CN204798051U - Tooth general measuring instrument based on can dismantle facing - Google Patents

Abstract

The utility model discloses a tooth general measuring instrument based on can dismantle facing, this measuring apparatu include the not hard up acquisition unit of tooth interlock acquisition unit, tooth, tooth cutting ferrule, data collection card, data processing unit, radio communication unit and controller, the not hard up acquisition unit of tooth interlock acquisition unit, tooth installs on the tooth cutting ferrule, and tooth interlock acquisition unit, the not hard up acquisition unit of tooth all adopt the three -dimensional power pressure sensor of film, X direction electric capacity unique tuple and Y direction electric capacity unique tuple that the sensor includes the control unit, is connected respectively with the control unit. The utility model discloses a tooth interlock acquisition unit, the not hard up acquisition unit's of tooth cooperation and precision measurement to can not improve the sensor, thickness is little, and is very little to the influence that detects the accuracy, has important reference value to the diagnosis of odontopathy with the treatment to the measurement of snap -in force, solved prior art in the testing result inaccurate, widely different, the insecure problem of data.

Description

Tooth comprehensive measuring instrument based on detachable tooth socket

Technical Field

The utility model belongs to tooth detection area relates to accurate measurement's comprehensive measuring apparatu, concretely relates to tooth comprehensive measuring apparatu based on can dismantle facing.

Background

The measurement of the tooth occlusal force and the tooth loose displacement can help people to accurately and objectively know the damage degree of the odontopathy, and has important reference value for diagnosing various periodontal diseases.

The biting force is a masticatory pressure generated by the action of muscles when upper and lower teeth are in contact, and such force is transmitted from the teeth to the periodontal tissues and then to the jaw bone to be dispersed. Whether they are natural teeth or dentures, they must function by occlusal force. The pathological changes of tooth and periodontal inevitably reduce the occlusal force. After wearing the denture, the occlusal force is lower than that of the natural teeth. Clinical studies have shown that occlusal force is one of the important markers reflecting the masticatory muscle, oromandibular system. The measurement of the size of the occlusal force can help people to know the functional condition of the oromandibular system and provide reference for the diagnosis of various diseases. The lesions in various parts of the collar portion may cause a decrease in the occlusal force. The occlusion force of patients with temporomandibular joint disorder is obviously reduced compared with that of normal people. Severe malocclusion deformity, acute injury to the joint area can also result in a significant reduction in occlusal force. Since the biting force is related to various diseases, it can be used as a reference index for recovery of chewing function in the course of treatment of many diseases.

At present, a commonly used method for diagnosing the odontoseisis in oral clinic in China is that a doctor shakes a tested tooth by using dental forceps to diagnose the loosening degree of the tested tooth. The method lacks objective quantitative standards, and has the problems of different testers or different application forces of the same tester and different diagnosis results.

Disclosure of Invention

In order to overcome the not enough of above prior art, the utility model provides a tooth comprehensive measuring apparatu based on can dismantle facing, through tooth interlock acquisition unit, the not hard up cooperation and the accurate measurement of acquisition unit of tooth to can not improve the sensor, thickness is little, and is very little to the influence that detects the accuracy, has important reference value to the diagnosis and the treatment of odontopathy to the measurement of interlock force, has solved among the prior art that the testing result is inaccurate, and the difference is big, the unreliable problem of data.

