CN1729955A - Arrangement for monitoring walk-assisting kinetic parameters of walking device - Google Patents

Abstract

The invention discloses a kinetic parameter-monitoring device of walker helper, comprising a walker and a strain gauge. Wherein, the strain gauge is twelve connected strain gauge bridge network for indirectly extracting the HRV information which is mounted outside the handle on the frame of walker; the twelve connected strain gauge bridge network is connected to a amplifying circuit, a analog-to-digital conversion circuit and a computer; the output analogue signal of twelve connected strain gauge bridge network via the amplified by amplifying circuit is transmitted to the analog-to-digital conversion circuit which transforms said analogue signal into digital signal to the computer; and the computer stores a Labview data collecting software and a GUI data processing software. Said invention utilizes the twelve connected strain gauge bridge network mounted on the frame of walker to indirectly extract the HRV information which avoids the handle and eliminates the effect of measuring process on the status of walker at most, for confirming the mutual independence between the measuring method and the measured data and improving the precision and reliability of measurement result.

Description

Arrangement for monitoring walk-assisting kinetic parameters of walking device

Technical field

The present invention relates to the kinetic parameter monitoring of clinical rehabilitation walking aid device, the especially kinetic parameter of walker monitoring.The effective instruction and the rehabilitation efficacy that are applied to relevant assistive device are estimated the field.

Background technology

Walker is a kind of important walking aid device that is used for clinical rehabilitation, can provide the loading of external machinery support of walking disorder patient and minimizing lower limb, as shown in Figure 2.Utilization rate in recent years is remarkable ascendant trend.Show that according to relevant investigation statistics the walker user of the U.S. has just surpassed 1,700,000 people in the early 1990s, and the annual use that on average has nearly 20,000 wound accident to relate to walker, wherein modal damage is exactly hip fracture and upper limb damage.Estimate that by this newly-increased walker in whole world every year is caused injury case when more than 600,000.Though China does not still have concrete statistics, the walker user is acknowledged as one already and needs the special social group who pays close attention to and look after badly.

Understand the dynamic conditions in the walker use, especially in real time differentiate the power demand of its different phase, can verify with tired relevant muscular tremor and show effect between the hazardous area, quantize the walking quality of user, in gait training and daily life, reduce the walker application risk.In addition, because the different gait deformities (for example fracture of tibia and fibula, amputation, hemiparesis, hemiplegia and cerebral palsy) that user exists can cause different walkers to use pattern, also need dynamics research to be screened targetedly, to understand the different demands of user, in designing again, the structure of walker takes in.

(Handle reaction vector HRV) is at present relevant walker walk help kinetic parameter index comparatively commonly used to handle retroaction vector.It is user in the walk help process to be synthesized the effect of walker be reduced to concentrfated load, represent with two mechanics vectors that are positioned at walker handle mid point cross section centre of form place, its component in different directions can characterize user respectively by trying hard to recommend into that walker obtained, dynamic balance and power support level, as shown in Figure 2.Since HRV notion in 1996 proposes, had successively from English, moral, U.S. a plurality of problem group and carried out detection research HRV, method all adopts and strain gauge bridge is directly installed on the walker handle surfaces measures.In this case, because the measuring position concentrates on handle surfaces, foil gauge very easily is subjected to the wet influence of the gentle hands of user hands, causes the decline of certainty of measurement; In addition, the stickup of foil gauge also can bring some hint that does not accommodate psychology of holding action frightened to user on the handle, thereby influences its normal gait, introduces the unknowable wrong factor to follow-up based on dynamic (dynamical) gait analysis.Given this, be necessary to develop the novel arrangement for monitoring walk-assisting kinetic parameters of walking device of a cover, accurately differentiated its power demand in real time, quantized the walking quality, reduced the walker application risk.

Summary of the invention

Technical problem to be solved by this invention is, a kind of arrangement for monitoring walk-assisting kinetic parameters of walking device that can quantize the walking quality, reduce the walker application risk is provided, it is under the prerequisite that does not influence the normal walk help process of user, can accurately differentiate its power demand in real time, for effective instruction of walker and the reliable evaluation of walk help effect are offered help.

