Summary of the invention
The problem that focusing algorithm is complicated, operand is large is caused after adding voussoir in order to solve phased array probe front end in prior art, propose and a kind of there are retardation computing method in the ultrasound examination of voussoir, the retardation of relatively accurate current array element can be obtained with less calculation cost.
Embodiments provide and a kind of there are retardation computing method in the ultrasound examination of voussoir, comprise,
Calculate the prediction incidence point that anticipation focus point is corresponding;
Calculate current array element to described prediction incidence point, described prediction incidence point to summation during the prediction sound of described anticipation focus point;
Mobile described prediction incidence point is formed and moves into exit point, calculate current array element to described in move into exit point, described in move into exit point to summation during the mobile sound of described anticipation focus point;
Minimum value in summation when summation and mobile sound when finding out described prediction sound, as summation during actual sound;
Contrast when summation during described actual sound and center array element are reached the sound envisioning focus point, obtain the retardation that described current array element arrives described anticipation focus point.
A kind of further aspect with retardation computing method in the ultrasound examination of voussoir according to the embodiment of the present invention, non-calculate anticipation prediction incidence point corresponding to focus point first time, using the prediction incidence point of minimum value in summation when summation during previous described prediction sound and mobile sound or move into the prediction incidence point that exit point calculates as this.
A kind of another further aspect with retardation computing method in the ultrasound examination of voussoir according to the embodiment of the present invention, mobile described prediction incidence point formation moves into exit point and comprises, move described prediction incidence point using a predetermined step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
A kind of another further aspect with retardation computing method in the ultrasound examination of voussoir according to the embodiment of the present invention, mobile described prediction incidence point formation moves into exit point and comprises, obtain the vector distance in described prediction incidence point and current array element horizontal direction, value minimum in described vector distance is as step value, move described prediction incidence point using this step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
A kind of another further aspect with retardation computing method in the ultrasound examination of voussoir according to the embodiment of the present invention, calculate current array element to described prediction incidence point or calculate current array element to described in move into exit point time, when the incident angle that described current array element arrives described prediction incidence point or moves into exit point is greater than the angle of total reflection, then described current array element to during the sound of described prediction incidence point and current array element to described in move into the sound of exit point time be, after current array element is set out arrive between voussoir and measured object interface with the angle of total reflection, when arriving described prediction incidence point along the direction being parallel to described interface or move into the sound of exit point.
The embodiment of the present invention additionally provides a kind ofly has retardation calculation element in the ultrasound examination of voussoir, comprises,
Prediction incidence point computing unit, for calculating prediction incidence point corresponding to anticipation focus point;
Sum calculation unit during prediction sound, for calculating current array element to described prediction incidence point, described prediction incidence point to summation during the prediction sound of described anticipation focus point;
Sum calculation unit during mobile sound, is formed for mobile described prediction incidence point and moves into exit point, before calculating array element to described in move into exit point, described in move into exit point to summation during the mobile sound of described anticipation focus point;
Sum calculation unit during actual sound, minimum value in summation when summation and mobile sound during for finding out described prediction sound, as summation during actual sound;
Comparing unit, contrasts when summation during described actual sound and center array element are reached the sound envisioning focus point, obtains the retardation that described current array element arrives described anticipation focus point.
A kind of further aspect with retardation calculation element in the ultrasound examination of voussoir according to the embodiment of the present invention, during described prediction sound, sum calculation unit is further, move described prediction incidence point using a predetermined step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
A kind of another further aspect with retardation calculation element in the ultrasound examination of voussoir according to the embodiment of the present invention, during described prediction sound, sum calculation unit is further, obtain the vector distance in described prediction incidence point and current array element horizontal direction, value minimum in described vector distance is as step value, move described prediction incidence point using this step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
A kind of another further aspect with retardation calculation element in the ultrasound examination of voussoir according to the embodiment of the present invention, when described prediction sound sum calculation unit calculate current array element to sum calculation unit when described prediction incidence point or described mobile sound calculate current array element to described in move into exit point time, when the incident angle that described current array element arrives described prediction incidence point or moves into exit point is greater than the angle of total reflection, then described current array element to during the sound of described prediction incidence point and current array element to described in move into the sound of exit point time be, after current array element is set out arrive between voussoir and measured object interface with the angle of total reflection, when arriving described prediction incidence point along the direction being parallel to described interface or move into the sound of exit point.
By method and the device of the invention described above embodiment, the retardation of mutually more accurate current array element can be obtained with lower calculation cost.
