JP2014198133A - Ultrasound measurement device and ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic probe capable of fully interposing an acoustic coupling material between the ultrasonic probe and an object even if a shape relative to the object varies.SOLUTION: An acoustic matching body of an ultrasonic probe forms a transmission surface 26. Ultrasonic transducer elements are coupled to the acoustic matching body. For ultrasonic measurement, the transmission surface 26 is brought into contact with an object BD1 or BD2, for example, a body surface. For the contact, an acoustic coupling material such as water is fed to a space between the object BD1 or BD2 and transmission surface 26 through a feeding port. The distance between the transmission surface 26 and object BD1 or BD2 varies depending on the shape of the object BD1 or BD2. When the acoustic coupling material is fed according to a change in the distance, an ultrasound measurement device can fully interpose the acoustic coupling material between the transmission surface and object.

Description

  The present invention relates to an ultrasonic measurement device, an ultrasonic probe, and the like.

  As disclosed in Patent Document 1, for example, an ultrasonic flaw detection method for detecting an internal defect in steel is generally known. When performing ultrasonic flaw detection, a liquid such as oil or water is supplied to the surface of the steel strip as an ultrasonic contact medium. The contact medium realizes efficient transmission of ultrasonic waves between the ultrasonic probe (ultrasonic probe) and the steel strip.

  In the contact medium supply method disclosed in Patent Document 1, two supply pipes are arranged on the upstream side of the ultrasonic probe along the conveying direction of the steel strip. A contact medium having a constant flow rate is supplied from one supply pipe. A contact medium having a proportional flow rate corresponding to the conveying speed of the steel strip is supplied from the other supply pipe.

JP-A-3-29849 JP-A-6-213875 JP-A-7-286994

  In the device described in Patent Document 1, the ultrasonic probe contacts the surface of a flat steel strip. Since the surface of the steel strip moves in one plane, the distance between the ultrasonic probe and the steel strip need not be considered at all. The supply amount of the contact medium is simply determined according to the conveying speed of the steel strip.

  According to at least one aspect of the present invention, it is possible to provide an ultrasonic measurement apparatus capable of sufficiently interposing an acoustic coupling material between a subject and the subject even when the shape of the subject is changed.

  (1) One embodiment of the present invention includes an acoustic matching body having an ultrasonic transmission surface, an ultrasonic transducer element connected to the acoustic matching body, and a fluid acoustic coupling material with respect to the transmission surface. A supply port to be supplied; a distance sensor arranged outside the outline of the ultrasonic transducer element in a plan view from the thickness direction of the acoustic matching body; and a distance sensor for measuring a distance from the subject; and measurement of the distance sensor The present invention relates to an ultrasonic measurement apparatus including a control unit that controls a supply amount of the acoustic coupling material based on a result.

  In the ultrasonic measurement, the transmission surface comes into contact with a subject such as a body surface. In contact, an acoustic coupling material is supplied from the supply port between the subject and the transmission surface. The acoustic coupling material fills between the subject and the transmission surface. At this time, the transmission surface may be in contact with the subject in a specific region and may be spaced from the subject in other regions. The distance between the transmission surface and the subject varies depending on the shape of the subject. When the acoustic coupling material is supplied in accordance with such a change in distance, the ultrasonic measurement apparatus can sufficiently interpose the acoustic coupling material with the subject. The acoustic coupling material can effectively fill the space between the transmission surface and the subject.

  (2) The distance sensor may be formed of an ultrasonic transducer element. The distance sensor can be built on the same substrate as the ultrasonic transducer element that is coupled to the acoustic matching body. Thus, the distance sensor can be manufactured simultaneously with the formation of the ultrasonic transducer element.

  (3) In the ultrasonic measurement device, it is desirable that the distance sensor has a resonance frequency lower than a resonance frequency of an ultrasonic transducer element connected to the acoustic matching body. Such a resonance frequency is more easily propagated in the air than the resonance frequency used for ultrasonic measurement. Therefore, the distance sensor can efficiently measure the distance to the subject.

  (4) The distance sensor may include a contact and a pressure sensor that measures a pressure transmitted from the contact. The distance sensor can be realized relatively easily with a pressure sensor.

  (5) The ultrasonic measurement device may further include a movement sensor that detects a movement direction of the transmission surface. The distance sensor measures the distance to the subject in front of the transmission surface in the traveling direction. Therefore, the shape of the subject ahead in the traveling direction can be generally predicted based on the measurement result of the distance sensor. If the supply amount of the acoustic coupling material is controlled in accordance with the expected shape, the ultrasonic measurement apparatus sufficiently interposes the acoustic coupling material with the subject even when the transmission surface moves relative to the subject. be able to. The acoustic coupling material can effectively fill the space between the transmission surface and the subject.

