JP5190979B2 - Two-dimensional hardness measuring device - Google Patents

Description

  The present invention relates to a two-dimensional hardness measurement apparatus, and more particularly to a two-dimensional hardness measurement apparatus that measures a two-dimensional hardness by arranging a plurality of probe elements in a two-dimensional array.

  For example, in breast cancer screening or the like, X-ray imaging or the like is performed across a patient's diagnosis site, and it is determined whether there is a hard place inside the living body, that is, a lump. In addition, the presence or degree of a lump is determined by palpation, and the latter may be performed by the patient himself / herself under the guidance of a doctor in addition to palpation by an expert such as a doctor.

  Since it is difficult to determine where the lump is inside the living body from the appearance of the living body of the patient or the like, it may be necessary to perform X-ray photography or palpation over a wide range. In addition, in a method of performing diagnosis across a patient's diagnostic site such as X-ray imaging, a sufficient range may not be sandwiched depending on the diagnostic site or the patient's body shape. In addition, the method by palpation requires experience, and individual differences among palpators appear in the presence / absence of lumps and the degree of the judgment, making quantitative judgment difficult.

  Therefore, in Patent Document 1, a plurality of probe elements are two-dimensionally arranged as a living body lump inspection apparatus, and each probe element is sequentially selected by a hardness calculation switching circuit and connected to a hardness calculation unit. The structure to be disclosed is disclosed. Here, each probe element is configured by laminating a vibrator that injects vibration into a living tissue, a vibration detection sensor that detects reflected waves, and a substantially hemispherical contact ball on a mounting base. Are two-dimensionally arranged on the probe base. In addition, the hardness calculation unit includes a phase shift circuit that changes the frequency according to the phase difference between the input waveform to the vibrator and the output waveform from the vibration detection sensor, and determines the hardness of the living tissue from the frequency change. calculate. Each probe element is provided with a pressure sensor, and it is stated that hardness data of the probe element whose pressing pressure is within a predetermined range is displayed two-dimensionally on the display unit and the lump is inspected. . Details of the phase shift circuit are disclosed in Patent Document 2.

  Patent Document 3 discloses a configuration in which a plurality of piezoelectric vibrators are fixed in a matrix on one main surface of a substrate made of a backing material in an ultrasonic probe as a sensor array used in an ultrasonic diagnostic apparatus. Is done. Here, the piezoelectric vibrator includes a plurality of stacked piezoelectric layers, internal electrodes are formed between the piezoelectric layers, and external electrodes are formed on both end surfaces of the piezoelectric layers. Describes that a plurality of piezoelectric layers are bonded on a substrate so as to be laminated in a direction parallel to the main surface of the substrate.

JP 2004-283547 A JP-A-9-145691 JP 2001-103600 A

  According to the living body lump inspection apparatus disclosed in Patent Document 1, a plurality of probe elements can be arranged two-dimensionally, and a two-dimensional distribution of the hardness of the living body can be obtained using the phase shift method. . Here, each probe element is configured by laminating a transducer, a vibration detection sensor, and a substantially hemispherical contact ball on a mounting base, and each mounting base is two-dimensionally arranged on the probe base. . Therefore, here, a disk-shaped vibrator, a vibration detection sensor, and a substantially hemispherical contact ball are manufactured, and these are sequentially stacked on a mounting base to manufacture one probe element, thus manufactured. Since a large number of probe elements are required, man-hours are required and cost reduction is limited.

  Moreover, according to the probe element of patent document 1, it press-contacts with a biological body with a substantially hemispherical contact ball. Therefore, the contact area of the contact ball differs depending on the depth of pressure contact, and depending on the method of pressure contact, there may be a difference in the result of hardness measurement.

  An object of the present invention is to provide a two-dimensional hardness measuring apparatus using a probe element capable of reducing costs. Another object is to provide a two-dimensional hardness measuring apparatus that is less affected by the manner of pressure welding. The following means contribute to at least one of the above objects.

