Abstract:
An ultrasound system and method for forming ultrasound data corresponding to a receive scan line independent of a synthetic aperture. The ultrasound system includes the ultrasound data forming unit configured to: form scan line data corresponding to each of the receive scan lines by using data provided from the receive channels; form accumulated data by accumulating the scan line data corresponding to the receive scan lines of the same position; set a storing start position for storing the accumulated data based on the transmit synthesizing number; and store the accumulated data by shifting the storing start position by 1, thereby forming ultrasound data corresponding to each of the receive scan linen lines.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from Korean Patent Application Nos. 10-2009-0038479 (filed on Apr. 30, 2009) and 10-2010-0039290 (filed on Apr. 28, 2010), the entire subject matters of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure generally relates to an ultrasound system and method for forming ultrasound data, and more particularly to a system and method for forming ultrasound data independent of a synthetic aperture. 
       BACKGROUND 
       [0003]    Ultrasound systems have been extensively used in the medical field due to the systems non-invasive and non-destructive nature. Specifically, in the ultrasound system, there is no need to perform any surgical operation procedures. Using the ultrasound system allows a medical professional to see the inside of a target object as a high-resolution video image to facilitate operations. As such, the ultrasound system has become very popular in the medical field. 
         [0004]    The ultrasound system transmits ultrasound signals to the target object by using an ultrasound probe. The ultrasound probe has a plurality of transducer elements and can receive ultrasound signals (ultrasound echo signals) reflected from the target object, which then forms an ultrasound image showing the inside of the target object. 
         [0005]    To improve the resolution of the ultrasound image, a plurality of array type transducer elements are used. Using a number of the transducer elements prevents the ultrasound signal from being diffused compared to using a single transducer element. As such, the ultrasound signal can be electrically focused to thereby improve sensitivity. 
         [0006]    Focusing ultrasound signals includes transmit focusing and receive focusing. In the transmit focusing, the transmit order of the ultrasound signals transmitted from each of the transducer elements is determined by a distance difference between each of the transducer elements and the focusing point. As such, the ultrasound signals transmitted from each of the transducer elements, which contribute to a single transmitting/receiving of the ultrasound signals (i.e., formation of one scan line), are simultaneously added at one focusing point in phase. This causes the amplitude of the transmitting ultrasound signals (i.e., ultrasound beams) to peak. In the receive focusing, each of the ultrasound signals reaching the transducer elements are subject to time-delay. This allows the ultrasound signals reflected from the focusing point to be in phase. Many focusing points are required to improve the resolution of the ultrasound image. Further, to produce one ultrasound image, there must be a repetition of the same signal processing procedures for all the focusing points, which deteriorates the frame rate. 
         [0007]    To solve the above-described problem, dynamic receive focusing was used wherein transmit focusing points were fixed and receive focusing points were increased, which allowed the ultrasound signals to be finely focused. In the dynamic receive focusing, the transmit focusing points are fixed so that the resolution of the ultrasound image can be improved. As an alternative measure, there was proposed a method of using all transmit focusing signals of adjacent transmit scan lines to acquire ultrasound data of the transmit scan lines. 
         [0008]    Further, to improve the lateral resolution of the ultrasound image and the signal-to-noise ratio (SNR), it is ideal to direct the received signal obtained from all transducer elements (channels) contributed to a single reception of the ultrasound signals to a beam former. This implements synthetic aperture imaging (SAI) at a full frame rate, wherein the received signal constitutes more proper radio frequency (RF) data obtained from the received signal. To achieve this, however, it is necessary to simultaneously form low resolution images (LRIs) corresponding to all scan lines and update high resolution images (HRIs), which are already formed by using each of the LRIs. To do this, the received signals must be corresponded at all transducer elements, which are contributed to the single reception of the ultrasound signals, to each of the scan lines, thereby significantly increasing hardware complexity. 
       SUMMARY 
       [0009]    It is an object of the present disclosure to provide an ultrasound system and method of forming ultrasound data corresponding to each receive scan line independent of a synthetic aperture. 
         [0010]    An aspect of the present disclosure encompasses an ultrasound system configured to transmit ultrasound signals to a target object and receive ultrasound echo signals reflected therefrom to thereby form ultrasound data. In one embodiment, by way of non-limiting example, the ultrasound system comprises an ultrasound data forming unit having a plurality of receive channels, which is configured to form a plurality of receive scan lines based on the ultrasound echo signals. The ultrasound data forming unit is configured to: form scan line data corresponding to each of the receive scan lines by using data provided thereto from the receive channels; accumulate the scan line data corresponding to the receive scan lines of the same position to form accumulated data; set a storing start position for storing the accumulated data based on a transmit synthesis number; store the accumulated data by shifting the storing start position by one; and form ultrasound data corresponding to each of the receive scan lines. 
