JP2005111280A - Touch sensation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a user-friendly touch sensation sensor which measures hardness of a viable tissue by a change in the frequency of ultrasonic waves over a wide range. <P>SOLUTION: The touch sensation sensor has a plurality of ultrasonic vibrator transducers 53 to detect a change in resonance characteristics of ultrasonic vibration when making a touch sensation sensor probe 50 touch on a viable tissue to turn the result into the information of hardness of the viable tissue. The ultrasonic vibrator transducers 53 are positioned in the touch sensation sensor probe 50 movably along a touch part 52 for measurement to detect hardness in a plurality of positions of the viable tissue on which the touch part 52 for measurement is made to touch. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tactile sensor that is brought into contact with an object such as a living body and detects the hardness at the contact portion.

  As a prior art of this type of tactile sensor, first, there is a hardness sensor disclosed in Japanese Patent Laid-Open No. 2-290529 (Patent Document 1). This hardness sensor is provided with a piezoelectric element on the diaphragm that comes into contact with an object, and this piezoelectric element is connected to a transmission circuit and a detection circuit that detects a change in resonance frequency that occurs when the object touches the object. The hardness of the object is measured by the output from the circuit.

Japanese Patent Publication No. 40-27236 (Patent Document 2) proposes a flexibility measuring device. This device converts electrical energy from an ultrasonic oscillator into ultrasonic vibration energy via a piezoelectric element and applies this ultrasonic vibration energy to a metal needle, while mechanically reacting to the ultrasonic vibration at the tip of the metal needle. A change in load is taken out as a change in acoustic impedance in the piezoelectric element, and the degree of flexibility of the object hit by the tip of the metal needle is measured.
JP-A-2-290529 Japanese Patent Publication No. 40-27236

In these conventional examples, the measurement location is a point or a very narrow surface, and in any case, it is not possible to know the hardness in a wide surface.
When using such a measuring apparatus to obtain hardness information in a broad surface, it is necessary to manually move the sensing portion including the piezoelectric vibrator. However, at that time, the amount of pressing force on the measurement object greatly fluctuates. Moreover, if the amount of pressing force changes greatly, naturally the hardness of the pressed part will also change and it will become difficult to obtain the information as the same conditions.

  Furthermore, especially when the target object is a living body, there are many inherently flexible tissues, and it is practically difficult to move the piezoelectric element in a wide area by severe measurement, that is, uniform pressing. It requires considerable skill to move the sensor tip having a small contact area with a uniform force over a certain range. Moreover, it is difficult to obtain an accurate measurement result although careful operation and a lot of time are required.

  An object of the present invention is to provide a tactile sensor with good operability for measuring the hardness measurement of a living tissue by changing the frequency of ultrasonic waves over a wide range.

The invention according to claim 1 includes a tactile sensor probe having a measurement contact portion that comes into contact with a biological tissue, including an ultrasonic transducer, and the ultrasonic vibration when the measurement contact portion is brought into contact with the biological tissue. A tactile sensor having detection means for detecting a change in the resonance characteristics of the ultrasonic vibration of the child and making it a hardness information of the biological tissue,
The ultrasonic transducer is arranged on the tactile sensor probe so as to be movable along the surface of the measurement contact portion that is brought into contact with the biological tissue, and is hardened at a plurality of positions of the biological tissue in contact with the measurement contact portion. It is a tactile sensor characterized by detecting the height.
According to a second aspect of the present invention, there is provided a tactile sensor probe having a measurement contact portion that comes into contact with a biological tissue, including an ultrasonic transducer, and the ultrasonic vibration when the measurement contact portion is brought into contact with the biological tissue. A tactile sensor having detection means for detecting a change in the resonance characteristics of the ultrasonic vibration of the child and making it a hardness information of the biological tissue,
The ultrasonic transducer is a plurality of ultrasonic transducers arranged on the tactile sensor probe along the surface of the measurement contact portion to be brought into contact with the living tissue, and the living body with which the measurement contact portion is contacted A tactile sensor that detects hardness at a plurality of positions of a tissue.
According to a third aspect of the present invention, there is provided a tactile sensor probe having a measurement contact portion that comes into contact with a biological tissue, including an ultrasonic transducer, and ultrasonic vibration when the measurement contact portion is brought into contact with the biological tissue. A tactile sensor having detection means for detecting a change in resonance characteristics and using this as information on the hardness of a living tissue,
The tactile sensor probe includes a rotating substantially cylindrical drum, a measurement contact portion disposed on a peripheral side surface of the drum, and a plurality of ultrasonic waves radially disposed on the drum along the measurement contact portion. A tactile sensor comprising a vibrator.