A two-dimensional hardness measuring apparatus according to the present invention is a plurality of probe elements that are pressed against a measurement target via a contact sheet, and each of the probe elements is a vibrator that injects vibration into the measurement target. And a plurality of probe elements each having a vibration detection sensor for detecting a reflected wave from the object to be measured, a lead terminal drawn from each of the vibrator and the vibration detection sensor, and a wiring to which each lead terminal is connected A circuit board, in which a vibration insulating member is disposed between a plurality of probe elements, lead terminals from each probe element are connected to corresponding wirings, and the plurality of probe elements are arranged in a two-dimensional array. a holding substrate for holding arranged on, provided between the signal output terminal of the signal input terminal of vibration Doko vibration detection sensors, hard to calculate the hardness of the object to be measured of the parts in contact with the transducer element Calculator, each probe element and hardness calculator A hardness calculation switching circuit for sequentially switching the connection between the two, and a display for two-dimensionally displaying the hardness calculated for each probe element, the hardness calculator at the signal output end of the vibration detection sensor Provided between the amplifier to which the input terminal is connected, the output terminal of the amplifier and the signal input terminal of the vibrator, and forms a closed loop circuit together with the vibrator, vibration detection sensor, and amplifier, and the input waveform and vibration to the vibrator When a phase difference occurs in the output waveform from the detection sensor, a phase shift circuit that changes the frequency of the phase difference and shifts it to zero, and maintains the resonance of the closed loop circuit, and a frequency for shifting the phase difference to zero A hardness output means for detecting a change amount, calculating a hardness from the detected frequency change amount, and outputting the hardness, and each probe element contacts with a constant contact area regardless of the press contact depth Has a contact surface shape And wherein the door.

  In the two-dimensional hardness measuring apparatus according to the present invention, each probe element preferably has a flat contact surface shape in a direction perpendicular to the pressure contact direction.

  In the two-dimensional hardness measuring apparatus according to the present invention, it is preferable that each probe element has a vibrator and a vibration detection sensor stacked in a direction perpendicular to the pressure contact direction.

  In the two-dimensional hardness measuring apparatus according to the present invention, the vibrator has a rectangular planar shape formed by dividing a flat vibrator plate vertically and horizontally in a plane, and the vibration detection sensor is The flat vibration detection sensor plate preferably has a rectangular planar shape formed by dividing the flat vibration detection sensor plate vertically and horizontally in a plane.

  In the two-dimensional hardness measuring apparatus according to the present invention, the holding substrate is preferably a circuit board on which at least a part of circuit elements constituting the hardness calculator and the hardness calculation switching circuit is mounted. .

  With at least one of the above-described configurations, the two-dimensional hardness measuring apparatus arranges a plurality of probe elements two-dimensionally, presses them against the object to be measured, and uses the phase shift method to measure the object to be measured. A two-dimensional distribution of hardness is obtained, and each probe element has a contact surface shape that contacts with a constant contact area regardless of the press contact depth. Therefore, it is possible to suppress the influence of the pressure contact in the hardness measurement.

  Further, in the two-dimensional hardness measuring apparatus, each probe element has a flat contact surface shape in a direction perpendicular to the pressure contact direction, so that it contacts the object to be measured with a flat contact surface. In the hardness measurement, it is possible to suppress the influence of the pressure welding method.

  In the two-dimensional hardness measuring apparatus, each probe element has a transducer and a vibration detection sensor stacked in a direction perpendicular to the pressure contact direction. As a result, the two-dimensional hardness measuring device can be reduced in size as compared with the method in which the vibrator and the vibration detection sensor are arranged side by side in a plane.