  (6) The transmission surface may be formed of curved surfaces formed by buses parallel to each other. In the ultrasonic measurement, the transmission surface may be pressed against a subject such as a body surface. The contact area between the subject and the transmission surface changes depending on the degree of pressing. As a result, the size of the gap changes between the subject and the transmission surface. When the acoustic coupling material is supplied in accordance with such changes, the ultrasonic measurement apparatus can sufficiently interpose the acoustic coupling material with the subject. The acoustic coupling material can effectively fill the space between the transmission surface and the subject.

  (7) In another aspect of the present invention, an acoustic matching body having an ultrasonic transmission surface, an ultrasonic transducer element connected to the acoustic matching body, and a fluid acoustic coupling material are supplied to the transmission surface The present invention relates to an ultrasonic probe comprising a supply port that performs measurement, and a sensor that is disposed outside the outline of the ultrasonic transducer element in a plan view and measures a distance from a subject. Such an ultrasonic probe can be used to realize an ultrasonic measurement apparatus.

  (8) According to still another aspect of the present invention, there is provided an acoustic matching body including an ultrasonic transmission surface, an ultrasonic transducer element connected to the acoustic matching body, and a fluid acoustic coupling toward the transmission surface. A supply port for supplying a material and a drive signal of a first frequency and a drive signal of a second frequency lower than the first frequency are supplied to the ultrasonic transducer element and transmitted by the drive signal of the second frequency. The present invention relates to an ultrasonic measurement apparatus including a control unit that controls a supply amount of the acoustic coupling material in accordance with a distance measured using the ultrasonic waves.

  In the ultrasonic measurement, the transmission surface comes into contact with a subject such as a body surface. In contact, an acoustic coupling material is supplied from the supply port between the subject and the transmission surface. The acoustic coupling material fills between the subject and the transmission surface. At this time, the transmission surface may be in contact with the subject in a specific region and may be spaced from the subject in other regions. The distance between the transmission surface and the subject varies depending on the shape of the subject. When the acoustic coupling material is supplied in accordance with such a change in distance, the ultrasonic measurement apparatus can sufficiently interpose the acoustic coupling material with the subject. The acoustic coupling material can effectively fill the space between the transmission surface and the subject.

1 is an external view schematically showing a specific example of an electronic apparatus according to an embodiment, that is, an ultrasonic diagnostic apparatus. It is an enlarged front view of an ultrasonic probe. It is an expansion perspective view of an ultrasonic transducer element unit. It is an enlarged plan view of an ultrasonic device. FIG. 5 is a cross-sectional view of an ultrasonic transducer element unit corresponding to a cross-sectional view along the line AA in FIG. 4. It is an expanded sectional view showing roughly the structure of the 1st distance sensor. It is a conceptual diagram which shows roughly a part of control system of an ultrasonic diagnosing device. FIG. 6 is a cross-sectional view of an ultrasonic transducer element unit that corresponds to FIG. 5 and is pressed against a body surface. FIG. 4 is an enlarged perspective view of an ultrasonic transducer element unit corresponding to FIG. 3 and schematically showing diffusion of an acoustic coupling material. It is an expanded sectional view showing roughly operation of the 1st distance sensor. It is an expansion perspective view which shows operation | movement of a 2nd distance sensor roughly. It is an enlarged partial top view of the ultrasonic device which shows roughly the structure of the distance sensor concerning other embodiments. It is an expanded sectional view showing roughly the structure of the distance sensor concerning other embodiments. It is an expanded sectional view showing roughly operation of a movement sensor of an ultrasonic diagnostic equipment concerning other embodiments.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

(1) Overall Configuration of Ultrasonic Diagnostic Apparatus FIG. 1 schematically shows a specific example of an electronic apparatus according to an embodiment of the present invention, that is, a configuration of an ultrasonic diagnostic apparatus 11. The ultrasonic diagnostic apparatus 11 includes an apparatus terminal 12 and an ultrasonic probe (probe) 13. The apparatus terminal 12 and the ultrasonic probe 13 are connected to each other by a cable 14. The apparatus terminal 12 and the ultrasonic probe 13 exchange electric signals through the cable 14. A display panel 15 is incorporated in the device terminal 12. The screen of the display panel 15 is exposed on the surface of the device terminal 12. In the device terminal 12, as will be described later, an image is generated based on the ultrasonic waves detected by the ultrasonic probe 13. The imaged detection result is displayed on the screen of the display panel 15.