         [0011]    Another aspect of the present disclosure encompasses a method for use in a system including a storing unit with a plurality of storage areas and a plurality of receive channels. In another embodiment, the method for transmitting ultrasound signals to a target object and receiving ultrasound echo signals reflected therefrom to form ultrasound data, comprises the steps of: (a) forming scan line data corresponding to each of the plurality of receive scan lines based on data provided from the plurality of receive channels; (b) setting a storing start position in the plurality of storage areas based on the transmit synthesis number; (c) storing the scan line data as accumulated data in corresponding storage area of the storing start position by reference to the storing start position; (d) forming new scan line data corresponding to each of the receive scan lines based on data newly provided from the receive channels; (e) shifting the storing start position in the storage area to set a new storing start position; (f) storing new accumulated data, which are obtained by the accumulation of the accumulated data stored in the storage area and the new scan line data, in corresponding storage area of the new storing start position by reference to the new storing start position; and (g) repeating the steps (c) to (f) to form the ultrasound data corresponding to each of the receive scan lines based on the new accumulated data. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a block diagram showing the architecture of an ultrasound system in accordance with one embodiment of the present disclosure. 
           [0013]      FIG. 2  is a detailed block diagram showing an ultrasound data acquisition unit shown in  FIG. 1  in accordance with the embodiment of the present disclosure. 
           [0014]      FIG. 3  is a detailed block diagram showing an ultrasound data forming unit shown in  FIG. 2  in accordance with the embodiment of the present disclosure. 
           [0015]      FIG. 4  is an illustrative diagram showing transmit scan lines and receive scan lines in accordance with an embodiment of the present disclosure. 
           [0016]      FIG. 5  is an illustrative diagram showing the formation of ultrasound data in accordance with an embodiment of the present disclosure. 
           [0017]      FIG. 6  is an illustrative diagram showing an ultrasound data forming unit in accordance with another embodiment of the present disclosure. 
           [0018]      FIG. 7  is an illustrative diagram showing an ultrasound data forming unit in accordance with yet another embodiment of the present disclosure. 
           [0019]      FIG. 8  is an illustrative diagram showing an ultrasound data forming unit in accordance with yet another embodiment of the present disclosure. 
           [0020]      FIG. 9  is an illustrative diagram showing an ultrasound data forming unit in accordance with still yet another embodiment of the present disclosure. 
           [0021]      FIG. 10  is an illustrative diagram showing an ultrasound data forming unit in accordance with still yet another embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    A detailed description may be provided with reference to the accompanying drawings. 
         [0023]      FIG. 1  is a block diagram showing the architecture of an ultrasound system in accordance with one embodiment of the present disclosure which embodies the methods of the present invention. Referring to  FIG. 1 , the ultrasound system  100  may include a user input unit  110 , an ultrasound data acquisition unit  120 , a processor  130  and a display unit  140 . 
         [0024]    The user input unit  110  may receive information input by a user. In the embodiment, the input information may include transmit (Tx) synthesis information. The Tx synthesis information may include information related to the number of scan lines (receive scan lines) to be simultaneously formed by transmitting ultrasound signals once. The user input unit  110  may include a control panel, a mouse, a key board, etc. 
         [0025]    The ultrasound data acquisition unit  120  may transmit the ultrasound signals to a target object and receive ultrasound signals (i.e., ultrasound echo signals) reflected therefrom to thereby acquire ultrasound data. The ultrasound data acquisition unit  120  will be described in more detail with reference to  FIG. 2 . 
         [0026]      FIG. 2  is a detailed block diagram showing the ultrasound data acquisition unit shown in  FIG. 1  in accordance with the embodiment of the present disclosure. Referring to  FIG. 2 , the ultrasound data acquisition unit  120  may include an ultrasound probe  121 , a transmit signal forming unit  122  and an ultrasound data forming unit  123 . 
         [0027]    The ultrasound probe  121  may include a plurality of transducer elements  121   a , which allows electrical signals and ultrasound signals to be interchangeable. The ultrasound probe  121  may convert the electrical signals (hereinafter referred to as transmit signals) provided thereto from the transmit signal forming unit  122  into the ultrasound signals to be transmitted to the target object. The ultrasound probe  121  may receive ultrasound echo signals reflected from the target object to form the electrical signals (hereinafter referred to as receive signals), wherein the electrical signals are analog signals. 
