Abstract:
An ultrasonic probe of a radial scan type mountable on an ultrasonic observation apparatus, which inputs and outputs M numbers of signals in parallel, comprises the following: N (N&gt;M) numbers of ultrasonic transducers disposed on an outer periphery of a tip, and grouped into plural sensor element groups activated in sequence, each of which has M numbers of ultrasonic transducers; N numbers of first signal lines respectively connected to the N numbers of ultrasonic transducers for transmitting a drive signal for driving the ultrasonic transducers and an echo signal from within a living organism; M numbers of second signal lines connected to the ultrasonic observation apparatus; and a multiplexer disposed between the first signal lines and the second signal lines, which selectively switches M numbers of the first signal lines for respectively connecting to the second signal lines according to the sensor element group to be activated.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an ultrasonic probe of a radial scan type which is compatible with an ultrasonic probe of a convex scan type, an ultrasonic observation apparatus which is capable of connecting the ultrasonic probes of the radial scan type and the convex scan type, and an ultrasonic diagnosing system. 
     2. Background Arts 
     Recently, in a field of medical care, a medical diagnosis using ultrasonic images is widely used. In an ultrasonic diagnosis, an ultrasonic is emitted to a required area of a living organism from an ultrasonic probe, and an echo reflected from within the living organism is received and converted into an electronic signal. The echo signal is analyzed and converted into an image. Further, an ultrasonic probe of an electronic scan type is also known, which is provided with plural ultrasonic transducers for transmitting and receiving the ultrasound. The ultrasonic probe of the electronic scan type selectively drives the ultrasonic transducers by using an electronic switch or the like. 
     As the ultrasonic probe of the electronic scan type, there are a convex scan type and a radial scan type (see Japanese Patent Laid-Open Publication No. 2-134142). The ultrasonic probe of the convex scan type has, plural (for instance, 94 to 128) ultrasonic transducers disposed in a sector shape on a tip of the probe. The ultrasonic probe of the radial scan type has a plurality of (for instance, 360) ultrasonic transducers all around an outer periphery of a tip of the probe. 
       FIG. 9  shows a conventional ultrasonic diagnosing system  100  of a convex scan type. The ultrasonic diagnosing system  100  is constructed of an ultrasonic probe  101  and an ultrasonic observation apparatus  102  to which the ultrasonic probe  101  is connected. It is possible to design an ultrasonic observation apparatus of a radial scan type by using a structure of the ultrasonic observation apparatus of the convex scan type. However, since the ultrasonic transducers of the radial scan type has more number of ultrasonic transducers, it is necessary to increase the number of input/output lines in each circuit. For instance, terminals of a second connector  105 , input lines of a multiplexer (MP)  108 , control lines of a scan controller  107  and the like should be increased in number. Likewise, a beamformer (BF)  111  should be modified according to the increase in the number of sound rays forming the ultrasonic image. In the modification, it becomes necessary to newly design the multiplexer  108 , the scan controller  107  and the BF  111  in accordance with the number of the ultrasonic transducers, which result in a long-term development and an increasing cost. 
     Further, an ultrasonic observation apparatus, which is capable of applying both the ultrasonic probes of the convex scan type and the radial scan type, is desired. In particular, it is preferable that the ultrasonic observation apparatus of the convex scan type can be easily modified so as to connect the ultrasonic probe of the radial scan type. 
     SUMMARY OF THE INVENTION 
     A main object of the present invention is to provide a compatible ultrasonic observation apparatus which is capable of connecting ultrasonic probes of a convex scan type and a radial scan type. 
     Another object of the present invention is to provide a compatible ultrasonic observation apparatus and an ultrasonic diagnosing system, which can be easily manufactured at a low cost, by utilizing a structure of the ultrasonic observation apparatus of the convex scan type. 
     Further another object of the present invention is to provide a compatible ultrasonic observation apparatus which is manufactured by modifying the ultrasonic observation apparatus of the convex scan type with ease at low cost. 
     Further another object of the present invention is to provide an ultrasonic probe of a radial scan type which is compatible with the ultrasonic probe of the convex scan type. 