  As shown in FIG. 2, the ultrasonic probe 13 has a housing 16. An ultrasonic transducer element unit (hereinafter referred to as “element unit”) 17 is accommodated in the housing 16. The surface of the element unit 17 can be exposed on the surface of the housing 16. The element unit 17 outputs an ultrasonic wave from the surface and receives a reflected wave of the ultrasonic wave. In addition, the ultrasonic probe 13 can include a probe head 13b that is detachably connected to the probe main body 13a. At this time, the element unit 17 can be incorporated in the housing 16 of the probe head 13b.

  FIG. 3 schematically shows the configuration of the element unit 17. The element unit 17 includes an ultrasonic device 18 and an acoustic matching complex 19. As will be described later, the ultrasonic device 18 includes a plurality of ultrasonic transducer elements arranged in an array on a substrate such as a substrate. The acoustic matching composite 19 is coupled to the surface of the ultrasonic device 18. The acoustic matching complex 19 includes an acoustic matching layer 21 and an acoustic lens (acoustic matching body) 22. The acoustic matching layer 21 is formed on the surface of the ultrasonic device 18. The acoustic matching layer 21 is in close contact with the surface of the ultrasonic device 18 throughout. The acoustic lens 22 is formed on the surface of the acoustic matching layer 21. The acoustic lens 22 may be integrated with the acoustic matching layer 21. The acoustic matching layer 21 realizes acoustic impedance matching between the test object such as a living body and the ultrasonic device 18. The acoustic lens 22 plays a role of collecting ultrasonic waves simultaneously emitted from the individual ultrasonic transducer elements into one focal point. Here, the acoustic matching composite 19 is made of, for example, a silicone resin. In addition, a first flexible printed wiring board (hereinafter referred to as “first wiring board”) 23 and a second flexible printed wiring board (hereinafter referred to as “second wiring board”) 24 are individually connected to the ultrasonic device 18. . The ultrasonic device 18 is lined with a backing material 25.

  The acoustic lens 22 has a protruding curved surface (transmission surface) 26 formed by generatrix lines extending in parallel to each other in the first direction D1. A plurality of grooves 27 are formed in the curved surface 26. The groove 27 extends in the second direction D <b> 2 following the intersection line between the curved surface 26 and the plane intersecting the generatrix of the curved surface 26. The first direction D1 and the second direction D2 are defined within a plane including the surface of the ultrasonic device 18, for example, and are orthogonal to each other. Here, the intersection line is defined by the curved surface 26 and a plane orthogonal to the generatrix of the curved surface 26. The grooves 27 are arranged at equal intervals in the first direction (bus line direction) D1.

  The first distance sensors 28a and 28b and the second distance sensors 29a and 29b are installed outside the outline of the ultrasonic device 18 in plan view. The first distance sensors 28a and 28b and the second distance sensors 29a and 29b measure the distance from the subject such as the body surface in ultrasonic diagnosis. The measured distance is output from the first distance sensors 28a and 28b and the second distance sensors 29a and 29b as electric signals. The first distance sensors 28a and 28b are arranged at positions where the ultrasonic device 18 is sandwiched in the direction defined by the intersection line between the plane perpendicular to the generatrix of the curved surface 26 and the surface of the ultrasonic device 18, that is, the second direction D2. The The second distance sensors 29a and 29b are arranged at positions where the ultrasonic device 18 is sandwiched in the direction defined by the intersection line between the plane parallel to the generatrix of the curved surface 26 and the surface of the ultrasonic device 18, that is, the first direction D1. The It is desirable that the first distance sensors 28a and 28b and the second distance sensors 29a and 29b be arranged as far away from the curved surface 26 as possible.

  FIG. 4 schematically shows a plan view of the ultrasonic device 18. The ultrasonic device 18 includes a base 31. An element array 32 is formed on the base 31. The element array 32 includes an array of ultrasonic transducer elements (hereinafter referred to as “elements”) 33. The array is formed of a matrix having a plurality of rows and a plurality of columns. In addition, a staggered arrangement may be established in the array. In the staggered arrangement, the even-numbered element groups 33 may be shifted from the odd-numbered element groups 33 by half the row pitch. The number of elements in one of the odd and even columns may be one less than the number of the other element. The first distance sensors 28a and 28b and the second distance sensors 29a and 29b may be disposed at least outside the outline of the element array 32 in plan view.

  Each element 33 includes a vibration film 34. In FIG. 4, the outline of the diaphragm 34 is drawn with a dotted line in a plan view in a direction orthogonal to the film surface of the diaphragm 34 (a plan view in the thickness direction of the substrate). The inner side of the contour corresponds to the inner region of the vibration film 34. The outer side of the contour corresponds to the outer region of the vibration film 34. A piezoelectric element 35 is formed on the vibration film 34. The piezoelectric element 35 includes an upper electrode 36, a lower electrode 37, and a piezoelectric film 38. A piezoelectric film 38 is sandwiched between the upper electrode 36 and the lower electrode 37 for each element 33. These are stacked in the order of the lower electrode 37, the piezoelectric film 38 and the upper electrode 36. The ultrasonic device 18 is configured as a single ultrasonic transducer element chip.