         [0028]    The transmit signal forming unit  122  may form the transmit signals in view of the position of the transducer elements  121   a  and focusing points. In the embodiment, the transmit signal forming unit  122  may include a transmit focus delay memory (not shown) for storing therein delay patterns of the ultrasound signals to be transmitted to the target object through the transducer elements  121   a . Thus, the ultrasound signals transmitted from each of the transducer elements  121   a  are focused along the scan lines (hereinafter referred to as transmit (Tx) scan lines) to form an ultrasound beam. 
         [0029]    The ultrasound data forming unit  123 , which is responsive to the received signals provided thereto from the ultrasound probe  121 , may perform analog-to-digital conversion on the received signals to form digital data. The ultrasound data forming unit  123  may also form ultrasound data of each of the scan lines (hereinafter referred to as receive (Rx) scan lines) corresponding to the Tx scan lines based on the digital data input thereto. The ultrasound data forming unit  123  may be implemented by at least one application specific integrated circuit (ASIC) having a plurality of receive channels (not shown) as its inputs (i.e., a plurality of inputs). 
         [0030]      FIG. 3  is a detailed block diagram showing the ultrasound data forming unit shown in  FIG. 2  in accordance with the embodiment of the present disclosure. Referring to  FIG. 3 , the ultrasound data forming unit  123  may include a first data storing unit  310 , a focusing delay calculation unit (FDCU)  320 , a first data forming unit  330 , a second data forming unit  340 , a second data storing unit  350  and a control unit  360 . The ultrasound data forming unit  123  may further include an amplifying unit (not shown) configured to amplify the analog received signals provided thereto from the ultrasound probe  121 , as well as an analog-to-digital convert (ADC) (not shown) configured to convert the analog amplified received signals into digital data. 
         [0031]    The first data storing unit  310  may store the digital data provided thereto from a plurality of receive channels (not shown) therein. In the embodiment, the first data storing unit  310  may include a plurality of storage areas (not shown), each of which corresponding to each of the receive channels on a one-to-one basis and storing therein digital data corresponding thereto. 
         [0032]    The FDCU  320  may store a receive delay curve lookup table, which is used in receive-focusing the digital data in view of positions of the transducer elements  121   a  and focusing points. 
         [0033]    In general, the ASIC (the ultrasound data forming unit  123 ) may require receive delay curve lookup tables by the number of input channels (i.e., number of receive channels serviced by ASIC) in receive-focusing the digital data stored in the first data storing unit  310  to form one receive scan line. In the case of simultaneously forming the plurality of receive scan lines with a single transmission of the ultrasound signals, the ASIC may require receive delay curve lookup tables, which correspond to (number of receive channels serviced by ASIC)×(number of receive scan lines simultaneously formed). In this case, the ASIC may include a minimum number of receive delay curve lookup tables in view of the capacity of the ASIC. 
         [0034]    Thus, to minimize the number of the receive delay curve lookup tables, the receive delay curve lookup tables required for the plurality of receive scan lines simultaneously formed, may be shared. In case the receive scan lines simultaneously formed in the ASIC are placed adjacent to each other and are disposed at regular intervals on the transducer elements  121   a  of the ultrasound probe  121 , the receive delay curve lookup tables of the adjacent receive scan lines may be shared with each other. 
         [0035]    For example, the simultaneously-formation of 32 receive scan lines through the use of digital data of 32 receive channels requires 1024 (32×32) receive delay curve lookup tables. Alternatively, sharing the receive delay curve lookup tables of adjacent receive scan lines allows the number of the receive delay curve lookup table to be reduced. Assuming that all of the receive scan lines are disposed on the transducer elements  121   a  of the ultrasound probe  121  at regular intervals, M th  receive scan line may be in a curve on which receive delay curve of (M−1) th  receive scan line is shifted by one. In other words, if the distance between the (M −1 ) th  receive scan line and the receive channels is −15, −14, . . . , −0, 1, . . . , —, 16, then the distance between the M th  receive scan line and the receive channels is −16, −15, −14, . . . , 0, 1, . . . , 14, 15 and the position of the (M−1) th  receive scan line [−15 to 16] is shifted to the right by one in the M th  receive scan line. This allows a new position [−16] to be produced. As described above, the receive delay curve lookup tables for the M th  receive scan line may share  31  of the receive delay curves used in the (M−1) th  receive scan line. As such, it is only necessary to add one table to 32 receive delay curve lookup tables required for (M−1) th  receive scan line for focus of M th  receive scan line. As such, in the case of forming 32 receive scan lines, the required number of the scan delay curve lookup tables may be derived from (number of receive channels serviced by ASIC)+((number of receive scan lines simultaneously formed)−1). 