     In order to achieve the above and other objects, the ultrasonic probe of the radial scan type according to the present invention includes a multiplexer disposed between N numbers of first signal lines and M (N&gt;M) numbers of second signal lines. On an outer periphery of a tip of the ultrasonic probe, N numbers of ultrasonic transducers are disposed. The ultrasonic transducers are respectively connected to the first signal lines. The first signal line transmit a drive signal for driving the ultrasonic transducer, and an echo signal from within a living organism. The second signal lines are connected to the ultrasonic observation apparatus which inputs and outputs M numbers of signals in parallel through a connector section thereof. To the ultrasonic observation apparatus, the ultrasonic probe of the convex scan type, which has M numbers of ultrasonic transducers on an outer periphery of a tip of the probe, can be connected in addition to the ultrasonic probe of the radial scan type. The multiplexer selects M numbers of ultrasonic transducers included in one of sensor element groups among N numbers of ultrasonic transducers to connect to the ultrasonic observation apparatus. 
     N numbers of ultrasonic transducers are disposed throughout the outer periphery at a predetermined pitch. N numbers of ultrasonic transducers are grouped into four sensor element groups. The plural ultrasonic transducers disposed at a boundary of two adjacent sensor element groups are contained in the two adjacent sensor element groups. It is preferable that the ultrasonic transducer is provided in an endoscope. 
     The ultrasonic observation apparatus of the present invention includes a connector section for inputting and outputting M numbers of signals in parallel, a type identifier, and a scan controller. The type identifier identifies a type of the ultrasonic probe mounted through the connector section thereof. The scan controller selects one of a first mode and a second mode according to the type identification of the type identifier. The first mode is applied to the ultrasonic probe of the radial scan type, and the second mode is applied to the ultrasonic probe of the convex scan type. In the first mode, a control signal is output for a switching operation of a multiplexer incorporated in the ultrasonic probe of the radial scan type. In the second mode, the control signal is not output. 
     The ultrasonic diagnosing system of the present invention includes the ultrasonic probe of the radial scan type and the ultrasonic observation apparatus on which the ultrasonic probe of the radial scan type is mounted through the connecter. The ultrasonic probe of the radial scan type includes the N numbers of ultrasonic transducers disposed on the outer periphery of the tip of the probe, the N numbers of first signal lines respectively connected to the N numbers of ultrasonic transducers, M numbers of second signal lines and a multiplexer disposed between the first signal lines and the second signal lines. The multiplexer selectively switches M numbers of first signal lines to connect to the second signal lines. The ultrasonic observation apparatus includes the connector section for inputting and outputting M numbers of signals in parallel and a scan controller. The scan controller performs the switching operation of the multiplexer incorporated in the ultrasonic probe of the radial scan type. The ultrasonic observation apparatus further includes the type identifier which identifies a type of an ultrasonic probe mounted on the connector. The scan controller selects the first mode for the ultrasonic probe of the radial scan type, and the second mode for the ultrasonic probe of the convex scan type according to the type identification of the type identifier. In the first mode, the multiplexer performs the switching operation. In the second mode, the switching operation is not performed. 
     In a preferable embodiment, the ultrasonic observation apparatus of the present invention includes the connector section, a first multiplexer and a second multiplexer. The first signal lines, which are connected to the ultrasonic transducers, are connectable to the connector section. The first multiplexer selectively switches M numbers of first signal lines and connect to the M numbers of second signal lines. The second multiplexer selectively switches L (N&gt;M&gt;L) numbers of second signal lines to connect to a transmitter, which transmits the drive signal, or a receiver which receives the echo signal. 
     In a preferable embodiment of the present invention, the ultrasonic diagnosing system includes the ultrasonic probe of the radial scan type in which N numbers of ultrasonic transducers are disposed on the outer periphery of the tip of the probe, and the ultrasonic observation apparatus on which the ultrasonic probe of the radial scan type is mounted through the connector section. L numbers of ultrasonic transducers are simultaneously driven as one block. At least one of ultrasonic transducers is shifted every time the drive signal for driving the ultrasonic transducer is transmitted or the echo signal is received from the living organism. An ultrasonic image is generated from the echo signal sequentially received on the block basis. The ultrasonic observation apparatus includes the first multiplexer, the second multiplexer and the scan controller. The first multiplexer selectively switches M (N&gt;M&gt;L) numbers of first signal lines to connect to the M numbers of second signal lines. The second multiplexer selectively switches L numbers of second signal lines to connect to the transmitter for transmitting the drive signal or the receiver for receiving the echo signal. The scan controller controls the switching operation of the first and second multiplexers. 