  A plurality of first conductors 39 are formed on the surface of the base 31. The first conductors 39 extend parallel to each other in the row direction of the array. One first conductor 39 is assigned to each element 33 in one row. One first conductor 39 is commonly connected to the piezoelectric film 38 of the elements 33 arranged in the row direction of the array. The first conductor 39 forms the upper electrode 36 for each element 33. Both ends of the first conductor 39 are connected to a pair of lead wires 41, respectively. The lead wires 41 extend in parallel to each other in the column direction of the array. Accordingly, all the first conductors 39 have the same length. Thus, the upper electrode 36 is connected in common to the elements 33 of the entire matrix. The first conductor 39 can be formed of, for example, iridium (Ir). However, other conductive materials may be used for the first conductor 39.

  A plurality of second conductors 42 are formed on the surface of the base 31. The second conductors 42 extend parallel to each other in the column direction of the array. One second conductor 42 is assigned to each element 33 in one row. One second conductor 42 is disposed in common on the piezoelectric film 38 of the elements 33 arranged in the column direction of the array. The second conductor 42 forms a lower electrode 37 for each element 33. For example, a laminated film of titanium (Ti), iridium (Ir), platinum (Pt), and titanium (Ti) can be used for the second conductor 42. However, other conductive materials may be used for the second conductor 42.

  Energization of the element 33 is switched for each column. Line scan and sector scan are realized according to such switching of energization. Since the elements 33 in one column output ultrasonic waves simultaneously, the number of columns, that is, the number of rows in the array, can be determined according to the output level of the ultrasonic waves. For example, the number of lines may be set to about 10 to 15 lines. In the figure, five lines are drawn without illustration. The number of columns in the array can be determined according to the spread of the scanning range. The number of columns may be set to 128 columns or 256 columns, for example. In the figure, there are omitted and 8 columns are drawn. The roles of the upper electrode 36 and the lower electrode 37 may be interchanged. That is, while the lower electrode is commonly connected to the elements 33 of the entire matrix, the upper electrode may be commonly connected to the elements 33 for each column of the array.

  The outline of the base 31 has a first side 31a and a second side 31b that are separated by a pair of straight lines parallel to each other and face each other. One line of the first terminal array 43 a is arranged between the first side 31 a and the outline of the element array 32. One line of the second terminal array 43 b is arranged between the second side 31 b and the outline of the element array 32. The first terminal array 43a can form one line parallel to the first side 31a. The second terminal array 43b can form one line parallel to the second side 31b. The first terminal array 43 a includes a pair of upper electrode terminals 44 and a plurality of lower electrode terminals 45. Similarly, the second terminal array 43 b includes a pair of upper electrode terminals 46 and a plurality of lower electrode terminals 47. Upper electrode terminals 44 and 46 are connected to both ends of one lead wiring 41, respectively. The lead wiring 41 and the upper electrode terminals 44 and 46 may be formed in plane symmetry on a vertical plane that bisects the element array 32. Lower electrode terminals 45 and 47 are connected to both ends of one second conductor 42, respectively. The second conductor 42 and the lower electrode terminals 45 and 47 may be formed in plane symmetry on a vertical plane that bisects the element array 32. Here, the outline of the base 31 is formed in a rectangular shape. The outline of the base 31 may be square or trapezoidal.

  The first wiring board 23 covers the first terminal array 43a. Conductive lines, that is, first signal lines 48 are formed at one end of the first wiring board 23 individually corresponding to the upper electrode terminal 44 and the lower electrode terminal 45. The first signal line 48 is individually faced and joined to the upper electrode terminal 44 and the lower electrode terminal 45. Similarly, the second wiring board 24 covers the second terminal array 43b. Conductive lines, that is, second signal lines 49 are formed at one end of the second wiring board 24 so as to individually correspond to the upper electrode terminal 46 and the lower electrode terminal 47. The second signal lines 49 are individually faced and joined to the upper electrode terminal 46 and the lower electrode terminal 47, respectively.

  As shown in FIG. 5, the base 31 includes a substrate 52 and a flexible film 53. A flexible film 53 is formed on the entire surface of the substrate 52. An opening 54 is formed in the substrate 52 for each element 33. The openings 54 are arranged in an array with respect to the substrate 52. The contour of the region where the opening 54 is disposed corresponds to the contour of the element array 32. A partition wall 55 is defined between two adjacent openings 54. Adjacent openings 54 are partitioned by a partition wall 55. The wall thickness of the partition wall 55 corresponds to the interval between the openings 54. The partition wall 55 defines two wall surfaces in a plane extending parallel to each other. The wall thickness corresponds to the distance between the two wall surfaces. That is, the wall thickness can be defined by the length of a perpendicular line sandwiched between the wall surfaces perpendicular to the wall surfaces. The substrate 52 may be formed of a silicon substrate, for example.

