Abstract:
An ultrasonic probe includes: a transducer unit including a plurality of transducers transmitting/receiving an ultrasonic wave; a transducer holding frame; an acoustic window formed from a material having an ultrasonic transmission property, the acoustic window forming a first space including the transducer unit in an inner part; a driving unit; a driving unit holding frame which holds the driving unit and forms a second space including an output shaft of the driving unit in an inner part; a pipe including a hollow portion with which connects the first space and the second space; a force transmission unit; and a housing including, in an inner part, the transducer unit, the transducer holding frame, the acoustic window, the driving unit, the driving unit holding frame, the pipe, and the force transmission unit, wherein the first space, the hollow portion of the pipe, and the second space are filled with coupling liquid.

Description:
[0001]    The entire disclosure of Japanese Patent Application No. 2014-224294 filed on Nov. 4, 2014 including description, claims, drawings, and abstract are incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an ultrasonic probe which is inserted into a body cavity and which performs scanning with an ultrasonic transducer automatically. 
         [0004]    2. Description of the Related Art 
         [0005]    Recently, an ultrasonic diagnostic device which includes an ultrasonic probe and which images the echo signal has been widely used, the ultrasonic probe being inserted into a body cavity such as a rectum or a vagina and acquiring an echo signal which is a reflection wave of an ultrasonic wave transmitted into the body cavity. 
         [0006]    As an ultrasonic probe which is inserted into a body cavity in such a manner and which performs scanning with an ultrasonic transducer automatically, what performs scanning with an ultrasonic wave by making a transducer unit, which includes a plurality of transducers to transmit/receive an ultrasonic wave and which is arranged at a leading end part, perform an oscillating movement by drive force (JP 10-179588 A and JP 2000-70268 A) is generally used. 
         [0007]    It is desired to further improve operability of an ultrasonic probe for a body cavity. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has been made in view of the forgoing and an object thereof is to provide an ultrasonic probe for a body cavity with which probe operability is improved, for example, by reducing weight. 
         [0009]    To achieve the abovementioned object, according to an aspect, an ultrasonic probe reflecting one aspect of the present invention comprises: a transducer unit including a plurality of transducers configured to transmit/receive an ultrasonic wave; a transducer holding frame which holds the transducer unit in an oscillatable manner; an acoustic window which is formed from a material having an ultrasonic transmission property, provided in a front part of an ultrasonic wave transmission/reception surface of the transducer unit, and fixed to the transducer holding frame in a sealed manner, the acoustic window forming a first space including the transducer unit in an inner part; a driving unit configured to generate drive force to oscillate the transducer unit; a driving unit holding frame which holds the driving unit and forms a second space including an output shaft of the driving unit in an inner part; a pipe including a hollow portion with which connects the first space and the second space; a force transmission unit which is put through the hollow portion of the pipe and which is configured to oscillate the transducer unit by transmitting the drive force of the driving unit; and a housing including, in an inner part, the transducer unit, the transducer holding frame, the acoustic window, the driving unit, the driving unit holding frame, the pipe, and the force transmission unit, wherein the first space, the hollow portion of the pipe, and the second space are filled with coupling liquid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The above and other objects, advantages and features of the present invention will become more fully understood from the detailed description given hereinbelow and the appended drawings which are given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, and wherein: 
           [0011]      FIG. 1  is an upper sectional view of an ultrasonic probe according to an embodiment of the present invention; 
           [0012]      FIG. 2  is a front sectional view of the ultrasonic probe according to the embodiment of the present invention; 
           [0013]      FIG. 3  is a partial perspective view of the ultrasonic probe according to the embodiment of the present invention; 
           [0014]      FIG. 4A  and  FIG. 4B  are views for describing a method of fixing a wire; 
           [0015]      FIG. 5  is a partial perspective view of the ultrasonic probe according to the embodiment of the present invention; and 
           [0016]      FIG. 6  is a partial perspective view of the ultrasonic probe according to the embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.  FIG. 1  and  FIG. 2  are respectively an upper sectional view and a front perspective view of an ultrasonic probe according to an embodiment of the present invention. As illustrated in  FIG. 1  and  FIG. 2 , a housing  10  of an ultrasonic probe  1  includes a grip part  11  gripped by an operator in the outside of a body cavity and an insertion part  12  inserted into the body cavity. 