Be that arrangement for monitoring walk-assisting kinetic parameters of walking device of the present invention comprises walker and is arranged on foil gauge on the walker for solving the problems of the technologies described above.Described foil gauge is the 12 strain gauge bridge networks that lead, and is used for extracting indirectly HRV information, and it is arranged on the position beyond the described walker framework upper handle; The described 12 strain gauge bridge networks that lead are connected with amplifying circuit, analog to digital conversion circuit and computer; The described 12 output analogue signals of leading the strain gauge bridge network export analog to digital conversion circuit to after amplifying circuit amplifies, analog to digital conversion circuit is that digital signal exports computer to above-mentioned analog signal conversion.

Described Computer Storage has the Labview data acquisition software (based on the data acquisition software of virtual instrument, the formal Chinese full name of Labview is " virtual instrument ") and the gui data process software (based on the data processing software of graphic user interface, the formal Chinese full name of GUI is " graphic user interface "), carry out following steps during described computer run Labview data acquisition software: acquisition channel is set, acquisition length is set, frequency acquisition is set, image data, text storage and oscillography plate monitor; Carry out following steps during described computer run gui data process software: patient's data input, selected pending data file, initialization, HRV calculates, storage, demonstration, double counting and cleaning input, return " selected pending data file " step after the double counting, return " patient's data input " step after the cleaning input.

Compared with prior art, the present invention has following beneficial effect: (one) adopts and to be installed in the strain gauge bridge network that leads of 12 on the walker framework and to extract HRV information indirectly, avoid handle, thereby farthest eliminate the influence of measuring process to the user walking step state, guarantee the mutual independence between measurement means and measurement data, improve the precision and the reliability of measurement result; (2) can be used widely in the effective instruction and the rehabilitation efficacy evaluation field of relevant assistive device.

Description of drawings

Fig. 1 is the system architecture diagram of arrangement for monitoring walk-assisting kinetic parameters of walking device of the present invention;

Fig. 2 is a HRV definition sketch map;

Fig. 3 is the 12 strain gauge bridge network site figure that lead;

Fig. 4 is a machine front cabinet structural representation;

Fig. 5 is based on the date processing interface of GUI;

Fig. 6 is based on the data acquisition software flow chart of virtual instrument (Labview);

Fig. 7 is based on the data processing software flow chart of graphic user interface (GUI).

Reference numeral:

The 1st, phone wire harness 2 is that 220v power line 3 is that 68 needle interfaces 4 are that on and off switch 5 is power supply indicators

The specific embodiment

Below in conjunction with embodiment and accompanying drawing the present invention is elaborated.

As shown in Figure 1, arrangement for monitoring walk-assisting kinetic parameters of walking device of the present invention comprises walker and is arranged on foil gauge on the walker.Described foil gauge is the 12 strain gauge bridge networks that lead, and is used for extracting indirectly HRV information, and it is arranged on the position beyond the described walker framework upper handle; The described 12 strain gauge bridge networks that lead are connected with amplifying circuit, analog to digital conversion circuit and computer; The described 12 output analogue signals of leading the strain gauge bridge network export analog to digital conversion circuit to after amplifying circuit amplifies, analog to digital conversion circuit is that digital signal exports computer to above-mentioned analog signal conversion.Described Computer Storage has Labview data acquisition software and gui data process software.

The present invention is to be installed in the strain gauge bridge network that leads of 12 on the walker framework, relevant hardware and software system have been designed, hardware system comprises senser element, amplifying circuit, regulated power supply and analog-digital commutator four parts composition, and software system comprises data acquisition and processing (DAP) two parts composition.