     In a further preferable embodiment of the present invention, the ultrasonic observation apparatus includes the connector section, on which the ultrasonic probe is mounted, and the multiplexer. The N numbers of first signal lines, which are respectively connected to the ultrasonic transducers, are connectable to the connector section. A multiplexer selectively switches L (N&gt;L) numbers of first signal lines for connecting to L numbers of second signal lines. The second signal lines are connected to the transmitter for transmitting the drive signal and the receiver for receiving the echo signal. It is preferable to use a programmable logic circuit, in which an arbitrary logic is reprogrammable, as the multiplexer. 
     In a further preferable embodiment of the ultrasonic diagnosing system of the present invention, the ultrasonic probe of the radial scan type includes the first multiplexer which selectively switches M numbers of first signal lines to connect to the second signal lines. The ultrasonic observation apparatus includes the second multiplexer and the scan controller. The second multiplexer selectively switches L numbers of second signal lines to connect to the transmitter for transmitting the drive signal or the receiver for receiving the echo signal. 
     In a still further preferable embodiment of the present invention, the ultrasonic diagnosing system includes the multiplexer disposed in one of the ultrasonic probe of the radial scan type or the ultrasonic observation apparatus. The multiplexer selects M numbers of signal lines out of the N numbers of signal lines. 
     Since the ultrasonic probe of the radial scan type uses the same number of output lines as the ultrasonic probe of the convex scan type by the function of the multiplexer, the ultrasonic probe of the radial scan type has become compatible with the ultrasonic probe of the convex scan type. Further, the ultrasonic probe of the radial scan type can be manufactured at low cost by only incorporating the multiplexer. 
     Since the ultrasonic observation apparatus of the present invention has a function to switch the multiplexer when the ultrasonic probe of the radial scan type incorporated with the multiplexer is connected, so that both the ultrasonic probes of the radial scan type and the convex scan type can be applied. Further, since the ultrasonic observation apparatus of the present invention utilizes the fundamental structure of the ultrasonic observation apparatus of the convex scan type, the manufacturing or the modification thereof can be performed at low cost. 
     Since the ultrasonic observation apparatus of the preferable embodiment has at least one multiplexer and divides the signals from the ultrasonic probe of the radial scan type, the configuration of the conventional ultrasonic observation apparatus of the convex scan type can be utilized. Accordingly, the ultrasonic observation apparatus can be easily designed and manufactured at low cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above objects and advantages of the present invention will become apparent from the following detailed descriptions of the preferred embodiments when read in association with the accompanying drawings, which are given by way of illustration only and thus do not limit the present invention. In the drawings, the same reference numerals designate like or corresponding parts throughout the several views, and wherein: 
         FIG. 1  is a schematic view showing a first embodiment of an ultrasonic diagnosing system; 
         FIG. 2  is an explanatory view showing a method for dividing ultrasonic transducers into plural sensor element groups; 
         FIG. 3  is a schematic view showing a multiplexer; 
         FIG. 4  is a flow chart showing operational steps of the ultrasonic diagnosing system when an ultrasonic probe of a convex scan type is connected; 
         FIG. 5  is a flow chart showing the operational steps of the ultrasonic diagnosing system when an ultrasonic probe of a radial scan type is connected; 
         FIG. 6  is a schematic view showing a second embodiment of the ultrasonic diagnosing system; 
         FIG. 7  is a schematic view showing a third embodiment of the ultrasonic diagnosing system; 
         FIG. 8  is a schematic view showing a multiplexer; and 
         FIG. 9  is a schematic view showing a conventional ultrasonic diagnosing system. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In  FIG. 1 , an ultrasonic diagnosing system  2  as a first embodiment of the present invention is constructed of an ultrasonic probe  10  and an ultrasonic observation apparatus  11 . The ultrasonic probe  10  is of a radial scan type which is incorporated with a cylindrical substrate  13  with 360 ultrasonic transducers  12  disposed at regular intervals on an outer periphery on a tip of a sheath (not shown) formed of a flexible member. The ultrasonic probe  10  is connected to the ultrasonic observation apparatus  11  by inserting a first connector  14 , which is provided at a trailing end of a code (not shown) extended from the sheath, into a second connector  15  provided in the ultrasonic observation apparatus  11 . 
     The 360 ultrasonic transducers  12  are respectively connected to ends of 360 first signal lines  16  which transmit drive signals from a transmitter  23  (which will be described later) of the ultrasonic observation apparatus  11  and echo signals reflected from within a living organism. The other ends of the first signal lines  16  are respectively connected to a multiplexer (MPa)  17 . 