The flexible film 53 includes a silicon oxide (SiO ₂ ) layer 56 laminated on the surface of the substrate 52 and a zirconium oxide (ZrO ₂ ) layer 57 laminated on the surface of the silicon oxide layer 56. The flexible film 53 is in contact with the opening 54. Thus, a part of the flexible film 53 forms the vibration film 34 corresponding to the outline of the opening 54. The vibration film 34 is a portion of the flexible film 53 that can vibrate in the thickness direction of the substrate 52 because it faces the opening 54. The film thickness of the silicon oxide layer 56 can be determined based on the resonance frequency.

  A lower electrode 37, a piezoelectric film 38 and an upper electrode 36 are sequentially stacked on the surface of the vibration film 34. The piezoelectric film 38 can be formed of, for example, lead zirconate titanate (PZT). Other piezoelectric materials may be used for the piezoelectric film 38. Here, the piezoelectric film 38 completely covers the second conductor 42 under the first conductor 39. The short circuit between the first conductor 39 and the second conductor 42 can be avoided by the action of the piezoelectric film 38.

  A backing material 25 is fixed to the back surface of the base 31. The back surface of the base 31 is overlaid on the surface of the backing material 25. The backing material 25 closes the opening 54 on the back surface of the ultrasonic device 18. The backing material 25 can comprise a rigid substrate. Here, the partition wall 55 is coupled to the backing material 25. The backing material 25 is joined to each partition wall 55 at at least one joining region. An adhesive can be used for bonding.

  The acoustic matching layer 21 is laminated on the surface of the base 31. For example, the acoustic matching layer 21 covers the entire surface of the base 31 over the entire surface. As a result, the element array 32, the first and second terminal arrays 43 a and 43 b, and the first and second wiring boards 23 and 24 are covered with the acoustic matching layer 21. The acoustic matching layer 21 protects the structure of the element array 32, the bonding between the first terminal array 43a and the first wiring board 23, and the bonding between the second terminal array 43b and the second wiring board 24.

  The curved surface 26 is formed as, for example, a cylindrical partial cylindrical surface. The curved surface 26 has a first radius of curvature R1 around the central axis of the cylinder. A line of intersection 58 between the plane perpendicular to the curved surface 26 and the curved surface 26 describes an arc having a first radius of curvature R1. The first radius of curvature R1 may be determined based on the ultrasonic frequency and the depth of the region to be examined. At this time, the bottom surface of the groove 27 draws an arc having a second curvature radius R2 smaller than the first curvature radius R1. That is, the groove 27 having a certain depth is formed. However, the depth of the groove 27 may not be constant, and may be deeper toward both ends of the groove 27, for example.

  The acoustic lens 22 is formed with a through hole 59 extending in a direction orthogonal to the surface of the base 31 of the ultrasonic device 18. For example, a pair of through holes 59 is assigned to each individual groove 27. One end of the through hole 59 is a plane 61 that interconnects a bus bar positioned at one end of an intersection line 58 between the plane orthogonal to the curved surface 26 and the curved surface 26 and a bus bar positioned at the other end of the intersection line 58. Open to. The other end of the through hole 59 forms a supply port 59 a with the curved surface 26. The through hole 59 is connected to the groove 27 at the supply port 59a. Here, the supply port 59a is disposed outside the outline of the element array 32 defined in plan view. The groove 27 can extend over the entire length of the intersection line 58 from one end to the other end of the intersection line 58. However, as long as the function of the acoustic lens 22 is not impaired, the groove 27 may be interrupted before reaching the one end and the other end of the intersection line 58 outside the through hole 59.

  On the surface of the acoustic matching layer 21, for example, a groove 62 opened at the first side 31a and the second side 31b of the base 31 is formed. The groove 62 is recessed from the surface of the acoustic matching layer 21. Therefore, when the acoustic lens 22 is formed on the surface of the acoustic matching layer 21, the groove 62 forms a conduit in the acoustic matching composite 19. The other end of the groove 62 is connected to the through hole 59. In this way, a series of passages extending from the first side 31a to the second side 31b of the base 31 is formed by the one groove 62, the one through hole 59, the groove 27, the other through hole 59, and the other groove 62.