  According to the present invention, it is possible to provide a tactile sensor with good operability for measuring the hardness measurement of a living tissue by changing the frequency of ultrasonic waves over a wide range.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

(the purpose)
The purpose of this embodiment is to obtain information on changes in hardness mainly over a wide range of surfaces in a short time, and can be inserted into a body cavity in a less invasive state with respect to the human body. It is intended to obtain information on hardness change by direct contact.

(Constitution)
FIG. 1 shows an overview of a tactile sensor system. The system includes a tactile sensor probe 1 and a probe control unit 2 that are brought into contact with a living body. The probe 1 has a distal end portion 3 to be brought into contact with a living body, an elastic bending portion 4 that allows the orientation of the distal end portion 3 to be changed, an insertion tube 5 that follows this, and a drive unit 6 provided at the proximal end of the insertion tube 5. And a grip portion 7 required for operation, and a cable 8 for exchanging signals with the probe control portion 2 is connected to the grip portion 7 of the probe 1. A sensor portion 10 having an ultrasonic transducer 9 accommodated in the side surface portion of the tip portion 3 of the probe 1 is provided. A signal line 11 is connected to the ultrasonic transducer 9.

  In the probe 1, the outer diameters of the tip part 3, the elastic bending part 4, and the insertion tube 5 connected in series are substantially the same diameter, and these parts are interposed through an outer tube 12 such as a trocar as shown in FIG. 2. Can be inserted into the body cavity. The distal end portion 3 and the elastic bending portion 4 are fixed to the insertion tube 5 via a bearing portion 13 so as to be rotatable. The insertion tube 5 is fixed to the case 14 of the drive unit 6.

  In the case 14, a rotational drive source 16 connected to the drive force transmission shaft 15 is disposed. The driving force transmission shaft 15 is inserted through the insertion tube 5, and the tip of the driving force transmission shaft 15 is fixed to the bending portion 4. The signal line 11 is disposed in the driving force transmission shaft 15. The tip portion 3 and the elastic bending portion 4 are operated by the rotational driving source 16 via the driving force transmission shaft 15 and rotate around the insertion tube 5, that is, the sensor portion 10 serves as a measurement contact portion. This constitutes a driving means for two-dimensionally smoothing the region on which the ultrasonic transducer 9 acts on the surface of the living tissue with which it comes into contact.

  In the driving unit 6, an encoder 17 for obtaining rotation information of the driving force transmission shaft 15 and a slip ring 18 for relaying an electrical signal with the sensor unit 10 through the signal line 11 are provided.

  On the other hand, the probe control unit 2 in this system is roughly divided as follows. That is, an ultrasonic drive unit 21 for sending an ultrasonic drive signal to the sensor unit 10 housed in the tip 3 of the probe 1, and a frequency count unit 22 for measuring the resonance frequency detected by the sensor unit 10. The display unit 23 for displaying the frequency change measured by the frequency count unit 22 or the corresponding hardness of the living tissue site, and the scanning for controlling the rotary drive source 16 for scanning the tip 3. The control unit 24.

(Action / Effect)
When using this probe 1, as shown in FIG. 2, the distal end portion 3 of the probe 1 is inserted into the body cavity through the outer tube 12 previously punctured into the body cavity wall 25, and the elastic bending portion 4 is bent to be inserted into the insertion tube 5. On the other hand, the tip 3 is set at a substantially right angle, and the sensor 10 is brought into contact with the surface of the biological tissue site 26 in the body cavity.

  When the rotational force of the rotational drive source 16 is transmitted to the distal end portion 3 and the elastic bending portion 4 through the driving force transmission shaft 15, the distal end portion 3 and the elastic bending portion 4 are centered on the insertion tube 5 while maintaining the bent state. Rotate as shown by the arrow. That is, the tip 3 is moved while the sensor unit 10 is always in contact with the surface of the biological tissue site 26 due to the elasticity of the elastic bending portion 4, so that the sensor unit 10 makes the surface of the biological tissue site 26 annular. Scan. At this time, the resonance frequency detected by the sensor unit 10 is measured by the frequency count unit 22. In general, the softer the frequency change, the larger the amount of change with respect to the frequency in the air. Therefore, the hardness of the biological tissue portion corresponding to the detected change in frequency can be measured.

  In other words, the sensor unit 10 serves as a measurement contact unit, and is driven so that the region on which the ultrasonic transducer 9 acts is two-dimensionally aligned on the surface of the living tissue with which the sensor unit 10 contacts. As a result, information on the change in hardness can be obtained over a wide range of the biological tissue site. Furthermore, it is possible to associate the hardness information with the position information sequentially operated by the encoder 17, and in this way, the hardness information of each position over a wide range can be obtained individually.