     As shown in  FIG. 2 , the 360 ultrasonic transducers  12  are divided into four sensor element groups  40   a  (a first sensor element group which includes the ultrasonic transducers Nos. 1-47 and 314-360),  40   b  (a second sensor element group which includes the ultrasonic transducers Nos. 44-137),  40   c  (a third sensor element group which includes the ultrasonic transducers Nos. 134-227) and  40   d  (a fourth sensor element group which includes the ultrasonic transducers Nos. 224-317). The four sensor element groups  40   a - 40   d  divide the outer periphery of the cylindrical substrate  13  into four approximately equal portions. 
     There are 94 ultrasonic transducers  12  in each sensor element group. At the boundary of the first sensor element group  40   a  and the second sensor element group  40   b , the ultrasonic transducers  12  Nos. 44-47 are contained in both element groups. At the boundary of the second sensor element group  40   b  and the third sensor element group  40   c , the ultrasonic transducers Nos. 134-137 are contained in both sensor element groups. At the boundary of the third sensor element group  40   c  and the fourth sensor element group  40   d , the ultrasonic transducers Nos. 224-227 are contained in both element groups. At the boundary of the fourth sensor element group  40   d  and the first sensor element group  40   a , the ultrasonic transducers Nos. 314-317 are contained in both element groups. Note that Nos. 1-360 are the numbers assigned to each of the ultrasonic transducers in a clockwise direction for the sake of convenience. 
     In  FIG. 1 , a control line  19  is connected to the MPa  17 . The control line  19  receives an element group selection signal from a CPU  20  (which will be described later) of the ultrasonic observation apparatus  11 . According to the sensor element group selection signal, the MPa  17  switches the signal of 360 channels, which is transmitted from the first to fourth sensor element groups  40   a - 40   d  through the first signal lines  16 , to that of 94 channels in the selected sensor element group. One end of each of 94 second signal lines  18  is connected to the MPa  17 . The other end of each of the 94 second signal lines  18  is connected to the ultrasonic observation apparatus  11  through the second connector  15 . 
     As shown in  FIG. 3 , the MPa  17  is constructed of a decoder  50 , and first to fourth switches (SWa-SWd)  51   a - 51   d  which are constituted of FET and the like. The decoder  50  receives and decodes the sensor element group selection signal of two-bit sent from the CPU  20  of the ultrasonic observation apparatus  11  through the control line  19 . 
     The signals from the ultrasonic transducers  12  of the first to fourth sensor element groups  40   a - 40   d  are respectively input to the corresponding switches (SWa-SWd)  51   a - 51   d  through the first signal lines  16 . The overlapping transducers  12  at the boundaries between the first to the fourth sensor element groups  40   a - 40   d  are connected to each of the corresponding switches (SWa-SWd)  51   a - 51   d.    
     The first to the fourth switches (SWa-SWd)  51   a - 51   d  are switched between on and off according to the sensor element group selection signals decoded in the decoder  50 . To be more specific, for instance, when the sensor element group selection signal is “00”, the first sensor element group  40   a  is selected. At that time, the SWa  51   a  is turned on while the SWb-SWd  51   b - 51   d  are turned off. When the sensor element group selection signal is “01”, the second sensor element group  40   b  is selected. At that time, the SWb  51   b  is turned on while the SWa  51   a , SWc  51   c  and SWd  51   d  are turned off. Further, when the sensor element group selection signal is “10”, the third sensor element group  40   c  is selected. At that time, the SWc  51   c  is turned on while the SWa  51   a , SWb  51   b  and SWd  51   d  are turned off. When the sensor element group selection signal is “11”, the fourth sensor element group  40   d  is selected. At that time, the SWd  51   d  is turned on while the SWa-SWc  51   a - 51   c  are turned off. 
     In  FIG. 1 , the ultrasonic observation apparatus  11  is thoroughly controlled by the CPU  20 . A scan controller  21  is connected to the CPU  20 . The scan controller  21  is connected to a multiplexer (MPb)  22 , the transmitter  23  and a receiver  24 , and transmits a reference pulse to each of the above sections to control the operation. An ultrasonic probe of a convex scan type with 94 channels has 94 ultrasonic transducers disposed in a sector shape on its tip (not shown). In a connector section of the ultrasonic probe of the convex scan type, an insertion detector/probe type identifier, which has the same function as an insertion detector/probe type identifier  31 , is provided, which will be described later. 