  For example, a fluidic acoustic coupling material source 64 is connected to the groove 62. The supply source 64 includes a supply pump 65. The acoustic coupling material is supplied from the supply pump 65 through the pipe line to the groove 62 under a predetermined pressure. A flow control valve 66 is disposed in the pipe line between the supply pump 65 and the groove 62. The flow control valve 66 controls the flow rate of the acoustic coupling material fed into the groove 62. A tank 67 is connected to the supply pump 65. An acoustic coupling material is stored in the tank 67. The supply pump 65 replenishes the acoustic coupling material from the tank 67.

As shown in FIG. 6, the first distance sensors 28 a and 28 b are formed of an element 69. The element 69 includes a vibration film 71. When forming the vibration film 71, the first distance sensors 28 a and 28 b include a substrate 72 and a flexible film 73. A flexible film 73 is formed on the entire surface of the substrate 72. An opening 74 is formed in the substrate 72. The flexible film 73 is in contact with the opening 74. Thus, a part of the flexible film 73 forms the vibration film 71 corresponding to the contour of the opening 74. The vibration film 71 is a part of the flexible film 73 that can vibrate in the thickness direction of the substrate 72 because it faces the opening 74. The size of the opening 74 is larger than the opening 54 of the element 33 described above. Therefore, the resonance frequency of the vibration film 71 is lower than the resonance frequency of the vibration film 34. The flexible film 73 may be composed of a silicon oxide (SiO ₂ ) layer 75 and a zirconium oxide (ZrO ₂ ) layer 76 as described above. On the vibration film 71, a lower electrode 77, a piezoelectric film 78, and an upper electrode 79 are sequentially stacked. The second distance sensors 29a and 29b are configured similarly to the first distance sensors 28a and 28b. The vibration film 71 is in direct contact with air without going through the acoustic matching layer.

  As shown in FIG. 7, the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b are connected to the control unit 81. The control unit 81 can be configured by an arithmetic processing circuit such as a microprocessor unit (MPU). A flow control valve 66 is connected to the controller 81. The flow control valve 66 is installed for each supply port 59a. In addition, the flow control valve 66 may be provided for each group configured by a plurality of supply ports 59a. The controller 81 controls the supply amount of the acoustic coupling material based on the measurement results of the first distance sensors 28a and 28b and the second distance sensors 29a and 29b. Here, the opening degree of the flow control valve 66 is controlled. The controller 81 controls the supply amount of the acoustic coupling material for each supply port 59a.

(2) Operation of Ultrasonic Diagnostic Device Next, the operation of the ultrasonic diagnostic device 11 will be briefly described. A pulse signal is supplied to the piezoelectric element 35 when transmitting ultrasonic waves. The pulse signal is supplied to the element 33 for each column through the lower electrode terminals 45 and 47 and the upper electrode terminals 44 and 46. In each element 33, an electric field acts on the piezoelectric film 38 between the lower electrode 37 and the upper electrode 36. The piezoelectric film 38 vibrates with ultrasonic waves. The vibration of the piezoelectric film 38 is transmitted to the vibration film 34. Thus, the vibration film 34 vibrates with ultrasonic waves. As a result, a desired ultrasonic beam is emitted toward the subject (for example, inside the human body).

  The ultrasonic reflected wave vibrates the vibration film 34. The ultrasonic vibration of the vibration film 34 causes the piezoelectric film 38 to vibrate at a desired frequency. A current is output from the piezoelectric element 35 in accordance with the piezoelectric effect of the piezoelectric element 35. In each element 33, a potential is generated between the upper electrode 36 and the lower electrode 37. The current is output as an electrical signal from the lower electrode terminals 45 and 47 and the upper electrode terminals 44 and 46. In this way, ultrasonic waves are detected.

  Transmission and reception of ultrasonic waves are repeated. As a result, line scan and sector scan are realized. When the scan is completed, an image is formed based on the digital signal of the output signal. The formed image is displayed on the screen of the display panel 15.

  As shown in FIG. 8, when the ultrasonic probe 13 is pressed against the body surface BD in ultrasonic diagnosis, the curved surface 26 of the acoustic lens 22 is in close contact with the body surface BD. The groove 27 forms a conduit between the body surface BD and the acoustic lens 22. In this way, a pipe line that connects the first side 31a and the second side 31b of the base 31 to each other is formed. When an acoustic coupling material (medium) such as water is supplied from the groove 62, the groove 27 is filled with water. The groove 27 functions as a water passage. Even if the curved surface 26 is pressed against the flexible body surface BD, water can spread over the entire length of the groove 27. Thereafter, as shown in FIG. 9, the water overflows from the groove 27 to the curved surface 26. In this way, the water can spread along the curved surface 26. Water may fill the grooves 27 at least between the through holes 59 for each individual groove 27. Thus, water is sufficiently supplied to the curved surface 26, that is, the outer surface within the effective range of the acoustic lens 22. Water can sufficiently spread between the effective range of the curved surface 26 and the body surface BD.