The HRV that user is applied in walker walk help process can at first be converted into voltage signal by the senser element that is installed on the walker.The senser element that adopts in the present embodiment is 350 ohm that Japanese Tokyo Sokki Kenkyujo company produces, FLA-2 series foil gauge.Consider that from long-time stability what foil gauge was pasted employing is epoxies, but not alpha-cyanoacrylate salt binding agent.Foil gauge adopts beam mode.Data transmission cable (selecting ordinary telephone line for use) by 4 cores between senser element and the follow-up amplifying circuit is connected, and wherein 2 cores are used for power supply and supply with, and 2 cores are used for signal output.The acp chip of the amplifying circuit that adopts in the present embodiment is RS846-171.Because the output of the signal of strain gauge bridge network often is less than the millivolt level, and the common-mode voltage of its general measure is lying prostrate more than the level at least, can't satisfy the requirement that follow-up data is gathered, and must carry out necessary amplification and common mode inhibition at all.RS846-171 is low noise, low drift, high reliability and linear amplifier chip, adopts the encapsulation of 24 pins, and unidirectional current is supplied with.It can overcome common mode inhibition by the mode of cancellation common-mode voltage, concrete operation principle is to rely on to adjust the size that the Wheatstone bridge power supply is supplied with negative terminal voltage, make that signal is zero in its output negative terminal voltage perseverance, and for a symmetrical electric bridge, equal and opposite in direction, polarity that the power supply of this moment is supplied with positive and negative terminal voltage are opposite, therefore also just obtain the zero common-mode voltage of output signal.Enlarging function as for output signal is to realize by the peripheral circuit of RS846-171.Wherein the signal amplification is actual selects 1000 times for use.The regulated power supply size that adopts in the invention is ± 12V.Consider the convenience of use, regulated power supply adopts external AC220V to change generation.AC220V passes through 12V transformator transformation successively, and diode bridge rectification and three processes of 7812/7912 voltage stabilizing change the amplifying circuit of suitable burning voltage signal feed system into.The analog-digital commutator that adopts in the present embodiment comprises I/O connecting plate (I/O Connector Blocks) and multifunctional data acquisition card (DAQ Card) two parts composition.That the I/O connecting plate adopts is CB-68LPR, and it includes public mouthful of 68 pins, can provide low noise I/O signal output up to specification for DAQ.That multifunctional data acquisition card adopts is NI 6024E, it has 16 tunnel single-ended/8 road difference analogues inputs, 12 precision, the 200KS/s sample rate, 200KS/s disk writing speed, ± 0.05 arrives ± the 10V input range, 12 simulation outputs of two-way at most, maximum 32 digital I/O lines, two-way 24 digit counters/intervalometer can satisfy the actual measurement requirement fully.What in addition, the transfer of data between I/O connecting plate and multifunctional data acquisition card adopted is the PSHR68-68 shielded cable.Data acquisition software is based on that Labview sets up, and wherein data are read in by I/O 1～12 passage, and sampling length and sample frequency can be by the computer adjustment, and invention is actual, and that adopt is 600 and 10Hz.Delivering to the gui data process software by software interface after the data acquisition handles, shows and store, the personal information information of simultaneously relevant user also can utilize the graphic user interface date processing interface of this software to carry out typing, makes things convenient for the foundation and the integration of clinical database.

Main points of the present invention are the FInite Element location of strain gauge bridge; The redundancy of multi-lead signal-optimization process method; The design of machine front cabinet; Date processing interface based on GUI; Sport technique segments such as the static demarcating of system.

The FInite Element location of strain gauge bridge:

In observation process, HRV always has six kinds of unknown quantitys, i.e. each x of every handle of walker, y, three durection component (left hands: F of z _Lx, F _Ly, F _LzThe right hand: F _Rx, F _Ry, F _Rz), require to be recorded by system, therefore need six cover strain gauge bridges respectively be installed standard two-wheeled walker two side frame beams, see Fig. 3.The concrete installation site of electric bridge is to be determined by structural mechanics finite element analysis (FEA) result that the walker framework is carried out.Because the walker framework can produce different deformation effects under the effect of different directions component force, electric bridge all is to be arranged at the relative largest deformation of framework position under the effect of forces associated credit amount to obtain the most reliable result.Wherein, B-1 and B-2, B-7 and B-8 correspond respectively to x to two components, B-3 and B-4, B-5 and B-6 correspond respectively to y to two components, B-9 and B-10, B-11 and B-12 correspond respectively to z to two components.In addition, cause the difference of bending moment direction according to institute's ergometry component, the electric bridge paste position also needs the corresponding deformation side corresponding to the beam pipe.

