JP2005342194A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ultrasonic diagnostic apparatus where a circuit scale is reduced without markedly deteriorating transmission energy and transmission directional characteristic in a two-dimensional array ultrasonic probe. <P>SOLUTION: Two-dimensionally arrayed ultrasonic vibration elements provided in the ultrasonic probe 20 are divided into a prescribed size to form a plurality of sub arrays, and an internal sub array element connection part 31 in an element selection part 30 connects the ultrasonic vibration elements existing at a nearly equal distance from the transmission converging point of transmission ultrasonic waves in common in a prescribed direction in each sub array. Next, an inter-sub array element connection part 32 additionally connects ultrasonic vibration elements connected in common within a prescribed sub array with those connected in common in a sub array adjacent to the sub array based on a distance to the transmission converging point of the transmission ultrasonic waves to form a group of the ultrasonic vibration elements having the number of channels nearly equal to the number of the driving channels of a transmission part 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus that performs ultrasonic transmission / reception using two-dimensionally arranged ultrasonic vibration elements.

  The ultrasonic diagnostic apparatus radiates an ultrasonic wave generated from an ultrasonic transducer built in an ultrasonic probe into a subject and receives a reflected wave caused by a difference in acoustic impedance of the subject tissue by the ultrasonic transducer. Is displayed on the monitor. This diagnosis method is widely used for organ function diagnosis and morphological diagnosis because real-time two-dimensional image data can be easily obtained by a simple operation by simply bringing an ultrasonic probe into contact with the body surface.

  Ultrasound diagnostic methods for obtaining biological information from reflected waves from the tissue or blood cells of a subject have made rapid progress with the development of two major technologies, the ultrasonic pulse reflection method and the ultrasonic Doppler method, and are obtained using the above technology. The B-mode image and the color Doppler image that are obtained are indispensable in today's ultrasound diagnosis.

  In the most popular electronic scanning ultrasonic diagnostic apparatus today, a plurality of ultrasonic vibration elements are generally arranged one-dimensionally, and the driving of each of these ultrasonic vibration elements is controlled at high speed. Real-time display of image data.

  In this case, the above-described two-dimensional image data is generated by two-dimensional scanning performed on the subject. In recent years, three-dimensional image data (volume data) obtained by performing three-dimensional scanning is used. Based on this, ultrasonic diagnostic methods using three-dimensional image data such as two-dimensional image data (MPR image data) of arbitrary cross sections and volume rendering image data are becoming widespread.

As a method of collecting the three-dimensional image data, a method of further mechanically moving or rotating a conventional ultrasonic probe in which ultrasonic vibration elements are arranged one-dimensionally (see, for example, Patent Document 1), and two-dimensional. There has been proposed a method for sequentially transmitting and receiving ultrasonic waves in a plurality of directions in a three-dimensional space using arranged ultrasonic transducers. (For example, refer to Patent Document 2).
Japanese Patent Laid-Open No. 5-228145 (pages 3-6, FIGS. 1-6) US Pat. No. 5,563,346 (pages 5-9, FIGS. 1-6)

  According to the method of Patent Document 1, it is possible to collect three-dimensional image data with a relatively simple device configuration. However, since collection of the three-dimensional image data requires a lot of time, real-time display is impossible. Therefore, it is extremely difficult to accurately obtain information such as fast-moving organs and blood flow.

  On the other hand, as a method of using two-dimensionally arranged ultrasonic vibration elements, a drive signal supplied to each of the ultrasonic vibration elements and a delay time control of a reception signal obtained from these ultrasonic vibration elements can be used for any arbitrary three-dimensional space. For example, in a predetermined direction (X direction), ultrasonic scanning is performed by the above-described delay time control, and in a direction perpendicular to the predetermined direction (Y direction). There is a method of performing ultrasonic scanning by electronic aperture movement (movement of an ultrasonic vibration element group used for transmitting and receiving waves).

  However, in any case, as the number of ultrasonic vibration elements increases (for example, 10 to 100 times), a transmission / reception circuit that performs transmission / reception with respect to the ultrasonic vibration element, the transmission / reception circuit, and the ultrasonic wave The number of cable channels connecting the vibration elements also increases. That is, the ultrasonic probe and the transmission / reception circuit are extremely complicated and increase in size and weight, so that the operability is significantly lowered.

  With respect to such a problem, in Patent Document 2 described above, a changeover switch is provided in the vicinity of the two-dimensionally arranged ultrasonic vibration elements, and the ultrasonic vibration elements in a predetermined direction are simultaneously transmitted from the ultrasonic vibration elements. There has been proposed a method of selecting an ultrasonic vibration element to be driven by the changeover switch. According to this method, the number of channels of cables and transmission / reception circuits can be reduced by providing the changeover switch in the ultrasonic probe.

  However, according to the above-described method, it is necessary to mount an extremely large number of changeover switches in an ultrasonic probe having a limited space, and severe restrictions are imposed on the mounting area and power consumption (heat generation) of each switching circuit. Is imposed. For this reason, it becomes difficult to supply a sufficient drive voltage to the ultrasonic vibration element, which causes S / N deterioration in image data.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to collect images when ultrasonic image data is collected using an ultrasonic probe having a two-dimensional array of ultrasonic vibration elements. An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of reducing the scale of the apparatus without deteriorating the image quality of data.