  Further, since the probe 1 can be inserted through an outer tube 12 such as a trocar, there is little invasiveness to the subject, and the distal end portion 3 is bent with respect to the insertion tube 5 in the body cavity and then the distal end portion thereof. 3 can be rotated, so that the hardness can be measured efficiently in a wide range as compared with the outer diameter of the outer tube 12. Furthermore, it became possible to apply the sensor part 10 more directly to the target site by inserting it into the body cavity.

  In addition, the sensor portion 10 is always urged by an appropriate pressure by the elastic bending portion 4, the contact pressure is stabilized, and the accuracy of hardness measurement can be increased.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIG.

(the purpose)
The purpose of this embodiment is to make it possible to provide information on hardness changes for a wide range of surfaces in a relatively short time with a simple configuration, and to provide an inexpensive system. is there.

(Constitution)
The probe 30 of this embodiment includes a housing 31. An elastic film body 32 such as silicon rubber is stretched on the front opening of the housing 31. Inside the housing 31, there is provided a sensor unit portion 36 that is unitized from an ultrasonic transducer 33 and a vibration propagating body 34. The vibration propagating body 34 has a tip portion 37 formed in a conical shape with a slight roundness at the tip. A ball screw 38 is disposed inside the housing 31 in parallel with the surface of the film body 32, and a stepping motor 39 for driving the ball screw 38 is provided on one side of the housing 31. The rotation information of the ball screw 38 by the stepping motor 39 is obtained by the encoder 40.

  The unitized sensor unit 36 is supported by a ball screw 38 and can be moved in the horizontal direction on the drawing, that is, along the surface of the film body 32 by the rotation of the ball screw 38. That is, the driving means is configured to two-dimensionalize the region where the ultrasonic transducer acts on the surface of the living tissue. The tip 37 of the vibration propagating body 34 of the sensor unit 36 is provided so as to be in smooth contact with the inner surface of the film body 32 during this movement. Transmission / reception of signals for the ultrasonic transducer 33 is performed by a stretchable signal cable 41 wound in a coil shape.

  The signal cable 41 is led to the probe control unit as described above together with the drive signal cable 42 to the stepping motor 39. The probe control unit includes an ultrasonic drive unit for sending an ultrasonic drive signal to the sensor unit 36, a frequency count unit for measuring the resonance frequency detected by the sensor unit 36, and the frequency count unit. In addition, a display unit for displaying the change in frequency and a scanning control unit for controlling the stepping motor 39 as a rotational drive source for scanning the sensor unit 36 are provided. The rotation information of the ball screw 38 obtained by the encoder 40 is also transmitted to the probe control unit.

(Action / Effect)
When using the probe 30 of this embodiment, as shown in FIG. 3, the membrane body 32 is previously applied to the surface of the biological tissue site 44. Then, a command is given to the probe control unit to drive the stepping motor 39, and the ball screw 38 is rotated to move the sensor unit unit 36 along the film body 32. The distal end portion 37 of the vibration propagating body 34 in the sensor unit 36 moves so as to be in smooth contact with the inner surface of the membrane body 32, presses against the surface of the biological tissue site 44 via the membrane body 32, and moves linearly. Perform a dimensional scan. Thereby, the information of the hardness change over a wide range is obtained. Furthermore, the encoder 40 can also associate the hardness information with the position information, and in this way, the hardness information at each position over a wide range can be obtained individually.

  According to this embodiment, since a method of obtaining hardness information while mechanically scanning a single ultrasonic transducer is employed, it is not necessary to correct individual differences in the ultrasonic transducer. Therefore, the accuracy in measuring the frequency change is good.

  In addition, since there are few wires and the structure is simple, an inexpensive probe can be realized. Furthermore, since the circuit in the probe control unit is also simplified, the system becomes inexpensive.

  In addition, since the film body is stretched against the housing that is molded to match the horizontal scanning width, it is possible to uniformly press within the scanning range by applying this probe to the test object. Yes, the accuracy of measuring the test object is improved.

  Note that the probe of this embodiment can be configured to be relatively small so as to be used by being introduced into a body cavity, and can also be used for measuring the hardness of living tissue in the body cavity.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIG.

(the purpose)
The purpose of this embodiment is to provide a system that can obtain a wide range of surface hardness change information with a relatively simple structure in a short time and with relatively high accuracy, and to provide a probe that is inexpensive and resistant to failure. There is to be able to do it.