The redundancy of multi-lead signal-optimization process method:

Among the present invention, the designs of overlapping electric bridges at the single direction power employing two of HRV belong to a kind of redundant measurement.This is wherein superfluous

A surplus cover electric bridge is very important by the non-linear and interactive interference of dynamometry for reducing.Theoretically, the output signal of a cover strain gauge bridge should be linear with corresponding a certain durection component power.But in fact, this linear relationship is unsatisfactory, and can produce big interactive interference between the different component force.In order to address this problem, adopted " redundancy-optimization " method in the design.It is advantageous that: the non-linearization that 1) has farthest alleviated output relation by the method that increases effective information; 2) set up net connection between the output that difference is led, produced an aggregate balancing result, reduced the interactive interference between the durection component power.Particularly, redundant metrical information can effectively be replenished electric bridge output because of various accidentalia in this research, moves the non-linearization that is brought as the centre of effort is little.In addition, this two cover electric bridge (main, the sensitivity weighted value is higher) and other ten overlap electric bridge (reference, the sensitivity weighted value is lower) and can be regarded as an overall network consider in this direction calibration process.After the demarcation, the original sensitivities coefficient matrix [SM] of system will be one 12 * 6 an overdetermination matrix, but not 6 * 6 square formation.Again [SM] carried out transposition and ask [SM] ^-1The time, in fact just optimize solution procedure at overdetermined equation, the network optimization result of all information that has been exactly a balance who finally obtains, this has also significantly reduced the interactive interference between all directions power.

The design of machine front cabinet: for being convenient for measuring and improving the portability of system, the present invention is removing the senser element stick on the walker and being installed in the machine front cabinet attached to all hardware device outside of the data collecting card in the computer, see Fig. 4, the 1st, the phone wire harness, the 2nd, the 220v power line, 3 is 68 needle interfaces, the 4th, and on and off switch, the 5th, power supply indicator.The machine front cabinet only keeps a data input port, a data delivery outlet and a power supply input port.Consider between each strain gauge bridge and its follow-up amplifying circuit to connect, so in fact the data input port of machine front cabinet is made up of 12 telephone line interfaces by telephone wire.Data output is public mouthful of 68 pins of I/O connecting plate, is the PSHR68-68 shielded cable usefulness of plugging into.The power supply input port is a 3-phase plug of reserving an AC220V.In addition, the machine front cabinet also is provided with an on and off switch and a power supply indicator, can be so that practical operation.Thus, whole walker dynamometry hardware system just can be reduced to three main entity components: walker (containing foil gauge), machine front cabinet and computer (containing capture card), the difference of the walker here and general walker just be the framework surface attachment slightly little foil gauge and drawn a little thin cable wherein, from profile and weight, almost do not change, thereby can not have influence on the normal gait of user yet.

Software system:

Software system comprises data acquisition and processing (DAP) two parts composition.As shown in Figure 6, carry out following steps during computer run Labview data acquisition software: acquisition channel is set, and acquisition length is set, and frequency acquisition is set, image data, and text storage and oscillography plate monitor.As shown in Figure 7, carry out following steps during computer run gui data process software: patient's data input, selected pending data file, initialization, HRV calculates, " selected pending data file " step is returned in storage, demonstration, double counting and cleaning input after the double counting, return " patient's data input " step after the cleaning input.

Date processing interface based on GUI:

Consider the convenience that Monitoring Data and clinical data are handled, the present invention designs the date processing interface of having set up based on GUI, sees Fig. 5.Option in the interface has four big classes to be formed, and is respectively:

Text input option: name (Name), the age (Age) is the height (Height) of unit with cm and be the body weight (Weight) of unit with kg.

Menu drop-down option: sex (Sex), option comprises man (Male), woman (Female) in drop-down, acquiescence/display items is man (Male), stimulated side (Side), option comprises both sides (Both), left side (Left), right side (Right), does not have (Nil) in drop-down, and acquiescence/display items is both sides (Both).

Figure ejects option: comprise

Three buttons can show every result of HRV respectively.

General utility functions option: comprise With

Five buttons, these all are and handle the function associated option.First three be respectively open, initialization and storage data program, latter two is respectively double counting and the input of cleaning text.