  As shown in FIG. 10, for example, when the measurement site is different in the human body, the distances between the first distance sensors 28a and 28b and the body surfaces BD1 and BD2 change. For example, the radius of curvature of the curved shape of the thigh is larger than the curved shape of the arm. Therefore, the measured values of the first distance sensors 28a and 28b increase when measuring the curved shape of the arm (body surface BD2) compared to the curved shape of the thigh (body surface BD1). At this time, the volume of the space formed between the curved surface 26 and the body surface BD1, BD2 increases. The controller 81 increases the opening degree of the flow control valve 66 in accordance with the increase in the measured values of the first distance sensors 28a and 28b. Thus, the amount of water supplied increases as the volume of the space increases. As a result, the ultrasonic diagnostic apparatus 11 can sufficiently interpose water between the body surface BD2 and the curved surface 26 of the acoustic lens 22. Water can effectively fill between the curved surface 26 and the body surface BD1, BD2. When the first distance sensor 28a and the first distance sensor 28b output different measurement values, the flow rate of water may be controlled for each flow control valve 66 according to the measurement values. The distance measurement and the supply amount control may be performed at regular time intervals.

  As shown in FIG. 11, depending on the orientation of the ultrasonic probe 13, for example, when the measurement site in the human body is different, the distances between the second distance sensors 29 a and 29 b and the body surfaces BD 1 and BD 2 change. The measured values of the second distance sensors 29a and 29b increase when measuring a curved shape (body surface BD2) having a small curvature radius compared to a curved shape (body surface BD1) having a large curvature radius. At this time, the volume of the space formed between the curved surface 26 and the body surface BD1, BD2 increases. The controller 81 increases the opening degree of the flow control valve 66 in accordance with the increase in the measured values of the second distance sensors 29a and 29b. Thus, the amount of water supplied increases as the volume of the space increases. As a result, the ultrasonic diagnostic apparatus 11 can sufficiently interpose water between the body surface BD2 and the curved surface 26 of the acoustic lens 22. Water can effectively fill between the curved surface 26 and the body surface BD1, BD2. When the second distance sensor 29a and the second distance sensor 29b output different measurement values, the flow rate of water may be controlled for each flow control valve 66 according to the measurement values.

  In the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b, the resonance frequency of the vibration film 71 is lower than the resonance frequency of the vibration film 34. Therefore, even if air is interposed between the vibration film 71 and the body surfaces BD1 and BD2, attenuation of ultrasonic waves can be suppressed. In addition, in the first distance sensors 28a and 28b and the second distance sensors 29a and 29b, the vibration film 71 is in contact with air without passing through the acoustic matching layer. Such omission of the acoustic matching layer can further contribute to the suppression of ultrasonic attenuation. However, a very thin protective film may be formed on the vibration film 71. The protective film reinforces the strength of the vibration film 71. In addition, for example, when the distance is estimated by the first distance sensors 28a and 28b and the second distance sensors 29a and 29b based on the sound velocity of air, the first distance sensors 28a and 28b and the second distance sensors 29a and 29b are as much as possible. Is kept away from the curved surface 26, water is prevented from intervening between the first distance sensors 28a, 28b and the second distance sensors 29a, 29b and the body surface BD1, BD2, and the accuracy of distance estimation is improved. Can do.

(3) Distance Sensors According to Other Embodiments As shown in FIG. 12, the first distance sensors 28a and 28b and the second distance sensors 29a and 29b may be built in the base 31 of the element unit 17. In this case, the vibration films 71 of the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b are similarly partitioned by the flexible film 53 in contact with the opening 54 of the base 31. The lower electrodes 77 and the upper electrodes 79 of the first distance sensors 28a and 2b and the second distance sensors 29a and 29b may be connected to the electrode terminals in the first terminal array 43a and the second terminal array 43b. However, the elements 69 of the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b are arranged outside the acoustic matching complex 19. The vibration films 71 of the first distance sensors 28a and 28b and the second distance sensors 29a and 29b are in direct contact with air without going through the acoustic matching layer. Thus, the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b can be manufactured simultaneously with the formation of the element array 32. Other structures are the same as those of the element unit 17 described above.

  As shown in FIG. 13, the first distance sensors 28 a and 28 b and the second distance sensors 29 a and 29 b may include a pressure sensor 82. A contact 83 is connected to the pressure sensor 82. The pressure sensor 82 measures the pressure transmitted from the contactor 83. For example, when the contactor 83 is formed of an elastic body such as a spring, the pressure applied to the pressure sensor 82 changes according to the distance between the pressure sensor 82 and the body surface BD. The shorter the distance, the higher the pressure. Therefore, the distance can be measured based on the measured value of the pressure sensor 82.