     The MPb  22  selectively switches the signals of five channels out of 94 channels which are input and output through the second connector section  15 . The drive signal of five channels is input from the transmitter  23  to the MPb  22 , and the MPb  22  outputs the echo signal of five channels to the receiver  24 . 
     The MPb  22  simultaneously drives the five selected ultrasonic transducers  12  as one block, out of one of the sensor element group selected by the MPa  17 , under the control of the scan controller  21 . Further, as shown in  FIG. 2 , the MPb  22  selectively switches the ultrasonic transducer  12 , which receives and transmits the drive signal and the echo signal, by shifting at least one ultrasonic transducer  12  to be driven in the clockwise direction every time the drive signal and the echo signal are transmitted and received. 
     Under the control of the scan controller  21 , the transmitter  23  transmits the drive signal (a voltage pulse with five channels for driving the ultrasonic transducer  12 ) to the ultrasonic transducer  12  selected by the MPb  22 . 
     Under the control of the scan controller  21 , the receiver  24  receives the echo signal (five channels) reflected from within the living organism, which is obtained by the ultrasonic transducers  12  selected by the MPb  22 , and performs Sensitivity Time Control (STC) process to the received echo signal. In the STC, the sensitivity is adjusted according to the time which corresponds to a propagation distance (depth) of the ultrasound. The respective timings of the transmission and the reception of the transmitter  23  and the receiver  24  are switched by the scan controller  21 . 
     The echo signal received by the receiver  24  is input to a beamformer (BF)  25 . The echo signal of five channels is delayed by the BF  25  for a predetermined time to be co-phased, and added. 
     The echo signal, which is added in the BF  25 , is digitalized and then stored in a memory  26 . A digital scan converter (DSC)  27  reads the digital signal from the memory  26  under the control of the CPU  20 , and converts the read digital signal into a television signal of a NTSC format. A D/A converter  28  converts the signal, which has been converted into the NTSC format by the DSC  27 , into the analog signal again. A monitor  29  displays the analog signal converted by the D/A converter  28  as an ultrasonic image. 
     In addition to the above mentioned scan controller  21  and the DSC  27 , an operation unit  30  and a serial signal line  32 , through which a notification signal from the insertion detector/probe type identifier  31  provided in the first connector  14  of the ultrasonic probe  12  is transmitted, are connected to the CPU  20 . The operation unit  30  is constructed of an operation panel in which various operation buttons are disposed, for instance. The CPU  20  controls the operation of each section according to the signals input from the operation unit  30 . 
     An identification code, which indicates that the ultrasonic probe  12  is of the radial scan type, is stored in the insertion detector/probe type identifier  31 . The insertion detector/probe type identifier  31  transmits the identification code to the CPU  20  by a serial communication through the serial signal line  32 . Further, the CPU  20  detects the insertion of the ultrasonic probe by receiving the identification code. 
     When the CPU  20  receives the insertion detection signal and the identification signal from the insertion detector/probe type identifier  31 , and identifies that the ultrasonic probe of the convex scan type with the 94 channels is connected, the CPU  20  controls the operation of the MPb  22  through the scan controller  21  without transmitting the sensor element group selection signal to the MPa  17  (a first mode). When the CPU  20  identifies that the ultrasonic probe  10  of the radial scan type with the 360 channels is connected, the CPU  20  transmits the sensor element group selection signal to MPa  17  through the control line  19  and controls the operation of the MPb  22  through the scan controller  21  (a second mode). 
     Next, the operation of the ultrasonic diagnosing system  2  of the above configuration is described with reference to flowcharts in  FIGS. 4 and 5 . In  FIG. 4 , when the CPU  20  identifies that the ultrasonic probe of the convex scan type with the 94 channels is connected to the ultrasonic observation apparatus  11 , the freeze is released by operating the operation unit  30 . Thereafter, the drive signal of five channels is transmitted from the transmitter  23  under the control of the scan controller  21 . 
     The drive signal is transmitted from the transmitter  23  to the desired block of the ultrasonic transducers selected by the MPb  22 , through the first and second connectors  14  and  15 . The ultrasonic transducers are driven by the drive signal so that the ultrasound is emitted to the living organism. 
     After the drive signal has been transmitted, the scan controller  21  switches from the transmission of the transmitter  23  to the reception of the receiver  24 . Thereby, the echo signal reflected from within the living organism, which is obtained by the ultrasonic transducers, is input to the receiver  24  through the first and second connectors  14 ,  15  and the MPb  22 . 