         [0036]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may time-delay the digital data stored in the first data storing unit  310  and simultaneously form data (hereinafter referred to as scan line data) corresponding to each of the receive scan lines. 
         [0037]    The second data forming unit  340  may accumulate scan line data corresponding to the receive scan lines of the same position among the scan line data provided thereto from the first data forming unit  330 , thereby producing accumulated data. 
         [0038]    The second data storing unit  350  may store the accumulated data produced at the second data forming unit  340  therein in a sliding manner. The sliding manner will be described below. In the embodiment, the second data storing unit  350  may include a plurality of storage areas (not shown) for storing the accumulated data therein. 
         [0039]    The control unit  360  may set a storage start position of the data (i.e., accumulated data) based on the input information (i.e., transmit synthesis information) provided thereto from the user input unit  110 . The control unit  360  may control the storage of the scan line data and the formation of the ultrasound data. Furthermore, the control unit  360  may control the storage of the digital data and the formation of the scan line data. 
         [0040]    A description will be made with reference to  FIGS. 4 and 5  as to an example for forming ultrasound data corresponding to the receive scan lines by using the ultrasound data forming unit having a plurality of receive channels as its input, when 5 receive scan lines are simultaneously formed with respect to one transmit scan line (i.e., when the number of transmit synthesis is 5). 
         [0041]      FIG. 4  is an illustrative diagram showing transmit scan lines and receive scan lines in accordance with an embodiment of the present disclosure.  FIG. 5  is an illustrative diagram showing the formation of ultrasound data in accordance with an embodiment of the present disclosure. 
         [0042]    The ultrasound probe  121  transmits ultrasound signals to a target object along a first transmit scan line Tx 0  and receives ultrasound echo signals reflected therefrom. A plurality of digital data is provided from each of the receive channels. The plurality of digital data is stored in a storing area (not shown) corresponding thereto. 
         [0043]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may apply receive-delays to the plurality of the digital data stored in the first data storing unit  310 , thereby producing scan line data Rx 0,0 , Rx 0,1  and Rx 0,2  of each of receive scan lines Rx 0  to Rx 2  corresponding to the first transmit scan line Tx 0 . 
         [0044]    The control unit  360  may set a first storing start position in the second data storing unit  350  based on the input information (i.e., transmit synthesis information) provided thereto from the user input unit  110 . As an example, the control unit  360  may set the first storing start position (SSP) in the second data storing unit  350  by the following equation (1). 
         [0000]        SSP =round ( K/ 2)  (1) 
         [0045]    In the equation (1), round ( )denotes rounding off to the nearest whole number and K indicates the number of the transmit synthesis. 
         [0046]    That is, the control unit  360  may set the storing area M 2  corresponding to the storing start position (SSS=3=round(5/2)) with reference to the first storing area M 0  of the second data storing unit  350 , as shown in  FIG. 5 . 
         [0047]    The second data forming unit  340  may accumulate scan line data corresponding to the receive scan lines of the same position, among the scan line data provided therefrom, the first data forming unit  330  under the control of the control unit  360  to thereby produce accumulated data. That is, as to the receive scan lines of the same position, the second data forming unit  340  may accumulate the scan line data provided from the first data forming unit  330  with the accumulated data already stored in the second data storing unit  350 , thereby forming new accumulated data. 
         [0048]    More specifically, the second data forming unit  340  may accumulate the scan line data Rx 0,0  provided thereto from the first data forming unit  330  with the accumulated data already stored in a storing area M 3  of the second data storing unit  350  by reference to a first storing start position M 2 , thereby producing accumulated data AD 1,0 . In this case, the accumulated data already stored in the storing area M 3  may be a stored predetermined value (0). In Ad i,j , i indicates an accumulated number and j indicates position of the receive scan lines. The accumulated data AD 1,0  is stored in a storing area of the second data storing unit  350 , i.e., storing area M 2  corresponding to the first storing start position under the control of the control unit  360 . 