  In the two-dimensional hardness measuring device, the vibrator has a rectangular planar shape formed by dividing a flat vibrator plate vertically and horizontally in a plane, and the vibration detection sensor has a flat plate shape. It has a rectangular planar shape formed by dividing the vibration detection sensor plate vertically and horizontally in a plane. In other words, both the vibrator and the vibration detection sensor can be obtained by dividing a plate-shaped raw material vertically and horizontally, so that it is not necessary to make a disk shape like the prior art, and the cost is greatly reduced. be able to.

  In the two-dimensional hardness measuring apparatus, the holding substrate is a circuit substrate on which at least a part of the circuit elements constituting the hardness calculator and the hardness calculation switching circuit is mounted. Compared with the method of providing, the two-dimensional hardness measuring apparatus can be made smaller.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a living body, particularly a living tissue for checking breast cancer, will be described as a measurement target. However, any object that measures hardness by pressure welding may be used, and living tissues other than living tissue for checking breast cancer may be used. It may be. For example, it may be a living tissue for generally checking the lump of the living body. In general, it may be a living tissue for examining the distribution of hardness and softness. Moreover, it is good also considering substances other than a biological tissue as a measuring object.

  In the following description, it is assumed that the probe body includes a plurality of probe elements and a circuit board on which simple circuit components are mounted, and the arithmetic processing function is included in the main body. Of course, the probe body may include a part or all of the calculation function.

  The dimensions, materials, etc. described below are only examples for explanation, and can be appropriately changed according to the specifications of the two-dimensional hardness measuring apparatus.

  FIG. 1 is a diagram illustrating an overall configuration of a two-dimensional hardness measurement apparatus 10. The two-dimensional hardness measuring device 10 is a device that measures hardness two-dimensionally by arranging a plurality of probe elements in a two-dimensional array. In the following, the two-dimensional hardness measuring device 10 will be simply described as the hardness measuring device 10 unless otherwise specified.

  Here, the hardness measuring apparatus 10 uses a living tissue 8 for checking breast cancer as a measurement target, specifically a breast tissue as a measurement target. Then, the probe portion 20 is pressed against the biological tissue 8, and the hardness of the biological tissue 8 is detected two-dimensionally by a plurality of two-dimensionally arranged probe elements constituting the probe portion 20. Is displayed as a two-dimensional hardness distribution.

  As described above, the hardness measurement apparatus 10 includes the probe unit 20 that is pressed against the living tissue 8, the interface circuit 50, and the main body unit 60 that displays a two-dimensional hardness distribution.

  FIG. 2 is a block diagram showing the configuration of the hardness measuring apparatus 10. The probe unit 20 includes 64 probe elements 40, and each probe element 40 includes a transducer 42 and a vibration detection sensor 44. The main body 60 includes a hardness calculator 70, a hardness calculation switching circuit 62 that sequentially switches the connection between each probe element 40 and the hardness calculator 70, and each probe calculated by the hardness calculator 70. A display processing unit 92 that performs processing for converting the hardness of the touch element 40 into a two-dimensional display, and a two-dimensional hardness display 94 that displays the processed result are configured.

  Although not shown in FIG. 2, the interface circuit 50 described in FIG. 1 is provided between the probe unit 20 and the main body unit 60. The interface circuit 50 is a circuit provided for matching the signal system of the probe unit 20 and the signal system of the main body unit 60. For example, a level shifter for adjusting the voltage level and impedance matching between signals are provided. The buffer circuit is configured.

  FIG. 3 is a perspective view of the probe unit 20. The probe unit 20 includes a distal end portion 22 that is pressed against a measurement target and a grip portion 24 that is gripped by an inspector with a hand. The size of the grip portion 24 can be held by the palm and is preferably sufficient to apply a pressing force, and is set so as not to be too small or too large. In some cases, the grip portion 24 may be a handle type.

  The distal end portion 22 has a flat pressure contact surface 26, and a probe element assembly 30 in which a total of 64 probe elements 40 of 8 columns vertically and 8 rows horizontally are arranged inside the pressure contact surface 26. Stored. Although the pressure contact surface of the tip 22 is partially broken, each probe element 40 has a rectangular pressure contact surface or contact surface, and the planar shape of the contact surface is a rectangular shape.

