CN105054953A - Clinical treatment effect evaluation system based on sole pressure distribution - Google Patents

Abstract

The invention relates to a clinical treatment effect evaluation system based on sole pressure distribution, comprising a sole three-dimensional pressure measurer body and a sensing system signal processor. The sole three-dimensional pressure measurer body is internally provided with a plurality of capacitive pressure sensors used for receiving sole pressure information; the capacitive pressure sensors comprise an X-directional differential capacitive unit combination and a Y-directional differential capacitive unit combination; both the X-directional differential capacitive unit combination and the Y-directional differential capacitive unit combination comprise more than two mutually differential capacitive unit modules; each capacitive unit module is in a triangular structure composed of more than two strip capacitors. Forces of the foot in x, y and z directions can be detected by the three-dimensional pressure sensors, sole three-dimensional pressure data are used for clinical observation, disease degree measurement, postoperative treatment effect evaluation, and biomechanic and rehabilitation study; a measurement method is convenient and simple.

Description

Based on the clinical therapeutic efficacy evaluation system that plantar nervous arch is measured

Technical field

The invention belongs to technical field of medical instruments, relating to a kind of apparatus for evaluating medicinal therapeutic effect, be specifically related to a kind of clinical therapeutic efficacy evaluation system measured based on plantar nervous arch.

Background technology

Human Sole pressure distribution reflects structure, the situation such as function and whole body gesture control about foot.Testing and analysis plantar pressure can obtain physiology, pathomechanics parameter and the function parameter of human body under each figure and motion, and this is all significant to clinical diagnose, disease degree mensuration, postoperative curative effect evaluation, biomechanics and rehabilitation research.Dynamic plantar pressure measxurement is important quantitative check and analysis means, is with a wide range of applications.At present abroad, this technology has been used in the inspection of the perioperative function of artificial joint and efficacy evaluation, trunk and lower-limb ailments and has followed up a case by regular visits to, provides for artificial limb and Artificial Joint Design in data, rehabilitation training and the analysis and inspection of athletic training, the early prediction of diabetic foot and treatment etc.

Foot ulcers is one of severe complication of diabetes, and diabetics amputation and the dead danger of suffering from foot ulcers obviously increase.Because peripheral neuropathy causes plantar pressure to increase, the increase of long term mechanical pressure makes foot ulcers occur.Existing more foreign literature proves that dynamic plantar pressure anomaly increases obviously relevant to the generation of diabetes plantar ulcer.

Existing foot force data acquisition unit adopts pressure transducer, but these pressure transducers be all the pressure gathered on vertical direction: as Chinese patent CN201110074892.6 employing is the diaphragm pressure sensor of 10 corresponding foot force distributed points; What CN201010230489.3 adopted is the matrix pressure transducer of 8 row × 10 row, and what CN2012102984097 adopted 40 is multiplied by 40 varistor matrixes; But we know in the process of walking, the power between vola and acting surface also has in horizontal direction.Power on independent collection vertical direction is not enough to the active force reacting sole and acting surface.

Summary of the invention

In order to overcome the deficiencies in the prior art, the invention provides a kind of clinical therapeutic efficacy evaluation system measured based on plantar nervous arch, by carrying out ingenious setting to capacitance pressure transducer, structure, measuring the three-dimensional pressure in vola, and by introducing differential capacitor, eliminate retinoic acid syndrome.

Technical scheme of the present invention is: a kind of clinical therapeutic efficacy evaluation system measured based on plantar nervous arch, comprise vola three-dimensional pressure measuring device body and sensor-based system signal processor, the multiple capacitive pressure transducers accepting plantar pressure information are arranged in the three-dimensional pressure measuring device body of vola, described capacitive pressure transducer comprises X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination, described X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination include two or more and mutually form differential capacitor cell module, described capacitor cell module adopts the triangular comb teeth 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, the normal force of the electric capacity read group total capacitance sensor of described X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination and eliminate tangential force impact.

