Summary of the invention
Technical problem to be solved by this invention is: provide a kind of energy in real time, the method and system of two stressed distributions of beaer of quantitative measurement and beaer spacing.
Another technical problem to be solved by this invention is: this measuring system can also directly be adjusted the spacing of beaer according to measurement result.
The present invention solves the problems of the technologies described above the technical scheme that is adopted to be:
A kind of system of measuring pressure distribution between two force bodies and spacing size comprises:
One measures fore device, and described measurement fore device is arranged between the described two force bodies, is used to gather pressure signal and spacing variable signal between described beaer;
One measures control and signal processing unit, described measurement control and signal processing unit are used to control the collection of described pressure signal and distance signal, and the described pressure signal that will collect and distance signal carry out date processing, and the measurement result data are shown intuitively.
The measurement fore device of described system comprises: the upper and lower end panel that contacts with described beaer, and several force transducers that are used to gather described pressure signal are fixedly mounted on the upper end surface of described upper end plate; Between the described upper and lower side panel adjustable supporting device is arranged, described adjustable supporting device is used to support described upper and lower side panel, make and keep a determining deviation therebetween, is used to regulate the spacing between the described upper and lower side panel simultaneously; One gap measuring device that is used to gather distance signal between the described upper and lower side panel also is set between the described upper and lower side panel.
The measurement fore device of described system, wherein: described gap measuring device comprises an angular transducer that is fixed on described lower end board upper surface, and the gangbar that is vertically fixed on described upper end plate lower surface; The measurement column of described angular transducer and described gangbar intersect vertically, and closely contact each other, and the measurement column that can drive described angular transducer when described gangbar when its axis moves up and down rotates.
The measurement fore device of described system, wherein: described adjustable supporting device comprises:
Be vertically set on a screw rod at middle part, described lower end board upper surface, the bottom of described screw rod and lower end board upper surface are slidingly matched; One swivel nut, described swivel nut is fixed on the middle part of described upper end plate lower surface; The upper end of described screw rod and described swivel nut are spirally connected;
One governor motion, described governor motion makes upper end plate produce upper and lower displacement by promoting described screw rod rotation.
The measurement fore device of described system, wherein: described force transducer is at least 4, and is evenly distributed on the upper end surface of described upper end plate.
Described system, wherein first kind of scheme is: described measurement control and signal processing unit comprise:
First measure-controlling unit; Described first measure-controlling unit is used to control the collection of described pressure signal and distance signal, and the described pressure signal that will collect and distance signal carry out date processing;
One display terminal that is connected with described first measure-controlling unit; Described display terminal is used to show the measurement result data.
In first kind of scheme of described system: described first measure-controlling unit comprises:
A multi-channel analog switch circuit corresponding and a signal amplification circuit with described pressure transducer quantity; The input of described multi-channel analog switch circuit is connected in series with described pressure transducer outfan respectively, and is connected to described signal amplification circuit input after the parallel connection of multi-channel analog switch circuit outfan;
One control chip single-chip microcomputer is used to control the conducting of described multi-channel analog switch circuit, gathers the signal of described pressure transducer; Simultaneously the described pressure signal of described signal amplification circuit output and the described distance signal of described angular transducer output are carried out the A/D conversion, and output to described display terminal after will carrying out date processing through the digital measurement signal of A/D conversion;
The one input command device that is connected with described control chip single-chip microcomputer, and the memory element that is used to preserve data;
Described display terminal adopts LCDs.
Described system, wherein second kind of scheme is: described measurement control and signal processing unit comprise:
One is used to control the collection of described pressure signal and distance signal, and described pressure signal and distance signal is converted to second measure-controlling unit of digital measurement signal;
A computer that is connected with described second measure-controlling unit; Described computer is by carrying out order exchange and data transmission between data-interface and described second measure-controlling unit, and described digital measurement signal is carried out date processing, and the measurement result data are shown intuitively.
