τ=(a ₀-δ _x) b ₀; In Fig. 5, work as τ _xduring for left-hand, dislocation skew δ _xthen left, A _τ=(a ₀-δ _x) b ₀, τ _xwhen left-hand and dextrad, the reduction of effective area is identical, and consequent electric capacity is:

$C_{\mathrm{\&tau;}x}=\frac{{\mathrm{\&epsiv;}}_0.{\mathrm{\&epsiv;}}_r\&CenterDot;(a_0-{\mathrm{\&delta;}}_x)\&CenterDot;b_0}{d_0}---\left(9\right)$

According to shearing Hooke's law

τ _x＝γ _x·G＝G·δ _x/d ₀(10)

(10) are substituted into (9) can obtain

$C_{\mathrm{\&tau;}x}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;{\mathrm{\&delta;}}_x\&CenterDot;b_0}{d_0}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(11\right)$

(11) formula is the input-output characteristics under shearing stress, C _τwith τ _xlinear.

And its sensitivity

$S_{\mathrm{\&tau;}x}=\frac{{\mathrm{dC}}_{\mathrm{\&tau;}x}}{{\mathrm{dF}}_x}=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}---\left(12\right)$

The similar analysis in formula (9)-(12) is suitable for and τ equally _ywith C _{τ y}characteristic and technical specification, the only long limit b of strip capacitor cell in formula ₀oX direction of principal axis should be arranged at, and its minor face a ₀then in OY direction.

2, contact parallel plate capacitor design

(1) planar design of parallel plate capacitor

The original index normal direction Max.contact stress σ of setting _nmaxfor 200Kpa, if the stressed A of normal direction is square 10 × 10mm ², then maximum normal force F _zmaxfor σ _nmaxa=20N.Tangential Max.contact stress τ _maxfor 70Kp, the distribution of force face of tangential stress is 10 × 10mm ², then maximum tangential force component F _xmax=F _ymax=τ _maxa=7N.

Strip capacitor cell constructive variations shown in Fig. 4 and Fig. 5, only illustrates that electric capacity exports and tangential stress ± τ _xthe relation of input, capacitance increase is all negative, and therefore this initial capacitance structure is not suitable for as right ± τ _xobtain the response increasing and decreasing electric capacity.The present invention adjusts the initiating structure of bottom crown on strip capacitor cell for this reason, and width is a ₀and ka ₀strip capacitor cell form a pair capacitor cell to (C _lwith C _r), specifically as shown in Figure 6.

In Fig. 6, capacitor cell C _land C _relectrode size b ₀, d ₀all identical, width one is a ₀, one is ka ₀, wherein k is constant, is preferably greater than the integer of 1.Work as τ _xwhen=0, C _l=C ₀, C _r=kC ₀, on this basis as at F _xδ is produced under excitation _xmistake skew, offset effect as shown in fig. 4 or 5 will be formed.

$C_L=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;(a_0-{\mathrm{\&delta;}}_x)}{d_0}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(13\right)$

$C_R=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;({\mathrm{Ka}}_0-{\mathrm{\&delta;}}_x)}{d_0}={\mathrm{kC}}_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}={\mathrm{kC}}_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(14\right)$

C _land C _rcapacitor cell is at same τ _xδ will be produced _xwith Δ C _τresponse.

Thus, formula (11) can be revised as

$C_{\mathrm{\&tau;}x}=C_{\mathrm{\&tau;}0}-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}{F}_x$

In formula, for initial capacitance when shearing stress is zero, above formula is shearing stress input-output characteristic, C _{τ x}with F _xlinear relationship, and its sensitivity

Electrode plane see Fig. 7 is arranged, at a 10 × 10mm ²substrate center do cross separate, form four quadrants, upper right first quartile I, upper left second quadrant II, lower-left third quadrant III, bottom right fourth quadrant IV, wherein I, III quadrant is to τ _xmake the capacitor cell combination of response, and II, IV quadrant is to τ _ymake the capacitor cell combination of response.Object-line is 10 × 10mm ²pcb board four edge lines, hachure part represents the outer mode cross section of wax-loss casting process.Using the position of induction electrode in lower floor's PCB substrate as reference, then the layout of drive electrode in the PCB substrate of upper strata should with PCB substrate edge line for benchmark.In figure, four dashed rectangle are the benchmark of induction electrode on bottom crown, put they and geometry datum line differential apart from being δ ₀(0.1mm).

Capacitor cell module adopts comb structure, and capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.By formula (12) a ₀less, the sensitivity of tangential stress response is larger, therefore single capacitor cell is strip.If every root strip capacitor cell is wide is a ₀, the groove width between two strip electric capacity is a _δ, then the pitch of every root strip capacitor cell is ka ₀+ a ₀+ 2a _δ.In order to make full use of the plane space of square substrate, M (ka ₀+ a ₀+ 2a _δ) b ₀/ 2 ≈ 1 square substrate areas, M is strip electric capacity quantity, then have M (ka ₀+ a ₀+ 2a _δ)=20mm, in formula, groove width a _δunsuitable excessive, otherwise be unfavorable for using the effective plane space on substrate, also unsuitable too small, the constraint of wax-loss casting process is subject to.For making normal direction sensitivity S _nwith tangential sensitivity S _τequal, by formula (7) and (12), make a ₀g=d ₀e, works as d ₀when=0.1mm, k=1.5, thus M can be obtained.