In order to realize the purpose, the utility model discloses the technical scheme who takes does: the utility model provides a tooth comprehensive measurement appearance based on can dismantle facing, this measuring apparatu include tooth interlock acquisition unit, tooth not hard up acquisition unit, tooth cutting ferrule, data acquisition card, data processing unit, wireless communication unit and controller, tooth interlock acquisition unit, tooth not hard up acquisition unit are installed on the tooth cutting ferrule, data acquisition card gathers tooth interlock acquisition unit, the not hard up data of acquisition unit of tooth, data processing unit sends the controller to after with the information processing of data acquisition card collection, data processing unit, wireless communication unit are connected with the controller respectively, wireless communication unit communicates with remote receiving unit, tooth interlock acquisition unit, tooth not hard up acquisition unit all adopt three-dimensional force pressure sensor of film. The film three-dimensional pressure sensor comprises a control unit, an X-direction capacitor unit group and a Y-direction capacitor unit group, wherein the X-direction capacitor unit group and the Y-direction capacitor unit group are respectively connected with the control unit, the X-direction capacitor unit group and the Y-direction capacitor unit group respectively comprise capacitor unit modules, each capacitor unit module adopts a comb-shaped structure consisting of more than two strip-shaped capacitor units, and each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate. The tooth cutting ferrule comprises a side sleeve and a bottom sleeve, the side sleeve and the bottom sleeve are detachably connected, the tooth looseness acquisition unit is installed on the side sleeve, and the tooth occlusion acquisition unit is installed on the bottom sleeve. The end cover is including the end cover card that can dismantle the connection each other, and the end cover clamping structure that all is equipped with card and tooth interlock acquisition unit about the end cover card, and the side cover is including the side cover card that can dismantle the connection each other, and the side cover card simultaneously is equipped with the side cover clamping device of card and the not hard up acquisition unit of tooth, the one side be equipped with tooth seamless connection's card and device. The data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, wherein the data filtering unit is used for filtering error data collected by the sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit to output a two-dimensional data table, the database is used for storing detection data and standard data, and the standard data are normal tooth data.

In the above device, the capacitor unit module comprises at least two widths a₀Length b₀Strip shape ofA first strip-shaped capacitor unit group consisting of capacitor units and more than two widths ka₀Length b₀And the second strip-shaped capacitor unit group is formed by the strip-shaped capacitor units. The width of the driving electrode and the width of the induction electrode of each strip-shaped capacitor unit are the same, the length of the driving electrode is greater than that of the induction electrode, and left difference positions delta are reserved at two ends of the length of the driving electrode respectively_{Left side of}And the right difference position delta_{Right side}，b_{0 drive}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein, delta_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitor unit is delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the dielectric of the strip-shaped capacitor unit, G is the shear modulus of the elastic dielectric, tau_maxThe maximum stress value. The comb-shaped structure comprises more than 20 strip-shaped capacitor units and leads connected with the strip-shaped capacitor units in a one-to-one correspondence manner, and an electrode distance a is arranged between every two adjacent strip-shaped capacitor units_δThe parallel plate area S ═ M (a)₀+2a_δ+ka₀)b₀A/2, wherein M is the number of strip-shaped capacitor units, b₀Is the length of the strip-shaped capacitor unit, a₀The width of the strip-shaped capacitor unit. The strip-shaped capacitor unit leads of the first strip-shaped capacitor unit group and the second strip-shaped capacitor unit group are connected to the control unit in a parallel connection or independent mode. Width of the strip-shaped capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium. Intermediate converters are respectively arranged between the first strip-shaped capacitor unit group and the control unit, between the second strip-shaped capacitor unit group and the control unit, and are used for setting transmission coefficients of voltage to capacitance or frequency to capacitance.

The utility model has the advantages that in order to improve the accuracy of the tooth comprehensive measuring instrument, the utility model discloses aThe tooth interlock acquisition unit has been equipped with in the type, the not hard up acquisition unit of tooth, and be used for installing the tooth cutting ferrule of acquisition unit, every side cover card and end cover card and every tooth one-to-one, the size of side cover card and end cover card sets into a set ofly according to the conventional size of tooth, the size and the side cover card and the end cover card one-to-one of film three-dimensional force pressure sensor, can set up different side cover card and end cover card to different tooth like this, can install the side cover card and the end cover card of measuring the tooth alone to the tooth that needs the measurement, avoid influence each other, the influence of transmission data also prevents simultaneously. In order to improve the sensitivity, the conversion precision and the reliability and the stability of a touch sensing system of the film three-dimensional force pressure sensor, a dielectric layer which takes a PCB (printed Circuit Board) as a parallel plate electrode and PDMS (polydimethylsiloxane) as a base material is designed, and the plane size is 10 multiplied by 10mm²The combined capacitance sensitive device of (1). The utility model discloses on the basis through electric capacity measurement three-dimensional power, effectively use dull and stereotyped area to effectively solve the coupling between three-dimensional power through methods such as differential, thereby make normal direction and tangential conversion all reach higher linearity, precision and sensitivity.