(Constitution)
The probe 50 of this embodiment includes a housing 51. An elastic film body 52 such as silicon rubber is stretched on the front opening of the housing 51. Inside the housing 51, a plurality of sensor unit portions 56 having the same configuration, which are unitized from the ultrasonic transducer 53 and the vibration propagating body 54, are arranged and fixedly arranged. The vibration propagating body 54 of the sensor unit 56 has a tip portion 57 formed in a conical shape with a slight roundness at the tip. The plurality of sensor unit portions 56 are arranged adjacent to each other in a row and in parallel with each other so that the front end portion 57 of the vibration propagating body 54 abuts against the inner surface of the film body 52. That is, the driving means is configured to two-dimensionalize the region where the ultrasonic transducer 53 acts on the surface of the living tissue.

  The supply of the signal to the ultrasonic transducer 53 is guided to the probe control unit as described above via the cable unit 58. The probe control unit includes an ultrasonic drive unit for sending an ultrasonic drive signal to each sensor unit 56, a frequency count unit for measuring the resonance frequency detected by each sensor unit 56, and the frequency count unit. A display unit or the like for displaying the frequency change measured in (1) is provided.

  Note that the ultrasonic drive units may be built in as many as the number of ultrasonic transducers 53, or the number of drive units may be reduced from the number of ultrasonic transducers 53 using a drive signal switching circuit.

(Action / Effect)
When using the probe 50 of this embodiment, the membrane body 52 is applied to the surface of the biological tissue site. Then, a command is given to the probe control unit to drive the ultrasonic transducer 53 of each sensor unit unit 56, and the resonance frequency detected by each sensor unit unit 56 is measured. Information on the change in hardness can be obtained from the difference in resonance frequency. Each sensor unit 56 is two-dimensionally arranged in a line, and therefore, information on the change in hardness over a wide range can be obtained.

  Hardness information at each position corresponding to each sensor unit 56 can be obtained individually over a wide range.

  Since the ultrasonic transducers 53 of the plurality of sensor unit portions 56 can be driven almost simultaneously, measurement can be performed in a very short time. Therefore, there are few time restrictions with respect to a subject.

Since the housing 51 and the film body 52 have a certain area, uniform pressing can be obtained, and the hardness measurement accuracy can be improved.
Since the probe 50 itself does not have mechanically moving elements, it is difficult to break down once assembled.

<Fourth Embodiment>
The fourth embodiment of the present invention will be described with reference to FIGS.

(the purpose)
An object of this embodiment is to provide a system capable of obtaining hardness change information for a wide range of surfaces in a short time and with relatively high accuracy.

(Constitution)
The probe 60 of this embodiment includes a drum 63 that is rotatable with respect to a main body 62 having a handle 61. The drum 63 has a slip ring 64. In the drum 63, a cylindrical film body 66 having elasticity, such as silicon rubber, is stretched on a part of the cylindrical housing 65, and a plurality of sensor unit portions 67 are radially arranged therein. As in the third embodiment, the sensor unit 67 has the same configuration as a unit composed of the ultrasonic vibrator 68 and the vibration propagating body 69, and the membrane 70 is disposed with the tip 70 of the vibration propagating body 69 facing outward. It is made to touch the inner surface of the body 66. By incorporating a plurality of sensor unit portions 67 into the drum 63, a driving means is configured to two-dimensionalize the region where the ultrasonic transducer 68 acts on the surface of the living tissue. The plurality of sensor unit parts 67 are arranged radially at equal intervals around the rotation center of the drum 63. However, in order to increase the number of sensor unit parts 67 and arrange them densely, adjacent to the center side base part. The side part 71 is narrowed narrowly and closely abutted.

  The cable portion 72 connected to the ultrasonic vibrator 68 is bundled toward the cylindrical center of the drum 63, connected to the slip ring 64 shown in FIG. 5, and electrically connected to the cable portion 72 inserted through the handle 61. Has been. The cable part 72 is led out from the end face of the handle 61 and connected to the probe control part described above.

  The probe control unit includes an ultrasonic drive unit for sending an ultrasonic drive signal to each sensor unit 67, a frequency count unit for measuring a resonance frequency detected by each sensor unit 67, and a frequency count unit. A display unit or the like for displaying the measured frequency change is provided.

  It should be noted that the ultrasonic drive units may be built in as many as the number of ultrasonic transducers 68, or the number of drive units may be reduced from the number of sensor unit portions 67 using a drive signal switching circuit.