Embodiment
Description below can make any those skilled in the art utilize the present invention.Specific embodiment and the descriptor provided in applying are only example.Various extension and the combination of embodiment as described herein are apparent for those skilled in the art, and when not departing from the spirit and scope of the invention, the rule of the present invention's definition can be applied in other embodiments and application.Therefore, the present invention is not only limited to shown embodiment, and the maximum magnitude consistent with principle shown in this paper and feature is contained in the present invention.
The form that detailed description is below expressed with process flow diagram, logic module and other symbol manipulation provides, and can perform on the computer systems.Program, a computing machine perform step, logical block, process etc., and what be envisioned for one or more step of obtaining desired result or instruction here is in harmony sequence certainly.These steps are the physical operationss to physical quantity.These physical quantitys comprise electricity, magnetic or radio signal, and they are stored in computer systems, which, transmit, combine, compare and other operate.But these signal bit, numerical value, element, symbol, character, condition, numerals etc.Each step can be passed through hardware, software, firmware or their combination and perform.
When phased array supersonic carries out the scanning of various focusing and deflection, all need to look for an original bench mark point, generally with center array element for reference point, so the delay general Ye Yi center array element echoed signal of each array element echoed signal is reference point.Be illustrated in figure 1 embodiment of the present invention phase-array scanning schematic diagram, setting sample frequency is F, the velocity of sound is v, then the sound path of each sampling interval representative is l=v/F, sound path spacing on the sweep trace K set for starting point with center array element A is as the point of l is as the focus point of anticipation is (in figure 1, 2, 3 ... be depicted as anticipation focus point), in order to the echo coherence stack from focus point making each array element (array element B and array element C) receive, the waveform that need receive each array element carries out accurate delay, each array element and center array element are the retardation of each array element to sound time difference of focus point, retardation initial is as can be seen from Figure determined by the distance of each array element and center array element.
Along with the continuity of sweep time, anticipation focus point extends along sweep trace, each array element respective delay amount is also gradually changing simultaneously, according to triangle relation, each array element retardation along with anticipation focus point extension reduce gradually, in each sampling period, the reduced value of retardation is not more than 2 sampled points.
According to Fermat principle, during the propagation of sound wave in two media between 2, along the propagated that required time is the shortest.Be illustrated in figure 2 embodiment of the present invention center array element in voussoir and launch the schematic diagram of sound wave, if sampling rate is F, the thickness of known voussoir is Tw, and the velocity of sound is v
1, the measured object velocity of sound is v
2, with the measured object velocity of sound for benchmark, then the equivalent sound path coefficient of voussoir is
current array element and center array element distance are d, knownly will produce the sweep trace that angle is Ar, and according to the velocity of sound ratio between voussoir and measured object, the sound wave shooting angle that can calculate center array element according to refraction theorem should be Ai.With the retardation of the sound wave sent by center array element 201 for the current array element 202 of benchmark, sound wave arrives voussoir and measured object interface is scanning initial time, and this position is also initial focus point, as a point in Fig. 2.
It is to reflect that sound wave transmits between different medium, and when being transferred in the medium of speed in by slow medium, will be totally reflected when incident angle is greater than certain angle value, this angle is exactly the angle of total reflection, and angle is arcsin (v
1/ v
2).
Be illustrated in figure 3 a kind of process flow diagram with retardation computing method in the ultrasound examination of voussoir of the embodiment of the present invention.
Comprise step 301, calculate the prediction incidence point that anticipation focus point is corresponding.
Step 302, calculates current array element to described prediction incidence point, described prediction incidence point to summation during the prediction sound of described anticipation focus point.
Step 303, mobile described prediction incidence point is formed and moves into exit point, calculate current array element to described in move into exit point, described in move into exit point to summation during the mobile sound of described anticipation focus point.
Step 304, minimum value in summation when summation and mobile sound when finding out described prediction sound, as summation during actual sound.
Step 305, contrasts when summation during described actual sound and center array element are reached the sound envisioning focus point, obtains the retardation that described current array element arrives described anticipation focus point.
Wherein above-mentioned steps 302 and step 303 order are in no particular order.
As one embodiment of the present of invention, in described step 301, non-calculate anticipation prediction incidence point corresponding to focus point first time, using the prediction incidence point of minimum value in summation when summation during previous described prediction sound and mobile sound or move into the prediction incidence point that exit point calculates as this.Such as when the prediction incidence point of calculating second anticipation focus point, using the prediction incidence point of the minimum value representative obtained in first time computing relay amount process steps 304 or move into the prediction incidence point of exit point as the second anticipation focus point.
As one embodiment of the present of invention, in described step 303, mobile described prediction incidence point is formed and moves into exit point and comprise, and moves described prediction incidence point move into exit point as described using a predetermined step value, wherein, moving direction is the direction from center array element to described current array element.