  FIG. 4 is a partial enlarged cross-sectional view showing a state of the probe element assembly 30. The probe element assembly 30 includes a contact sheet 32, a holding substrate 34, a probe element 40 connected and fixed to the holding substrate 34 by a lead terminal 48, and the probe element 40 and the holding substrate 34. And a vibration insulating member 46 provided.

  The probe element 40 is formed by laminating a vibrator 42 and a vibration detection sensor 44. In the example of FIG. 4, the planar shape of the probe element 40 is higher than the rectangular shape of the vibration detection sensor 44. A slightly small planar vibrator 42 is mounted. The planar shape of the vibrator 42 is also a rectangular shape. As an example of the dimensions, the planar shape of the vibration detection sensor 44 is (about 1.5 mm to about 3 mm) × (about 1.5 mm to about 3 mm), and the thickness is about 0.5 mm to about 2 mm. In this case, a square shape may be used. Therefore, the term “rectangular shape” as used herein means a broadly defined rectangular shape including a square shape. In this case, the planar shape of the vibrator 42 can be made slightly smaller than the vibration detection sensor 44 and can have the same thickness.

  As shown in FIG. 4, the size of the vibrator 42 is small when one of the lead terminals 48 is connected to the upper surface of the vibration detection sensor 44 and is extended to the upper holding substrate 34. It is set so as not to contact the vibrator 42. For example, when the vibration detection sensor 44 is about 2 mm × about 2 mm, the vibrator 42 can be about 1.7 mm × about 2 mm. Of course, this is only an example, and other dimensions can be used depending on the connection technology.

  It should be noted that the order of stacking may be reversed so that the vibrator 42 has a larger planar shape, and a vibration detection sensor 44 having a planar shape smaller than the planar shape of the vibrator 42 is mounted thereon.

  FIG. 5 is a diagram for explaining a method for manufacturing the vibrator 42. The vibrator 42 is manufactured by dividing the flat vibrator plate 100 vertically and horizontally in a plane. The vibrator plate 100 is formed by laminating the upper electrode layer 104 and the lower electrode layer 106 on both surfaces of the piezoelectric material layer 102, respectively. The vibrator plate 100 may be formed by laminating an appropriate metal conductive layer as an upper electrode layer 104 and a lower electrode layer 106 on both surfaces of a lead zinc titanate (PZT) piezoelectric material layer 102. An example of the planar dimension of the vibrator plate 100 is, for example, about 30 mm square to about 60 mm square. Since the vibrator plate 100 is generally a piezoelectric element plate used when manufacturing a piezoelectric element, a piezoelectric element plate having an appropriate specification and shape dimension is selected from commercially available products, and this is used. It can be used as the vibrator plate 100.

  The vibrator plate 100 is cut vertically and horizontally into the planar dimension of the vibrator 42 using, for example, a dicing saw that rotates a cutter blade. In the example of FIG. 5, a state in which 8 × 6 = 48 vibrators 42 are created from one vibrator plate 100 is shown.

  Since the vibration detection sensor 44 can use the same material structure as that of the vibrator 42, a plurality of vibration detection sensors 44 are manufactured from one vibrator plate 100 by the method described in FIG. be able to. In other words, the vibration detection sensor 44 can be manufactured by cutting the same vibration plate 100 used to manufacture the vibrator 42 in the vertical and horizontal directions according to the planar shape of the vibration detection sensor 44. That is, both the vibrator 42 and the vibration detection sensor 44 can be obtained by using the same vibrator plate 100 and changing the cutting dimensions.