  In order to solve the above-described problem, an ultrasonic diagnostic apparatus according to the first aspect of the present invention includes an ultrasonic probe including two-dimensionally arranged ultrasonic vibration elements and a predetermined two-dimensional array of ultrasonic vibration elements. First element connecting means for commonly connecting a part of the plurality of ultrasonic vibration elements in each of the plurality of sub-arrays divided into sizes of the first sub-array, and the first element for each of the plurality of sub-arrays Drive signal for the second element connecting means for further commonly connecting a part of the connecting means, and the ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means And a transmission means for transmitting an ultrasonic wave in a predetermined direction of the subject and a reception signal obtained by the ultrasonic vibration element of the two-dimensional array are phased and added to be substantially the same as the predetermined direction of the subject. Receive ultrasound from the direction of A receiving unit; an image data generating unit configured to generate image data based on a reception signal obtained by the receiving unit while changing a transmission direction and a receiving direction of an ultrasonic wave with respect to the subject; and the generated image data is displayed. And the first element connecting means and the second element connecting means commonly connect ultrasonic vibration elements that are substantially equidistant with respect to the convergence point of the transmission ultrasonic wave. .

  According to a second aspect of the present invention, there is provided an ultrasonic diagnostic apparatus according to the present invention, wherein an ultrasonic probe having a two-dimensional array of ultrasonic vibration elements and the two-dimensional array of ultrasonic vibration elements are divided into predetermined sizes. A first element connecting means for commonly connecting a part of the plurality of ultrasonic vibration elements in each of the plurality of sub-arrays, and one of the first element connecting means for each of the plurality of sub-arrays. A drive signal to a second element connecting means for further commonly connecting the parts, and a transmitting ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means. And receiving means obtained by a transmitting means for transmitting ultrasonic waves in a predetermined direction of the subject and a receiving ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means. Phasing and adding the signals Receiving means for receiving ultrasonic waves from substantially the same direction as the predetermined direction of the body, and image data based on the received signals obtained by the receiving means while changing the transmitting direction and receiving direction of the ultrasonic waves to the subject Image data generating means for generating the image data and display means for displaying the generated image data, wherein the first element connecting means and the second element connecting means are the convergence point of the transmission ultrasonic wave or the reception ultrasonic wave. It is characterized in that ultrasonic vibration elements that are substantially equidistant to at least one of the convergence points are connected in common.

  According to the present invention, when collecting ultrasonic image data using an ultrasonic probe having a two-dimensional array of ultrasonic vibration elements, the apparatus scale can be reduced without degrading the image quality of the image data. Become.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the embodiments of the present invention described below, a plurality of two-dimensionally arrayed ultrasonic vibration elements are divided into predetermined sizes to form a plurality of subarrays, and in each subarray, ultrasonic vibration elements in a predetermined direction are arranged in the first direction. The first ultrasonic vibration element group is formed by common connection by one element connection means (element connection means in the subarray). Next, the first ultrasonic transducer group formed in each of the adjacent subarrays is connected by the second element connection means (inter-subarray element connection means), and the second ultrasonic transducer group that performs simultaneous driving is connected. Form.

(Device configuration)
Hereinafter, the configuration of the ultrasonic diagnostic apparatus and the operation of each unit in the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the ultrasonic diagnostic apparatus according to the present embodiment, and FIGS. FIG.

  An ultrasonic diagnostic apparatus 100 shown in FIG. 1 includes an ultrasonic probe 20 that includes two-dimensionally arranged ultrasonic vibration elements and transmits / receives ultrasonic waves to / from a subject, and the two-dimensional array of the ultrasonic probe 20. The ultrasonic vibration elements that are simultaneously driven are selected from the ultrasonic vibration elements and are connected in common, and a first phasing addition (predetermined) is applied to the reception signals obtained from the two-dimensionally arranged ultrasonic vibration elements. The element selection unit 30 for performing phase addition on the received signals obtained from the direction of (1) and supplying the drive signal to the ultrasonic vibration element group commonly connected in the element selection unit 30 and the first The transmission / reception unit 10 performs a second phasing addition on the reception signal subjected to the phasing addition, and further performs signal processing on the reception signal obtained from the transmission / reception unit 10 so that the B-mode data and the color doppling are performed. A data generation unit 50 that generates data and the like, and the data generated by the data generation unit 50 is stored to generate two-dimensional or three-dimensional B-mode image data and color Doppler image data. A data storage / processing unit 70 for performing desired image processing on the image data and a display unit 81 for displaying the generated image data are provided.

  In addition, the ultrasonic diagnostic apparatus 100 includes a reference signal generator 1 that generates a continuous wave or a rectangular wave having a frequency substantially equal to the center frequency of the transmission ultrasonic wave to the transmission / reception unit 10 or the data generation unit 50, and an operator. An input unit 83 for inputting specimen information, initial setting conditions of the apparatus, various command signals, and the like, and a system control unit 82 for comprehensively controlling each unit of the ultrasonic diagnostic apparatus 100 are provided.

  The ultrasonic probe 20 is for transmitting and receiving ultrasonic waves by bringing its front surface into contact with the surface of the subject. For example, M1 element in the horizontal direction (X direction) and M2 element in the vertical direction (Y direction). A two-dimensional array of ultrasonic vibration elements is provided at the tip. This ultrasonic vibration element is an electroacoustic transducer, and a piezoelectric vibration element such as PZT, a capacitive vibration element, or the like is used. The ultrasonic vibration element has a function of converting an electrical pulse into a transmission ultrasonic wave at the time of transmission and converting an ultrasonic reflected wave (reception ultrasonic wave) into an electric signal (reception signal) at the time of reception. ing.