Drawings

The contents of the drawings and the reference numerals in the drawings are briefly described as follows:

fig. 1 is a block diagram of an operation structure of an embodiment of the present invention.

Fig. 2 shows a strip-shaped capacitor unit and its coordinate system according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a strip capacitor unit according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of rightward shift of a strip-shaped capacitor unit according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of left-shift of a strip-shaped capacitor unit according to an embodiment of the present invention.

FIG. 6 shows an embodiment of the present invention having a width of a₀And ka₀Capacitance versus force deflection plot of (a).

Fig. 7 is a structural diagram of a parallel plate three-dimensional force pressure sensor according to an embodiment of the present invention.

Fig. 8 is a signal diagram of a pair of cell capacitors according to an embodiment of the present invention.

Fig. 9 is a cross-sectional structure of a parallel plate capacitor according to an embodiment of the present invention.

The PCB comprises an upper PCB substrate 1, a lower PCB substrate 2, a driving electrode 3, a sensing electrode 4, an elastic medium 5 and a plurality of electrodes.

Detailed Description

The following description of the embodiments with reference to the drawings is intended to illustrate the present invention in further detail, such as the shapes and structures of the components, the mutual positions and connections between the components, the functions and working principles of the components, the manufacturing process, and the operation and use methods, etc., so as to help those skilled in the art understand the present invention more completely, accurately and deeply.

A tooth comprehensive measuring instrument based on a detachable tooth socket is shown in a structural block diagram in figure 1 and comprises a tooth occlusion collecting unit, a tooth looseness collecting unit, a tooth socket, a data collecting card, a data processing unit, a wireless communication unit and a controller, wherein the tooth occlusion collecting unit and the tooth looseness collecting unit are installed on the tooth socket, the data collecting card collects data of the tooth occlusion collecting unit and the tooth looseness collecting unit, the data processing unit processes information collected by the data collecting card and then sends the information to the controller, the data processing unit and the wireless communication unit are respectively connected with the controller, the wireless communication unit is communicated with a remote receiving unit, the tooth occlusion collecting unit and the tooth looseness collecting unit all adopt film three-dimensional force pressure sensors, and the remote receiving unit can be a mobile phone, a mobile phone and a mobile phone A server, etc.

The tooth cutting ferrule comprises a side sleeve and a bottom sleeve, the side sleeve and the bottom sleeve are detachably connected, the tooth looseness acquisition unit is installed on the side sleeve, and the tooth occlusion acquisition unit is installed on the bottom sleeve. The end cover is including the end cover card that can dismantle the connection each other, and the end cover clamping structure that all is equipped with card and tooth interlock acquisition unit about the end cover card, and the side cover is including the side cover card that can dismantle the connection each other, and the side cover card simultaneously is equipped with the side cover clamping device of card and the not hard up acquisition unit of tooth, the one side be equipped with tooth seamless connection's card and device.

Side cover and end cover are formed through side cover card and end cover card respectively, every side cover card and end cover card and every tooth one-to-one, the size of side cover card and end cover card sets into a set ofly according to the conventional size of tooth, the size of the three-dimensional force pressure sensor of film and side cover card and end cover card one-to-one, can set up different side cover card and end cover card to different teeth like this, to the side cover card and the end cover card that need measured tooth of installation measurement tooth alone, avoid influence each other, the influence of transmission data also prevents simultaneously.

During the installation, to the tooth that needs to be measured, select suitable size's side cover card and end cover card, then according to suitable size's side cover card and end cover card select suitable three-dimensional force pressure sensor of film in side cover card and end cover card with, connect respectively side cover card and end cover card and form cutting ferrule and end cover, move the cutting ferrule in the tooth position that needs to be measured and superpose the back, will incline the cover through the card and the device of side cover card and be fixed in on the tooth, later install the end cover on the side cover. The bottom sleeve can be provided with one side for placing the tooth occlusion acquisition unit according to actual needs, or the two sides are provided with the tooth occlusion acquisition unit, so that the thickness of teeth can be effectively reduced, and the measurement precision is improved.