  Thus, by making the planar shape of the vibration detection sensor 44 and the vibrator 42 into a square and rectangular shape, the plate-like piezoelectric element plate can be used as the vibrator plate 100, and the vibration detection sensor can be simply cut in the horizontal and vertical directions. 44. The vibrator 42 can be formed. Thereby, compared with the case where the vibration detection sensor 44 and the vibrator 42 are formed in a disk shape, the vibration detection sensor 44 and the vibrator 42 can be obtained at a significantly reduced cost.

  FIG. 6 is a view showing a state in which the probe 40 is formed by laminating the vibration detection sensor 44 and the vibrator 42 thus obtained, and the lead terminal 48 is attached. As described above, both the vibration detection sensor 44 and the vibrator 42 are different from each other only in the planar shape, and each includes the piezoelectric material layer 102 and the upper surface electrode layer 104 and the lower surface electrode layer 106 on both sides thereof. The probe element 40 is formed by soldering the upper electrode layer 104 of the vibration detection sensor 44 and the lower electrode layer 106 of the vibrator 42 or joining them together with a conductive adhesive.

  As the three lead terminals 48, the input terminal 112 is provided on the upper electrode layer 104 of the vibrator 42, the output terminal 114 is provided on the lower electrode layer 106 of the vibration detection sensor 44, the lower electrode layer 106 of the vibrator 42, and the vibration detection. A common ground terminal 116 is attached to each of the electrode layers joined to the upper electrode layer 104 of the sensor 44. For the three lead terminals 48, an appropriate metal wire can be used. In order to attach each of the three lead terminals 48 to the corresponding electrode layer, soldering or a conductive adhesive can be used.

  Returning to FIG. 4 again, the holding substrate 34 is a circuit board to which the probe elements 40 are attached in a two-dimensional arrangement. The holding substrate 34 is provided with a connection hole 36 into which the tip portions of the three lead terminals 48 attached to each probe element 40 are inserted and soldered. These connection holes 36 are connected to a wiring pattern (not shown), and are drawn out to positions suitable for the subsequent processing by the wiring pattern. An appropriate circuit component 38 can be mounted on the holding substrate 34. As the holding substrate 34, a glass epoxy circuit board or the like can be used.

  The vibration insulating member 46 provided between the holding substrate 34 and each probe element 40 is a buffer material arranged so that free vibration of the vibrator 42 constituting the probe element 40 is not suppressed by the holding substrate 34. is there. As the vibration insulating member 46, for example, a urethane sheet made of urethane resin or urethane foam can be used. Plastic rubber composed of other materials may be used. As shown in FIG. 4, the vibration insulating member 46 may be provided for each probe element 40. In some cases, a single urethane sheet or the like may be provided across a plurality of probe elements 40. Good. The thickness of the vibration insulating member 46 can be, for example, about 0.2 mm to about 0.5 mm.

  The contact sheet 32 is a thin protective sheet disposed on the contact surface side of the plurality of probe elements 40 attached to the holding substrate 34. As the contact sheet 32, a silicon sheet made of silicon resin or the like can be used. Plastic sheets made of other materials may be used. The thickness of the contact sheet 32 can be about 0.2 mm to about 0.5 mm, for example.

  Since the probe unit 20 has been described above, returning to FIG. 2 again, the details of the configuration of the main body unit 60 will be described below. In the following, elements similar to those in FIGS. 1 and 3 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted. In the following, description will be made with reference to FIGS. 1 and 3 to 6.

  In the main body 60, the hardness calculation switching circuit 62 is a circuit having a function of selecting the probe element 40 connected to the hardness calculator 70 from the plurality of probe elements 40. The hardness calculation switching circuit 62 includes a changeover switch group 64 and a change control unit 66 that controls the operation of the changeover switch group 64. The change-over switch group 64 sequentially switches the signal lines from the transducers 42 and the signal lines from the vibration detection sensors 44 constituting the plurality of probe elements 40 by a plurality of switches to the hardness calculator 70. A switch circuit to be connected. A semiconductor switch can be used as the switch.