As an embodiment of this law invention, in described step 303, mobile described prediction incidence point formation moves into exit point and comprises, obtain the vector distance in described prediction incidence point and current array element horizontal direction, value minimum in described vector distance is as step value, move described prediction incidence point using this step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
As an embodiment of this law invention, calculate current array element to described prediction incidence point or calculate current array element to described in move into exit point time, when the incident angle that described current array element arrives described prediction incidence point or moves into exit point is greater than the angle of total reflection, then described current array element to during the sound of described prediction incidence point and current array element to described in move into the sound of exit point time be, after current array element is set out arrive between voussoir and measured object interface with the angle of total reflection, when arriving described prediction incidence point along the direction being parallel to described interface or move into the sound of exit point.
By the method for above-described embodiment, the retardation of mutually more accurate current array element can be obtained with lower calculation cost.
Be illustrated in figure 4 a kind of structural drawing with retardation calculation element in the ultrasound examination of voussoir of the embodiment of the present invention.
Comprise prediction incidence point computing unit 401, for calculating prediction incidence point corresponding to anticipation focus point.
Sum calculation unit 402 during prediction sound, for calculating current array element to described prediction incidence point, described prediction incidence point to summation during the prediction sound of described anticipation focus point.
Sum calculation unit 403 during mobile sound, is formed for mobile described prediction incidence point and moves into exit point, before calculating array element to described in move into exit point, described in move into exit point to summation during the mobile sound of described anticipation focus point.
Sum calculation unit 404 during actual sound, minimum value in summation when summation and mobile sound during for finding out described prediction sound, as summation during actual sound.
Comparing unit 405, contrasts when summation during described actual sound and center array element are reached the sound envisioning focus point, obtains the retardation that described current array element arrives described anticipation focus point.
As one embodiment of the present of invention, during described prediction sound, sum calculation unit 402 is further, and move described prediction incidence point using a predetermined step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
As an embodiment of this law invention, during described prediction sound, sum calculation unit 402 is further, obtain the vector distance in described prediction incidence point and current array element horizontal direction, value minimum in described vector distance is as step value, move described prediction incidence point using this step value and move into exit point as described, wherein, moving direction is the direction from center array element to described current array element.
As an embodiment of this law invention, when described prediction sound sum calculation unit 402 calculate current array element to sum calculation unit 403 when described prediction incidence point or described mobile sound calculate current array element to described in move into exit point time, when the incident angle that described current array element arrives described prediction incidence point or moves into exit point is greater than the angle of total reflection, then described current array element to during the sound of described prediction incidence point and current array element to described in move into the sound of exit point time be, after current array element is set out arrive between voussoir and measured object interface with the angle of total reflection, when arriving described prediction incidence point along the direction being parallel to described interface or move into the sound of exit point.
By the device of above-described embodiment, the retardation of mutually more accurate current array element can be obtained with lower calculation cost.
Be illustrated in figure 5 the current array element of the embodiment of the present invention and send the schematic diagram that total reflection does not occur sound wave, Figure 6 shows that the current array element of the embodiment of the present invention sends the schematic diagram that total reflection occurs sound wave, known current array element A and center array element B spacing are d, the sound wave path that current array element arrives initial focus point is easier to calculate, be generally by current array element in voussoir direct projection to the sound wave path of initial focus point a, if incident angle is now greater than the angle of total reflection of voussoir, then sound wave path should be and penetrates by the angle of total reflection by from current array element, the incidence point of current array element A is c in figure 6, the incidence point of center array element B is a, be converted in interface in measured object to be parallel to the path transmission (in Fig. 6 path shown in thick lines) at interface.Record current array element is incided incidence point in measured object and current array element position relationship by voussoir, the component being parallel to interface is set to x, and the component being parallel to interface that incidence point arrives focus point is set to y.The y initial when not occurring entirely to launch is 0.Wherein, Pw is the vector distance between center array element to a point in horizontal direction.
Along with the sampling rate of digital to analog converter according to F is sampled, the time take sampling period as step units, and focus point is also the sweep trace of Ar along angle, with
for stepping extends forward, be illustrated in figure 7 the ultrasound examination sound wave schematic diagram of embodiment of the present invention band voussoir, anticipation focus point 1,2,3,4,5 ...According to refraction theorem, along with the extension forward of focus point, the sound wave path arriving focus point from current array element A is also dull mobile through the position of the incidence point at interface, and moving direction is identical to the direction of current array element with center array element B.Incidence point c as shown in the figure
1, c
2, c
3, c
4, c
5The x value x of a corresponding vector respectively
1, x
2, x
3, x
4, x
5
Set the step value of an x according to precision and focusing range, such as select x
1, x
2, x
3, x
4, x
5in minimum pitch value be step value, when each sampling period obtains new focus point, calculate the constant and x of x value according to triangle relation and change two sound paths in a step value two kinds of situations, compare this two acoustical paths required times, sound path during less sound is closer to actual sound path.Thus only needing simple multiplier, totalizer and comparer, the refraction sound path that can complete satisfied certain precision calculates.