The data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, wherein the data filtering unit is used for filtering error data collected by the sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit to output a two-dimensional data table, the database is used for storing detection data and standard data, and the standard data are all data of normal teeth.

The film three-dimensional force pressure sensor comprises a control unit, an X-direction capacitor unit group and a Y-direction capacitor unit group, wherein the X-direction capacitor unit group and the Y-direction capacitor unit group are respectively connected with the control unit, the X-direction capacitor unit group and the Y-direction capacitor unit group respectively comprise capacitor unit modules, each capacitor unit module adopts a comb-shaped structure consisting of more than two strip-shaped capacitor units, and each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and a sensing electrode of a lower polar plate. The capacitance unit module comprises more than two widths a₀Length b₀A first strip capacitor unit group consisting of strip capacitor units and more than two widths ka₀Length b₀And the second strip capacitor unit group is formed by the strip capacitor units. The width of the driving electrode and the width of the induction electrode of each strip-shaped capacitor unit are the same, the length of the driving electrode is greater than that of the induction electrode, and left difference positions delta are reserved at two ends of the length of the driving electrode respectively_{Left side of}And the right difference position delta_{Right side}，b_{0 drive}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein b is_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitance unit. The difference delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the medium, G is the shear modulus, τ, of the elastic medium_maxThe maximum stress value. The comb-shaped structure comprises more than 20 strip-shaped capacitor units and leads connected with the strip-shaped capacitor units in a one-to-one correspondence manner, and an electrode distance a is arranged between every two adjacent strip-shaped capacitor units_δ. The parallel plate area S ═ M (a)₀+2a_δ+ka₀)b₀A/2, wherein M is the number of strip-shaped capacitor units, b₀Is the length of the strip-shaped capacitor unit, a₀The width of the strip-shaped capacitor unit. The strip-shaped capacitor unit leads of the first strip-shaped capacitor unit group and the second strip-shaped capacitor unit group are connected in parallel or independently connected to the control unit. Width of the strip-shaped capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium. And intermediate converters are arranged between the first strip-shaped capacitor unit group and the control unit and between the second strip-shaped capacitor unit group and the control unit, and are used for setting transmission coefficients of voltage to capacitance or frequency to capacitance.

1. Conversion characteristics of strip-shaped capacitor unit

(1) Excitation signal and coordinate system

The strip-shaped capacitor unit is arranged in a rectangular coordinate system shown in FIG. 2, and the length b of the plane of the polar plate₀Width a₀Thickness d of medium₀. The three-dimensional excitation is applied to the outer surface of the capacitor plate, and the generated contact type acting force has three directional components of Fx, Fy and Fz, the acting directions of the Fx and the Fy are along the X axis and the Y axis, and the acting direction of the Fz is along the OZ axisThe direction, normal direction and tangential direction stress are both stress tensors, and capacitance response can be output from the space between leads of the electrodes; normal stress sigma_nFn/A, wherein A ═ a₀·b₀The pole plate is a normal force bearing surface, and Fn is a normal component; generating paired tangential stresses tau on both side surfaces_x＝Fx/A，τ_y＝Fy/A。

According to Hooke's law, σ, in elastic mechanics_nAnd τ_x，τ_yA corresponding deformation of the elastomer will occur. Wherein,

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

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

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

wherein E is the Young's modulus (unit: GN/m) of the elastic medium²) G is the shear modulus of the elastic medium (unit: GN/m²) δ n is the normal displacement of the elastic medium (unit: μ m), and δ x and δ y are relative misalignments of the upper and lower plates of the capacitor (unit: μ m) with signs determined by the coordinate axis orientation.