         [0049]    The second data forming unit  340  may accumulate the scan line data Rx 0,1  provided thereto from the first data forming unit  330  with accumulated data already stored in a storing area M 4  of the second data storing unit  350 , thereby producing new accumulated data AD 1,1 . The accumulated data AD 1,1  is stored in the storing area M 3  of the second data storing unit  350  by reference to the first start storing start position M 2  under the control of the control unit  360 . 
         [0050]    The second data forming unit  340  may accumulate the scan line data RX 0,2  provided thereto from the first data forming unit  330  with accumulated data already stored in a storing area M 5  of the second data storing unit  350 , thereby producing accumulated data AD 1,2 . The accumulated data AD 1,2  is stored in the storing area M 4  of the second data storing unit  350  by reference to the first storing start position M 2  under the control of the control unit  360 . 
         [0051]    Next, the ultrasound probe  121  transmits ultrasound signals to the target object along a second transmit scan line Tx 0  and receives ultrasound echo signals reflected therefrom. A plurality of digital data is provided from each of the receive channels. The plurality of digital data is stored in a storing area (not shown) corresponding thereto. 
         [0052]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may apply receive-delays to the plurality of the digital data stored in the first data storing unit  310  to thereby form scan line data Rx 1,0 , Rx 1,1 , Rx 1,2  and Rx 1,3  of each of receive scan lines Rx 0 , Rx 1 , Rx 2  and Rx 3  corresponding to a second transmit scan line Tx 1 . 
         [0053]    The control unit  360  may set the storing area M 1 , which is shifted to the left by one, by reference to the first storing start position M 2  of the second data storing unit  350  as a new storing start position (hereinafter referred to as a second storing start position). 
         [0054]    Under the control of the control unit  360 , the second data forming unit  340  may accumulate scan line data corresponding to the receive scan lines of the same position to thereby form accumulated data. More specifically, the second data forming unit  340  may accumulate each of the scan line data Rx 1,0 , Rx 1,1 , Rx 1,2  and Rx 1,3  provided thereto from the first data forming unit  330  with each of the accumulated data AD 1,0 , AD 1,1 , AD 1,2  and 0 already stored in each of the storing areas M 2 , M 3 , M 4  and M 5  by reference to the second storing start position M 1  of the second data storing unit  350 , thereby producing new accumulated data AD 2,0 , AD 2,1 , AD 2,2  and AD 1,3 . Each of the new accumulated data AD 2,0 , AD 2,1 , AD 2,2  and AD 1,3  is stored in each of the storing areas M 1  to M 4  corresponding thereto by reference to the second storing start position M 1 . 
         [0055]    Next, the ultrasound probe  121  transmits ultrasound signals to the target object along a third transmit scan line Tx 2  and receives ultrasound echo signals reflected therefrom. A plurality of digital data is provided from each of the receive channels. The plurality of digital data is stored in a storing area (not shown) corresponding thereto. 
         [0056]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may apply receive-delays to the digital data stored in the first data storing unit  310  to thereby form scan line data Rx 2,0 , Rx 2,1 , Rx 2,2 , Rx 2,3  and Rx 2,4  of each of receive scan lines Rx 0 , Rx 1 , Rx 2 , Rx 3  and Rx 4  corresponding to the third transmit scan line Tx 2 . 
         [0057]    The control unit  360  may set the storing area M 0 , which is shifted to the left by one, by reference to the second storing start position M 1  of the second data storing unit  350  as a new storing start position (hereinafter referred to as a third storing start position). 
         [0058]    Under the control of the control unit  360 , as to the receive scan lines of the same position, the second data forming unit  340  may accumulate each of the scan line data Rx 2,0 , RX 2,1 , Rx 2,2 , Rx 2,3  and Rx 2,4  provided thereto from the first data forming unit  330  with each of the accumulated data AD 2,0 , AD 2,1 , AD 2,2 , AD 1,3  and 0 already stored in each of the storing areas M 1 , M 2 , M 3 , M 4  and M 5  by reference to the third storing start position M 0  of the second data storing unit  350 , thereby producing new accumulated data AD 3,0 , AD 3,1 , AD 3,2 , AD 2,3  and AD 1,4 . The formed accumulated data AD 3,0 , AD 3,1 , AD 3,2 , AD 2,3  and AD 1,4  are stored in the storing areas M 0  to M 4  based on the third storing start position M 0  under the control of the control unit  360 . 
         [0059]    Next, the ultrasound probe  121  transmits ultrasound signals to the target object along a fourth transmit scan line Tx 3  and receives ultrasound echo signals reflected therefrom. A plurality of digital data is provided from each of the receive channels. Each of the plurality of digital data is stored in a corresponding storing area (not shown) of the first data storing unit  310 . 