The static demarcating of system:

In system's static demarcating process, known standard weight progressively is applied on the walker handle along each component direction of HRV, calculates the sensitivity coefficient matrix of system by corresponding output signal.

System sensitivity coefficient matrix and output voltage, the linear relationship that applies the HRV load can be represented by the formula:

[V]=[SM] [F] (1) [V] here is the column vector of representing output voltage, and [F] represents HRV load column vector, and sensitivity coefficient matrix [SM] connects these two.Find out that by (1) formula the sensitivity coefficient matrix of timing signal can be solved by following formula:

[SM]＝[F _lx./V _lx，F _ly./V _ly，...，F _rz./V _rz] (2)

Here F _Lx./V _Lx, F _Ly./V _Ly, F _Lz./V _LzBe respectively left hand x, y, sensitivity coefficient column vector under the effect of z durection component power, F _Rx./V _Rx, F _Ry./V _Ry, F _Rz./V _RzBe right hand x, y, sensitivity coefficient column vector under the effect of z durection component power.Like this, along with determining of [SM], all HRV vectors of making a concerted effort that are applied on the handle just all can be released from following formula:

[F]＝[SM] ^-1[V] (3)

The initialization survey that it is noted that system is very necessary for obtaining of calibration result.Because be subjected to temperature, the influence of external environments such as humidity is not even strain gauge bridge output can be kept a fixed value yet when zero load.Therefore before demarcating, must carry out system initialization, obtain system's output valve of there and then zero load.Carry out in the data handling procedure follow-up, formal measured value will deduct quiescent value to eliminate environmental effect, correctly reflects the variation of HRV in the walking process.

The error checking experiment:

In order to examine or check the present invention, carried out relevant error checking experiment, comprising non-linear, the cross interference and the mechanics accuracy test of system in reliability and feasibility aspect the mechanics monitoring.

Non-linear check: the non-linear check utilization multiaxis framework and the series of standards weight of system are carried out.The HRV folk prescription is applied on the walker handle to component force.X, y and z are respectively 20,20 and 80kg to range ability, the heavy burden of single 5kg progressively increases from 0 to full scale, progressively is decremented to 0 again.Like this between 0 and full scale between, each equivalent test point all can have and loads and two measured values of unloading.Difference between these two is got maximum, and the substitution following formula just can obtain nonlinearity erron:

$E_l=\left|\frac{D_{\max }}{F_{\mathrm{ful}}}\right|\×100\%---\left(4\right)$

Here D _MaxBe the maximum difference of the loading and unloading that measures, F _FullIt is range ability.

What table 1 provided is system's nonlinear error value, and maximum nonlinearity erron appears at F _LxOn the component force direction, be 2.901%, minimum nonlinearity erron appears at F _LyOn the component force direction, be 0.615%.

Cross interference check: in the cross interference checkout procedure of system, when each HRV folk prescription when component force is applied on the walker handle, according to signal of telecommunication output valve that records and calibrated system sensitivity coefficient matrix, on other 5 component directions, can calculate corresponding pseudo-power output.The cross interference error just can be calculated according to following formula:

$C{T}_{i-j}=\left|\frac{F_i}{F_j}\right|\×100\%---\left(5\right)$

Here F _iBe the puppet output of system on the i direction, F _jIt is the test component that is applied on the j direction.

What table 2 provided is the system interaction interference value, and maximum interactive interference appears at and applies F _LzDuring component force to F _RzThe interference of component force is 3.188%, secondly for applying F _RzDuring component force to F _LzThe interference of component force is 3.034%.

The mechanics accuracy test: the check of mechanics of system precision is to rely on the load that applies eight directions respectively to carry out.These eight directions are according to the three axes of Descartes's rectangular coordinate system of having set up whole lab spaces to be divided.The series of standards weight of using previously is used as reference load.Utilization multiaxis framework is loaded into reference load on the walker handle by these eight directions respectively.By calibration equation, the correspondent voltage signal can be converted into the power output F on each handle _x, F _yAnd F _z

The power output amplitude size of any direction can be calculated according to following formula:

$F_r=\sqrt{F_x^2+{\mathrm{<figure-callout\; id="2"\; label="F\; y"\; filenames="A20051001457400121.png"\; state="\{\{state\}\}">F</figure-callout>}}_y^{}{+F}_z^2}---\left(6\right)$

The mechanics trueness error of system can be calculated according to following formula:

$E_f=\left|\frac{F_r-F_{\mathrm{lc}}}{F_{\mathrm{lc}}}\right|\&times;100\%---\left(7\right)$

Here F _LcIt is the reference load that standard weights applies.