  The switching control unit 66 controls the sequential switching of connections in each switch constituting the selector switch group 64. As a method of sequential switching control, sequential switching for each probe element 40 is performed, for example, an address is assigned to each probe element 40, and connection to the hardness calculator 70 is performed in the order of addresses. it can.

  As described above, the hardness calculation switching circuit 62 connects the signal line of the transducer 42 and the signal line of the vibration detection sensor 44 to the hardness calculator 70 for one selected probe element 40. The

  The hardness calculator 70 includes a terminal 72 that receives an output signal from the vibration detection sensor 44, a terminal 74 that outputs an input signal to the vibrator 42, and a terminal 76 that outputs data of the calculated hardness. The inside of the hardness calculator 70 is configured as follows.

  A terminal 72 connected to the vibration detection sensor 44 is connected to an amplifier 82 via an appropriate DC cut capacitor 80. An output of the amplifier 82 is input to a phase shift circuit 84, and an output of the phase shift circuit 84 is a terminal. It is connected to the vibrator 42 through 74. In this way, a closed loop of the vibrator 42-the biological tissue 8 to be measured-the vibration detection sensor 44-the amplifier 82-the phase shift circuit 84-the vibrator 42 is configured.

  The closed-loop resonance frequency output from the phase shift circuit 84 is input to the hardness calculator 86. The hardness calculator 86 includes a frequency change amount calculation module 88 and a hardness output module 90. The frequency change amount calculation module 88 calculates the change amount of the resonance frequency of the closed loop before and after the probe unit 20 contacts the living tissue 8, and inputs the change amount to the hardness output module 90. The hardness output module 90 is obtained in advance. The frequency change amount is converted into hardness based on the correlation, and is output to the terminal 76 as the hardness of each probe element 40.

  The amplifier 82 is an electronic circuit that appropriately amplifies the signal detected by the vibration detection sensor 44, and a known amplifier circuit can be used.

  The phase shift circuit 84 is provided between the output end of the amplifier 82 and the input end of the vibrator 42. When a phase difference occurs between the input waveform to the vibrator 42 and the output waveform from the vibration detection sensor 44, the phase shift circuit 84 The phase difference has a function of changing the frequency to shift to zero and maintaining the resonance of the closed loop circuit. Since details of the phase shift circuit 84 are described in the above-mentioned Patent Document 2, here, the input waveform and vibration detection of the vibrator 42 are sized according to the hardness of the biological tissue 8 to be measured. A phase difference occurs in the output waveform of the sensor 44, and the phase shift circuit 84 will only be described to change the closed-loop resonance frequency so that the phase difference is zero.

Therefore, the closed-loop resonance frequency f ₁ when the phase difference between the input waveform of the transducer 42 and the output waveform of the vibration detection sensor 44 is zero before the probe element 40 contacts the living tissue 8 is obtained. feeler element 40 determine the resonance frequency f ₂ of the closed loop when the phase difference between the output waveform of the input waveform and the vibration sensor 44 of the transducer 42 and to zero after the contact with the living body tissue 8. Then, the obtained frequencies f ₁ and f ₂ are input to the frequency change amount calculation module 88 of the hardness calculation unit 86.

The frequency change amount calculation module 88 has a function of calculating a frequency change amount Δf = f ₂ −f ₁ from the two input frequencies f ₁ and f ₂ .

  The hardness output module 90 obtains a relationship between the magnitude of the frequency change amount Δf and the hardness in advance, and uses this as a conversion relationship from the frequency change amount Δf to the hardness. Based on this conversion relationship, It has a function of outputting as the hardness of the tissue 8. The conversion relationship can be obtained in advance by experiments or the like, stored in an appropriate storage device, and read out as necessary. For example, the hardness of a standard biological tissue is obtained by a separate method, the frequency change amount Δf is obtained for the same biological tissue with a hardness measurement device using a phase shift method, and the correlation between the frequency change amount Δf and the hardness is obtained in advance. Can be prepared. The hardness converted based on the conversion relationship is output from the terminal 76 to the display processing unit 92 as the hardness of the portion in contact with the corresponding probe element 40.