(2) Capacitance formula and input-output characteristics thereof

The initial capacitance of a rectangular parallel plate capacitor is:

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

in the formula, epsilon₀The electric constant of the vacuum medium is 8.85PF/m, epsilon_r2.5 is the relative permittivity of the dielectric. d₀Receive sigma_nIs excited to produce a relative deformation epsilon_n＝δ_n/d₀＝σ_nE, substituting into (4) to obtain input/output characteristics

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

(3) Linearity and sensitivity under normal stress

a. Degree of normal linearity

In the formula (5), F_nIn the denominator, therefore C_n＝f(F_n) Is non-linear due to the maximum value σ in the conversion range_nmaxε compared with the dielectric elastic constant E_nIs a very small quantity, i.e. epsilon in the denominator_n<<1, expanding (5) according to a series and omitting high-order infinitesimal more than quadratic, wherein the formula (5) can be simplified as follows:

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

can be seen in C_nAnd F_nThe maximum relative error of the normal linearity in the conversion characteristic of (a) is close to zero.

b. Sensitivity of the probe

Definition of sensitivity by Normal

The linear sensitivity can be obtained according to the formula (6),

S_n1＝C₀/AE＝ε₀ε_r/d₀E(7)

and according to the formula (5)

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

S_n2With F_nAnd is changed to F_nThe greater, S_n2The larger, the slightly non-linear over the entire conversion characteristic.

(4) Tangential stress tau_xAnd τ_yCapacitance change under excitation

Tangential stress tau_xAnd τ_yWithout changing the geometric parameters b of the plates₀And a₀To the thickness d of the medium₀Nor is it affected. However tau_xAnd τ_yThe space structure of the strip-shaped capacitor unit is changed, and dislocation offset occurs between the upper and lower electrode plates facing in the forward direction. Taking OX direction as an example, the plate is at tau_xOffset delta under action_x。

In FIG. 3 when τ is_xIs zero, a_{0 is on}＝a_{0 is lower}Are aligned, effective cross-section A between the substrates_τ＝a₀·b₀(ii) a In FIG. 4, at τ_xUnder the action of the right direction, the upper polar plate generates right dislocation deviation delta relative to the lower polar plate_xSo as to make the effective area A between the upper and lower polar plates when calculating the capacitance_τ＝(a₀-δ_x)·b₀(ii) a In FIG. 5, when τ is_xIn the left direction, the misalignment is shifted by δ_xThen to the left and A_τ＝(a₀-δ_x)·b₀，τ_xThe reduction in effective area is the same in the left and right directions, resulting in a capacitance of:

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

according to shearing Hooke's law

${\mathrm{\&tau;}}_x={\mathrm{\&gamma;}}_x\&CenterDot;G=G\&CenterDot;{\mathrm{\&delta;}}_x/d_0---\left(10\right)$

Substituting (10) into (9) to 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) The formula is the input-output characteristic under shear stress, C_τAnd τ_xIn a linear relationship.

And its sensitivity

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

Analyses similar to equations (9) - (12) are equally applicable to τ_yAnd C_τyThe characteristic and technical index of (1) are merely long side b of the strip-shaped capacitor unit₀Should be arranged in the direction of the OX axis and its short side a₀In the OY direction.

2. Contact parallel plate capacitor design

(1) Planar design of parallel plate capacitor

Set original index normal maximum contact stress sigma_nmax200Kpa, if the normal force A is square 10X 10mm²Then maximum normal force F_ZmaxIs σ_nmaxA ═ 20N. Tangential maximum contact stress τ_max70Kp, and the stressed cloth distribution surfaces of the tangential stress are all 10 multiplied by 10mm²The maximum tangential force component F_xmax＝F_ymax＝τ_max·A＝7N。

The structural changes of the strip-shaped capacitor units shown in fig. 4 and 5 are only illustrated in the description of the capacitor output and the tangential stress ± τ_xThe capacitance increment is negative in the input relation, so that the initial capacitance structure is not suitable for being used for +/-T_xA response of increasing or decreasing capacitance is obtained. Therefore, the utility model adjusts the initial structure of the upper and lower electrode plates of the strip-shaped capacitor unit, and the width is a₀And ka₀The strip-shaped capacitor units form a pair of capacitor unit pairs (C)_LAnd C_R) As shown in fig. 6.