     The receiver  24  performs the STC (Sensitivity Time Control) process to the input echo signal. Then, the echo signal is added by the BF  25 , and digitalized. The digital signal is stored in the memory  26 . Thereafter, the above process is repeated through the last block while the MPb  22  shifts the ultrasonic transducer, which is to be driven, one by one under the control of the scan controller  21 . 
     When the scanning by the 94 ultrasonic transducers is completed, the DSC  27  reads the digital echo signal stored in the memory  26  and converts into the NTSC format. The signal converted into the NTSC format is re-converted into the analog signal by the D/A converter  28  and displayed as the ultrasonic image on the monitor  29 . The above sequential process is continued until the operation unit  30  is operated to issue a command to freeze. 
     When the CPU  20  identifies that the ultrasonic probe  12  of the radial scan type with the 360 channels is connected to the ultrasonic observation apparatus  11 , as shown in  FIG. 5 , after the freeze is released by operating the operation unit  30 , the transmitter  23  transmits the drive signal of five channels under the control of the scan controller  21 . 
     The drive signal from the transmitter  23  is transmitted to the desired block of the ultrasonic transducers  12  selected by the MPb  22  from one of the sensor element groups  40   a - 40   d  selected by the MPa  17  according to the sensor element group selection signal sent from the CPU  20  through the control line  19 . The ultrasonic transducer  12  is driven by the drive signal and thereby the ultrasound is emitted to the living organism. 
     After the drive signal has been transmitted, the scan controller  21  switches from the transmission of the transmitter  23  to the reception of the receiver  24 . The echo signal reflected from within the living organism, which is obtained by the ultrasonic transducers, is input to the receiver  24  through the first and second connectors  14  and  15 , and the MPb  22 . 
     In the receiver  24 , the STC process is performed to the input echo signal. Then, the signal is added by the BF  25 , digitalized, and stored in the memory  26 . Thereafter, under the control of the scan controller  21 , the above process is repeated through the last block, while the MPb  22  shifts the ultrasonic transducer to be driven one by one. 
     In the MPa  17 , the sensor element group selection signal transmitted from the CPU  20  is decoded by the decoder  50 . The sensor element group selection signal “00” is sent to turn on the SWa  51   a  and turn off the SWb-SWd  51   b - 51   d  in the MPa  17 . Thereby, the first sensor element group  40   a  is selected. In that state, the above process is performed through the last block of the first sensor element group  40   a . Thereafter, the sensor element group selection signal “01” is transmitted to turn on the SWb  51   b  and turn off the SWa  51   a , SWc  51   c  and SWd  51   d  in the MPa  17 . Thereby, the second sensor element group  40   b  is selected and the above process is performed in the second sensor element group  40   b . Thereafter, the sensor element group selection signal “10” and “11” are transmitted in this order so that the third and the fourth sensor element groups  40   c  and  40   d  are selected sequentially and the above process is respectively performed in the third and fourth sensor element groups  40   c  and  40   d.    
     When the scanning by the 360 ultrasonic transducers  12  is completed, the digital echo signal stored in the memory  26  is read by the DSC  27  and converted into the NTSC format in the same manner as to when the ultrasonic transducer of the convex scan type is connected. Thereafter, the signal is reconverted into the analog signal in the D/A converter  28 , and displayed on the monitor  29  as the ultrasonic image. The above process is repeated until the operation unit  30  is operated to issue the command to freeze. 
     As described above, since the 360 ultrasonic transducers are divided into four sensor element groups  40   a - 40   d , and the MPa  17 , which selectively connects the 94 first signal lines  16  out of the 360 first signal lines  16  to the second signal lines  18  according to the selected sensor element group, is disposed, the ultrasonic probe  10  of the radial scan type which can be connected to the ultrasonic observation apparatus  11  for the conventional ultrasonic probe of the convex scan type, and the ultrasonic diagnosing system  2  using the ultrasonic probe  10  are provided at a low cost. 
     Further, since the MPa  17  is provided in the first connector  14 , it is relatively easy to manufacture the ultrasonic probe, which is connectable to the ultrasonic observation apparatus  11  of the convex scan type, by utilizing the structure of the conventional ultrasonic probe of the radial scan type. 