In second kind of scheme of described system, wherein: described second measure-controlling unit comprises:
A multi-channel analog switch circuit corresponding and a signal amplification circuit with described pressure transducer quantity; The input of described multi-channel analog switch circuit is connected in series with described pressure transducer outfan respectively, and connects described signal amplification circuit outfan after the parallel connection of multi-channel analog switch circuit outfan;
The second control chip single-chip microcomputer is used to control the conducting of described multi-channel analog switch circuit, gathers the signal of described pressure transducer; Simultaneously the described pressure signal of described signal amplification circuit output and the described distance signal of described angular transducer output are carried out the A/D conversion, and will export to described computer through the digital measurement signal of A/D conversion.
A kind of method of measuring pressure distribution between two force bodies and spacing size may further comprise the steps:
A, will measure fore device and be placed between the tested two force bodies; Set the clearance D that goes out to begin between described upper end plate and the lower end board
0
B, pressure transducer and angular transducer are calibrated, obtained first fitting a straight line coefficient of described pressure transducer and the second fitting a straight line coefficient of described angular transducer respectively;
C, according to the beginning measuring command, the pressure signal of described a plurality of pressure transducers and the distance signal of described angular transducer are gathered in the first/the second measure-controlling unit control, and convert described pressure signal and described distance signal to the digital measurement signal;
D, described computer/second measure-controlling unit are according to the described first fitting a straight line coefficient and the second fitting a straight line coefficient, described digital measurement signal is calculated and handles, obtain the result data of size of actual pressure between tested two force bodies and spacing, and the mode of described result data with figure or data shown.
Described method, wherein: described method also comprises step e: according to the result data of described step D gained, adjust the adjusting device of described measurement fore device, make described upper end plate produce upper and lower displacement, realize the adjustment to described upper and lower end face distance between plates.
Beneficial effect of the present invention is: adopted said method and system, 1, just can change and carry out in real time, quantitatively, accurately measure the pressure distribution between the two force bodies and spacing, and with measurement result with spatial figure and data intuitively, show exactly; 2, can realize that the limit adjusts the spacing between two force bodies, the instant measurement in limit obtained pressure distribution and spacing data, made things convenient for user to adjust the spacing of upper and lower plates repeatedly according to measurement result, satisfies certain equilibrated needs; 3, adjusting and measuring in the process of spacing, the hands of user need not touch tested beaer all the time, and this is extremely important for the application of doctor in operation process; Therefore, this system and method has satisfied the application demand in modern industry and the modern medical service technical field, and especially the operation of regulating soft tissue balance repeatedly for the doctor in full knee replacement operation process provides a kind of convenience, practical measuring system and method.And this system all adopts the components and parts of low-power consumption, has reduced the security threat of electrical equipment to patient, has more safe, simple, directly perceived and practical advantage in actual applications.
The specific embodiment
With embodiment the present invention is described in further detail with reference to the accompanying drawings below:
The ultimate principle of measuring the pressure size between two force bodies with force transducer is shown in Fig. 1 a and Fig. 1 b, on a stiffener plate, fix a plurality of miniature single-point force transducers, each force transducer is in the pressure limit that can bear, the voltage signal of pick off output and the pressure that is carried on the pick off are linear, that is:
F=aV+b (formula 1)
Wherein V is the voltage swing of pick off output, and f is the size of power, and a is the slope of linear equation, and b is an intercept.Therefore after by the voltage signal V that measures force transducer, just can calculate the size of actual loaded power f on pick off according to formula 1.
The ultimate principle of measuring the two force bodies gap length is shown in Fig. 2 a and Fig. 2 b: the distance D between beaer 1 and beaer 2 smaller (<30mm), and variable quantity also very little (<15mm) time, can adopt high-precision miniature angular transducer 3 to come the variation of inverse displacement.At this moment, angular transducer is converted into angle to the straight-line displacement of beaer spacing variation to be changed, and the angle variable quantity of the air line distance of beaer spacing and angular transducer output satisfies following linear relationship:
D=D
0+ k Δ θ (formula 2)
Wherein D is a distance size between two force bodies, D
0Be an initial value, Δ θ is an angle variable quantity, and k is a proportionality coefficient.By formula 2 as seen, the size of coming computed range D of the signal delta θ by the pick off output of taking measurement of an angle.