Vola three-dimensional pressure measuring device body from top to bottom comprises and recovers froth bed, sensor layer, the substrate layer of elastic material, trace layer and hard backing plate, recovering froth bed selects polyurethane foam, silicon foams or modified organic silicon to fill inorganic short fiber, trace layer lead-in wire is by parallel way or be independently connected to sensor-based system signal processor, the upper surface of vola three-dimensional pressure measuring device is rectangle, width 45 centimetres ~ 1 meter, length 3 meters ~ 5 meters.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.Described two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.The lead-in wire that described triangular 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+ a _δ) * b ₀/ 99%, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell, a _δfor the electrode spacing of strip capacitor cell.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.Be provided with intermediate translator between described sensor-based system signal processor and capacitor cell module, changer is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.Described sensor system signals processor comprises multiple signals high speed commutation circuit, A/D translation circuit and control circuit, described high speed commutation circuit comprises three grades of commutation circuits, the output of previous stage commutation circuit is the input signal of next stage commutation circuit, and afterbody commutation circuit sends into control circuit through A/D translation circuit.

The present invention has following good effect: utilize three-dimensional force pressure transducer, the power of foot in x, y, z three directions can be detected, vola three-dimensional pressure data are used for clinical observation, disease degree mensuration, postoperative curative effect evaluation, biomechanics and rehabilitation research, assay method is convenient and simple.The present invention measures on the basis of three-dimensional force at capacitance sensor, effectively uses dull and stereotyped effective 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

Fig. 1 is specific embodiment of the invention strip capacitor cell and coordinate system thereof;

Fig. 2 is the strip capacitor cell schematic diagram of the specific embodiment of the present invention;

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

Fig. 4 is the strip capacitor cell left-hand skew schematic diagram of the specific embodiment of the present invention;

Fig. 5 is that specific embodiment of the invention differential capacitor is to initial dislocation figure;

Fig. 6 is specific embodiment of the invention differential capacitor at τ _xdislocation figure under excitation;

Fig. 7 is the signal flow graph of specific embodiment of the invention normal direction excitation summation;

Fig. 8 is that the specific embodiment of the invention tangentially encourages differential signal flow graph;

Fig. 9 is specific embodiment of the invention comb teeth-shaped plane-parallel capacitor cross-section structure;

Figure 10 is the profile of specific embodiment of the invention sole pressure distribution measurer;

Figure 11 is the electrode position figure of specific embodiment of the invention pressure transducer;

Figure 12 is the electrode arrangement of specific embodiment of the invention pressure transducer;

Figure 13 is A place enlarged drawing in Fig. 3;

Figure 14 is the top crown plane design drawing of specific embodiment of the invention pressure transducer;

Figure 15 is the bottom crown plane design drawing of specific embodiment of the invention pressure transducer;

Wherein, 1, recover froth bed, 2, sensor layer, 3, substrate layer, 4, trace layer, 5, backing plate, 6, pin interfaces plate, 7, induction electrode, 8, drive electrode, 9, upper PCB substrate, 10, lower PCB substrate.

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.

Main thought of the present invention is: clinical therapeutic efficacy evaluation system of the present invention comprises vola three-dimensional pressure measuring device body and sensor-based system signal processor two parts, the multiple flat capacitor pressure transducers accepting plantar pressure information are arranged in the three-dimensional pressure measuring device body of vola, sensor-based system signal processor is used to the control circuit gathering vola three-dimensional pressure measuring device ontology information, has come the collection of plantar pressure information, process and transmission; Finally noise reduction process is carried out to signal, increase signal to noise ratio, make the signal that collects reliably effective.

As shown in Figure 10, for the structure chart of vola of the present invention three-dimensional pressure measuring device, measuring device comprises recovery froth bed, sensor layer, substrate layer, trace layer, raft and pin interfaces plate, the bottom is the backing plate that hard material makes, the superiors are for recovering froth bed, the thickness of foam is 20mm-30mm, recovers foam and selects polyurethane foam, silicon foams, modified organic silicon to fill the materials such as inorganic short fiber.Be sensor layer under recovering froth bed, being substrate layer under sensor layer, is trace layer under substrate layer, sensor and lead-in wire is arranged on different layers and just avoids the two interference mutually, the sensor lead access pin interfaces plate of trace layer.Substrate layer is elastomeric matrices material; it can be elastomeric material; capacitance pressure transducer, stressor layer sensor layer is arranged on the substrate layer of elastic material and recovers between froth bed; substrate layer and the recovery froth bed of elastic material are all flexible materials; can play a protective role to pressure transducer, make uniform force.The upper surface of measuring device is rectangle, width 45 centimetres to 1 meter, and length 3 meters to 5 meters, facilitates testee to walk about above, not only can change by monitoring station pressure immediately, also can monitor the pressure change in the vola when normal ambulation.