         [0018]    In an inner part of a leading end part  13  of the insertion part  12 , a transducer holding frame  20  is attached in a fixed manner. The transducer holding frame  20  is formed from a material such as aluminum or plastic in a hollow shape with an opening at one end. In an outer peripheral part of a side surface  21 , the transducer holding frame  20  is fixed to an inner periphery of an end part of the insertion part  12  of the housing  10 . On a bottom surface  22  of the transducer holding frame  20 , holes  23   a  and  23   b  (see  FIG. 5 ) through which flexible printed circuits (FPC)  70   a  and  70   b  are put and holes  24   a  and  24   b  to which pipes  130   a  and  130   b  are attached are provided. 
         [0019]    To the transducer holding frame  20 , an oscillation shaft  30  is attached in a rotatable manner. The oscillation shaft  30  is formed in a cylindrical shape from a material such as stainless steel. To the oscillation shaft  30 , a driven pulley  40  and a transducer unit  50  are attached in a fixed manner. 
         [0020]    The driven pulley  40  oscillates the oscillation shaft  30  along with a movement of a wire (force transmission unit)  140  due to driving of a motor (driving unit)  120 . Note that a detail of a method of arranging the wire  140  to the driven pulley  40  will be described later. 
         [0021]    To the transducer unit  50 , a plurality of transducers (piezoelectric oscillation element) to transmit/receive an ultrasonic wave is arranged. Each transducer converts an electric signal into an ultrasonic wave and emits the ultrasonic wave to an inner side of a body of a subject. Then, each transducer detects the ultrasonic wave reflected in the inner side of the body (reflection wave) and converts the ultrasonic wave into an electric signal. Along with oscillation of the oscillation shaft  30 , the transducer unit  50  oscillates around a central axis of the oscillation shaft  30  extended in a direction orthogonal to an ultrasonic wave transmission/reception surface  51  (up/down direction on plane of paper in  FIG. 2 ). By oscillating the transducer unit  50 , it is possible to move an ultrasonic wave forming surface and to form a three-dimensional ultrasonic image. 
         [0022]    In a front part of the ultrasonic wave transmission/reception surface  51  of the transducer unit  50 , an acoustic window  60  is attached. The acoustic window  60  is formed in a dome shape from a material having an ultrasonic transmission property and is fixed to the transducer holding frame  20  in a sealed manner to cover an opening  25  of the transducer holding frame  20 . As a result, the transducer unit  50  is arranged in a space formed by the acoustic window  60  and the transducer holding frame  20  (first space). 
         [0023]    The space formed by the acoustic window  60  and the transducer holding frame  20  (first space) is filled with coupling liquid to improve propagation capability of an ultrasonic wave and to guide the ultrasonic wave to a body surface with a little attenuation. 
         [0024]    To each transducer arranged in the transducer unit  50 , the flexible printed circuits  70   a  and  70   b  are connected. The flexible printed circuits  70   a  and  70   b  are pulled from the holes  23   a  and  23   b  provided in the bottom surface  22  of the transducer holding frame  20 . Each of the flexible printed circuits  70   a  and  70   b  transmits, to each transducer, an electric signal output from a diagnosis device main body (not illustrated) and transmits, to the diagnosis device main body, an electric signal output from each transducer. Note that a detail of a method of sealing the holes  23   a  and  23   b  will be described later. 
         [0025]    Further, into the holes  24   a  and  24   b  provided in the bottom surface  22  of the transducer holding frame  20 , one end parts of the pipes  130   a  and  130   b  are respectively inserted. In this state, the pipes  130   a  and  130   b  are welded to the transducer holding frame  20  and the holes  24   a  and  24   b  are sealed. Note that the space formed by the acoustic window  60  and the transducer holding frame  20  are in communication with the hollow portions of the pipes  130   a  and  130   b.  Thus, the hollow portions of the pipes  130   a  and  130   b  are also filled with the coupling liquid. 
         [0026]    In an inner part of the grip part  11  of the housing  10 , a casing (driving unit holding frame)  90  is attached in a fixed manner. The casing  90  is formed, for example, in a hollow shape from a metal or plastic material. In a first surface  91  of the casing  90  which surface faces the transducer holding frame  20 , holes  92   a  and  92   b  to which the pipes  130   a  and  130   b  are attached are provided. In a second surface  93  of the casing  90  which surface faces the transducer holding frame  20 , a hole  94  through which an output shaft  121  of the motor  120  is inserted into an inner part is provided. 
         [0027]    To the second surface  93  of the casing  90 , the motor  120  is attached in a fixed manner in a state in which the output shaft  121  of the motor  120  is inserted into the hole  94 . The motor  120  functions as a driving mechanism to oscillate the transducer unit  50 . An oil seal  122  is fitted between the hole  94  and the output shaft  121  of the motor  120 . Accordingly, the hole  94  is sealed. 