(Action / Effect)
When the probe 60 of this embodiment is used, the drum 63 is brought into contact with the surface of the living tissue site and rolled. And the ultrasonic transducer | vibrator 68 of each sensor unit part 67 is driven, and the resonant frequency detected by each sensor unit part 67 is measured. Information on the change in hardness can be obtained from the difference in resonance frequency. Each sensor unit 67 is arranged radially on the rotating drum 63, and information on hardness change over a wide range can be obtained by rolling against the surface of the biological tissue site. Further, the hardness information at each position corresponding to each sensor unit 67 can be obtained over a wide range.

  Further, by holding the handle 61 and rolling the drum 63, it is possible to measure the hardness in a two-dimensional manner while always pressing the object on a wide surface including the housing 65 without causing the single sensor unit 67 to make point contact. In addition, since the drum 63 is rolled, the pressing pressure is less likely to vary, and information on the change in hardness can be obtained with high accuracy.

<Modification>
In the third and fourth embodiments described above, the sensor unit units are arranged in a line, but the sensor unit units may be arranged in a plurality of columns. In this way, since many sensor unit parts can be opposed to the measurement site at a time, it is possible to measure a wide range in a shorter time.

  Next, another example of the tactile sensor system will be described with reference to FIGS.

(Constitution)
FIG. 7 shows a schematic configuration of a tactile sensor system according to this example, which includes a tactile sensor probe 82 introduced into a body cavity through the endoscope 81 and a probe control unit 83. .

  The tactile sensor probe 82 includes a long and flexible insertion portion 84, and a sensor unit portion as shown in FIG. 8 is incorporated in the distal end portion 85 of the insertion portion 84. That is, a cylindrical ultrasonic transducer 86 is provided at the distal end portion 85 in a state of being coaxially disposed with respect to the long axis of the insertion portion 84, and the ultrasonic transducer 86 is in close contact with the distal end cover 87. Coaxially covered. The outer peripheral side surface of the tip cover 87 forms a contact portion 88 that comes into contact with, for example, a luminal organ. As shown in FIG. 8B, the cylindrical ultrasonic transducer 86 is polarized so as to vibrate in the radial direction x with respect to its central axis. The ultrasonic vibrator 86 and the contact portion 88 are integrated by self-excited oscillation to vibrate in the radial direction x by the resonance frequency.

  A signal line 89 is connected to the electrode of the ultrasonic transducer 86. The signal line 89 is guided to the hand side through the insertion portion 84 and then connected to the probe control portion 83 through the signal cable 91. Further, an operation switch 92 for operating the oscillation operation is provided at the hand of the tactile sensor probe 82. The surgeon can arbitrarily operate the operation switch 92.

  The probe control unit 83 is provided with an oscillation circuit 93 that oscillates a signal for causing the ultrasonic transducer 86 to vibrate at a resonance frequency. A frequency detection circuit 94 and a voltage detection circuit 95 are connected to the oscillation circuit 93 and constitute monitoring means for monitoring changes in resonance frequency and changes in mechanical impedance.

(Function)
When the hardness of a luminal organ is measured using this tactile sensor system and the position of a lesion is to be identified, this is performed as follows. First, the tactile sensor probe 82 is guided through the channel of the endoscope 81 that has been inserted into the body cavity in advance, and the distal end portion 85 of the tactile sensor probe 82 is moved into the tubular organ 98 of the patient 97 under the observation of the endoscope 81. Insert into. FIG. 8A shows the state.

  Then, the inside of the organ 98 is moved while the contact portion 88 of the distal end portion 85 is in contact with the inner surface of the tubular organ 98. Here, when the surgeon operates the operation switch 92 to operate the oscillation circuit 93, the ultrasonic transducer 86 and the contact portion 88 integrally vibrate at the resonance frequency by a signal from the oscillation circuit 93. When the contact portion 88 contacts the organ 98, the mechanical impedance changes according to the hardness of the organ 98, and the resonance frequency of the contact portion 88 changes. However, since the oscillation circuit 93 performs self-excited oscillation, the resonance frequency Oscillation can be performed following the change. The change in the resonance frequency at this time is monitored by the frequency detection circuit 94, and the voltage change is monitored by the voltage detection circuit 95. The change information of the hardness of the organ 98 can be obtained from at least one of these pieces of information. For example, the position of the lesioned part 99 localized under the mucous membrane of the organ 98 can be identified by the change information of the hardness.

(effect)
According to the tactile sensor probe 82 of this embodiment, the hardness characteristic in the direction perpendicular to the insertion direction of the tactile sensor probe 82 is measured as a change in frequency or voltage. Therefore, it is possible to exhibit excellent operability for determining the presence of the lesioned part 99.

  An example of a tactile sensor system will be described with reference to FIGS. 9 and 10.