As Figure 11-15, for the electrode plate structure figure of pressure transducer of the present invention, Figure 11 is the structure chart of upper bottom crown overlap, in figure, what dotted line represented is bottom crown, and what solid line represented is top crown, and Figure 11 is mainly in order to represent to stagger and the position of electrode in the position of upper bottom crown, what triangle represented is the appearance profile that pole plate forms, and the shape of pole plate is as Figure 12-15.

Pressure transducer comprises X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination, each combination includes two or more and mutually forms differential capacitor cell module, capacitor cell module adopts and forms triangular comb teeth structure by plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.The drive electrode of each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length.Two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.The lead-in wire that 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.Parallel-plate area S=M (a ₀+ a _δ) b ₀/ 99%, wherein, bar M is strip electric capacity quantity, b ₀for the length of strip electric capacity, a ₀the width of strip electric capacity.The width of described strip electric capacity wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.Be provided with intermediate translator between sensor-based system signal processor and capacitor cell module, changer is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.The each strip capacitor cell lead-in wire of capacitor cell module is by parallel way or be independently connected to pin interfaces plate.

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. 1, 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, the action direction of Fx and Fy along X-axis and Y-axis, the action direction of Fz along OZ axle, namely direction, normal direction and tangential stress are a kind of stress tensor, from can the response of output capacitance 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 electric dielectric 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 plane-parallel capacitor, 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 fig. 2 _xwhen being zero, a _{on 0}=a _{0 time}just right, effective cross-section A between substrate _τ=a ₀b ₀; In figure 3, 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. 4, work as τ _xduring for left-hand, dislocation skew δ _xthen left, A _τ=(a ₀-δ _x) b ₀, 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 rectangular capacitive sensor in formula ₀oX direction of principal axis should be arranged at, and its minor face a ₀then in OY direction.

(5) introduction of differential capacitor unit

Capacitor arrangement change shown in Fig. 3 and Fig. 4, 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 capacitor for this reason, forms pair of differential electric capacity to (C _lwith C _r), specifically as shown in Figure 5.

In Fig. 5, a pair electric capacity C _land C _relectrode size a ₀, b ₀, d ₀all identical, initial dislocation skew δ ₀also identical, difference is left side capacitor C _lupper strata δ ₀wedge angle be oriented to+OX, and the right capacitor C _rupper strata δ ₀wedge angle sensing-OX.

Work as τ _xwhen=0, $C_L=C_R=C_{{\mathrm{\&tau;}}_x}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;\left({\mathrm{\&delta;}}_0\right)\&CenterDot;b_0}{d_0},$ Namely the electric capacity in figure corresponding to dash area, on this basis as at-F _xlower generation ± the δ of excitation _xmistake skew, formed as shown in Figure 6 electric capacity increase and decrease effect.

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

C in Fig. 6 _land C _rdifferential capacitor is to same τ _xby generation ± δ _xwith ± Δ C _τresponse.

δ ₀size should meet desirable δ ₀=10 μm, thus, formula (11) can be revised as

$C_{\mathrm{\&tau;}x}=C_{\mathrm{\&tau;}0}\&PlusMinus;\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}{F}_x---\left(14\right)$

In formula, for initial capacitance when shearing stress is zero, (14) formula is shearing stress input-output characteristic, C _{τ x}with F _xlinear relationship, and its sensitivity

2, contact parallel plate capacitor design

(1) planar design of parallel plate capacitor

Arrange, at a 10 × 10mm see the electrode plane in Figure 11, Figure 12, Figure 14 and Figure 15 ²substrate center do cross separate, form four regions I, II, III, IV, wherein I, II region is to τ _ymake the differential capacitor unit combination of response, and III, IV region is to τ _xmake the differential capacitor unit combination of response.

Object-line is 10 × 10mm ²pcb board four edge lines, answer clean cut accurate with what ensure in shape and size to PCB substrate.Hachure part represents the outer mode cross section of wax-loss casting process, and its geometry and size also should keep precisely when mechanical-moulded, tears open, more should maintain dimensional accuracy for being convenient in demoulding and can spelling, finally to ensure the mutual interference that elimination three-dimensional force responds electric capacity.