         [0028]    Further, into the holes  92   a  and  92   b  provided in the first surface  91  of the casing  90 , the other end parts of the pipes  130   a  and  130   b  are respectively inserted. In this state, the pipes  130   a  and  130   b  are welded to the casing  90  and the holes  92   a  and  92   b  are sealed. Note that an inner space of the casing  90  is in communication with the hollow portions of the pipes  130   a  and  130   b.  Accordingly, the inner space of the casing  90  is also filled with the coupling liquid. 
         [0029]    In the inner space of the casing  90  (second space), a driving pulley unit  100  and intermediate pulleys  110   a  and  110   b  are housed. 
         [0030]    The driving pulley unit  100  is coaxially attached to a leasing end of the output shaft  121  of the motor  120  in a fixed manner. In the driving pulley unit  100 , driving pulleys  101   a  and  101   b  are formed. A rotational axis each of the driving pulleys  101   a  and  101   b  is orthogonal to a rotational axis of the driven pulley  40 . Note that a detail of the driving pulley unit  100  will be described later. 
         [0031]    The intermediate pulleys  110   a  and  110   b  are attached to the casing  90 , respectively through the attachment shafts  111   a  and  111   b,  in a manner rotatable around the attachment shafts  111   a  and  111   b  or rotatable along with the attachment shafts  111   a  and  111   b.  A rotational axis of each of the intermediate pulleys  110   a  and  110   b  is orthogonal to the rotational axis of the driven pulley  40  and the rotational axis of each of the driving pulleys  101   a  and  101   b.  In an outer periphery of each of the intermediate pulleys  110   a  and  110   b , a wire groove to arrange the wire  140  is formed. 
         [0032]    The pipes  130   a  and  130   b  are formed from a metal material. One end parts of the pipes  130   a  and  130   b  are respectively inserted into the holes  24   a  and  24   b  and fixed to the transducer holding frame  20  and the other end parts thereof are respectively inserted into the holes  92   a  and  92   b  and fixed to the casing  90 . The hollow portions of the pipes  130   a  and  130   b  are in communication with the space formed by the acoustic window  60  and the transducer holding frame  20  and the inner space of the casing  90 . Thus, the hollow portions of the pipes  130   a  and  130   b  and the inner space of the casing  90  are also filled with the coupling liquid. 
         [0033]    The wire  140  is serially arranged in the driving pulley  101   a  and the intermediate pulley  110   a  while one end part thereof is fixed to the driving pulley  101   a.  Then, the wire  140  is put through the pipe  130   a,  arranged in the driven pulley  40 , and put through the hole  44  (see  FIG. 3 ) of the driven pulley  40 . Further, the wire  140  put though the hole  44  is serially arranged in the driven pulley  40 , put through the pipe  130   b , and arranged in the intermediate pulley  110   a  and the driving pulley  101   b.  Then, the other end part of the wire  140  is fixed to the driving pulley  101   b.    
         [0034]    Then, a detail of a method of arranging the wire  140  to the driven pulley  40  will be described with reference to  FIG. 3 . As illustrated in  FIG. 3 , in an outer peripheral surface  41  of the driven pulley  40 , two wire grooves  42  and  43  are provided and the hole  44  to connect the wire groove  42  and the wire groove  43  is formed. To the driven pulley  40 , the wire  140  arranged in the wire groove  42  is arranged doubly in such a manner that the wire  140  is also arranged in the wire groove  43  through the hole  44 . The wire  140  is fixed to the driven pulley  40 , in a part of the hole  44 , with a pin member or the like. 
         [0035]    As illustrated in  FIG. 4A , in a related art, a wire fixing part to fix a wire is generally provided in a groove of a driven pulley as a method of fixing a wire. In this case, since there is the wire fixing part, it has been difficult to rotate the driven pulley and a transducer unit for equal to or larger than 180°. 
         [0036]    On the other hand, as illustrated in  FIG. 4B , in an embodiment of the present invention, it is not necessary to provide a wire fixing part unlike the related art. Instead, a wire is arranged doubly. Thus, an oscillation angle of each of the driven pulley and the transducer unit can be equal to or larger than 180°. 
         [0037]    Next, a detail of a method of sealing the holes  23   a  and  23   b  will be described with reference to  FIG. 5 . As illustrated in  FIG. 5 , holding members  80   a  and  80   b  which respectively hold the flexible printed circuits  70   a  and  70   b  are respectively inserted into the holes  23   a  and  23   b.  In this state, an adhesive is injected into the holes  23   a  and  23   b  and the holes  23   a  and  23   b  are sealed. 