         [0060]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may apply receive-delays to the digital data stored in the first data storing unit  310  to thereby form scan line data Rx 3,1 , Rx 3,2 , Rx 3,3 , RX 3,4  and Rx 3,5  of each of the receive scan lines Rx 1 , Rx 2 , Rx 3 , Rx 4  and Rx 5  corresponding to the fourth transmit scan line Tx 3 . 
         [0061]    Since the third storing start position of the second data storing unit  350  is the first storing area M 0 , no further setting on a new storing start position is performed at the control unit  360 . 
         [0062]    Under the control of the control unit  360 , as to the receive scan lines of the same position, the second data forming unit  340  may accumulate each of the scan line data Rx 3,1 , Rx 3,2 , Rx 3,3 , Rx 3,4  and Rx 3,5  provided thereto from the first data forming unit  330  with each of the accumulated data AD 3,1 , AD 3,2 , AD 2,3 , AD 1,4  and 0 already stored in each of the storing areas M 0  to M 5  by reference to the third storing start position M 0  of the second data storing unit  350 , thereby producing new accumulated data AD 4,1 , AD 4,2 , AD 3,3 , AD 2,4  and AD 1,5 . Each of the new accumulated data AD 4,1 , AD 4,2 , AD 3,3 , AD 2,4  and AD 1,5  is stored in each of storing areas M 0  to M 4  corresponding thereto by reference to the third storing start position M 0  under the control of the control unit  360 . In this case, the accumulated data AD 3,0  is outputted as the ultrasound data corresponding to the receive scan line Rx 0 , without further storing in the second data storing unit  350 . 
         [0063]    Next, the ultrasound probe  121  transmits ultrasound signals to the target object along a fifth transmit scan line Tx 4  and receives ultrasound echo signals reflected therefrom. A plurality of digital data is provided from each of the receive channels. Each of the digital data is stored in a corresponding storing area (not shown) of the first data storing unit  310 . 
         [0064]    Based on the receive delay curve lookup tables stored in the FDCU  320 , the first data forming unit  330  may apply receive-delays to the digital data stored in the first data storing unit  310  to thereby form scan line data Rx 4,2 , Rx 4,3 , RX 4,4 , RX 4,5  and Rx 4,6  of each of receive scan lines Rx 2 , Rx 3 , Rx 4 , Rx 5  and Rx 6  corresponding to the fifth transmit scan line Tx 4 . 
         [0065]    Since the third storing start position of the second data storing unit  350  is the first storing area M 0 , no further setting on a new storing start position is performed at the control unit  360 . 
         [0066]    Under the control of the control unit  360 , as to the receive scan line of the same position, the second data forming unit  340  may accumulate each of the scan line data Rx 4,2 , Rx 4,3 , Rx 4,4 , Rx 4,5  and Rx 4,6  provided thereto from the first data forming unit  330  with each of the accumulated data AD 4,1 , AD 4,2 , AD 3,3 , AD 2,3 , AD 1,5  and 0 already stored in each of the storing areas M 0  to M 5  by reference to the third storing start position M 0  of the second data storing unit  350 , thereby producing new accumulated data AD 5,2 , AD 4,3 , AD 3,4 , AD 2,5  and AD 1,6 . Each of the new accumulated data AD 5,2 , AD 4,3 , AD 3,4 , AD 2,5  and AD 1,6  is stored in each of the storing area M 0  to M 4  by reference to the third storing start position M 0  under the control of the control unit  360 . In this case, the accumulated data AD 4,1  is outputted as the ultrasound data corresponding to the receive scan line Rx 1  without further storing in the second data storing unit  350 . 
         [0067]    The ultrasound data forming unit  123  may produce ultrasound data AD 5,2 , AD 5,3 , . . . corresponding to each of the receive scan lines Rx 2 , Rx 3 , . . . by repeating the above-mentioned procedures. 
         [0068]      FIG. 6  is an illustrative diagram showing the ultrasound data forming unit in accordance with an embodiment of the present disclosure. Referring to  FIG. 6 , the ultrasound data forming unit  123  may have 32 receive channels ch 0  to ch 31  as its inputs. In order words, the ultrasound data forming unit  123  may include an ASIC  610  with 32 inputs. 
         [0069]    As shown in  FIG. 3 , the ASIC  610  may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 . 