The present invention utilizes above-mentioned measuring principle, measures the size and the spacing of pressure between the two force bodies.A kind of system of measuring tension distribution and beaer spacing on the beaer of the present invention comprises: be arranged on one between the two force bodies and measure fore device, described measurement fore device is used to gather pressure signal and distance signal between described beaer; One measures control and signal processing unit, described measurement control and signal processing unit are used to control the collection of described pressure signal and distance signal, and pressure signal and the distance signal that collects carried out date processing, and the measurement result data are shown intuitively.
The structure that is arranged on the measurement fore device between the two force bodies as shown in Figure 3, Figure 4, comprise the upper end plate 1, the lower end board 2 that contact with described beaer, several pressure transducers 3 that are used to gather described pressure signal are fixedly mounted on the upper end surface of described upper end plate 1; Between the described upper and lower side panel adjustable supporting device is arranged, be used for supporting described upper and lower side panel, make maintenance one determining deviation between the upper and lower side panel, be used to regulate the spacing between the upper and lower side panel simultaneously; One gap measuring device that is used to gather distance signal between the described upper and lower side panel also is being set between the upper and lower side panel.In specific implementation, gap measuring device comprises: be fixed on an angular transducer 4 of lower end board upper surface, and the gangbar 5 that is vertically fixed on described upper end plate lower surface; The measurement column and the described gangbar 5 of described angular transducer 4 front ends intersect vertically, and closely contact each other, when upper end plate 1 moves up and down, the gangbar 5 that is fixed on upper end plate 1 just moves up and down along the axis direction of gangbar thereupon, owing to closely contact between gangbar 5 and the measurement column, the measurement column rotation that gangbar 5 moves up and down and just drives angular transducer 4 has promptly produced angle variable quantity Δ θ.Just can go out the displacement of upper end plate according to formula 2, thereby obtain the spacing between the upper and lower side panel by Δ θ inverse.Adjustable supporting device specifically comprises: is vertically set on a screw rod 6 at lower end board upper surface middle part and is fixed on the swivel nut 7 at middle part, upper end plate lower surface, and a governor motion 8; The upper surface of the bottom of screw rod 6 and lower end board 2 is slidingly matched, and the upper end of screw rod 6 and swivel nut 7 threaded, and governor motion acts on screw rod 6, is used for lead-screw 6 rotations; Like this, screw rod 6 perpendicular to the upper and lower side panel has played the effect of supporting the upper and lower side panel on the one hand, on the other hand, when external force is ordered about 6 rotations of governor motion lead-screw, by the rotation of screw rod in swivel nut, make upper end plate 1 relative lower end board 2 produce upper and lower displacement, promptly the distance between the upper and lower side panel changes, and has reached the purpose of regulating spacing between the upper and lower side panel.Governor motion 8 can adopt multiple version to realize, for example drives first bevel gear 83 with handwheel 81, turning cylinder 82 and rotates, and first bevel gear 83 just constitutes a kind of governor motion with second bevel gear, 84 interlocks that are fixed on the screw rod outside; Known by the insider in a word, therefore do not repeated them here.For energy measurement goes out the distribution situation of power on the beaer, the force transducer 3 that is arranged on the upper end plate is at least 4, and is evenly distributed on the upper end surface of upper end plate.
Can there be two kinds of implementations in system of the present invention in specific implementation: a kind of employing autonomous system; A kind of is separation system; Autonomous system adopts identical measurement fore device 10 with separation system, and different is the difference to some extent that is provided with of measuring control and signal processing unit.Below autonomous system and separation system are narrated respectively.