  Next, the transmission / reception unit 10 shown in FIG. 2 includes a transmission unit 2 that supplies a drive signal to the ultrasonic vibration element group of the M0 channel formed by being commonly connected in an element selection unit 30 described later, and the element A receiving unit 3 is provided that performs second phasing addition on the reception signals collected in the M0 channel by the first phasing addition in the selection unit 30.

  The transmission unit 2 includes a rate pulse generator 11, a transmission delay circuit 12, and a drive circuit 13. The rate pulse generator 11 divides the continuous wave supplied from the reference signal generation unit 1 by dividing the continuous wave. A rate pulse that determines the repetition period of the transmission ultrasonic wave is generated. In addition, the transmission delay circuit 12 determines a delay time for converging the transmission ultrasonic wave to a predetermined depth and a delay time for radiating the transmission ultrasonic wave in a predetermined direction in order to obtain a narrow beam width in the transmission. Give to the pulse. Then, the drive circuit 13 generates a drive signal for driving the M0 channel ultrasonic vibration elements commonly connected in the element selection unit 30 based on the timing of the rate pulse.

  On the other hand, the receiving unit 3 includes a preamplifier 14, an A / D converter 15, and a beam former 16. The preamplifier 14 is for amplifying the received signal of the M0 channel supplied from the element selection unit 30 to ensure a sufficient S / N, and a high voltage supplied from the drive circuit 13 is provided in the first stage. A limiter circuit (not shown) is provided for protection from the drive signal. The reception signal amplified to a predetermined size by the preamplifier 14 is converted into a digital signal by the A / D converter 15 and sent to the beam former 16.

  The beam former 16 has a delay circuit and an adder circuit (not shown), and converges an ultrasonic reflected wave from a predetermined depth to the received signal of the M0 channel converted into a digital signal by the A / D converter 15. The delay time for convergence and the reception directivity of the ultrasonic reflected wave are sequentially changed to give a deflection delay time for scanning the patient, and then addition and synthesis (second phasing addition) are performed.

  The beam former 16 and the sub-array delay adder 33 of the element selector 30 already described have a so-called parallel simultaneous reception function of separately receiving each of the received ultrasonic waves from a plurality of directions.

  Next, the data generation unit 50 shown in FIG. 3 performs signal processing on the reception signal output from the beam former 16 of the reception unit 3 to generate B mode data, and the reception A color Doppler data generation unit 5 is provided that generates color Doppler data by processing the signal.

  The B mode data generation unit 4 includes an envelope detector 51 and a logarithmic converter 52. The envelope detector 51 performs envelope detection on the reception signal output from the beamformer 16 in the reception unit 3 of the transmission / reception unit 10, and the logarithmic converter 52 is a logarithm of the reception signal after the envelope detection. B-mode data for each scanning direction is generated by relatively emphasizing a small signal amplitude by the conversion process.

  On the other hand, the color Doppler data generation unit 5 includes a π / 2 phase shifter 54, mixers 55-1 and 55-2, and LPFs (low-pass filters) 56-1 and 56-2. Quadrature detection is performed on the received signal supplied from the receiver 3 to generate a complex signal (I signal and Q signal).

  The color Doppler data generation unit 5 further includes a Doppler signal storage circuit 58, an MTI filter 59, and an autocorrelation calculator 60. The complex signal obtained by the quadrature detection is temporarily stored in the Doppler signal storage unit 58, and then the MTI filter 59, which is a high-pass digital filter, is stored in the complex signal stored in the Doppler signal storage unit 58. The signal is read out, and the Doppler component (clutter component) caused by the reflex movement or pulsatile movement of the organ is reflected from this complex signal. The autocorrelation calculator 60 calculates an autocorrelation value for the Doppler signal of the blood flow information extracted by the MTI filter 59, and further, based on the autocorrelation value, an average blood flow velocity value and a variance value Further, color Doppler data is generated by calculating a power value and the like.

  Next, returning to FIG. 1, the data storage / processing unit 70 includes a data storage unit 6 and a data processing unit 7, and the data storage unit 6 is generated by the data generation unit 50 in units of the scanning direction. Mode data and color Doppler data are sequentially stored to generate three-dimensional or two-dimensional B-mode image data and color Doppler image data.

  On the other hand, the data processing unit 7 uses the three-dimensional B-mode image data and color Doppler image data generated in the data storage unit 6 and uses volume rendering image data, surface rendering image data, MIP (maximum intensity projection). ) Image processing is performed to generate image data, MPR (multi-planar reconstruction) image data, and the like.

  Next, the display unit 81 includes a display data generation circuit, a conversion circuit, and a monitor (not shown), and the B-mode image data and the color Doppler image data generated in the data storage / processing unit 70 are generated by the display data generation. In the circuit, processing such as scan conversion corresponding to a predetermined display form is performed to generate display data, and this display data is D / A converted and television format converted in the conversion circuit and displayed on the monitor. The

  On the other hand, the input unit 83 includes an input device such as a display panel, a keyboard, a trackball, a mouse, a selection button, and an input button on the operation panel, and inputs patient information, data collection conditions, display conditions, and the like. Various command signals are input.

  The system control unit 82 includes a CPU and a storage circuit (not shown), and the above-described various information input or set from the input unit 83 by the operator is stored in the storage circuit. Based on these pieces of information, the CPU controls the transmission / reception unit 10, the data generation unit 50, the data storage / processing unit 70, and further controls the element selection unit 30 described later and the overall system.

  Next, details of the element selection unit 30 that is an important component of the ultrasonic diagnostic apparatus according to the present embodiment will be described with reference to FIGS.