         [0070]    The ASIC  610  may set a storing start position (SSP=16) of the second data storing unit  350  based on a transmit synthesis number (K=32) and shift to the left by one the storing start position of the second data storing unit  350  with respect to each of the transmit scan lines every transmission of the ultrasound signals. The ASIC  610  may accumulate scan line data corresponding to the receive scan lines of the same position to thereby produce accumulated data. Next, each of the accumulated data, which is produced by reference to the storing start position, is stored in a corresponding storing area of the second data storing unit  350 . 
         [0071]    Thus, if the scan line data corresponding to the receive scan lines of the same position are accumulated (i.e., synthesized) by (transmit synthesis number/2) or the transmit synthesis number, and no storing area to be further shifted in the second data storing unit  350  is detected, then the ASIC  610  may output accumulated data AD 16,0 , AD 17,0 , AD 18,0 , . . . output from the second data storing unit  350  as ultrasound data corresponding to each of the receive scan lines Rx 0 , Rx 1 , Rx 2 , . . . . 
         [0072]    In accordance with the embodiment, in case the ultrasound data of the receive scan lines is formed with the help of the ASIC  610  having 32 receive channels as its inputs, the number of the ASIC may be increased by the transmit synthesis number rather than the number of the total receive scan lines. This allows further simple implementations of the ultrasound data forming unit  123  over the prior art. 
         [0073]    Even though the embodiment has been described with respect to the ultrasound data forming unit  123  having 32 receive channels as its inputs (i.e., 32 inputs), in another embodiment, the ultrasound data forming unit  123  may have 128 receive channels as its inputs (i.e., 128 inputs), as shown in  FIG. 7 . In this case, the ultrasound data forming unit  123  may include first to fourth ASICs  710  to  740 , each of which has 32 receive channels as its inputs. Also, each of the first to fourth ASICs  710  to  740  may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . 
         [0074]      FIG. 8  is an illustrative diagram showing an ultrasound data forming unit in accordance with another embodiment of the present disclosure. Referring to  FIG. 8 , the ultrasound data forming unit  123  may include 64 receive channels ch 0  to ch 63  as its inputs, i.e., 64 inputs. The ultrasound data forming unit  123  may further include a first ASIC  810  and a second ASIC  820 . 
         [0075]    The first ASIC  810  may have 32 receive channels ch 0  to ch 31  as its inputs. The first ASIC  810  may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . The first ASIC  810  may further include an adding unit  370 . 
         [0076]    The first ASIC  810  may form ultrasound data AD 16,0 , AD 17,1 , . . . corresponding to the receive scan lines Rx 0 , Rx 1 , . . . based on the digital data provided thereto from the receive channels ch 0  to ch 31 , as described above. 
         [0077]    The second ASIC  820  may have 32 receive channels ch 31  to ch 63  as its inputs. The second ASIC  820  may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . The second ASIC  820  may further include the adding unit  370 . 
         [0078]    The second ASIC  820  may form ultrasound data AD′ 16,0 , AD′ 17,1 , . . . corresponding to the receive scan lines Rx 0 , Rx 1 , . . . based on the digital data provided thereto from the receive channels ch 31  to ch 63 . The second ASIC  820  may add the ultrasound data AD 16,0 , AD 17,1 , . . . provided thereto from the first ASIC  810  and the ultrasound data AD′ 16,0 , AD′ 17,1 , . . . provided thereto from the second ASIC  820  through the help of the adding unit  370 , thereby outputting the ultrasound data corresponding to the receive scan lines Rx 0 , Rx 1 , . . . . At this time, the adding unit  370  may perform an addition on ultrasound data corresponding to the receive scan lines of the same position. 
         [0079]    Even though the embodiment has been described for the addition of the ultrasound data from the first ASIC  810  and the ultrasound data from the second ASIC  820  at the adding unit  370  of the second ASIC  820 , in another embodiment, the addition of the ultrasound data from the first ASIC  810  and the ultrasound data from the second ASIC  820  may be performed at the adding unit  370  of the first ASIC  810 . 
         [0080]      FIG. 9  is an illustrative diagram showing an ultrasound data forming unit in accordance with yet another embodiment of the present disclosure. The ultrasound data forming unit  123  may define an ASIC group  910  having a plurality of ASICs based on the transmit synthesis number. 
         [0081]    As an example, each of the first and second ASICs  911  and  912  may have 32 receive channels ch 0  to ch 31  as its inputs and simultaneously form 32 receive scan lines, then the ultrasound data forming unit  123  may define the ASIC group  910  having the first and second ASICs  911  and  912  based on the transmit synthesis number (K=64), as shown in  FIG. 9 . Herein, each of the first and second ASICs  911  and  912  may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . 