As shown in Figure 4, autonomous system comprises: be used to the power module and the electric quantity of power supply monitoring modular of each several part circuit supply, and a clock circuit (crystal oscillator); Above-mentioned measurement fore device 11; Be used to control the collection of described pressure signal and distance signal, and the described pressure signal that will collect and distance signal carry out first measure-controlling unit of date processing; And one be used for display terminal that the measurement result data show is come out.First measure-controlling unit comprises as the lower part: a multi-channel analog switch circuit corresponding and a signal amplification circuit with force transducer quantity, and for example, force transducer has 4, and analog switching circuit just is 4 the tunnel; Force transducer has 6, and analog switching circuit just is 6 the tunnel; As shown in Figure 5, the input of multi-channel analog switch circuit is connected in series with the force transducer outfan respectively, and is connected to the signal amplification circuit input after the parallel connection of multi-channel analog switch circuit outfan, and signal amplification circuit can adopt the adjustable gain differential amplifier circuit; One control chip single-chip microcomputer, be used to export control signal, control a certain way switch conducting of described multi-channel analog switch circuit, gather the signal of counter stress pick off, thereby by to analog switch open/close selection, finish signals collecting and amplification to all force transducers; Simultaneously, the control chip single-chip microcomputer divides two-way to carry out A/D (sampling) conversion to the pressure signal of described signal amplification circuit output and the distance signal of angular transducer output, to carry out date processing and calculating through the digital measurement signal of A/D conversion again, and finally obtain outputing to described display terminal after actual pressure and the spacing data and carry out data show.First measure-controlling unit also comprises an instruction inputting device that is connected with the control chip single-chip microcomputer, and preserves memory of data.In actual applications, display terminal adopts LCDs (LCD).Native system structurally can be divided into three parts as shown in Figure 6: first is installed in during measurement between the tested two force bodies for measuring fore device 10; Second portion is a control box 20, has comprised first measure-controlling unit, instruction inputting device, power module, electric quantity of power supply monitoring modular in the control box, crystal oscillator and memorizer; That is, all electrical appliance parts except that force transducer and angular transducer and display terminal have been comprised; Third part is video data terminal 30.Measure between fore device 10 and the control box and be connected by power supply/holding wire 40, pick off is under the driving power power supply that control box 20 provides, the signal of output reflection pressure size and distance size, signal is transferred in the control box 20 by power supply/holding wire 40, control box 20 is finished the collection of signal, and sends liquid crystal display terminal 30 to by data wire 50 and finish corresponding data show.
As shown in Figure 7, separation system comprises: with the identical measurement fore device of autonomous system; Be used for the collection of control pressure signal and distance signal, and described pressure signal and distance signal converted to second measure-controlling unit of digital measurement signal; An and computer that is connected with second measure-controlling unit.Second measure-controlling unit comprises crystal oscillator, multi-channel analog switch circuit and a signal amplification circuit equally, and the second control chip single-chip microcomputer; The second control chip single-chip microcomputer is used to export control signal, controls a certain way switch conducting of described multi-channel analog switch circuit, gathers the signal of counter stress pick off; Simultaneously pressure signal and the distance signal that collects carried out the A/D conversion, and will export to described computer through the digital measurement signal of A/D conversion.Described computer is by carrying out order exchange and data transmission between the data-interface and second measure-controlling unit, and digital measuring-signal is carried out date processing and calculating, and the measurement result data are shown intuitively.This shows that separation system is all to put in order with the instruction inputting device in first measure-controlling unit of autonomous system, memorizer and to the function that digital measuring-signal carries out date processing and calculating to realize and finish in computer; Because computer has powerful storage and data processing function, the result data of pressure distribution between the two force bodies that measures and spacing can be shown with the 3 D stereo locate mode, data presented and figure are more directly perceived, in the time of video data, the force value of each force transducer is presented at the position that pressure transducer is arranged, the 3 D stereo display effect adds the mode that numerical value shows, can give the judgement of doctor's visual rationing, the prompting and the help of visual rationing are provided for next step adjustment operation of doctor.Native system structurally is divided into three parts equally, and as shown in Figure 8, first is still measures fore device 10; Second portion still is a control box 21, has comprised second measure-controlling unit, power module and electric quantity of power supply monitoring modular in the control box 21; Third part is computer 60; Computer 60 is connected by the interior serial ports of data wire 51 and control box, send measuring command to the second control chip single-chip microcomputer, and the second control chip single-chip microcomputer in the control box sends the digital measurement signal by data wire 51 to computer.