In FIG. 6, capacitor cell C_LAnd C_RElectrode size b₀、d₀Are all the same, and have a width of₀One is ka₀Where k is a constant, preferably an integer greater than 1. When tau is_xWhen equal to 0, C_L＝C₀，C_R＝kC₀On the basis of this as in F_xExcited to produce delta_xWill result in the offset effect shown in fig. 4 or 5.

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

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

C_LAnd C_RThe capacitor unit pairs are positioned at the same T_xWill generate delta_xAnd Δ C_τIn response to (2).

Thus, equation (11) can be modified to

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

In the formula,the initial capacitance when the shear stress is zero, the above formula is the shear stress input-output characteristic, C_τxAnd F_xIs a linear relationship, and the sensitivity thereof

See the electrode plan layout of FIG. 7, at a 10X 10mm²The center of the substrate is divided into four quadrants, namely an upper right first quadrant I, an upper left second quadrant II, a lower left third quadrant III and a lower right fourth quadrant IV, wherein the quadrants I and III are opposite to tau_xThe capacitor units responding to the combination, and quadrants II and IV are corresponding to tau_yA combination of responsive capacitive cells. The peripheral line is 10X 10mm²The hatched parts represent the cross sections of the outer molds of the lost wax casting process. And taking the position of the induction electrode on the lower PCB substrate as a reference, and arranging the driving electrode on the upper PCB substrate by taking the edge line of the PCB substrate as a reference. The four dotted line boxes in the figure are the reference of the induction electrodes on the lower polar plate, and the difference between the induction electrodes and the geometric reference line is delta₀(0.1mm)。

The capacitance unit module adopts a comb structure, the capacitance unit module adopts a comb-shaped structure consisting of more than two strip-shaped capacitance units, and each strip-shaped capacitance unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate. From the formula (12) a₀The smaller the sensitivity of the tangential stress response, the greater the single cell is elongated. Let each strip-shaped capacitor unit have a width₀The width of the slot between two strip capacitors is a_δThe pitch of each strip-shaped capacitor unit is ka₀+a₀+2a_δ. To make full use of the planar space of a square substrate, M (ka)₀+a₀+2a_δ)b₀The area of a square substrate is approximately equal to 1, M is the number of strip capacitors, and then M (ka) is obtained₀+a₀+2a_δ) 20mm, wherein the groove width a_δIt should not be too large, otherwise it is not favorable to use the effective planar space on the substrate, and it should not be too small, and it should be constrained by the lost wax casting process. For normal sensitivity S_nAnd tangential sensitivity S_τEquality, according to equations (7) and (12), let a₀·G＝d₀E, when d₀When k is 0.1mm and k is 1.5, M can be determined.

To realize tau_xAnd τ_yThe tangential responses do not mutually influence, and the difference delta is reserved at the two ends of the length of the driving electrode of the strip-shaped capacitor unit₀Thus b is_{0 drive}＝b_{0 bottom}+2·δ₀Wherein in b_{0 drive}The length reservation difference of two ends should be theoretically ensured ${\mathrm{\&delta;}}_0\&GreaterEqual;d_0\&CenterDot;\frac{{\mathrm{\&tau;}}_{\max }}{G},$ Calculated value thereof 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, it should be ensured in terms of process b_{0 drive}－b_{0 bottom}Not less than 0.01 mm. Thus ensuring tau when calculating normal capacitance output response_xAnd τ_yWithout any effect on the normal capacitance response.

To realize tau_xAnd τ_yHas no influence on normal capacitance response and has a width of₀And ka₀The strip-shaped capacitor units form a pair of capacitor unit pairs (C)_LAnd C_R) And performing public calculation to eliminate mutual influence. Guarantee of tau_xGenerating pairs tau in I, III quadrant capacitance unit_xAnd the capacitance response of the unit generates the counter tau in the II and IV quadrants_yTo ensure that the capacitive cells in the four quadrants are at τ_xAnd τ_yTwo groups of differential capacitance pairs can be generated under tangential excitation.