Capacitor cell module adopts the triangular comb teeth shape 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 electric capacity is strip.If every root strip capacitor cell is wide is a ₀, the groove width between two strip capacitor cells is a _δ, then the pitch of every root strip capacitor cell is a ₀+ a _δ.In order to make full use of the plane space of square substrate, make N (a ₀+ a _δ) b ₀≈ 1/4 square substrate surface area, N is the strip capacitor cell number in each region, then have N (a ₀+ a _δ)=5mm, 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 _τ, by formula (7) and (12), make a ₀g=d ₀e, works as d ₀during=0.1mm, then a ₀=0.15mm, if make a _δ=0.05mm, then N=25.Therefore, the strip capacitor cell M of whole pole plate is 100.

In order to realize τ _xand τ _ybetween tangential response mutually do not have an impact, δ is reserved at drive electrode length two ends ₀, therefore b _{0 drives}=b _{0 end}+ 2 δ ₀, wherein at b _{0 drives}two ends length is reserved should be ensured in theory ${\mathrm{\&delta;}}_0\&GreaterEqual;d_0\&CenterDot;\frac{{\mathrm{\&tau;}}_{y\max }}{G},$ 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.τ can be ensured like this when computing method exports response to electric capacity _xand τ _yany impact is not produced on the response of normal direction electric capacity.

In order to realize τ _xand τ _yany impact is not produced on the response of normal direction electric capacity, drive electrode and the horizontal layout of induction electrode in each region of each strip electric capacity should ensure that certain dislocation offsets, as got 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.And put they and geometry datum line differential apart from being δ ₀(0.1mm), to ensure τ _yproduce differential capacitor at I, II area capacitance unit and export response, then produce τ at III, IV area capacitance unit _xdifferential capacitor response, an initially dislocation skew δ is set _xo, its value should ensure its value of calculation and δ ₀similar, its skew that initially misplaces all arranges δ _xo=δ _yo=0.01mm, to ensure that capacitor cell in four regions is at τ _xand τ _ytwo groups of differential capacitors pair can be produced under tangential excitation.

(2) normal stress calculates

The normal direction can being rewritten single capacitor by formula (6) responds electric capacity

$C_{ni}=N(C_0+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_{r\&CenterDot;Fn}}{d_{0}E})---\left(15\right)$

Wherein, i=I, II, III, IV, because of in each region, N is the quantity of the strip capacitor cell in each region, and N number of strip capacitor cell is in parallel.

As sued for peace again, can obtain above formula is σ _nelectric capacity overall response.

Although the summation of single electric capacity is connected in parallel realization by contact conductor.But once and connect, just no longer can realize asking subtractive combination, the summation combination on historical facts or anecdotes border will be sued for peace by the output of intermediate translator again, sees Figure 10, the signal flow block diagram of summation.

In figure, intermediate translator K can be voltage to electric capacity or frequency to the transmission coefficient of electric capacity, thus completes the synthesis to normal direction response.

$O_n=4KN(C_0+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;Fn}{d_{0}E})---\left(16\right)$

(3) tangential stress calculates

C _ito C _iIand C _iIIto C _iVtwo can be realized to differential combination, see Figure 11, through differential technique process, the overall response of differential output

$O_{\mathrm{\&tau;}x}=\frac{2{\mathrm{NK\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{a_{0}G}{F}_x---\left(17\right)$

In above formula, no matter be normal direction excitation F _nor tangentially encourage F _yall not to O _{τ x}have 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 all automatically eliminating with the capacitance variations met.And F _yand F _xto σ _ninterference by upper electrode at b ₀direction increases geometrical length 2 δ ₀eliminate, in like manner can in the hope of O _{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.In Fig. 9,9 and 10 is upper and lower PCB substrate, and 8 is the drive electrode Copper Foil of sticker in PCB substrate, and 7 is the induction electrode Copper Foil on underlying substrate.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.Four induction electrodes then need, with respective independently lead-out wire, to draw, so that whole assembly top and bottom outer surface can contact with measuring object easily so whole capacitance component has at least 5 pins from the side of planar package.

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, four capacitor cell modules be two to distribute to combination.In the contact of non-coplanar force and sensor surface, external force only has 1, and electric capacity response but has 4, and can obtain the information of normal direction Fn to 4 electric capacity summations, namely whole battery lead plate is all to asking Fn to contribute, and simultaneously by two pairs of capacitor combinations composition differential systems, can obtain F again _xand F _yinformation, thus complete description three-dimensional force.