Table 3 provides be system from all directions to the mechanics accuracy value, maximum mechanics trueness error appears at left hand (F _x,-F _y,+F _z) in this director space, be 1.01%.

The error checking experimental result shows dynamometry nonlinearity of the present invention less than 2.901%, and interactive interference is less than 3.2%, and degree of accuracy is better than 1.01%, can reach the monitoring requirement of walker walk help kinetic parameter HRV in the research fully.In addition, the present invention has accurately in real time, convenient feasible characteristics, can also when guaranteeing user normal gait device walking training, implement the HRV monitoring function, quantize the walking quality, reduce the walker application risk, and for the biomechanics of walk help dynamics research in the following clinical rehabilitation and walker again design reliable scientific basis is provided.

The walker walk help kinetic parameter monitoring method that the present invention carries under the prerequisite that does not influence the normal walk help process of user, can accurately be differentiated its power demand in real time, quantizes the walking quality, reduces the walker application risk.This invention can be effective instruction of walker and the reliable evaluation of walk help effect is offered help, and obtains considerable social benefit and economic benefit.Optimum implementation intends adopting patent transfer, technological cooperation or product development.

Table 1. nonlinearity erron

	F lx	F ly	F lz	F rx	F ry	F rz
							Range (kg) maximum difference (kg) nonlinearity erron (%)	20 0.5801 2.901	20 0.1231 0.615	80 0.9764 1.221	20 0.5329 2.665	20 0.5763 2.882	80 0.8474 1.059

Table 2. interactive interference

Table 3. is from all directions to the mechanics precision

Add force direction	A left side			Right
							F r(kg)	F lc(kg)	E f(％)	F r(kg)	F lc(kg)	E f(％)
	-F x，-F y，-F z -F x，-F y，+F z +F x，-F y，-F z +F x，-F y，+F z -F x，+F y，-F z -F x，+F y，+F z +F x，+F y，-F z +F x，+F y，+F z	42.0 46.8 40.4 43.1 39.7 44.3 31.1 45.2	41.783 46.332 40.607 42.707 39.784 43.935 31.231 44.868	0.52 1.01 0.51 0.92 0.21 0.83 0.42 0.74	41.8 39.8 40.5 44.6 41.2 45.8 31.2 45.6	41.725 40.048 40.630 44.312 41.003 45.351 31.322 45.220							0.18 0.62 0.32 0.65 0.48 0.99 0.39 0.84

Claims (2)

1, a kind of arrangement for monitoring walk-assisting kinetic parameters of walking device, comprise walker and be arranged on foil gauge on the walker, it is characterized in that described foil gauge is the 12 strain gauge bridge networks that lead, be used for extracting indirectly HRV information, it is arranged on the position beyond the described walker framework upper handle; The described 12 strain gauge bridge networks that lead are connected with amplifying circuit, analog to digital conversion circuit and computer; The described 12 output analogue signals of leading the strain gauge bridge network export analog to digital conversion circuit to after amplifying circuit amplifies, analog to digital conversion circuit is that digital signal exports computer to above-mentioned analog signal conversion.

2, a kind of arrangement for monitoring walk-assisting kinetic parameters of walking device according to claim 1, it is characterized in that, described Computer Storage has Labview data acquisition software and gui data process software, carry out following steps during described computer run Labview data acquisition software: acquisition channel is set, acquisition length is set, frequency acquisition is set, image data, and text storage and oscillography plate monitor; Carry out following steps during described computer run gui data process software: patient's data input, selected pending data file, initialization, HRV calculates, storage, demonstration, double counting and cleaning input, return " selected pending data file " step after the double counting, return " patient's data input " step after the cleaning input.

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