(2) Calculation of normal and tangential forces

Let the width be a in FIG. 6₀When the strip-shaped capacitor unit is subjected to a tangential force tau_xGenerating a tangential displacement d_xThe output capacitance value is C₁Width of ka₀When the strip-shaped capacitor unit is subjected to a tangential force tau_xGenerating a tangential displacement d_xThe output capacitance value is C₂Then, there are:

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

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

obtained from (15) to (16):

$C_1-C_2=\frac{{\mathrm{\&epsiv;a}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;ka}}_0{b}_0}{d_n}$ and calculating to obtain:

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

from (15) × k- (16):

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

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

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

Therefore, the following steps are carried out: $F_n=\frac{\left(d_n-d_0\right)E\&CenterDot;S_0}{d_0}$

by $\frac{d_x}{d_0}=\mathrm{\&gamma;}=\frac{\mathrm{\&tau;}}{G}=\frac{F_{\mathrm{\&tau;}}}{G\&CenterDot;S_0},$ Therefore, it is not only easy to use $F_{\mathrm{\&tau;}x}=\frac{{\mathrm{GS}}_0{d}_x}{d_0}.$

In the above formula, either the normal excitation F_nOr tangential excitation F_yAll are not to O_τAn influence is produced. I.e. automatically eliminating sigma_nAnd τ_yFor tau_xBecause the equivalent and signed capacitance changes are automatically cancelled in all operations where the signals contain a subtraction. And F_yAnd F_xTo sigma_nCan pass through the upper electrode at b₀Direction increased geometric length 2 delta₀And (4) eliminating. In the same way, F can be obtained_τy。

(4) Choice of main material and its characteristic parameters

The cross-sectional view of the structure of the comb-shaped parallel plate capacitor is similar to the sandwich structure shown in fig. 9, 1 is an upper PCB substrate, 2 is a lower PCB substrate, 3 is a driving electrode, 4 is an induction electrode, and 5 is an elastic medium. Distance d between the plates₀Except for the copper foil electrodes, the inner spaces of the upper and lower substrates were made of PDMS (polydimethylsiloxane) super-elastic insulating medium filled by lost wax casting. Its mechanical and physical parameters are Young's modulus E equal to 6.2MPa, shear elastic modulus G equal to 4.1MPa, and relative dielectric constant epsilon of medium polarization_y2.5. Since E and G of the medium are much smaller than the elastic modulus E of copper_Steel103GPa, the internal dielectric of the capacitorThe deformation under stress is much larger than the deformation of the plate.

(5) Electrode lead design

Both the driving electrodes and the sensing electrodes need to be provided with lead-out wires, and considering that each driving electrode is grounded on a signal level, four groups of driving electrodes only need to share one lead-out wire. The induction electrodes of the four first strip-shaped capacitor unit groups and the four induction electrodes of the second strip-shaped capacitor unit groups need to use independent outgoing lines, so that the whole capacitor assembly has at least 5 pins which are led out from the side surface of the planar package, and the four induction electrodes refer to the fact that the width in the X direction is a₀And a width of ka₀And a width in the Y direction of a₀And a width of ka₀So that the top and bottom outer surfaces of the entire assembly can be easily brought into contact with the measurement object. The utility model discloses under the support of new material and new technology, accomplished the design of a novel three-dimensional force sensitive capacitor combination, at 10X 10mm²The stress surface can transmit the stress to the medium more uniformly in the normal direction or the tangential direction. The four unit capacitors are distributed in two pairs. In the contact of space force and the surface of the sensor, the external force is only 1, the capacitance response is 4, the whole electrode plate contributes to solving Fn, and simultaneously, two pairs of capacitors are combined to form a system, and F can be obtained_xAnd F_yThereby completely describing a three-dimensional force.

The present invention has been described above with reference to the accompanying drawings, and it is obvious that the present invention is not limited by the above-mentioned manner, and various insubstantial improvements can be made without modification to the method and technical solution of the present invention, or the present invention can be directly applied to other occasions without modification, all within the scope of the present invention. The protection scope of the present invention shall be subject to the protection scope defined by the claims.