In order to realize τ _xand τ _ymutually do not have an impact between tangential response, the drive electrode length two ends reserved difference position δ of strip capacitor cell ₀, therefore b _{0 drives}=b _{0 end}+ 2 δ ₀, wherein at b _{0 drives}two ends length reserved difference potential theory should ensure its value of calculation is ${10}^{-5}\&times;\frac{70\&times;{10}^3}{2.4\&times;{10}^6}=2.9\&times;{10}^{-8}m={10}^{-2}um<<1um,$ Therefore should b be ensured in technique _{0 drives}-b _{0 end}>=0.01mm.Like this when computing method exports response to electric capacity, ensure τ _xand τ _yany impact is not produced on the response of normal direction electric capacity.

In order to realize τ _xand τ _ydo not produce any impact to the response of normal direction electric capacity, width is a ₀and ka ₀strip capacitor cell form a pair capacitor cell to (C _lwith C _r) carry out publicity reckoning elimination impact each other.Ensure τ _xproduce τ at I, III quadrant capacitor cell _xelectric capacity response, then produce τ at II, IV quadrant capacitor cell _yelectric capacity response, to ensure that capacitor cell in four quadrants is at τ _xand τ _ytwo groups of differential capacitors pair can be produced under tangential excitation.

(2) calculating of normal stress and tangential force

If width is a in Fig. 6 ₀strip capacitor cell be subject to tangential force τ _x, produce a tangential displacement d _xafter output capacitance value be C ₁, width is ka ₀strip capacitor cell be subject to tangential force τ _x, produce a tangential displacement d _xafter output capacitance value be C ₂, then have:

$C_1=\frac{\mathrm{\&epsiv;}(a_0-d_x)b_0}{d_n}=\frac{{\mathrm{\&epsiv;a}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;b}}_0{d}_x}{d_n}---\left(15\right)$

$C_2=\frac{\mathrm{\&epsiv;}({\mathrm{ka}}_0-d_x)b_0}{d_n}=\frac{{\mathrm{\&epsiv;ka}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;b}}_0{d}_x}{d_n}---\left(16\right)$

Obtained by (15)-(16):

$C_1-C_2=\frac{{\mathrm{\&epsiv;a}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;ka}}_0{b}_0}{d_n}$ Calculate:

$d_n-\frac{{\mathrm{\&epsiv;a}}_0{b}_0(1-k)}{C_1-C_2}---\left(17\right)$

Obtained by (15) * k-(16):

${\mathrm{kC}}_1-C_2=\frac{{\mathrm{\&epsiv;d}}_x{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;kd}}_x{b}_0}{d_n}=\frac{{\mathrm{\&epsiv;d}}_x{b}_0(1-k)}{d_n},$ (17) are substituted into above formula, can obtain:

$d_x=\frac{a_0({\mathrm{kC}}_1-C_2)}{C_1-C_2}---\left(18\right)$

According to $d_n=d_0-\mathrm{\&Delta;}d=d_0(1-\frac{F_n}{E\&CenterDot;S_0})$

Known: $F_n=\frac{(d_n-d_0)E\&CenterDot;S_0}{d_0}$

By $\frac{d_x}{d_0}=\mathrm{\&gamma;}=\frac{\mathrm{\&tau;}}{G}=\frac{F_{\mathrm{\&tau;}}}{G\&CenterDot;S_0},$ So $F_{\mathrm{\&tau;}x}=\frac{{\mathrm{GS}}_0{d}_x}{d_0}.$

In above formula, no matter be normal direction excitation F _nor tangentially encourage F _yall not to O _τhave an impact.Namely automatically σ is eliminated _nand τ _yto τ _xthe coupling of total output or interference because every in signal packet containing in the computing of subtracting each other, equivalent and the capacitance variations with symbol are eliminated all automatically.And F _yand F _xto σ _ninterference by upper electrode at b ₀direction increases geometrical length 2 δ ₀eliminate.In like manner F can be obtained _{τ y}.

(4) main material selection and characterisitic parameter thereof

The section of structure of comb teeth-shaped plane-parallel capacitor is similar to the sandwich structure shown in Fig. 9, and in Fig. 9,1 is upper PCB substrate, and 2 is lower PCB substrate, and 3 is drive electrode, and 4 is induction electrode, and 5 is elastic fluid.Pole plate is apart from d ₀=0.1mm, upper and lower base plate inner space, except copper foil electrode, is PDMS (polydimethylsiloxane) the superlastic dielectric with lost wax process filling.Its machinery and physical characteristic parameter are Young's modulus E=6.2MPa, and its shear modulus is G=4.1MPa, relative DIELECTRIC CONSTANT ε during dielectric polorization _γ=2.5.Because E and G of medium is much smaller than the elastic modulus E of copper _copper=103GPa, therefore the distortion of capacitor internal medium under stress state is much larger than the distortion of pole plate.