  The display processing unit 92 cooperates with the switching control unit 66 to associate the hardness output from the terminal 76 with the two-dimensional position of the corresponding probe element 40 and to store the hardness data of each probe element 40. It has a function of performing conversion processing corresponding to two-dimensional display. The converted data is output to a two-dimensional hardness display 94, where the converted data is displayed as a two-dimensional hardness distribution.

  The operation of the two-dimensional hardness measuring apparatus 10 having such a configuration, in particular, the operation of the probe element 40 will be described in comparison with the prior art. FIG. 7 is a diagram showing a comparison between the configuration and operation of the prior art and the configuration and operation described in FIG. 2. FIG. 7 (a) shows the configuration and operation of Patent Document 1, and FIG. The configuration and operation of the probe element 40 in FIG. 2 are shown. In the following, the same elements as those in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted. In the following, description will be made using the reference numerals in FIGS. In FIG. 7A, for comparison, the reference numerals and terms described in Patent Document 1 are different, but the same reference numerals are given to the same elements as those in FIG. 2, and the terms in FIG. It explains using.

  In FIG. 7A, the probe element 40 includes a transducer 42 and a vibration detection sensor 44 that are stacked, and is attached to the holding substrate 34 via the mount 120. A substantially hemispherical ball 122 is attached to the side in contact with the living tissue 8. The mounting base 120 is provided with a pressure sensor 124 for detecting the pressing pressure. With such a configuration, when the entire body tissue 8 is pressed against the living tissue 8, the living tissue 8 is deformed from the natural surface NN while being recessed into a substantially hemispherical shape in response to the pushing of the substantially hemispherical ball 122. To do. Therefore, when the contact depth is shallow, the contact area between the ball 122 and the living tissue 8 is small, and the contact area between the ball 122 and the living tissue 8 increases as the contact depth increases.

  From this, when the contact depth differs among the probe elements 40, it is considered that the detected hardness varies. In the configuration of FIG. 7A, the pressure sensor 124 is used to display only the hardness data of the probe element 40 that falls within a predetermined indentation pressure range, so that the hardness data varies due to the difference in contact depth. Suppressed.

  FIG. 7B illustrates a configuration around the probe element 40 described in FIG. As described above, both the vibration detection sensor 44 and the vibrator 42 constituting the probe element 40 are formed by cutting the vibrator plate 100 vertically and horizontally in a plane. Therefore, the contact surface of the vibration detection sensor 44 facing the contact sheet 32 has a flat contact surface shape in a direction perpendicular to the press contact direction. With such a configuration, when the whole body tissue 8 is pressed into contact with the living tissue 8, the living tissue 8 is deformed from the natural surface NN in the flat surface according to the pressing of the flat surface of the vibration detection sensor 44. . Therefore, even if the contact depth changes, the contact area between the contact surface of the vibration detection sensor 44, which is the tip surface of the probe element 40, and the living tissue 8 is always the same. From this, even if the contact depth is different, the difference in hardness based on the difference in contact area is suppressed.

  As described above, the vibration detecting sensor 44 and the vibrator 42 formed by cutting the flat vibrator plate vertically and horizontally in the plane are laminated to form the probe element 40, and thus the two-dimensional structure using the probe element 40 is obtained. The cost of the mechanical hardness measuring apparatus 10 can be reduced, and at the same time, the influence of the pressure welding method can be reduced.

It is a figure which shows the whole structure of the two-dimensional hardness measuring apparatus in embodiment which concerns on this invention. It is a block diagram which shows the structure of the hardness measuring apparatus in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a perspective view of a probe body. In embodiment which concerns on this invention, it is a partial expanded sectional view which shows the mode of the probe element assembly. FIG. 10 is a diagram for explaining a method for manufacturing a vibrator in the embodiment according to the invention. In an embodiment concerning the present invention, it is a figure showing signs that a probe is formed by laminating a vibration detection sensor and a vibrator, and a lead terminal is attached. It is a figure which shows the structure and effect | action of embodiment which concerns on this invention compared with the structure and effect | action of a prior art.