Capacitance pressure transducer, is arranged in substrate layer uniformly according to matrix form and recovers between froth bed, capacitor plate is connected with sensor system signals processor by circuit lead, sensor system signals processor comprises multiple signals high speed commutation circuit, A/D translation circuit and control circuit, in order to save A/D translation circuit, the measurement of multichannel pressure transducer is completed with a road A/D translation circuit, multiple signals high speed commutation circuit and control circuit are the design key of system, and switch speed has influence on the data volume of testing in of short duration gait processes.The Acquisition Circuit of the present invention's design carries out signal switching to No. 256 sensors simultaneously.From the control system of control circuit after local shaping, divide three grades to switch, the first order uses 32 8 road switch concurrent workings, export 32 road signals, 32 road signals enter second level switch, adopt 48 road switch concurrent workings, obtain 4 road signals, this 4 road signal enters third level switch, obtains 1 road signal, enters A/D translation circuit.Data are read in computer temporary by A/D translation circuit in conversion process, and after all digital independent complete, preservation in a computer.

In actual use, by pressure-detecting device tiling on the ground, testee walks about with normal gait above or stands still, gauge respectively gathers three dynamic plantar pressure and three static plantar pressures, contrast with the plantar pressure of normal person, by the respective average pressure in eight regions, three test analysis volas, heel, arch of foot, 1st head of metatarsal bone, 2nd head of metatarsal bone, 3rd ~ 5 head of metatarsal bone, 1st toe, 2nd toe, 3rd ~ 5 toes, the data of sole pressure test are for analyzing, diagnose and set up expert aid decision-making system and reference frame is provided, reference frame is provided to clinical therapeutic efficacy evaluation.

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 clinical therapeutic efficacy evaluation system measured based on plantar nervous arch, it is characterized in that, comprise vola three-dimensional pressure measuring device body and sensor-based system signal processor, the multiple capacitive pressure transducers accepting plantar pressure information are arranged in the three-dimensional pressure measuring device body of vola, described capacitive pressure transducer comprises X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination, described X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination include two or more and mutually form differential capacitor cell module, described capacitor cell module adopts the triangular comb teeth 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, the normal force of the capacitance read group total capacitance sensor of described X-direction differential capacitor unit combination and Y-direction differential capacitor unit combination and eliminate tangential force impact.

2. clinical therapeutic efficacy evaluation system according to claim 1, is characterized in that, described vola three-dimensional pressure measuring device body from top to bottom comprise recover froth bed, sensor layer, elastic material substrate layer,

Trace layer and hard backing plate, recovering froth bed selects polyurethane foam, silicon foams or modified organic silicon to fill inorganic short fiber, trace layer lead-in wire is connected to sensor-based system signal processor by parallel or independent mode, the upper surface of vola three-dimensional pressure measuring device is rectangle, width 45 centimetres ~ 1 meter, length 3 meters ~ 5 meters.

3. clinical therapeutic efficacy evaluation system according to claim 1, it 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.

4. clinical therapeutic efficacy evaluation system according to claim 3, is characterized in that, 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.

5. clinical therapeutic efficacy evaluation system according to claim 1, it is characterized in that, described two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.

6. clinical therapeutic efficacy evaluation system according to claim 1, it is characterized in that, the lead-in wire that described triangular comb teeth 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.

7. clinical therapeutic efficacy evaluation system according to claim 6, is characterized in that, described parallel-plate area S=M (a ₀+ a _δ) * b ₀/ 99%, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell, a _δfor the electrode spacing of strip capacitor cell.

8. clinical therapeutic efficacy evaluation system according to claim 1, 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.

9. clinical therapeutic efficacy evaluation system according to claim 1, it is characterized in that, be provided with intermediate translator between described sensor-based system signal processor and capacitor cell module, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.

10. clinical therapeutic efficacy evaluation system according to claim 1, it is characterized in that, described sensor system signals processor comprises multiple signals high speed commutation circuit, A/D translation circuit and control circuit, described high speed commutation circuit comprises three grades of commutation circuits, the output of previous stage commutation circuit is the input signal of next stage commutation circuit, and afterbody commutation circuit sends into control circuit through A/D translation circuit.