(Constitution)
FIG. 9 shows a schematic configuration of a tactile sensor system according to this example, which includes a tactile sensor probe 102 and a probe control unit 103 introduced into a body cavity through a trocar mantle tube 101. . Separately, a rigid endoscope 105 that is introduced into the body cavity through the trocar cannula 104 is prepared.

  The tactile sensor probe 102 includes a long rigid insertion portion 106, and a sensor unit portion as shown in FIG. That is, a cylindrical ultrasonic transducer 108 is provided at the distal end portion 107 in a state of being coaxially disposed with respect to the long axis of the insertion portion 106. The ultrasonic transducer 108 is polarized so as to vibrate in the central axis direction X of the distal end portion 107. Further, the ultrasonic transducer 108 has a vibration angle conversion element 109 that also serves as a tactile contact portion at the tip thereof. The vibration angle conversion element 109 reflects the vibration received from the ultrasonic vibrator 108 inside, and converts the vibration direction to a diagonally forward direction having a specific angle with the central axis direction X. The distal end portion of the vibration angle conversion element 109 protrudes from the hole 112 of the cover 111, and the tip portion thereof forms a contact portion 113 that is slightly rounded.

  A signal line 114 is connected to the electrode of the ultrasonic transducer 108. The signal line 114 is guided to the hand side through the insertion unit 106 and then connected to the probe control unit 103 through the signal cable 115. In addition, an operation switch 116 for operating the oscillation operation is provided at the hand of the tactile sensor probe 102. The surgeon can arbitrarily operate the operation switch 116.

  The probe control unit 103 is provided with an oscillation circuit 93 that oscillates a signal for causing the ultrasonic transducer 108 to vibrate at a resonance frequency. The oscillation circuit 93 is connected to a frequency detection circuit 94 and a voltage detection circuit 95, and constitutes means for monitoring changes in resonance frequency and changes in mechanical impedance.

(Function)
When the hardness of an intra-abdominal organ is measured using this tactile sensor system and the position of a lesion is to be identified, it is as follows. The tactile sensor probe 102 is inserted into the abdominal cavity through the trocar cannula 101 and the contact portion 113 at the tip of the vibration angle conversion element 109 protruding obliquely is in contact with the surface of the organ 121 while observing with the rigid endoscope 105. Move on the surface of the organ 121. At this time, the operator operates the operation switch 116 to operate the oscillation circuit 93. The vibration angle conversion element 109 and the ultrasonic transducer 108 with the contact portion 113 integrally vibrate at the resonance frequency by a signal from the oscillation circuit 93. The tip end of the contact portion 113 projects obliquely forward with respect to the axis of the tactile sensor probe 102 and vibrates. For this reason, approach to the organ 121 which is obliquely forward of the tactile sensor probe 102 can be easily performed. The self-excited oscillation causes the ultrasonic transducer 108 and the vibration angle conversion element 109 to integrally vibrate at the resonance frequency. Further, as shown in FIG. 10, the contact portion 113 performs longitudinal vibration in the x direction perpendicular to the contact surface. When the contact portion 113 comes into contact with the organ 121, the mechanical impedance changes according to the hardness of the organ 121 and the resonance frequency of the contact portion 113 changes, but the oscillation circuit 93 performs self-oscillation. The oscillation follows the change in the resonance frequency. The change in the resonance frequency is monitored by the frequency change detection circuit 94, and the voltage change is monitored by the voltage detection circuit 95. At least one of these can be obtained as the change information of the hardness of the organ 121. For example, the position of the lesioned part 122 localized in the organ 121 can be identified by the change in hardness.

(effect)
Since the hardness can be measured with respect to the organ 121 obliquely in front of the tactile sensor probe 102, the operability thereof can be improved.

  An example of a tactile sensor probe will be described with reference to FIGS. 11 and 12.

(Constitution)
The tactile sensor probe 131 in this example is provided with thin film-like energy confinement type transducers 133 on both upper and lower side surfaces in the vicinity of the distal end portion of the body cavity insertion portion 132. The number of the energy confining type vibrators 133 may be one or plural, and the energy confining type vibrator 133 may be formed as one tubular thing.

  The energy confinement type vibrator 133 vibrates in the film thickness direction, but is attached so as to vibrate in a direction perpendicular to the axis of the tactile sensor probe 131. The outside is airtightly covered with a resin film such as silicon.

  This energy confinement type vibrator 133 is configured as shown in FIG. That is, the electrodes 136 are formed on both surfaces of the arc-shaped thin plate 135 of a piezoelectric element material such as ceramic, and the arc-shaped thin plate 135 is polarized in the film thickness direction. Further, the ultrasonic vibrator 133 and the contact portion 134 are united to perform self-excited oscillation at the resonance frequency, and vibrate in the radial direction x of the tactile sensor probe 131. The energy confinement type vibrator 133 can be formed by using, for example, a semiconductor manufacturing technique.