  FIG. 4 is a diagram showing a two-dimensional array of ultrasonic vibration elements already described and a plurality of subarrays configured by dividing the two-dimensional array into a predetermined size, with M1 elements in the X direction and M1 elements in the Y direction. The two-dimensional array of ultrasonic vibration elements in which M2 elements are arranged is divided into, for example, M0 subarrays SUB-11, SUB-12,..., Each having three elements arranged in the X direction and the Y direction.

  The element selection unit 30 of FIG. 1 supplies a drive signal to the ultrasonic vibration elements of the two-dimensional array and emits transmission ultrasonic waves in a predetermined direction. A plurality of ultrasonic vibration elements adjacent to each other in a predetermined direction from among the ultrasonic vibration elements S-11, S-12,... S-21, S-22,. And sub-array element connection section 32 (second element connection means) for connecting the commonly connected ultrasonic vibration elements between the sub-arrays. ing.

  Furthermore, when the element selection unit 30 receives the reception ultrasonic waves detected by the two-dimensionally arranged ultrasonic vibration elements and supplies the reception ultrasonic waves to the transmission / reception unit 10, for example, the element selection unit 30 includes a reception subarray formed by three elements × 3 elements. A subarray delay adder 33 that performs a first phasing addition on the received signal obtained from each ultrasonic transducer, and a supply of the drive signal generated by the transmitter 2 to the intersubarray element connector 32 A changeover switch (SW) 34 for switching the supply of the output signal of the subarray delay adder 33 to the receiver 3 is provided, and this changeover switch 34 outputs the output of the transmitter 2 via a M0 channel cable (not shown). And the input end of the receiving unit 3.

  FIG. 5 shows a method of connecting the sub-array ultrasonic vibration elements by the sub-array element connecting portion 31. For example, the ultrasonic vibration element S- of the sub-array SUB-11 of 3 elements × 3 elements shown in FIG. 11 to S-13, S-21 and S-23, and S-31 to S-33 are connected via switches SW-11 to SW-13, SW-21 and SW-23, SW-31 to SW-33. The ultrasonic vibration element S-22 connected to the lines L1 to L3 and arranged at the center of the subarray SUB-11 is directly connected only to the connection line L2.

  In this figure, S-11 to S-13 are connected to the connection line L3 via SW-11 to SW-13, respectively, and S-21 and S-23 are connected to SW-21 and SW-23. Connected to the connection line L2, and S-31 to S-33 are connected to the connection line L1 via the switches SW-31 to SW-33.

  In the connection method using the switching circuit described above, the case where the three elements in the Y direction in the sub-array SUB-11 are connected to the connection lines L1 to L3 has been described. Three direction elements (for example, [S-11, S-12, S-21], [S-13, S-22, S-31], [S-23, S-32, S-33]) It is also possible to connect to the connection lines L1 to L3.

  Next, a connection method for the ultrasonic transducer elements between adjacent subarrays performed by the intersubarray element connection unit 32 will be described with reference to FIG. In FIG. 6, reference numerals L1 to L3 shown at the right ends of the subarrays SUB11 to SUB13, SUB21 to SUB23, and SUB31 to SUB33 are connection lines L1 to L3 connected to the ultrasonic transducer elements in the subarray by the element connection portion 31 in the subarray. L3 is schematically shown, and the connection line L2 in each subarray is connected to the connection line L1 or the connection line L3 in any one of the three subarrays adjacent to each other via the switching circuit of the inter-subarray element connection unit 32. Connected to.

  For example, the connection line L2 of the sub-array SUB-13 is connected to the adjacent sub-arrays SUB-12, SUB-22, and SUB-23 via the switches SWW-12, SWW-22, and SWW-23. It is connected to the connection line L1 or the connection line L3 in any of the subarrays. That is, only one opening / closing part among the six opening / closing parts in SWW-12, SWW-22, and SWW-23 connected to the connection line L2 of SUB-13 is in a connected state.

  Similarly, the connection method of the connection line of the sub-array SUB-12 and the connection line of the adjacent sub-array is shown by the one-dot chain line in FIG. 6, and the connection line L2 of the sub-array SUB-23 and the connection line of the adjacent sub-array are connected. The method is indicated by a dashed line. In this figure, connection to three adjacent subarrays has been described, but connection to four adjacent subarrays including upper right or lower left may be performed.

  Next, a common connection method of ultrasonic vibration elements by the above-described intra-subarray element connection portion 31 and inter-subarray element connection portion 32 will be described with reference to FIGS.

  FIG. 7 shows a common connection method of the ultrasonic vibration elements in the sub-array. The element connection portion 31 in the sub-array and the central ultrasonic vibration element S-22 of the sub-array with reference to the transmission convergence point of the transmission ultrasonic waves. Select and commonly connect ultrasonic transducer elements in the same sub-array in a substantially equidistant direction, and make a common connection to other ultrasonic transducer elements in the same sub-array in the same direction as the common connection direction. . For example, as shown in FIGS. 7A to 7D, the common connection direction in the case of a 3 × 3 subarray is −45 degrees, 0 degrees, 45 degrees and 90 degrees with respect to the X direction. The degree direction can be set. Then, the ultrasonic vibration elements connected to the connection lines L1 to L3 of each sub-array in each common connection direction are set as shown in FIG.

Next, a connection method between adjacent subarrays by the inter-subarray element connection unit 32 will be described with reference to FIG. Here, in the four-character code Xa-Xb-Xc-Xd shown in FIG. 9, Θ ₋₄₅ , Θ ₀ , Θ ₄₅ , and Θ ₉₀ of the code Xa are the connection directions in the subarray SUBa −45 degrees, 0 degrees, 45 R, S, and D of Xb indicate the adjacent directions “right”, “lower right”, and “lower” of the adjacent sub-arrays connected to this sub-array, respectively.