Explanation of symbols

  8 biological tissue, 10 hardness measuring device, 20 probe portion, 22 tip portion, 24 gripping portion, 26 pressure contact surface, 30 probe element assembly, 32 contact sheet, 34 holding substrate, 36 connection hole, 38 circuit component, 40 Probe element, 42 vibrator, 44 vibration detection sensor, 46 vibration insulation member, 48 lead terminal, 50 interface circuit, 60 body part, 62 hardness calculation switching circuit, 64 changeover switch group, 66 changeover control part, 70 hardness Calculator, 72, 74, 76 terminals, 80 DC cut capacitor, 82 amplifier, 84 phase shift circuit, 86 hardness calculation unit, 88 frequency variation calculation module, 90 hardness output module, 92 display processing unit, 94 two-dimensional Hardness indicator, 100 vibrator plate, 102 piezoelectric material layer, 104 top electrode layer, 106 bottom electrode layer, 112 inputs Terminal, 114 output terminal, 116 common ground terminal, 120 mounting base, 122 ball, 124 pressure sensor.

Claims (5)

A plurality of probe elements that are press-contacted to the measurement target via a contact sheet, each of which includes a transducer that enters the measurement target and a vibration that detects a reflected wave from the measurement target A plurality of probe elements each having a detection sensor;
Lead terminals drawn from the vibrator and the vibration detection sensor,
A circuit board including wiring to which each lead terminal is connected, and while arranging a vibration insulating member between a plurality of probe elements, each lead terminal from each probe element is connected to a corresponding wiring, A holding substrate for arranging and holding a plurality of probe elements in a two-dimensional array ;
Provided between the signal output terminal of the signal input terminal of vibration Doko vibration detection sensor, and hardness calculator for calculating a hardness of the object to be measured of the parts in contact with the feeler element,
A hardness calculation switching circuit for sequentially switching the connection between each probe element and the hardness calculator;
A display for two-dimensionally displaying the hardness calculated for each probe element;
With
The hardness calculator
An amplifier having an input terminal connected to a signal output terminal of the vibration detection sensor;
Provided between the output terminal of the amplifier and the signal input terminal of the vibrator, and forms a closed loop circuit together with the vibrator, vibration detection sensor and amplifier, and the phase difference between the input waveform to the vibrator and the output waveform from the vibration detection sensor When this occurs, a phase shift circuit that changes the frequency of the phase difference and shifts it to zero to maintain the resonance of the closed loop circuit;
A hardness output means for detecting a frequency change amount for shifting the phase difference to zero, calculating a hardness from the detected frequency change amount, and outputting it;
Including
Each of the probe elements has a contact surface shape that makes contact with a constant contact area regardless of the pressure contact depth. The two-dimensional hardness measuring apparatus according to claim 1,
Each probe element has a flat contact surface shape in a direction perpendicular to the pressure contact direction. The two-dimensional hardness measuring apparatus according to claim 1,
Each probe element has a two-dimensional hardness measuring device in which a transducer and a vibration detection sensor are stacked in a direction perpendicular to the pressure contact direction. The two-dimensional hardness measuring apparatus according to claim 1,
The vibrator has a rectangular planar shape formed by dividing a flat vibrator plate vertically and horizontally in a plane,
The vibration detection sensor has a rectangular planar shape formed by dividing a flat vibration detection sensor plate vertically and horizontally in a plane, and a two-dimensional hardness measuring device. The two-dimensional hardness measuring apparatus according to claim 1,
The holding substrate is a circuit board on which at least a part of circuit elements constituting a hardness calculator and a hardness calculation switching circuit is mounted.

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