  A signal line 137 is connected to the electrode 136 of the energy confinement type vibrator 133. This signal line 137 is connected to the probe control unit as described above. In addition, an operation switch (in the drawing) for operating the oscillation operation is provided at the hand of the tactile sensor probe 131. The surgeon can arbitrarily operate the operation switch.

  The probe control unit is provided with an oscillation circuit that oscillates a signal for causing the energy confinement type vibrator 133 to vibrate at a resonance frequency. This oscillation circuit is connected to a frequency detection circuit and a voltage detection circuit, and constitutes a means for monitoring changes in resonance frequency and mechanical impedance.

(Function)
The tactile sensor probe 131 is inserted endoscopically into a luminal organ, and moves in the organ while the contact portion 134 is in contact with the inner surface of the organ. At this time, the surgeon operates the operation switch to operate the oscillation circuit. The ultrasonic vibrator 133 and the contact portion 134 integrally vibrate at a resonance frequency by a signal from the oscillation circuit. When the contact part 134 contacts the organ, the mechanical impedance changes according to the hardness of the organ, and the resonance frequency of the contact part 134 changes. However, since the oscillation circuit performs self-excited oscillation, the resonance frequency changes. Followed oscillation can be performed. The change of the resonance frequency is monitored by the frequency detection circuit, and the voltage change is monitored by the voltage detection circuit, and at least one of them can be obtained as change information of the hardness of the organ. From this, for example, the position of a lesion localized under the mucous membrane of an organ can be identified.

(effect)
According to the tactile sensor probe 131 of this embodiment, the hardness characteristic in the direction perpendicular to the insertion direction is measured as a change in frequency or voltage. Existence can be judged and excellent operability can be exhibited.

[Appendix]
1. A tactile sensor probe including at least one ultrasonic transducer and having a contact portion for measurement that comes into contact with a biological tissue, and resonance characteristics of the ultrasonic transducer when the measurement contact portion is brought into contact with the biological tissue If the area where the ultrasonic transducer acts on the surface of the biological tissue that contacts the measurement contact portion and the detection means for detecting the change in the amount and making this the information on the hardness of the biological tissue is two-dimensionally A tactile sensor comprising driving means for fastening. According to the present invention, information on changes in hardness over a wide range can be obtained in a short time and with high accuracy in a case where the hardness of a living tissue is measured by changing the frequency of ultrasonic waves over a wide range.
2. 2. The tactile sensor according to claim 1, wherein the driving means includes a plurality of ultrasonic transducers and is driven simultaneously.
3. 2. The tactile sensor according to claim 1, wherein the driving means includes a plurality of ultrasonic transducers, and the ultrasonic transducers are electrically switched and driven.
4). The tactile sensor according to item 1, wherein the driving means mechanically scans one ultrasonic transducer.
5). The tactile sensor according to appendix 1, wherein the driving means mechanically scans a plurality of ultrasonic transducers.
6). The tactile sensor according to item 1, wherein a plurality of ultrasonic transducers are provided, and these ultrasonic transducers are arranged in a straight line.
7). The tactile sensor according to item 1, further comprising a plurality of ultrasonic transducers, wherein the ultrasonic transducers are arranged in an annular shape.
8). The tactile sensor according to item 1, wherein a plurality of ultrasonic transducers are provided and the ultrasonic transducers are arranged in a matrix.
9. The drive means is provided with an elastic bending portion at the insertion portion of the probe that can be inserted into the body cavity, and the measurement contact portion including the ultrasonic transducer provided on the distal end side of the elastic bending portion is inserted in a curved state. The tactile sensor according to item 1, wherein the tactile sensor is rotated about a central axis of the portion.
10. A tactile sensor probe including at least one ultrasonic transducer and having a contact portion for measurement that comes into contact with a biological tissue, and resonance characteristics of the ultrasonic transducer when the measurement contact portion is brought into contact with the biological tissue In a tactile sensor equipped with a detection circuit for detecting a change in the amount and detecting this change as information on the hardness of a living tissue,
A tactile sensor characterized in that the vibration direction of ultrasonic vibration in the measurement unit is not parallel to the central axis of the tactile sensor probe.
11. Item 11. The tactile sensor according to item 10, wherein the ultrasonic transducer has a cylindrical shape and is polarized in a radial direction thereof.
12 The tactile sensor according to item 10, wherein a vibration direction changing member is disposed between the ultrasonic transducer and the measurement unit.
13. Item 11. The tactile sensor according to item 10, wherein the ultrasonic transducer is an energy confinement type transducer.
14 14. The tactile sensor according to item 13, wherein the energy confinement type vibrator is attached to a side surface of the probe.