Further, Θ ₋₄₅ , Θ ₀ , Θ ₄₅ , and Θ ₉₀ of the symbol Xc correspond to the connection directions of the ultrasonic vibration elements in the adjacent sub-array SUBb to be connected to −45 degrees, 0 degrees, 45 degrees, and 90 degrees, respectively. , L1 to L3 of the reference symbol Xd indicate connection lines of the adjacent subarray SUBb connected to the connection line connected to the central vibration element S-22 of the subarray SUBa.

For example, in the connection between the sub-array SUBa and the adjacent sub-array SUBb indicated by Θ ₄₅ -R-Θ ₀ -L1 in FIG. 9A, the direction is 45 degrees with respect to the central ultrasonic transducer S-22 of the sub-array SUBa. The arranged ultrasonic vibration elements S-11, S-22, and S-33 are connected in common by the connection line L2, and furthermore, the ultrasonic vibration elements S-13, S of the adjacent sub-array SUBb adjacent to the right side of the sub-array SUBa. A connection line L1 commonly connecting −23 and S-33 and a connection line L2 of the sub-array SUBa are connected.

  Similarly, FIG. 9B shows a case where the subarray SUBa is connected to the lower right adjacent subarray SUBb, and FIG. 9C shows a specific example where it is connected to the lower adjacent subarray SUBb. Indicates.

  In the sub-array element connecting portion 31 and the inter-sub-array element connecting portion 32, two ultrasonic vibration elements in a predetermined direction in the same sub-array commonly connected to the central ultrasonic vibration element of the sub-array and a predetermined direction in an adjacent sub-array The three ultrasonic vibration elements are connected to a predetermined output terminal of the transmission unit 2 in the transmission / reception unit 10 via the changeover switch 34 and a cable (not shown).

  Next, the adjacent sub-array is set as a new sub-array, and the new sub-array and the 6 ultrasonic transducer elements in the adjacent sub-array are commonly connected by the intra-sub-array element connecting portion 31 and the inter-sub-array element connecting portion 32 in the same procedure. These connected ultrasonic vibration elements are connected to the other output terminal of the transmission unit 2. Then, by repeating the above-described connection procedure, M0 ultrasonic vibration element groups and M0 channels are formed by common connection of six elements based on the central ultrasonic vibration element in each of the M0 subarrays. Connection to the output terminal of the transmitter 2 is performed.

(Image data generation procedure)
Next, an image data generation procedure using the ultrasonic diagnostic apparatus according to the present embodiment will be described with reference to FIGS. First, the operator inputs patient information through the input unit 83, and further selects an image data collection mode. Here, a case where 3D B-mode image data and 3D color Doppler image data are selected as the acquisition mode will be described, but 2D B-mode image data or 2D color Doppler image data in an arbitrary cross section may be used. Alternatively, it may be two-dimensional or three-dimensional tissue Doppler image data for imaging a function of a subject's heart wall or the like using a Doppler signal.

  Next, the number of ultrasonic vibration elements (M1 × M2) of the sub-array in transmission and the number of ultrasonic vibration elements (M1 ′ × M2 ′) in reception are set, and the number of output terminals of the transmission unit 2 or the reception unit 3 in the transmission / reception unit 10 is set. The number of subarrays equal to the number M0 of input terminals is formed. These pieces of information are stored in a storage circuit (not shown) of the system control unit 82. In the following, M1 = M1 ′ = M2 = M2 ′ = 3 is set in the same manner as in the description of the apparatus configuration described above, but the present invention is not limited to this. In addition, various conditions of the subarray in transmission and reception may be set in advance in the system control unit 82, for example.

  When the above initial setting is completed, the operator fixes the tip of the ultrasonic probe 20 (ultrasonic wave transmission / reception surface) to a predetermined position on the surface of the subject body, so that the first scanning direction ( Ultrasonic wave transmission / reception for obtaining B-mode data in the (θ1 direction) is performed.

  That is, the system control unit 82 in FIG. 1 supplies information on the transmission / reception direction (θ1) of ultrasonic waves and distance information to the transmission convergence point to the element selection unit 30, and receives the information. The sub-array inter-element connection section 31 and the inter-sub-array element connection section 32 are arranged in the same sub-array and adjacent sub-array as the central ultrasonic transducer elements of the transmission sub-array and the reception sub-array that have already been set. The two ultrasonic vibration elements are connected in common by the connection procedure described above.

  Next, the rate pulse generator 11 of FIG. 2 divides the reference signal supplied from the reference signal generator 1 to generate a rate pulse that determines the repetition period Tr of the ultrasonic pulse, and this rate pulse is This is supplied to the transmission delay circuit 12 of the M0 channel.

  The transmission delay circuit 12 gives the rate pulse a convergence delay time for converging the ultrasonic wave to a predetermined depth and a deflection delay time for transmitting the ultrasonic wave in the first scanning direction (θ1). This rate pulse is supplied to the drive circuit 13. Then, the M0 channel drive circuit 13 receives the impulse generated by the rate pulse drive or the drive signal having a predetermined waveform via the M0 channel cable and the center ultrasonic transducer elements of the M0 sub-arrays in the ultrasonic probe 20. The ultrasonic waves are supplied to the ultrasonic vibration elements in the same subarray and adjacent subarrays commonly connected to the central ultrasonic vibration element, and ultrasonic pulses are radiated in the first scanning direction.