         [0082]    The ultrasound data forming unit  123  may allocate indexes M 0  to M 31  to the storing areas of the second data storing unit  350  in the first ASIC  911  and allocate indexes M 32  to M 63  to the storage areas of the second data storing unit  350  in the second ASIC  912 . Thus, the ultrasound data forming unit  123  may form the ultrasound data of the receive scan lines in a sliding manner, as shown in  FIG. 9 . 
         [0083]      FIG. 10  is an illustrative diagram showing an ultrasound data forming unit in accordance with still yet another embodiment of the present disclosure. The ultrasound data forming unit  123  may define a plurality of ASIC groups based on the number of receive channels and the transmit synthesis number. 
         [0084]    As an example, when the number of the receive channels is  64  and each of the first to fourth ASICs  1011 ,  1012 ,  1021  and  1022  has 32 receive channels ch 0  to ch 31  as its inputs to simultaneously form 32 receive scan lines, the ultrasound data forming unit  123  may define a first ASIC group  1010  and an second ASIC group  1020  based on the transmit synthesis number (K=64), as shown in  FIG. 10 . 
         [0085]    The first ASIC group  1010  may have 32 receive channels ch 0  to ch 31  as its inputs. The first ASIC group  1010  may include the first ASIC  1011  and the second ASIC  1012 . Herein, each of the first ASIC  1011  and the second ASIC  1012  may have 32 receive channels ch 0  to ch 31  as its inputs and may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . Each of the first ASIC  1011  and the second ASIC  1012  may further include the adding unit  370 . The first ASIC group  1010  may form the ultrasound data AD 16,0 , AD 17,1 , . . . corresponding to the receive scan lines Rx 0 , Rx 1 , . . . , as described above. 
         [0086]    The second ASIC group  1020  may have 32 receive channels ch 32  to ch 63  as its inputs. The second ASIC group  1020  may include the third ASIC  1021  and the fourth ASIC  1022 . Herein, each of the third ASIC  1021  and the fourth ASIC  1022  may have 32 receive channels ch 32  to ch 63  as its inputs and may include the first data storing unit  310 , the FDCU  320 , the first data forming unit  330 , the second data forming unit  340 , the second data storing unit  350  and the control unit  360 , as shown in  FIG. 3 . Each of the third ASIC  1021  and the fourth ASIC  1022  may further include the adding unit  370 . The second ASIC group  1020  may form the ultrasound data AD′ 16,0 , AD′ 17,1 , . . . corresponding to the receive scan lines Rx 0 , Rx 1 , . . . , as described above. The second ASIC group  1020  may add the ultrasound data AD 16,0 , AD 17,1 , . . . provided thereto from the first ASIC group  1010  and the ultrasound data AD′ 16,0 , AD′ 17,1 , . . . provided thereto from the second ASIC group  1020  through the use of the adding unit  370  of the third ASIC  1021  to thereby output ultrasound data corresponding to the receive scan lines Rx 0 , Rx 1 , . . . . At this time, the adding unit  370  may add ultrasound data corresponding to the receive scan lines of the same position. 
         [0087]    Even though the embodiment has been described for the addition of the ultrasound data from the first ASIC group  1010  and the ultrasound data from the second ASIC group  1020  at the adding unit  370  of the third ASIC  1021 , in another embodiment, the addition of the ultrasound data from the first ASIC group  1010  and the ultrasound data from the second ASIC group  1020  may be performed at the adding unit  370  of at least one of the first to fourth ASICs  1011  to  1022 . 
         [0088]    Referring back to  FIG. 1 , the processor  130  may be connected with the user input unit  110  and the ultrasound data acquisition unit  120 . The processor  130  may process the ultrasound data provided thereto from the ultrasound data acquisition unit  120  to form an ultrasound image. The display unit  140  may display the ultrasound image formed at the processor  130 . 
         [0089]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. 
         [0090]    As an example, even though, in the above embodiments, setting of data storing start positions by the sliding manner are performed based on the transmit synthesis information provided from the user input unit  110 , in another embodiment, automatic setting of the transmit synthesis number allows the data storing start positions to be set by the sliding manner based on the transmit synthesis number set. 
         [0091]    Since the ultrasound data corresponding to each of the receive scan lines may be formed independent of the synthetic aperture as described above, the ultrasound system in accordance with the present disclosure will be implemented with low cost and low complexity.