     In  FIG. 6 , an ultrasonic diagnosing system  60  is constructed of an ultrasonic probe  61  of the radial scan type and an ultrasonic observation apparatus  62 . The ultrasonic probe  61  has the same configuration as the ultrasonic probe  10  in  FIG. 1  except that the ultrasonic probe  61  does not have the MPa  17  so that 360 first signal lines  63  from the 360 ultrasonic transducers  12  are directly connected to a first connector  64 . 
     A second connector  65  of the ultrasonic observation apparatus  62  is provided with a multiplexer (MPc)  66  which has the same configuration as the MPa  17  in  FIG. 3 . As with the MPa  17 , the MPc  66  selectively switches the 94 first signal lines  63  of the first signal lines  63  connected through the first connector  64 , and respectively connects to 94 second signal lines  67  according to the selected sensor element group among the sensor element groups  40   a - 40   d.    
     The first connector  64  is formed with 360 pins which respectively correspond to 360 channels, for instance. To be compatible with both the 360 channels and 94 channels, the second connector  65  is formed with 360 pins holes, for instance. When the ultrasonic probe of the convex scan type with the 94 channels is inserted into the second connector  65 , 94 pins are inserted into the pin holes which correspond to the first sensor element group  40   a.    
     Upon receiving the insertion detection signal and the identification code from the insertion detector/probe type identifier  31 , and identifying that the ultrasonic probe of the convex scan type with the 94 channels is connected, the CPU  20  controls the MPc  66  to fix the sensor element group selection signal to “00” to constantly select the first sensor element group  40   a , and also controls the action of MPb  22  through the scan controller  21  (a first mode). When the CPU  20  identifies that the ultrasonic probe  10  of the radial scan type with the 360 channels is connected, the CPU  20  transmits the sensor element group selection signal to the MPc  66  through the control line  19  and also controls the action of the MPb  22  through the scan controller  21  (a second mode). Further, other configuration and the operation of the ultrasonic diagnosing system  60  are similar to the ultrasonic diagnosing system  2  shown in  FIG. 1 , so that the same numeral is assigned to the similar component, and the descriptions and illustrations are omitted. 
     As shown above in the second embodiment, since the MPc  66 , which divides the 360 ultrasonic transducers  12  into four sensor element groups  40   a - 40   d  and selectively switches and connects  94  first signal lines  63  out of 360 first signal lines  63  to the second signal lines  67  according to the first to fourth sensor element groups  40   a - 40   d , is disposed in the ultrasonic observation apparatus  62 , the ultrasonic observation apparatus  62  of the convex scan type, to which the ultrasonic probe  61  of the radial scan type can also be applicable, and the ultrasonic diagnosing system  60  using the ultrasonic observation apparatus  62  are provided at low cost. 
     Further, since the MPc  66  is provided in the second connector  65 , the ultrasonic observation apparatus, which is capable of connecting the ultrasonic probe of the radial scan type, can be manufactured with relative ease by modifying the conventional ultrasonic observation apparatus of the convex scan type. 
     In  FIG. 7 , an ultrasonic diagnosing system  70  is constructed of an ultrasonic probe  71  of the radial scan type and an ultrasonic observation apparatus  72 . The ultrasonic probe  71  has the similar configuration as the ultrasonic probe  61  in  FIG. 6 , and 360 first signal lines  73  from the 360 ultrasonic transducers  12  are directly connected to a first connector  74 . 
     A multiplexer (MPd)  75  is disposed in the ultrasonic observation apparatus  72 . The MPd  75  selectively switches five first signal lines  73  connected through the first and second connectors  74  and  76  according to the first to fourth sensor element groups  40   a - 40   d  and connects the five first signal lines  73  to the transmitter  23  and the receiver  24  through five second signal lines  77 . 
     As shown in  FIG. 8 , the MPd  75  is constructed of a decoder  80 , which receives and decodes the sensor element group selection signal of two-bit sent from the CPU  20  through the control line  19 , and first to fourth switches (SWa-SWd)  81   a - 81   d.    
     The SWa-SWd  81   a - 81   d  selectively switch the first to fourth sensor element groups  40   a - 40   d  according to the sensor element group selection signal decoded in the decoder  80 , and simultaneously drive the five ultrasonic transducers  12  as one block in the selected sensor element group under the control of the scan controller  21 . Further, the MPd  75  selectively switches the ultrasonic transducer  12 , which transmits and receives the drive signal and the echo signal, by shifting at least one ultrasonic transducer  12  (see  FIG. 2 ) to be driven in the clockwise direction every time the drive signal and the echo signal are transmitted and received. That is, the MPd  75  integrates the functions of the MPa  17  and MPb  22 . 