(Appendix Nos. 10-14 and conventional problems)
There has been proposed a tactile sensor that measures the hardness of a living tissue by bringing a probe that vibrates ultrasonically into contact with the living tissue and detecting a change in the resonance frequency of the probe. Such a tactile sensor is used for identifying the position of a tumor localized under a mucous membrane in a body cavity by measuring the elasticity of the skin or using it under an endoscope.
However, in the conventional tactile sensor, since the ultrasonic transducer that vibrates in the axial direction integrated with the measurement unit is arranged on the axis of the tip of the probe, it is necessary to contact the measurement object in the axial direction of the probe. was there. For this reason, there is a problem that it is difficult to measure the tactile sensation of the living tissue existing on the side of the probe or obliquely forward, and the operability is very poor.
Appendices Nos. 10 to 14 provide tactile sensors with good operability that can measure the tactile sensation of living tissue located in various directions regardless of the insertion direction of the probe of the tactile sensor. According to this configuration, since the vibration direction of the ultrasonic vibration in the measurement unit is not parallel to the central axis of the probe, the ultrasonic vibration in the measurement unit is diagonally forward of the probe axis or the biological tissue on the side surface. Can be input in a direction perpendicular to the surface of the living body, and a tactile sensor with good operability can be obtained.

Explanatory drawing which shows the outline | summary of the system of the tactile sensor which concerns on 1st Embodiment. Similarly, explanatory drawing of the use state of the probe for tactile sensors. Explanatory drawing of the probe for tactile sensors which concerns on 2nd Embodiment. Explanatory drawing of the probe for tactile sensors which concerns on 3rd Embodiment. The perspective view of the probe for tactile sensors which concerns on 4th Embodiment. Similarly, the cross-sectional view of the probe for tactile sensors. Explanatory drawing which shows the outline | summary of the system of a tactile sensor. Similarly, explanatory drawing of the probe for tactile sensors. Explanatory drawing which shows the outline | summary of the system of another tactile sensor. Similarly, explanatory drawing of the probe for tactile sensors. Furthermore, explanatory drawing of another tactile sensor. Similarly, the perspective view of the energy confinement type vibrator.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Probe for tactile sensors, 2 ... Probe control part, 3 ... Tip part, 4 ... Elastic bending part, 5 ... Insertion tube, 6 ... Drive part, 9 ... Ultrasonic transducer, 10 ... Sensor part, 11 ... Signal line , 14, case, 15, driving force transmission shaft, 16, rotational drive source, 17, encoder, 18, slip ring, 21, ultrasonic drive unit, 22, frequency count unit, 24, scanning control unit.

Claims (3)

A tactile sensor probe including an ultrasonic transducer and having a measurement contact portion to be brought into contact with a living tissue;
Detecting means for detecting a change in the resonance characteristics of the ultrasonic vibration of the ultrasonic transducer when the measurement contact portion is brought into contact with the biological tissue, and setting this as hardness information of the biological tissue;
A tactile sensor comprising:
The ultrasonic transducer is arranged on the tactile sensor probe so as to be movable along the surface of the measurement contact portion that is brought into contact with the biological tissue, and is hardened at a plurality of positions of the biological tissue in contact with the measurement contact portion. A tactile sensor characterized by detecting the thickness. A tactile sensor probe including an ultrasonic transducer and having a measurement contact portion to be brought into contact with a living tissue;
Detecting means for detecting a change in the resonance characteristics of the ultrasonic vibration of the ultrasonic transducer when the measurement contact portion is brought into contact with the biological tissue, and setting this as hardness information of the biological tissue;
A tactile sensor comprising:
The ultrasonic transducer is a plurality of ultrasonic transducers arranged on the tactile sensor probe along the surface of the measurement contact portion to be brought into contact with the living tissue, and the living body with which the measurement contact portion is contacted A tactile sensor that detects hardness at a plurality of positions of a tissue. A tactile sensor probe including an ultrasonic transducer and having a measurement contact portion to be brought into contact with a living tissue;
Detecting means for detecting a change in the resonance characteristics of ultrasonic vibration when the measurement contact portion is brought into contact with the living tissue and using this as information on the hardness of the living tissue;
A tactile sensor comprising:
The tactile sensor probe includes a rotating substantially cylindrical drum,
A contact portion for measurement disposed on a peripheral side surface of the drum;
A plurality of ultrasonic transducers arranged radially on the drum along the contact portion for measurement;
A tactile sensor comprising:

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