Claims (10)

1. The tooth comprehensive measuring instrument based on the detachable tooth socket is characterized by comprising a tooth occlusion collecting unit, a tooth looseness collecting unit, a tooth socket, a data collecting card, a data processing unit, a wireless communication unit and a controller, wherein the tooth occlusion collecting unit and the tooth looseness collecting unit are installed on the tooth socket, the data collecting card collects data of the tooth occlusion collecting unit and the tooth looseness collecting unit, the data processing unit processes information collected by the data collecting card and sends the information to the controller, the data processing unit and the wireless communication unit are respectively connected with the controller, the wireless communication unit is communicated with a remote receiving unit, the tooth occlusion collecting unit and the tooth looseness collecting unit both adopt film three-dimensional force pressure sensors, and each film three-dimensional force pressure sensor comprises a control unit, a data acquisition unit and a controller, The capacitor comprises an X-direction capacitor unit group and a Y-direction capacitor unit group which are respectively connected with a control unit, wherein the X-direction capacitor unit group and the Y-direction capacitor unit group respectively comprise capacitor unit modules, each capacitor unit module adopts a comb-tooth-shaped structure consisting of more than two strip-shaped capacitor units, and each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate.

2. The comprehensive dental measuring instrument according to claim 1, wherein the dental ferrule comprises a side sleeve and a bottom sleeve, the side sleeve and the bottom sleeve are detachably connected, the dental looseness collecting unit is mounted on the side sleeve, and the dental occlusion collecting unit is mounted on the bottom sleeve.

3. A comprehensive dental measuring instrument as claimed in claim 2, wherein the bottom cover comprises bottom cover clamping pieces detachably connected with each other, bottom cover clamping structures for clamping and acquiring the tooth occlusion are respectively arranged on the upper and lower surfaces of the bottom cover clamping pieces, the side cover comprises side cover clamping pieces detachably connected with each other, a side cover clamping device for clamping and acquiring the tooth looseness is arranged on one side of each side cover clamping piece, and a clamp and a device seamlessly connected with the teeth are arranged on the other side of each side cover clamping piece.

4. The comprehensive tooth measuring instrument according to claim 1, wherein the data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, the data filtering unit is used for filtering error data collected by the sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit to output a two-dimensional data table, and the database unit is used for storing detection data and standard data, wherein the standard data are normal tooth data.

5. A dental comprehensive measuring instrument according to claim 1, wherein the capacitance unit module comprises more than two widths a₀Length b₀A first strip-shaped capacitor unit group consisting of strip-shaped capacitor units and more than two widths ka₀Length b₀And the second strip-shaped capacitor unit group is formed by the strip-shaped capacitor units.

6. A comprehensive dental measuring instrument as claimed in claim 1, wherein the driving electrode and the sensing electrode of each strip-shaped capacitance unit have the same width, the length of the driving electrode is greater than that of the sensing electrode, and a left difference δ is reserved at each end of the driving electrode_{Left side of}Sum right difference delta_{Right side}，b_{0 drive}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein b is_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitor unit is delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the dielectric of the strip-shaped capacitor unit, G is the shear modulus of the elastic dielectric, tau_maxThe maximum stress value.

7. A comprehensive dental measuring instrument as claimed in claim 1, wherein the comb-like structure includes more than 20 strip-like capacitor units, leads connected with the strip-like capacitor units in a one-to-one correspondence manner, and an inter-electrode distance a is provided between two adjacent strip-like capacitor units_δThe parallel plate area S ═ M (a)₀+2a_δ+ka₀)b₀A/2, wherein M is the number of strip-shaped capacitor units, b₀Is the length of the strip-shaped capacitor unit, a₀The width of the strip-shaped capacitor unit.

8. A dental comprehensive measuring instrument according to claim 5, characterized in that the strip-shaped lead wires of the first and second strip-shaped capacitor cell groups are connected to the control unit in parallel or independently.

9. A dental comprehensive measuring instrument according to claim 5, characterized in that the width of the strip-shaped capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium.

10. A dental comprehensive measuring instrument according to claim 5, wherein intermediate converters are respectively arranged between the first strip-shaped capacitor cell group and the control unit, and are used for setting transmission coefficients of voltage to capacitance or frequency to capacitance.