  In addition, the element 33 in the element array 32 may also serve as the first distance sensors 28a and 28b and the second distance sensors 29a and 29b. In this case, the control unit 81 supplies the first frequency drive signal and the second frequency drive signal lower than the first frequency to the element 33. The distance is measured between the element 33 and the body surface BD when the driving signal of the second frequency is supplied. The first distance sensors 28a and 28b and the second distance sensors 29a and 29b can be realized only by changing the control unit 81.

(4) Ultrasonic Diagnostic Apparatus According to Other Embodiment As shown in FIG. 14, in the ultrasonic diagnostic apparatus 11, the movement sensor 84 may be installed outside the outline of the ultrasonic device 18 in a plan view. The movement sensor 84 detects the movement direction of the curved surface 26 with respect to the body surfaces BD1 and BD2. The first distance sensors 28a and 28b and the second distance sensors 29a and 29b measure distances from the body surfaces BD1 and BD2 in front of the curved surface 26 in the traveling direction. Therefore, the shapes of the body surfaces BD1 and BD2 ahead of the traveling direction can be generally predicted based on the measurement results of the first distance sensors 28a and 28b and the second distance sensors 29a and 29b. If the supply amount of the acoustic coupling material such as water is controlled in accordance with the expected shape, the ultrasonic diagnostic apparatus 11 is connected to the body surfaces BD1 and BD2 even when the curved surface 26 moves relative to the body surfaces BD1 and BD2. A sufficient acoustic coupling material can be interposed between them. The acoustic coupling material can effectively fill between the curved surface 26 and the body surface BD1, BD2.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. In addition, the configurations and operations of the ultrasonic diagnostic apparatus 11, the ultrasonic probe 13, the element unit 17, the element 33, the control unit 81, and the like are not limited to those described in the present embodiment, and various modifications are possible.

  DESCRIPTION OF SYMBOLS 11 Ultrasonic diagnostic apparatus as an electronic device and an ultrasonic measuring device, 13 Ultrasonic probe, 22 Acoustic matching body (acoustic lens), 26 Transmission surface (curved surface), 28a Distance sensor (first distance sensor), 28b Distance sensor (First distance sensor), 29a distance sensor (second distance sensor), 29b distance sensor (second distance sensor), 33 ultrasonic transducer element, 59a supply port, 69 ultrasonic transducer element, 81 control unit, 82 Pressure sensor, 83 contact, 84 movement sensor, BD subject (body surface), BD1 subject (body surface), BD2 subject (body surface).

Claims (8)

An acoustic matching body having an ultrasonic transmission surface;
An ultrasonic transducer element connected to the acoustic matching body;
A supply port for supplying a fluid acoustic coupling material to the transmission surface;
A distance sensor that is disposed outside the outline of the ultrasonic transducer element in a plan view from the thickness direction of the acoustic matching body, and measures the distance to the subject;
A control unit for controlling the supply amount of the acoustic coupling material based on the measurement result of the distance sensor;
An ultrasonic measurement apparatus comprising:   The ultrasonic measurement apparatus according to claim 1, wherein the distance sensor is formed of an ultrasonic transducer element.   The ultrasonic measurement apparatus according to claim 2, wherein the distance sensor has a resonance frequency lower than a resonance frequency of an ultrasonic transducer element connected to the acoustic matching body.   The ultrasonic measurement apparatus according to claim 1, wherein the distance sensor includes a contact and a pressure sensor that measures a pressure transmitted from the contact.   5. The ultrasonic measurement apparatus according to claim 1, further comprising a movement sensor that detects a movement direction of the transmission surface. 6.   The ultrasonic measurement apparatus according to claim 1, wherein the transmission surface is formed by curved surfaces formed by generatrixes parallel to each other. An acoustic matching body having an ultrasonic transmission surface;
An ultrasonic transducer element connected to the acoustic matching body;
A supply port for supplying a fluid acoustic coupling material to the transmission surface;
A sensor that is disposed outside the outline of the ultrasonic transducer element in a plan view and measures a distance from the subject;
An ultrasonic probe comprising: An acoustic matching body having an ultrasonic transmission surface;
An ultrasonic transducer element connected to the acoustic matching body;
A supply port for supplying a fluid acoustic coupling material toward the transmission surface;
The ultrasonic transducer element is supplied with a drive signal having a first frequency and a drive signal having a second frequency lower than the first frequency, and measurement is performed using an ultrasonic wave transmitted by the drive signal having the second frequency. A control unit for controlling the supply amount of the acoustic coupling material according to the distance to be
An ultrasonic measurement apparatus comprising:

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