Utilize above-mentioned autonomous system or separation system can measure pressure distribution and spacing size between the two force bodies, as shown in the figure, its measuring method step is:
A, above-mentioned measurement fore device is placed between the tested two force bodies; The upper and lower end panel of measuring fore device contacts with described two force bodies respectively, and sets the clearance D that goes out to begin between described upper end plate and the lower end board
0
B, each force transducer and angular transducer are calibrated, obtained the fitting a straight line coefficient of pressure transducer and the fitting a straight line coefficient of described angular transducer respectively;
C, computer send measuring command (separation system) to the second control chip single-chip microcomputer, or input equipment to first monolithic send the measuring command machine according to the beginning measuring command (autonomous system), the second control chip single-chip microcomputer or the first control chip Single-chip Controlling are gathered the pressure signal of a plurality of force transducers and the distance signal of angular transducer; After collection is finished, convert pressure signal and distance signal to the digital measurement signal;
D, computer (separation system) or first measure-controlling unit (autonomous system) are according to the fitting a straight line coefficient of pressure transducer and the fitting a straight line coefficient of angular transducer, described digital measurement signal is calculated and handles, obtain the result data of size of actual pressure between tested two force bodies and spacing, and the mode of described result data with figure or data shown.
E, according to step D result displayed data, the operator adjusts the adjusting device of measuring fore device, makes described upper end plate produce upper and lower displacement, realizes the adjustment to described upper and lower end face distance between plates.
The calibration of force transducer is by pre-loaded power size and the relation between the force sensor signals amplitude, adopts the linear least square match usually, obtains the fitting a straight line coefficient of each force transducer.The concrete grammar of single force transducer calibration is referring to Figure 10, for:
(1) setting the load initial value, generally is minima, sets load recruitment size, minima and maximum;
(2) gaging pressure signal of sensor, and preserve the correspondence position of corresponding signal amplitude in the array;
(3) increase load;
(4) gaging pressure signal of sensor, and preserve the correspondence position of corresponding signal amplitude in the array;
(5) judge whether load is increased to maximum, is, then arrives (6), not, then repeat (3) and (4);
(6) reduce load;
(7) gaging pressure signal of sensor, and preserve the correspondence position of corresponding signal amplitude in the array;
(8) judge whether load reduces to minima, is, then forwards (9) to, not, then repeat (6) and (7);
(9), rise and the linear fit of two groups of data of descent direction, and preserve the linear fit data according to the amplitude size and the corresponding pressure of the pressure transducer of measuring.
Other pressure transducer can be finished separately calibration process according to above-mentioned (1)-(9) step.
The calibration of angular transducer also is by the relation between the signal magnitude of spacing size that sets in advance and angular transducer output, adopts the linear least square match, obtains the fitting a straight line coefficient of angular transducer; Concrete grammar is referring to Figure 11, for:
(1) setting the spacing initial value, generally is minima, sets spacing recruitment size, minima and maximum;
(2) signal of sensor that takes measurement of an angle, and preserve the correspondence position of corresponding signal amplitude in the array;
(3) increase spacing;
(4) signal of sensor that takes measurement of an angle, and preserve the correspondence position of corresponding signal amplitude in the array;
(5) whether judging distance is increased to maximum, is, then arrives (6), not, then repeats (3) and (4);
(6) reduce spacing;
(7) signal of sensor that takes measurement of an angle, and preserve the correspondence position of corresponding signal amplitude in the array;
(8) judge whether spacing reduces to minima, is, then forwards (9) to, not, then repeat (6) and (7);
(9), rise and the linear fit of two groups of data of descent direction, and preserve the linear fit data according to the amplitude size and the corresponding spacing of the angular transducer of measuring.
The calibration of above-mentioned force transducer and angular transducer is all by the software automatic setting in the measuring system.
System of the present invention and measurement method of adjustment can be used in total knee replacement operation or the artificial limb making, measurement fore device with high accuracy, high-resolution and high sensor is seated between tibia and the femur, just can quantitatively, accurately measures the spacing of pressure distribution between tibia and the femur and shin, femur; The prompting of doctor's graph data intuitively that can also demonstrate in real time according to display terminal is simultaneously directly adjusted the spacing of upper and lower side panel by the adjusting device of measuring fore device, finishes the accurate adjusting of soft tissue balance in the knee joint; And help the doctor to select the artificial knee joint of suitable size for sick body.Simultaneously native system is owing to adopt the low tension battery power supply, and this system all adopts the components and parts of low-power consumption, reduced the security threat of electrical equipment to patient, has more safe, simple, directly perceived and practical advantage in actual applications.
Be understandable that, for those of ordinary skills, can be equal to replacement or change according to technical scheme of the present invention and inventive concept thereof, and all these changes or replacement all should belong to the protection domain of the appended claim of the present invention.