  In this case, the transmission delay circuit 12 of the transmission unit 2 is based on the position of the central ultrasonic vibration element in each of the M0 subarrays, the ultrasonic wave transmission direction (θ1), the distance to the transmission convergence point, and the like. A preset transmission delay time is applied to the rate pulse supplied from the rate pulse generator 11, and the M0 channel rate pulse having a different delay time is supplied to the drive circuit 13. The drive signal of the M0 channel generated based on the timing of these rate pulses is transmitted through a cable (not shown), the changeover switch 34 of the element selector 30, the intra-subarray element connection section 31 and the intersubarray element connection section 32. Via the central ultrasonic vibration element in each sub-array and the five ultrasonic vibration elements commonly connected to the central ultrasonic vibration element.

  A part of the transmitted ultrasonic wave radiated to the subject is reflected at an interface or tissue between organs having different acoustic impedances. Further, when this ultrasonic wave is reflected by a moving reflector such as a heart wall or blood cell, the ultrasonic frequency is subjected to Doppler shift.

  The ultrasonic reflected wave (received ultrasonic wave) reflected by the tissue or blood cell of the subject is received by the ultrasonic vibration element arranged two-dimensionally by M1 × M2 in the ultrasonic probe 20 and converted into an electric signal (received signal). Further, the received signal of the M1 × M2 channel is given a predetermined first reception delay time in units of reception subarrays already set in the subarray delay addition unit 33 of the element selection unit 30, and the first phasing is performed. Addition is performed to form an addition output signal of the M0 channel. The method for setting the reception delay time is the same as in the case of the transmission delay time described above, the position of the ultrasonic transducer element and the ultrasonic wave receiving direction (θ1) in each of the M0 subarrays, It is set based on the distance to the reception convergence point.

  Next, the addition output signal of the M0 channel is supplied to the reception unit 3 of the transmission / reception unit 10 via the changeover switch 34 and the cable, amplified to a predetermined size by the preamplifier 14 of the reception unit 3, and then A / D The signal is converted into a digital signal by the converter 15. Further, the M0 channel reception signal converted into the digital signal is given a predetermined second reception delay time by the beamformer 16 based on the control signal of the system control unit 82, and the second phasing addition is performed. It is.

  The first reception delay time given by the sub-array delay adder 33 and the second reception delay time given by the beam former 16 of the receiver 3 are the distance to the position of each ultrasonic vibration element and the reception convergence point. Further, it is set based on the first scanning direction (θ1) or the like.

  FIG. 10 schematically shows the reception delay time given to each ultrasonic vibration element of the subarrays SUB11, SUB12, SUB13,... In the Y direction in the two-dimensional array shown in FIG. For the sake of simplicity, a case is shown in which a delay time that changes linearly with respect to the arrangement direction is given to the received signal from each ultrasonic vibration element.

  That is, for the reception signals obtained from the oscillating elements S-11, S-12, and S-13 in each subarray of SUB11, SUB12, SUB13,..., The subarray delay adding unit 33 performs the first reception delay time τ11. = 0, τ12, τ13 are given to perform the first phasing addition, and then the beamformer 16 gives the second reception delay times τx1, τx2, τx3,. To perform the second phasing addition. Thus, by supplying a relatively small first reception delay time to each ultrasonic transducer element in the subarray and performing the first phasing addition, the second phasing addition is performed in units of subarrays. The reception delay time close to the ideal delay time indicated by the broken line can be obtained with a relatively simple circuit configuration.

  The received signal subjected to the second phasing addition in the beamformer 16 is supplied to the B-mode data generation unit 4 of the data generation unit 50, subjected to envelope detection and logarithmic conversion, and then stored in the data storage of FIG. The data is stored in the data storage unit 6 in the processing unit 70.

  On the other hand, in the generation of color Doppler image data, a plurality of (L times) ultrasonic transmission / reception continuous in the first scanning direction is performed by the same procedure as described above in order to obtain the Doppler shift of the received signal. The Doppler signal is detected for the received signal obtained at this time.

  That is, the system control unit 82 performs the first ultrasonic transmission / reception for color Doppler in the first scanning direction. Then, the obtained reception signal is supplied to the color Doppler data generation unit 5, and a two-channel complex signal is generated from quadrature detection by the mixers 55-1 and 55-2 and the LPFs 56-1 and 56-2. Next, each of the real number component (I component) and the imaginary number component (Q component) of the complex signal is temporarily stored in the Doppler signal storage unit 58. Complex signals are collected by the same procedure for received signals obtained by the second through Lth ultrasonic transmission / reception in the first scanning direction and stored in the Doppler signal storage unit 58.

  When the storage of the complex signal obtained by the L times of ultrasonic transmission / reception in the first scanning direction is completed in the Doppler signal storage unit 58, the system control unit 82 stores the complex signal stored in the Doppler signal storage unit 58. Complex signal components corresponding to a predetermined position (depth) are sequentially read out from the signal and supplied to the MTI filter 59. Then, the MTI filter 59 performs a filtering process on the supplied complex signal component, for example, a reflected wave component from a fixed reflector such as a living tissue or a tissue Doppler component (clutter component) generated by the movement of a tissue such as a myocardium. And only the blood flow Doppler component resulting from the blood flow is extracted.

  Next, the autocorrelation calculator 60 to which the complex signal of the blood flow Doppler component is supplied from the MTI filter performs autocorrelation processing using this complex signal, and further, based on the autocorrelation processing result, the average velocity of blood flow A value, a variance value, a power value, etc. are calculated. Such calculation is also performed on other positions (depths) in the first scanning direction, and the calculated average velocity value, variance value, and power value of the blood flow are stored in the data storage / The data is stored in the data storage unit 6 in the processing unit 70.