(5) contact conductor design

Be that drive electrode or induction electrode all need to have lead-out wire, consider that each drive electrode is all ground connection in signal level, therefore four groups of drive electrodes only need share same lead-out wire.The induction electrode of four the first strip capacitor cell groups and the second strip capacitor cell group then needs with respective independently lead-out wire, and draw from the side of planar package so whole capacitance component has at least 5 pins, four induction electrodes refer to that X-direction width is a ₀induction electrode and width be ka ₀induction electrode, and Y-direction width is a ₀induction electrode and width be ka ₀induction electrode so that whole assembly top and bottom outer surface can contact with measuring object easily.The present invention, under the support of new material and new technology, completes the design of a kind of novel three-dimensional power sensitization capacitance combination, at 10 × 10mm ²stress surface on, be no matter normal direction or tangential, all can transmit stress more uniformly to medium.In literary composition, four cell capacitance are two to combination distribution.In the contact of non-coplanar force and sensor surface, external force only has 1, and electric capacity response but has 4, and whole battery lead plate, all to asking Fn to contribute, simultaneously by two pairs of capacitor combinations composition systems, can obtain F again _xand F _yinformation, thus complete description three-dimensional force.

Above by reference to the accompanying drawings to invention has been exemplary description; obvious specific implementation of the present invention is not subject to the restrictions described above; as long as have employed the improvement of the various unsubstantialities that method of the present invention is conceived and technical scheme is carried out; or design of the present invention and technical scheme directly applied to other occasion, all within protection scope of the present invention without to improve.The protection domain that protection scope of the present invention should limit with claims is as the criterion.

Claims (10)

1. the tooth general measuring instrument based on detachable facing, it is characterized in that, this measuring instrument comprises dental articulation collecting unit, odontoseisis collecting unit, tooth cutting ferrule, data collecting card, data processing unit, wireless communication unit and controller, described dental articulation collecting unit, odontoseisis collecting unit is installed on tooth cutting ferrule, described data collecting card gathers dental articulation collecting unit, the data of odontoseisis collecting unit, described data processing unit delivers to controller by after the information processing of data collecting card collection, described data processing unit, wireless communication unit is connected with controller respectively, described wireless communication unit communicates with long-range receiving element, described dental articulation collecting unit, odontoseisis collecting unit all adopts thin film three-dimensional force pressure transducer, described thin film three-dimensional force pressure transducer comprises control unit, the X-direction capacitor cell group be connected respectively with control unit and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, described capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.

2. tooth general measuring instrument according to claim 1, it is characterized in that, described tooth cutting ferrule comprises side cover and end cover, and described side cover and end cover removably connect, described odontoseisis collecting unit is installed on side and puts, and described dental articulation collecting unit is installed on the end and puts.

3. tooth general measuring instrument according to claim 2, it is characterized in that, cover of the described end comprises the end cover card for mutually removably connecting, cover card top and bottom, the end are equipped with the end cover clamping structure of card and dental articulation collecting unit, side cover comprises the side cover card for mutually removably connecting, side cover card one side is provided with the side cover clamping device of card and odontoseisis collecting unit, and one side is provided with and the card of tooth seamless link and device.

4. tooth general measuring instrument according to claim 1, it is characterized in that, described data processing unit comprises data filtering units, data sorting unit, Data Fusion unit and Database Unit, described data filtering units is used for the wrong data that filtered sensor gathers, described data sorting unit is classified to the data after filtration, Data Fusion unit carries out fusion treatment according to the data of data sorting unit and exports two-dimensional data table, Database Unit detects data and normal data for storing, and described normal data is normal tooth data.

5. tooth general measuring instrument according to claim 1, is characterized in that, described capacitor cell module comprises by two or more width a ₀length b ₀strip capacitor cell composition the first strip capacitor cell group and two or more width ka ₀length b ₀strip capacitor cell composition the second strip capacitor cell group.

6. tooth general measuring instrument according to claim 1, is characterized in that, the drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein, b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell, described poor position δ _left=δ _right, and wherein d ₀for strip capacitor cell dielectric thickness, G is the modulus of rigidity of elastic fluid, τ _maxfor maximum stress value.

7. tooth general measuring instrument according to claim 1, is characterized in that, the lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode spacing a between adjacent two strip capacitor cells _δ, described parallel-plate area S=M (a ₀+ 2a _δ+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.

8. tooth general measuring instrument according to claim 5, is characterized in that, the strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is connected to control unit by parallel or independent mode.

9. tooth general measuring instrument according to claim 5, is characterized in that, the width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.

10. tooth general measuring instrument according to claim 5, it is characterized in that, described first strip capacitor cell group and be respectively equipped with intermediate translator between the second strip capacitor cell group and control unit, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.