As an embodiment, be illustrated in figure 8 the specific embodiment schematic diagram that the present invention calculates sound path, in the figure for anticipation focus point 4, suppose to be extrapolated by comparative approach that to envision the acoustic path of focus point from current array element A to this be c at the prediction incidence point of interface
4, during existing reckoning anticipation focus point 5, first suppose that incidence point is constant, calculate now from current array element to prediction incidence point c
4sound path needed for sound time, add from prediction incidence point c
4to anticipation focus point 5 sound path needed for sound time, S when drawing total sound
0, then suppose that incidence point moves a step value X
step, arrive and move into exit point c
5, calculate from current array element to moving into exit point c
5sound path needed for sound time, add from moving into exit point c
5to anticipation focus point 5 sound path needed for sound time, S when drawing total sound
1, S when comparing two sound
0and S
1, less acoustic path closer to actual acoustic path, thus is predicting incidence point c
4with move into exit point c
5between select closer to actual incidence point a bit.
As a specific embodiment, envision focus point 1,2,3,4,5 through corresponding to of theory calculate in the figure 7 ... prediction incidence point be respectively c
1, c
2, c
3, c
4, c
5, the vector distance x value in described prediction incidence point and current array element A horizontal direction is x
1, x
2, x
3, x
4, x
5For example, x is supposed
1, x
2, x
3, x
4, x
5be respectively 1.5,0.6 ,-0.1 ,-0.7 ,-1.5 ,-1.8 ,-2.1 ,-2.4 ,-2.7 ,-2.8 ... stepping can be selected to be 0.6, then the vector distance moving into exit point and described current array element A horizontal direction after moving is respectively 1.5,0.9,0.3 ,-0.3 ,-0.9 ,-1.5 ,-2.1 ,-2.1 ,-2.7 ,-2.7 ...Utilize mobile after vector distance calculate from current array element A arrive move into exit point after add and move into summation when exit point arrives the mobile sound of anticipation focus point, calculate summation when arriving the prediction sound of adding prediction incidence point arrival anticipation focus point after prediction incidence point from current array element A, summation when summation and prediction sound during more described mobile sound, using during minimum sound as summation during actual sound, when supposing mobile sound, minimum (during prediction sound, summation also may be minimum for summation, can analogize), then from current array element arrive move into exit point after add move into when exit point arrives the sound of anticipation focus point be actual sound time, utilize this actual Sheng Shiyu center array element set out arrive anticipation focus point sound time compare, obtain current array element and arrive the time envisioned focus point and should postpone, namely current array element arrives the retardation of this anticipation focus point.
With the direction of the anticipation focus point shown in scheming, the prediction incidence point envisioning focus point corresponding when just starting moves comparatively fast, so calculate that the exit point position deviation that moves into out can be larger, but along with the extension of anticipation focus point, the position of prediction incidence point is moved more and more less, so calculate out to move into exit point also more and more accurate, error is no more than step value.The accuracy that incidence point calculates can be ensured like this, accurately can draw out the acoustic path that current array element arrives anticipation focus point, when accurately calculating the sound of whole acoustic path, contrast when Zai Yu center array element reaches the sound of anticipation focus point, the retardation of current array element can be obtained.
The present invention can realize in any suitable form, comprises hardware, software, firmware or their combination in any.The present invention can according to circumstances selectively partly realize, and such as software performing is in one or more data processor and digital signal processor.Element and the assembly of each embodiment herein can realize physically, functionally, in logic in any suitable manner.In fact, a function can the part in separate unit, in one group of unit or as other functional units realize.Therefore, this system and method both can realize in separate unit, also can be distributed between different unit and processor physically and functionally.
Technician in the related art will recognize that, embodiments of the invention have many possible amendments and combination, although form is slightly different, still adopts identical fundamental mechanism and method.In order to the object explained, aforementioned description with reference to several specific embodiment.But above-mentioned illustrative discussion is not intended to exhaustive or limits the precise forms of inventing herein.Above, many modifications and variations are possible.Selected and described embodiment, in order to explain principle of the present invention and practical application thereof, in order to the amendment for application-specific, the distortion that enable those skilled in the art utilize the present invention and each embodiment best.