  Similarly, the system control unit 82 performs ultrasonic transmission / reception in a plurality of preset directions (second scanning direction (θ2) to Pth scanning direction (θP)) in a three-dimensional space. The obtained B-mode data and color Doppler data are stored in the data storage unit 6 in the scanning direction unit.

  By the above procedure, the B mode data and color Doppler data obtained in units of the scanning direction are sequentially stored in the data storage unit 6 to generate three-dimensional B mode image data and color Doppler image data, and the data processing unit 7 performs volume rendering. And image processing such as MIP. The display data generation circuit of the display unit 81 performs processing such as scan conversion corresponding to a predetermined display form on the B-mode image data and color Doppler image data generated in the data storage / processing unit 70. Display data is generated, and this display data is D / A converted and television format converted in a conversion circuit (not shown) and displayed on the monitor.

  According to the embodiment of the present invention described above, a plurality of ultrasonic transducer elements arranged in two dimensions are divided into a predetermined size to form a plurality of subarrays, and then the radiation direction of transmission ultrasonic waves, transmission A plurality of ultrasonic transducers arranged in a predetermined direction in each subarray and a plurality of ultrasonic vibration elements arranged in a predetermined direction in an adjacent subarray adjacent to this subarray are connected in common based on the convergence point, the position of the subarray, etc. By doing so, it is possible to form an ultrasonic transducer group that allows simultaneous driving.

  According to this connection method, it is possible to radiate transmission ultrasonic waves using about 60% of all ultrasonic vibration elements that are two-dimensionally arranged, and an independent delay time for each of the ultrasonic vibration elements. It is possible to obtain a delay time accuracy substantially equal to that in the case where control is performed. For this reason, it is possible to significantly reduce the number of channels of the transmission unit and the cable without significantly degrading the transmission energy and the transmission directivity.

  In addition, the common connection is made by connecting the ultrasonic vibration elements in the predetermined direction in the predetermined sub-array and the adjacent sub-array in common in the sub-array, and the ultrasonic wave commonly connected in each sub-array. The switching circuit can be drastically reduced as compared with the method of Patent Document 1 by using the inter-sub-array element connecting portion (second element connecting means) for further connecting the vibration elements between the sub-arrays. For this reason, not only it becomes easy to provide these switching circuits in the ultrasonic probe, but also the amount of heat generated by the switching circuits can be suppressed.

  Further, the phasing addition at the time of reception in this embodiment is performed between the subarray delay adding unit (first phasing addition means) and the subarray which performs phasing addition on the reception signal obtained from the ultrasonic vibration element in the subarray. By using a beamformer (second phasing / adding means) that performs phasing addition of the above, it is possible to greatly reduce the number of channels of the receiving unit and cable without deteriorating the receiving sensitivity and receiving directivity characteristics. .

  As mentioned above, although the Example of this invention has been described, this invention is not limited to said Example, It can change and implement. For example, in the above-described embodiment, in order to reduce the number of cables and channels of the reception unit at the time of reception, a reception-only subarray delay addition unit is provided separately from the transmission-only subarray element connection unit and the intersubarray element connection unit. However, as shown in FIG. 11, the ultrasonic vibration element to be used at the time of transmission and reception may be selected using the intra-subarray element connection unit 31 and the inter-subarray connection unit 32. This method has an advantage that the circuit configuration can be simplified, although the reception directivity characteristic is somewhat deteriorated compared to the above embodiment.

  In the above-described embodiment, the case where the number of ultrasonic vibration elements in the sub-array is 3 elements × 3 elements is described. However, the present invention is not limited to this. For example, 2 elements × 2 elements, 4 elements × 4 elements may be used. It is also possible to set the number of elements in the X direction and the Y direction to be different as in the case of 3 elements × 4 elements.

  Furthermore, although the case where the number of elements of the transmitting sub-array and the receiving sub-array is equal is described, the number of elements may be different. For example, when performing parallel simultaneous reception at the time of reception, it is desirable that the reception directivity is made stronger than the transmission directivity by making the number of elements in the reception subarray larger than the number of elements in the transmission subarray.

  Further, although the connection between the central ultrasonic vibration element of the sub-array and the connection line is fixed connection, it may be connected via a switching circuit in the same manner as other ultrasonic vibration elements.

  On the other hand, the image data obtained by the ultrasonic diagnostic apparatus in the above embodiment may be three-dimensional image data (volume data), but is one or a plurality of two-dimensional image data in a cross section in an arbitrary direction. Also good. Further, the image data is not limited to B-mode image data, and may be, for example, color Doppler image data or tissue Doppler image data for observing blood flow information or functions such as the heart wall.

  In the above-described embodiment, the case where three-dimensional image data or two-dimensional image data is generated while sequentially changing the transmission / reception direction (angle) of the ultrasonic wave has been described. Or the above two methods may be combined.

  In the above-described ultrasonic diagnostic apparatus, quadrature phase detection is performed in the color Doppler data generation unit of the data generation unit. However, the quadrature phase detection is performed in the reception unit of the transmission / reception unit, and the obtained complex signal is subjected to the first detection. It is also possible to perform phasing addition of 2.