     The MPd  75  is constituted of a programmable logic circuit, which is capable of reprogramming an arbitrary program, such as FPGA (Field Programmable Gate Array) and the like. The CPU  20  detects the number of channels being used in the ultrasonic probe according to the identification code from the insertion detector/probe type identifier  31 , and reprograms the logic circuit of the MPd  75  based on the detected results. 
     Similar to the second embodiment, for instance, 360 pins corresponding to 360 channels are formed in the first connector  74 . The second connector  74  has 360 pin holes, for instance, to be compatible with 360 channels and 94 channels. When the ultrasonic probe of the convex scan type with 94 channels is inserted, 94 pins are inserted in the pin holes which correspond to the first sensor element group  40   a.    
     Upon receiving the insertion detection signal and the identification code from the insertion detector/probe type identifier  31 , and identifying that the ultrasonic probe of the convex scan type with the 94 channels is connected, the CPU  20 , in the same manner as the second embodiment, controls the MPd  75  to fix the sensor element group selection signal to “00” to constantly select the first sensor element group  40   a , and also controls the action of MPd  75  through the scan controller  21  (a first mode). When the CPU  20  identifies that the ultrasonic probe  10  of the radial scan type with the 360 channels is connected, the CPU  20  transmits the sensor element group selection signal to the MPd  75  through the control line  19  and also controls the action of the MPd  75  through the scan controller  21  (a second mode). Further, other configuration and the operation of the ultrasonic diagnosing system  70  are similar to the ultrasonic diagnosing system  2  shown in  FIG. 1 , so that the same numeral is assigned to the similar component, and the descriptions and illustrations are omitted. 
     As shown above in the third embodiment, since the MPd  75 , which divides the 360 ultrasonic transducers  12  into four sensor element groups  40   a - 40   d  and selectively switches and connects five of 360 first signal lines  73  to the transmitter  23  and the receiver  24  through the five second signal lines  77  according to the first to fourth sensor element groups  40   a - 40   d , is disposed in the ultrasonic observation apparatus  72 , the ultrasonic observation apparatus  72 , to which the ultrasonic probes of the convex scan type and the radial scan type are applicable, and the ultrasonic diagnosing system  70  using the ultrasonic observation apparatus  72  are provided at low cost. 
     Since the MPd  75  is constituted of a programmable logic circuit, which is capable of reprogramming an arbitrary program, such as FPGA (Field Programmable Gate Array) and the like, the ultrasonic probe of the convex scan type with the number of channels other than 94 can also be connected. 
     Further, the number of ultrasonic transducers  12 , the number of ultrasonic transducers  12  included in each of the first to fourth sensor element groups  40   a - 40   d , the number of the drive signals transmitted from the transmitter  23  and the number of the echo signals received by the receiver  24  are not limited in those described in the above embodiments. Each number can be properly changed according to a specification of the ultrasonic diagnosing system. 
     In the above first embodiment, the MPb  22  is disposed between the second connector  15 , and the transmitter  23  and the receiver  24 . In the above second embodiment, the MPb  22  is disposed between the second connector  65 , and the transmitter  23  and the receiver  24 . However, it is also possible to dispose the MPb  22  between the receiver  24  and the BF  25 . 
     In the second and third embodiments described above, the second connectors  65  and  76 , which are compatible with both 360 channels and 94 channels, are respectively disposed in the ultrasonic observation apparatuses  62  and  72 . However, it is also possible to provide separate connectors for 360 channels and 94 channels. 
     In the above embodiment, the ultrasonic probe, which has the ultrasonic transducers on the outer periphery in one line, is described as an example. However, the present invention can be applied to the ultrasonic probe which has 360 ultrasonic transducers disposed on the outer periphery in plural lines. In that case, the ultrasonic transducers are divided into four sensor element groups along an axial direction of the sheath as in the same manner as the above embodiments. 
     In the above embodiment, only ultrasonic transducers are provided in the ultrasonic probe. However, it is also possible to integrally provide an endoscope in the ultrasonic probe. 
     Although the present invention has been described with respect to the preferred embodiment, the present invention is not to be limited to the above embodiment but, on the contrary, various modifications will be possible to those skilled in the art without departing from the scope of claims appended hereto.