         [0038]    Accordingly, in a region in which a movement can be performed due to the oscillation of the transducer unit  50 , the flexible printed circuits  70   a  and  70   b  are fixed to the transducer holding frame  20  without attachment of an adhesive. 
         [0039]    Next, a detail of the driving pulley unit  100  will be described with reference to  FIG. 6 . As illustrated in  FIG. 6 , in the driving pulleys  101   a  and  101   b,  wire grooves  102   a  and  102   b  to which the wire  140  is arranged are provided. Both end parts of the wire  140  are respectively fixed to the driving pulleys  101   a  and  101   b  by a screw lock in a wire end fixing part  103  while being arranged in the wire grooves  102   a  and  102   b.    
         [0040]    Further, to the driving pulley unit  100 , coil springs  104   a  and  104   b  are attached. It is possible to apply tension to the wire  140  by biasing the coil springs  104   a  and  104   b  and it is possible to adjust the tension of the wire  140  by a degree of the biasing. Accordingly, it is possible to apply necessary tension to the wire  140  without providing a new tensioner which generates tension and to reduce a size and weight of the driving pulley unit. Further, accordingly, the wire  140  can oscillate the transducer unit  50  according to an amount of rotation of the output shaft  121  along with the driving of the motor  120 . 
         [0041]    Next, operation of the ultrasonic probe  1  will be described. First, an operator holds the grip part  11  and inserts the insertion part  12  into a body cavity. 
         [0042]    Then, the operator operates an operation unit (not illustrated) of the diagnosis device main body and gives an instruction for forming an ultrasonic image. When the instruction is received, a control unit (not illustrated) of the diagnosis device main body oscillates and rotates the output shaft  121  (driving pulley unit  100 ) of the motor  120 . Accordingly, a rotational movement of the driving pulley unit  100  is transmitted by the wire  140  to the driven pulley  40 , whereby the transducer unit  50  can be oscillated and rotated around a rotational axis and the ultrasonic wave forming surface can be moved. 
         [0043]    Further, the control unit of the diagnosis device main body transmits an electric signal to each transducer through the flexible printed circuits  70   a  and  70   b.  Along with the oscillation of the transducer unit  50 , each transducer converts the received electric signal into an ultrasonic wave and emits the ultrasonic wave to an inner side of a body of a subject. Then, each transducer detects the ultrasonic wave reflected on the inner side of the body (reflection wave), converts the ultrasonic wave into an electric signal, and transmits the electric signal to the control unit of the diagnosis device main body through the flexible printed circuits  70   a  and  70   b.  Accordingly, the control unit can form a three-dimensional ultrasonic image and can display the ultrasonic image on a screen. 
         [0044]    As described above, according to an embodiment of the present invention, since the transducer holding frame  20  and the casing  90  are connected by the pipes  130   a  and  130   b  and the wire  140  is put through the pipes  130   a  and  130   b,  only the inside of each of the pipes  130   a  and  130   b  needs to be filled with coupling liquid in the insertion part  12  of the housing  10 . Thus, it is possible to reduce an amount of the coupling liquid and to reduce weight of the ultrasonic probe  1 . 
         [0045]    Further, according to an embodiment of the present invention, each of the metal pipes  130   a  and  130   b  has predetermined intensity. Thus, it is possible to form the insertion part  12  of the housing  10  from a light material such as plastic and to reduce weight of the ultrasonic probe  1 . 
         [0046]    Further, according to an embodiment of the present invention, the flexible printed circuits  70   a  and  70   b  are arranged outside of the pipes  130   a  and  130   b.  Thus, it is possible to reduce a part, which is in contact with coupling liquid, of each of the flexible printed circuits  70   a  and  70   b  and to prevent the flexible printed circuits  70   a  and  70   b  from being damaged due to a contact with the wire  140 . 
         [0047]    Further, according to an embodiment of the present invention, the two wire grooves  42  and  43  and the hole  44  to connect the two are formed in the driven pulley  40  and the wire  140  is doubly arranged in the driven pulley  40  in such a manner that the wire  140  arranged in the wire groove  42  is put through the hole  44  and is arranged in the wire groove  43 . Thus, an oscillation angle of the transducer unit  50  can be increased compared to a related art. 
         [0048]    Note that in the above-described embodiment, a case where there are two pipes has been described but the present invention is not limited thereto. There may be one pipe. 
         [0049]    An embodiment of the present invention can be used for an ultrasonic probe which is inserted into a body cavity and which performs scanning with an ultrasonic transducer automatically. 
         [0050]    Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustrated and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by terms of the appended claims.