1 is a block diagram showing the overall configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The block diagram which shows the structure of the transmission / reception part in the Example. The block diagram which shows the structure of the data generation part in the Example. The figure which shows the two-dimensional arrangement | sequence of the ultrasonic vibration element divided by the some subarray in the Example. The figure which shows the specific example of the ultrasonic vibration element connection method by each ultrasonic vibration element in the subarray of the Example, and the element connection part in a subarray. The figure which shows the ultrasonic vibration element connection method between adjacent subarrays by the element connection part between subarrays of the Example. The figure which shows the common connection method of the ultrasonic vibration element in a subarray in the Example. The figure which shows the specific example of the ultrasonic vibration element connected to the common connection direction and each connection line in the subarray of the Example. The figure which shows the ultrasonic vibration element connection method between the subarrays by the element connection part between subarrays of the Example. The figure which shows typically the reception delay time supplied to the received signal of each ultrasonic transducer | vibrator by the subarray delay addition part and beam former of the Example. The block diagram which shows the whole structure of the ultrasound diagnosing device in the modification of the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reference signal generation part 2 ... Transmission part 3 ... Reception part 4 ... B-mode data generation part 5 ... Color Doppler data generation part 6 ... Data storage part 7 ... Data processing part 10 ... Transmission / reception part 20 ... Ultrasonic probe 30 ... Element Selection unit 31... Intra-subarray element connection unit 32... Inter-subarray element connection unit 33... Subarray delay addition unit 34.
DESCRIPTION OF SYMBOLS 50 ... Data generation part 70 ... Data storage and processing part 81 ... Display part 82 ... System control part 83 ... Input part 100 ... Ultrasonic diagnostic apparatus

Claims (10)

An ultrasonic probe including two-dimensionally arranged ultrasonic vibration elements;
First element connection means for commonly connecting a part of the plurality of ultrasonic vibration elements in each of a plurality of subarrays formed by dividing the two-dimensional array of ultrasonic vibration elements into a predetermined size;
A second element connecting means for further commonly connecting a part of the first element connecting means for each of the plurality of subarrays;
Transmitting means for supplying a drive signal to the ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means and transmitting ultrasonic waves in a predetermined direction of the subject;
Receiving means for phasing and adding reception signals obtained by the two-dimensional array of ultrasonic transducer elements and receiving ultrasonic waves from a direction substantially the same as the predetermined direction of the subject;
Image data generation means for generating image data based on a reception signal obtained by the reception means while changing the transmission direction and reception direction of the ultrasonic wave to the subject;
A display means for displaying the generated image data;
The ultrasonic diagnostic apparatus, wherein the first element connecting means and the second element connecting means commonly connect ultrasonic vibration elements that are substantially equidistant with respect to a convergence point of transmission ultrasonic waves. An ultrasonic probe including two-dimensionally arranged ultrasonic vibration elements;
First element connection means for commonly connecting a part of the plurality of ultrasonic vibration elements in each of a plurality of subarrays formed by dividing the two-dimensional array of ultrasonic vibration elements into a predetermined size;
A second element connecting means for further commonly connecting a part of the first element connecting means for each of the plurality of subarrays;
Transmission for transmitting ultrasonic waves in a predetermined direction of the subject by supplying a drive signal to the transmitting ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means. Means,
The received signals obtained by the receiving ultrasonic vibration element group commonly connected by the first element connecting means and the second element connecting means are phased and added to be substantially the same as the predetermined direction of the subject. Receiving means for receiving ultrasonic waves from a direction;
Image data generation means for generating image data based on a reception signal obtained by the reception means while changing the transmission direction and reception direction of the ultrasonic wave to the subject;
A display means for displaying the generated image data;
The first element connecting means and the second element connecting means commonly connect ultrasonic vibration elements that are substantially equidistant to at least one of a convergence point of transmission ultrasound and a convergence point of reception ultrasound. An ultrasonic diagnostic apparatus.   The first element connecting means includes the reference ultrasonic wave that is approximately equidistant from a distance between a reference ultrasonic vibration element set in advance in each subarray and a convergence point of the transmission ultrasonic wave or a convergence point of the reception ultrasonic wave. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein common connection is set based on position information of the ultrasonic vibration elements in the same subarray adjacent to the vibration elements.   The ultrasonic diagnostic apparatus according to claim 3, wherein the first element connecting unit sets an ultrasonic vibration element positioned substantially at the center of each sub-array as the reference ultrasonic vibration element.   The first element connection means sets a common connection including the reference ultrasonic vibration element or a common connection not including the reference ultrasonic vibration element, and the second element connection means is arranged in the subarrays adjacent to each other. The ultrasonic vibration element connected by the common connection including the reference ultrasonic vibration element in one subarray and the ultrasonic vibration element connected by the common connection not including the reference ultrasonic vibration element in the other subarray are connected. The ultrasonic diagnostic apparatus according to claim 3, wherein:   The ultrasonic diagnostic apparatus according to claim 1, further comprising a subarray forming unit, wherein the subarray forming unit forms a reception subarray and a transmission subarray.   First phasing addition means for phasing and adding reception ultrasonic waves received by the ultrasonic transducer elements of the two-dimensional array in units of receiving sub-arrays, and phasing addition by the first phasing addition 2. The ultrasonic diagnostic apparatus according to claim 1, further comprising second phasing addition means for phasing and adding received signals between subarrays.   9. The ultrasonic diagnosis according to claim 8, wherein the ultrasonic probe includes at least one of the first element connecting means, the second element connecting means, and the first phasing addition means. apparatus.   The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission unit supplies a drive signal to the second element connection unit and the first element connection unit via a cable.   8. The ultrasonic diagnostic apparatus according to claim 7, wherein the first phasing addition means supplies the phased and added received signal to the second phasing addition means via a cable.

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